bluuebunny/crossref_metadata_2025 huggingface dataset:
Linking Normative Models of Natural Tasks to Descriptive Models of Neural Response
Authors: Jaini Priyank , Burge Johannes
Published: July 2017

Understanding how nervous systems exploit task relevant properties of sensory stimuli to perform natural tasks is fundamental to the study of perceptual systems. However, there are few formal methods for determining which stimulus properties are most useful for a given task. As a consequence, it is difficult to develop principled models for how to compute task-relevant latent variables from natural signals, and it is difficult to evaluate descriptive models fit to neural response. Accuracy Maxmization Analysis (AMA) is a recently developed Bayesian method for finding the optimal task-specific filters (receptive fields). Here, we introduce AMA-Gauss, a new faster form of AMA that incorporates the assumption that the class-conditional filter responses are Gaussian distributed. Next, we use AMA-Gauss to show that its assumptions are justified for two fundamental visual tasks: retinal speed estimation and binocular disparity estimation. Then, we show that AMA-Gauss has striking formal similarities to popular quadratic models of neural response: the energy model and the Generalized Quadratic Model (GQM). Together, these developments deepen our understanding of why the energy model of neural response have proven useful, improve our ability to evaluate results from subunit model fits to neural data, and should help accelerate psychophysics and neuroscience research with natural stimuli.
Receptor-Based Mechanism of Cell Memory and Relative Sensing in Mammalian Signaling Networks
Authors: Lyashenko Eugenia , Niepel Mario , Dixit Purushottam D. , Lim Sang Kyun , Sorger Peter K. , Vitkup Dennis
Published: July 2017

Detecting relative rather than absolute changes in external signals enables cells to make decisions in fluctuating environments and diverse biological contexts. However, how mammalian signaling networks store the memories of past stimuli and use them to compute relative signals is not well understood. Using the growth factor-activated PI3K-Akt signaling pathway, we develop computational and analytical models, and experimentally validate a novel mechanism of relative sensing in mammalian cells. This non-transcriptional mechanism relies on a new form of cellular memory, where cells effectively encode past stimulation levels in the abundance of cognate receptors on the cell surface. We show the robustness and specificity of the relative sensing for two physiologically important ligands, epidermal growth factor (EGF) and hepatocyte growth factor (HGF), and across wide ranges of background stimuli. The described memory and sensing mechanism could play a role in multiple other sensory cascades where stimulation leads to a proportional reduction in the abundance of cell surface receptors.
A tale of two universities: graduates perceived value of entrepreneurship education
Authors: Jones Paul , Pickernell David , Fisher Rebecca , Netana Celia
Published: July 2017

Purpose

The purpose of this paper is to evaluate career impact of entrepreneurship education (EE) considering evidence drawn from a quantitative study of alumni within two UK higher education institutions (HEIs) from a retrospective perspective. The findings inform the value of the EE experience and its impact on both self-employability and wider employability career choices. This study will be of relevance to both enterprise support agencies and government policy makers.

Design/methodology/approach

This research study considers evidence drawn from an online quantitative survey of EE within two UK HEIs. The survey evaluated a range of issues including course design, programme satisfaction, impact, career outcomes and respondents demographics. Over 80 respondents completed the survey in full which was analysed using a range of bivariate techniques.

Findings

The evidence suggested here indicates that EE programmes provide value both in terms of helping to enable business start-ups and also in supporting other career paths, through the enterprising knowledge and skill sets graduates acquire during their specialised studies. This study contributes to the literature by recognising and measuring these contributions. For example, this study enables discernment between different EE course components and their value for different career outcomes.

Research limitations/implications

The study recognises the limitations of this survey data in terms of the size of the sample, number of HEIs evaluated and its point in time design.

Practical implications

The HEI sector must evaluate its practices and measure the effectiveness of its graduates in terms of achieving sustainable business start-up. In course design, the evidence suggested that students value both the enterprising and entrepreneurial skills and knowledge components and discern value between them in their later careers. The findings suggest that EE graduates typically experience portfolio careers with multiple occupations in different sectors and roles within both employment and self-employment. Thus it is important that EE programme design includes both enterprising and entrepreneurial components to meet the future requirements of their graduates postgraduation.

Originality/value

This study contributes new evidence regarding the value of EE in UK HEIs. This evidence should inform course design and policy makers regarding the value of EE in creating self-employment and creating enterprising employees.
Undergraduate perceptions of social media proficiency and graduate employability
Authors: Sutherland Karen , Ho Susie
Published: July 2017

Purpose

The purpose of this paper is to explore undergraduate student attitudes towards the inclusion of social media training within higher education pedagogy, student perceptions of social media proficiency as professional expertise and its impact on graduate employability.

Design/methodology/approach

In all, 81 undergraduate students studying medicine, law, science and arts volunteered to complete an online survey. Questions examined student attitudes towards the delivery of social media pedagogy at university and the perceived benefits of social media proficiency.

Findings

Participants stated that social media skills should be taught in optional classes (85 per cent) covering generic competencies (56 per cent). The majority (91 per cent) of respondents reported that social media skills and training were valuable for employability.

Research limitations/implications

This was a pilot study and was therefore limited by the self-selection of participants, sample size and geographic location.

Practical implications

This study identifies that undergraduates across a range of disciplines are receptive to developing professionally relevant social media skills within higher education pedagogy and identify a link between social media proficiency and graduate employability.

Originality/value

Despite the increasing necessity for social media skills in professional environments, few studies have examined the teaching of social media skills as a core competency in higher education. Instead, social media is largely examined in relation to curriculum delivery and student engagement. This study explores attitudes towards the delivery of social media pedagogy at university and the perceived benefits of social media proficiency exclusively from the viewpoint of undergraduate students, to provide an alternative insight rarely explored in the literature.
Green maintainability design criteria for nanostructured titanium dioxide (TiO2) façade coatings
Authors: Chew Michael Y.L. , Conejos Sheila , Law Jessie Sze Long
Published: July 2017

Purpose

Nanostructured titanium dioxide (TiO2) coatings can potentially address the current surge in façade cleaning cost, maintenance and labour problems. The purpose of this paper is to investigate potential maintainability issues and design challenges concerning the effective performance of TiO2façade coatings’ hydrophilic properties, especially in tropical environments such as Singapore. This paper aims to establish a list of green maintainability design criteria to help minimise future TiO2façade coating issues when this coating is applied on commercial buildings with concrete and stonemasonry façade materials.

Design/methodology/approach

A mixed-mode approach that includes a literature review, site investigation, instrumental case studies and expert interviews is used in this study.

Findings

TiO2coatings help improve façade performance whilst offering environmental benefits to society. This study reports that green maintainability design criteria are vital requirements in designing sustainable buildings at the outset. The identified defects and issues will aid in ensuring the effectiveness of TiO2application in building façades.

Originality/value

This study acts as a foundation for future researchers to strengthen this little researched area, serves as a useful guide in preventing possible TiO2coating issues and promotes industry awareness of the use of TiO2façade coatings.
The effect of joint clearance on the dynamic behavior of a needle driver mechanism in a typical sewing machine
Authors: Salahshoor Esmaeil , Ebrahimi Saeed
Published: July 2017

Purpose

The purpose of this paper is to investigate the effect of joint clearance on the behavior of a needle driver mechanism (a slider-crank linkage) of a typical sewing machine with an imperfect joint between the coupler and the slider (including needle).

Design/methodology/approach

In order to model the clearance, the momentum exchange approach is used. The Lankarani and Nikravesh’s continuous contact force model is used to model the contact force, and the modified Coulomb’s friction law represents the friction between sliding members. The penetration force applied on the needle by fabric is chosen based on an experimental data in the literature. The dynamic response is validated for the existing properties in the literature without considering the penetration force.

Findings

It is shown that the clearance joint made considerable effect on the dynamic response of the system. The rough changes of the needle acceleration and jerk are obvious. The base reaction force changed roughly and did not vary as smooth as that of the mechanism with ideal joint. So, clearance joint in the mechanism could lead to an undesirable vibration in the system. Furthermore, the crank driver must provide a non-smooth moment on the crank to keep the crank rotational velocity constant. Moreover, reducing the clearance size sufficiently could make the dynamic response closer to that of the mechanism with ideal joint. In addition, smoother crank moment could be required if the clearance size is reduced sufficiently. Furthermore, the rough change of the base reaction force which can represent the vibration caused by the mechanism on the fixed frame could be reduced if the clearance size is small enough.

Originality/value

Lockstitch sewing machine is one of the most common apparel industrial machines. The needle driver mechanism of a sewing machine could have an important role for proper stitch forming. On the other hand, clearances are inevitable in assemblage of mechanisms to allow the relative motion between the members. This clearance is due to machining tolerances, wear, material deformations, and imperfections, and it can worsen mechanism performance such as precision, dynamic behavior and vibration. Unfortunately, despite the importance of the dynamic behavior of the needle driver mechanism from practical point of view, very little publications have focused especially on the investigation of the effect of clearance joint on the dynamic behavior of the sewing machine which could lead to undesired vibration of the system and shorter lifetime as a result. In this paper, the dynamic behavior of the system including, needle velocity and acceleration, crank moment and base reaction force was compared with that of the ideal mechanism. Finally, the effect of clearance size on the dynamic behavior of the system was investigated.
Approximating interior bounded box of 3D character mesh model based on its skeleton and symmetry
Authors: Xu Hanxiang , Guo Shihui , Yao Junfeng , Thalmann Nadia Magnenat
Published: July 2017

Purpose

In the process of robot shell design, it is necessary to match the shape of the input 3D original character mesh model and robot endoskeleton, in order to make the input model fit for robot and avoid collision. So, the purpose of this paper is to find an object of reference, which can be used for the process of shape matching.

Design/methodology/approach

In this work, the authors propose an interior bounded box (IBB) approach that derives from oriented bounding box (OBB). This kind of box is inside the closed mesh model. At the same time, it has maximum volume which is aligned with the object axis but is enclosed by all the mesh vertices. Based on the IBB of input mesh model and the OBB of robot endoskeleton, the authors can complete the process of shape matching. In this paper, the authors use an evolutionary algorithm, covariance matrix adaptation evolution strategy (CMA-ES), to approximate the IBB based on skeleton and symmetry of input character mesh model.

Findings

Based on the evolutionary algorithm CMA-ES, the optimal position and scale information of IBB can be found. The authors can obtain satisfactory IBB result after this optimization process. The output IBB has maximum volume and is enveloped by the input character mesh model as well.

Originality/value

To the best knowledge of the authors, the IBB is first proposed and used in the field of robot shell design. Taking advantage of the IBB, people can quickly obtain a shell model that fit for robot. At the same time, it can avoid collision between shell model and the robot endoskeleton.
Two efficient methods for solving Schlömilch’s integral equation
Authors: AL-Jawary Majeed Ahmed , Radhi Ghassan Hasan , Ravnik Jure
Published: July 2017

Purpose

In this paper, the exact solutions of the Schlömilch’s integral equation and its linear and non-linear generalized formulas with application are solved by using two efficient iterative methods. The Schlömilch’s integral equations have many applications in atmospheric, terrestrial physics and ionospheric problems. They describe the density profile of electrons from the ionospheric for awry occurrence of the quasi-transverse approximations. The paper aims to discuss these issues.

Design/methodology/approach

First, the authors apply a regularization method combined with the standard homotopy analysis method to find the exact solutions for all forms of the Schlömilch’s integral equation. Second, the authors implement the regularization method with the variational iteration method for the same purpose. The effectiveness of the regularization-Homotopy method and the regularization-variational method is shown by using them for several illustrative examples, which have been solved by other authors using the so-called regularization-Adomian method.

Findings

The implementation of the two methods demonstrates the usefulness in finding exact solutions.

Practical implications

The authors have applied the developed methodology to the solution of the Rayleigh equation, which is an important equation in fluid dynamics and has a variety of applications in different fields of science and engineering. These include the analysis of batch distillation in chemistry, scattering of electromagnetic waves in physics, isotopic data in contaminant hydrogeology and others.

Originality/value

In this paper, two reliable methods have been implemented to solve several examples, where those examples represent the main types of the Schlömilch’s integral models. Each method has been accompanied with the use of the regularization method. This process constructs an efficient dealing to get the exact solutions of the linear and non-linear Schlömilch’s integral equation which is easy to implement. In addition to that, the accompanied regularization method with each of the two used methods proved its efficiency in handling many problems especially ill-posed problems, such as the Fredholm integral equation of the first kind.
Can foreign aid motivate institutional reform? An evaluation of the HIPC Initiative
Authors: Schlosky Minh Tam , Young Andrew
Published: July 2017

Purpose

A number of political economy concerns are associated with the provision of foreign aid to developing economies. These concerns suggest that foreign aid is likely to have harmful effects on a recipient’s institutional quality, and that attempts to give aid conditional on policy and institutional reforms are unlikely to succeed. Established in 1996, the Heavily Indebted Poor Country (HIPC) Initiative is a comprehensive, structured attempt to provide multilateral foreign aid conditional on reforms in recipient countries. The purpose of this paper is to evaluate its effectiveness at affecting institutional reform in participating countries.

Design/methodology/approach

The authors document how participating countries fared in terms of the quality of their policies and institutions. The authors employ the Fraser Institute’s Economic Freedom of the World index as a measure of economic institutions, and the Freedom House political rights (PR) and civil liberties indices as measures of PR and protections. Based on these measures, the authors report unconditional statistics (e.g. average changes) and also regressions of changes in the measures on HIPC Initiative aid allocations and other controls.

Findings

The authors find that most participating countries experienced either meager increases or outright decreases in institutional quality. The regression results provide no evidence that the Initiative affects meaningful reforms.

Originality/value

The potential for foreign aid to have deleterious effects on the institutional quality of recipient countries has been of increasing concern to students of economic development. Such effects can have important implications for entrepreneurial activity in these countries. The HIPC Initiative is specifically designed to acknowledge and, indeed, overcome these concerns, leading to actual increases in institutional quality of recipient countries. To the authors’ knowledge, this work is the first to assess whether the promise of the HIPC Initiative is being fulfilled.
Hybrid scheduling and maintenance problem using artificial neural network based meta-heuristics
Authors: Abedi Mehdi , Seidgar Hany , Fazlollahtabar Hamed
Published: July 2017

Purpose

The purpose of this paper is to present a new mathematical model for the unrelated parallel machine scheduling problem with aging effects and multi-maintenance activities.

Design/methodology/approach

The authors assume that each machine may be subject to several maintenance activities over the scheduling horizon and a machine turn into its initial condition after maintenance activity and the aging effects start anew. The objective is to minimize the weighted sum of early/tardy times of jobs and maintenance costs.

Findings

As this problem is proven to be non-deterministic polynomial-time hard (NP-hard), the authors employed imperialist competitive algorithm (ICA) and genetic algorithm (GA) as solution approaches, and the parameters of the proposed algorithms are calibrated by a novel parameter tuning tool called Artificial Neural Network (ANN). The computational results clarify that GA performs better than ICA in quality of solutions and computational time.

Originality/value

Predictive maintenance (PM) activities carry out the operations on machines and tools before the breakdown takes place and it helps to prevent failures before they happen.
Advance selling with part payment for new to-be-released products
Authors: Tang Wangmei , Ang Sheng
Published: July 2017

Purpose

The paper aims to study a strategy of advance selling with part payment (ADP) in which pre-ordering consumers are required to pay a portion of advance price first and then pay the rest in the spot period to complete the order. The authors compare the ADP strategy with strategies of advance selling with full payment (ADF) and no advance selling (NA) from the perspective of sellers.

Design/methodology/approach

The paper proposes a two-period pricing model with price-off promotion in the first period for a market consisting of consumers and a single seller. For each strategy (i.e. NA, ADF and ADP), solutions to the seller’s optimal order quantity in the spot period, optimal advance price and prepayment in the advance period are derived by backward conduction. Numerical study is also used to obtain straightforward insights.

Findings

Advance price of ADF is lower than that of ADP. Order quantity of ADF is higher than that of ADP. ADP brings more profit than the other two selling strategies, i.e. NA and ADF, when ADP’s implementing conditions are satisfied. While ADF is effective only when unit cost is low, ADP is applicable irrespective of whether the cost is low.

Originality/value

Existing researchers on advance selling mainly focus on the ADF strategy. The paper pays attention to different payment mechanisms in advance selling and steps further to propose a new form of advance selling, i.e. the ADP strategy. The effects of ADP on consumer’s purchasing behavior and seller’s marketing decisions are analyzed.
Simulation based study on improving the transient response quality of turbocharged diesel engines
Authors: Mishra Rakesh , Saad Syed Mohammad
Published: July 2017

Purpose

Use of fossil fuels in automotive sector is one of the primary causes of greenhouse emissions. The automotive engines need to perform at their best efficiency point to limit these emissions. Most of the quality indicators in this regard are based on near steady state global operational characteristics for engines without considering local performance. In the present study, extensive numerical simulations have been carried out covering a wide range of steady state and transient operating conditions to quantify interaction of turbocharger with engines through turbo lag phenomena which may cause increased emissions during the load change conditions. Furthermore possible innovations have been explored to minimize turbo lag phenomena. The paper aims to discuss these issues.

Design/methodology/approach

In this paper quality indicators have been developed to quantify the performance of turbocharged diesel engine under the transient event of rapid change in fueling rate which has been rarely investigated. The rate of fueling is changed from 40 mm3/injection to 52 mm3/injection at 1,000 rpm engine speed which corresponds to normal operating condition. To improve quality of transient response, torque assistance method and reduction of inertia of compressor wheel have been used. Parametric study has been undertaken to analyze the quality indicators such as outlet pressure of the compressor and the compressor speed. The turbo lag is quantified to obtain the close to optimal transient response of turbocharged diesel engine.

Findings

It has been shown that, with torque assist the transient response of the internal combustion engine is significantly improved. On the other hand, marginal improvement in transient response is observed by the reduction in inertia of the compressor wheel.

Research limitations/implications

The findings indicate that turbo lag can be minimized by providing torque assistance by active and passive means.

Practical implications

The developed methods can be used in practice for efficient operation of vehicles.

Social implications

The work carried out in the paper provides a way to minimize harmful emissions.

Originality/value

The quality indicators developed provide a quantitative measure of turbo lag phenomena and address the above mentioned problems.
Systematic risk-analysis to support a living maintenance programme for railway infrastructure
Authors: Söderholm Peter , Nilsen Terje
Published: July 2017

Purpose

The purpose of this paper is to describe an application of an effective risk-based methodology to support a living maintenance programme for railway infrastructure.

Design/methodology/approach

The overall research strategy is a single case study of switches and crossings at the Iron Ore Line in northern Sweden. The analysis was performed as a risk workshop guided by a methodology that integrates reliability-centred maintenance and barrier analysis.

Findings

The applied methodology is valuable to systematise and improve the existing maintenance programme, as well as supporting a continued living maintenance programme.

Research limitations/implications

The single case study approach may decrease the validity of the achieved results. However, similar case studies corroborate the results, which affect the validity in a positive way.

Practical implications

The resulting maintenance programme is effective, through compliance with external requirements, and more efficient, through improvements of tasks and intervals.

Social implications

An enhanced railway infrastructure maintenance programme contributes to improved safety, punctuality, and costs. Hence, railway becomes a more attractive mode of transport. Thereby, it also supports a safety performance of the railway that society is willing to pay for.

Originality/value

Significant improvements of the maintenance programme are achieved through adjustment of inspection intervals and tasks. The results also support the development of indicators, monitoring, and continuous improvement.
Design and integration of a piezoelectric vibrating device in an LTCC structure
Authors: Belavič Darko , Bradeško Andraž , Kos Tomaz , Rojac Tadej
Published: July 2017

Purpose

In this contribution, the design and integration of a piezoelectric vibrating device into low-temperature, co-fired ceramic (LTCC) structures are presented and discussed. The mechanical vibration of the diaphragm was stimulated with a piezoelectric actuator, which was integrated onto the diaphragm. Three different methods for the integration were designed, fabricated and evaluated.

Design/methodology/approach

The vibrating devices were designed as an edge-clamped diaphragm with an integrated piezoelectric actuator at its centre, whose role is to stimulate the vibration of the diaphragm via the converse piezoelectric effect. The design and feasibility study of the vibrating devices was supported by analytical methods and finite-element analyses.

Findings

The benchmarking of the ceramic vibrating devices showed that the thick-film piezoelectric actuator responds weakly in comparison with both the bulk actuators. On the other hand, the thick-film actuator has the lowest dissipation factor and it generates the largest displacement of the diaphragm with the lowest driving voltage. The resonance frequency of the vibrating device with the thick-film actuator is the most sensitive for an applied load (i.e. mass or pressure).

Research limitations/implications

Research activity includes the design and the fabrication of a piezoelectric vibrating device in the LTCC structure. The research work on the piezoelectric properties of integrated piezoelectric actuators was limited.

Practical implications

Piezoelectric vibrating devices were used as pressure sensors.

Originality/value

Piezoelectric vibrating devices could be used not only for pressure sensors but also for other type of sensors and detectors and for microbalances.
How important are earnings announcements in China?
Authors: Zou Liping , Wilson William Robert
Published: July 2017

Purpose

This paper tests the information efficiency of the Chinese stock market to judge if it contravenes the Fama (1965) efficient market hypothesis. Following China’s stock market reforms the market has grown in international importance, however many find information difficult to obtain and interpret.

Design/methodology/approach

The relative importance of earnings announcements is quantified using cross-sectional regressions of calendar-year annual returns R_i on returns in the four quarterly earnings announcement windows return R_j. The metric developed by Ball and Shivakumar (2008) and Basu et al. (2013) is used to determine the level of new information contained in earnings announcements.

Findings

Analysis reveals earnings announcements contain little new information of value, thus demonstrating the Chinese markets are not informationally efficient. Therefore, investors cannot automatically assume assets are always correctly priced, as they are in other established markets.

Originality/value

Major structural changes were made to Chinese equity markets in 2004, with the introduction of the Qualified Foreign Institutional Investors scheme. At the same time, firms were required to make earnings announcements on a quarterly basis. This paper is the first to test the impact of these changes on the information value of earnings announcements since the changes.
Detecting fraud in Chinese listed company balance sheets
Authors: Wei Yi , Chen Jianguo , Wirth Carolyn
Published: July 2017

Purpose

This paper aims to investigate the links between accounting values in Chinese listed companies’ balance sheets and the exposure of their fraudulent activities.

Design/methodology/approach

Every balance sheet account is proposed to be a potential vehicle to manipulate financial statements.

Findings

Other receivables, inventories, prepaid expenses, employee benefits payables and long-term payables are important indicators of fraudulent financial statements. These results confirm that asset account manipulation is frequently carried out and cast doubt on earlier conclusions by researchers that inflation of liabilities is the most common source of financial statement manipulation.

Originality/value

Previous practices of solely scaling balance sheet values by assets are revealed to produce spurious relationships, while scaling by both assets and sales effectively detects fraudulent financial statements and provides a useful fraud prediction tool for Chinese auditors, regulators and investors.
Does corporate social responsibility disclosure improve firm investment efficiency?
Authors: Zhong Ma , Gao Lucia
Published: July 2017

Purpose

The purpose of this paper is to investigate the impact of corporate social responsibility (CSR) disclosure on firm-level investment efficiency.

Design/methodology/approach

An econometric model is used to estimate the impact of CSR reporting on investment efficiency on a sample of listed Chinese firms during the period from 2010 to 2013. Financial reporting quality is included in the model as a control variable. Investment efficiency is estimated based on existing models. Two scenarios are identified: under-investment and over-investment.

Findings

The results provide evidence of a higher level of investment efficiency for CSR reporting firms than for non-reporting firms. This relationship is, however, more pronounced in the over-investment scenario than in the under-investment scenario. In addition, the association between CSR disclosure and investment efficiency is stronger for firms with lower financial reporting quality (FRQ). These findings support the hypothesis that CSR disclosure provides effective incremental information that contributes to reduce information asymmetry and promote investment efficiency.

Originality/value

This is the first paper that directly tests the association between CSR disclosure and firm-level investment efficiency. The results suggest that firms and investors should consider the effect of CSR disclosure on information asymmetry and its impact on the availability and cost of capital. This work also contributes to the understanding of the economic impacts of CSR disclosure and provides arguments for regulatory entities to enforce CSR disclosure.
Managerial opportunism and real activities manipulation: evidence from option backdating firms
Authors: Amoah Nana Y. , Anderson Anthony , Bonaparte Isaac , Muzorewa Susan
Published: July 2017

Purpose

This study aims to examine the use of real activities manipulation by firms implicated in the stock option backdating scandal.

Design/methodology/approach

The real activity manipulation measures are as follows: abnormal R&D expense, abnormal SG&A expense, abnormal production cost and abnormal cash flow from operations. Using a sample of firms alleged to have backdated options during the period 1998-2006 and non-backdating one-on-one matched firms, a separate regression is run for each of the real activity manipulation measures (dependent variables) on backdating and other variables.

Findings

The authors report unusually low R&D and unusually low SG&A expenses among the backdating firms. They also find evidence of unusually high production costs among backdating firms compared to the matched firms.

Research limitations/implications

The findings imply that backdating firms are more aggressive in the use of real activities to manipulate earnings and the use of real activities appears to be opportunistic.

Originality/value

The study contributes to the literature by providing evidence of the use of real activities manipulation by firms under investigation for fraud. The authors also add to the debate on whether the use of stock options as part of compensation aligns the interest of management with the interest of shareholders.
The evaluation of non‐invasive multi‐slice spiral computed tomography‐based indices for the diagnosis and prognosis prediction of liver cirrhosis
Authors: Feng Ling Mei , Lei Shu Juan , Zeng Xin , Wang Pei Qin , Chen Ru Tan , Wang Jian , Sheng Xia , Shi Pei Mei , Yuan Zong Li , Xie Wei Fen
Published: July 2017

OBJECTIVE

This study aimed to evaluate easily available computed tomography (CT)‐based parameters for assessing the presence and severity of cirrhosis and predicting complications in Chinese patients with cirrhosis.

METHODS

CT‐based morphological indices were determined in 167 patients with cirrhosis and 244 healthy volunteers. The correlation of morphological indices with Child–Pugh score and cirrhotic complications was analyzed using Spearman's correlation analysis. The area under the receiver operating characteristic curve (AUROC) was used to analyze the diagnostic performance of the indices. Sensitivity and specificity were determined.

RESULTS

Patients with cirrhosis had a lower total liver volume (TLV) and a larger total splenic volume (SV) than healthy individuals. There was a significant difference in the portal venous diameter, splenic venous diameter and portal venous cross‐sectional area between the two groups. A low TLV/SV ratio was strongly associated with liver cirrhosis; with a cut‐off value of 4.27 for the diagnosis of cirrhosis TLV/SV had a sensitivity of 87.7% and a specificity of 84.9%, and AUROC of 0.921. Further analysis showed that TLV/SV was accurate in discriminating between mild and moderate/severe cirrhosis and could be used for predicting complications of cirrhosis.

CONCLUSION

The easily available parameters of CT can accurately evaluate the severity of cirrhosis in Chinese patients.
The Hazard of Teetering at the Top and Being Tied to the Bottom: The Interactive Relationship of Power, Stability, and Social Dominance Orientation with Work Stress
Authors: Feenstra Sanne , Jordan Jennifer , Walter Frank , Yan Jin , Stoker Janka I.
Published: July 2017

This study examines the roles of power, stability, and social dominance orientation (SDO) for work stress. Initial laboratory research has demonstrated that power and the stability of one's power position interact to influence stress. Using a sample of Chinese managers, we replicate and extend this finding in an organisational field setting, illustrating that the interactive role of power and stability hinges on individuals' SDO. Individuals higher (but not lower) in SDO experienced more work stress in unstable high‐power and stable low‐power positions, compared to their counterparts in stable high‐power and unstable low‐power positions. These results underscore the role of stability for understanding the power–stress relationship and emphasise individual differences in needs and motivations as an important boundary condition.
CXCL12 and CXCR7 are relevant targets to reverse cell adhesion‐mediated drug resistance in multiple myeloma
Authors: Waldschmidt Johannes M. , Simon Anna , Wider Dagmar , Müller Stefan J. , Follo Marie , Ihorst Gabriele , Decker Sarah , Lorenz Joschka , Chatterjee Manik , Azab Abdel K. , Duyster Justus , Wäsch Ralph , Engelhardt Monika
Published: July 2017

Cell adhesion‐mediated drug resistance (CAM‐DR) by the bone marrow (BM) is fundamental to multiple myeloma (MM) propagation and survival. Targeting BM protection to increase the efficacy of current anti‐myeloma treatment has not been extensively pursued. To extend the understanding of CAM‐DR, we hypothesized that the cytotoxic effects of novel anti‐myeloma agents may be abrogated by the presence of BM stroma cells (BMSCs) and restored by addition of the CXCL12 antagonist NOX‐A12 or the CXCR4 inhibitor plerixafor. Following this hypothesis, we evaluated different anti‐myeloma agents alone, with BMSCs and when combined with plerixafor or NOX‐A12. We verified CXCR4, CD49d (also termed ITGA4) and CD44 as essential mediators of BM adhesion on MM cells. Additionally, we show that CXCR7, the second receptor of stromal‐derived‐factor‐1 (CXCL12), is highly expressed in active MM. Co‐culture proved that co‐treatment with plerixafor or NOX‐A12, the latter inhibiting CXCR4 and CXCR7, functionally interfered with MM chemotaxis to the BM. This led to the resensitization of MM cells to the anti‐myeloma agents vorinostat and pomalidomide and both proteasome inhibitors bortezomib and carfilzomib. Within a multicentre phase I/II study, NOX‐A12 was tested in combination with bortezomib‐dexamethasone, underlining the feasibility of NOX‐A12 as an active add‐on agent to antagonize myeloma CAM‐DR.
Comparative assessment of the efficacy of onabotulinumtoxinA and oral therapies (anticholinergics and mirabegron) for overactive bladder: a systematic review and network meta‐analysis
Authors: Drake Marcus J. , Nitti Victor W. , Ginsberg David A. , Brucker Benjamin M. , Hepp Zsolt , McCool Rachael , Glanville Julie M. , Fleetwood Kelly , James Daniel , Chapple Christopher R.
Published: July 2017

Objectives

To compare the efficacy of onabotulinumtoxinA, mirabegron, and anticholinergics in adults with idiopathic overactive bladder (OAB) using network meta‐analysis (NMA).

Patients and Methods

Information sources were searched for blinded randomised controlled trials (RCTs), of ≥2 weeks duration, comparing any dose of onabotulinumtoxinA, eligible oral/transdermal anticholinergics, or mirabegron, with each other or placebo, in adults with OAB. Bayesian random‐effects models were used to synthesise the results at week 12: NMA for responder analyses and network meta‐regression (NMR) for change from baseline analyses. The NMR was used to adjust for differences in baseline severity between studies. Sensitivity analysis, excluding studies considered to be at a high risk of methodological bias, was conducted.

Results

In all, 56 RCTs were included in the networks. For each outcome, results are reported for all licensed treatment doses. For each NMR, results are based on patients with an average number of episodes of the outcome at baseline. After 12 weeks, all treatments were more efficacious than placebo. Patients who received onabotulinumtoxinA (100 U) had, on average, the greatest reductions in urinary incontinence episodes (UIE), urgency episodes, and micturition frequency, and the highest odds of achieving decreases of 100% and ≥50% from baseline in UIE/day. When comparing onabotulinumtoxinA with other pharmacotherapies, mean differences favoured onabotulinumtoxinA 100 U over all comparators for UIE and urgency episodes (credible intervals excluded zero) and all but two of the comparators for micturition frequency. OnabotulinumtoxinA 100 U was also associated with higher odds of achieving a 100% and ≥50% decrease in UIE/day than most other licensed treatments in the network. The exclusion of studies with a high risk of bias had little impact on the conclusions.

Conclusion

The results indicate that, after 12 weeks, onabotulinumtoxinA 100 U provides greater relief of OAB symptoms compared with most other licensed doses of other pharmacotherapies in the network.
Robotic radical perineal cystectomy and extended pelvic lymphadenectomy: initial investigation using a purpose‐built single‐port robotic system
Authors: Maurice Matthew J. , Kaouk Jihad H.
Published: July 2017

Objectives

To assess the feasibility of radical perineal cystoprostatectomy using the latest generation purpose‐built single‐port robotic surgical system.

Materials and Methods

In two male cadavers the da Vinci® SP1098 Surgical System (Intuitive Surgical, Sunnyvale, CA, USA) was used to perform radical perineal cystoprostatectomy and bilateral extended pelvic lymph node dissection (ePLND). New features in this model include enhanced high‐definition three‐dimensional optics, improved instrument manoeuvrability, and a real‐time instrument tracking and guidance system. The surgery was accomplished through a 3‐cm perineal incision via a novel robotic single‐port system, which accommodates three double‐jointed articulating robotic instruments, an articulating camera, and an accessory laparoscopic instrument. The primary outcomes were technical feasibility, intraoperative complications, and total robotic operative time.

Results

The cases were completed successfully without conversion. There were no accidental punctures or lacerations. The robotic operative times were 197 and 202 min.

Conclusions

In this preclinical model, robotic radical perineal cystoprostatectomy and ePLND was feasible using the SP1098 robotic platform. Further investigation is needed to assess the feasibility of urinary diversion using this novel approach and new technology.
Does sex matter? Gender‐specific responses to forest fragmentation in Neotropical bats
Authors: Rocha Ricardo , Ferreira Diogo F. , López‐Baucells Adrià , Farneda Fábio Z. , Carreiras João M. B. , Palmeirim Jorge M. , Meyer Christoph F. J.
Published: July 2017

Understanding the consequences of habitat modification on wildlife communities is central to the development of conservation strategies. However, albeit male and female individuals of numerous species are known to exhibit differences in habitat use, sex‐specific responses to habitat modification remain little explored. Here, we used a landscape‐scale fragmentation experiment to assess, separately for males and females, the effects of fragmentation on the abundance of Carollia perspicillata and Rhinophylla pumilio, two widespread Neotropical frugivorous bats. We predicted that sex‐specific responses would arise from higher energetic requirements from pregnancy and lactation in females. Analyses were conducted independently for each season, and we further investigated the joint responses to local and landscape‐scale metrics of habitat quality, composition, and configuration. Although males and females responded similarly to a fragmentation gradient composed by continuous forest, fragment interiors, edges, and matrix habitats, we found marked differences between sexes in habitat use for at least one of the seasons. Whereas the sex ratio varied little in continuous forest and fragment interiors, females were found to be more abundant than males in edge and matrix habitats. This difference was more prominent in the dry season, the reproductive season of both species. For both species, abundance responses to local‐ and landscape‐scale predictors differed between sexes and again, differences were more pronounced in the dry season. The results suggest considerable sex‐mediated responses to forest disruption and degradation in tropical bats and complement our understanding of the impacts of fragmentation on tropical forest vertebrate communities.
Dental caries clusters among adolescents
Authors: Warren John J. , Van Buren John M. , Levy Steven M. , Marshall Teresa A. , Cavanaugh Joseph E. , Curtis Alexandra M. , Kolker Justine L. , Weber‐Gasparoni Karin
Published: July 2017

Objectives

There have been very few longitudinal studies of dental caries in adolescents, and little study of the caries risk factors in this age group. The purpose of this study was to describe different caries trajectories and associated risk factors among members of the Iowa Fluoride Study (IFS) cohort.

Methods

The IFS recruited a birth cohort from 1992 to 1995, and has gathered dietary, fluoride and behavioural data at least twice yearly since recruitment. Examinations for dental caries were completed when participants were ages 5, 9, 13 and 17 years. For this study, only participants with decayed and filled surface (DFS) caries data at ages 9, 13 and 17 were included (N=396). The individual DFS counts at age 13 and the DFS increment from 13 to 17 were used to identify distinct caries trajectories using Ward's hierarchical clustering algorithm. A number of multinomial logistic regression models were developed to predict trajectory membership, using longitudinal dietary, fluoride and demographic/behavioural data from 9 to 17 years. Model selection was based on the akaike information criterion (AIC).

Results

Several different trajectory schemes were considered, and a three‐trajectory scheme—no DFS at age 17 (n=142), low DFS (n=145) and high DFS (n=109)—was chosen to balance sample sizes and interpretability. The model selection process resulted in use of an arithmetic average for dietary variables across the period from 9 to 17 years. The multinomial logistic regression model with the best fit included the variables maternal education level, 100% juice consumption, brushing frequency and sex. Other favoured models also included water and milk consumption and home water fluoride concentration. The high caries cluster was most consistently associated with lower maternal education level, lower 100% juice consumption, lower brushing frequency and being female.

Conclusions

The use of a clustering algorithm and use of Akaike's Information Criterion (AIC) to determine the best representation of the data were useful means in presenting longitudinal caries data. Findings suggest that high caries incidence in adolescence is associated with lower maternal educational level, less frequent tooth brushing, lower 100% juice consumption and being female.
‘Blue bubble’ technique: an ab interno approach for Descemet separation in deep anterior lamellar keratoplasty using trypan blue stained viscoelastic device
Authors: Livny Eitan , Bahar Irit , Hammel Naama , Nahum Yoav
Published: July 2017

Background

In this study, we examined a novel variant of ‘big‐bubble’ deep anterior lamellar keratoplasty using trypan‐blue‐stained viscoelastic device for the creation of a pre‐descemetic bubble.

Methods

Ten corneoscleral rims were mounted on an artificial anterior chamber (AC). The AC was filled with air through a limbal paracentesis. A Melles' triangulated spatula was inserted through the paracentesis, with its tip penetrating the AC, was then slightly retracted and pushed into the deep stroma above the roof of the paracentesis. A mixture of trypan blue and viscoelastic device (Healon, Abbott Medical Optics, Abbott Park, Illinois) was injected into this intra‐stromal pocket using a 27‐G cannula to create a pre‐descemetic separation bubble. Bubble type and visualization of dyed viscoelastic device were noted. The method was later employed in three cases.

Results

In all 10 corneoscleral rims, the technique successfully created a visible pre‐descemetic (type 1) bubble that could be expanded up to the predicted diameter of trephination. Subsequent trephination and the removal of corneal stroma were uneventful. In two out of four clinical cases, a type 1 bubble was created, while in two others, visco‐dissection failed and dyed viscoelastic was seen in the AC.

Conclusions

The presented technique holds promise of being a relatively easy to perform, predictable and well‐controlled alternative for achieving a type 1 bubble during deep anterior lamellar keratoplasty surgery. The trypan‐blue‐stained viscoelastic device facilitates proper visualization and control of the separation bubble and assists in identifying the penetrance to the separation bubble prior to removal of the stromal cap.