bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of focus, function, and features of shared knowledge on re-use in emergency management social media
Authors: Yates Dave
Published: October 2016

Purpose

The purpose of this study is to investigate how organizations use social media such as blogs to share and re-used knowledge during contingencies, disasters, and emergencies. The factors related to the knowledge itself – rather than the media – which lead to more and less re-use (particularly in the fast-paced and uncertain context of emergencies) are not well known.

Design/methodology/approach

Integrating theories of social media, knowledge management and mass communication, the author develops a model of the characteristics of knowledge (focus, function and features), characteristics of knowledge sharers and the user’s needs, which influence the extent to which knowledge is re-used.

Findings

A study of 645 blog posts revealed why some knowledge is re-used in emergencies more than other types of knowledge. Surprisingly, non-event-related knowledge is re-used more often than event-related knowledge, perhaps because users are less certain about how they would re-use non-event knowledge and, thus, are paradoxically more interested in what it might offer. Results also indicate several other factors which impact re-use.

Practical implications

Traditional mechanisms used to evaluate knowledge for reuse such as rank and organizational status are less important than the focus and function of the knowledge itself; they offer practitioners strategies for more efficient knowledge sharing during emergencies and identify opportunities for more effective employment of emergency management social media.

Originality/value

One of the first studies to dig deeper into factors of knowledge shared and re-used during emergencies, this research integrates several theoretical streams to explain why some knowledge is more valuable for re-use. It increases the understanding of knowledge sharing during disasters and offers strategies for development of knowledge systems for future emergencies.
Sustainability evolution in the Australian property market
Authors: Warren-Myers Georgia
Published: October 2016

Purpose

The relationship between sustainability and value in property has been a major area of investigation over the past decade. However, in spite of the extant literature and research, the connections made by valuers in practice of the value relationship are still unresolved. The purpose of this paper is to investigate, in the Australian context, valuers’ perception of the relationship between sustainability and value; and their experience and knowledge of sustainability in valuation practice.

Design/methodology/approach

The research investigates valuers’ perception and knowledge of sustainability and its inclusion in valuation practice in Australia. The approach uses a longitudinal survey of valuers from 2007 to 2015 tracking valuers’ knowledge, understanding, inclusion of sustainability reporting and the perceptions of the relationship between sustainability and market value.

Findings

This paper presents findings from a longitudinal survey that has been conducted in Australia since 2007, identifying changes between 2007, the height of the property market and sustainability engagement prior to the global financial crisis, and the subsequent years to 2015. The growth of sustainability in the property market is significant, however, valuers’ knowledge and reporting on sustainability is not demonstrating the same level of development. As a result, this is inhibiting valuers reporting on sustainability and has implications for practice and treatment of market values.

Practical implications

This research highlights the need to examine how to assist valuers to more rapidly develop knowledge and experience to reflect the implications of change in practice. Current approaches being developed in the UK and Europe, like the introduction of RenoValue professional development programs and guidance documents, to assist valuers to develop their knowledge needs to be implemented in the Australian environment as current approaches are inadequate, and steps need to be taken in order to assist their development of knowledge and experience as the market demonstrates growth and acceptance of sustainability. This research identifies the need to re-examine how professional development is undertaken and knowledge developed by those practicing in the profession in Australia.

Originality/value

This longitudinal survey is the only research that has spanned a substantial period of time attempting to ascertain valuers’ perception of the relationship between sustainability and value; and attempts to track the knowledge development of valuers in the context of sustainability. The findings identify how the market is developing and adhering to a product model development theory, however, also identifies more fundamental issues and implications for valuation praxis, in the development of knowledge and ability of valuers to adapt to change and reflect these valuations.
Valuing specialised property using the DCF profits method
Authors: Jansen van Vuuren David
Published: October 2016

Purpose

The purpose of this paper is twofold: primary, to argue that the profits method, specifically a discounted cash flow (DCF)-based profits method, should be the preferred method of valuation when valuing specialised property. Secondary, to make technical recommendations in the application of the method.

Design/methodology/approach

Literature was reviewed on the theory of the profits method as well as physical valuations performed in practice. Improvements for the profits method are suggested from the review of six valuations conducted in South Africa in the specialised property sectors. A qualitative approach is followed in the research as broad principles are extracted from the valuation reports as implications and improvements for the profits method.

Findings

The profits method is more flexible and sophisticated than the cost approach in taking into account systematic and unsystematic risk. The profits method is more accurate than the cost approach in delivering a true reflection of the value of specialised property for any purpose but specifically for mortgage lending purposes and reduces the credit exposure risk of financial institutions. It also decreases pricing inefficiencies to be exploited by buyers and sellers.

Practical implications

Three improvements to the profits method are suggested. First, revenue could be forecasted based on a probability-weighted approach. Second, a modified capitalisation rate is suggested to the capitalisation rate formula in the calculation of G. Third, a market rental aggregation anchoring and judgement-based approach is suggested as rationale for determining the hypothetical rental split.

Originality/value

There seems to be a general lack in literature on the profits method of valuation and its application to specialised properties, specifically a DCF-based approach, with this paper being a technical contribution to the body of knowledge on this topic.
The internal rate of return (IRR): projections, benchmarks and pitfalls
Authors: Patrick Michael , French Nick
Published: October 2016

Purpose

The purpose of this paper is to discuss the use of the internal rate of return (IRR) as a principal measure of performance of investments and to highlight some of the weaknesses of the IRR in evaluating investments in this way.

Design/methodology/approach

This Education Briefing is an overview of the limitations of the IRR in making capital budgeting decisions. It is illustrated with a number of counter-intuitive examples.

Findings

The advantage of the IRR is that it is, on the surface, a wonderfully simple benchmark. One figure that tells a story. But, the disadvantage is that if used in isolation the IRR can give misleading results when used to assess investment proposals.

Practical implications

The IRR should be used in conjunction with other analyses to appraise projects, so that the user can determine its veracity in the context of other benchmarks. This context is particularly important when assessing investments with unusual cash flows.

Originality/value

This is a review of existing models.
Laughing bonds
Authors: Navarro Jorge , del Moral Raquel , Marijuán Pedro C.
Published: October 2016

Purpose

The purpose of this paper is to present a new core hypothesis on laughter. It has been built by putting together ideas from several disciplines: neurodynamics, evolutionary neurobiology, social networks, and communication studies. The hypothesis focusses on the social nature of laughter and contributes to ascertain its evolutionary origins in connection with the cognitive and social-emotional functions it performs.

Design/methodology/approach

An in-depth examination of laughter in the social communication context and along the life cycle of the individual is performed. This instinctive behaviour that appears as a “virtual”, non-physical form of “grooming” would serve as a bond-making instrument in human groups. Further, the neurodynamic events underlying laughter production – and particularly the form of the neural entropy gradients – are congruent with a sentic hypothesis about the different emotional contents of laughter and their specific effects on bonding dynamics.

Findings

The new behavioural and neurodynamic tenets introduced about this unusual sound feature of our species justify the ubiquitous presence it has in social interactions at large and along the life cycle of the individual. Laughter, far from being a curious evolutionary relic or a rather inconsequential innate behaviour, should be considered as a highly efficient tool for inter-individual problem solving and for maintenance of social bonds.

Originality/value

Laughter, the authors would conclude, has been evolutionarily kept and augmented as an optimized tool for unconscious cognitive-emotional problem solving, and at the same time as a useful way to preserve the essential fabric of social bonds in close-knit groups and within human societies at large.
Incremental kernel fuzzy c-means with optimizing cluster center initialization and delivery
Authors: Jiao Runhai , Liu Shaolong , Wen Wu , Lin Biying
Published: October 2016

Purpose

The large volume of big data makes it impractical for traditional clustering algorithms which are usually designed for entire data set. The purpose of this paper is to focus on incremental clustering which divides data into series of data chunks and only a small amount of data need to be clustered at each time. Few researches on incremental clustering algorithm address the problem of optimizing cluster center initialization for each data chunk and selecting multiple passing points for each cluster.

Design/methodology/approach

Through optimizing initial cluster centers, quality of clustering results is improved for each data chunk and then quality of final clustering results is enhanced. Moreover, through selecting multiple passing points, more accurate information is passed down to improve the final clustering results. The method has been proposed to solve those two problems and is applied in the proposed algorithm based on streaming kernel fuzzy c-means (stKFCM) algorithm.

Findings

Experimental results show that the proposed algorithm demonstrates more accuracy and better performance than streaming kernel stKFCM algorithm.

Originality/value

This paper addresses the problem of improving the performance of increment clustering through optimizing cluster center initialization and selecting multiple passing points. The paper analyzed the performance of the proposed scheme and proved its effectiveness.
Comparative study on textual data set using fuzzy clustering algorithms
Authors: Sadika Rjiba , Soltani Moez , Benammou Saloua
Published: October 2016

Purpose

The purpose of this paper is to apply the Takagi-Sugeno (T-S) fuzzy model techniques in order to treat and classify textual data sets with and without noise. A comparative study is done in order to select the most accurate T-S algorithm in the textual data sets.

Design/methodology/approach

From a survey about what has been termed the “Tunisian Revolution,” the authors collect a textual data set from a questionnaire targeted at students. Five clustering algorithms are mainly applied: the Gath-Geva (G-G) algorithm, the modified G-G algorithm, the fuzzy c-means algorithm and the kernel fuzzy c-means algorithm. The authors examine the performances of the four clustering algorithms and select the most reliable one to cluster textual data.

Findings

The proposed methodology was to cluster textual data based on the T-S fuzzy model. On one hand, the results obtained using the T-S models are in the form of numerical relationships between selected keywords and the rest of words constituting a text. Consequently, it allows the authors to interpret these results not only qualitatively but also quantitatively. On the other hand, the proposed method is applied for clustering text taking into account the noise.

Originality/value

The originality comes from the fact that the authors validate some economical results based on textual data, even if they have not been written by experts in the linguistic fields. In addition, the results obtained in this study are easy and simple to interpret by the analysts.
Evaluation of thiol-ene photo-curable resins using in rapid prototyping
Authors: Zhou Jian , Zhang Qiuyu , Zhang Hepeng , Tan Jiaojun , Chen Shaojie , Liu Qing , Ma Mingliang , Xin Tiejun
Published: October 2016

Purpose

The purpose of this paper is to evaluate the properties of several thiol-acrylate photosensitive systems and compare with corresponding acrylate free-radical systems. The potential stereolithography applications of thiol–ene photosensitive systems are also discussed.

Design/methodology/approach

In the both thiol–ene and acrylate free-radical photosensitive systems, various key performances were characterized. The function group conversions were characterized by real-time Fourier transform infrared spectroscopy. The tension strength was determined according to the standard ASTM D638-2003, the flexible strength was determined according to ASTM D790-07 and the hardness was measured according to ASTM D2240-05. The volume shrinkage was measured by dilatometer method. The glass transition temperature was analyzed by differential scanning calorimeter.

Findings

As adding mercapto propionates into acrylate system, the inhibition of polymerization by oxygen was controlled and the flexible performance was improved. In addition, the photosensitive resin showed better tension strength, higher elongation at break and lower volume shrinkage. Among the four mercapto propionates, rigid TEMPIC showed most obvious affect, followed hexa-functional DPMP, tetra-functional PETMP and tri-functional TMMP.

Originality/value

Although the thiol–ene photosensitive resin has unmatched advantages in performance, there are no reports on the thiol–ene photosensitive resin in the stereolithography application. In this study, thiol–ene photopolymerization material was first tentatively implemented in stereolithography area. Several critical performance parameters were compared between thiol–ene and acrylate free-radical photosensitive systems.
SLM additive manufacture of H13 tool steel with conformal cooling and structural lattices
Authors: Mazur Maciej , Leary Martin , McMillan Matthew , Elambasseril Joe , Brandt Milan
Published: October 2016

Purpose

Additive manufacture (AM) such as selective laser melting (SLM) provides significant geometric design freedom in comparison with traditional manufacturing methods. Such freedom enables the construction of injection moulding tools with conformal cooling channels that optimize heat transfer while incorporating efficient internal lattice structures that can ground loads and provide thermal insulation. Despite the opportunities enabled by AM, there remain a number of design and processing uncertainties associated with the application of SLM to injection mould tool manufacture, in particular from H13/DIN 1.2344 steel as commonly used in injection moulds. This paper aims to address several associated uncertainties.

Design/methodology/approach

A number of physical and numerical experimental studies are conducted to quantify SLM-manufactured H13 material properties, part manufacturability and part characteristics.

Findings

Findings are presented which quantify the effect of SLM processing parameters on the density of H13 steel components; the manufacturability of standard and self-supporting conformal cooling channels, as well as structural lattices in H13; the surface roughness of SLM-manufactured cooling channels; the effect of cooling channel layout on the associated stress concentration factor and cooling uniformity; and the structural and thermal insulating properties of a number of structural lattices.

Originality/value

The contributions of this work with regards to SLM manufacture of H13 of injection mould tooling can be applied in the design of conformal cooling channels and lattice structures for increased thermal performance.
Shaping ceramics through indirect selective laser sintering
Authors: Deckers Jan Patrick , Shahzad Khuram , Cardon Ludwig , Rombouts Marleen , Vleugels Jozef , Kruth Jean-Pierre
Published: October 2016

Purpose

The purpose of this paper is to compare different powder metallurgy (PM) processes to produce ceramic parts through additive manufacturing (AM). This creates the potential to rapidly shape ceramic parts with an almost unlimited shape freedom. In this paper, alumina (Al2O3) parts are produced, as Al2O3is currently the most commonly used ceramic material for technical applications.

Design/methodology/approach

Variants of the following PM route, with indirect selective laser sintering (indirect SLS) as the AM shaping step, are explored to produce ceramic parts: powder synthesis, indirect SLS, binder removal and furnace sintering and alternative densification steps.

Findings

Freeform-shaped Al2O3parts with densities up to approximately 90 per cent are obtained.

Research limitations/implications

The resulting Al2O3parts contain inter-agglomerate pores. To produce higher-quality ceramic parts through indirect SLS, these pores should be avoided or eliminated.

Originality/value

The research is innovative in many ways. First, composite powders are produced using different powder production methods, such as temperature-induced phase separation and dispersion polymerization. Second, four different binder materials are investigated: polyamide (nylon-12), polystyrene, polypropylene and a carnauba wax – low-density polyethylene combination. Further, to produce ceramic parts with increased density, the following densification techniques are investigated as additional steps of the PM process: laser remelting, isostatic pressing and infiltration.
Fast–slow life history is correlated with individual differences in movements and prey selection in an aquatic predator in the wild
Authors: Nakayama Shinnosuke , Rapp Tobias , Arlinghaus Robert
Published: October 2016

Fast and slow life histories are proposed to covary with consistent individual differences in behaviour, but little is known whether it holds in the wild, where individuals experience natural fluctuations of the environment.

We investigated whether individual differences in behaviour, such as movement traits and prey selection, are linked to variation in life‐history traits in Eurasian perch (Perca fluviatilis) in the wild.

Using high‐resolution acoustic telemetry, we collected the positional data of fish in a whole natural lake and estimated individual movement traits by fitting a two‐state correlated random walk model. Prey selection was inferred from stable isotope analysis using scale samples. Life‐history traits were estimated by fitting a biphasic growth model to an individual growth trajectory back‐calculated from scale samples.

Life‐history traits were correlated with behavioural traits such as movements and prey selection. Individuals with higher reproductive effort were found to switch more frequently between active and inactive modes and show greater reliance on prey from pelagic pathways (indicated by lower δ13C). Further, individuals with faster juvenile growth were found to stay active for a longer time during the adult stage.

Our results demonstrate the link between individual behavioural differences and fast–slow life‐history traits under ecologically relevant conditions.
Forest diversity promotes individual tree growth in central European forest stands
Authors: Chamagne Juliette , Tanadini Matteo , Frank David , Matula Radim , Paine C. E. Timothy , Philipson Christopher D. , Svátek Martin , Turnbull Lindsay A. , Volařík Daniel , Hector Andy
Published: October 2016

Most experimental evidence on the relationship between biodiversity and ecosystem functioning comes from ecosystems with fast‐growing plants, such as grasslands. Although forests provide essential ecological services, they have been less well investigated.

We used dendrochronology to compare the tree radial growth rates of four important timber species in replicated, spatially mapped stands that differed in tree composition and diversity within a central European managed forest.

Growth rates differed among species but were largely unaffected by the density of neighbouring trees.

Increasing stand diversity enhanced individual growth rates, after accounting for the effects of tree density and size. These increases were statistically indistinguishable among the four species. In contrast, the effects of stand and neighbourhood species composition on growth rates were non‐significant.

Policy implications. Our study of long‐established central European forest stands revealed levels of tree diversity can be increased in managed forests, with the potential for modest increases in tree growth rates. These results suggest that in addition to the biodiversity and risk mitigation benefits associated with shifting practices away from monoculture management, increased carbon sequestration and yields in mature forests are likely to be realized. Our results suggest that it is possible to increase forest diversity with little or no costs to production and even with the potential for modest increases in tree growth rates.
Sound of silence: the beauvericin cluster in Fusarium fujikuroi is controlled by cluster‐specific and global regulators mediated by H3K27 modification
Authors: Niehaus Eva‐Maria , Studt Lena , von Bargen Katharina W. , Kummer Wiebke , Humpf Hans‐Ulrich , Reuter Gunter , Tudzynski Bettina
Published: October 2016

In this study, we compared the secondary metabolite profile of Fusarium fujikuroi and the histone deacetylase mutant ΔHDA1. We identified a novel peak in ΔHDA1, which was identified as beauvericin (BEA). Going in line with a 1000‐fold increased BEA production, the respective non‐ribosomal peptide synthetase (NRPS)‐encoding gene (BEA1), as well as two adjacent genes (BEA2‐BEA3), were significantly up‐regulated in ΔHDA1 compared to the wild type. A special role was revealed for the ABC transporter Bea3: deletion of the encoding gene resulted in significant up‐regulation of BEA1 and BEA2 and drastically elevated product yields. Furthermore, mutation of a conserved sequence motif in the promoter of BEA1 released BEA repression and resulted in elevated product levels. Candidate transcription factors (TFs) that could bind to this motif are the cluster‐specific TF Bea4 as well as a homolog of the global mammalian Kruppel‐like TF Yin Yang 1 (Yy1), both acting as repressors of BEA biosynthesis. In addition to Hda1, BEA biosynthesis is repressed by the activity of the H3K27 methyltransferase Kmt6. Consistently, Western blot analyses revealed a genome‐wide enrichment of H3K27 acetylation (H3K27ac) in the ΔHDA1 and KMT6 knock‐down mutants. Subsequent chromatin immunoprecipitation (ChIP) experiments showed elevated H3K27ac modification levels at the BEA cluster.
An everyday affair: deciphering the sociological significance of women’s attitudes towards infidelity
Authors: van Hooff Jenny
Published: October 2016

This article draws on interview material to examine the recent hardening of attitudes towards infidelity. The visibility and apparent frequency of both consensual non-monogamy, as well as more common covert experiences, would suggest a challenge to dominant mononormative assumptions about the feasibility of lifelong monogamy. However, infidelity remains the lone area of adult sexual practice that is disapproved of under any circumstances. I argue that increasing hostility towards affairs is located in the discursive context of the ‘specialness’ of sex and the centrality of trust and communication to constructions of contemporary relationships. With the monogamous sexual couple at the centre of personal life, infidelity is regarded as a particular threat, revealing wider limitations to claims about the extent to which relationships have been detraditionalized.
In situ simulation in emergency medicine: Moving beyond the simulation lab
Authors: Petrosoniak Andrew , Auerbach Marc , Wong Ambrose H , Hicks Christopher M
Published: October 2016

In situ simulation (ISS), a point of care training strategy that occurs within the patient care environment involving actual healthcare team members, provides additional benefits to centre‐based simulation. ISS can serve several roles within emergency medicine (EM): improves provider/team performance, identifies and mitigates threats to patient safety and improves systems and infrastructure. The effective use of ISS fosters inter‐professional team training and a culture of safety essential for high performance EM teams and resilient systems. Using a case example, this article addresses the uses of ISS in EM, strategies for implementation and mitigation strategies for ED‐specific challenges.
Effect of Fermentation Temperature on the Volatile Composition of Kimchi
Authors: Hong Sang Pil , Lee Eun Joo , Kim Young Ho , Ahn Dong Uk
Published: October 2016

This study was conducted to evaluate the effect of fermentation temperature on the volatile composition in Kimchi. Kimchi was fermented at 2 temperature conditions (4 and 20 °C). Volatile compounds of Kimchi samples were analyzed during the fermentation periods using the dynamic headspace gas chromatography‐mass spectrometry method. The optimum ripening time for the Kimchi fermented at 4 °C was 35 d, and that of 20 °C was 2 d. The pH at the optimum ripening time was 4.97 and 4.41, and the titratable acidity was 0.59% and 0.76% for the Kimchi fermented at 4 and 20 °C, respectively. Forty different types of volatile compounds, including alcohol, aldehyde, ester, and sulfur compounds, were identified. The Kimchi fermented at 20 °C produced greater amounts of volatile compounds than that at 4 °C. The amounts of most volatiles increased as the fermentation time increased, but those of aldehydes decreased rapidly during both 4 and 20 °C fermentation. Organic acids, ester, and nitriles were detected only in Kimchi fermented at 20 °C. The amounts of dimethyl disulfide, methyl‐2‐propenyl disulfide, and di‐2‐propenyl disulfide produced from the Kimchi fermented at 20 °C were more than 2‐times of those at 4 °C. Therefore, it is concluded that the strong pungent odor of Kimchi fermented at 20° C is probably due to the high amount of organic acids (low pH) and sulfur compounds (dimethyl disulfide, methyl‐2‐propenyl disulfide, and di‐2‐propenyl disulfide) between the 2 Kimchi.
External finance and dividend policy: a twist by financial constraints
Authors: He Zhong , Chen Xiaoyan , Huang Wei , Pan Rulu , Shi Jing
Published: October 2016

This study assesses distorting effect of financial constraints on the inverse relationship between internal and external finance by examining impact of an exogenous financing shock (i.e. a regulation released in China in 2008) on dividend policies in a quasi‐natural experimental setting. Our result shows that in the absence of the regulation, the inverse relationship holds. However, the relation is twisted by the 2008 regulation. Compared with unconstrained firms, financially constrained firms are more willing to pay dividends and are more restrained to reduce cash dividends after the regulation, despite the fact that their external financing capacities are further constrained.
In aid of (re)discovered species: maximizing conservation insights from minimal data
Authors: Brichieri‐Colombi T. A. , McPherson J. M. , Sheppard D. J. , Moehrenschlager A.
Published: October 2016

New species discoveries or the rediscovery of species once considered extinct or extirpated is good news, and yet prospects for long‐term survival may be bleak if remnant populations are small and isolated. Because (re)discovered species are commonly rare or cryptic, data to inform appropriate conservation actions are usually sparse. We demonstrate how to make the most of available data, using the recent rediscovery in Ghana of sitatunga Tragelaphus spekei as an illustrative case study. Sitatunga were thought extinct in Ghana for over 50 years, but were ‘rediscovered’ by science in Avu Lagoon in 1998. Little is known about this species, especially West African populations, given its cryptic nature and inaccessible wetland habitat. Our approach to maximizing insights given limited data first paired observations of occurrence with landscape characteristics derived from open‐access remote sensing data, creating the first ever habitat suitability model for sitatunga. This model then served to: (1) elucidate habitat preferences; (2) assess possible existence and connectivity of remnant populations elsewhere in Ghana; and (3) estimate maximum total and effective population size. Moreover, the timing of occurrence sightings provided insights into behavior. Sitatunga sightings were rare, heavily male‐biased and mostly occurred between 6 pm and 6 am. Suitable habitat was limited, suggesting that habitat in and near Avu Lagoon is insufficient to ensure long‐term population viability, and the existence of other, connected populations in Ghana is improbable. Without continued protection, and possibly additional interventions to augment population numbers or gene flow, the sitatunga in Avu Lagoon will likely go extinct. Our case study demonstrates the conservation challenges associated with the rediscovery of relict populations, and the utility of applying tools such as habitat suitability models to sparse data. Moreover, our research stresses the need to implement immediate conservation action upon species (re)discoveries to prevent (regional) extinction.
Ethnic Networks
Authors: Larson Jennifer M. , Lewis Janet I.
Published: October 2016

Active research on a wide range of political contexts centers on ethnicity's role in collective action. Many theories posit that information flows more easily in ethnically homogeneous areas, facilitating collective action, because social networks among coethnics are denser. Although this characterization is ubiquitous, little empirical work assesses it. Through a novel field experiment in a matched pair of villages in rural Uganda, this article directly examines word‐of‐mouth information spread and its relationship to ethnic diversity and networks. As expected, information spread more widely in the homogeneous village. However, unexpectedly, the more diverse village's network is significantly denser. Using unusually detailed network data, we offer an explanation for why network density may hamper information dissemination in heterogeneous areas, showing why even slight hesitation to share information with people from other groups can have large aggregate effects.
Contamination of single‐use bronchoscopes in critically ill patients
Authors: McGrath B. A. , Ruane S. , McKenna J. , Thomas S.
Published: October 2016

Disposable bronchoscopes such as the Ambu aScopeTM 3 are marketed as ‘single use’ The risks of contamination from prolonged device storage before possible re‐use are unknown. Following clinical bronchoscopy in patients whose lungs were mechanically ventilated, 20 aScopeTM 3's bronchoscopes received a standard ‘social clean’ and were then stored. Subsequent paired saline flush and swab samples were taken at time zero, and at 24 h and 48 h. Positive microbiological cultures were obtained from at least one time point from 16 of the 20 bronchoscopes. Pathogens considered at high risk of causing pneumonia were isolated from seven bronchoscopes, with significant quantities from six of them. Our study demonstrates that aScopeTM 3's should not be re‐used on the same patient, as clinically significant growth of micro‐organisms occurs frequently, despite adequate social cleaning. Culture of bronchoscopes themselves may be a potentially useful diagnostic tool in the context of pulmonary infection. Our data make it clear that these devices are single use and not single patient use.
Cerebral oxygenation during changes in vascular resistance and flow in patients on cardiopulmonary bypass – a physiological proof of concept study
Authors: Sperna Weiland N. H. , Brevoord D. , Jöbsis D. A. , de Beaumont E. M. F. H. , Evers V. , Preckel B. , Hollmann M. W. , van Dieren S. , de Mol B. A. J. M. , Immink R. V.
Published: October 2016

Despite a rise in blood pressure, cerebral oxygenation decreases following phenylephrine administration, and we hypothesised that phenylephrine reduces cerebral oxygenation by activating cerebral α1 receptors. We studied patients on cardiopulmonary bypass during constant flow. Phenylephrine raised mean arterial pressure (α1‐mediated) from mean (SD) 69 (8) mmHg to 79 (8) mmHg; p = 0.001, and vasopressin raised mean arterial pressure (V1 mediated) from 69 (8) mmHg to 83 (6) mmHg; p = 0.001. Both drugs elicited a comparable decrease in cerebral oxygenation from 61 (7)% to 60 (7)%; p = 0.023 and 61 (8)% to 59 (8)%; p = 0.022, respectively. This implies that after phenylephrine or vasopressin administration, cerebral oxygenation declines as a result of cerebral vasoconstriction, due to either both cerebral α1 and V1 receptors being equipotentially activated or to an intrinsic myogenic mechanism of cerebral vasculature in reaction to blood pressure elevation.
Polymorphisms in ABCB1 and CYP19A1 genes affect anastrozole plasma concentrations and clinical outcomes in postmenopausal breast cancer patients
Authors: Gervasini Guillermo , Jara Carlos , Olier Clara , Romero Nuria , Martínez Ruth , Carrillo Juan Antonio
Published: October 2016

Aims

Anastrozole, an aromatase inhibitor widely used in breast cancer, has recently been indicated to be a P‐glycoprotein (ABCB1) substrate. We have aimed to determine whether ABCB1 single‐nucleotide polymorphisms (SNPs) can affect anastrozole plasma concentrations in these patients. In addition, we assessed the impact of SNPs in CYP19A1 and TCL1A on the development of arthralgia and cancer recurrence in our series.

Methods

This study included 110 postmenopausal women with hormone receptor‐positive breast cancer. Anastrozole plasma levels were determined by a liquid chromatography–electrospray ionization–quadrupole‐time‐of‐flight mass spectrometry system. Patients were genotyped for SNPs in the ABCB1, TCL1A and CYP19A1 genes to search for associations with pharmacokinetic and pharmacodynamics parameters using logistic regression models.

Results

Anastrozole concentrations showed an almost nine‐fold interindividual variability (mean 26.95 ± 11.91 ng ml−1). The ABCB1 2677‐TT genotype was associated with higher plasma levels (32.22 ± 12.82 vs. 25.86 ± 11.56 ng ml−1 for GG/GT subjects; 95% confidence interval: –12.3 to –0.40), whilst the 3435‐TT genotype showed a protective effect on the risk of arthralgia (odds ratio = 0.32 [0.11–0.89]; P = 0.029). The CYP19A1 rs1008805 GG genotype was strongly and inversely associated with arthralgia (odds ratio = 0.24 [0.09–0.65], P = 0.004); however, SNPs near the TCL1A gene were not linked to this adverse effect. None of the patients who had cancer recurrence harboured the CYP19A1 rs727479 AA genotype, which, in contrast, was present in 38% of patients who did not relapse (P for trend = 0.031).

Conclusion

Our findings indicate that variability in anastrozole plasma levels may be attributable to the status of the ABCB1 gene locus. Furthermore, genetic variants in CYP19A1 were associated with arthralgia and cancer recurrence in our patients.
The era of comparable life expectancy between thalassaemia major and intermedia: Is it time to revisit the major‐intermedia dichotomy?
Authors: Vitrano Angela , Calvaruso Giuseppina , Lai Eliana , Colletta Grazia , Quota Alessandra , Gerardi Calogera , Concetta Rigoli Luciana , Pitrolo Lorella , Cuccia Liana , Gagliardotto Francesco , Filosa Aldo , Caruso Vincenzo , Argento Crocetta , Campisi Saveria , Rizzo Michele , Prossomariti Luciano , Fidone Carmelo , Fustaneo Maria , Di Maggio Rosario , Maggio Aurelio
Published: October 2016

In the last few decades, the life expectancy of regularly transfused β‐thalassaemia major (TM) patients has dramatically improved following the introduction of safe transfusion practices, iron chelation therapy, aggressive treatment of infections and improved management of cardiac complications. How such changes, especially those attributed to the introduction of iron chelation therapy, improved the survival of TM patients to approach those with β‐thalassaemia intermedia (TI) remains unknown. Three hundred and seventy‐nine patients with TM (n = 284, dead 40) and TI (n = 95, dead 13) were followed retrospectively since birth until 30 June 2015 or death. Kaplan‐Meir curves showed statistically significant differences in TM and TI survival (P < 0·0001) before the introduction of iron chelation in 1965, which were no longer apparent after that date (P = 0·086), reducing the Hazard Ratio of death in TM compared to TI from 6·8 [95% confidence interval (CI) 2·6–17·5] before 1965 to 2·8 (95% CI 0·8–9·2). These findings suggest that, in the era of iron chelation therapy and improved survival for TM, the major‐intermedia dichotomy needs to be revisited alongside future directions in general management and prevention for both conditions.
Impaired oligodendroglial turnover is associated with myelin pathology in focal cortical dysplasia and tuberous sclerosis complex
Authors: Scholl Theresa , Mühlebner Angelika , Ricken Gerda , Gruber Victoria , Fabing Anna , Samueli Sharon , Gröppel Gudrun , Dorfer Christian , Czech Thomas , Hainfellner Johannes A. , Prabowo Avanita S. , Reinten Roy J. , Hoogendijk Lisette , Anink Jasper J. , Aronica Eleonora , Feucht Martha
Published: October 2016

Conventional antiepileptic drugs suppress the excessive firing of neurons during seizures. In drug‐resistant patients, treatment failure indicates an alternative important epileptogenic trigger. Two epilepsy‐associated pathologies show myelin deficiencies in seizure‐related brain regions: Focal Cortical Dysplasia IIB (FCD) and cortical tubers in Tuberous Sclerosis Complex (TSC). Studies uncovering white matter‐pathology mechanisms are therefore urgently needed to gain more insight into epileptogenesis, the propensity to maintain seizures, and their associated comorbidities such as cognitive defects. We analyzed epilepsy surgery specimens of FCD IIB (n = 22), TSC (n = 8), and other malformations of cortical development MCD (n = 12), and compared them to autopsy and biopsy cases (n = 15). The entire lesional pathology was assessed using digital immunohistochemistry, immunofluorescence and western blotting for oligodendroglial lineage, myelin and mTOR markers, and findings were correlated to clinical parameters. White matter pathology with depleted myelin and oligodendroglia were found in 50% of FCD IIB and 62% of TSC cases. Other MCDs had either a normal content or even showed reactive oligodendrolial hyperplasia. Furthermore, myelin deficiency was associated with increased mTOR expression and the lower amount of oligodendroglia was linked with their precursor cells (PDGFRa). The relative duration of epilepsy (normalized to age) also correlated positively to mTOR activation and negatively to myelination. Decreased content of oligodendroglia and missing precursor cells indicated insufficient oligodendroglial development, probably mediated by mTOR, which may ultimately lead to severe myelin loss. In terms of disease management, an early and targeted treatment could restore normal myelin development and, therefore, alter seizure threshold and improve cognitive outcome.
Amino acid transporter SLC6A14 is a novel and effective drug target for pancreatic cancer
Authors: Coothankandaswamy V , Cao S , Xu Y , Prasad P D , Singh P K , Reynolds C P , Yang S , Ogura J , Ganapathy V , Bhutia Y D
Published: October 2016

Background and Purpose

Pancreatic cancer is a solid tumour that is often fatal. Hence, there is an urgent need to identify new drug targets for this disease. Highly proliferating cancer cells have an increased demand for nutrients and, therefore, need to up‐regulate selective amino acid transporters. Here, we investigated which amino acid transporters are up‐regulated in pancreatic cancer and whether any of these transporters has potential as a drug target for this fatal disease.

Experimental Approach

The expression of amino acid transporters in pancreatic cancer was analysed using publicly available microarray datasets, and the findings with the transporter SLC6A14 were validated by mRNA and protein analysis. The potential of SLC6A14 as a drug target was evaluated using a pharmacological blocker in vitro and in vivo.

Key Results

SLC6A14 was up‐regulated several fold in patient‐derived xenografts, primary tumour tissues and pancreatic cancer cells lines compared to normal pancreatic tissue or normal pancreatic epithelial cells. The magnitude of the up‐regulation of SLC6A14 was the highest among the amino acid transporters examined. A pharmacological blocker of SLC6A14, α‐methyltryptophan, induced amino acid starvation in pancreatic cancer cells and reduced the growth and proliferation of these cells, both in vitro and in vivo.

Conclusion and Implications

The salient features of this study are that SLC6A14 is markedly up‐regulated in pancreatic cancer and that pharmacological blockade of this transporter interferes with amino acid nutrition and reduces growth and proliferation of pancreatic cancer cells. These findings identify SLC6A14 as a novel druggable target for pancreatic cancer.
Anionic chlorido(triphenyl)tin(IV) bearing N‐phthaloylglycinato or 1,2,4‐benzenetricarboxylato 1,2‐anhydride ligands: potential cytotoxic and apoptosis‐inducing agents against several types of cancer
Authors: Hübner Denise , Kaluđerović Milena R. , Gómez‐Ruiz Santiago , Kaluđerović Goran N.
Published: October 2016

Two ionic triphenyltin(IV) chloride carboxylate compounds of the formula [NHEt3][Ph3SnCl(L)] [LH = N‐phthaloylglycine (P‐GlyH), 1; 1,2,4‐benzenetricarboxylic 1,2‐anhydride (BTCH), 2] were tested for the in vitro activity against 518A2 (melanoma), FaDu (head and neck carcinoma), HT‐29 (colon cancer), MCF‐7 (breast carcinoma), and SW1736 (thyroid cancer) cell lines. The ammonium salts of the carboxylic acids are found to be not active, while anionic [Ph3SnCl(L)]− exhibited high cytotoxicity in nM range, both higher activity and selectivity than cisplatin. Compounds 1 and 2 are inducing apoptosis, which was proved with the morphological and biochemical features such as membrane blebbing, translocation of phosphatidylserine, and DNA fragmentation. Thus, accumulation of cells in sub‐G1 phase is observed. Both anionic organotin(IV) compounds showed potent cytotoxic and apoptotic properties against five cancer cell lines of various histogenetic origin.
BRF1 mutations in a family with growth failure, markedly delayed bone age, and central nervous system anomalies
Authors: Jee Y.H. , Sowada N. , Markello T.C. , Rezvani I. , Borck G. , Baron J.
Published: October 2016

Linear growth failure can be caused by many different genetic abnormalities. In many cases, the genetic defect affects not only the growth plate, causing short stature but also other organs/tissues causing additional clinical abnormalities. A 10‐year old boy was evaluated for impaired postnatal linear growth (height 113.3 cm, −4.6 SDS), a bone age that was delayed by 5 years, dysmorphic facies, cognitive impairment, and central nervous system anomalies. His younger brother, presented only with growth failure at 10 months of age. Exome sequencing identified compound heterozygous variants in the gene encoding RNA polymerase III transcription initiation factor 90 kDa subunit (BRF1) in both affected siblings: a missense mutation (c.875 C > G:p.P292R) and a frameshift mutation (c.551delG:p.C184Sfs). The frameshift mutation is expected to lead to nonsense‐mediated mRNA decay (NMD) and/or to protein truncation. Expression of BRF1 with the P292R missense mutation failed to rescue yeast lacking BRF1. The findings confirm a previous report showing that biallelic mutations in BRF1 cause cerebellar–facial–dental syndrome. Our findings also help define the growth phenotype, indicating that the linear growth failure can become clinically evident before the neurological abnormalities and that a severely delayed bone age may serve as a diagnostic clue.
Numerical magnitude processing impairments in genetic syndromes: a cross‐syndrome comparison of Turner and 22q11.2 deletion syndromes
Authors: Brankaer Carmen , Ghesquière Pol , De Wel Anke , Swillen Ann , De Smedt Bert
Published: October 2016

Cross‐syndrome comparisons offer an important window onto understanding heterogeneity in mathematical learning disabilities or dyscalculia. The present study therefore investigated symbolic numerical magnitude processing in two genetic syndromes that are both characterized by mathematical learning disabilities: Turner syndrome and 22q11.2 deletion syndrome (22q11DS). We further verified whether the phenotypic outcomes of these syndromes emerged from the same or different cognitive processes and therefore examined whether numerical impairments were related to working memory deficits, often observed in these syndromes. Participants were 24 girls with Turner syndrome, 25 children with 22q11DS and 48 well‐matched typically developing control children. All children completed a symbolic numerical magnitude comparison task and four additional working memory tasks. Both groups of children with genetic syndromes showed similar impairments in symbolic numerical magnitude processing compared to typically developing controls. Importantly, in Turner syndrome, group differences in symbolic numerical magnitude processing disappeared when their difficulties in visual‐spatial working memory were taken into account. In contrast, the difficulties in 22q11DS were not explained by poor visual‐spatial working memory. These data suggest that different factors underlie the symbolic numerical magnitude processing impairments in both patient groups with mathematical learning disabilities and highlight the value of cross‐syndrome comparisons for understanding different pathways to mathematical learning disabilities or dyscalculia.