bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional traits and phenotypic plasticity modulate species coexistence across contrasting environments
Authors: Perez-Ramos Ignacio Manuel , Matias Luis , Gomez Aparicio Lorena , Godoy Oscar
Published: February 2019

Functional traits are expected to modulate plant competitive dynamics. However, how traits and their plasticity in response to contrasting environments connect with the mechanisms determining species coexistence remains poorly understood. Here, we coupled field experiments under two contrasted climatic conditions to a plant population model describing competitive dynamics between 10 annual plant species in order to evaluate the associations of niche and fitness differences with 19 functional traits covering physiological, morphological and reproductive characteristics. We found a rich diversity of univariate and multidimensional relationships, in which outstand the primary role of traits related to water- and light-use-efficiency in modulating the determinants of competitive outcomes. Importantly, such traits and their plasticity promoted species coexistence across climatic conditions by enhancing stabilizing niche differences and by generating competitive trade-offs between species. Our study represents a significant advance showing how leading dimensions of plant form and function connect to the mechanisms determining the maintenance of biodiversity.
Toll-like receptor 2 stimulation augments esophageal epithelial barrier integrity
Authors: Ruffner Melanie A. , Song Li , Maurer Kelly , Shi Lihua , Carroll Margaret C. , Wang Joshua X. , Muir Amanda B. , Spergel Jonathan M. , Sullivan Kathleen E.
Published: February 2019

Background

A key concept of the hygiene hypothesis is that the microbiome modulates both epithelial barrier integrity as well as host immune responses. Defective expression of tight junction complex proteins alters this homeostatic process, and plays a role in atopic disorders including eosinophilic esophagitis. We tested the hypothesis that Toll-like receptor 2 (TLR2) stimulation improves esophageal barrier function in a cell-intrinsic manner by upregulation of TJ-protein expression using an in vitro model of human epithelium.

Methods

Pattern recognition receptor expression was assessed in esophageal epithelial cells from patients with EoE and non-EoE control patients. Functional consequences of TLR2 stimulation were investigated using human esophageal EPC2-hTERT cells in the three-dimensional air-liquid interface culture (ALI) model to evaluate transepithelial electrical resistance (TEER) and FITC-Dextran permeability. Characterization of TLR2-stimulated ALI cultures was performed by histology, immunohistochemistry, western blotting and chromatin immunoprecipitation.

Results

TLR2 stimulation increased TEER (1.28 to 1.31-fold) and decreased paracellular permeability to FITC-Dextran. Notably, TLR2 stimulation-induced increases in TEER were abolished by treatment with anti-TLR2 blocking antibody. Tight junction complex proteins claudin 1 and zonula occludens 1 were increased following TLR2 stimulation, and chromatin immunoprecipitation analysis demonstrated significant increase in histone 4 acetyl binding at the CLDN1 enhancer and promoter following zymosan treatment, implying the occurrence of durable chromatin changes in the esophageal epithelium.

Conclusions

Our findings reveal that the TLR2 pathway may play a regulatory role as a mechanism that maintains epithelial barrier homeostasis in the esophagus.
Dual role of protease activated receptor 4 in acute kidney injury: contributing to renal injury and inflammation, while maintaining the renal filtration barrier upon acute renal ischemia reperfusion injury
Authors: Jansen Marcel. P. B. , Claessen Nike , Larsen Per W.B. , Butter Loes M. , Florquin Sandrine , Roelofs Joris J.T.H.
Published: February 2019

Ischemia reperfusion (I/R) injury triggers the activation of coagulation and inflammation processes involved in the pathophysiology of acute kidney injury (AKI). Coagulation proteases upregulated upon renal I/R injury activate protease activated receptors (PARs), which form an important molecular link between inflammation and coagulation. PAR4 is the major thrombin receptor on mouse platelets, and the only PAR that is expressed on both human and murine platelets. In addition, PAR4 is expressed on other cells including podocytes. We here sought to determine the contribution of PAR4 in the host response to renal I/R injury. Hence, we subjected PAR4 knockout and wild-type mice to renal I/R injury. PAR4 knockout mice exhibited an increased tolerance to renal tubular necrosis and showed a decreased neutrophil influx in response to renal I/R, independent from platelet PAR4. On the other hand, PAR4 deficiency resulted in albumin cast formation in peritubular capillaries and showed a tendency towards albuminuria. Transmission Electron Microscopy revealed an increase in podocyte foot process effacement. Our findings suggest that PAR4 contributes to renal injury likely through facilitating neutrophil migration, independent from platelet PAR4. In addition, PAR4 fulfils an important function in the maintenance of podocyte integrity following renal I/R insult. Subsequently, loss of PAR4 results in albuminuria.
Cataract among elderly in Sri Lanka
Authors: Nilanga Nishad A.A. , Hewage S.A. , Arulmoly K. , Amaratunge M.S. , de Silva J , Kasturiratne KTAA , Abeysundara PK , Wickramasinghe AR
Published: February 2019

Out of 39 billion people who are blind around the world, 20 billion (51.3%) is due to cataract, which is preventable. This study intended to assess the prevalence and factors associated with cataract among elderly in a divisional secretariat area in Sri Lanka. This community based cross sectional study assessed randomly selected470 adults over 60 years of age. Diagnosis of cataract was made by a slit lamp examination by medical officers, and classified according to Oxford Lens Opacity Classification system (LOCS III). Majority was between 60-69 age groups and 71% was females. The prevalence of cataract was estimated to be 80.6% including operated eye and 73.6% excluding the operated eye, with a female preponderance in lower age categories. Commonest type of cataract was the nuclear type (n=422; 44.9%), with a majority in grade 2 (218; 23.2%). The prevalence of cataract surgery in the diseased population was as low as 7%. Cataract leading to blindness is very prevalent among adults over 60 years of age in the studied area. Females tend to develop the disease at an early age than males. These findings warrant screening programme for elderly at community level, targeting females at a younger age than males. Future studies are recommended to assess the coverage and barriers for cataract surgeries at national level, which would be immensely useful in planning and improving health services.
Complete Chloroplast Genome of Castanopsis sclerophylla (Lindl.) Schott: Genome Structures, Comparative and Phylogenetic Analysis
Authors: Ye Xuemin , Hu Dongnan , Guo Yangping , Sun Rongxi
Published: February 2019

Castanopsis sclerophylla (Lindl.) Schott is an important species of evergreen broad-leaved forest in subtropical area and has important ecological and economic value. However, there are little studies on its chloroplast genome. In this study, the complete chloroplast genome sequences of C. sclerophylla was reported based on the Illumina Hiseq 2500 platform. The complete chloroplast genome of C. sclerophylla was 160,497bp, including a pair of inverted repeated (IRs) regions (25,675bp) that were separated by a large single copy (LSC) region of 90,255bp, and a small single copy (SSC) region of 18,892bp. The overall GC content of chloroplast genome was 36.82%. A total of 131 genes were found, of these 111 genes were unique and annotated, including 79 protein-coding genes, 27 transfer RNA genes (tRNAs), and four ribosomal RNA genes (rRNAs). Twenty-one genes were found to be duplicated in the IR regions. Comparative analysis indicated that IR contraction might be the reason for the relatively smaller chloroplast genome size of C. sclerophylla compared with other three congeneric species. Sequence analysis detected that the LSC and SSC regions were more divergent than the IR regions within the Castanopsis, furthermore, a higher divergence was found in non-coding regions than in coding regions. The maximum likelihood (ML) phylogenetic analysis showed that these four species of the genus Castanopsis formed a monophyletic clade and that C. sclerophylla is closely related to Castanopsis hainanensis with strong bootstrap values. These results not only provide basic knowledge about characteristics of C. sclerophylla and also enhance our understanding of Castanopsis species evolution within the Fagaceae family. Meanwhile, these findings will contribute to the exploration, utilization and conservation genetics of C. sclerophylla.
CG dinucleotides enhance promoter activity independent of DNA methylation
Authors: Hartl Dominik , Krebs Arnaud R. , Grand Ralph S. , Baubec Tuncay , Isbel Luke , Wirbelauer Christiane , Burger Lukas , Schübeler Dirk
Published: February 2019

Most mammalian RNA polymerase II initiation events occur at CpG islands, which are rich in CpGs and devoid of DNA methylation. Despite their relevance for gene regulation, it is unknown to what extent the CpG dinucleotide itself actually contributes to promoter activity. To address this question, we determined the transcriptional activity of a large number of chromosomally integrated promoter constructs and monitored binding of transcription factors assumed to play a role in CpG island activity. This revealed that CpG density significantly improves motif-based prediction of transcription factor binding. Our experiments also show that high CpG density alone is insufficient for transcriptional activity, yet results in increased transcriptional output when combined with particular transcription factor motifs. However, this CpG contribution to promoter activity is independent of DNA methyltransferase activity. Together, this refines our understanding of mammalian promoter regulation as it shows that high CpG density within CpG islands directly contributes to an environment permissive for full transcriptional activity.
Language skills in an ethnically segmented labour market: Estonia 1989–2012
Authors: Bormann Sven-Kristjan , Ridala Svetlana , Toomet Ott-Siim
Published: February 2019

Purpose

The purpose of this paper is to analyse the relationship between skills in the Estonian, Russian and English language, and labour market outcomes in Estonia, a linguistically divided country.

Design/methodology/approach

The authors use the Estonian Labour Force Surveys 1992–2012. The authors rely on multivariate linear regression models to document the relationship between language skills and labour market outcomes.

Findings

Estonian language knowledge (for ethnic Russians) are important determinants of unemployment. Wage, in contrary, is closely related to English skills. Ethnic Russian men do not earn any premium from speaking Estonian, while women, fluent in Estonian earn approximately 10 per cent more. For ethnic Estonians, Russian fluency is associated with a similar income gain.

Research limitations/implications

Due to the observational nature of the data, the effects reported in this study are not causal effects. As a second limitation, the self-reported language skills data may be imprecise and hence the effects the authors report may be too small.

Practical implications

The results stress the role of workplace segregation, both along gender and ethnic lines, in determining the individual labour market experience.

Originality/value

The authors provide a comprehensive overview of the effects of language skills in a rapidly developing labour market in a linguistically divided economy. The authors analyse several languages with different legal status and document long-term trends in the effects.
Does it pay to study abroad? Evidence from Poland
Authors: Liwiński Jacek
Published: February 2019

Purpose

The purpose of this paper is to identify the impact of international student mobility (ISM) on the first wages of tertiary education graduates in Poland.

Design/methodology/approach

The author uses data from the nationwide tracer survey of Polish graduates (2007 Graduate Tracer Study) and regresses the hourly net wage rate of salaried workers in their first job after graduating from a higher education institution on a rich set of individual characteristics. In order to reduce the bias due to selection to ISM, the author includes a set of variables representing abilities and skills, characteristics of studies, and international experience as control variables. The author addresses the possible selection to employment bias by using the Heckman correction.

Findings

After controlling for observed heterogeneity, the author finds that Polish graduates who studied abroad for at least one month earn on average 22 per cent more in their first job than those who studied in Poland only. However, the author also finds that this wage premium is explained by international economic migration after graduation. Studying abroad brings a wage premium only if it is followed by working abroad. Those who perform their first job in Poland do not obtain any wage premium from ISM.

Originality/value

The main contribution of the paper is that it identifies international economic migration after graduation as another mechanism explaining why those who studied abroad earn more.
Workplace internet leisure and employees’ productivity
Authors: Mohammad Jihad , Quoquab Farzana , Halimah Siti , Thurasamy Ramayah
Published: February 2019

Purpose

There is an on-going debate about the role of workplace internet leisure (WIL) and whether it is a vice or virtue. Considering this, the purpose of this paper is to examine the effect of WIL on workplace outcome variables such as employee satisfaction (ES) and employee productivity in the Malaysian context.

Design/methodology/approach

Data were collected using a self-administered questionnaire that yielded 282 responses. Partial least square technique using SmartPLS-3 was used to test the study hypotheses.

Findings

Findings reveal that workplace WIL, workplace WIL policy and workplace autonomy orientation (WAO) affect employees’ satisfaction. Additionally, the mediating role of ES was found to be significant.

Practical implications

The findings of this study are valuable for both managers and policy makers. These results can benefit the managers of conventional banks in Malaysia to decide how to enhance employees’ satisfaction and productivity by focusing on the key drivers such as WIL, workplace internet leisure policy (WILP) and WAO.

Originality/value

This is a pioneering study which suggests that moderate use of WIL can have a positive and significant effect on workplace outcome variables. Moreover, this study theorised ES as a mediating variable; this helps to explain how organisations can transform workplace resources in term of internet leisure, WILP and WAO into high productivity by elevating employees’ satisfaction.
Do predictors of mental health differ between home and international students studying in the UK?
Authors: Jones Catrin Pedder , Lodder Annemarie , Papadopoulos Chris
Published: February 2019

Purpose

Previous research has found that international students can experience poor mental health, low levels of life satisfaction, self-esteem and high levels of loneliness when studying in a foreign country. No study has directly compared these between international and home students studying in the UK. The paper aims to discuss these issues.

Design/methodology/approach

A total of 247 students completed an online survey at the University of Bedfordshire.

Findings

The hypothesis that international students experience higher loneliness, lower self-esteem, lower life satisfaction and poorer general mental health than home students was rejected. Home students had significantly lower self-esteem, life satisfaction and general mental health scores. Black ethnicity and home student status significantly predicted general mental health and self-esteem in regression analyses. The predictive utility of home student status was maintained when other variables were controlled for in regression models.

Originality/value

This research suggests that the UK universities should ensure that both home and international students are adequately supported for their mental health.
Lecturers’ views
Authors: Mehar Singh Manjet Kaur
Published: February 2019

Purpose

The purpose of this paper is to investigate and understand academic English language-related challenges in listening and speaking faced by English as a foreign language (EFL) international Master students enrolled in various taught Master programs in a Malaysian university from the viewpoint/lens of 16 lecturers teaching the students.

Design/methodology/approach

This qualitative research relied upon 16 in-depth one-to-one interview sessions with 16 lecturers teaching the taught Master programs at a higher education (HE) institution in Malaysia for data collection. Data collected were coded and categorized according to themes via qualitative analysis software, NVivo.

Findings

It was found that academic English language-related challenges in listening and speaking from the viewpoint of the 16 lecturers are such as lack of discipline content knowledge to communicate, lack of confidence in communicating orally, difficulty in understanding lectures and other oral activities in the classroom, and coping with differences in learning culture.

Research limitations/implications

This study suggests policies and programs to equip lecturers and university administrators to overcome the challenges faced by the students in their academic English language practices especially in listening and speaking to ensure meaningful academic adaptation in the current context.

Originality/value

The uniqueness of this study is that it is a retrospection of the lecturers teaching EFL and English as a second language (ESL) international Master students in taught Master programs in a Southeast Asian country. The focus of the retrospection is on academic English language-related challenges in listening and speaking faced by EFL international Master students who are currently pursuing their Master education at a HE institution in Malaysia.
Measuring impact of working capital efficiency on financial performance of a firm
Authors: Prasad Punam , Sivasankaran Narayanasamy , Paul Samit , Kannadhasan Manoharan
Published: February 2019

Purpose

The purpose of this study is to introduce working capital efficiency multiplier (WCEM) as a direct profitability measure of working capital management. The existing accounting measures in the literature establish an indirect approach to study the relationship between working capital efficiency and profitability of the firms.

Design/methodology/approach

Using the help of a set of companies from CMIE Prowess database, the study introduces WCEM as a direct profitability measure of working capital efficiency.

Findings

In this study, a new direct measure of working capital efficiency is introduced which is multiplicative in nature. WCEM is a product of three components, namely, WACC, ratio of the sum of trade receivables and inventories to trade payables and ratio of net working capital (NWC) to net sales.

Practical implications

The importance of direct measure like WCEM could be enormous in performance evaluation of a firm. It can be used as an indicator for choosing a suitable investment opportunity by an investor. This is due to the fact that the firm that is highly efficient in managing working capital is less exposed to liquidity risk. At the same time, the firm is less dependent on external financing. Therefore, such firms eventually create more value for their shareholders. Another indication that WCEM provides is to gauge the bargaining power of the firm and its competitive position in the market. Lower WCEM indicates higher bargaining power of a firm across the value chain, and its superior position relative to its competitors.

Originality/value

Most of the studies on WCM are of the empirical type and there is a complete dearth on theoretical framework. Researchers hereafter can consider WCEM as one of the financial performance variables in place of the existing measures such as return on asset (ROA), return on invested capital (ROIC), return on equity (ROE), gross operating income (GOI) and net operating income (NOI) and thereby can contribute new empirical insights through their research outcomes.
Corporate governance and failure risk: evidence from Estonian SME population
Authors: Süsi Virgo , Lukason Oliver
Published: February 2019

Purpose

The purpose of this study is to find out how corporate governance is interconnected with failure risk in case of small- and medium-sized enterprises (SMEs).

Design/methodology/approach

The study is based on Estonian whole population of SMEs, in total 67,058 observations, and data are obtained from Estonian Business Register. Failure risk (FR) is portrayed with a well-known Altman et al. (2017) model, while seven variables reflecting corporate governance (CG) based on previous studies have been selected. As the method, logistic regression (LR) is applied with FR in the binary form as a dependent variable and seven CG variables as independent. The effect of firm size and age is studied with two separate LR models.

Findings

The results indicate that with the growth in manager’s age and the presence of managerial ownership, failure risk reduces. In turn, the presence of larger boards and managers having directorships in other firms leads to higher failure risk. Gender heterogeneity in the board, board tenure length and ownership concentration by means of having a majority owner are not associated with failure risk. The obtained results vary with firm size and age.

Originality/value

Unlike this study, research published on this topic earlier has used a much narrower definition of failure, mostly focused on large and listed companies, been sample based and information about corporate governance variables has often been obtained through questionnaires. All these limitations are relaxed in this population level study.
The structural impact of supply chain management teams
Authors: Li Xun , Holsapple Clyde W. , Goldsby Thomas J.
Published: February 2019

Purpose

In today’s constantly evolving global business environment, multidivisional firms (MDFs) require an organizational structure for supply chain management (SCM) that facilitates the development of supply chain agility. This research aims to investigate what structural elements of an MDF’s SCM team contribute to supply chain agility.

Design/methodology/approach

A two-sample field study was conducted. Four MDFs with top-performing supply chains (Sample 1) were first studied to identify agility-supporting structural elements. Then, quantitative data from 35 MDFs with contrasting levels of supply chain agility (Sample 2) were collected to test the theoretical propositions advanced from Sample 1 findings.

Findings

The results reveal four structural elements that exert a positive impact on an MDF’s supply chain agility: hierarchical position of the divisional top supply chain executive, scope of divisional supply chain operations, hierarchical position of the top supply chain executive at the headquarters and scope of SCM coordination by the headquarters.

Originality/value

First, this study provides a comparatively comprehensive understanding of the SCM organization structure in MDFs. Second, this study is one of the first to provide empirically supported theoretical insights about the linkage between an MDF’s organizational structure for SCM and supply chain agility.
Compensating elastic transmission losses for P‐wave attenuation estimation from sonic logs
Authors: Liang Jiabin , Müller Tobias M. , Tang Genyang , Wang Shangxu
Published: February 2019

The decay of seismic amplitude is caused by a variety of physical phenomena that can be divided broadly into elastic transmission losses (including geometrical spreading, interface transmission losses and scattering attenuation) and intrinsic attenuation, where wave energy is converted into heat due to viscous friction. The so‐called statistical averaging method is currently considered as the most advanced sonic wave attenuation estimation method, and there exist various implementations of this method. But the way elastic transmission losses – that mask the true intrinsic attenuation – are compensated for appears to be an issue and in some cases this correction has been overlooked. In this paper, we revisit the statistical averaging method for intrinsic attenuation estimation with particular focus on the role of elastic transmission losses. Through synthetic examples, we demonstrate the importance of compensating for elastic transmission losses even if the variation of velocity and density with depth is not notable. Our implementation of the method uses finite‐difference simulations thereby providing a versatile and accurate way to generate synthetic seismograms. We use a combination of elastic and viscoelastic finite‐difference simulations to demonstrate the significant error without accurate compensation of the elastic transmission losses. We apply our implementation of the method to sonic waveforms acquired in an exploration well from Browse basin, Australia. The resulting intrinsic attenuation estimates are indeed indicative of gas‐saturated zones identified from petrophysical analysis in which viscous friction are thought to be of importance.
Multi‐trace basis‐pursuit seismic inversion for resolution enhancement
Authors: Zhou Dongyong , Yin Xingyao , Zong Zhaoyun
Published: February 2019

Seismic inversion is an important tool that transfers interface information of seismic data to formation information, which renders the seismic data easily understood by geologists or petroleum engineers. In this study, a novel multi‐trace basis‐pursuit inversion method based on the Bayesian theory is proposed to enhance the vertical resolution and overcome the lateral instability of inversion results between different traces occasionally seen in the traditional trace‐by‐trace basis‐pursuit inversion method. The Markov process is initially introduced to describe the relationship between adjacent seismic traces and their correlation, which we then close couple in the equation of our new inversion method. A recursive function is further derived to simplify the inversion process by considering the particularity of the coefficient matrix in the multi‐trace inversion equation. A series of numerical‐analysis and field data examples demonstrates that both the traditional and the new methods for P‐wave impedance inversion are helpful in enhancing the resolution of thin beds that are usually difficult to discern from original seismic profiles, thus highlighting the importance of acoustic‐impedance inversion for thin bed interpretation. Furthermore, in addition to yielding thin bed inversion results with enhanced lateral continuity and high vertical resolution, our proposed method is robust to noise and cannot be easily contaminated by it, which we verify using both synthetic and field data.
A Bayesian model for lithology/fluid class prediction using a Markov mesh prior fitted from a training image
Authors: Tjelmeland Håkon , Luo Xin , Fjeldstad Torstein
Published: February 2019

We consider a Bayesian model for inversion of observed amplitude variation with offset data into lithology/fluid classes, and study in particular how the choice of prior distribution for the lithology/fluid classes influences the inversion results. Two distinct prior distributions are considered, a simple manually specified Markov random field prior with a first‐order neighbourhood and a Markov mesh model with a much larger neighbourhood estimated from a training image. They are chosen to model both horizontal connectivity and vertical thickness distribution of the lithology/fluid classes, and are compared on an offshore clastic oil reservoir in the North Sea. We combine both priors with the same linearized Gaussian likelihood function based on a convolved linearized Zoeppritz relation and estimate properties of the resulting two posterior distributions by simulating from these distributions with the Metropolis–Hastings algorithm. The influence of the prior on the marginal posterior probabilities for the lithology/fluid classes is clearly observable, but modest. The importance of the prior on the connectivity properties in the posterior realizations, however, is much stronger. The larger neighbourhood of the Markov mesh prior enables it to identify and model connectivity and curvature much better than what can be done by the first‐order neighbourhood Markov random field prior. As a result, we conclude that the posterior realizations based on the Markov mesh prior appear with much higher lateral connectivity, which is geologically plausible.
Intake of Oxidized Proteins and Amino Acids and Causative Oxidative Stress and Disease: Recent Scientific Evidences and Hypotheses
Authors: Estévez Mario , Xiong Youling
Published: February 2019

The exposure to reactive oxygen species (ROS) is an inevitable consequence of living in an aerobic world. The species contribute to the occurrence of oxidative stress in humans in which an uncontrolled production of ROS exceeds the endogenous antioxidant defences leading to the oxidative damage to essential cellular components, such as lipids, proteins, and DNA. The influence of diet on the modulation of the systemic redox status is recognized and, while some dietary components are found to be protective (that is, fruits and vegetables), others are recognized as pro‐oxidants (that is, processed meat and other animal‐source protein foods). Oxidized proteins and amino acids are potential promoters of luminal and postprandial oxidative stress; preliminary studies have actually reported noxious effects of these species in cultured cells and in experimental animals. However, the underlying pathological mechanisms remain poorly understood. The application of advanced methodological approaches based on mass spectrometric technologies and OMICS disciplines has enabled the elucidation of the molecular basis of the pathological effects of dietary oxidized proteins and amino acids. The present review collects the most recent evidences of the health risks of dietary protein oxidation and proposes reasonable hypotheses and future perspectives on the field.
Defining Regional “Standing” for Cost–Benefit Analysis in Federated Countries
Authors: Dobes Leo
Published: February 2019

Specification of “standing” – whose benefits and costs should be counted – is a crucial step in a Cost–Benefit Analysis. If it is omitted, some relevant costs and benefits may be excluded, or, conversely, wrongly included. The textbook formulation for standing is “the whole of society” for a country, but the literature is virtually silent on the issue at a sub‐national or regional level. A strictly state or regional standing can be a problem within federated countries such as Australia or the USA due to conceptual inconsistencies and resulting inefficiencies. On balance, a national perspective is to be preferred, at least as a default option.
Understanding Corporate Governance Through Learning Models of Managerial Competence
Authors: Hermalin Benjamin E. , Weisbach Michael S.
Published: February 2019

Shareholders, the board of directors, and potential future employers are continually assessing any CEO's quality. As documented by an extensive literature, such assessment plays a critical role in corporate governance because it generates incentives (good and bad), introduces assorted risks, and affects the various battles that rage among the relevant actors for corporate control. Consequently, assessment (or learning) is a key perspective from which to study, understand, and possibly even regulate corporate governance. Moreover, because learning is a behavior notoriously subject to systematic biases, assessment is a natural avenue through which to introduce behavioral and psychological insights into the study of corporate governance.
Laparoscopic distal gastrectomy for gastric cancer with simultaneous resection of para‐aortic schwannoma
Authors: Gakuhara Atsushi , Miyazaki Yasuhiro , Kurokawa Yukinori , Takahashi Tsuyoshi , Yamasaki Makoto , Makino Tomoki , Tanaka Koji , Motoori Masaaki , Kimura Yutaka , Nakajima Kiyokazu , Takiguchi Shuji , Mori Masaki , Doki Yuichiro
Published: February 2019

An asymptomatic 74‐year‐old man was diagnosed with early gastric cancer during screening. Preoperative CT revealed a 25‐mm tumor surrounded by the abdominal aorta, inferior vena cava, and left renal vein. Based on the primary tumor stage, para‐aortic lymph node metastasis was considered to be unlikely but could not be ruled out. For this reason, we planned a concurrent diagnostic and therapeutic laparoscopic resection with gastrectomy. The gastric cancer and para‐aortic tumor were successfully resected laparoscopically. The tumor was diagnosed as a schwannoma. With care and skill, we were able to resect the para‐aortic schwannoma and gastric cancer simultaneously and safely by using laparoscopic techniques.
The potential of ramie as forage for ruminants: Impacts on growth, digestion, ruminal fermentation, carcass characteristics and meat quality of goats
Authors: Zhang Hao , He Yao , Yu Lihuai , Tang Shaoxun , Tan Zhiliang , Zhou Chuanshe , Dong Li , Wang Hongrong
Published: February 2019

The objective was to evaluate the effects of ramie conserved as forage supplementation on growth, digestion, and meat quality of Liuyang black castrated goats in a 60 days feedlot study. Forty‐eight goats were randomly assigned to each of four treatments: 24% rice straw + 36% ramie residues silage + 40% concentrate; 24% rice straw + 36% raw ramie silage + 40% concentrate; 24% rice straw + 36% ramie residues hay + 40% concentrate; 24% rice straw + 36% raw ramie hay + 40% concentrate. There was an increased tendency for ADG in ramie hay treatment than that of ramie silage treatment (p = 0.067). There was an increase for the apparent digestibility of DM, CP, NDF, and ADF in the ramie hay treatment than that of ramie silage treatment (p ≤ 0.034). An increased tendency was found for C18:1n−9c (% of total fatty acids) in the longissimus dorsi muscle of raw ramie treatment versus ramie residues treatment (p ≤ 0.087). These results indicate that the ramie hay or raw ramie treatment had a tendency for improving the nutrient digestibility and meat quality of goats than that of ramie silage or ramie residues treatment, respectively.
Physicochemical characterization of goat milk produced in the Comarca Lagunera, Mexico
Authors: Isidro‐Requejo Luis M. , Meza‐Herrera César A. , Pastor‐López Francisco J. , Maldonado Jorge A. , Salinas‐González Homero
Published: February 2019

The purpose of this study was to determine goat milk physicochemical parameters during the feed scarcity season. An evaluation was made for 398 milk samples from 80 multiparous goats belonging to three different production systems: (S1) mechanized milking grazing pasture and harvested residue (alfalfa) and grain supplemented; (S2) system grazing native pasture; and (S3) system grazing native pasture and grain supplemented. The general averages were: fat (FT) 4.0 ± 0.20%, protein (PR) 3.3 ± 0.05%, lactose (LC) 4.9 ± 0.09%, nonfat solids (NFS) 8.9 ± 0.13%, total solids (TS) 14.5 ± 0.20%, temperature (TM) 24.6 ± 1.06°C, and acidity (pH) 6.7 ± 0.049. Most of the physicochemical components of milk were affected (p < 0.0001) by the production system × month interaction and production system × group × month interaction. The FT content was higher (p < 0.05) in S2 (4.56 ± 0.18) than in S1 (3.64 ± 0.20) and S3 (3.50 ± 0.20). LC differed (p < 0.05) in S2 (5.07 ± 0.08) than in S1 (4.77 ± 0.09) and S3 (4.70 ± 0.09). No differences were observed for the rest of the variables (p < 0.05) among the production systems. The study unveiled a higher content of FT, LC, NFS, PR, and TS for S2 than for S1 and S3. This higher content may be explained because S2 only grazed on herbs and shrubs, in contrast to S1 and S3 which were additionally supplemented with grain concentrates.
Hastening death and respect for dignity: Kantianism at the end of life
Authors: Kerstein Samuel
Published: February 2019

Suppose that a young athlete has just become quadriplegic. He expects to live several more decades, but out of self‐interest he autonomously chooses to engage in physician‐assisted suicide (PAS) or voluntary active euthanasia (VAE). Some of us are unsure whether he or his physician would be acting rightly in ending his life. One basis for such doubt is the notion that persons have dignity in a Kantian sense. This paper probes responses that David Velleman and Frances Kamm have suggested to the question of whether participating in PAS or VAE to benefit oneself, as the young man might, respects the dignity of persons, specified in an orthodox Kantian way. Velleman claims that it does not, while Kamm insists that, in certain circumstances, it does. I argue against Kamm's position. I go on to contend that while orthodox Kantianism might provide a basis for moral concern regarding the case of the young quadriplegic, it suffers from two serious shortcomings. First, it implies that terminally ill patients are wrong to request VAE or engage in PAS to avoid intense suffering, at least when this suffering has not yet overwhelmed their reason. Second, orthodox Kantianism implies that it is wrong for physicians to withdraw such patients from life‐sustaining treatments, even if they request it. To remedy these shortcomings, I sketch an unorthodox Kantian account of respect for the dignity of persons. This account promises to capture the idea that it would be morally problematic for doctors to help the young quadriplegic to die, but to avoid the shortcomings of an orthodox Kantian account.
Causal Inference When Counterfactuals Depend on the Proportion of All Subjects Exposed
Authors: Miles Caleb H. , Petersen Maya , van der Laan Mark J.
Published: February 2019

The assumption that no subject's exposure affects another subject's outcome, known as the no-interference assumption, has long held a foundational position in the study of causal inference. However, this assumption may be violated in many settings, and in recent years has been relaxed considerably. Often this has been achieved with either the aid of a known underlying network, or the assumption that the population can be partitioned into separate groups, between which there is no interference, and within which each subject's outcome may be affected by all the other subjects in the group via the proportion exposed (the stratified interference assumption). In this article, we instead consider a complete interference setting, in which each subject affects every other subject's outcome. In particular, we make the stratified interference assumption for a single group consisting of the entire sample. We show that a targeted maximum likelihood estimator for the i.i.d. setting can be used to estimate a class of causal parameters that includes direct effects and overall effects under certain interventions. This estimator remains doubly-robust, semiparametric efficient, and continues to allow for incorporation of machine learning under our model. We conduct a simulation study, and present results from a data application where we study the effect of a nurse-based triage system on the outcomes of patients receiving HIV care in Kenyan health clinics.
Familywise Error Control in Multi-Armed Response-Adaptive Trials
Authors: Robertson D. S. , Wason J. M. S.
Published: February 2019

Response-adaptive designs allow the randomization probabilities to change during the course of a trial based on cumulated response data so that a greater proportion of patients can be allocated to the better performing treatments. A major concern over the use of response-adaptive designs in practice, particularly from a regulatory viewpoint, is controlling the type I error rate. In particular, we show that the naïve z-test can have an inflated type I error rate even after applying a Bonferroni correction. Simulation studies have often been used to demonstrate error control but do not provide a guarantee. In this article, we present adaptive testing procedures for normally distributed outcomes that ensure strong familywise error control by iteratively applying the conditional invariance principle. Our approach can be used for fully sequential and block randomized trials and for a large class of adaptive randomization rules found in the literature. We show there is a high price to pay in terms of power to guarantee familywise error control for randomization schemes with extreme allocation probabilities. However, for proposed Bayesian adaptive randomization schemes in the literature, our adaptive tests maintain or increase the power of the trial compared to the z-test. We illustrate our method using a three-armed trial in primary hypercholesterolemia.
Potential roles of artificial intelligence learning and faecal immunochemical testing for prioritisation of colonoscopy in anaemia
Authors: Ayling Ruth M. , Lewis Stephen J. , Cotter Finbarr
Published: February 2019

Iron deficiency anaemia (IDA) is the most common cause of anaemia and a frequent indication for colonoscopy, although the prevalence of colorectal cancer (CRC) in IDA is low. Measurement of faecal haemoglobin by immunochemical techniques (FIT) is used to detect symptomatic patients. We studied FIT in patients with anaemia attending a gastroenterology clinic in Plymouth and looked at an artificial intelligence (AI) learning algorithm (ColonFlag™) in these patients, together with a cohort who had undergone colonoscopy for IDA in London. Of 592 patients referred on the basis of haemoglobin concentration, 21 (3.5%) had CRC. Using ColonFlag™, rather than haemoglobin concentration, in combination with symptoms, would have resulted in prioritisation of 304 patients for urgent referral rather than 592. One CRC would have been missed but might have been detected by FIT, which was not available in this case. In patients aged <55 years in whom the incidence of CRC is low, 15 rather than 109 patients would have been prioritised for urgent referral with no cancers missed. FIT has a high negative predictive value in IDA so its use may enable some patients to avoid investigation and AI learning may be a more useful trigger than haemoglobin concentration for urgent referral for colonoscopy.
Evaluation of the accuracy of multiparametric MRI for predicting prostate cancer pathology and tumour staging in the real world: an multicentre study
Authors: Kam Jonathan , Yuminaga Yuigi , Krelle Matthew , Gavin Dominic , Koschel Samantha , Aluwihare Kushlan , Sutherland Tom , Skinner Sarah , Brennan Janelle , Wong Lih‐Ming , Louie‐Johnsun Mark
Published: February 2019

Objectives

To assess the accuracy of multiparametric magnetic resonance imaging (mpMRI) for the detection of significant prostate cancer in men undergoing radical prostatectomy (RP) in an Australian multicentre setting, and to assess concordance between mpMRI and RP for local tumour staging and index lesion locations.

Patients and Methods

Men who underwent mpMRI within 12 months of RP between January 2013 and August 2016 at three Australian sites were included (Central Coast, NSW, St Vincents Hospital, Melbourne, Vic., and Bendigo Hospital, Vic.). The results of mpMRI were compared with the final RP specimen to analyse the performance of mpMRI for significant prostate cancer detection, index lesion localization, prediction of T3 disease and lymph node metastasis. A comparison between mpMRI cases performed using the technical and reporting specifications of Prostate Imaging Reporting and Data System (PI‐RADS) version 1 and version 2 was also performed. Data analysis was performed using spss 24.0.

Results

A total of 235 cases were included for analysis. mpMRI PI‐RADS score ≥3 had a 91% sensitivity and 95% positive predictive value (PPV) for significant prostate cancer at RP. The overall concordance between index lesion location on mpMRI and RP specimen was 75%. The sensitivity for predication of significant prostate cancer was higher in the PI‐RADS version 2 cases compared with PI‐RADS version 1 (87–99%; P = 0.005). Index lesion concordance was higher in the PI‐RADS version 2 group (68% vs 91%; P = 0.002). mpMRI had a 38% sensitivity, 95% specificity, 90% PPV and 57% negative predictive value for extraprostatic disease. Sensitivity for prediction of T3 disease improved from 30% to 62% (P = 0.008) with PI‐RADS version 2.

Conclusions

In patients undergoing RP, an abnormal mpMRI is highly predictive (95% PPV) of significant prostate cancer, with an index lesion concordance of 75%. There has been a significant improvement in accuracy after the adoption of PI‐RADS version 2 technical specifications and reporting criteria; however; further study is required to determine if this is attributable to improved experience with mpMRI or changes in the PI‐RADS system.
Function of cAMP scaffolds in obstructive lung disease: Focus on epithelial‐to‐mesenchymal transition and oxidative stress
Authors: Zuo Haoxiao , Cattani‐Cavalieri Isabella , Valença Samuel Santos , Musheshe Nshunge , Schmidt Martina
Published: February 2019

Over the past decades, research has defined cAMP as one of the central cellular nodes in sensing and integrating multiple pathways and as a pivotal role player in lung pathophysiology. Obstructive lung disorders, such as chronic obstructive pulmonary disease (COPD), are characterized by a persistent and progressive airflow limitation and by oxidative stress from endogenous and exogenous insults. The extent of airflow obstruction depends on the relative deposition of different constituents of the extracellular matrix, a process related to epithelial‐to‐mesenchymal transition, and which subsequently results in airway fibrosis. Oxidative stress from endogenous and also from exogenous sources causes a profound worsening of COPD. Here we describe how cAMP scaffolds and their different signalosomes in different subcellular compartments may contribute to COPD. Future research will require translational studies to alleviate disease symptoms by pharmacologically targeting the cAMP scaffolds.

Linked Articles

This article is part of a themed section on Adrenoceptors—New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc