bluuebunny/crossref_metadata_2025 huggingface dataset:
Well integrity assessment for CO2 injection
Authors: Asamoto Shingo , Le Guen Yvi , Poupard Olivier , Capra Bruno
Published: August 2013

Purpose

In the carbon dioxide capture and storage (CCS) project, the integrity of CO2 injection wells plays a vital role in the long‐term safety of CO2 storage. The authors aim to practically investigate possible CO2 leakage of a CO2 injection well section during the injection operation and shut‐in by the thermomechanical FEM simulation. The application of numerical simulation to the CO2 injection well deep underground is the first step that will help in the quantitative evaluation of the mechanical risks.

Design/methodology/approach

The injection of CO2 at a temperature different from those of the well and the surrounding geological formation is likely to cause different thermal deformations of constitutive well materials. This could lead to cement cracking and microannuli openings at the interfaces of different materials such as casing/cement and cement/rock. In this paper, the possibility and order of magnitude of cement cracking and microannuli creation in the cross section of the well are assessed from a numerical case study within a classical thermomechanical finite element model framework.

Findings

The possibility of compressive failure and tensile cracking in the cement of the studied wells due to CO2 injection is small unless a large casing eccentricity or an initial defect in the cement is present. Some microannuli openings are generated at interfaces cement/casing and/or cement/rock during the CO2 injection because of different thermal shrinkage of each material. However, the width is not important enough to cause significant CO2 leakage under the studied conditions. The use of “flexible” cement especially developed for oil well applications could mitigate the risk of cement cracking during CO2 injection.

Originality/value

Numerous experimental studies on the chemical deterioration of the cement under severe conditions have been carried out. On the other hand, only a few investigations have focused on the mechanical behavior under thermal/pressure changes related to CO2 injection. In this paper, the quantitative analysis to investigate cement cracking and microannuli formation is achieved to help in the identification of possible mechanical defects to cause CO2 leakage. In addition, the discussion about the risk of the possible casing eccentricity and the application of flexible cement in the oil and gas field to CO2 injection well could be practically useful.
Higher technological education specialties and graduates’ vocational status and prospects
Authors: Kostoglou Vassilis , Vassilakopoulos Michael , Koilias Christos
Published: August 2013

Purpose

The purpose of this paper is to focus on a thorough comparison of the broader specialties and subspecialties provided by Greek higher technological education, regarding the employment status and the vocational prospects of the corresponding graduates, and aims to identify and analyze the relevant existing differences.

Design/methodology/approach

Original empirical data were collected from 5,183 graduates of Technological Educational Institutes of higher education through a national survey using telephone interviews and a structured questionnaire. The stratified sample consisted of graduates originating from all nine different broader specialties (faculties) and 45 subspecialties (departments). Descriptive, bivariate and multivariate statistical analysis was used for the elaboration of the collected information.

Findings

The results showed that there are significant differences among the graduates of different specialties regarding some employment characteristics, such as professional status, type of employment, relevance between present work and Bachelor studies, and satisfaction from employment and wages. Additionally, the results identify distinguished clusters among certain broader specialties and subspecialties regarding graduates’ employment status and characteristics.

Practical implications

The revealed existence of strong relationships between broader specialties/subspecialties and their graduates’ vocational prospects can offer justified advice/guidelines to secondary education graduates for applying to specialties presenting promising employment prospects.

Originality/value

This work, being one of the very few nation‐wide studies, reveals and highlights the most important higher education specialties regarding the vocational status and prospects of the corresponding graduates, providing a guideline for the selection of the subject of studies that leads to a more promising career.
A multi-objective antidisturbance robust filter for SINS/GPS navigation systems
Authors: LIU Jia , Zhang Yumin , Guo Lei , Gao Xiaoying
Published: August 2013

Purpose

– A full-order multi-objective anti-disturbance robust filter for SINS/GPS navigation systems with multiple disturbances is designed. Generally, the unmodeled dynamics, the external environmental disturbance and the inertial apparatus random drift may exist simultaneously in an integrated navigation system, which can be classified into three type of disturbances, that is, the Gaussian noise, the norm bounded noise and the time correlated noise. In most classical studies, the disturbances in integrated navigation systems are classified as Gaussian noises or norm bounded noises, where the Kalman filtering or robust filtering can be employed, respectively. While it is not true actually, such assumptions may lead to conservative results. The paper aims to discuss these issues.

Design/methodology/approach

– The Gaussian noises, the norm bounded noises and the time correlated noises in the integrated navigation system are considered simultaneously in this contribution. As a result, the time correlated noises are augmented as a part of system state of the integrated navigation system error model, the relative integrated navigation problem can be transformed into a full-order multi-objective robust filter design problem for systems with Gaussian noises and norm bounded disturbances. Certainly, the errors of the time correlated noises are estimated and compensated for high precision navigation purpose. Sufficient conditions for the existence of the proposed filter are presented in terms of linear matrix inequalities (LMIs) such that the system stability is guaranteed and the disturbance attenuation performance is achieved.

Findings

– Simulations for SINS/GPS integrated navigation system given show that the proposed full-order multi-objective anti-disturbance filter, has stronger robustness and better precision when multiple disturbances exist, that is, the present algorithm not only can suppression the effect of white noises and norm bounded disturbance but also can estimate and compensate the modeled disturbance.

Originality/value

– The proposed algorithm has stronger anti-disturbance ability for integrated navigation with multiple disturbances. In fact, there exist multiple disturbances in integrated navigation system, so the proposed scheme has important significance in applications.
First‐generation college students: mentoring through social media
Authors: Ware Paige , Ramos Jose
Published: August 2013

Purpose

This exploratory study aims to examine how online mentoring was provided through social media to support potential first‐generation Latino college students during their final year of high school and their transition into a two‐year or four‐year institution.

Design/methodology/approach

Using a one‐year qualitative study design, data were collected through interviews, surveys, and archived interactions on Facebook. Discourse analysis was used to code for types of social, informational, and emotional support provided.

Findings

Findings suggest that online mentoring through social media is a support system that the focal students turned to primarily for informational support, rather than for social or emotional support, and its impact seems to be contingent on the existence of conventional mentoring structures of high school counsellors, peers, and family.

Practical implications

High school counsellors and mentors in college outreach programs can leverage students’ presence in social media forums such as Facebook to help structure informational support (application deadlines, financial aid forms, contact information for college outreach) to help students prepare for and transition into college.

Social implications

The visibility and amplification of information delivered through social media provides an untapped resource for assisting first‐generation college students in navigating the complex financial and logistical steps in transitioning to college. Its use as an additional tool for counsellors and mentors could increase matriculation and retention rates.

Originality

High school counsellors and directors of college outreach and mentoring programs could draw on findings in this paper when considering ways to integrate innovative approaches to providing mentoring support.
Determinants of antenatal care quality in Ghana
Authors: Atinga Roger A. , Baku Anita A.
Published: August 2013

Purpose

To achieve Goal 5 of the MDGs, the Government of Ghana introduced the free maternal health service system to break financial barriers of access to maternal care services. In spite of this, facility‐based deliveries continue to be low due partly to poor quality of antenatal care that prevents pregnant women from giving birth in hospitals. The aim of this study is to examine factors shaping quality of antenatal care in selected public hospitals in the country.

Design/methodology/approach

363 expectant mothers were randomly selected for interview. Women who have previously received antenatal care in the health facilities for at least two occasions were interviewed. Multivariate logistic regression model were computed to examine correlates of antenatal care quality.

Findings

The odds of reporting quality of antenatal care as good was higher among women aged between 30 and 34 years. Similarly women with junior/senior high education were more likely to report antenatal care quality as good. Distance to the health facilities generally influence women perception of antenatal care quality but the relative odds of reporting quality of care as good attenuated with proximity to the health facility. Five factors (pleasant interaction with providers, privacy during consultation, attentiveness of providers, adequate facilities and availability of drugs) emerged as statistically significant in explaining antenatal care quality after controlling for selected demographic variables.

Originality/value

Results of the study generally demonstrate the need to improve maternal services in public facilities to stimulate utilisation and facility‐based deliveries.
Toiling children in India: the gender dimension
Authors: Kumar Rajnish , Mitra Arup , Murayama Mayumi
Published: August 2013

Purpose

Child labour in several low‐income households is rather pursued for gaining experience and at times for meagre incomes, which are possibly spent on household food expenditure. The purpose of this paper is to estimate the incidence of child labour and identifies the factors which explain participation of the children in the labour market. It also focuses on some of the outcomes of labour market participation of the children.

Design/methodology/approach

Based on the primary survey of the slum households in four Indian cities this paper applies certain quantitative techniques to estimate child labour and the factors that explain their participation in the labour market.

Findings

Though the contribution made by the child labour to the overall well‐being does not turn out to be substantial, without child labour these households would have been much worse off than the households which can afford not to have child labour. The probability of working is higher for a male child compared to a girl child. This is because the girl children are often engaged in household activities and even when they are engaged in income earning jobs they are shown as helpers. Parents' income as such may not be having a positive impact on child's education.

Originality/value

The study is based on a primary survey. It employs certain indirect methods to arrive at a more realistic estimate of the incidence of child labour. Besides, it focuses on the quantitative methods to identify the factors that explain child labour. Finally the policy implications are brought out.
Useful and easy-to-use interactive voice for emergency data exchange
Authors: Waidyanatha Nuwan , Perera Kasun , Silva Manoj , Burrell Brenda , Sigauke Tichafara
Published: August 2013

Purpose

– Telephone calls are the predominant telecommunication mode in Sri Lanka. Consequently, leveraging voice-based applications for disaster communication would be acceptable and sustainable. The purpose of this paper is to realise the design requirements for an integrated voice-enabled alerting and reporting system, and then to use the lessons learned to influence disaster management researchers, practitioners and developers to invest resources in related new system developments.

Design/methodology/approach

– The findings in this paper are from an experiment concerning interactive voice for connecting community-based emergency field operatives with their central co-ordination hub.

Findings

– A particular challenge was in interchanging Sinhala and Tamil language speech data, generated by the Freedom Fone Interactive Voice Response, with the text-based “Sahana” disaster-management system for analysis and decision support. The Emergency Data Exchange Language interoperable content standard was adopted for mediation between the two disparate systems. Standard mobile phones were the interface linking the Community Emergency Response Team (CERT) members. Low quality voice transmissions over the GSM cellular infrastructure resulted in distorted data. This shortcoming was a barrier to automating transformations between text and speech.

Originality/value

– Replacing those processes with human procedure significantly degrades their reliability. Nevertheless, the CERT members find voice-enabled information exchange useful and easy to use, because it diminishes the need for computer literacy and removes language barriers. The paper discusses the utility evaluation of the introduced system.
Application of the Rohman-Stork price basket to unlock the complexities of cellular price in Indonesia
Authors: Kholilul Rohman Ibrahim , Stork Christoph
Published: August 2013

Purpose

–The purpose of this paper is to demonstrate the complexity of prepaid mobile pricing in Indonesia and suggest tools that allow consumers to make informed decisions.

Design/methodology/approach

–Defining a basket of services and pricing it for all prepaid mobile products available in Indonesia.

Findings

–Findings suggested the importance of price transparency to ensure that consumers are well-informed concerning the range of services and prices available.

Practical implications

–The paper provides recommendations for the Indonesian Telecommunication Regulation Agency (BRTI), which could use price baskets to create transparency and monitor price developments in the market. Another measure BRTI could undertake is to require any advertisement to include the cost for a price basket defined by BRTI.

Social implications

–Price transparency is likely to lead to price competition and thus lower prices and/or better services. The economic impact of lower prices is well documented.

Originality/value

–The authors have developed a unique basket methodology to address the specific situation in Indonesia.
Internet going mobile: internet access and use in 11 African countries
Authors: Stork Christoph , Calandro Enrico , Gillwald Alison
Published: August 2013

Purpose

– The purpose of this paper is to analyse internet access and use trends in 11 African countries based on household and individual ICT survey data.

Design/methodology/approach

– The study uses nationally representative data for households and individuals in residential and semi-residential areas, as defined by national census sample frames for 11 African countries.

Findings

– While the 2007/2008 African ICT access and use survey demonstrated alarmingly little access to the internet on the continent, together with a large-scale absence of computers and smart phones, compounded by the high cost of connectivity, the mobile phone is now the key entry point for internet use. Internet access has increased significantly across all countries, as a result increasing internet penetration to 15.5 per cent across the 11 African countries surveyed by Research ICT Africa in 2011/2012. Mobile internet requires fewer ICT skills, less financial resources and does not rely on electricity at home, compared to computers or laptops. Other findings highlight the unevenness of internet take-up across and within countries. Thus, while the majority of the countries under investigation demonstrate increased mobile internet take-up, in Rwanda, Tanzania and Ethiopia, internet use remains negligible. In those countries where mobile internet is boosting connectivity, this is being driven by social networking applications.

Practical implications

– The policy implications of the shift in significant numbers from negligible internet access at public access points serviced primarily by fixed access lines to mobile internet access are significant. Just as traditional reform strategies of increasing competition in the market increased access to voice services more successfully than traditional universal service strategies, mobile again appears to be addressing the internet gap. Competition in mobile markets appears to address the efficiency gap in the market, resulting in an increase in the choice of services and a reduction in prices. Strategies that seek to aggregate users at public access points, funded by complex levies and subsidies again seem to have been overtaken by the increasing availability of mobile internet access, as feature phones and smart phone become more available to individual users.

Social implications

– Understanding prepaid mobile internet further provides a pro-poor dimension to public policies seeking to improve internet access, which historically has been available and affordable to the elite. The rest of the society had to rely on public access points, whether private internet cafés or schools and libraries.

Originality/value

– This paper uses primary data that allow a better understanding of internet access and use in Africa. It provides policymakers and regulators with the evidence required for an informed ICT policy and regulation.
ICT policy and poverty reduction in Africa
Authors: Diga Kathleen , Nwaiwu Fortune , Plantinga Paul
Published: August 2013

Purpose

– The purpose of this paper is to understand how policymakers in different African countries negotiate the complex relationship between information and communication technologies (ICTs) and poverty reduction. The authors adopt a novel perspective on this problem by considering how the broader policy discourse and associated mechanisms tend to address (or neglect) the multiple dimensions of poverty.

Design/methodology/approach

– A textual analysis was conducted on selected ICT and poverty reduction policy documents from Uganda, South Africa and Nigeria, between 2005 and 2012.

Findings

– The findings show that the focus of ICT policy interventions continues to be on increasing economic capabilities amongst the poor. There is recognition in all three cases that human, political and social capital are also important. The continued dominance of an economic focus within ICT policies is supported by a techno-deterministic policy discourse, which tends to downplay social factors. Meanwhile, poverty reduction strategies adopt a similarly techno-deterministic perspective on the role of ICTs in development.

Practical implications

– While there is negligible evidence of methods that could enable a more contested, discursive policy environment, there are signs in South Africa and Uganda of a strong but relatively high-level (and largely rhetorical) interest in participatory approaches to ICT implementation which may, if appropriated fully by policymakers and their agents, lead to a more contextually anchored approach to ICT-supported poverty reduction around a diverse mix of poverty dimensions.

Originality/value

– This paper has developed a novel framework for analysing the extent to which the multiple dimensions of poverty are being addressed within African ICT policy and whether the appropriate institutional arrangements and policy processes are being adopted to do this.
Calibrating distance mapping of non‐SVP catadioptric camera of the soccer robot
Authors: Zhu Xiaoxiao , Cao Qixin
Published: August 2013

Purpose

The purpose of the present paper is to propose a full model‐based method for distance‐mapping calibration for the non‐SVP (non‐single viewpoint) catadioptric camera of the soccer robot. The method should be easy to operate, efficient, accurate, and scalable to fit larger field sizes.

Design/methodology/approach

The distance‐mapping model was first constructed based on the imaging principle. The authors then calibrated the internal parameters using the mirror boundary and used the mirror center to choose the correct pose from two possible solutions. The authors then proposed a three‐point method based on a unique solution case of the non‐SVP P3P (perspective‐three‐point) problem to solve the external parameters. Lastly, they built the distance mapping by back‐projection.

Findings

The simulation experimental results have shown that the authors' method is very accurate even when there is severe misalignment between the mirror and the camera and that all calibration operations, except the calibration of a standard camera, can be completed in 1 min. The result of the comparison with the traditional calibration method shows that the authors' method is superior to the traditional method in terms of accuracy and efficiency.

Originality/value

The proposed calibration method is scalable to larger fields because it only uses the boundary of the mirror and three feature points on the field, and does not need additional calibration objects. Additionally, an automatic calibration method that can be used during the game can be easily developed based on this method. Moreover, the proposed mirror‐pose‐selection method and a unique solution to the non‐SVP P3P problem are especially useful for a non‐SVP catadioptric camera.
IPO valuation and insider manipulation of R&D
Authors: Hull Robert , Walker Rosemary , Kwak Sungkyu
Published: August 2013

Purpose

The purpose of this paper is to examine the effects of R&D manipulation on stock valuation for periods around IPOs. Insider manipulation is the difference in actual R&D change minus predicted R&D change where a negative difference indicates R&D underinvestment.

Design/methodology/approach

This study is designed to build on prior IPO research that has found reduced R&D expenditures when insiders lower their ownership. The paper derives an R&D manipulation variable that measures underinvestment in R&D. This variable is used in a regression methodology to test its influence on: IPO stock valuation at various points in time and post‐IPO price changes relative to the offer price.

Findings

The paper discovers that greater underinvestment in R&D is associated with greater values during the IPO stock valuation process. This association is reversed when the paper looks at short‐term valuation based on market prices. Only for bubble period IPOs do the paper finds poorer valuations for the long‐term. Larger insider ownership decreases lead to poorer valuations regardless of the period of occurrence. Greater R&D underinvestment and insider ownership decreases both lead to less underpricing.

Research limitations/implications

Like prior research, the paper assumes that knowledge about the change in R&D is known at the time of the offering. Interpretations for long‐run results can be tenuous due to unexpected changes that occur over time.

Practical implications

Investors should note that managers are able to set higher offer prices when they inflate earnings by underinvesting in R&D. Buying at an inflated offer price with R&D manipulation leads to losses in the aftermarket with these losses associated with IPOs that occur during a bubble period.

Social implications

Misrepresentation during the IPO valuation process affects those who buy shares at inflated prices. This raises ethical questions about the behavior of those involved in the issuance process.

Originality/value

This study is unique in testing how R&D manipulation and changes in insider ownership proportions impact the: IPO valuation process, post‐IPO valuation, and changes in the stock price over time relative to the offer price.
Personal consequences of the diagnosis of schizophrenia: a preliminary report from the inquiry into the schizophrenia label
Authors: Thomas Philip , Seebohm Patience , Wallcraft Jan , Kalathil Jayasree , Fernando Suman
Published: August 2013

Purpose

The purpose of this survey was to describe the impact of the diagnosis of schizophrenia on the lives of people who receive the diagnosis.

Design/methodology/approach

The authors designed a questionnaire to investigate attitudes to and experiences of the diagnosis of schizophrenia. After a pilot study, they made the questionnaire available online and, through a network of service user and other organisations, solicited responses.

Findings

Of the 470 responses, 27.4 per cent were from service users. Content analysis of their responses revealed three main categories: concern with the consequences of the diagnosis and its negative impact on their lives, the life contexts of individuals before receiving the diagnosis, and concerns with medication and treatment. This paper deals with the first two.

Research limitations/implications

It is impossible to generalise the results of this survey because respondents self‐selected, and thus might be expected to have strong feelings against (or for) the diagnosis of schizophrenia.

Practical implications

The diagnosis of schizophrenia in this sample had devastating negative implications. It was experienced as harmful and stigmatising. Very few people understood their experiences as a biomedical disorder.

Social implications

A gulf exists between the experiences of people diagnosed with schizophrenia and the concerns of academics and others currently involved in debates about the merits of different systems of diagnosis.

Originality/value

This survey is valuable because it draws attention to experiences of diagnosis that are easily lost in the storm of academic controversies about diagnosis in psychiatry.
New designs and software for cognitive causal mapping
Authors: Laukkanen Mauri , Eriksson Päivi
Published: August 2013

Purpose

The paper's first objective is to develop a new conceptual framework for categorizing and designing cognitive, specifically comparative, causal mapping (CCM) research by building upon the theory‐centred and participant‐centred perspectives. The second purpose is to enable the discerned study prototypes by introducing a new CCM software application, CMAP3.

Design/methodology/approach

Building upon the distinction between theory‐centred (etic) and participant‐centred (emic) perspectives in social research, we first construct and apply a conceptual framework for analysing and categorising extant CCM studies in terms of their objectives and basic design. Next, after noting the important role and basic tasks in computerising causal mapping studies, we present a new CCM software application.

Findings

The theory‐centred/participant‐centred perspectives define four causal mapping study prototypes, each with different goals, basic designs and methodological requirements. Noting the present lack of widely accessible software for qualitatively oriented CCM studies, we introduce CMAP3, a new non‐commercial Windows application, and summarise how it is used in related research.

Originality/value

The framework and the studies representing the prototypes demonstrate the versatility of CCM methods and that the proposed framework offers a new, systematic approach to categorising and designing CCM studies. Research technically, CMAP3 can support the defined CCM‐prototypes, based on a low‐structured (inductive/qualitative) or a structured (nomothetic/quantitative) methodological approach/stance, and having therefore different needs of data acquisition, processing, coding, aggregation/comparison, and analysis of the emerging aggregated cause maps’ contents or structure.
The within‐species leaf economic spectrum does not predict leaf litter decomposability at either the within‐species or whole community levels
Authors: Jackson Benjamin G. , Peltzer Duane A. , Wardle David A.
Published: August 2013

Despite recent progress in characterizing the within‐species variability (WSV) of plant functional traits, the importance of this WSV in driving ecological processes such as leaf litter decomposability within species or at the whole community level is poorly understood.

We ask whether leaf and litter functional traits vary within species to form a spectrum of variability analogous to the leaf economics spectrum that occurs among species. We also ask whether this spectrum of trait variation within species is an important driver of leaf litter decomposability. To address these questions, we quantified both WSV and between‐species variation of leaf and litter traits and litter decomposability of 16 co‐occurring temperate rain forest plant species along soil toposequences characterized by strong shifts in soil nutrient status in New Zealand.

We found considerable WSV of both leaf and litter traits for all species, and a within‐species spectrum of coordinated trait variation for 11 species. The WSV of leaf and to a lesser extent foliar litter C to N and C to P values were often strongly related to soil C to N and C to P ratios across plots. Further, in many cases, WSV and its covariation with species turnover contributed significantly to the community‐level aggregate trait response to variation in soil fertility.

Contrary to our expectations, the WSV in leaf and litter traits did not generally predict within‐species variation in leaf litter mass loss, nor N and P release, during decomposition. Further, inclusion of WSV did not improve predictions of leaf litter decomposability using community‐level trait measures.

Synthesis. Our findings support the view that WSV of plant functional traits is an important component of plant community responses to environmental factors such as soil fertility. However, the apparent decoupling of WSV of leaf economic traits from WSV of ecological processes such as litter decomposability suggests that consideration of WSV may not be necessary to understand the contributions of trait variation to determining the breakdown of plant litter and therefore, potentially, ecosystem processes.
Trend analysis and modelling of gender‐specific age, period and birth cohort effects on alcohol abstention and consumption level for drinkers in Great Britain using the General Lifestyle Survey 1984–2009
Authors: Meng Yang , Holmes John , Hill‐McManus Daniel , Brennan Alan , Meier Petra Sylvia
Published: August 2013

Background and aims

British alcohol consumption and abstinence rates have increased substantially in the last 3 decades. This study aims to disentangle age, period and birth cohort effects to improve our understanding of these trends and suggest groups for targeted interventions to reduce resultant harms.

Design

Age, period, cohort analysis of repeated cross‐sectional surveys using separate logistic and negative binomial models for each gender.

Setting

Great Britain 1984–2009.

Participants

Annual nationally representative samples of approximately 20 000 adults (16+) within 13 000 households.

Measurements

Age (eight groups: 16–17 to 75+ years), period (six groups: 1980–84 to 2005–09) and birth cohorts (19 groups: 1900–04 to 1990–94). Outcome measures were abstinence and average weekly alcohol consumption. Controls were income, education, ethnicity and country.

Findings

After accounting for period and cohort trends, 18–24‐year‐olds have the highest consumption levels (incident rate ratio = 1.18–1.15) and lower abstention rates (odds ratio = 0.67–0.87). Consumption generally decreases and abstention rates increase in later life. Until recently, successive birth cohorts' consumption levels were also increasing. However, for those born post‐1985, abstention rates are increasing and male consumption is falling relative to preceding cohorts. In contrast, female drinking behaviours have polarized over the study period, with increasing abstention rates accompanying increases in drinkers' consumption levels.

Conclusions

Rising female consumption of alcohol and progression of higher‐consuming birth cohorts through the life course are key drivers of increased per capita alcohol consumption in the United Kingdom. Recent declines in alcohol consumption appear to be attributable to reduced consumption and increased abstinence rates among the most recent birth cohorts, especially males, and general increased rates of abstention across the study period.
Chylous ascites as a complication of laparoscopic colorectal surgery
Authors: Matsuda Takeru , Fujita Hirofumi , Kunimoto Yukihiro , Kimura Taisei , Ogino Kazunori
Published: August 2013

Introduction

Until now, no data have been available on the incidence of chylous ascites after laparoscopic colorectal surgery.

Methods

From January 2007 to December 2011, 137 patients with colorectal cancer underwent laparoscopic surgery at our institution. The clinical data of the patients with postoperative chylous ascites were compared with those of the patients without chylous ascites.

Results

Chylous ascites developed in 9 of the 137 patients (6.5%). Blood loss, operative time, tumor location, and extent of lymph node dissection were not associated with postoperative chylous ascites. Mean postoperative hospital stay for patients with chylous ascites was significantly longer than that for patients without any complications (14 days vs 10 days; P < 0.001). Recurrence was observed in two of the nine patients with chylous ascites; it developed locally and in the liver in one patient, and peritoneal dissemination was seen in the other. The recurrence rate in the chylous ascites group (22.2%) was significantly higher than that in the non‐chylous ascites group (3.9%; P = 0.016). The 3‐year disease‐free survival in the chylous ascites group (76.2%) was significantly lower than that in the non‐chylous ascites group (93.4%; P = 0.020); however, the 3‐year overall survival rates did not differ between the groups (87.5% vs 94.4%, respectively; P = 0.332).

Conclusion

Chylous ascites are not a rare complication of laparoscopic colorectal surgery. It was managed conservatively in all cases but was associated with longer hospital stays. We recommend careful tissue dissection at a suitable plane and meticulous clipping during lymphadenectomy to prevent chyle leakage when lymphatic invasion is suspected.
Functional pharmacology of H1 histamine receptors expressed in mouse preoptic/anterior hypothalamic neurons
Authors: Tabarean I V
Published: August 2013

Background and Purpose

Histamine H1 receptors are highly expressed in hypothalamic neurons and mediate histaminergic modulation of several brain‐controlled physiological functions, such as sleep, feeding and thermoregulation. In spite of the fact that the mouse is used as an experimental model for studying histaminergic signalling, the pharmacological characteristics of mouse H1 receptors have not been studied. In particular, selective and potent H1 receptor agonists have not been identified.

Experimental Approach

Ca2+ imaging using fura‐2 fluorescence signals and whole‐cell patch‐clamp recordings were carried out in mouse preoptic/anterior hypothalamic neurons in culture.

Key Results

The H1 receptor antagonists mepyramine and trans‐triprolidine potently antagonized the activation by histamine of these receptors with IC50 values of 0.02 and 0.2 μM respectively. All H1 receptor agonists studied had relatively low potency at the H1 receptors expressed by these neurons. Methylhistaprodifen and 2‐(3‐trifluoromethylphenyl)histamine had full‐agonist activity with potencies similar to that of histamine. In contrast, 2‐pyridylethylamine and betahistine showed only partial agonist activity and lower potency than histamine. The histamine receptor agonist, 6‐[2‐(4‐imidazolyl)ethylamino]‐N‐(4‐trifluoromethylphenyl)heptanecarboxamide (HTMT) had no agonist activity at the H1 receptors H1 receptors expressed by mouse preoptic/anterior hypothalamic neurons but displayed antagonist activity.

Conclusions and Implications

Methylhistaprodifen and 2‐(3‐trifluoromethylphenyl)histamine were identified as full agonists of mouse H1 receptors. These results also indicated that histamine H1 receptors in mice exhibited a pharmacological profile in terms of agonism, significantly different from those of H1 receptors expressed in other species.
A single channel mutation alters agonist efficacy at 5‐HT3A and 5‐HT3AB receptors
Authors: Thompson A J , Lummis S C R
Published: August 2013

Background and Purpose

5‐HT3 receptors are composed of 5‐HT3A subunits (homomeric receptors), or combinations of 5‐HT3A and other 5‐HT3 receptor subunits (heteromeric receptors, the best studied of which are 5‐HT3AB receptors). Here we explore the effects of partial agonists at 5‐HT3A and 5‐HT3AB receptors, and the importance of a channel‐lining residue in determining the efficacy of activation.

Experimental Approach

Wild type and mutant 5‐HT3A and 5‐HT3AB receptors were expressed in Xenopus oocytes and examined using two‐electrode voltage‐clamp, or expressed in HEK293 cells and examined using [3H]granisetron binding.

Key Results

Dopamine, quipazine and VUF10166 were partial agonists at wild type 5‐HT3A and 5‐HT3AB receptors, with quipazine and VUF10166 causing a long‐lived (>20 min) inhibition of subsequent agonist responses. At 5‐HT3A receptors, mCPBG was a partial agonist, but was a superagonist at 5‐HT3AB receptors, as it produced a response 2.6× greater than that of 5‐HT. A T6'S substitution in the 5‐HT3A subunit decreased EC50 and increased Rmax of dopamine and quipazine at both homomeric and heteromeric receptors. The greatest changes were seen with VUF10166 at 5‐HT3AT6'SB receptors, where it became a full agonist (EC50 = 7 nM) with an EC50 58‐fold less than 5‐HT (EC50 = 0.4 μM) and no longer caused inhibition of subsequent agonist responses.

Conclusions and Implications

These results indicate that a mutation in the pore lining domain in both 5‐HT3A and 5‐HT3AB receptors alters the relative efficacy of a series of agonists, changing some (e.g. quipazine) from apparent antagonists to potent and efficacious agonists.
SERCA2a stimulation by istaroxime: a novel mechanism of action with translational implications
Authors: Huang Christopher L H
Published: August 2013

Sarcoplasmic reticular (SR) Ca2+‐ATPase (SERCA2a) is central to cardiac electrophysiological and mechanical function. It ensures full diastolic relaxation minimizing delayed after‐potentials that would otherwise compromise membrane electrophysiological stability, and optimizes SR Ca2+ refilling and systolic contraction. Previous studies demonstrated that the small molecule agent istaroxime stimulates SERCA2a‐ATPase activity, restoring its function in failing hearts, and enhancing indices of mechanical, and SR Ca2+ release and re‐uptake, activity. Ferrandi et al (2013) now elegantly demonstrate its ability to dissociate the phospholamdan (PB) bound to cardiac SERCA2a, thereby removing the inhibitory effect of PB on SERCA2a. This effect was independent of the cAMP/PKA system and modified a specific SERCA2a reaction step. They used SERCA‐enriched SR preparations from a rigorously validated and realistic physiological, canine model of cardiac failure with established Na+‐K+‐ATPase sensitivity to cardiac glycosides and SR Ca2+ handling features. These findings potentially translate into a novel management of the major and increasingly important public health challenge of chronic cardiac failure.

Linked Article

This article is a commentary on Ferrandi et al., pp. 1849–1861 of volume 169 issue 8. To view this paper visit http://dx.doi.org/10.1111/bph.12278.
Nitrite in organ protection
Authors: Rassaf Tienush , Ferdinandy Peter , Schulz Rainer
Published: August 2013

In the last decade, the nitrate‐nitrite‐nitric oxide pathway has emerged to therapeutical importance. Modulation of endogenous nitrate and nitrite levels with the subsequent S‐nitros(yl)ation of the downstream signalling cascade open the way for novel cytoprotective strategies. In the following, we summarize the actual literature and give a short overview on the potential of nitrite in organ protection.
Effect of Mas‐related gene (Mrg) receptors on hyperalgesia in rats with CFA‐induced inflammation via direct and indirect mechanisms
Authors: Jiang Jianping , Wang Dongmei , Zhou Xiaolong , Huo Yuping , Chen Tingjun , Hu Fenjuan , Quirion Rémi , Hong Yanguo
Published: August 2013

Background and Purpose

Mas oncogene‐related gene (Mrg) receptors are exclusively distributed in small‐sized neurons in trigeminal and dorsal root ganglia (DRG). We investigated the effects of MrgC receptor activation on inflammatory hyperalgesia and its mechanisms.

Experimental Approach

A selective MrgC receptor agonist, bovine adrenal medulla peptide 8‐22 (BAM8‐22) or melanocyte‐stimulating hormone (MSH) or the μ‐opioid receptor (MOR) antagonist CTAP was administered intrathecally (i.t.) in rats injected with complete Freund's adjuvant (CFA) in one hindpaw. Thermal and mechanical nociceptive responses were assessed. Neurochemicals were measured by immunocytochemistry, Western blot, ELISA and RT‐PCR.

Key Results

CFA injection increased mRNA for MrgC receptors in lumbar DRG. BAM8‐22 or MSH, given i.t., generated instant short and delayed long‐lasting attenuations of CFA‐induced thermal hyperalgesia, but not mechanical allodynia. These effects were associated with decreased up‐regulation of neuronal NOS (nNOS), CGRP and c‐Fos expression in the spinal dorsal horn and/or DRG. However, i.t. administration of CTAP blocked the induction by BAM8‐22 of delayed anti‐hyperalgesia and inhibition of nNOS and CGRP expression in DRG. BAM8‐22 also increased mRNA for MORs and pro‐opiomelanocortin, along with β‐endorphin content in the lumbar spinal cord and/or DRG. MrgC receptors and nNOS were co‐localized in DRG neurons.

Conclusions and Implications

Activation of MrgC receptors suppressed up‐regulation of pronociceptive mediators and consequently inhibited inflammatory pain, because of the activation of up‐regulated MrgC receptors and subsequent endogenous activity at MORs. The uniquely distributed MrgC receptors could be a novel target for relieving inflammatory pain.
A single‐center analysis of abdominal imaging in the evaluation of kidney transplant recipients
Authors: Winship Brenton , Ramakrishnan Swetha , Evans Jonathan , Lurie Christina , Martin Diego , Pearson Thomas , Turgeon Nicole
Published: August 2013

Many transplantation programs utilize noninvasive abdominal and pelvic imaging in the pre‐operative evaluation of recipient candidates. Practice patterns vary, and consensus guidelines addressing the risks and benefits of computed tomography (CT) and magnetic resonance imaging (MRI) in the pre‐transplant evaluation process do not currently exist. In this single‐center study, we examined the frequency, clinical significance, and associated costs of CT and MRI findings during the pre‐transplant evaluation of renal transplant recipients. A retrospective chart review of 3041 adult patients who underwent a CT/CTA or MRI/MRA of the abdomen and pelvis for pre‐transplant evaluation between 2005 and 2010 was performed. Pre‐transplant imaging with MRI offered a more sensitive evaluation in comparison with CT, with the notable exception of abnormalities in which calcium was detected. Patients imaged with CT had a significantly greater proportion of subsequent clinical actions arising from imaging findings. The total financial cost of MRI was greater than that of CT. No cases of nephrogenic systemic fibrosis (NSF) in patients who received MultiHance gadolinium contrast were reported. In conclusion, the risks, benefits, and costs of CT/CTA and MRI/MRA must be carefully considered to optimize the pre‐operative evaluation of renal transplant recipients.
Inter‐specific competition and competition‐free space in the tephritid parasitoids Utetes anastrephae and Doryctobracon areolatus (Hymenoptera: Braconidae: Opiinae)
Authors: ALUJA MARTIN , OVRUSKI SERGIO M. , SIVINSKI JOHN , CÓRDOVA‐GARCÍA GUADALUPE , SCHLISERMAN PABLO , NUÑEZ‐CAMPERO SEGUNDO R. , ORDANO MARIANO
Published: August 2013

Utetes anastrephae (Viereck) and Doryctobracon areolatus (Szépligeti) are common, native, Neotropical braconid parasitoids of tephritid fruit flies that are sympatric and often found attacking the same host.

The coexistence of the two species may be due in part to the longer ovipositor of D. areolatus that permits it to attack larvae in larger fruit than can U. anastrephae. This increases its potential host range and provides ‘competitor‐free space’.

The capacity of U. anastrephae to persist in smaller fruit, exploitable by D. areolatus, suggested that it was a superior competitor in multiparasitised hosts. As predicted U. anastrephae had a competitive advantage over D. areolatus and this advantage occurred regardless of the order in which the two parasitoids attacked. Although we could not identify the precise mechanisms used for elimination of competitors, a possible cause is suggested by the formidable mandibles of the first‐instar U. anastrephae.

However, D. areolatus survival increased significantly if eggs had been deposited 24 h prior to exposure to U. anastrephae. Older D. areolatus larvae might be more competitive after a period of development.

Utetes anastrephae females were less likely to oviposit into hosts previously attacked by D. areolatus than vice versa. This was a second case of the relatively rare phenomenon of inter‐specific discrimination of a previously exploited host within the opiine braconid parasitoids of frugivorous tephritids.
Network mechanisms of responsiveness to continuous theta‐burst stimulation
Authors: Rizk Sviatlana , Ptak Radek , Nyffeler Thomas , Schnider Armin , Guggisberg Adrian G.
Published: August 2013

Continuous theta‐burst stimulation (cTBS) can modify behavior, but effects are inconsistent and their mechanisms insufficiently understood. As coherence in resting‐state networks influences human behavior, we hypothesized that cTBS may act via modulation of neural oscillation coherence. This study used electroencephalography (EEG) to investigate whether behavioral effects of cTBS on visuospatial attention are associated with coherence changes in the attention network. In healthy human subjects, cTBS of the right posterior parietal cortex (PPC) and the right frontal eye field was compared with sham stimulation. Effects on visuospatial attention were quantified with a visual exploration task, and network effects were assessed from surface EEG with inverse solutions and source coherence analyses. Before stimulation, left visual exploration was linearly correlated with alpha‐band coherence between the right temporo‐parietal cortex and the rest of the brain. Posterior parietal cortex stimulation induced neglect‐like visual exploration behavior in the majority, but not all, subjects. It reduced alpha‐band coherence between the stimulation site and the rest of the brain but also enhanced it between the contralateral left parietal cortex and the rest of the brain. The contralateral increase correlated with the induced reduction in left visual attention. The behavioral response of individual participants to cTBS could be predicted by coherence in the right temporo‐parietal junction before stimulation. Behavioral effects of cTBS therefore depend on network states before stimulation and are linearly associated with changes in network interactions. In particular, cTBS modulates an interhemispheric competition in alpha‐band coherence. EEG network imaging might help to optimize therapeutic cTBS in the future.