bluuebunny/crossref_metadata_2025 huggingface dataset:
Laparoscopic hepatectomy is theoretically better than open hepatectomy: preparing for the 2nd International Consensus Conference on Laparoscopic Liver Resection
Authors: Wakabayashi Go , Cherqui Daniel , Geller David A. , Han Ho‐Seong , Kaneko Hironori , Buell Joseph F.
Published: August 2014

Six years have passed since the first International Consensus Conference on Laparoscopic Liver Resection was held. This comparatively new surgical technique has evolved since then and is rapidly being adopted worldwide. We compared the theoretical differences between open and laparoscopic liver resection, using right hepatectomy as an example. We also searched the Cochrane Library using the keyword “laparoscopic liver resection.” The papers retrieved through the search were reviewed, categorized, and applied to the clinical questions that will be discussed at the 2nd Consensus Conference. The laparoscopic hepatectomy procedure is more difficult to master than the open hepatectomy procedure because of the movement restrictions imposed upon us when we operate from outside the body cavity. However, good visibility of the operative field around the liver, which is located beneath the costal arch, and the magnifying provide for neat transection of the hepatic parenchyma. Another theoretical advantage is that pneumoperitoneum pressure reduces hemorrhage from the hepatic vein. The literature search turned up 67 papers, 23 of which we excluded, leaving only 44. Two randomized controlled trials (RCTs) are underway, but their results are yet to be published. Most of the studies (n = 15) concerned short‐term results, with some addressing long‐term results (n = 7), cost (n = 6), energy devices (n = 4), and so on. Laparoscopic hepatectomy is theoretically superior to open hepatectomy in terms of good visibility of the operative field due to the magnifying effect and reduced hemorrhage from the hepatic vein due to pneumoperitoneum pressure. However, there is as yet no evidence from previous studies to back this up in terms of short‐term and long‐term results. The 2nd International Consensus Conference on Laparoscopic Liver Resection will arrive at a consensus on the basis of the best available evidence, with video presentations focusing on surgical techniques and the publication of guidelines for the standardization of procedures based on the experience of experts.
Variations in 30‐day hospital readmission rates across primary care clinics within a tertiary referral center
Authors: Tang Ning , Maselli Judith H. , Gonzales Ralph
Published: August 2014

BACKGROUND

Reducing hospital readmissions is a national healthcare priority. Little is known about how readmission rates vary across unique primary care practices.

OBJECTIVE

To calculate all‐cause 30‐day hospital readmission rates at the level of individual primary care practices and identify factors associated with variations in these rates.

DESIGN

Retrospective analysis

SETTING

Seven primary care clinics affiliated with the University of California, San Francisco (UCSF).

PATIENTS

Adults ≥18 years old with a primary care provider (PCP) at UCSF

MEASUREMENTS

All‐cause 30‐day readmission rates were calculated for primary care clinics for discharges between July 1, 2009 and June 30, 2012. We built a model to identify demographic, clinical, and hospital factors associated with variation in rates.

RESULTS

There were 12,564 discharges for patients belonging to the 7 clinics, with 8685 index discharges and 1032 readmissions. Readmission rates varied across practices, from 14.9% in Human Immunodeficiency Virus primary care and 7.7% in women's health. In multivariable analyses, factors associated with variation in readmission rates included: male gender (odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.05–1.40), Medicare insurance (OR: 1.31, 95% CI: 1.05, 1.64; Ref = private), Medicare‐Medicaid dual eligible (OR: 1.26, 95% CI: 1.01–1.56), multiple comorbidities, and admitting services. Patients with a departed PCP awaiting transfer assignment to a new PCP had an OR of 1.59 (95% CI: 1.16–2.17) compared with having a current faculty PCP.

CONCLUSIONS

Primary care practices are important partners in improving care transitions and reducing hospital readmissions, and this study introduces a new way to view readmission rates. PCP turnover may be an important risk factor for hospital readmissions. Journal of Hospital Medicine 2014;9:688–694. © 2014 Society of Hospital Medicine
Tibial articular cartilage and meniscus geometries combine to influence female risk of anterior cruciate ligament injury
Authors: Sturnick Daniel R. , Van Gorder Robert , Vacek Pamela M. , DeSarno Michael J. , Gardner‐Morse Mack G. , Tourville Timothy W. , Slauterbeck James R. , Johnson Robert J. , Shultz Sandra J. , Beynnon Bruce D.
Published: August 2014

Tibial plateau subchondral bone geometry has been associated with the risk of sustaining a non‐contact ACL injury; however, little is known regarding the influence of the meniscus and articular cartilage interface geometry on risk. We hypothesized that geometries of the tibial plateau articular cartilage surface and meniscus were individually associated with the risk of non‐contact ACL injury. In addition, we hypothesized that the associations were independent of the underlying subchondral bone geometry. MRI scans were acquired on 88 subjects that suffered non‐contact ACL injuries (27 males, 61 females) and 88 matched control subjects that were selected from the injured subject's teammates and were thus matched on sex, sport, level of play, and exposure to risk of injury. Multivariate analysis of the female data revealed that increased posterior‐inferior directed slope of the middle articular cartilage region and decreased height of the posterior horn of the meniscus in the lateral compartment were associated with increased risk of sustaining a first time, non‐contact ACL injury, independent of each other and of the slope of the tibial plateau subchondral bone. No measures were independently related to risk of non‐contact ACL injury among males. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1487–1494, 2014.
Monolithic silica columns functionalized with substituted polyproline‐derived chiral selectors as chiral stationary phases for high‐performance liquid chromatography
Authors: Sancho Raquel , Novell Arnau , Svec Frantisek , Minguillón Cristina
Published: August 2014

In this study, two polyproline‐derived chiral selectors are bonded to monolithic silica gel columns. In spite of high chiral selector coverage, the derivatization was found to have only a slight effect on the hydrodynamics of the mobile phase through the column. The enantioseparation ability of the resulting chiral monolithic columns was evaluated with a series of structurally diverse racemic test compounds. When compared to analogous bead‐based chiral stationary phases, higher enantioseparation and broader application domain were observed for monolithic columns. Moreover, the increase in flow rate produces a minor reduction of resolution, which permits to shorten analysis time. Additionally, increased loadability defines chiral polyproline derived monoliths as adequate for preparative chromatography.
Materials characterization and mechanical properties of graded tool steels processed by a new co‐spray forming technique
Authors: Cui C. , Schulz A. , Uhlenwinkel V.
Published: August 2014

In order to meet the requirements of micro cold forming tools, a new co‐spray forming process has been applied to produce graded materials from two different tool steels in this study. The two steel melts were atomized and co‐sprayed simultaneously onto a flat substrate, resulting in a flat graded deposit when the two sprays were overlapped. To eliminate porosity and break up carbide network, the graded deposits were further hot rolled. The resultant graded tool steels were investigated with respect to porosity, element distribution, microstructure, hardness, strength, and toughness. The degree of overlapping of the two sprays determined the concentration gradient of the chemical elements in the deposits. The overlapping of the spray cones also contributed to low porosity in the gradient zone of the deposits. The porosity in the graded deposits could be essentially eliminated by means of hot rolling. The carbides and grain structures of the hot rolled tool steels were fine and homogeneous. By means of combining different tool steels in a single deposit, different microstructures and properties were combined.
Preparation of Nanocomposites of Polypropylene with Carbon Nanotubes via Masterbatches Produced by In Situ Polymerization and by Melt Extrusion
Authors: Araujo Rafael S. , Oliveira Renato J. B. , de Fátima V. Marques Maria
Published: August 2014

In the present study, a new polypropylene (PP)/multi‐walled carbon nanotube (MWCNT) masterbatch is synthesized by in situ polymerization and compared with a masterbatch obtained by melt mixing. Both masterbatches are used for the realization of PP/MWCNT nanocomposites by mixing with a commercial PP in a laboratory extruder. It is shown that the use of masterbatch synthesized in situ allows providing additional enhanced thermal stability and mechanical properties. Samples are characterized according to their thermo dynamic‐mechanical properties, thermal stability, and degree of crystallinity, as well as by scanning electron microscopy. DMA analysis shows that there is a sharp increase in both storage and loss moduli of materials even with very low CNT content, in comparison with the neat PP. By means of thermogravimetric analysis, it is found that the thermal stability of nanocomposites is also increased. Furthermore, the degree of crystallinity of the materials containing CNTs is increased to higher value than that of neat PP, suggesting that the carbon nanotubes act as nucleating agent. A sharper increase ofXcis observed in the composites with low CNT content prepared in the method using melt‐masterbatch, suggesting that there are more agglomerations of CNTs in this material.
Modeling of RAFT Polymerization using Probability Generating Functions. Detailed Prediction of Full Molecular Weight Distributions and Sensitivity Analysis
Authors: Fortunatti Cecilia , Sarmoria Claudia , Brandolin Adriana , Asteasuain Mariano
Published: August 2014

A mathematical model of RAFT polymerization processes is presented capable of predicting the full molecular weight distribution (MWD) through the use of probability generating functions (pgf). The bivariate distribution of the intermediate RAFT species is calculated. The model is able to work with the three kinetic mechanisms currently under discussion for explaining the observed behavior of this type of polymerization. For comparison purposes, the population balances are also solved by direct integration of the resulting equations. The results show that the pgf technique allows obtaining accurate solutions with very small computational times for systems of any average molecular weight. Spurious oscillations observed in the high molecular weight tail of the MWD can be easily disregarded. A sensitivity analysis over several of the kinetic constants is also performed, showing the effects of changing their values over several orders of magnitude. This analysis aims to showcase the enormous potential of the pgf technique for modeling and optimization of complex polymerization kinetics.
A pilot validation of multi‐echo based echo‐planar correlated spectroscopic imaging in human calf muscles
Authors: Furuyama Jon K. , Nagarajan Rajakumar , Roberts Christian K. , Lee Cathy C. , Hahn Theodore J. , Thomas M. Albert
Published: August 2014

A current limitation of MR spectroscopic imaging of multiple skeletal muscles is prolonged scan duration. A significant reduction in the total scan duration using the echo‐planar correlated spectroscopic imaging (EP‐COSI) sequence was accomplished using two bipolar readout trains with different phase‐encoded echoes for one of two spatial dimensions within a single repetition time (TR). The second bipolar readout was used for spatially encoding the outer k‐space, whereas the first readout was used for the central k‐space only. The performance of this novel sequence, called multi‐echo based echo‐planar correlated spectroscopic imaging (ME‐EPCOSI), was demonstrated by localizing specific key features in calf muscles and bone marrow of 11 healthy volunteers and five subjects with type 2 diabetes (T2D). A 3 T MRI–MRS scanner equipped with a transmit–receive extremity coil was used. Localization of the ME‐EPCOSI sequence was in good agreement with the earlier single‐readout based EP‐COSI sequence and the required scan time was reduced by a factor of two. In agreement with an earlier report using single‐voxel based 2D MRS, significantly increased unsaturated pools of intramyocellular lipid (IMCL) and extramyocellular lipid (EMCL) and decreased IMCL and EMCL unsaturation indices (UIs) were observed in the soleus and tibialis anterior muscle regions of subjects with T2D compared with healthy controls. In addition, significantly decreased choline content was observed in the soleus of T2D subjects compared with healthy controls. Multi‐voxel characterization of IMCL and EMCL ratios and UI in the calf muscle may be useful for the non‐invasive assessment of altered lipid metabolism in the pathophysiology of T2D. Copyright © 2014 John Wiley & Sons, Ltd.
Identification of Phenanthrene Derivatives in Aerides rosea (Orchidaceae) Using the Combined Systems HPLC–ESI–HRMS/MS and HPLC–DAD–MS–SPE–UV–NMR
Authors: Cakova Veronika , Urbain Aurélie , Antheaume Cyril , Rimlinger Nicole , Wehrung Patrick , Bonté Frédéric , Lobstein Annelise
Published: August 2014

Introduction

In our continued efforts to contribute to the general knowledge on the chemical diversity of orchids, we have decided to focus our investigations on the Aeridinae subtribe. Following our previous phytochemical study of Vanda coerulea, which has led to the identification of phenanthrene derivatives, a closely related species, Aerides rosea Lodd. ex Lindl. & Paxton, was chosen for investigation.

Objective

To identify new secondary metabolites, and to avoid isolation of those already known, by means of the combined systems HPLC–DAD(diode‐array detector) with high‐resolution tandem mass spectrometry (HRMS/MS) and HPLC–DAD–MS–SPE(solid‐phase extraction)–UV–NMR.

Methods

A dereplication strategy was developed using a HPLC–DAD–HRMS/MS targeted method and applied to fractions from A. rosea stem extract. Characterisation of unknown minor compounds was then performed using the combined HPLC–DAD–MS–SPE–UV–NMR system.

Results

The dereplication method allowed the characterisation of four compounds (gigantol, imbricatin, methoxycoelonin and coelonin), previously isolated from Vanda coerulea stem extract. The analyses of two fractions permitted the identification of five additional minor constituents including one phenanthropyran, two phenanthrene and two dihydrophenanthrene derivatives. The full set of NMR data of each compound was obtained from microgram quantities.

Conclusion

Nine secondary metabolites were characterised in A. rosea stems, utilising HPLC systems combined with high‐resolution analytical systems. Two of them are newly described phenanthrene derivatives: aerosanthrene (5‐methoxyphenanthrene‐2,3,7‐triol) and aerosin (3‐methoxy‐9,10‐dihydro‐2,5,7‐phenanthrenetriol). Copyright © 2014 John Wiley & Sons, Ltd.
Intranasal NAP (davunetide) decreases tau hyperphosphorylation and moderately improves behavioral deficits in mice overexpressing α‐synuclein
Authors: Magen Iddo , Ostritsky Regina , Richter Franziska , Zhu Chunni , Fleming Sheila M. , Lemesre Vincent , Stewart Alistair J. , Morimoto Bruce H. , Gozes Illana , Chesselet Marie‐Françoise
Published: August 2014

Genome‐wide association studies have identified strong associations between the risk of developing Parkinson's disease (PD) and polymorphisms in the genes encoding α‐synuclein and the microtubule‐associated protein tau. However, the contribution of tau and its phosphorylated form (p‐tau) to α‐synuclein‐induced pathology and neuronal dysfunction remains controversial. We have assessed the effects of NAP (davunetide), an eight‐amino acid peptide that decreases tau hyperphosphorylation, in mice overexpressing wild‐type human α‐synuclein (Thy1‐aSyn mice), a model that recapitulates aspects of PD. We found that the p‐tau/tau level increased in a subcortical tissue block that includes the striatum and brain stem, and in the cerebellum of the Thy1‐aSyn mice compared to nontransgenic controls. Intermittent intranasal NAP administration at 2 μg/mouse per day, 5 days a week, for 24 weeks, starting at 4 weeks of age, significantly decreased the ratio of p‐tau/tau levels in the subcortical region while a higher dose of 15 μg/mouse per day induced a decrease in p‐tau/tau levels in the cerebellum. Both NAP doses reduced hyperactivity, improved habituation to a novel environment, and reduced olfactory deficits in the Thy1‐aSyn mice, but neither dose improved the severe deficits of motor coordination observed on the challenging beam and pole, contrasting with previous data obtained with continuous daily administration of the drug. The data reveal novel effects of NAP on brain p‐tau/tau and behavioral outcomes in this model of synucleinopathy and suggest that sustained exposure to NAP may be necessary for maximal benefits.
Effectiveness of improvised gas absorption techniques for emergency responders at releases of toxic gases
Authors: Kern Hannes , Taferner Matthias , Raupenstrauch Harald
Published: August 2014

During accidental releases of toxic gases emergency responders use different measures to eliminate the threat of a toxic gas cloud. Case studies from incidents in Vienna or in Trieben in Austria showed the need for studies on the effectiveness of such measures. An Trieben in 2009 IBC tank with 1,000 l of nitric acid (53%) was flipped over by a forklift and cracked open in the top area. The content was fully released and lead to serious corrosion effects on storage racks combined with the production of critical amounts of nitrous fumes. A storage and chemical handling area of several hundred square meters was filled by nitrous fumes with concentrations of up to 100 ppm. Emergency responders used an improvised gas absorption system to clear the area of toxic fumes. Outside the sealed area concentrations of nitrous fumes well below the AEGL‐2 (4h) value for nitrous dioxide where measured. In the course of the analyses of the response, the effectiveness of improvised gas absorption techniques was investigated. For the investigations, chlorine and ammonia in combination with a mobile exhauster, (10,000 m3/h) commonly used by emergency responders in Austria were used. Different methods of gas absorption were investigated and tested on their practical relevance. © 2014 American Institute of Chemical Engineers Process Saf Prog 34: 154–156, 2015
Data worth and prediction uncertainty for pesticide transport and fate models in Nebraska and Maryland, United States
Authors: Nolan Bernard T , Malone Robert W , Doherty John E , Barbash Jack E , Ma Liwang , Shaner Dale L
Published: August 2014

BACKGROUND

Complex environmental models are frequently extrapolated to overcome data limitations in space and time, but quantifying data worth to such models is rarely attempted. The authors determined which field observations most informed the parameters of agricultural system models applied to field sites in Nebraska (NE) and Maryland (MD), and identified parameters and observations that most influenced prediction uncertainty.

RESULTS

The standard error of regression of the calibrated models was about the same at both NE (0.59) and MD (0.58), and overall reductions in prediction uncertainties of metolachlor and metolachlor ethane sulfonic acid concentrations were 98.0 and 98.6% respectively. Observation data groups reduced the prediction uncertainty by 55–90% at NE and by 28–96% at MD. Soil hydraulic parameters were well informed by the observed data at both sites, but pesticide and macropore properties had comparatively larger contributions after model calibration.

CONCLUSIONS

Although the observed data were sparse, they substantially reduced prediction uncertainty in unsampled regions of pesticide breakthrough curves. Nitrate evidently functioned as a surrogate for soil hydraulic data in well‐drained loam soils conducive to conservative transport of nitrogen. Pesticide properties and macropore parameters could most benefit from improved characterization further to reduce model misfit and prediction uncertainty. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.
Microwave‐assisted 18O labeling of Fmoc‐protected amino acids
Authors: Modzel Maciej , Płóciennik Halina , Kluczyk Alicja , Stefanowicz Piotr , Szewczuk Zbigniew
Published: August 2014

Recently, there has been an increased interest in isotopical labeling of peptides. Although there are several techniques allowing for a complete labeling of all carboxyl groups in peptides, regioselective labeling would be beneficial in many situations. Such labeling requires the use of 18O‐labeled Fmoc amino acids. We have designed a method for such labeling that is an improvement on a technique proposed earlier. The new procedure is suitable for microscale synthesis and could be used in peptide and proteomics laboratories. Although for the majority of tested amino acids our method gives good labeling efficiency, it is time consuming. Therefore, we have decided to use microwave‐assisted procedure. This approach resulted in reduction of reaction time to 15 min and increased reaction efficiency. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.
Robust Data Fusion of Multimodal Sensory Information for Mobile Robots
Authors: Kubelka Vladimír , Oswald Lorenz , Pomerleau François , Colas Francis , Svoboda Tomáš , Reinstein Michal
Published: August 2014

Urban search and rescue (USAR) missions for mobile robots require reliable state estimation systems resilient to conditions given by the dynamically changing environment. We design and evaluate a data fusion system for localization of a mobile skid‐steer robot intended for USAR missions. We exploit a rich sensor suite including both proprioceptive (inertial measurement unit and tracks odometry) and exteroceptive sensors (omnidirectional camera and rotating laser rangefinder). To cope with the specificities of each sensing modality (such as significantly differing sampling frequencies), we introduce a novel fusion scheme based on an extended Kalman filter for six degree of freedom orientation and position estimation. We demonstrate the performance on field tests of more than 4.4  km driven under standard USAR conditions. Part of our datasets include ground truth positioning, indoor with a Vicon motion capture system and outdoor with a Leica theodolite tracker. The overall median accuracy of localization—achieved by combining all four modalities—was 1.2% and 1.4% of the total distance traveled for indoor and outdoor environments, respectively. To identify the true limits of the proposed data fusion, we propose and employ a novel experimental evaluation procedure based on failure case scenarios. In this way, we address the common issues such as slippage, reduced camera field of view, and limited laser rangefinder range, together with moving obstacles spoiling the metric map. We believe such a characterization of the failure cases is a first step toward identifying the behavior of state estimation under such conditions. We release all our datasets to the robotics community for possible benchmarking.
From model building to validation and back: a plea for robustness
Authors: van Houwelingen Hans C.
Published: August 2014

This paper is the written version of the President's invited lecture speaker at the International Society for Clinical Biostatistics conference in Munich in 2013. The paper takes the stand of clinician and patient who are in need of a reliable prognostic model for the planning of treatment and patient care during the follow‐up after the initial treatment. The paper discusses (i) the need for grouping of data; (ii) the lack of robustness of the Cox model; (iii) the robust approach to repeated measures; and (iv) the robust handling of time‐dependent covariates (biomarkers) in dynamic survival analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Illegitimate Tasks and Sleep Quality: An Ambulatory Study
Authors: Pereira Diana , Semmer Norbert K. , Elfering Achim
Published: August 2014

The current study investigated the short‐term effect of illegitimate tasks on sleep quality, assessed by actigraphy. Seventy‐six employees of different service jobs participated in a 2‐week data collection. Data were analysed by way of multilevel analyses. As predicted, illegitimate tasks were positively related to sleep fragmentation and sleep‐onset latency, but not to sleep efficiency and not to sleep duration. Time pressure, social stressors at work and at home, and the value of the dependent variable from the previous day were controlled. Results confirm the predictive power of illegitimate tasks for a variable that can be considered crucial in the development of long‐term outcomes of daily experiences. Copyright © 2014 John Wiley & Sons, Ltd.
Emotional versus Cognitive Rumination: Are They Differentially Affecting Long‐term Psychological Health? The Impact of Stressors and Personality in Dental Students
Authors: Hamesch Ulla , Cropley Mark , Lang Jessica
Published: August 2014

In the process of recovery from work, rumination is considered as an important mediating variable in the relationship between work demands and psychological health outcomes. Past research differentiated affective rumination from problem‐solving pondering. The aim of the present study was to test a moderated mediation model for these two distinct ruminative states and to show how personality (i.e. neuroticism and conscientiousness) can alter the mediating effect. The present study is based on 119 surveys from dental students with a time lag of 6 months. Participants filled out questionnaires assessing specific study‐relevant performance demands, rumination and personality and a screening measure for psychological health status.

Neuroticism was found to moderate the demand‐affective rumination association, but conscientiousness did not moderate the demand–problem‐solving pondering association. Moderated mediation analysis revealed that affective rumination mediates the impact of demands on psychological health only for individuals low in neuroticism. Findings are discussed regarding potential interventions for dental students to prevent negative psychological health outcomes due to increased work‐related demands in the long term. Copyright © 2014 John Wiley & Sons, Ltd.
An empirical study of the effect of file editing patterns on software quality
Authors: Zhang Feng , Khomh Foutse , Zou Ying , Hassan Ahmed E.
Published: August 2014

Developers might follow different file editing patterns when handling change requests. Existing research has warned the community about the potential negative impacts of some file editing patterns on software quality. However, very few studies have provided quantitative evidence to support these claims. In this paper, we propose four metrics to identify four file editing patterns: concurrent editing pattern, parallel editing pattern, extended editing pattern, and interrupted editing pattern. Our empirical study on three open source projects shows that 90% (i.e. 1935 out of 2140) of files exhibit at least one file editing pattern. More specifically (1) files that are edited concurrently by many developers are 1.8 times more likely to experience future bugs than files that are not concurrently edited; (2) files edited in parallel with too many other files by the same developer are 2.9 times more likely to exhibit future bugs than files individually edited; (3) files edited over an extended period of time are 1.9 times more likely to experience future bugs than other files; and (4) files edited with long interruptions have 2.0 times more future bugs than other files. We also observe that the likelihood of future bugs in files experiencing all the four file editing patterns is 3.9 times higher than in files that are never involved in any of the four patterns. We further investigate factors impacting the occurrence of these file editing patterns along three dimensions: the ownership of files, the type of change requests in which the files were involved, and the initial code quality of the files. Results show that a file with a major owner is 0.6 times less likely to exhibit the concurrent editing pattern than files without major owners. Files with bad code quality (e.g. high McCabe's complexity, high coupling between objects, and lack of cohesion) are more likely to experience the four editing patterns. By ensuring a clear ownership and improving code quality, the negative impact of the four patterns could be reduced. Overall, our findings could be used by software development teams to warn developers about risky file editing patterns. Copyright © 2014 John Wiley & Sons, Ltd.
Group Model‐Building to Support Public Policy: Addressing a Conflicted Situation in a Problem Neighbourhood
Authors: Rouwette Etiënne , Bleijenbergh Inge , Vennix Jac
Published: August 2014

This paper evaluates a group model‐building project concerning safety in a city neighbourhood. Stakeholders such as inhabitants, housing association managers, and police were directly involved in constructing a system dynamics model of their situation and defining actions to improve safety. Evaluation studies of group model‐building typically assume that participants in modelling sessions share their insights, and in turn, the information exchanged changes their opinions. The modelling project addressed in this paper concerns a messy problem in a public multi‐organizational setting, a situation characterized by ambiguity and conflict. We show that modelling in an ambiguous and conflicted situation helps participants to exchange information and change their opinions on the issue, even when not all conflicts are openly discussed. Group model‐building positively impacts the quality of conclusions reached. The paper ends with a discussion of limitations and areas for future research. Copyright © 2014 John Wiley & Sons, Ltd.
Twist-1, A Novel Regulator of Hematopoietic Stem Cell Self-Renewal and Myeloid Lineage Development
Authors: Dong Cheng-Ya , Liu Xiao-Yan , Wang Nan , Wang Li-Na , Yang Bin-Xia , Ren Qian , Liang Hao-Yue , Ma Xiao-Tong
Published: August 2014

Transcription factor Twist-1 plays essential roles in specification and differentiation of mesoderm-derived tissues. Growing evidences now link Twist-1 to the acquisition of stem-cell-like properties. However, the role of Twist-1 in hematopoietic stem cell (HSC) remains largely uncharacterized. We report that Twist-1 is more highly expressed in murine HSC and its expression declines with differentiation. To investigate Twist-1 gene function, retroviral-mediated overexpression or removal experiments are performed. Competitive repopulation studies demonstrate that enforced expression of Twist-1 in HSC-enriched Lin−c-Kit+Sca-1+ (LKS) cells results in an increase in the size of the G0 population, and in their reconstitution ability after the first and a second transplantation. Conversely, removal of Twist-1 in LKS cells impairs their ability to repopulate. In addition, increased Twist-1 expression causes a shift toward production of myeloid cells. Twist-1 transduction in LKS cells activates myeloid lineage-determining factors PU.1 and GATA-1 and downregulates lymphoid factor GATA-3 in vitro, suggesting that Twist-1-mediated myeloid skewing occurs in hematopoietic stem and progenitor cells (HSPCs). These findings indicate that Twist-1 is not only involved in the maintenance of HSC dormancy and self-renewal capacity but also implicated in the myeloid lineage fate choice of HSPCs. Exploration of the underlying mechanisms reveals that Runx1/c-Mpl/Tie2 regulatory pathway could possibly account for the observed effects caused by Twist-1 overexpression. Our study provides the first evidence supporting a role for Twist-1 in hematopoiesis. Stem Cells  2014;32:3173–3182
Dose‐dependent, saturable occupancy of the metabotropic glutamate subtype 5 receptor by fenobam as measured with [11C]ABP688 PET imaging
Authors: Mathews William B. , Kuwabara Hiroto , Stansfield Kirstie , Valentine Heather , Alexander Mohab , Kumar Anil , Hilton John , Dannals Robert F. , Wong Dean F. , Gasparini Fabrizio
Published: August 2014

Fenobam is a negative allosteric modulator of the metabotropic glutamate receptor subtype 5 (mGluR5) with inverse agonist activity and is expected to contribute to the treatment of neuropsychiatric disorders involving dysfunction of mGluR5 including Fragile X syndrome. This study examined whether [11C]ABP688, an antagonist PET radioligand, competes with fenobam for the same binding site in the nonhuman primate brain and would allow examination of occupancy‐plasma concentration relationships in the evaluation of the drug for target disorders in the human brain. Four paired PET studies with [11C]ABP688 were performed in baboons at a baseline condition and after intravenous treatment with fenobam at different dose levels (0.3–1.33 mg/kg). Total distribution volume (VT) and binding potential (BPND) using the cerebellum as a reference region were obtained by the plasma reference graphical method. Then it was examined whether occupancy follows a dose‐dependent, saturating pattern that was predicted by a modified first‐order Hill equation in individual regions. Baseline regional VT and BPND values agreed with previously published data. Occupancy showed dose‐dependent and saturating patterns in individual regions, reaching >90% occupancy at 1.33 mg/kg dose of fenobam in the majority of regions. To our knowledge, this is the first use of PET to characterize the mGluR5 therapeutic drug fenobam. This study demonstrates a proof of principle for determining the in vivo occupancy of fenobam in primates. The results indicate that [11C]ABP688 and PET may be useful for examination of occupancy of mGluR5 by fenobam, which should prove to be useful for designing future studies and treatment of human disease states. Synapse 68:565–573, 2014. © 2014 Wiley Periodicals, Inc.
Mobile Telephony and Economic Growth in Africa
Authors: Cleeve Emmanuel , Yiheyis Zelealem
Published: August 2014

This article analyzes the impact of mobile telephony on economic growth in Africa. It uses panel data on 36 African countries over the period 1995 to 2010, and estimates an econometric model made up of two equations–one expressing output as a function of mobile telephony, and the other, a demand function, reflecting the possibility of a reverse causation from the former to the latter. Given the importance of telecommunication in the development process and the dire state of fixed‐line telephones in Africa, the explosive growth in mobile telephony on the continent could potentially contribute to addressing some of the important challenges it faces today, including the lack of robust economic growth and of poverty alleviation. Employing panel data estimation procedures, this study finds evidence that supports the view that increased mobile penetration contributes to the growth rate of real gross domestic product (GDP). However, the increase in mobile telephone use was not found to have been significantly influenced by GDP growth. © 2014 Wiley Periodicals, Inc.
Developmental toxicity, EROD, and CYP1A mRNA expression in zebrafish embryos exposed to dioxin‐like PCB126
Authors: Liu Han , Nie Fang‐Hong , Lin Hong‐Ying , Ma Yi , Ju Xiang‐Hong , Chen Jin‐Jun , Gooneratne Ravi
Published: August 2014

Dioxin‐like PCB126 is a persistent organic pollutant that causes a range of syndromes including developmental toxicity. Dioxins have a high affinity for aryl hydrocarbon receptor (AhR) and induce cytochrome P4501A (CYP1A). However, the role of CYP1A activity in developmental toxicity is less clear. To better understand dioxin induced developmental toxicity, we exposed zebrafish (Danio rerio) embryos to PCB126 at concentrations of 0, 16, 32, 64, and 128 μg L−1 from 3‐h post‐fertilization (hpf) to 168 hpf. The embryonic survival rate decreased at 144 and 168 hpf. The fry at 96 hpf displayed gross developmental malformations, including pericardial and yolk sac edema, spinal curvature, abnormal lower jaw growth, and non‐inflated swim bladder. The pericardial and yolk sac edema rate significantly increased and the heart rate declined from 96 hpf compared with the controls. PCB126 did not alter the hatching rate. To elucidate the mechanism of PCB126‐induced developmental toxicity, we conducted ethoxyresorufin‐O‐deethylase (EROD) in vivo assay to determine CYP1A enzyme activity, and real‐time PCR to study the induction of CYP1A mRNA gene expression in embryo/larval zebrafish at 24, 72, 96, and 132 hpf. In vivo EROD activity was induced by PCB126 at 16 μg L−1 concentration as early as 72 hpf but significant increases were observed only in zebrafish exposed to 64 and 128 μg L−1 doses (p < 0.005) at 72, 96, and 132 hpf. Induction of CYP1A mRNA expression was significantly upregulated in zebrafish exposed to 32 and 64 μg L−1 at 24, 72, 96, and 132 hpf. Overall, the severe pericardial and yolk sac edema and reduced heart rate suggest that heart defects are a sensitive endpoint, and the general trend of dose‐dependent increase in EROD activity and induction of CYP1A mRNA gene expression provide evidence that the developmental toxicity of PCB126 to zebrafish embryos is mediated by activation of AhR. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 201–210, 2016.
Different effects of process conditions on PA6/nanoclay composites at nanoclay contents above and below percolation threshold: Rheological, thermo‐dynamical, and thermal properties
Authors: Moghri Mehdi , Garmabi Hamid , Kiany Parvin , Seyed Shahabadi Seyed Ismail
Published: August 2014

The effects of several factors (i.e., nanoclay content (NC), melt temperature, screw speed, and feeding rate), on morphology, rheology, thermodynamics, and thermal stability of PA6/NC samples produced in a co‐rotating twin‐screw extruder were studied. We discuss how changes in the level of these factors can vary diffusion or imposed shear, how these variations in diffusion and/or shear can affect NC dispersion, and how the changes in the state of NC dispersion can influence several properties of the samples. Samples with low NC content, below percolation threshold, showed exfoliated/intercalated structure with negligible sensitivity to changes in the level of the factors; whereas, samples with high NC content, above percolation threshold, showed intercalated with sporadic flocculated structures and noticeable sensitivity to the changes in the level of the factors. Moreover, NC dispersion was found to be mostly diffusion‐controlled: changes that resulted in higher diffusion or residence time (i.e., high melt temperature or low screw speed) also eventuated in better NC dispersion. What is more, percolation threshold was seen to move to lower NC contents as diffusion rate was increased. Moreover, as NC content increased, opposite thermal stability behaviors were observed at above and below the percolation threshold. J. VINYL ADDIT. TECHNOL., 22:259–266, 2016. © 2014 Society of Plastics Engineers
Mechanical and thermal properties of polyvinylchloride/olive residue flour blends treated by gamma irradiation
Authors: Bellili Nadira , Djidjelli Hocine , Boukerrou Amar , Barres Claire , Fenouillot Françoise
Published: August 2014

In this study, gamma irradiation treatments were used to improve the compatibility between poly(vinyl chloride) (PVC) and olive residue flour (ORF). The blends were subjected to gamma irradiation at doses of 10 and 70 kGy. The mechanical, thermal, and morphological behaviors of those blends have been assessed. The irradiated blends exhibit better thermal properties, higher tensile modulus, elongation, and strength at break than those of unirradiated blends. The contact angle of water on the surface of a blend irradiated at doses of 10 and 70 kGy is smaller than that for their corresponding unirradiated blend. These treatments cause surface oxidation of PVC/ORF films, as revealed by Fourier transform infrared (FTIR) spectroscopy analysis. J. VINYL ADDIT. TECHNOL., 22:273–278, 2016. © 2014 Society of Plastics Engineers
Thermally stable antimicrobial polyvinylchloride/maleimido aromatic hydrazide composites
Authors: Mohamed Nadia A. , Abd El‐Ghany Nahed A. , Fahmy Mona M. , Ahmed Marwa H.
Published: August 2014

Antimicrobial novel substituted maleimido aromatic hydrazides were synthesized from N‐[4‐(chlorocarbonyl) phenyl] maleimide with salicylhydrazide, p‐aminobenzohydrazide, or p‐aminosalicylhydrazide. They were characterized by Fourier transform infrared (FTIR), hydrogen‐1 nuclear magnetic resonance (1H‐NMR), mass spectra, elemental analyses, and antimicrobial activities. These derivatives were investigated as thermal stabilizers for rigid poly(vinyl chloride) (PVC) at 180°C in air by measuring the rate of dehydrochlorination, the extent of discoloration, and the changes that occurred in the molecular masses of the degraded PVC samples. The previously reported stabilizing efficiency data of a nonsubstituted derivative, which was synthesized from N‐[4‐(chlorocarbonyl) phenyl] maleimide with benzohydrazide, is also given for comparison. The results reveal the greater stabilizing efficiency of the investigated derivatives as shown by their longer thermal stability (Ts) periods and lower dehydrochlorination rates in relation to dibasic lead carbonate, cadmium‐barium‐zinc stearate, and n‐octyltin mercaptide industrial stabilizers. The stabilizing efficiency increases with the introduction of electron donating substituent groups in the aromatic ring of the stabilizer molecules. Moreover, the investigated stabilizers impart better color stability for the degraded samples as compared with the reference stabilizers. A synergistic effect is achieved when the materials under investigation were mixed in various weight ratios with any of the reference stabilizers, reaching its maximum at equivalent weight ratio of the investigated stabilizer to the reference one. J. VINYL ADDIT. TECHNOL., 22:247–258, 2016. © 2014 Society of Plastics Engineers
On the inference and prediction of DDoS campaigns
Authors: Fachkha Claude , Bou‐Harb Elias , Debbabi Mourad
Published: August 2014

This work proposes a distributed denial‐of‐service (DDoS) inference and forecasting model that aims at providing insights to organizations, security operators, and emergency response teams during and after a DDoS attack. Specifically, our work strives to predict, within minutes, the attacks' features, namely intensity/rate (packets/second) and size (estimated number of used compromised machines/bots). The goal is to understand the future short‐term trend of the ongoing DDoS attack in terms of those features and thus provide the capability to recognize the current as well as future similar situations and hence appropriately respond to the threat. Further, our work aims at investigating DDoS campaigns by proposing a clustering approach to infer various victims targeted by the same campaign and predicting related features. Our analysis employs real darknet data to explore the feasibility of applying the inference and forecasting models on DDoS attacks and evaluate the accuracy of the predictions. To achieve our goal, our proposed approach leverages a number of time series and fluctuation analysis techniques, statistical methods, and forecasting approaches. The extracted inferences from various DDoS case studies exhibit a promising accuracy reaching at some points less than 1% error rate. Further, our approach could lead to a better understanding of the scale, speed, and size of DDoS attacks and generates inferences that could be adopted for immediate response and mitigation. Moreover, the accumulated insights could be used for the purpose of long‐term large‐scale DDoS analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Above 5 cm, Size Does Not Matter Anymore in Patients with Hepatocellular Carcinoma
Authors: Lim Chetana , Mise Yoshihiro , Sakamoto Yoshihiro , Yamamoto Satoshi , Shindoh Junichi , Ishizawa Takeaki , Aoki Taku , Hasegawa Kiyoshi , Sugawara Yasuhiko , Makuuchi Masatoshi , Kokudo Norihiro
Published: August 2014

Background

Solitary hepatocellular carcinoma (HCC) is a good candidate for surgical resection. However, the significance of the size of the tumor in solitary HCC remains unclear.

Objective

The aim of this study was to evaluate the impact of tumor size on overall and recurrence‐free survival of patients with solitary HCC.

Materials

We retrospectively reviewed 616 patients with histologically confirmed solitary HCC who underwent curative surgical resection between 1994 and 2010. The characteristics and prognosis of patients with HCC were analyzed stratified by tumor size.

Results

A total of 403 patients (65 %) had tumors <5 cm, 172 (28 %) had tumors between 5 and 10 cm, and 41 (7 %) had tumors >10 cm. The incidence of microvascular invasion, satellite nodules, and advanced tumor grade significantly increased with tumor size. The 5‐year overall and recurrence‐free survival rates of HCC <5 cm were 69.6 % and 32 %, respectively, which were significantly better than those of HCC between 5 and 10 cm (58 % and 26 %, respectively) and HCC >10 cm (53 % and 24 %, respectively). On multivariate analysis, cirrhosis (p = 0.0307), Child–Pugh B (p = 0.0159), indocyanine green retention rate at 15 min >10 % (p = 0.0071), microvascular invasion (p < 0.0001), and satellite nodules (p = 0.0009) were independent predictors of poor survival, whereas tumor size >5 cm was not.

Conclusion

Although recurrence rates are high, surgical resection for solitary HCC offers good overall survival. Tumor size was not a prognostic factor. Solitary large HCC >10 cm would be a good candidate for hepatectomy as well as solitary HCC between 5 and 10 cm.
Time‐Based Trauma‐Related Mortality Patterns in a Newly Created Trauma System
Authors: Abdelrahman Husham , El‐Menyar Ayman , Al‐Thani Hassan , Consunji Rafael , Zarour Ahmad , Peralta Ruben , Parchani Ashok , Latifi Rifat
Published: August 2014

Background

Data on time‐based trauma mortality (TTM) patterns in developing countries are lacking.

Objective

Our objective was to analyze the TTM in a newly established trauma center.

Methods

A retrospective analysis of all trauma‐related mortality between 2010 and 2012 was conducted in Qatar. Based on the time of injury, deceased cases were categorized into immediate (pre‐hospital), early (first 24 h), and late (>24 h) groups. TTM was analyzed and compared.

Results

A total of 4,966 trauma patients were admitted to the trauma center over 3 years; of them, 333 trauma‐related deaths (6.8 %) were documented and reviewed. The death pattern peaked immediately post‐trauma (n = 142), followed by 96 deaths within the first 24 h, 19 deaths within the time period >24 to 48 h, 50 deaths within the 3rd and 7th day (second peak), and 26 deaths after the 1st week. The majority of the deceased were males, with a mean age of 36 ± 17 years. Motor vehicle crashes (43.5 %) were the commonest mechanism of injury. At presentation, median injury severity score (ISS) was 32 (range 9–75). Bleeding, abdominal, and pelvic injuries were higher in the early group, whereas head injuries were observed more in the late mortality group. Co‐morbidities and in‐hospital complications were predominantly encountered in the late group. Head injury (odds ratio [OR] 3.760; 95 % confidence interval [CI] 1.311–10.797) was an independent predictor for late death, whereas the need for blood transfusion was a predictor for early death (OR 3.233; 95 % CI 1.125–9.345).

Conclusion

The distribution of mortality shows a bimodal pattern. The high rate of death at the scene highlights the importance of pre‐hospital care and the need for injury prevention programs.