bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation and strategic group dynamics of the Nigerian telecommunications industry
Authors: Oladipo Adejuwon Olawale
Published: June 2014

Purpose

– In order to achieve a desirable level of market efficiency, regulators need to identify the strategic groups within an industry and understand the way the constituent groups relate to one another. The paper aims to discuss these issues.

Design/methodology/approach

– In the current study, factors that may lead to strategic group formation were developed and used as clustering variables in ak-means cluster statistical analysis to categorize the firms into strategic groups. The factors used are entry costs, timing of entry, technology type and scope of operations. In addition, the number and type of competitive actions employed by the firms in the industry were identified by structured content analysis of a public source. The competitive actions were used to examine the dynamics of the resulting groups within the context of competitive behavior, resource and scope commitments and corporate social responsibility (CSR) actions. In addition,χ2 analysis was employed to ascertain the likelihood that actions of a firm will be responded to by firms from the same group or from outside the group.

Findings

– License fees was found to be the most significant clustering variable. The study also showed that groups with significantly higher license fees carried out considerably more competitive actions, had higher resource and scope commitments and executed more CSR actions. In addition, the study revealed significantly more competition within strategic groups than between groups.

Research limitations/implications

– The absence of financial records for firms in the sample necessitated the use of CSR activity as a measure of firm performance. Some empirical studies have shown strong links between CSR and firm performance.

Practical implications

– The study revealed high mobility barriers which prevent ease of movement of firms in the industry from one strategic group to the other. Therefore regulators who wish to promote competition must do so by identifying the strategic groups with significant market power and permitting entry not by lowering entry barriers but by allowing the entry of firms with proven resources similar to the firms in those groups and to stipulate similar commitments in entry conditions. The results also offer management practitioners an insight into competitive behavior in the industry.

Originality/value

– The study utilized a unique data set (competitive actions of firms in the Nigerian Telecommunications industry as reported in the media) in contributing to empirical studies on competitive dynamics and strategic group literature.
Personality traits and simultaneous reciprocal influences between job performance and job satisfaction
Authors: Yang Cheng-Liang , Hwang Mark
Published: June 2014

Purpose

– This paper aims to test the relationships among three important variables in the management of Chinese employees: personality trait, job performance and job satisfaction. A causal model is developed to hypothesize how personality trait affects job performance and satisfaction and how job performance and satisfaction simultaneously affect each other.

Design/methodology/approach

– The survey was conducted from October to November 2009. In total, 414 questionnaires were distributed and 392 were returned. Using data collected, the theoretical model is empirically validated. Structural equation modelling using LISREL 8.8 is used to test the causal model.

Findings

– Job performance and job satisfaction have a bilateral relationship that is simultaneously influential. All Big Five personality traits significantly influence job performance, with agreeableness showing the greatest effect, followed by extraversion. Extraversion is the only personality trait that shows a significant influence over job satisfaction.

Originality/value

– This study contributes to the literature by clarifying the inconsistent findings of causal relationship between job performance and job satisfaction in previous studies. Another contribution is testing the effect of personality traits on job performance and job satisfaction in a simultaneous reciprocal model. A hybrid theory of expectance and equity is advanced in this study to explain the results.
Relationship between employees’ performance and social network structure
Authors: Cai Meng , Du Haifeng , Zhao Chen , Du Wei
Published: June 2014

Purpose

– The aim of this paper, considering the two types of networks and the scope of power from structural holes, is to clarify the relationship between employees’ performance and their social network structure in Chinese small and medium enterprises from the whole-network perspective. The complicated relationship in Chinese culture requires human resource management (HRM) practitioners to be aware of the implications of social network.

Design/methodology/approach

– An empirical research approach is used in this paper. Using the cluster sampling method, authors collected 118 employees’ characteristic data and network data by face-to-face interviews through structured questionnaire survey, and also got their performance data from the financial department, which support correlation analysis and OLS regression analysis.

Findings

– First, informal network, but not formal network, has a significant impact on employees’ performance. Second, individual performance of brokerage is greater for direct than indirect contacts. Finally, broker-of-brokers will be the winner in the competition.

Originality/value

– First, previous research focuses on egocentric network as the difficulty of data collection, while this paper analyzes a whole network based on the real social network. Second, this paper reveals the network structure mode where individuals get benefits. Third, it also uncovers the effect of relationship type on employees’ performance in Chinese SME. Finally, this paper identifies the status homophily and status crystallization phenomenon in the process of social network formation.
Prediction of convective heat transfer of Al2O3-water nanofluid considering particle migration using neural network
Authors: Bahiraei Mehdi , Mostafa Hosseinalipour Seyed , Hangi Morteza
Published: June 2014

Purpose

– The purpose of this paper is to attempt to investigate the particle migration effects on nanofluid heat transfer considering Brownian and thermophoretic forces. It also tries to develop a model for prediction of the convective heat transfer coefficient.

Design/methodology/approach

– A modified form of the single-phase approach was used in which an equation for mass conservation of particles, proposed by Buongiorno, has been added to the other conservation equations. Due to the importance of temperature in particle migration, temperature-dependent properties were applied. In addition, neural network was used to predict the convective heat transfer coefficient.

Findings

– At greater volume fractions, the effect of wall heat flux change was more significant on nanofluid heat transfer coefficient, whereas this effect decreased at higher Reynolds numbers. The average convective heat transfer coefficient raised by increasing the Reynolds number and volume fraction. Considering the particle migration effects, higher heat transfer coefficient was obtained and also the concentration at the tube center was higher in comparison with the wall vicinity. Furthermore, the proposed neural network model predicted the heat transfer coefficient with great accuracy.

Originality/value

– A review of the literature shows that in the single-phase approach, uniform concentration distribution has been used and the effects of particle migration have not been considered. In this study, nanofluid heat transfer was simulated by adding an equation to the conservation equations to consider particle migration. The effects of Brownian and thermophoretic forces have been considered in the energy equation. Moreover, a model is proposed for prediction of convective heat transfer coefficient.
Does employee-perceived reputation contribute to citizenship behavior?
Authors: Fu Hui , Li Yaoqi , Duan Yanhong
Published: June 2014

Purpose

– The purpose of this study is to propose and verify a research model that investigates the mediating role of organizational commitment on the relationship between hotel employee-perceived reputation and organizational citizenship behaviors (OCBs).

Design/methodology/approach

– Based on the data obtained from a sample of 323 hotel employees in China, the reliability, validity and hypothesized relationships in the model were tested through structural equation modeling using LISREL 8.70.

Findings

– Empirical results show that different dimensions of corporate reputation affect OCBs differently. Social responsibility reputation has both direct and indirect effects on OCBs, while there is no direct link between employee-treatment reputation and OCBs. The relationship between corporate reputation and OCBs is mediated by organizational commitment.

Practical implications

– Hotel managers should pay more attention to employee perception of the hotel’s reputation. Reputation management is as important as reputation building. Favorable perception of hotel’s reputation contributes to positive behavioral intentions.

Originality/value

– Most recent research has explored the relationship between corporate reputation and customer behaviors. However, few studies take employee perception of reputation into consideration. This study tried to fill this void. Also, this study contributes to the current knowledge of both the reputation literature and citizenship literature by exploring the mediation of organizational commitment on the relationship between employee-perceived reputation and citizenship behaviors through data obtained from Chinese hotels.
Do affluent customers care when luxury brands go mass?
Authors: Yang Wan , S. Mattila Anna
Published: June 2014

Purpose

– This paper aims to examine the joint effects of product type (hospitality services vs goods) and consumers’ need for status (low/Patricians vs high/Parvenus) on consumers’ attitude change toward their favorite luxury brands. As an ever increasing number of customers can now afford luxury products, it is important to understand how affluent consumers react to the less affluent mimicking behaviors.

Design/methodology/approach

– In all, 265 luxury consumers with annual household income of more than $100,000 and experiences of luxury consumption in the past three months were recruited. A 2 (product type) × 2 (need for status) factorial design was used to test the hypotheses.

Findings

– This study demonstrates that when faced with mimicking behaviors by less affluent consumers, Parvenus exhibit more negative attitude toward their favorite luxury goods brands than luxury hospitality brands. Conversely, Patricians exhibit similar levels of attitude change across the two types of luxury brands.

Practical implications

– The findings suggest that luxury hospitality companies may find it easier to expand to less affluent markets than their luxury goods counterparts, in particular when the majority of target consumers are Parvenus.

Originality/value

– To the best of the authors’ knowledge, this study is the first to examine consumers’ reactions to mimicking behaviors by the less affluent in the context of luxury hospitality services, and it adds to the knowledge on the joint effects of product type and status seeking on luxury consumption.
Festival attendees’ motivations: the case of International Troia Festival
Authors: Duran Erol , Hamarat Bahattin
Published: June 2014

Purpose

– The purpose of this paper is to investigate underlying motivational dimensions of visitors attending the International Troia Festival (ITF), Çanakkale, Turkey.

Design/methodology/approach

– Surveys with 26 items on six motivational dimensions were empirically tested. Data were collected by a self-administered survey. The study sample comprised attendees of particular festival events which were suitable for survey practice in the ITF lasting for five days. The participants of the survey were the attendees of two theater shows, two conferences, and two folk dance shows. A total of 473 usable forms were obtained from the visitors and processed in the analysis.

Findings

– Significant differences and relations in motivational dimensions were found on the basis of visitors’ socio-demographic origins. Female visitors are more likely to attend festival events with high motivation of family togetherness and cultural exploration. Also male visitors are more likely to attend the events with more motivation of event attraction and escape and excitement than family togetherness. Motivation of cultural exploration is also high for all socio-demographic groups of festival visitors. Thereby, cultural exploration and family togetherness are also highly important for attendees. The basic theme of the ITF was identified as a cultural festival which essentially motivates visitors to attend particularly for cultural exploration.

Research limitations/implications

– The findings of this paper solely reflect the motivational dimensions identified during a Turkish festival with a cultural lifestyle.

Practical implications

– The field research of the study demonstrates the application of methodology by event managers to gain better understanding into visitor motivation, satisfaction, behavioral intention, event organization, and event theme.

Originality/value

– The important theoretical contribution of the study is in the area of establishing a meaningful and empirical relation between motivation of festivals and cultural structure of community as part of the perceived socio-cultural impacts of festivals. This implies and empirically substantiates the common belief that festivals and events can be instrumental in enriching cultural life.
Using a multiple-informant approach in SCM research
Authors: Kaufmann Lutz , Astou Saw Aischa
Published: June 2014

Purpose

– The purpose of this paper is to review the current state of survey-based SCM research that employs a multiple-informant perspective. Recommendations on how to rigorously conduct such research are developed, strengths and limitations discussed, and opportunities for advancing the discipline through this approach identified.

Design/methodology/approach

– A systematic literature review (SLR) of 1,048 articles published in five leading SCM journals within a seven-year time frame is conducted.

Findings

– The review shows that multiple-informant studies are still largely under-represented. Yet this approach more accurately depicts the multi-faceted nature of SCM. Specific requirements of this approach need to be considered throughout the research process, from unit of analysis, sampling frame, and data collection to analytic strategy.

Research limitations/implications

– Taking into account the often complex, dynamic actor networks in which SCM phenomena are embedded may provide new insights, especially when controversial results have been found. This approach may also enrich the understanding of phenomena that have previously been examined only from a monadic perspective.

Originality/value

– The paper examines the low incidence of multiple-informant survey research in SCM, discusses how its application can advance the field, and provides guidance on how to effectively apply this approach to more fully understand complex SCM phenomena. It further shows that studies using multiple informants yield novel theoretical insights and valuable recommendations for decision makers on how to use the interfaces between different actors across functional and organizational borders.
To explore new avenues: experiential testimonio research
Authors: Albert Marie-Noelle , Couture Marie-Michele
Published: June 2014

Purpose

– The purpose of this paper is to propose a qualitative research method for which the empirical material is drawn from the experience of a practitioner-researcher.

Design/methodology/approach

– First, a review of other autobiographical methods is made to show that the proposed method offers something different. Subsequently, it briefly outlines the epistemological and theoretical anchors that guided the development of the proposed method. Then it follows the path and the peculiarities of this method. And finally a few guidelines are presented for the legitimization of the knowledge generated, illustrated by an example.

Findings

– The proposed method is aimed at experienced practitioners who are involved in a process of scientific research. Ideally, it is carried out with a co-searcher.

Originality/value

– A new method of qualitative research to explore new avenues in management science.
Appropriation or participation of the individual in knowledge management
Authors: D.W. Rechberg Isabel , Syed Jawad
Published: June 2014

Purpose

– The purpose of this paper is to examine whether there is a tendency towards appropriation or participation of the individual in the literature of knowledge management (KM).

Design/methodology/approach

– This is a literature review paper. In terms of approach, appropriation in this paper is referred to as the KM tasks assigned to individual employees by the management whereas participation is referred to as KM tasks determined jointly by individuals and management.

Findings

– The review suggests that while the participation of individuals is seen as important for KM, the KM discourse is visibly oriented towards the appropriation of individual employees and their knowledge for better economic performance of organisations. The review suggests that an appropriation of the individual in KM serves neither employees nor organisations, and that individual employees are meant to be valued participants in the development and management of knowledge.

Research limitations/implications

– The paper is concerned with the KM literature to study the appropriation or participation of individual employees in the discourse on KM. Consequently other streams of literature that address individual employees’ participation are excluded from this study.

Originality/value

– The paper initiates a new research agenda for KM where the emphasis shifts from the appropriation to the participation of the individual in the discourse on KM practices.
The use of strong and weak form sustainability to assist in rate development for the valuation of exhaustible resources (part I)
Authors: Grissom T.V. , McCord M. , McIlhatton D. , Haran M.
Published: June 2014

Purpose

– The purpose of this paper, which is the first of a two-part series, is to build upon the established research on environmental economics and sustainability theory developed by Ramsey (1928), Weitzman (2007) and Gollier (2010). The Ramsey-Weitzman-Gollier model, with the contribution of Howarth (2009) and Nordhaus (2007a, b), focuses on discount rate development for environmental and long-term assets, linking discounted utility analysis embedded in the CCAPM model of Lucas (1978) to the policy concerns associated with the valuation of public and sustainable resources. This paper further investigates these issues to the rates structure appropriate for exhaustible resources with a particular emphasis on urban land, based upon the differentiation of strong and weak form sustainability concepts constrained by the objectives of the sustainable criterion of Daly and Cobb (1994).

Design/methodology/approach

– The paper integrates the concepts of discount rate development for environmental and long-term assets and discounted utility analysis to the policy concerns associated with the valuation of public and sustainable resources. It develops new theoretical insight in order to allow the theoretical formulation of discount and capitalization rates that can be empirically applied and tested.

Findings

– The paper provides theoretical support for a new approach concerned with the development of capitalization and discount rates in the valuation of non-renewable resources. A key concern of valuing non-renewable or limited resource endowments (in space or time) is the problem of irreversible investment or irrevocable decision implementation as suggested by Arrow-Fisher (1974), Krautkraemer (1985) and Daly and Cobb (1994). It investigates the challenge with developing capitalization rates and valuation of depleting resources temporally, within the constraints of sustainability. To achieve this, an optimal control discounting procedure subject to a sustainable objective statement is employed – in this context it suggests that sustainability should be treated as an alternative to traditional growth and the maximization of near-term returns.

Originality/value

– This paper extends the construct of developing rates structures appropriate for the valuation of exhaustible resources. It places a conceptual emphasis on urban land development. The measures developed and the insights gained may serve as a basis for future research on the optimal levels of sustainable development appropriate for different nations.
Social media for developing health services
Authors: Bugshan Hatem , Nick Hajli M. , Lin Xiaolin , Featherman Mauricio , Cohen Ivan
Published: June 2014

Purpose

– The purpose of this paper is to explore in depth how Web 2.0 (focusing on social media) contributes to create a better communication channel to provide information, support and assistance to patients. Social relationships of individuals on the Internet through social media have created added value for many industries. This phenomenon can be an opportunity for the health care industry, which has encountered huge challenges such as increasing demands, budget cuts, growing numbers of patients and more demanding patient expectations. Web 2.0 and social media have the potential value to make possible an increase in the productivity of modern health care and a reduction in cost to the central government. Social media introduces better channels of communication with patients to increase the value of e-health. Social media are building more social communities that empower patients to share their personalized health information and treatments.

Design/methodology/approach

– Grounded on social support and transaction cost theories, this paper evaluates the current potential of social media to discuss values it can offer for the overall benefit of the health care industry.

Findings

– The results show how the social relationship of individuals provides online social support and reduction of cost through social media, leading to the development of modern health care. Implications and limitations are discussed at the end of the paper.

Originality/value

– The analysis results indicated that social media provides strong social support for patients who seek help online. Informational support and emotional support have been confirmed as two main dimensions of social support in online health care. It makes a contribution to the health care literature by extending it to online health care support in the context of social media. It may inform and provide some initial understanding to guide future research. In addition, this study indicates that social support theory and transaction cost are appropriate theoretical foundations for studies of online health care. This finding is very valuable, as it helps researchers to advance the understanding of how social media support online health care.
Species undersampling in tropical bat surveys: effects on emerging biodiversity patterns
Authors: Meyer Christoph F. J. , Aguiar Ludmilla M. S. , Aguirre Luis F. , Baumgarten Julio , Clarke Frank M. , Cosson Jean‐François , Estrada Villegas Sergio , Fahr Jakob , Faria Deborah , Furey Neil , Henry Mickaël , Jenkins Richard K. B. , Kunz Thomas H. , Cristina MacSwiney González M. , Moya Isabel , Pons Jean‐Marc , Racey Paul A. , Rex Katja , Sampaio Erica M. , Stoner Kathryn E. , Voigt Christian C. , von Staden Dietrich , Weise Christa D. , Kalko Elisabeth K. V.
Published: June 2014

Undersampling is commonplace in biodiversity surveys of species‐rich tropical assemblages in which rare taxa abound, with possible repercussions for our ability to implement surveys and monitoring programmes in a cost‐effective way.

We investigated the consequences of information loss due to species undersampling (missing subsets of species from the full species pool) in tropical bat surveys for the emerging patterns of species richness (SR) and compositional variation across sites.

For 27 bat assemblage data sets from across the tropics, we used correlations between original data sets and subsets with different numbers of species deleted either at random, or according to their rarity in the assemblage, to assess to what extent patterns in SR and composition in data subsets are congruent with those in the initial data set. We then examined to what degree high sample representativeness (r ≥ 0·8) was influenced by biogeographic region, sampling method, sampling effort or structural assemblage characteristics.

For SR, correlations between random subsets and original data sets were strong (r ≥ 0·8) with moderate (ca. 20%) species loss. Bias associated with information loss was greater for species composition; on average ca. 90% of species in random subsets had to be retained to adequately capture among‐site variation. For nonrandom subsets, removing only the rarest species (on average c. 10% of the full data set) yielded strong correlations (r > 0·95) for both SR and composition. Eliminating greater proportions of rare species resulted in weaker correlations and large variation in the magnitude of observed correlations among data sets.

Species subsets that comprised ca. 85% of the original set can be considered reliable surrogates, capable of adequately revealing patterns of SR and temporal or spatial turnover in many tropical bat assemblages. Our analyses thus demonstrate the potential as well as limitations for reducing survey effort and streamlining sampling protocols, and consequently for increasing the cost‐effectiveness in tropical bat surveys or monitoring programmes. The dependence of the performance of species subsets on structural assemblage characteristics (total assemblage abundance, proportion of rare species), however, underscores the importance of adaptive monitoring schemes and of establishing surrogate performance on a site by site basis based on pilot surveys.
Life‐history trade‐offs mediate ‘personality’ variation in two colour morphs of the pea aphid,Acyrthosiphon pisum
Authors: Schuett Wiebke , Dall Sasha R. X. , Kloesener Michaela H. , Baeumer Jana , Beinlich Felix , Eggers Till
Published: June 2014

Life‐history trade‐offs are considered a major driving force in the emergence of consistent behavioural differences (personality variation); but empirical tests are scarce.

We investigated links between a personality trait (escape response), life‐history and state variables (growth rate, size and age at first reproduction, age‐dependent reproductive rates, lifetime reproductive success, life span) in red and green colour morphs of clonal pea aphids,Acyrthosiphon pisum. Escape response (dropping/non‐dropping off a plant upon a predatory attack) was measured repeatedly to classify individuals as consistent droppers, consistent nondroppers or inconsistents.

Red morphs experienced stronger trade‐offs between early reproduction and life span than green morphs; and red consistent (non)droppers had highest lifetime reproductive success. Red droppers followed a risk‐averse life‐history strategy (high late reproduction), red nondroppers a risk‐prone strategy (high early reproduction), while reproductive rates were equivalent for all green behavioural types and red inconsistents.

This suggests that red morphs suffer the highest costs of dropping (they are most conspicuous to predators), which ‘equivalates’ fitness payoffs to both risk‐takers (red non‐droppers) and risk‐averse red droppers. The strong trade‐off also means that committing to a particular lifestyle (being consistent) maximises fitness.

Our study suggests that life‐history trade‐offs likely mediate personality variation but effects might depend on interactions with other organismal characteristics (here: colour morph).
A better IDEA: best practice and outcomes‐oriented remedies in public impact litigation for students with disabilities
Authors: Noonan Kathleen G. , McCarthy Megan A. , Shea Lindsay , Marcus Steven C. , Mandell David S.
Published: June 2014

Class action lawsuits filed in violation of Individuals with Disabilities Education Act (IDEA) raise questions for those concerned with improving the education system for students with disabilities. First, do the lawsuits result in changes that can be directly linked to improved student outcomes? Second, do these lawsuits and the ‘consent decrees’ that settle them refer to best practices in educating children with disabilities? To date, no study has examined the remedies ordered as a result of these lawsuits in the disability education context, or proven how different types of remedies can impede or facilitate progress for students with disabilities. Class action lawsuits under IDEA filed in large, urban school districts between 1990 and 2011 and the remedies ordered under the final agreement were reviewed. This review suggests that the lawsuits against large, urban school districts tend to result in remedial activities that focus more on planning, supporting and monitoring than on outcomes or evidence‐based practice.
Institute of Food Technologists (IFT) Education Division Competition 2013 Winner‐A Consumer's Guide to Probiotics: A Glimpse into the Big Picture of a Microscopic World
Authors: Reed Spenser
Published: June 2014

One of the core competencies in the Institute of Food Technologists (IFT) education standards is for students to achieve competency in communication skills (that is, oral and written communication, listening, interviewing, and so on). According to the IFT guidelines, by the time students graduate, they should not only be able to search for and condense information, but also be able to “communicate technical information to a nontechnical audience.” The Education Division of IFT sponsors a writing competition for undergraduate students to bring attention to and promote the development of communication skills. It has been shown that employees/entry‐level scientists who can communicate technical and nontechnical concepts succinctly will be in a better position to achieve management status after entering the work force. Monetary prizes are awarded to the authors of the top three papers. A revised version of the winning entry is published in the Journal of Food Science Education for dissemination to a world‐wide audience.
The high molecular weight glutenin subunit Bx7 allergen from wheat contains repetitive IgE epitopes
Authors: Baar A. , Pahr S. , Constantin C. , Giavi S. , Papadopoulos N. G. , Pelkonen A. S. , Mäkelä M. J. , Scheiblhofer S. , Thalhamer J. , Weber M. , Ebner C. , Mari A. , Vrtala S. , Valenta R.
Published: June 2014

Background

Wheat is one of the most common food allergen sources for children and adults. The aim of this study was to characterize new wheat allergens using an IgE discovery approach and to investigate their IgE epitopes.

Methods

A cDNA expression library representing the wheat transcriptome was constructed in phage lambda gt11 and screened with IgE antibodies from wheat food allergic patients. IgE‐reactive cDNA clones coding for portions of high molecular weight (HMW) glutenin subunits were identified by sequence analysis of positive clones. IgE epitopes were characterized using recombinant fragments from the HMW Bx7 and synthetic peptides thereof for testing of allergic patients' sera and in basophil degranulation assays.

Results

We found that the major IgE‐reactive areas of HMW glutenins are located in the repetitive regions of the protein and could show that two independent IgE‐reactive fragments from HMW Bx7 contained repetitive IgE epitopes.

Conclusions

Our results demonstrate that IgE antibodies from wheat food allergic patients can recognize repetitive epitopes in one of the important wheat food allergens. Recombinant HMW Bx7 may be included into the panel of allergens for component‐resolved diagnosis of wheat food allergy.
Systematic review with meta‐analysis: alcohol consumption and the risk of colorectal adenoma
Authors: Zhu J.‐Z. , Wang Y.‐M. , Zhou Q.‐Y. , Zhu K.‐F. , Yu C.‐H. , Li Y.‐M.
Published: June 2014

Background

Studies on the relation between alcohol consumption and risk of colorectal adenoma (CRA), a precursor of colorectal cancer, have been inconsistent.

Aim

A systematic review with meta‐analysis was conducted to investigate the association and the dose–response of alcohol with CRA.

Methods

A literature search was performed on PubMed to identify relevant studies published up to January 2014. A fixed or random effects model was used to estimate summarised relative risks (RRs) and 95% confidence intervals (CIs) for the association between alcohol intake and CRA risk. Statistical heterogeneity between studies was assessed with the χ2 statistic and quantified by I².

Results

Twenty‐three case–control studies and two cohort studies were included in the meta‐analysis. All drinkers were associated with 17% increased risk for CRA, compared with nondrinkers or occasional alcohol drinkers. The dose–response analysis demonstrated that for drinkers of 10, 25, 50 and 100 g/day alcohol consumption, the estimated RRs of CRA were 1.02 (95% CI 0.89–1.16), 1.06 (95% CI 0.92–1.20), 1.16 (95% CI 1.02–1.33) and 1.61 (95% CI 1.42–1.84) respectively, in comparison with non‐/occasional drinkers. The risks were consistent in the subgroup analyses of gender and site of adenoma, while it was stronger in European studies than the studies in the US and Asia.

Conclusions

This study suggests that alcohol intake is related to a significant increase of risk for colrectal adenoma.
Serotonergic reinforcement of intestinal barrier function is impaired in irritable bowel syndrome
Authors: Keszthelyi D. , Troost F. J. , Jonkers D. M. , van Eijk H. M. , Lindsey P. J. , Dekker J. , Buurman W. A. , Masclee A. A. M.
Published: June 2014

Background

Alterations in serotonergic (5‐HT) metabolism and/or intestinal integrity have been associated with irritable bowel syndrome (IBS).

Aims

To assess the effects of the precursor of 5‐HT, 5‐hydroxytryptophan (5‐HTP), on mucosal 5‐HTavailability and intestinal integrity, and to assess potential differences between healthy controls andIBSpatients.

Methods

FifteenIBSpatients and 15 healthy volunteers participated in this randomised double‐blind placebo‐controlled study. Intestinal integrity was assessed by dual‐sugar test and by determining the mucosal expression of tight junction proteins after ingestion of an oral bolus of 100 mg 5‐HTPor placebo. Mucosal serotonergic metabolism was assessed in duodenal biopsy samples.

Results

5‐HTPadministration significantly increased mucosal levels of 5‐HIAA, the main metabolite of 5‐HT, in both healthy controls (7.1 ± 1.7 vs. 2.5 ± 0.7 pmol/mg, 5‐HTPvs. placebo,P = 0.02) andIBSpatients (20.0 ± 4.8 vs. 8.1 ± 1.3 pmol/mg, 5‐HTPvs. placebo,P = 0.02), with the latter group showing a significantly larger increase. Lactulose/L‐rhamnose ratios were significantly lower after administration of 5‐HTP(P < 0.05) in healthy controls and were accompanied by redistribution of zonula occludens‐1 (ZO‐1), pointing to reinforcement of the barrier. InIBS, expression of the tight junction proteins was significantly lower compared to healthy controls, and 5‐HTPresulted in a further decrease in occludin expression.

Conclusions

Oral 5‐HTPinduced alterations in mucosal 5‐HTmetabolism. In healthy controls, a reinforcement of the intestinal barrier was seen whereas such reaction was absent inIBSpatients. This could indicate the presence of a serotonin‐mediated mechanism aimed to reinforce intestinal barrier function, which seems to dysfunction inIBSpatients.
Mortality after total colectomy in 3084 patients with inflammatory bowel disease: a population‐based cohort study
Authors: Nordenvall C. , Ekbom A. , Bottai M. , Smedby K. E. , Nilsson P. J.
Published: June 2014

Background

A high post‐operative mortality has been reported following colectomy in patients with inflammatory bowel disease (IBD), especially in some patient groups.

Aims

To investigate the 40‐day mortality following colectomy in patients with IBD. The secondary aim was to assess whether colectomised IBD patients have an increased mortality compared to the general population.

Methods

This is a population‐based register study of all patients with IBD in Sweden who underwent total colectomy in 2000–2010. The cohort was identified using international classification codes for ulcerative colitis (UC) and Crohn's disease (CD). Patients registered with both UC and CD before colectomy (UCCD) were analysed separately. Each patient was followed‐up to the date of death, migration or 31st of December 2010, whichever came first. Kaplan–Meier survival curves, Cox proportional hazards models and relative mortality rates were used to describe mortality.

Results

In the cohort of 3084 patients, 2424 were diagnosed with UC, 326 with CD and 334 with UCCD. The 40‐day, 1‐year and 3‐year mortality was 1.3%, 3.1% and 6.0%, respectively. The highest 40‐day mortality was seen in patients ≥59 years of age (4.4%). Colectomy at the primary hospitalisation for IBD did not significantly increase the risk of post‐operative mortality, nor did hospital volume. The relative survival after 3 years was 0.99, 0.98, 0.97 and 0.90 in those <30, 30–43, 44–58 and ≥59 years old, respectively.

Conclusion

The 40‐day mortality following total colectomy in IBD patients in Sweden is low, except in patients ≥59 years old.
Efficient pairwise composite likelihood estimation for spatial‐clustered data
Authors: Bai Yun , Kang Jian , Song Peter X.‐K.
Published: June 2014

Spatial‐clustered data refer to high‐dimensional correlated measurements collected from units or subjects that are spatially clustered. Such data arise frequently from studies in social and health sciences. We propose a unified modeling framework, termed as GeoCopula, to characterize both large‐scale variation, and small‐scale variation for various data types, including continuous data, binary data, and count data as special cases. To overcome challenges in the estimation and inference for the model parameters, we propose an efficient composite likelihood approach in that the estimation efficiency is resulted from a construction of over‐identified joint composite estimating equations. Consequently, the statistical theory for the proposed estimation is developed by extending the classical theory of the generalized method of moments. A clear advantage of the proposed estimation method is the computation feasibility. We conduct several simulation studies to assess the performance of the proposed models and estimation methods for both Gaussian and binary spatial‐clustered data. Results show a clear improvement on estimation efficiency over the conventional composite likelihood method. An illustrative data example is included to motivate and demonstrate the proposed method.
Academic Medical Product Development: An Emerging Alliance of Technology Transfer Organizations and the CTSA
Authors: Rose Lynn M. , Everts Maaike , Heller Caren , Burke Christine , Hafer Nathaniel , Steele Scott
Published: June 2014

To bring the benefits of science more quickly to patient care, the NIH National Center Advancing Translational Sciences (NCATS) supports programs that enhance the development, testing, and implementation of new medical products and procedures. The NCATS clinical and translational science award (CTSA) program is central to that mission; creating an academic home for clinical and translational science and supporting those involved in the discovery and development of new health‐related inventions. The technology transfer Offices (TTO) of CTSA‐funded universities can be important partners in the development process; facilitating the transfer of medical research to the commercial sector for further development and ultimately, distribution to patients. The Aggregating Intellectual Property (IP) Working Group (AWG) of the CTSA public private partnerships key function committee (PPP‐KFC) developed a survey to explore how CTSA‐funded institutions currently interface with their respective TTOs to support medical product development. The results suggest a range of relationships across institutions; approximately half have formal collaborative programs, but only a few have well‐connected programs. Models of collaborations are described and provided as examples of successful CTSA/TTO partnerships that have increased the value of health‐related inventions as measured by follow‐on funding and industry involvement; either as a consulting partner or licensee.
An unavoidable modulation? Sensory attention and human primary motor cortex excitability
Authors: Ruge Diane , Muggleton Neil , Hoad Damon , Caronni Antonio , Rothwell John C.
Published: June 2014

The link between basic physiology and its modulation by cognitive states, such as attention, is poorly understood. A significant association becomes apparent when patients with movement disorders describe experiences with changing their attention focus and the fundamental effect that this has on their motor symptoms. Moreover, frequently used mental strategies for treating such patients, e.g. with task‐specific dystonia, widely lack laboratory‐based knowledge about physiological mechanisms. In this largely unexplored field, we looked at how the locus of attention, when it changed between internal (locus hand) and external (visual target), influenced excitability in the primary motor cortex (M1) in healthy humans. Intriguingly, both internal and external attention had the capacity to change M1 excitability. Both led to a reduced stimulation‐induced GABA‐related inhibition and a change in motor evoked potential size, i.e. an overall increased M1 excitability. These previously unreported findings indicated: (i) that cognitive state differentially interacted with M1 physiology, (ii) that our view of distraction (attention locus shifted towards external or distant location), which is used as a prevention or management strategy for use‐dependent motor disorders, is too simple and currently unsupported for clinical application, and (iii) the physiological state reached through attention modulation represents an alternative explanation for frequently reported electrophysiology findings in neuropsychiatric disorders, such as an aberrant inhibition.
The cholinergic basal forebrain in the ferret and its inputs to the auditory cortex
Authors: Bajo Victoria M. , Leach Nicholas D. , Cordery Patricia M. , Nodal Fernando R. , King Andrew J.
Published: June 2014

Cholinergic inputs to the auditory cortex can modulate sensory processing and regulate stimulus‐specific plasticity according to the behavioural state of the subject. In order to understand how acetylcholine achieves this, it is essential to elucidate the circuitry by which cholinergic inputs influence the cortex. In this study, we described the distribution of cholinergic neurons in the basal forebrain and their inputs to the auditory cortex of the ferret, a species used increasingly in studies of auditory learning and plasticity. Cholinergic neurons in the basal forebrain, visualized by choline acetyltransferase and p75 neurotrophin receptor immunocytochemistry, were distributed through the medial septum, diagonal band of Broca, and nucleus basalis magnocellularis. Epipial tracer deposits and injections of the immunotoxin ME20.4‐SAP (monoclonal antibody specific for the p75 neurotrophin receptor conjugated to saporin) in the auditory cortex showed that cholinergic inputs originate almost exclusively in the ipsilateral nucleus basalis. Moreover, tracer injections in the nucleus basalis revealed a pattern of labelled fibres and terminal fields that resembled acetylcholinesterase fibre staining in the auditory cortex, with the heaviest labelling in layers II/III and in the infragranular layers. Labelled fibres with small en‐passant varicosities and simple terminal swellings were observed throughout all auditory cortical regions. The widespread distribution of cholinergic inputs from the nucleus basalis to both primary and higher level areas of the auditory cortex suggests that acetylcholine is likely to be involved in modulating many aspects of auditory processing.
A NanoSIMS study on the distribution of soil organic matter, iron and manganese in a nodule from a Stagnosol
Authors: Rennert T. , Händel M. , Höschen C. , Lugmeier J. , Steffens M. , Totsche K. U.
Published: June 2014

The development of Stagnosols is the consequence of perched water tables, which induce periodic oxidizing and reducing conditions. These cause the spatial distribution of iron (Fe) and manganese (Mn) between the soil matrix and ferromanganese concretions or nodules. Since oxides of these metals may interact with organic matter, we studied their spatial distribution in bulk material from the Bg horizon of a Stagnosol and in a nodule separated from the horizon. We used wet‐chemical analyses and X‐ray diffractometry together with microscopic techniques and nano‐scale secondary ion mass spectrometry (NanoSIMS), the latter allowing for a submicrometre‐scale spatial resolution. X‐ray diffractometry revealed the presence of quartz, clay minerals, micas and feldspars as the dominant minerals and indicated the presence of lepidocrocite. Relative to the bulk horizon material, the nodule was strongly enriched in organic C (by a factor of 31) and pedogenic (dithionite‐extractable) Fe and Mn (by factors of 2.2 and 62). We selected two regions on a thin section of the nodule for NanoSIMS investigations after studying the element distribution by scanning‐electron microscopy (SEM): one was located in an almost closed pore, the other one along an elongated pore. The NanoSIMS measurements allowed a clearer distinction of Fe‐ and Mn‐accumulation zones than SEM‐EDS. The evaluation of the NanoSIMS measurements by unsupervised classification revealed that zones containing silicates and Mn oxides and the transitional zones between Fe and Mn oxides were particularly enriched in soil organic matter, while, with one exception, the pure Fe‐accumulation zones did not indicate the presence of soil organic matter.
Loss of cerebral white matter in primary Sjögren's syndrome: a controlled volumetric magnetic resonance imaging study
Authors: Lauvsnes M. B. , Beyer M. K. , Appenzeller S. , Greve O. J. , Harboe E. , Gøransson L. G. , Tjensvoll A. B. , Omdal R.
Published: June 2014

Background and purpose

Although brain involvement is common in primary Sjögren's syndrome (pSS), results from cerebral imaging studies are inconsistent. This study aimed to perform both voxel‐wise and global brain volume analyses in a nearly population‐based pSS cohort to explore whether the patients displayed any focal or diffuse volume differences compared with healthy subjects.

Methods

Global grey matter (GM) and white matter (WM) volumes were measured and compared in 60 patients with pSS and 60 age‐ and gender‐matched healthy subjects. Regression models were constructed with potential explanatory variables for GM and WM volumes. In the same groups, voxel‐wise morphometric analyses were performed.

Results

In analyses of global GM and WM, the patients had lower WM volumes than healthy subjects (540 ± 63 cm3 vs. 564 ± 56 cm3, P = 0.02), but no differences in GM. Voxel‐wise analyses displayed no localized areas of GM or WM volume differences between pSS patients and healthy subjects.

Conclusion

Individuals with pSS have a diffuse reduction of cerebral WM but no localized loss of WM or GM. This indicates a general deleterious effect on WM due to pSS itself.