bluuebunny/crossref_metadata_2025 huggingface dataset:
Ownership structure and audit quality: the mediating effect of board independence
Authors: Guizani Moncef , Abdalkrim Gaafar
Published: March 2021

Purpose

This study aims to examine the mediating effect of board independence on the relationship between ownership structure and audit quality.

Design/methodology/approach

The research uses generalized methods of moments regression to test the relationship between ownership structure and audit quality. The sample consists of 162 non-financial firms listed on the Gulf Cooperation Council stock markets between the years of 2009 and 2016. To test the significance of the mediating effect, this paper uses the Sobel test.

Findings

Empirical findings show that companies with higher family ownership are less likely to demand extensive audit services and, as a result, pay lower audit fees. Conversely, this study finds that companies with higher active and passive institutional ownership are more likely to engage high-quality auditors and pay larger audit fees. As for government ownership, it has no significant impact on audit fees. The results also reveal that the negative (positive) effect of family (institutional) ownership on audit quality follows the path through reducing (enhancing) board independence. Further tests are conducted and support the main findings.

Practical implications

This study has important implications for policymakers and regulators to address the conflict between controlling shareholders and minorities by promoting higher standards of audit quality. The study findings may be useful to investors, assisting them in making better-informed decisions and aids other interested parties in gaining a better understanding of the role played by ownership structure in audit quality. The study also contributes to the strategic board behavior by bringing a new perspective on how boards engage in monitoring by requesting external audit services. This behavior is likely to be influenced by the type of controlling shareholder.

Originality/value

The main contribution of the present paper is to examine the board composition as a potential mediating variable between ownership structure and audit quality. Moreover, it highlights the issue of improving governance mechanisms.
Regulation of Compensation and Systemic Risk: Evidence from the UK
Authors: KLEYMENOVA ANYA , TUNA İREM
Published: March 2021

This paper studies the consequences of regulating executive compensation at financial institutions by examining the introduction of the UK Remuneration Code in 2010, which aimed to change the decision‐making horizon and risk‐taking incentives of bank executives. We find that, although both banks and nonbanks show increased contribution and sensitivity to systemic risk in the United Kingdom post‐2010, this increase is lower for UK banks, in line with the intent of the regulation. However, UK banks also experience higher unforced CEO turnover when compared to other UK firms. Therefore, while the regulation may have had the desired effect on systemic risk, it may also have given rise to some unintended consequences.
Accounting conservatism and firm performance during the COVID‐19 pandemic
Authors: Cui Li , Kent Pamela , Kim Sujin , Li Shan
Published: March 2021

We explore whether firms with more conditionally conservative accounting practices have higher stock returns than other firms during the Covid‐19 outbreak. We find evidence that Chinese firms listed on the Shanghai and Shenzhen Stock Exchanges applying more conditionally conservative reporting have lower declines in stock return performance during the Covid‐19 outbreak relative to other firms. We also find that the beneficial role of conditional conservatism is higher when firms have greater information asymmetry following the Covid‐19 pandemic. Our results are robust to various model specifications with four different measures of conservatism and an alternative return window.
The learning curve of robot‐assisted vitreoretinal surgery – A randomized trial in a simulated setting
Authors: Jacobsen Mads F. , Konge Lars , la Cour Morten , Sørensen Rasmus B. , Park Yoon Soo , Thomsen Ann Sofia S.
Published: March 2021

Purpose

To investigate the learning curve of robot‐assisted vitreoretinal surgery compared to manual surgery in a simulated setting.

Methods

The study was designed as a randomized controlled longitudinal study. Eight ophthalmic trainees in the 1st or 2nd year of their specialization were included. The participants were randomized to either manual or robot‐assisted surgery. Participants completed repetitions of a test consisting of three vitreoretinal modules on the Eyesi virtual reality simulator. The primary outcome measure was time to learning curve plateau (minutes) for total test score. The secondary outcome measures were instrument movement (mm), tissue treatment (mm2) and time with instruments inserted (seconds).

Results

There was no significant difference in time to learning curve plateau for robot‐assisted vitreoretinal surgery compared to manual. Robot‐assisted vitreoretinal surgery was associated with less instrument movements (i.e. improved precision), −0.91 standard deviation (SD) units (p < 0.001). Furthermore, robot‐assisted vitreoretinal surgery was associated with less tissue damage when compared to manual surgery, −0.94 SD units (p = 0.002). Lastly, robot‐assisted vitreoretinal surgery was slower than manual surgery, 0.93 SD units (p < 0.001).

Conclusions

There was no significant difference between the lengths of the learning curves for robot‐assisted vitreoretinal surgery compared to manual surgery. Robot‐assisted vitreoretinal surgery was more precise, associated with less tissue damage, and slower.
Applicability of ancestral genotyping in pharmacogenomic research with hormonal contraception
Authors: Lazorwitz Aaron , Aquilante Christina L. , Shortt Jonathan A. , Sheeder Jeanelle , Teal Stephanie , Gignoux Christopher R.
Published: March 2021

To compare etonogestrel pharmacokinetic and pharmacodynamic outcomes by both self‐reported race/ethnicity and genetically determined ancestry among contraceptive implant users. We conducted a secondary analysis of our parent pharmacogenomic study of 350 implant users. We genotyped these reproductive‐aged (18–45 years) women for 88 ancestry‐informative single nucleotide polymorphisms. We then assigned each participant a proportion value for African (AFR), European (EUR), and Indigenous American (AMR) ancestry based on reference population data. We correlated genetic ancestry with self‐reported race/ethnicity and utilized genetic ancestry proportion values as variables for previously performed association analyses with serum etonogestrel concentrations and progestin‐related side effects (e.g., bothersome bleeding and subjective weight gain). We successfully estimated genetically determined ancestry for 332 participants. EUR, AFR, and AMR ancestry were each highly correlated with self‐reported White/non‐Hispanic race (r = 0.64, p = 4.14 × 10−40), Black/African American race (r = 0.88, p = 1.36 × 10−107), and Hispanic/Latina ethnicity (r = 0.68, p = 4.03 × 10−47), respectively. Neither genetically determined ancestry nor self‐reported race/ethnicity were significantly associated with serum etonogestrel concentrations. AFR ancestry and self‐reported Black race had similar associations with reporting monthly periods (odds ratio [OR] 2.18, p = 0.09 vs. OR 2.22, p = 0.02) and having received treatment for bothersome bleeding (OR 5.19, p = 0.005 vs. OR 4.73, p = 2.0 × 10−4). In multivariable logistic regression for subjective weight gain, AMR ancestry dropped out of the model in preference for self‐reported Hispanic/Latina ethnicity. We found no new associations between genetically determined ancestry and contraceptive implant pharmacodynamics/pharmacokinetics. Self‐reported race/ethnicity were strong surrogates for genetically determined ancestry among this population of contraceptive implant users. Our data suggest that self‐reported race/ethnicity, capturing societal and cultural aspects, remain important to the investigation of progestin‐related side effects.
Titratable fixed‐ratio combination of basal insulin plus a glucagon‐like peptide‐1 receptor agonist: A novel, simplified alternative to premix insulin for type 2 diabetes
Authors: Gomez‐Peralta Fernando , Al‐Ozairi Ebaa , Jude Edward B. , Li Xiaoying , Rosenstock Julio
Published: March 2021

Despite novel therapeutic options, many people with type 2 diabetes (T2D) do not achieve their HbA1c targets. Given the progressive nature of T2D, many individuals not controlled with oral therapy will require advancement to injectable therapy using either a glucagon‐like peptide‐1 receptor agonist (GLP‐1 RA), recently recommended as a first option, or traditionally a basal insulin. However, premix insulins remain frequently used, either as initial injectable therapy or as intensification from basal insulin. Premix insulin injections can potentially provide significant glycaemic improvements to basal insulin but at the expense of increased hypoglycaemia and weight gain and the need for multiple daily doses, which may affect treatment adherence. Real‐world evidence suggests that glycaemic control often remains suboptimal with premix insulins. Fixed‐ratio combinations (FRCs) of basal insulin and GLP‐1 RAs provide a novel alternative to premix insulin for therapy intensification. While no direct comparisons between premix insulins and FRCs are available, results from meta‐analyses suggest that FRCs may offer better HbA1c reductions, a lower risk of hypoglycaemia and less weight gain compared with premix insulin in a simplified treatment regimen. A head‐to‐head trial of T2D treatment intensification with premix insulin and a FRC of basal insulin plus a GLP‐1 RA is currently in progress, which should help to clarify the outcomes for each treatment option. This review discusses the unmet needs of people with T2D treated with premix insulin and provides evidence supporting FRCs of basal insulin and GLP‐1 RAs as an alternative treatment option.
Populations of high‐value predators reflect the traits of their prey
Authors: Gutiérrez‐Cánovas Cayetano , Worthington Thomas A. , Jâms Ifan B. , Noble David G. , Perkins Daniel M. , Vaughan Ian P. , Woodward Guy , Ormerod Steve J. , Durance Isabelle
Published: March 2021

The extent to which prey traits combine to influence the abundance of predators is still poorly understood, particularly for mixed predators in sympatry and in aquatic ecosystems. In this study, we characterise prey use and distribution in iconic bird (grey wagtails and Eurasian dippers) and fish species (brown trout and Atlantic salmon) to assess whether prey traits could predict populations of these four riverine predators. Specifically, we hypothesised that: 1) prey key traits would predict predator populations more effectively than 2) diversity of prey traits, 3) the taxonomic abundance or richness of prey (known as traditional or mass‐effect types of biodiversity) or 4) the prevailing environmental conditions. Combined predator population sizes were predicted better by a few key traits – specifically those revealing prey habitat use, size and drifting behaviour – than by prey diversity or prey trait diversity or environmental conditions. Our findings demonstrate that the complex relationships between prey assemblages and multiple predator species can be represented mechanistically when the key prey traits that govern encounter and consumption rates are identified. Given their apparent potential to reveal trophic relationships, and to complement more traditional measures of prey abundance, we advocate further development of trait‐based approaches in predator–prey research.
Assessment of mating competitiveness of sterile Ceratitis capitata in laboratory and field cage tests in northern Iran
Authors: Ahmadi Mehrdad , Osouli Shiva , Abd‐Alla Adly Mohamed Mohamed , Kalantarian Nadia
Published: March 2021

In recent years, damage by Mediterranean fruit fly (medfly) Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) on commercial fruit crops has reached a critical point in Iran. The sterile insect technique is considered the most effective strategy for the area‐wide suppression or eradication of tephritid fruit flies, particularly the medfly. In this study, an area of citrus trees, including 39 field cages in Sari‐Mazandaran province, was used for an experiment to test various irradiation doses and overflowing ratios on male competitiveness‐induced sterility. Treatments 1 and 2 consisted of non‐irradiated females (NF), non‐irradiated males (NM), and irradiated males (IM) which emerged from pupae irradiated with 80 or 100 Gy. The IM:NM:NF ratios per field cage were varied as follows: 0:1:1, 1:0:1, 1:1:1, 3:1:1, 5:1:1, 10:1:1, and 15:1:1. We found that the mating rate of NF copulating with IM was significantly lower than that of NF mated with NM. The numbers of eggs and the percentages of egg hatching were significantly lower in IM × NF than in NM × NF crosses, and no eggs hatched in the 80–130 Gy dose range. The results of Fried's CV (male mating competitiveness value based on egg hatch) ranged from 0.41 to 0.78 at a dose of 80 Gy and from 0.35 to 0.63 at 100 Gy for various mating rates. It can be concluded that IM was fully competitive with NM at the dose range of 80–100 Gy of gamma radiation.
Interacting effects of urea and water addition on soil mineral‐bound phosphorus dynamics in semi‐arid grasslands with different land‐use history
Authors: Wang Ruzhen , Liu Heyong , Sardans Jordi , Feng Xue , Xu Zhuwen , Peñuelas Josep
Published: March 2021

Nitrogen (N) addition and precipitation increment can greatly influence soil phosphorus (P) dynamics, with much emphasis on total and available P, yet little is known about their interactive effects on soil mineral‐bound inorganic P (Pi) fractions under different historical land uses of grasslands and old fields. Thus, we compared (i) plant readily available P, (ii) less available Pi (sum of NH4F‐extractable Pi, NaOH‐Na2CO3‐extractable Pi and NaHCO3‐extracted Pi), (iii) refractory forms of Pi (NH4Ac‐extractable Pi, H2SO4‐extractable Pi and Na3(citrate)‐dithionite‐extractable Pi) and (iv) organic P under the same urea and water treatments in an old‐field grassland with a semi‐arid steppe. Soil total P remained unchanged with 10‐year urea addition in both sites, with lower organic P but higher Pi concentrations in the old field. Urea addition promoted transformation of refractory Pi into less available Pi in both sites, which potentially was related to higher plant productivity and thus enhanced plant P accumulation. Specifically, urea addition increased less available Pi fractions by as much as 42%, but decreased refractory Pi fractions by as much as 24%, for two sites under ambient precipitation. Water addition decreased less available Pi in the steppe under higher urea addition rates, whereas it increased less available and refractory Pi but only in the control plot of the old field. Irrespective of urea and water treatments, the old field had a higher Pi pool, which could replenish plant readily available P in the longer term and be less prone to P‐limitation than the steppe. We conclude that conversion of semi‐arid steppe to farmland causes long‐term increases in the soil Pi pool, possibly by enhancing organic P mineralization and anthropogenic fertilization during cultivation. Urea addition accelerated soil P cycling via promoting refractory Pi, transforming into less available Pi, with the process being strongly mediated by water availability, whereas the projected precipitation increment could decrease less available Pi via promoting plant P uptake and P leaching out of the plant–soil system.

Highlights

Urea addition promoted transformation of refractory Pi into less available Pi fractions.

Water addition counteracted the positive urea effect on NH4F‐Pi in both steppe and old field.

Less responsive organic P suggested that Pi fractions were more essential in soil P cycling.

Water addition decreased NH4F‐Pi in both sites, potentially due to higher plant uptake and leaching.

Conversion of steppe to farmland increased the soil Pi pool by enhancing organic P mineralization.
Photoperiod decelerates the advance of spring phenology of six deciduous tree species under climate warming
Authors: Meng Lin , Zhou Yuyu , Gu Lianhong , Richardson Andrew D. , Peñuelas Josep , Fu Yongshuo , Wang Yeqiao , Asrar Ghasserm R. , De Boeck Hans J. , Mao Jiafu , Zhang Yongguang , Wang Zhuosen
Published: March 2021

Vegetation phenology in spring has substantially advanced under climate warming, consequently shifting the seasonality of ecosystem process and altering biosphere–atmosphere feedbacks. However, whether and to what extent photoperiod (i.e., daylength) affects the phenological advancement is unclear, leading to large uncertainties in projecting future phenological changes. Here we examined the photoperiod effect on spring phenology at a regional scale using in situ observation of six deciduous tree species from the Pan European Phenological Network during 1980–2016. We disentangled the photoperiod effect from the temperature effect (i.e., forcing and chilling) by utilizing the unique topography of the northern Alps of Europe (i.e., varying daylength but uniform temperature distribution across latitudes) and examining phenological changes across latitudes. We found prominent photoperiod‐induced shifts in spring leaf‐out across latitudes (up to 1.7 days per latitudinal degree). Photoperiod regulates spring phenology by delaying early leaf‐out and advancing late leaf‐out caused by temperature variations. Based on these findings, we proposed two phenological models that consider the photoperiod effect through different mechanisms and compared them with a chilling model. We found that photoperiod regulation would slow down the advance in spring leaf‐out under projected climate warming and thus mitigate the increasing frost risk in spring that deciduous forests will face in the future. Our findings identify photoperiod as a critical but understudied factor influencing spring phenology, suggesting that the responses of terrestrial ecosystem processes to climate warming are likely to be overestimated without adequately considering the photoperiod effect.
RNA receptors, TLR3 and TLR7, are potentially associated with SLE clinical features
Authors: Elloumi Nesrine , Fakhfakh Raouia , Abida Olfa , Hachicha Hend , Marzouk Sameh , Fourati Mohamed , bahloul Zouhir , Masmoudi Hatem
Published: March 2021

The influence of intracellular Toll‐like‐receptors (TLR), recognized as nucleic acid sensors, in the immunopathogenesis of systemic lupus erythematosus (SLE) is increasingly explored. Yet, the results of both functional and genetic studies remain conflictual. We evaluated the association between TLR3 and TLR7 genes selected variants and SLE and investigated the possible relationship with clinical and serological parameters. Then, we studied the genetic expression of these receptors, and if the TLR7 gene evades X chromosome inactivation (XCI). Our study covers 106 cases and 200 controls, genotyped using a polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) technique. TLR3 and TLR7 expression level was assessed by qPCR carried, respectively, on renal tissues and PBMC, and methylation status was evaluated by methylation‐specific PCR. Results were statistically analysed using Shesis software, χ2, and Mann–Whitney test. Significant associations with SLE susceptibility were found for the TLR3 rs3775291, rs5743305 and rs3775294 polymorphisms. Further subgroup analysis, TLR3 rs3775291 and rs3775294 polymorphisms were significantly associated with lupus nephritis (LN) and even correlate with the presence of auto‐antibodies binding RNA molecules. SLE and LN were more common in men with rs3853839‐G variant within TLR7 gene versus those carrying the C allele. Moreover, the role of the G allele in the TLR7 expression up‐regulation was confirmed. However, gene expression analysis showed no significant differences in TLR3 and TLR7 mRNA levels between LN patient biopsies and healthy tissues (p > .05). When comparing patients and controls, no statistical difference was observed in XCI pattern. Otherwise, notable associations were raised between TLR3 and TLR7 gene variants and clinical and serological lupus features pointing towards the role of genetic background in the physiopathogenesis of the disease.
Limitarianism: Pattern, Principle, or Presumption?
Authors: Timmer Dick
Published: March 2021

In this article, I assess the prospects for the limitarian thesis that someone has too much wealth if they exceed a specific wealth threshold. Limitarianism claims that there are good political and/or ethical reasons to prevent people from having such ‘surplus wealth’, for example, because it has no moral value for the holder or because allowing people to have surplus wealth has less moral value than redistributing it. Drawing on recent literature on distributive justice, I defend two types of limitarian principles of justice. First, limitarian midlevel principles draw on the limitarian thesis to specify normative commitments for guiding institutional design and individual actions. Second, the limitarian presumption draws on that thesis to specify what a just allocation of wealth requires under epistemic constraints. Such a presumption says that without substantive reasons to the contrary, we should regard a distribution as unjust if some people’s wealth exceeds the limitarian threshold. Furthermore, I will argue that we must reject a possible but implausible interpretation of limitarianism as an ideal distributive pattern. Yet both as a midlevel principle and as a presumption, limitarianism can play an important role in theorizing about justice in the real world.
Impact of age on catheter ablation of premature ventricular contractions
Authors: Badertscher Patrick , John Leah , Payne Joshua , Bainey Adam , Ishida Yuji , Field Michael E. , Winterfield Jeffrey R , Gold Michael R
Published: March 2021

Introduction

Catheter ablation (CA) of frequent premature ventricular contractions (PVC) is increasingly performed in older patients as the population ages. The aim of this study was to assess the impact of age on procedural characteristics, safety and efficacy on PVC ablations.

Methods

Consecutive patients with symptomatic PVCs undergoing CA between 2015 and 2020 were evaluated. Acute ablation success was defined as the elimination of PVCs at the end of the procedure. Sustained success was defined as an elimination of symptoms, and ≥80% reduction of PVC burden determined by Holter‐electrocardiogram during long‐term follow. Patients were sub‐grouped based on age (<65 vs. ≥65 years).

Results

A total of 114 patients were enrolled (median age 64 years, 71% males) and followed up for a median duration of 228 days. Baseline and procedural data were similar in both age groups. A left‐sided origin of PVCs was more frequently observed in the elderly patient group compared to younger patients (83% vs. 67%; p = .04). The median procedure time was significantly shorter in elderly patients (160 vs. 193 min; p = .02). The rates of both acute (86% vs. 92%; p = .32) and sustained success (70% vs. 71%; p = .90) were similar between groups. Complications rates (3.7%) did not differ between the two groups.

Conclusion

In a large series of patients with a variety of underlying arrhythmia substrates, similar rates of acute procedural success, complications, and ventricular arrhythmia‐free‐survival were observed after CA of PVCs. Older age alone should not be a reason to withhold CA of PVCs.
Safety and complications of catheter ablation for atrial fibrillation: Predictors of complications from an updated analysis the National Inpatient Database
Authors: Wu Lingling , Narasimhan Bharat , Ho Kam S. , Zheng Yingying , Shah Arti N. , Kantharia Bharat K.
Published: March 2021

Background

Catheter ablation is increasingly employed in the management of atrial fibrillation (AF). Data regarding safety of ablation of AF is largely derived from controlled clinical trials.

Objectives

The aim of this study was to analyze safety and complications of AF ablation performed in a “real world” setting outside of clinical trials, and obtain insights on predictors of complications.

Methods

We utilized the National Inpatient Sample database, to identify all patients who underwent AF ablations between 2015 and 2017 using International Classification of Disease—Tenth revision codes. Complications were defined as per the Agency for Health Care Research and Quality Guidelines. Statistical tests including multivariate logistic regression were performed to determine predictors of complications.

Results

Among 14,875 cases of AF ablation between 2015 and 2017, a total of 1884 complications were identified among 1080 (7.2%) patients. Patients with complications were likely to be older and female with a higher burden of comorbidities. A 27% increase in complications was observed from 2015 to 2017, driven by an increase in pericardial complications. Multivariate regression analysis revealed that pulmonary hypertension (adjusted odds ratio [aOR]: 1.99, p = .041) and chronic kidney disease (CKD; aOR: 1.67, p = .024), were independent predictors of complications. Centers with higher procedural volumes were associated with lower complication rates.

Conclusions

Complication rates related to AF ablations remain substantially high. Presence of pulmonary hypertension and CKD are predictive of higher procedural complications. Furthermore, hospital procedure volume is an important factor that correlates with complication rates.
Prospective study: Aldehyde dehydrogenase 2 gene is associated with cardio‐cerebrovascular complications in type 2 diabetes patients
Authors: He Qingfang , Pan Jin , Wang Lixin , Fang Yujia , Hu Ruying
Published: March 2021

Aims/Introduction

Most studies have shown that aldehyde dehydrogenase 2 (ALDH2) mutations were associated with cardio‐cerebrovascular complications of diabetes based on cross‐sectional investigations, but few studies based on cohorts were carried out. The aim of this study was to explore the correlation between the ALDH2 gene and the occurrence of and death from cardio‐cerebrovascular complications in type 2 diabetes patients through a prospective cohort study.

Materials and Methods

According to a community‐based and disease‐based prospective cohort study design, a baseline cohort of 10,339 persons with type 2 diabetes was established in 2016, and the occurrence of and death from cardio‐cerebrovascular complications were followed up until December 2018. A total of 2,500 diabetes patients without cardio‐cerebrovascular complications were randomly selected from the baseline cohort to detect the rs671 polymorphism of the ALDH2 gene. Cox regression analysis was carried out on the effect of different ALDH2 rs671 single‐nucleotide polymorphisms on the risk and survival time of cardio‐cerebrovascular complications among diabetes patients.

Results

There were 215 cardio‐cerebrovascular complications, including 10 deaths, that occurred in the 2,500 diabetes patients during the follow‐up period. Cox regression analysis showed that rs671 GA/AA genotype, sex (male), poor control of high‐density lipoprotein cholesterol, low‐density lipoprotein cholesterol, blood pressure and glycated were risk factors, whereas drinking alcohol was a protective factor for cardio‐cerebrovascular complications (P < 0.05). After adjusting for age and sex, the risk of the rs671 GA/AA genotype was 1.314‐fold (95% confidence interval 1.000–1.727) that of the GG genotype.

Conclusion

The G‐A mutation of ALDH2 rs671 is a risk factor for the occurrence of and death from cardio‐cerebrovascular complications in type 2 diabetes patients. Further studies with larger cohorts and longer follow up will be necessary to reveal a consensus.
Public transport, noise complaints, and housing: Evidence from sentiment analysis in Singapore
Authors: Fan Yi , Teo Ho Pin , Wan Wayne X.
Published: March 2021

This paper investigates the effect of a new bus route on noise complaints of residents and the influence of noise on housing price. To overcome the challenge of mapping noise data with subjective emotion, we use a novel data source—text‐based noise complaint records from residents in a town in Singapore—and apply natural language processing tools to conduct sentiment analysis. To address the endogeneity concern regarding the bus route, we use a hypothetical least cost path as an instrument for the existing bus route. We find that living closer to the bus route for every 100 m increases noise complaints by around 10 percentage points, and the effect is more severe on medium floor levels (5th–8th floors) and near bus stops (within 100 m). We further link noise with housing price and discover a price reduction of 3% with a 1‐scale‐point increase in noise complaints. This implies that bus noise offsets 17.8% of the benefit from convenience, which sheds light on the importance of noise insulation in transit‐oriented developments.
Morphological and genetic analyses of Ostreopsis (Dinophyceae, Gonyaulacales, Ostreopsidaceae) species from Vietnamese waters with a re‐description of the type species, O. siamensis
Authors: Nguyen‐Ngoc Lam , Doan‐Nhu Hai , Larsen Jacob , Phan‐Tan Luom , Nguyen Xuan‐Vy , Lundholm Nina , Van Chu Thuoc , Huynh‐Thi Duyen Ngoc
Published: March 2021

Identification of species of the dinoflagellate genus Ostreopsis is difficult because several species have been poorly described, others misidentified in the literature, and the type species, O. siamensis, has not been described by contemporary taxonomic methods. In the present study, it is argued that Ostreopsis sp. 6 as described by previous authors is similar to the type species, and we offer an emended description of O. siamensis by LM, SEM, and molecular analyses of nuclear LSU and ITS rDNA based on material collected a few hundred kilometers from the type locality in the Gulf of Thailand and along the Vietnamese east coast. Ostreopsis siamensis is genetically different from the species reported as O. cf. siamensis in the literature and the latter should be described as a separate species. It is also concluded that with the poor knowledge of the morphological variability of many species of Ostreopsis, O. siamensis may not be distinguished from other similar‐sized species by its morphological features, and hence molecular data are needed for reliable identification. The species Ostreopsis lenticularis and Ostreopsis cf. ovata were also found and described.
But They Told Us It Was Safe! Carbon Dioxide Removal, Fracking, and Ripple Effects in Risk Perceptions
Authors: Cox Emily , Pidgeon Nick , Spence Elspeth
Published: March 2021

Reaching net‐zero for global greenhouse gas emissions by the year 2050 will require a portfolio of new technologies and approaches, potentially requiring direct removal and sequestration of atmospheric carbon dioxide using negative emissions technologies (NETs). Since energy and climate systems are fundamentally interconnected it is important that we understand the impacts of policy decisions and their associated controversies in other related technologies and sectors. Using a secondary analysis of data from a series of deliberative workshops conducted with lay publics in the United Kingdom, we suggest that perceptions of CO2 removal technologies were negatively impacted by risk perceptions and recent policy decisions surrounding shale gas and fracking. Using the social amplification of risk framework, we argue that heightened risk perceptions have extended via “ripple effects” across these technologies. Participants’ attitudes were underpinned by deeper misgivings regarding the actions and motives of experts and policymakers; a pervasive discourse of “but they told us it was safe” regarding fracking negatively affected people's trust in assurances of the safety and efficacy of CO2 removal. This has the potential to undermine attempts to build societal agreement around future deployment of CO2 removal technologies.
A novel B*07 variant allele, B*07:416, identified by next‐generation sequencing
Authors: Tang Mei San , Duffy Brian F. , Jennemann Jo‐Ellen , Parikh Bijal A. , Liu Chang
Published: March 2021

HLA‐B*07:416 differs from HLA‐B*07:02 by a missense mutation at codon 92 of the cDNA sequence.
Identification of transcription factors controlling cell wall invertase gene expression for reproductive development via bioinformatic and transgenic analyses
Authors: Li Jun , Foster Ryan , Ma Si , Liao Sheng‐Jin , Bliss Samuel , Kartika Dewi , Wang Lu , Wu Limin , Eamens Andrew L. , Ruan Yong‐Ling
Published: March 2021

Cell wall invertase (CWIN) hydrolyses sucrose into glucose and fructose in the extracellular matrix and plays crucial roles in assimilate partitioning and sugar signalling. However, the molecular regulators controlling CWIN gene transcription remain unknown. As the first step to address this issue, we performed bioinformatic and transgenic studies, which identified a cohort of transcription factors (TFs) modulating CWIN gene expression in Arabidopsis thaliana. Comprehensive bioinformatic analyses identified 18 TFs as putative regulators of the expression of AtCWIN2 and AtCWIN4 that are predominantly expressed in Arabidopsis reproductive organs. Among them, MYB21, ARF6, ARF8, AP3 and CRC were subsequently shown to be the most likely regulators of CWIN gene expression based on molecular characterization of the respective mutant of each candidate TF. More specifically, the obtained data indicate that ARF6, ARF8 and MYB21 regulate CWIN2 expression in the anthers and CWIN4 in nectaries, anthers and petals, whereas AP3 and CRC were determined primarily to regulate the transcriptional activity of CWIN4. TF‐promoter interaction assays demonstrated that ARF6 and ARF8 directly control CWIN2 and CWIN4 transcription with AP3 activating CWIN4. The involvement of ARF8 in regulating CWIN4 expression was further supported by the finding that enhanced CWIN4 expression partially recovered the short silique phenotype displayed by the arf8‐3 mutant. The identification of the five TFs regulating CWIN expression serves as a launching pad for future studies to dissect the upstream molecular network underpinning the transcription of CWINs and provides a new avenue, potentially, to engineer assimilate allocation and reproductive development for improving seed yield.
The impact of health‐related quality of life and depressive symptoms on blood donor career—Results from the Danish blood donor study
Authors: Didriksen Maria , Thørner Lise W. , Larsen Margit A. H. , Sørensen Erik , Burgdorf Kristoffer , Mikkelsen Susan , Rostgaard Klaus , Banasik Karina , Pedersen Ole B. , Erikstrup Christian , Nielsen Kaspar R. , Bruun Mie T. , Hjalgrim Henrik , Ullum Henrik
Published: March 2021

Background

Blood donors report better health‐related quality of life (HRQL) than non‐donors. Likewise, donors reporting good health are less likely to stop donating and have a higher donation frequency. This is evidence of the healthy donor effect (HDE). This study is the first to investigate the impact of HRQL and depressive symptoms on subsequent donor career.

Study Design and Methods

Prospective cohort study includes 102,065 participants from the Danish Blood Donor Study applying the 12‐item short‐form health survey (SF‐12) measuring a mental (MCS) and a physical component score (PCS) and the Major Depression Inventory (MDI). Poisson and Cox regression models were used to assess the effect of SF‐12 and MDI scores on donation frequency and donor cessation. Higher MCS/PCS scores indicate good HRQL, while higher MDI score indicates higher experience of depressive symptoms.

Results

For both sexes, MCS was positively correlated with donation frequency for up to 5 years, and similarly for PCS among women. A negative correlation between MDI score and donation frequency in the year following assessment was observed only among men. No correlation was observed among women. An increase in both MCS and PCS was associated with a lower risk of donation cessation in both sexes, while an increase in MDI score was only associated with an increased risk of donation cessation in men.

Conclusion

MCS, PCS, and MDI score affect donor career. Thus, adjusting for donation frequency may reduce HDE‐bias in donor health research. However, because of the small effect sizes, other ways of quantifying HDE may be beneficial.
Prevalence and incidence of injuries among female cricket players: a systematic review protocol
Authors: Jacobs Jolandi , Olivier Benita , Dawood Muhammad , Panagodage Perera Nirmala Kanthi
Published: March 2021

Objective:

The objective of this systematic review is to describe the incidence and prevalence of injuries in female cricket players participating in recreational-, school-, club-, and elite-level cricket.

Introduction:

Recent investments in women's cricket, stand-alone tournaments, and increased visibility through new broadcasting milestones has increased participation in many countries. With increased participation of women in cricket comes increased risk of injury. Epidemiological data are needed to underpin evidence-based injury-prevention strategies. No systematic review or meta-analysis of injuries is currently available to provide a comprehensive overview of synthesized findings to make the evidence accessible.

Inclusion criteria:

Studies on female cricket players of all ages and participating in all levels of cricket will be included. Studies that contain data on only male cricket players will be excluded. Studies where data from female cricket players can be distinguished from male players will be included. Injuries sustained when playing cricket, that are self-reported or diagnosed by a health care professional will be included. Definitions of injury including, but not limited to, medical-attention injuries, general time-loss injuries, or player-reported injuries will be considered.

Methods:

MEDLINE, SPORTDiscus, Physiotherapy Evidence Database (PEDro), EBSCO MasterFILE Premier, EBSCO CINAHL Complete, ProQuest Health and Medical Complete, Scopus, and ScienceDirect will be systematically searched from inception to the present. Cochrane Central Register of Controlled Trials and ClincalTrials.gov will be searched as well as gray literature databases. Retrieval of full-text studies, assessment of methodological quality, and data extraction will be performed independently by two reviewers. If possible, meta-analyses will be performed.

Systematic review registration number:

PROSPERO CRD42020166052
Bearing Pressures and Cracks: Bearing Pressures Through a Slightly Waved Surface or Through a Nearly Flat Part of a Cylinder, and Related Problems of Cracks
Authors: Westergaard H. M.
Published: March 2021

The task is undertaken of determining the bearing pressures, and the stresses and deformations created by them, in some cases that differ from those considered by Hertz in his classical study of contact. Thus two solids are examined which, before loading, are in contact along a row of evenly spaced lines in a horizontal plane, as indicated in Fig. 1(a). Between these lines the surfaces have a separation defined by a nearly flat cosine wave. A uniform pressure on top of the upper solid creates contact over an area consisting of a row of strips, reduces the separation of the solids between the strips, as suggested in Fig. 1(b), and creates contact pressures distributed as indicated in Fig. 1(c), with vertical rises in the diagram of pressure at the edges of the strips. At a greater load the width of the strip becomes equal to the wave length, and the contact is complete. At still greater loads the stresses increase as if the two solids were one. The procedure by which this problem is solved is demonstrated first by showing its easy application to some well-known cases, especially Hertz’s problem of circular cylinders in contact.

Further applications are to a noncircular cylinder resting on a solid with a flat top, with an initial separation of the surfaces varying as the fourth power of the distance from the initial line of contact; to partial contact of two surfaces which are initially plane, except that one of them has a ridge or several parallel ridges; and to some related problems in which two parts of the same body are partially separated by the forming of one or more cracks.
A Theory of Flexure for Beams With Nonparallel Extreme Fibers
Authors: Osgood William R.
Published: March 2021

A theory of flexure for beams with nonparallel extreme fibers is presented. The theory is shown to reduce to the ordinary theory of flexure as the angle between the extreme fibers approaches zero. Maximum fiber stresses computed by the theory and by the ordinary theory for a plate girder with nonparallel flanges show that for angles between the flanges up to twenty degrees the ordinary theory can never be in error more than about five per cent, but for larger angles the error in general increases rapidly with the angle. Finally an example is given of the application of the theory as an approximation to a beam with curved extreme fibers. In this case the theory was confirmed by the results of tests.
Some Applications of Photoelasticity in Turbine-Generator Design
Authors: Hetényi M.
Published: March 2021

This paper deals with three particular problems in turbine-generator design, namely (a) stress concentrations in transverse grooves of two-pole generator rotors, (b) centrifugal stresses in rotors, and (c) stress concentrations in T-heads (bolts and blade fastenings). The connection between these problems is only their mutual sphere of application and the fact that in each case the solution has been obtained by photoelasticity. The problems have been investigated as two-dimensional ones, the first and third being analyzed by the standard photoelastic technique, while in the second problem the fundamentally three-dimensional method of “freezing” the stresses in bakelite samples was applied.
Rubber Springs—Shear Loading
Authors: Downie Smith J. F.
Published: March 2021

The designer in industry should be in a position to predetermine by calculation the size and hardness of, and the deflection to be expected from, a rubber spring which is to serve a special purpose. Unfortunately the literature contains little which would be of help; and it is the author’s intention in this paper to supply such information for rubber springs loaded in shear. Most of the designs ordinarily encountered in practice have been considered.

The agreement of theory and experiment is shown in all cases where data are available.

A chart is given which enables anyone to determine immediately the shear angle expected from a plane shear mounting of any size and rubber hardness within the limits ordinarily used for springs.
A Convenient Electrical Micrometer and Its Use in Mechanical Measurements
Authors: Gunn Ross
Published: March 2021

A simple electrical micrometer of great mechanical and electrical stability has been developed. The electrical-current output from the micrometer is accurately proportional to the impressed mechanical displacement. The least count of typical micrometers using portable micro-ammeters as indicators and employing no amplification is 5/1,000,000 in. Zero drift, hysteresis, temperature, and pressure variations have been reduced to less than 1 per cent. Special circuits are described which permit the indication of the sums, differences, ratios, or products of mechanical displacements and hence are useful in many mechanical measurements. The micrometer is also convenient for zero and low-frequency vibration studies.
A Photoelastic Study of Stresses in Rotating Disks
Authors: Newton R. E.
Published: March 2021

The recent experiments of Hetényi and others in developing a technique for “freezing” stresses in bakelite and other photoelastic plastics have broadened tremendously the scope of the photoelastic method of stress analysis. In addition to making possible the solution of three-dimensional problems, the new technique offers itself as a powerful tool in solving problems in which it is inconvenient to study the fringe pattern while the model is actually under load. Problems of centrifugal stresses in constant-speed rotors fall in this class and are readily handled by the stress-freezing method. It is the purpose of this paper to discuss the application of the technique to the determination of the stresses in rotating disks of uniform thickness having symmetrically placed noncentral holes, as shown in Fig. 1 (1, 2).
Improvement of Displacement Efficiency in Heavy Oil Reservoirs With Enzyme
Authors: Shi Yu , Ding Yanan , Feng Qianghan , Yang Daoyong
Published: March 2021

In this study, a systematical technique has been developed to experimentally and numerically evaluate the displacement efficiency in heavy oil reservoirs with enzyme under different conditions. First, dynamic interfacial tensions (IFTs) between enzyme solution and heavy oil are measured with a pendant-drop tensiometer, while effects of pressure, temperature, enzyme concentration, and contact time of enzyme and heavy oil on equilibrium IFT were systematically examined and analyzed. After waterflooding, enzyme flooding was carried out in sandpacks to evaluate its potential to enhance heavy oil recovery at high water-cut stage. Numerical simulation was then performed to identify the underlying mechanisms accounting for the enzyme flooding performance. Subsequently, a total of 18 scenarios were designed to simulate and examine effects of the injection modes and temperature on oil recovery. Except for pressure, temperature, enzyme concentration, and contact time are found to impose a great impact on the equilibrium IFTs, i.e., a high temperature, a high enzyme concentration, and a long contact time reduce the equilibrium IFTs. All three enzyme flooding tests with different enzyme concentrations show the superior recovery performance in comparison to that of pure waterflooding. In addition to the IFT reduction, modification of relative permeability curves is found to be the main reason responsible for further mobilizing the residual heavy oil. A large slug size of enzyme solution usually leads to a high recovery factor, although its incremental oil production is gradually decreased. In addition, temperature is found to have a great effect on the recovery factor of enzyme flooding likely owing to reduction of both oil viscosity and IFT.
An Improved Method for Extracting Photovoltaic Module I–V Characteristic Curve Using Hybrid Learning Machine System
Authors: Khatib Tamer , Direya Rezeq , Said Asmaa
Published: March 2021

This paper provides an improved method for predicting the I–V curve of the photovoltaic module using a hybrid machine learning system. The proposed method is based on a random forest algorithm and a cascade forward neural network. A random forest algorithm is used to predict a specific factor that is subsequently used as an input for the cascade neural network to remove the correlation between voltage and current. Then, the actual current is predicted using the cascade neural network. This procedure assures the ability of the proposed model to extract the I–V curve of any photovoltaic module regardless of its rating or type. A dataset that contains values for air temperature, solar radiation, voltage, and current of two polycrystalline photovoltaic modules is used in the training process of the proposed algorithm. The hybrid model has general inputs such as ambient temperature, solar radiation, and data from the photovoltaic module datasheet (Voc and Isc). The proposed model is trained, tested, and validated by 86% of the data. Meanwhile, 14% of the data are used for testing. Thus, the proposed model is tested using unknown data so as to avoid overfitting. Results show that the proposed model is very accurate in predicting I–V curves based on three types of errors which are mean absolute percentage error (0.68%), mean bias error (0.0191 A), and root-mean-squared error (0.04458 A). This hybrid model can be used to obtain the I–V curves for several types of photovoltaic modules.