bluuebunny/crossref_metadata_2025 huggingface dataset:
Open innovation processes within clusters – the role of tertius iugens
Authors: Crespin-Mazet Florence , Goglio-Primard Karine , Scheid François
Published: September 2013

Purpose

– Little research focuses on the conditions under which companies open up to co-develop knowledge with external actors. Spatial proximity has been proved insufficient to generate successful open innovation processes: socio-economic proximity also seems required. This paper aims at better understanding how this new form of proximity can be organized and investigates the role of third parties or tertius iungens in this process.

Design/methodology/approach

– This paper is based on an exploratory case of successful open innovation between a software editor and a systems integrator located in the same cluster, relying on 50 face-to-face in-depth interviews, documentation and analysis of physical artifacts.

Findings

– It confirms that socio-economic and in particular coordination proximity favors open innovation processes. This proximity is facilitated by a third party acting as a sustained iungens to initiate contact between development partners and key customers, and to practically organize knowledge transfer. The paper suggests that to be effective this tertius iungens needs to occupy a central position in the local network and to exhibit the characteristics of an epistemic community.

Research limitations/implications

– Due to its exploratory design, the authors' research exhibits several limitations in terms of generalization. It does not fully appreciate the specific interaction between the various dimensions of proximity and in what respect spatial proximity positively influences or reinforces the development of socioeconomic proximity. Further research is needed to analyze the relationships between these various forms of proximity and understand whether spatial proximity is required in a context where new information technologies ease up relationship and coordination mechanisms. Another limitation is linked to the character of the open innovation project analyzed which focused on an innovation of exploitation.

Practical implications

– This paper suggests that territorial engineering should favor the emergence of organizations playing the role of tertius iungens in the local network. Such organizations need to have the technical expertise and image of benevolence and integrity to manage knowledge transfer.

Originality/value

– Little research analyzes the role of third parties or tertius iungens in the emergence and management of open innovation processes. The literature on clusters has mostly highlighted that inter-organizational cooperation emerges from spatial proximity and can be organized by public authorities whereas most of the open innovation literature on software describes cooperation patterns that do not require any third party.
A comparative assessment of videoconference and face-to-face employment interviews
Authors: J. Sears Greg , Zhang Haiyan , H. Wiesner Willi , D. Hackett Rick , Yuan Yufei
Published: September 2013

Purpose

– Based on theories of media richness and procedural justice, the authors aim to examine the influence of videoconferencing (VC) technology on applicant reactions and interviewer judgments in the employment interview, the most commonly used employee selection device.

Design/methodology/approach

– MBA students participated in simulated VC and face-to-face (FTF) interviews. Applicant perceptions of procedural justice and interviewer characteristics were collected. Interviewers provided ratings of affect toward the applicant, perceived applicant competence, overall interview performance, as well as an overall hiring recommendation.

Findings

– Applicants perceived VC interviews as offering less of a chance to perform and as yielding less selection information. They also viewed VC interviews as less job-related than FTF interviews and had significantly less favorable evaluations of their interviewer (on personableness, trustworthiness, competence, and physical appearance) in VC interviews. Finally, applicants in VC interviews received lower ratings of affect (likeability) and lower interview scores, and were less likely to be recommended for the position.

Research limitations/implications

– The authors' findings suggest that VC technology can adversely affect both applicant reactions and interviewer judgments. They propose several precautionary steps to help minimize the risks associated with conducting VC interviews.

Originality/value

– The authors extend prior research concerning the use of VC interviews by directly assessing applicant perceptions of both procedural justice and of interviewer characteristics associated with the probability that job offers will be accepted. They also add to the literature in showing that VC interviews tend to result in less favorable evaluations of applicants than FTF interviews.
Strategic capabilities in exporting: an examination of the performance of Mexican firms
Authors: M. Rodriguez Carlos , A. Wise Jorge , Ruy Martinez Carlos
Published: September 2013

Purpose

– This study aims to examine in the context of high involvement exporting Mexican firms a model which suggests that a blend of absorptive and dynamic capabilities is necessary to build and sustain their competitiveness in international markets.

Design/methodology/approach

– Data were collected from 119 high involvement Mexican exporting firms through informants. Formative and reflective constructs were validated through MIMIC models and confirmatory factor analysis using LISREL. The theoretical model was tested using partial least squares (PLS).

Findings

– Results suggest that high involvement Mexican exporting firms' capacity to adapt through product design, technology management, manufacturing processes, and cooperative relationships impacts their innovation and market expansion-adaptation capabilities. Nurturing an entrepreneurship orientation is critical to build flexibility, transfer innovation to markets, and drive export performance. Ultimately, performance is determined by the firms' ability to design and develop products through the adoption of improved technologies, a deep understanding of international demands, and an ability to refocus exporting strategies as changes in competitive contexts require.

Research limitations/implications

– The design of exporting capabilities in this study only applies to high involvement exporting firms.

Practical implications

– High involvement exporting firms sustain growth through the development of exploration (learning), exploitation (expansion-adaptation), and dynamic (innovation, entrepreneurship) capabilities as determinant of performance.

Originality/value

– This is the first model that tests relationships among learning, manufacturing flexibility, and market expansion-adaptation and dynamic capabilities such as innovation and entrepreneurship and their impact on performance in high involvement Mexican exporting firms.
Pressures affecting green supply chain performance
Authors: M. Lee Sang , Sung Rha Jin , Choi Donghyun , Noh Yonghwi
Published: September 2013

Purpose

– This study aims to empirically investigate the relationship between the directions of pressures affecting green supply chain management (GSCM) and supply chain (SC) performance.

Design/methodology/approach

– This research is based on a survey because there is no archival database providing detailed information on GSC practices and performance. A survey questionnaire was developed to collect research data, based on the GSC literature and a pilot study in the field. The authors developed hypotheses based on two theories: institutional theory and the resource-based view (RBV). Confirmatory factor analysis (CFA) and structural equation modeling (SEM) were used to test the hypotheses with SPSS (16.0) and AMOS (5.0).

Findings

– The results confirmed the importance of implementing environmental SC practices to sustain organizations' competitive advantage and performance. Increased SC flexibility helped reduce resources, through decreased cost factors and improved output. Enterprises with environmental SC policies tended to increase SC flexibility and, hence, enhanced profits.

Originality/value

– This paper applies organizational theories to GSCM by extending the institutional-versus-internal-pressure construct to the way enterprises implement GSC strategies for sustainable SC.
Supervised community treatment: patient perspectives in two Merseyside mental health teams
Authors: Michael Fahy Gary , Javaid Syed , Best Jonathan
Published: September 2013

Purpose

– This paper explores the perspectives of patients subject to supervised community treatment (SCT) within two mental health teams in Merseyside.

Design/methodology/approach

– A structured survey tool was developed to explore patient perspective. In total, 17 patients agreed to participate in the study subject to informed consent.

Findings

– The majority of patients believed SCT facilitated early hospital discharge but felt uninvolved in the process. A significant proportion lacked the motivation or ability to understand the verbal and written information pertaining to their legal rights at the time it was given, usually immediately prior to hospital discharge. All felt they must strictly abide to the SCT conditions to remain in the community. There was a lack of knowledge about the harm criteria and the responsible clinician's ability to recall a service user to hospital even if they abided by the conditions.

Research limitations/implications

– This study is based upon a small sample size. There is no attempt to generalise the results.

Originality/value

– There have been few studies exploring the perspective of patients subject to SCT. A fuller awareness and understanding of patient perspective is important to promote involvement and therapeutic outcomes.
Inventory accumulation, location and financial structure: evidence from China
Authors: Liu Pu , Shao Yingying
Published: September 2013

Purpose

– The purpose of this paper is to empirically examine the relationship between firms' inventory accumulation and financial structure. It further investigates the impact of geographical locations on firms' inventory investment decision after controlling for firms' financial structure.

Design/methodology/approach

– This paper uses a large panel of over 1,400 Chinese listed firms that issued.

Findings

– Firms' financial structure, as reflected in the availability of internal and external capital, has significant impact on firms' inventory decisions. In addition, it is found that firms headquartered in major economic development areas (EDA) tend to have slower inventory growth than firms located in rural areas. Moreover, the results reveal that locating in major EDA facilitates firms' stockpiling of inventories through easy access to external capital.

Originality/value

– This study not only contributes to the studies on the interactions between firms' location and their financing and investment policy, but also improves our understanding about emerging markets such as China.
Marked seasonality of aerobic anoxygenic phototrophic bacteria in the coastal NW Mediterranean Sea as revealed by cell abundance, pigment concentration and pyrosequencing of pufM gene
Authors: Ferrera Isabel , Borrego Carles M. , Salazar Guillem , Gasol Josep M.
Published: September 2013

The abundance and diversity of aerobic anoxygenic phototrophs (AAPs) were studied for a year cycle at the Blanes Bay Microbial Observatory (NW Mediterranean) and their potential links to an array of environmental variables were explored. Cell numbers were low in winter and peaked in summer, showing a marked seasonality that positively correlated with day length and light at the surface. Bacteriochlorophyll a concentration, their light‐harvesting pigment, was only detected between April and October, and pigment cell quota showed large variations during this period. Pyrosequencing analysis of the pufM gene revealed that the most abundant operational taxonomic units (OTUs) were affiliated to phylogroup K (Gammaproteobacteria) and uncultured phylogroup C, although they were outnumbered by alphaproteobacterial OTUs in spring. Overall, richness was higher in winter than in summer, showing an opposite trend to abundance and day length. Clustering of samples by multivariate analyses showed a clear seasonality that suggests a succession of different AAP subpopulations over time. Temperature, chlorophyll a and day length were the environmental drivers that best explained the distribution of AAP assemblages. These results indicate that AAP bacteria are highly dynamic and undergo seasonal variations in diversity and abundance mostly dictated by environmental conditions as exemplified by light availability.
Inactivation of aPleurotus ostreatusversatile peroxidase‐encoding gene (mnp2) results in reduced lignin degradation
Authors: Salame Tomer M. , Knop Doriv , Levinson Dana , Mabjeesh Sameer J. , Yarden Oded , Hadar Yitzhak
Published: September 2013

Lignin biodegradation by white‐rot fungi is pivotal to the earth's carbon cycle. Manganese peroxidases (MnPs), the most common extracellular ligninolytic peroxidases produced by white‐rot fungi, are considered key in ligninolysis.Pleurotus ostreatus, the oyster mushroom, is a preferential lignin degrader occupying niches rich in lignocellulose such as decaying trees. Here, we provide direct, genetically based proof for the functional significance ofMnPtoP. ostreatusligninolytic capacity under conditions mimicking its natural habitat. When grown on a natural lignocellulosic substrate of cotton stalks under solid‐state culture conditions, gene and isoenzyme expression profiles of its shortMnPand versatile peroxidase (VP)‐encoding gene family revealed thatmnp2was predominately expressed.mnp2, encoding the versatile shortMnPisoenzyme 2 was disrupted. Inactivation ofmnp2resulted in three interrelated phenotypes, relative to the wild‐type strain: (i) reduction of 14% and 36% in lignin mineralization of stalks non‐amended and amended withMn2+, respectively; (ii) marked reduction of the bioconverted lignocellulose sensitivity to subsequent bacterial hydrolyses; and (iii) decrease in fungal respiration rate. These results may serve as the basis to clarify the roles of the various types of fungalMnPs andVPsin their contribution to white‐rot decay of wood and lignocellulose in various ecosystems.
The Sexuality-Assemblage: Desire, Affect, Anti-Humanism
Authors: Fox Nick J. , Alldred Pam
Published: September 2013

Two theoretical moves are required to resist the ‘humanist enticements’ associated with sexuality. Post-structuralism supplies the first, showing how the social produces culturally specific sexual knowledgeabilities. A second anti-humanist move is then needed to overturn anthropocentric privileging of the human body and subject as the locus of sexuality. In this paper we establish a language and landscape for a Deleuze-inspired anti-humanist sociology of sexuality that shifts the location of sexuality away from bodies and individuals. Sexuality in this view is an impersonal affective flow within assemblages of bodies, things, ideas and social institutions, which produces sexual (and other) capacities in bodies. Assemblages territorialize bodies' desire, setting limits on what it can do: this process determines the shape of sexuality, which is consequently both infinitely variable and typically highly restricted. We illustrate how this anti-humanist ontology may be applied to empirical data to explore sexuality-assemblages, and conclude by exploring the theoretical and methodological advantages and disadvantages of an anti-humanist assemblage approach to sexuality.
High‐Reliability Health Care: Getting There from Here
Authors: CHASSIN MARK R. , LOEB JEROD M.
Published: September 2013

Context

Despite serious and widespread efforts to improve the quality of health care, many patients still suffer preventable harm every day. Hospitals find improvement difficult to sustain, and they suffer “project fatigue” because so many problems need attention. No hospitals or health systems have achieved consistent excellence throughout their institutions. High‐reliability science is the study of organizations in industries like commercial aviation and nuclear power that operate under hazardous conditions while maintaining safety levels that are far better than those of health care. Adapting and applying the lessons of this science to health care offer the promise of enabling hospitals to reach levels of quality and safety that are comparable to those of the best high‐reliability organizations.

Methods

We combined the Joint Commission's knowledge of health care organizations with knowledge from the published literature and from experts in high‐reliability industries and leading safety scholars outside health care. We developed a conceptual and practical framework for assessing hospitals’ readiness for and progress toward high reliability. By iterative testing with hospital leaders, we refined the framework and, for each of its fourteen components, defined stages of maturity through which we believe hospitals must pass to reach high reliability.

Findings

We discovered that the ways that high‐reliability organizations generate and maintain high levels of safety cannot be directly applied to today's hospitals. We defined a series of incremental changes that hospitals should undertake to progress toward high reliability. These changes involve the leadership's commitment to achieving zero patient harm, a fully functional culture of safety throughout the organization, and the widespread deployment of highly effective process improvement tools.

Conclusions

Hospitals can make substantial progress toward high reliability by undertaking several specific organizational change initiatives. Further research and practical experience will be necessary to determine the validity and effectiveness of this framework for high‐reliability health care.
Establishment of lipiodol as a fertility treatment – Prospective study of the complete innovative treatment data set
Authors: Court K.A. , Dare A.J. , Weston‐Webb M. , Hadden W.E. , Sim R.G. , Johnson N.P.
Published: September 2013

Background

Our randomised controlled trial (RCT) found that a hysterosalpingogram (HSG) with the oil‐soluble contrast medium (OSCM) lipiodol improves pregnancy rates amongst couples with unexplained and endometriosis‐related infertility. These results were supported by the findings of our observational study of the first 100 women to undergo the procedure after it was offered as an innovative treatment in New Zealand from September 2003.

Aim

To further assess the safety and efficacy of lipiodol procedures and present together the complete data set of the procedures performed in our RCT and those performed as innovative procedures (n = 296) prior to it being offered as a standard fertility treatment.

Methods

Women with infertility underwent a therapeutic lipiodol procedure by HSG technique with fluoroscopy X‐ray screening. Primary outcomes were clinical pregnancy within six months of the procedure and live birth.

Results

The overall pregnancy rate for the 296 women was 40.2%. The live birth/ongoing pregnancy rate was 31.4%. The pregnancy rates for women under the age of 40 with endometriosis and unexplained infertility were 51.1 and 31.4%, respectively.

Conclusion

Lipiodol can now be considered a standard treatment for both unexplained and endometriosis‐related infertility. The precise mechanism behind the fertility‐enhancing effect of lipiodol has yet to be elucidated. This study supports a mechanism of effect on the endometrium with possible enhanced receptivity of the endometrium to embryo implantation.
Ethnographies of closed doors: conceptualising openness and closure in US immigration and military institutions
Authors: Belcher Oliver , Martin Lauren L
Published: September 2013

In this article, we discuss our experience conducting ethnographic and archival research on illiberal processes within nominally liberal states – in this case, the USA. We focus on two different institutional practices based on our respective fieldwork: (1) counterinsurgency training of civilian and military personnel in Indiana for deployment in southern Afghanistan and (2) immigration enforcement, particularly immigrant family detention. Building on Koch's (2013, this issue) argument for conceptualising closed contexts over il/liberal dichotomies, we analyse how liberal norms of open information, documentation and archiving function as governmental technologies. We argue that immigration and military agencies are not best understood as intentional, conspiratorial agencies bent on obscurity; rather, we show how a range of state and non‐state actors produce particular kinds of knowledge about US federal agency practices. By working through examples from our respective research projects, we show how seeking access to state agencies requires researchers' participation in the bounding of state and civil society. Rather than accept those boundaries, we argue that researchers in nominally liberal and illiberal states alike should pay close attention to how governmental technologies of openness and closure are woven together.
‘Cyanide kills!’ Environmental movements and the construction of environmental risk at Roşia Montană, Romania
Authors: Vesalon Lucian , Creţan Remus
Published: September 2013

This study examines the issue of environmental risk involved in a proposed gold‐mining project at Roşia Montană, Romania, as it was articulated in the discourses and strategies of the environmentalists protesting against it. We base our paper on the idea that environmental risk has a socially constructed horizon and that counter‐discourses on risk represent a fundamental contribution of the environmental protesters to the anti‐mining movement. This opposition can be integrated in a broader debate regarding the social and environmental costs of industrial development. The alternative conceptualisation of risk goes beyond narrowly defined ecological issues and applies to the more encompassing perspective of ‘communities at risk’. The anti‐mining movement's complex repertoire of contention and especially its challenging discourses on risk make it a unique development in post‐socialist environmentalism.
The Effects of Gentrification on Neighborhood Public Schools
Authors: Keels Micere , Burdick–Will Julia , Keene Sara
Published: September 2013

Gentrification is generally associated with improvements in neighborhood amenities, but we know little about whether the improvements extend to public schools. Using administrative data (from spring 1993 to spring 2004) from the third largest school district in the United States, we examine the relationships between gentrification and school–level student math and reading achievement, and whether changes in the composition of the student body account for any changes in achievement. After testing several alternative specifications of gentrification, we find that, in Chicago, gentrification has little effect on neighborhood public schools. Neighborhood public schools experience essentially no aggregate academic benefit from the socioeconomic changes occurring around them. Furthermore, they may even experience marginal harm, as the neighborhood skews toward higher income residents. For the individual student, starting first grade in a school located in a gentrifying neighborhood has no association with the relative growth rate of their test scores over their elementary school years.
The edentulous ridge expansion (ERE) technique an experimental study in the dog
Authors: Beolchini Marco , Lang Niklaus P. , Viganò Paolo , Bengazi Franco , Triana Barbara G. , Botticelli Daniele
Published: September 2013

Objective

To compare the healing and bony crest resorption at implants installed conventionally or applying an edentulous ridge expansion (ERE) technique in the maxilla.

Material and methods

In six Labrador dogs, the first and second maxillary incisors were extracted bilaterally. In the left side of the maxilla (Test), the flaps were elevated and the buccal plate of the alveoli and septa was removed. After 3 months of healing, partial‐thickness (split) flaps were dissected and the residual alveolar bone was exposed. In the right side of the maxilla, an implant was installed conventionally (Type IV; Control) while, in the left side, the ERE technique was adopted. Hence, an expansion of the buccal bony crest was obtained, and the implant was subsequently installed (Test). After 3 months of healing, biopsies were obtained and ground sections were prepared for histological analyses.

Results

A buccal vertical resorption of the bony crest of 2.2 ± 1.2 mm and 1.6 ± 0.7 mm was found at the test and control sites, respectively. The difference, however, did not reach statistical significance. The coronal level of osseointegration at the buccal aspect was located at 3.1 ± 1.0 mm and 2.2 ± 0.7 mm from the implant shoulder at the test and control sites, respectively, the difference being statistically significant. The mean values of the mineralized bone‐to‐implant contact (MBIC%) ranged from 43% to 48% at the buccal and lingual sites. No differences reached statistical significance.

Conclusions

Implants installed by applying an ERE technique may osseointegrate similarly to conventional implant installation. However, vertical and horizontal resorption of the displaced buccal bony wall occurred as well.
Comparison of clinical characteristics in patients with obesity hypoventilation syndrome and obese obstructive sleep apnea syndrome: a case‐control study
Authors: Basoglu Ozen K. , Tasbakan Mehmet Sezai
Published: September 2013

Introduction

Obesity hypoventilation syndrome (OHS) can be overlooked unless clinicians have a high index of suspicion. The present case‐control study aimed to compare characteristics of patients with OHS and obese obstructive sleep apnea syndrome (OSAS), and to identify determinants of hypercapnia in OSAS patients.

Methods

Demographic and anthropometric features, pulmonary function tests, blood gas analysis and sleep parameters of 59 OHS patients were compared to 295 body mass index‐matched OSAS patients.

Results

The rate of hypertension (67.8% vs 53.2%, respectively, P = 0.027) was higher in OHS than OSAS group. In OHS patients, FVC (%) (P < 0.0001), FEV1 (%) (P = 0.001) and PaO2 (P < 0.0001) were lower, whereas PaCO2 and HCO3 levels were increased (P < 0.0001). Daytime sleepiness was more frequent (89.8% vs 68.5%, respectively, P = 0.002), and Epworth sleepiness scores were higher (14.0 vs 11.9, respectively, P = 0.021) in OHS than OSAS patients. In polysomnography, lowest and mean SpO2 were decreased, and sleep time with SpO2<90% was increased in patients with OHS (P < 0.0001). Multivariate analysis showed that hypercapnia was associated independently with HCO3 (P < 0.0001) and daytime SaO2 (P = 0.003). Besides, HCO3 level ≥27 mEq/L had a sensitivity of 88.1% and specificity of 73.1%, and SaO2 ≤95% had a sensitivity of 64.4% and specificity of 73.9% for identifying OHS.

Conclusion

It was shown that OHS patients have increased rate of hypertension, daytime sleepiness and HCO3, and decreased lung functions and PaO2 levels than OSAS patients. The present results support that elevated bicarbonate levels and decreased oxygen saturations in obese OSAS patients should prompt clinicians to predict OHS.
Spiroergometric parameters at maximal exercise testing assessed functional respiratory impairment in asbestos‐induced fibrosis
Authors: Schneider Joachim , Arhelger Rolf , Funk Melanie
Published: September 2013

Introduction

Exercise intolerance is typical for asbestosis. We examined the correlation of spiroergometric parameters with severity of asbestosis according to the International Labour Office (ILO) classification. Patients were compared to a healthy control group.

Objectives

Nineteen consecutive male patients with compensated asbestosis and 24 healthy subjects were examined.

Methods

All participants underwent pulmonary functional testing including maximal cardiopulmonary exercise testing (CPET). Results were compared to those of healthy subjects; the correlation to disease status was investigated.

Results

Significantly lower VCin, FVC, FEV1, MEF50, TLC and PaO2 at rest (P < 0.001) were observed in asbestosis patients. Lower peak (weight‐related) work rate (WR, WR/kg), (weight‐related) oxygen uptake (V′O2, V′O2/kg), oxygen pulse (V′O2/hr), ventilation volume (V′E), carbon dioxide output (V′CO2) and blood lactate was associated (P < 0.001) with more severe asbestosis according to the ILO‐classification. Significant positive correlations (P < 0.001) were seen for alveolar‐arterial oxygen difference [P(A‐a)O2] and PaCO2. Multiple regression analysis revealed that asbestosis was the only significant factor associated with the spiroergometric parameters (P < 0.001). A reduction of V′O2, V′O2/kg, V′O2/hr, V′E, or V′CO2 at identical submaximal workload could neither be detected among the asbestosis severity nor in comparison to healthy subjects. Only the respiratory frequency was depending on severity of asbestosis.

Conclusions

The severity of asbestosis correlates with maximal WR, V′O2, V′O2/hr, V′E and gas exchange. At identical workload the discrimination between patients and controls was only possible concerning the respiratory frequency. For detection of limitations in asbestosis patients, maximal CPET is recommended.
The Energy Hot Potato and Governance of Value Chains: Power, Risk, and Organizational Adjustment in Intermediate Manufacturing Firms
Authors: Mulhall Rachel Ann , Bryson John R.
Published: September 2013

Cost competitiveness remains a significant element of firms' advantage in developed economies. Input costs, particularly nonlabor costs, are important factors underlying the competitive position of firms that are competing both domestically and internationally. Energy costs are becoming an increasing threat to the long‐term survival of firms because of their more volatile nature. The distinct geographic structure of energy prices combines both international markets and intranational policies and supply structures. It is vital to understand how firms manage the risk that is generated from such a complex input. This article explores the adjustment process of intermediate metal‐processing firms in the West MidlandsU.K. and their wider supply chain to the energy price risk and its interaction with existing long‐term adjustments to the pressure of globalization. Formal and informal relational agreements between customers and suppliers are identified as critical factors in determining the capacity of supplier firms to transfer energy price risks to their customers and to adapt to energy‐related pressures.
Factors Influencing the Twisting and Untwisting Properties of the Left Ventricle during Normal Pregnancy
Authors: Papadopoulou Elektra , Kaladaridou Anna , Agrios John , Matthaiou John , Pamboukas Constantinos , Toumanidis Savvas
Published: September 2013

Aims

During pregnancy, important hemodynamic changes occur, consistent with an increase in preload and decrease in afterload and systemic vascular resistance. The aim of the present study was to investigate the changes in left ventricular (LV) strain and rotational properties during the 3 trimesters of normal pregnancy and to examine the factors that drive these changes.

Methods and Results

Twenty‐seven pregnant women (29.7 ± 6.9 years) and 11 age‐matched nonpregnant controls (29.9 ± 5.4 years) were evaluated. Conventional echocardiography and two‐dimensional speckle tracking imaging were performed at 8–12 (1st trimester), 21–28 (2nd trimester), and 33–36 (3rd trimester) weeks of pregnancy. LV rotation, twist, untwisting rate, and circumferential strain were measured using the parasternal short‐axis views at basal and apical levels. Global longitudinal strain was calculated from the LV apical views. Peak LV twist and peak untwisting rate increased significantly in the 3rd trimester of normal pregnancy (13.48 ± 2.90°, 13.12 ± 3.30°, 16.83 ± 3.61°, P < 0.001; and −111.52 ± 23.54°/sec, −107.40 ± 26.58°/sec, −144.30 ± 45.14°/sec, P < 0.001; in the 1st, 2nd, and 3rd trimester, respectively). Global longitudinal and circumferential strain of the apex decreased significantly from the 2nd trimester. An independent association was found between the change in LV twist and the change in LV end‐systolic volume between the 1st and 3rd trimester. Peak untwisting rate at the 3rd trimester correlated significantly with peak twist and LV end‐diastolic volume.

Conclusions

During normal pregnancy, LV twist and peak untwisting rate increase in the 3rd trimester and correlate with end‐systolic and end‐diastolic volume, respectively. Circumferential strain of the apex and global longitudinal strain decrease from the 2nd trimester.
Echocardiographic and Lung Ultrasound Characteristics in Ambulatory Patients with Dyspnea or Prior Heart Failure
Authors: Platz Elke , Hempel Dorothea , Pivetta Emanuele , Rivero Jose , Solomon Scott D.
Published: September 2013

Purpose

Lung ultrasound (LUS) represents a novel, noninvasive method in the assessment of extravascular lung water. We investigated the utility of LUS in ambulatory subjects with dyspnea or prior heart failure (HF).

Methods

We studied 81 ambulatory subjects with HF history or dyspnea who underwent transthoracic echocardiography (TTE) with LUS of 8 zones. Subjects with heart transplantation or pulmonary conditions known to interfere with LUS were excluded. A reviewer blinded to the clinical data performed echocardiographic measurements and quantified B‐lines (reverberation artifacts arising from the pleural line).

Results

Of 81 subjects, 74 (91%) (median age 66 years, 39% men, median left ventricular ejection fraction [LVEF] 54%, 39% with prior HF) had adequate LUS images of all 8 zones and were included in the analysis. The number of B‐lines ranged from 0–12 (median 2). Increased B‐lines, analyzed by tertiles, were associated with larger left ventricular (LV) end‐diastolic (P = 0.036) and end‐systolic diameters (P = 0.026), septal wall thickness (P = 0.009), LV mass index (P = 0.001), left atrial (LA) volume index (P = 0.005), tricuspid regurgitation (TR) velocity (P = 0.005) and estimated pulmonary artery systolic pressure (PASP) (P = 0.003). In a secondary analysis associations between B‐lines (not grouped by tertiles) and LV mass index, LA volume index, TR velocity and PASP remained stable after adjustment for age, gender, BMI and HF history.

Conclusions

Sonographic B‐lines from LUS are related to measures of LV and LA structure and right ventricular pressure in ambulatory patients with dyspnea or prior HF. The added clinical and prognostic utility of this imaging modality in ambulatory patients warrants further investigation.
Determination of the Optimum Number of Cardiac Cycles to Differentiate Intra‐Pulmonary Shunt and Patent Foramen Ovale by Saline Contrast Two‐ and Three‐Dimensional Echocardiography
Authors: Bhatia Nirmanmoh , Abushora Mohannad Y. , Donneyong Macarius M. , Stoddard Marcus F.
Published: September 2013

Introduction

Patent foramen ovale (PFO) and intra‐pulmonary shunt (IPS) are potential causes of stroke. The most optimum cardiac cycle cutoff for bubbles to appear in the left heart on saline contrast transthoracic echocardiography (TTE) as criteria to differentiate the 2 entities is unknown.

Methods

Ninety‐five adult patients had saline contrast transesophageal echocardiography (TEE), two‐dimensional (2D) and 3DTTE. Sensitivity and specificity of each cardiac cycle as cutoff to differentiate a PFO and IPS were obtained.

Results

Transesophageal echocardiography showed IPS in 28 and PFO in 15 patients. If bubbles appeared in the left heart within the first 4 cardiac cycles (the 4th cardiac cycle rule) as compared to alternate cutoffs, a PFO was most accurately diagnosed by both 2D and 3DTTE. Bubbles appearing at or after the 5th cardiac cycle most accurately determined an IPS. 3D versus 2DTTE had a trend for a higher sensitivity (61% vs. 36%, P = 0.06), but similar specificity (94% vs. 91%) for IPS. Accuracy of 3DTTE was 84% and 2DTTE was 75% (P = 0.08) for IPS. For PFO, 2DTTE sensitivity (87%) and specificity (98%) did not differ (P = NS) from that of 3DTTE sensitivity (73%) and specificity (100%).

Conclusions

This study demonstrates for the first time that the 4th cardiac cycle rule differentiates PFO and IPS most optimally by 2D and 3DTTE. 3DTTE appears to have higher sensitivity for diagnosing IPS. These data suggest that 3DTTE is preferable when IPS is to be diagnosed. Both methods are similar for diagnosing PFO.
Discordant Doppler Right Heart Catheterization Pulmonary Artery Systolic Pressures: Importance of Pulmonary Capillary Wedge Pressure
Authors: Finkelhor Robert S. , Scrocco John D. , Madmani Mohammed , Rovner Aleksandr , Pillai Dilip
Published: September 2013

Background

Although the echo Doppler (D) estimation of pulmonary artery systolic pressure (PASP) was initially highly correlated with right heart catheterization (RHC), recent D‐RHC studies have questioned its accuracy. The aim of this study was to reevaluate this relationship and to determine possible explanations for disparate D‐RHC results.

Methods

We retrospectively identified all patients at one institution who underwent RHC and had an echocardiogram within the prior month. Echocardiographic and catheterization hemodynamic factors were evaluated by regression and Bland–Altman analysis.

Results

Of 69 patients, 52 (75.4%) had estimable D‐PASP. D‐RHC PASP r = 0.62 and 51.9% had a PASP difference >10 mmHg, comparable to other recent studies. The D‐RHC difference correlated with pulmonary capillary wedge pressure (PCWP) (r = −0.60, P < 0.001) and right atrial pressure (r = −0.43, P = 0.002). Multivariate analysis including wedge pressure improved the relation between D and RHC for PASP (r = 0.86). These results were little changed using only the respective RV‐RA pressure gradients from D and RHC.

Conclusion

Pulmonary capillary wedge pressure appears to be a significant covariate in the correlation between D and RHC PASP.
The Importance of Echocardiography in Transcatheter Aortic Valve Implantation
Authors: Bilen Emine , Sari Cenk , Durmaz Tahir , Keleş Telat , Bayram Nihal A. , Akçay Murat , Ayhan Hüseyin M. , Bozkurt Engin
Published: September 2013

Valvular heart diseases cause serious health problems in Turkey as well as in Western countries. According to a study conducted in Turkey, aortic stenosis (AS) is second after mitral valve disease among all valvular heart diseases. AS is frequently observed in elderly patients who have several cardiovascular risk factors and comorbidities. In symptomatic severe AS, surgical aortic valve replacement (AVR) is a definitive treatment. However, in elderly patients with left ventricular dysfunction and comorbidities, the risk of operative morbidity and mortality increases and outweighs the gain obtained from AVR surgery. As a result, almost one‐third of the patients with serious AS are considered ineligible for surgery. Transcatheter aortic valve implantation (TAVI) is an effective treatment in patients with symptomatic severe AS who have high risk for conventional surgery. Since being performed for the first time in 2002, with a procedure success rate reported as 95% and a mortality rate of 5%, TAVI has become a promising method. Assessment of vascular anatomy, aortic annular diameter, and left ventricular function may be useful for the appropriate selection of patients and may reduce the risk of complications. Cardiac imaging methods including 2D and 3D echocardiography and multidetector computed tomography are critical during the evaluation of suitable patients for TAVI as well as during and after the procedure. In this review, we describe the role of echocardiography methods in clinical practice for TAVI procedure in its entirety, i.e. from patient selection to guidance during the procedure, and subsequent monitoring.
Effects of release timing on migration behaviour and survival of hatchery‐reared Atlantic salmon smolts in a regulated river
Authors: Karppinen Petri , Jounela Pekka , Huusko Riina , Erkinaro Jaakko
Published: September 2013

In this study, 221 two‐year‐old hatchery‐reared salmon, Salmo salar, smolts were tagged with radio transmitters over a period of three consecutive years and released in the river in groups of 20–21 fish in various dates between late April and early June. Tagged smolts were tracked during their downstream migration in the lower 36‐km stretch of the regulated River Oulujoki, with the focus on the effects of release date, water temperature and river flow on migration behaviour and survival. The results indicate that release timing and river temperature have profound effects on the initiation of migration, swimming speed and survival of released S. salar smolts. Smolts released early in the spring in cold waters ceased migration after brief downstream movement and were vulnerable to predation, whereas the migration speed and survival rates increased markedly for smolts released later in the spring.
Seizure predisposition after perinatal hypoxia: Effects of subsequent age and of an epilepsy predisposing gene mutation
Authors: Leonard A. Soren , Hyder S. Nabeel , Kolls Brad J. , Arehart Eric , W. Ng Kim C. , Veerapandiyan Aravindhan , Mikati Mohamad A.
Published: September 2013

Purpose

There is a gap in our knowledge of the factors that modulate the predisposition to seizures following perinatal hypoxia. Herein, we investigate in a mouse model the effects of two distinct factors: developmental stage after the occurrence of the perinatal insult, and the presence of a seizure predisposing mutation.

Methods

Effects of age: P6 (postnatal day 6) mouse pups were subjected to acute hypoxia down to 4% O2 over the course of 45 min. Seizure susceptibilities to flurothyl‐induced seizures (single exposures) and to flurothyl kindling were determined at specific subsequent ages. Effects of mutation: Heterozygote mice, with deletion of one copy of the Kcn1a gene, subjected to P6 hypoxia were compared as adults to wild‐type mice with respect to susceptibility to a single exposure to flurothyl and to the occurrence of spontaneous seizures as detected by hippocampal electroencephalography (EEG) and video recordings.

Key Findings

Effects of age: As compared to controls, wild‐type mice exposed to P6 hypoxia had a shortened seizure latency in response to a single flurothyl exposure at P50, but not at P7 or P28 (p < 0.04). In addition, perinatal hypoxia at P6 enhanced the rate of development of flurothyl kindling performed at P28–38 (p < 0.03), but not at P7–17. Effects of mutation: Kcn1a heterozygous mice subjected to P6 hypoxia exhibited increased susceptibility to flurothyl‐induced seizures at P50 as compared to Normoxia heterozygote littermates, and to wild‐type Hypoxia and Normoxia mice. In addition, heterozygotes exposed to P6 hypoxia were the only group in which spontaneous seizures were detected during the period of long‐term monitoring (p < 0.027 in all comparisons).

Significance

Our data establish a mouse model of mild perinatal hypoxia in which we document the following: (1) the emergence, after a latent period, of increased susceptibility to flurothyl‐induced seizures, and to flurothyl induced kindling; and (2) an additive effect of a gene mutation to the seizure predisposing consequences of perinatal hypoxia, thereby demonstrating that a modifier (or susceptibility) gene can exacerbate the long‐term consequences of hypoxic injury.
Deep brain stimulation of the centromedian thalamic nucleus for the treatment of generalized and frontal epilepsies
Authors: Valentín Antonio , García Navarrete Eduardo , Chelvarajah Ramesh , Torres Cristina , Navas Marta , Vico Lelia , Torres Nerea , Pastor Jesus , Selway Richard , Sola Rafael G. , Alarcon Gonzalo
Published: September 2013

Purpose

Deep brain stimulation (DBS) of the thalamus is an emerging surgical option for people with medically refractory epilepsy that is not suitable for resective surgery, or in whom surgery has failed. Our main aim was to evaluate the efficacy of bilateral centromedian thalamic nucleus (CMN) DBS for seizure control in generalized epilepsy and frontal lobe epilepsy with a two‐center, single‐blind, controlled trial.

Methods

Participants were adults with refractory generalized or frontal lobe epilepsy. Seizure diaries were kept by patients/carers prospectively from enrollment. The baseline preimplantation period was followed by a control period consisting of a blind stimulation‐OFF phase of at least 3 months, a 3‐month blind stimulation‐ON phase, and a 6‐month unblinded stimulation‐ON phase. The control period was followed by an unblinded long‐term extension phase with stimulation‐ON in those patients in whom stimulation was thought to be effective.

Key Findings

Eleven patients were recruited at King's College Hospital (London, United Kingdom United Kingdom) and at University Hospital La Princesa (Madrid, Spain). Among the five patients with frontal lobe epilepsy, only one patient had >50% improvement in seizure frequency during the blind period. In the long‐term extension phase, two patients with frontal lobe epilepsy had >50% improvement in seizure frequency. All six patients with generalized epilepsy had >50% improvement in seizure frequency during the blind period. In the long‐term extension phase, five of the six patients showed >50% improvement in the frequency of major seizures (one became seizure free, one had >99% improvement, and three had 60–95% reduction in seizure frequency). Among patients with generalized epilepsy, the DBS implantation itself appears to be effective, as two patients remained seizure free during 12 and 50 months with DBS OFF, and the remaining four had 50–91% improvement in the initial 3 months with DBS OFF.

Significance

DBS implantation and stimulation of the CMN appears to be a safe and efficacious treatment, particularly in patients with refractory generalized epilepsy. CMN stimulation was not as effective in frontal lobe epilepsy, which requires further studies. DBS of the CMN should be considered as a treatment option, particularly in patients with refractory generalized epilepsy syndromes.