bluuebunny/crossref_metadata_2025 huggingface dataset:
Synchronous tRNA movements during translocation on the ribosome are orchestrated by elongation factor G and GTP hydrolysis
Authors: Holtkamp Wolf , Wintermeyer Wolfgang , Rodnina Marina V.
Published: August 2014

The translocation of tRNAs through the ribosome proceeds through numerous small steps in which tRNAs gradually shift their positions on the small and large ribosomal subunits. The most urgent questions are: (i) whether these intermediates are important; (ii) how the ribosomal translocase, the GTPase elongation factor G (EF‐G), promotes directed movement; and (iii) how the energy of GTP hydrolysis is coupled to movement. In the light of recent advances in biophysical and structural studies, we argue that intermediate states of translocation are snapshots of dynamic fluctuations that guide the movement. In contrast to current models of stepwise translocation, kinetic evidence shows that the tRNAs move synchronously on the two ribosomal subunits in a rapid reaction orchestrated by EF‐G and GTP hydrolysis. EF‐G combines the energy regimes of a GTPase and a motor protein and facilitates tRNA movement by a combination of directed Brownian ratchet and power stroke mechanisms.
THE INFLUENCE OF ANTECEDENTS AND CONSEQUENCES ON THE OCCURRENCE OF BIZARRE SPEECH IN INDIVIDUALS WITH DEMENTIA
Authors: Trahan Maranda A. , Donaldson Jeanne M. , McNabney Matthew K. , Kahng SungWoo
Published: August 2014

We conducted a series of assessments to determine the differential effects of common antecedents and consequences that can influence the occurrence of bizarre speech in three women with moderate to severe dementia. First, a traditional functional analysis was conducted to assess the function of bizarre speech. After results revealed differentially higher levels of bizarre speech during control sessions, an antecedent analysis was conducted. During this second assessment, all consequences were held constant, and only the antecedents (i.e., open‐ended questions, yes/no questions, and comments) were altered. Bizarre speech was differentially higher when open‐ended questions were presented, replicating previous studies. The final assessment conducted was a modified functional analysis to further assess the effects of consequences on bizarre speech. More typical consequences were assessed, including two tests for a positive function (attention in the form of correction and attention in the form of following along) and two tests for a negative function (a break from one question and a break from all questions). Results consistently revealed that antecedents produced greater differentiation in responding than social consequences. These findings provide evidence that behavioral assessments may need to be modified to better capture the relevant environmental variables that influence problem behavior in individuals with dementia. Copyright © 2014 John Wiley & Sons, Ltd.
BRIEF (TEST‐CONTROL) FUNCTIONAL ANALYSIS AND TREATMENT EVALUATION OF AGGRESSIVE BEHAVIOR EVOKED BY DIVIDED ATTENTION
Authors: Strohmeier Craig , Pace Gary M. , Luiselli James K.
Published: August 2014

We measured the effects of divided attention on the aggressive behavior of a 20‐year‐old man within a test‐control functional analysis (FA; Iwata, B. A., Duncan, B. A., Zarcone, J. R., Lerman, D. C., & Shore, B. A. (1994). A sequential, test‐control methodology for conducting functional analyses of self‐injurious behavior. Behavior Modification, 18, 289–306). The FA confirmed that divided attention was associated with high‐frequency aggression and aggression‐contingent attention from a familiar and preferred staff person. A subsequent treatment evaluation confirmed that aggression decreased when the man was able to request attention from the staff person under the divided attention condition. We discuss the clinical utility of a divided attention and test‐control methodology when conducting a FA of serious problem behavior within applied settings Copyright © 2014 John Wiley & Sons, Ltd.
Rapid one‐step purification of single‐cells encapsulated in alginate microcapsules from oil to aqueous phase using a hydrophobic filter paper: Implications for single‐cell experiments
Authors: Lee Do‐Hyun , Jang Miran , Park Je‐Kyun
Published: August 2014

By virtue of the biocompatibility and physical properties of hydrogel, picoliter‐sized hydrogel microcapsules have been considered to be a biometric signature containing several features similar to that of encapsulated single cells, including phenotype, viability, and intracellular content. To maximize the experimental potential of encapsulating cells in hydrogel microcapsules, a method that enables efficient hydrogel microcapsule purification from oil is necessary. Current methods based on centrifugation for the conventional stepwise rinsing of oil, are slow and laborious and decrease the monodispersity and yield of the recovered hydrogel microcapsules. To remedy these shortcomings we have developed a simple one‐step method to purify alginate microcapsules, containing a single live cell, from oil to aqueous phase. This method employs oil impregnation using a commercially available hydrophobic filter paper without multistep centrifugal purification and complicated microchannel networks. The oil‐suspended alginate microcapsules encapsulating single cells from mammalian cancer cell lines (MCF–7, HepG2, and U937) and microorganisms (Chlorella vulgaris) were successfully exchanged to cell culture media by quick (∼10 min) depletion of the surrounding oil phase without coalescence of neighboring microcapsules. Cell proliferation and high integrity of the microcapsules were also demonstrated by long‐term incubation of microcapsules containing a single live cell. We expect that this method for the simple and rapid purification of encapsulated single‐cell microcapsules will attain widespread adoption, assisting cell biologists and clinicians in the development of single‐cell experiments.
Construction and evaluation of a genetic construct for specific detection and measurement of propionate by whole‐cell bacteria
Authors: Li Yueh‐Fen , Yu Zhongtang
Published: August 2014

Anaerobic digestion is a microbiological technology that converts biomass wastes into biogas, achieving both waste treatment and bioenergy production. Accumulation of volatile fatty acids (VFA) during acidogenesis, particularly propionate, often causes upset or failure of digesters. Early detection and monitoring of propionate concentration in digesters allow for just‐in‐time interventions to prevent irreversible costly process breakdown. In an attempt to develop a rapid method of measuring propionate concentration and bioavailability, we constructed a genetic construct for specific detection of bioavailable propionate. The genetic construct was constructed by transcriptional fusion of the regulatory gene (prpR) and the promoter of the prp operon (PprpB) of Escherichia coli W3110 with the reporter gene cassette luxCDABE. When the genetic construct was carried on a plasmid and transformed into E. coli (referred to as plasmid‐based biosensor), it resulted in stronger emission of luminescence than when it was inserted into the chromosome of E. coli (referred to as chromosome‐based biosensor). The biosensor responded specifically to propionate. The luminescence signal increased linearly with increasing concentration of propionate from 1 to 10 mM. The utility of the biosensor was evaluated using samples collected from anaerobic digesters. Once instrumented in future studies, the whole‐cell bacterial biosensor developed in this study may provide an alternative technology for real‐time detection and measurement of propionate in digesters. Biotechnol. Bioeng. 2015;112: 280–287. © 2014 Wiley Periodicals, Inc.
Lymphaticovenular anastomosis to prevent cellulitis associated with lymphoedema
Authors: Mihara M , Hara H , Furniss D , Narushima M , Iida T , Kikuchi K , Ohtsu H , Gennaro P , Gabriele G , Murai N
Published: August 2014

Background

One of the complications of lymphoedema is recurrent cellulitis. The aim was to determine whether lymphaticovenous anastomosis (LVA) was effective at reducing cellulitis in patients with lymphoedema.

Methods

This was a retrospective review of patients with arm/leg lymphoedema who underwent LVA. The frequency of cellulitis was compared before and after surgery. The diagnostic criteria for cellulitis were a fever of 38·5°C or higher, and warmth/redness in the affected limb(s).

Results

A total of 95 patients were included. The mean number of episodes of cellulitis in the year preceding surgery was 1·46, compared with 0·18 in the year after surgery (P < 0·001).

Conclusion

LVA reduced the rate of cellulitis in these patients with lymphoedema.
Outcome of surgery for pancreatic neuroendocrine neoplasms
Authors: Fischer L , Bergmann F , Schimmack S , Hinz U , Prieß S , Müller-Stich B P , Werner J , Hackert T , Büchler M W
Published: August 2014

Background

The incidence of pancreatic neuroendocrine neoplasms (pNEN) is increasing. This study aimed to evaluate predictors of overall survival and the indication for surgery.

Methods

Data collected between October 2001 and December 2012 were analysed. Histological grading and staging was based on the classifications of the World Health Organization, the International Union Against Cancer and the European Neuroendocrine Tumour Society.

Results

Some 310 patients (150 female, 48·4 per cent) underwent surgical resection. The final survival analysis included 291 patients. Five-year overall survival differed according to tumour grade (G): 91·0 per cent among 156 patients with pancreatic neuroendocrine tumours (pNET) G1, 70·8 per cent in 111 patients with pNET G2, and 20 per cent in 24 patients with pancreatic neuroendocrine carcinomas (pNEC) G3 (P < 0·001). Tumours graded G3 (hazard ratio (HR) 6·96, 95 per cent confidence interval 3·67 to 13·21), the presence of distant metastasis (HR 2·41, 1·32 to 4·42) and lymph node metastasis (HR 2·10, 1·07 to 4·16) were independent predictors of worse survival (P < 0·001, P = 0·004 and P = 0·032 respectively). Eight of 61 asymptomatic patients with pNEN smaller than 2 cm had tumours graded G2 or G3, and six of 51 patients had lymph node metastasis. Among patients with pNEC G3, the presence of distant metastasis had a significant impact on the 5-year overall survival rate: 0 per cent versus 43 per cent in those without distant metastasis (P = 0·036).

Conclusion

Neuroendocrine tumours graded G3, lymph node and distant metastasis are independent predictors of worse overall survival in patients with pNEN.
Implementation of an acute surgical admission ward
Authors: Eijsvoogel C F H , Peters R W , Budding A J , Ubbink D T , Vermeulen H , Schep N W L
Published: August 2014

Background

The aim of the study was to assess the impact of an acute surgical admission ward on admission and discharge processes.

Methods

This prospective cohort study was conducted in a university tertiary referral centre. All acute surgical patients were clustered in the acute surgical unit (ASU) in February and March 2012, and discharged or transferred to specialized departments within 48 h. The primary outcome was length of hospital stay (LOS). Secondary outcomes were impact on emergency department waiting times, discharge home within 48 h, incorrect ward admissions, readmissions and mortality. Outcomes of the study group were compared with those of a historical reference group admitted during the same interval the year before.

Results

Some 249 patients were admitted to the ASU during the study interval. The reference group consisted of 211 patients. The total LOS decreased significantly from a median of 4·0 to 2·0 days (P = 0·004). The percentage of patients who were discharged within 48 h increased from 30·3 to 43·4 per cent (P = 0·004). The rate of incorrect ward admission decreased from 9·5 to 0 per cent. Emergency department waiting time, readmission rate and 30-day mortality did not change.

Conclusion

Introduction of an acute surgical unit-shortened length of hospital stay without comprising readmission and mortality rates.
Coronary artery compression three months after transcatheter pulmonary valve implantation
Authors: Dehghani Payam , Kraushaar Greg , Taylor Dylan A.
Published: August 2014

We report a case of a 29‐year‐old man who developed exercised‐induced myocardial infarction 3 months post Melody valve implantation. We introduce the concept of ruling out dynamic coronary artery compression by simulating transcatheter pulmonary valve implant while increasing cardiac output and thus aortic dimensions in the catheterization laboratory. © 2014 Wiley Periodicals, Inc.
Ruthenium(II)‐Catalyzed CH Bond Activation: An Efficient Route toward Indenamines
Authors: Hung Chen‐Hsun , Gandeepan Parthasarathy , Cheng Chien‐Hong
Published: August 2014

An efficient and atom‐economical method for the synthesis of substituted indenamines from N‐tosylarylimines and alkynes via ruthenium(II)‐catalyzed CH bond activation and annulation is described. The catalytic reaction proceeds well with a broad substrate scope and in good yields. A possible mechanism is proposed that involves imine nitrogen chelation‐assisted ortho‐CH bond activation of the substrate, alkyne insertion, and intramolecular insertion of the CN Ts group into the CRu bond. Isotope‐labeling experiments are performed to understand the underlying mechanism of the reaction.
Application of foam floods for enhancing heavy oil recovery through stability analysis and core flood experiments
Authors: Shokrollahi Amin , Ghazanfari Mohammad Hossein , Badakhshan Amir
Published: August 2014

This work concerns the investigation of foam application to enhance heavy oil recovery through stability analysis tests, core floods, and data assessment. Monitoring transient behaviour of foam heights in a glass column showed that salt/alkaline concentration/type significantly affects the stability of foam. Meanwhile, the ionic nature of the surfactant and gas type also plays a crucial role. Therefore, the foam stability analysis should be helpful for the successful design of foam floods in enhanced oil recovery (EOR) processes. The surfactants that gave the most stable foam were used in core floods, and found that an increase in surfactant alternating gas (SAG) ratio decreases the oil recovery; furthermore, the efficiency of Cetrimonium Bromide (CTAB) is lower than that of Sodium Dodecyl Sulfate (SDS) in a sandstone core. Finally, the Leverage approach was used to assess the obtained data points of stability as well as core flooding tests through the developed least square supported vector machine (LS‐SVM) models. It confirms the validity of experimental data.
The thermal and transport characteristics of nanofluids in a novel three‐dimensional device
Authors: Singh Jogender , Choudhary Neha , Nigam Krishna Deo Prasad
Published: August 2014

The augmentation in heat transfer can be achieved by improving either transport phenomena with geometry perturbation or thermal conductivity of the fluid itself. In the present study, the simultaneous effects of both the geometry and improved thermal conductivity have been tried on heat transfer enhancement by using two different nanofluids (Al2O3‐water and TiO2‐water). An innovative three‐dimensional device called a coiled flow inverter (CFI) is proposed for the process intensification. The CFI is made up of helical coiled tube, which is bent periodically to 90 ° at equidistant length. In addition to a CFI, the performance characteristics of helical coil and straight tube have been investigated. The Reynolds numbers are in the range of 25–4000, while the nanoparticle volume fraction varied from 0.25–4 %. It was noted that the heat transfer in a CFI improved considerably as compared to helical coil and straight tube of same dimension. The Nusselt number in helical coil augments by 2.5 times to that of straight tube. In the CFI, the Nusselt number further enhanced by 23–35 % as compared to helical coil, with 0–4 % increase in the nanoparticle volume fractions. The new correlations are developed to predict the Nusselt number and friction factor for the flow of nanofluids in the CFI. The number of merit in the CFI to that of straight tube are 1.6–1.8 times, with 0–4 % nanoparticle volume fractions. The present study may motivate the design and development of novel compact heat exchangers as well as a new‐generation microfluidic device.
TGA and kinetic modelling of Co, Mn and Cu oxides for chemical looping gasification (CLG)
Authors: Aghabararnejad Milad , Patience Gregory S. , Chaouki Jamal
Published: August 2014

Oxygen carriers for biomass gasification are capable of absorbing oxygen from air and desorbing it in the gasifier. Based on thermodynamic equilibrium, copper, manganese, and cobalt oxides have the highest oxygen release capacities among the different oxygen carriers. These oxygen carriers were deposited on alumina via incipient wetness impregnation. The weight loss of the CuO–Cu2O carrier, as measured in a thermo‐gravimetric analyzer, was 10 % while it was 7 % for the Co3O4–CoO couple and only 3 % for the Mn2O3–Mn3O4 couple. The optimum operating temperature for the CuO oxygen carrier was 100 °C higher compared to the other two at 950 °C. A modified nuclei growth model (MNG) characterizes the weight loss/gain during the reduction‐oxidation cycles. The reduction rate is 3 times higher at 875 °C compared to 825 °C while the oxidation rate decreases more than 10 times. The CuO carrier surface area decreased by 70 %, while it was 30 % and 60 % in the Co3O4 and Mn2O3 carriers, respectively. Cobalt has a lower tendency to sinter at high temperature compared to either copper or manganese and has a higher oxygen transport capacity and oxidation‐reduction rates. Therefore, despite its higher cost and toxicity, it might be considered as a potential oxygen carrier especially for solid fuel gasification.
Implications of a suspicious afirma test result in thyroid fine‐needle aspiration cytology: An institutional experience
Authors: Lastra Ricardo R. , Pramick Michelle R. , Crammer Cody J. , LiVolsi Virginia A. , Baloch Zubair W.
Published: August 2014

BACKGROUND

Fine‐needle aspiration (FNA) biopsy is the most frequently used method for thyroid nodule evaluation. However, up to 30% of cases are considered indeterminate. Surgery is typically recommended for these cases, but up to two‐thirds of indeterminate cases are found to be benign. The Afirma test is used for the preoperative classification of thyroid nodules with indeterminate cytology. This study reviews the authors' institutional experience with Afirma.

METHODS

A cohort of 132 cases of thyroid FNA with Afirma testing was selected from the study files and relevant information was recorded and analyzed. At the study institution, Afirma is mainly performed on atypia of undetermined significance (AUS)/follicular lesion of undetermined significance (FLUS) cases when diagnosed as such on repeat FNA.

RESULTS

The cohort included 98 female (74%) and 34 male (26%) patients. Cytology diagnosis was AUS/FLUS in 68 cases (51.5%), follicular neoplasm (FN) in 39 cases (29.5%), and FN with oncocytic features (FNOF) in 25 cases (19.0%). Of the FNOF cases with suspicious Afirma findings, 2 (15%) were malignant and 11 (85%) were benign. Of the FN cases with suspicious Afirma findings, 9 (53%) were malignant and 8 (47%) were benign. Of the AUS/FLUS cases with suspicious Afirma findings, 10 (63%) were malignant and 6 (37%) were benign.

CONCLUSIONS

The Afirma classifier is a useful tool to aid in the distinction of cytologically indeterminate nodules. Performing Afirma in cases diagnosed as AUS/FLUS on repeat FNA would increase the positive predictive value, thereby minimizing the number of benign cases referred to surgery. Results of the Afirma test could be limited in cases diagnosed as FNOF. Cancer (Cancer Cytopathol) 2014;122:737–744. © 2014 American Cancer Society.
Radial glia phagocytose axonal debris from degenerating overextending axons in the developing olfactory bulb
Authors: Amaya Daniel A. , Wegner Michael , Stolt C. Claus , Chehrehasa Fatemeh , Ekberg Jenny A.K. , St John James A.
Published: August 2014

Axon targeting during the development of the olfactory system is not always accurate, and numerous axons overextend past the target layer into the deeper layers of the olfactory bulb. To date, the fate of the mis‐targeted axons has not been determined. We hypothesized that following overextension, the axons degenerate, and cells within the deeper layers of the olfactory bulb phagocytose the axonal debris. We utilized a line of transgenic mice that expresses ZsGreen fluorescent protein in primary olfactory axons. We found that overextending axons closely followed the filaments of radial glia present in the olfactory bulb during embryonic development. Following overextension into deeper layers of the olfactory bulb, axons degenerated and radial glia responded by phagocytosing the resulting debris. We used in vitro analysis to confirm that the radial glia had phagocytosed debris from olfactory axons. We also investigated whether the fate of overextending axons was altered when the development of the olfactory bulb was perturbed. In mice that lacked Sox10, a transcription factor essential for normal olfactory bulb development, we observed a disruption to the morphology and positioning of radial glia and an accumulation of olfactory axon debris within the bulb. Our results demonstrate that during early development of the olfactory system, radial glia play an important role in removing overextended axons from the deeper layers of the olfactory bulb. J. Comp. Neurol. 523:183–196, 2015. © 2014 Wiley Periodicals, Inc.
Effects of icosapent ethyl (Eicosapentaenoic acid ethyl ester) on pharmacokinetic parameters of rosiglitazone in healthy subjects
Authors: Braeckman Rene A. , Stirtan William G. , Soni Paresh N.
Published: August 2014

Background

Icosapent ethyl is a high‐purity form of eicosapentaenoic acid ethyl ester approved to reduce triglyceride levels in adults with triglycerides ≥500 mg/dL. Candidates for triglyceride‐lowering therapy include patients with diabetes mellitus who may be receiving rosiglitazone. We assessed the effects of icosapent ethyl on the pharmacokinetic parameters of rosiglitazone.

Methods

Subjects received a single 8‐mg oral dose of rosiglitazone alone and with oral icosapent ethyl 4 g/day in this open‐label drug–drug interaction study. Pharmacokinetic end points included area under the concentration versus time curve from time zero to infinity (AUC0–inf) and maximum observed concentration (Cmax) for rosiglitazone with and without icosapent ethyl.

Results

Of 30 subjects enrolled, 28 completed the study. Icosapent ethyl 4 g/day at steady‐state did not significantly change the single‐dose AUC0–infor Cmaxof rosiglitazone 8 mg. Least squares geometric mean ratios (90% confidence interval) for AUC0–infand Cmaxof rosiglitazone given with icosapent ethyl versus rosiglitazone alone were 0.90 (87.00–93.40) and 1.01 (92.02–109.9), respectively. No serious adverse events were reported and no subject discontinued due to an adverse event.

Conclusions

At steady‐state concentrations, icosapent ethyl did not inhibit the pharmacokinetics of rosiglitazone. Co‐administration of icosapent ethyl and rosiglitazone was safe and well tolerated.
Effect of food on the pharmacokinetics of canagliflozin, a sodium glucose co‐transporter 2 inhibitor, and assessment of dose proportionality in healthy participants
Authors: Devineni Damayanthi , Manitpisitkul Prasarn , Murphy Joseph , Stieltjes Hans , Ariyawansa Jay , Di Prospero Nicholas A. , Rothenberg Paul
Published: August 2014

Canagliflozin, an orally active inhibitor of sodium glucose co‐transporter 2, is approved for the treatment of type‐2 diabetes mellitus. The effect of food on the pharmacokinetics of 300 mg canagliflozin, and dose proportionality of 50, 100, and 300 mg canagliflozin, were evaluated, in two studies, in healthy participants. Study 1 used a randomized, 2‐way crossover design: canagliflozin 300 mg/day was administered under fasted (Period‐1) and fed (Period‐2) conditions or vice versa. Study 2 was a 3‐way crossover: participants were randomized to receive three single‐doses of canagliflozin (50, 100, and 300 mg), one in each period. In both studies, treatment periods were separated by washout intervals of 10–14 days, and pharmacokinetics assessed up to 72 hours postdose of each treatment period. No clinically relevant food effects on canagliflozin exposure parameters were observed: 90% confidence intervals (CIs) for the fed/fasted geometric mean ratios of AUC∞ (ratio: 100.51; 90% CI: 89.47–112.93) and Cmax (ratio: 108.09; 90% CI: 103.45–112.95) were entirely within bioequivalence limits (80–125%). Plasma canagliflozin exposures were dose‐proportional as the 90% CI of the slope of the regression line for dose‐normalized AUC∞ and Cmax fell entirely within the prespecified limits of −0.124 to 0.124. No clinically significant safety issues were noted, and canagliflozin was generally well‐tolerated.
An analysis of definition and placement of virtual machines for high performance applications on Clouds
Authors: Mc Evoy Giacomo , Mury Antonio R. , Schulze Bruno
Published: August 2014

The efficient deployment of high performance computing applications on Clouds offers many challenges, in particular, for communication‐intensive applications. One strategy to mitigate performance overheads caused by high‐communication latency is to schedule requested virtual machines (VMs) effectively onto physical resources by optimizing VM placement. In current approaches based on Infrastructure as a Service resource provisioning, the task of selecting VM profiles is either left to the user or resolved with policies independent from usage patterns, with potential for performance degradation caused by virtualization overhead. Also, most VM placement heuristics disregard the topology of virtual clusters, resource usage patterns of each application, and competing workloads. In this paper, we study the case of scientific applications in virtual clusters by analyzing how different VM profiles and placements can affect observed performance of a parallel application that uses distributed memory. We propose a description for the characteristics of a virtual cluster through the placement of virtual cores, analyze different configurations with a software for systematic execution of virtual clusters, and explain the observed performance in terms of virtual cluster features and resource usage patterns of the application. Our analysis shows that other factors besides the number of cores can have significant effect on performance, such as virtual core mappings and VM spreading. We discuss how our methodology can be extended toward developing performance models, which are aware of resource contention and virtual cluster topology. Copyright © 2014 John Wiley & Sons, Ltd.
A Dynamical method to estimate gene regulatory networks using time‐series data
Authors: Tu Chengyi
Published: August 2014

We propose an improved discrete dynamical system model to reconstruct the gene regulatory network (GRN), then estimate the variable topology using discrete‐time autosynchronization and predict the expression rate under the same condition. Although our method adopts a small number of sample time points to estimate the GRN, it could discern not only the role of the activator or repressor for each specific regulator, but also the regulatory ability of the regulator to the transcription rate of the target gene. Several examples are illustrated to verify that this method is feasible and effective for modeling the GRN and predicting the expression profile in the next cell cycle, the expression profile in the interval between two sample time points or the deficiency data. Additionally, this method provides a general tool for topology estimation of discrete‐time dynamical networks. © 2014 Wiley Periodicals, Inc. Complexity 21: 134–144, 2015
A new adaptive observer design for a class of nonautonomous complex chaotic systems
Authors: Aghababa Mohammad Pourmahmood , Hashtarkhani Bijan
Published: August 2014

This article is concerned with designing of a robust adaptive observer for a class of nonautonomous chaotic system with unknown parameters having unknown bounds. The proposed observer is established from the offered output measurement and robust against model uncertainties and external disturbances. Convergence analysis of the observation error dynamics is realized and proved by Lyapunov stabilization theory. Finally, for verification and demonstration, the proposed method is applied to the Chen as an autonomous chaotic system and the electrostatic transducer as a nonautonomous chaotic system. The numerical simulations illustrate the excellent performance of the proposed scheme. © 2014 Wiley Periodicals, Inc. Complexity 21: 145–153, 2015
Endothelial amine oxidase AOC3 transiently contributes to adaptive immune responses in the airways
Authors: Dunkel Johannes , Aguilar‐Pimentel Juan Antonio , Ollert Markus , Fuchs Helmut , Gailus‐Durner Valerie , de Angelis Martin Hrabě , Jalkanen Sirpa , Salmi Marko , Veres Tibor Z.
Published: August 2014

Amine oxidase, copper containing 3 (AOC3, also known as vascular adhesion protein‐1 (VAP‐1)) is an endothelial adhesion molecule that contributes to the extravasation of neutrophils, macrophages, and lymphocytes to sites of inflammation. However, the role of AOC3/VAP‐1 in allergic responses remains unknown. Here, we studied eosinophil and CD4+ T‐cell recruitment to the airways using AOC3/VAP‐1‐deficient mice. In an OVA‐triggered asthma model, AOC3/VAP‐1 slightly contributed to the accumulation of leukocytes in lungs in an age‐dependent manner. We then established a new model to kinetically measure recruitment of OVA‐specific CD4+ T cells to different airway immune compartments during the priming and effector phases of an adaptive immune response. The results showed that in the absence of AOC3/VAP‐1, recruitment of antigen‐specific CD4+ T cells to draining bronchial lymph nodes is reduced by 89% on day 3 after tracheal allergen exposure, but this difference was not observed on day 6. The dispersal of effector cells to lung and tracheal mucosa is AOC3/VAP‐1 independent. Thus, in allergic airway reactions, AOC3/VAP‐1 transiently contributes to the antigen‐specific, CD4+ T‐cell traffic to secondary lymphatic tissues, but not to airway mucosa or lung parenchyma. Our results suggest a largely redundant function for AOC3/VAP‐1 in allergic inflammatory responses of the airways.
IL‐33 attenuates the development of experimental autoimmune uveitis
Authors: Barbour Mark , Allan Debbie , Xu Heping , Pei Cheng , Chen Mei , Niedbala Wanda , Fukada Sandra Y. , Besnard Anne‐Galle , Alves‐Filho Jose C. , Tong Xiaoguang , Forrester John V. , Liew Foo Yew , Jiang Hui‐Rong
Published: August 2014

Interleukin‐33 (IL‐33) is associated with several important immune‐mediated disorders. However, its role in uveitis, an important eye inflammatory disease, is unknown. Here, we investigated the function of IL‐33 in the development of experimental autoimmune uveitis (EAU). IL‐33 and IL‐33 receptor (ST2) were expressed in murine retinal pigment epithelial (RPE) cells in culture, and IL‐33 increased the expression of Il33 and Mcp1 mRNA in RPE cells. In situ, IL‐33 was highly expressed in the inner nuclear cells of the retina of naïve mice, and its expression was elevated in EAU mice. ST2‐deficient mice developed exacerbated EAU compared with WT mice, and administration of IL‐33 to WT mice significantly reduced EAU severity. The attenuated EAU in IL‐33‐treated mice was accompanied by decreased frequency of IFN‐γ+ and IL‐17+ CD4+ T cells and reduced IFN‐γ and IL‐17 production but with increased frequency of IL‐5+ and IL‐4+ CD4 T cells and IL‐5 production in the draining lymph node and spleen. Macrophages from the IL‐33‐treated mice show a significantly higher polarization toward an alternatively activated macrophage phenotype. Our results therefore demonstrate that the endogenous IL‐33/ST2 pathway plays an important role in EAU, and suggest that IL‐33 represents a potential option for treatment of uveitis.
Rigid–Flexible Hybrid Proton‐Exchange Membranes with Improved Water‐Retention Properties and High Stability for Fuel Cells
Authors: Li Jing , Cai Weiwei , Zhang Yunfeng , Cheng Hansong
Published: August 2014

A novel molecular structural design of rigid–flexible hybrid polymer backbone is proposed for proton‐exchange membranes (PEMs) with the objective to preserve the material longevity by enhancing the dimensional stability. The effect of the rigid–flexible hybrid backbone is demonstrated based on performance tests for a series of non‐fluorinated polyamide–sulfonimide proton conductors, among which the conductivity of the rigid–flexible hybrid structural PEM is nearly 100 % higher than the rigid PEM with almost the same ion‐exchange capacity (IEC). The dimensional and mechanical stabilities of these PEMs are better than those of Nafion membranes. The measured conductivity of the rigid–flexible hybrid structural PEM is on the order of 10−2 S cm−1.
Bed morphological changes around a finite patch of vegetation
Authors: Kim Hyung Suk , Kimura Ichiro , Shimizu Yasuyuki
Published: August 2014

For the appropriate management and restoration of rivers, isolated vegetation is often a practical means for improving stream habitat and ecology. The effect of a finite vegetation patch on flow and bed morphology in an open channel was investigated using laboratory experiments. The patch containing emergent and submerged vegetation was modeled using circular cylinders and located mid‐channel along a side wall. Several configurations of the patch and submergence ratio (i.e. water depth to the height of vegetation), and two flow conditions (i.e. below and above the sediment motion threshold) were considered. For flows below the sediment motion threshold, erosion occurred primarily on the opposite side of the patch and near the leading edge of the patch. The degree of scouring depth observed in both these regions was affected by the submergence ratio and it increased with the non‐dimensional flow blockage (i.e. the product of the patch density and width). In contrast, for flows above the sediment motion threshold, sediment accumulated within and around the patch due to a reduction in bed shear stress, which was strongly influenced by the flow blockage and the obstruction ratio (i.e. the ratio of patch width to channel width). The eroded area observed within the patch was consistent with the interior adjustment region where the deceleration and diversion of flow occurred through the patch. As the flow blockage increased or as the obstruction ratio decreased, the deposition rate within and behind the patch decreased. Furthermore, the deposition rate increased with an increase in the ratio of flow rate through the patch to total flow rate regardless of the submergence ratio. Copyright © 2014 John Wiley & Sons, Ltd.
Smart primary user emulation in cognitive radio networks: defence strategies against radio‐aware attacks and robust spectrum sensing
Authors: Haghighat M. , Sadough S. M. S.
Published: August 2014

Cognitive radio (CR), which provides dynamic spectrum access to combat spectrum scarcity, imposes some emerging threats to the network. One of the common threats in CR is primary user emulation (PUE) attack, in which some malicious users try to mimic primary signal and deceive CR users to prevent them from accessing the vacant frequency bands. In this paper, we propose a smart radio‐aware PUE attacker that is equipped with spectrum sensing and consumes malicious resources in a way that causes more destruction on CR performance than always present PUE attackers. We first analyse and formulate the destructive effect such an attacker imposes to the CR network, and then, we derive robust cooperative spectrum sensing rules for energy detection spectrum sensing under PUE attacks. Moreover, using a weighting vector at fusion centre of the CRs, we propose a scheme to combat fake signals by maximising the average cognitive signal to interference plus noise ratio. We combine proposed method with two widely used energy detection scheme, Neyman–Pearson and minimum probability of error criterion. Numerical results show the superiority and robustness of our proposed method in the presence of smart attackers compared with conventional methods. Copyright © 2014 John Wiley & Sons, Ltd.
Activated recombinant factor VIIa should not be used in patients with refractory variceal bleeding: It is mostly ineffective, is expensive, and may rarely cause serious adverse events
Authors: Sozio Margaret S. , Chalasani Naga
Published: August 2014

Background & Aims: Two randomized controlled studies have evaluated the effect of recombinant Factor VIIa (rFVIIa) on variceal bleeding in cirrhosis without showing significant benefit. The aim of the present study was to perform a meta-analysis of the two trials on individual patient data with special focus on high risk patients. Methods: The primary outcome measure was the effect of rFVIIa on a composite five day endpoint: failure to control bleeding, 5-day rebleeding or death. Analysis was based on intention to treat. High risk was defined as active bleeding on endoscopy while under vasoactive drug infusion and Child-Pugh score >8. Results: 497 patients were eligible for the meta-analysis; 308 (62%) had active variceal bleeding at endoscopy (oozing or spurting) and 283 of these had a Child-Pugh score >8. Analysis on the composite endpoint in all patients with bleeding from oesophageal varices did not show any beneficial treatment effect. However, failure rate for the primary composite end-point was significantly lower in treated patients with active bleeding at endoscopy (17%) compared to placebo (26%,

p

= 0.049). This difference was highly significant in patients with Child-Pugh score >8 and active bleeding at endoscopy (rFVIIa 16%, placebo 27%;

p

= 0.023). No significant treatment effect was found at 42 days. Five thromboembolic events occurred in rFVIIa treated patients compared to none in placebo treated patients. Conclusions: The current meta-analysis shows a beneficial effect of rFVIIa on the primary composite endpoint of control of acute bleeding, prevention of rebleeding day 1-5 and 5-day mortality in patients with advanced cirrhosis and active bleeding from oesophageal varices at endoscopy. A major drawback of the treatment is a potential increased risk of arterial thrombo-embolic events. This treatment might be considered in patients with lack of control of bleeding after standard treatment.
Late diagnosis of hepatitis C virus infection in the Chronic Hepatitis Cohort Study (CHeCS): Missed opportunities for intervention
Authors: Moorman Anne C. , Xing Jian , Ko Stephen , Rupp Loralee B. , Xu Fujie , Gordon Stuart C. , Lu Mei , Spradling Philip R. , Teshale Eyasu H. , Boscarino Joseph A. , Vijayadeva Vinutha , Schmidt Mark A. , Holmberg Scott D. ,   for the CHeCS Investigators
Published: August 2014

To determine the stage of liver disease at initial diagnosis of hepatitis C virus (HCV) infection, we analyzed data from the Chronic Hepatitis Cohort Study (CHeCS), a large U.S. observational study. We examined the temporal relationships of initial HCV infection diagnosis with cirrhosis—defined by liver biopsy or mean FIB‐4 score >5.88—and time to onset of cirrhotic decompensation in electronic medical records. We determined time in the health system prior to HCV diagnosis and rates of hospitalization and death following HCV diagnosis. Of 14,717 patients with chronic HCV seen during 2006‐2011, 6,166 (42%) had a definable time of initial HCV diagnosis. Of these, 1,056 (17%) patients met our definition for “late diagnosis” with either cirrhosis concurrent with initial HCV diagnosis (n = 550), a first diagnosis of hepatic decompensation before or within 12 months after initial HCV diagnosis (n = 506), or both (n = 314). Patients with late diagnosis had an average of 6 years in the health system before their HCV diagnosis. In a comparison with patients without late diagnosis, hospitalization (59% versus 35%) and death (33% versus 9%) were more frequent among patients with late diagnosis. Among all who died, mean (median) time from initial HCV diagnosis to death was 4.8 (4.2) years. Conclusion: Many CHeCS patients had advanced liver disease concurrent with their initial HCV diagnosis despite many years of engagement with the healthcare system, and these patients had high rates of hospitalization and mortality. (Hepatology 2015;61:1479–1484)
TRAIL expression levels in human hepatocellular carcinoma have implications for tumor growth, recurrence and survival
Authors: Piras‐Straub Katja , Khairzada Khaleda , Trippler Martin , Baba Hideo A. , Kaiser Gernot M. , Paul Andreas , Canbay Ali , Weber Frank , Gerken Guido , Herzer Kerstin
Published: August 2014

The proapoptotic molecule TNF‐related apoptosis‐inducing ligand (TRAIL) has earned attention because of its ability to induce apoptosis in liver cancer cells without damaging normal liver cells. It may play an important role in preventing the development and outgrowth of hepatocellular carcinoma (HCC). TRAIL expression was investigated in a large series of human HCCs. We analyzed liver tissue from 108 patients undergoing partial liver resection (PLR) or liver transplantation (LT) because of either HCC or other indications. TRAIL expression was correlated with the cause of liver disease, demographic and clinical variables and pathologic properties. Our analysis found that in 66% of HCCs TRAIL expression was significantly lower than in the surrounding non‐cancerous liver tissue (p ≤ 0.012). Separation by cause of disease showed that HCC TRAIL mRNA expression was lower in almost all groups than in non‐cancerous tissue but most significantly lower in NASH‐associated liver tumors. Interestingly, low HCC TRAIL expression was found to correlate with tumor size (p ≤ 0.007) and stage, as well as with tumor recurrence after resection and poor survival rates. The results of this study suggest that low TRAIL mRNA levels may be both a dominant feature in HCC development and growth and a predictor of tumor recurrence and poorer survival rates.
Data driven analysis of functional brain networks in fMRI for schizophrenia investigation
Authors: Mascolo Luigi , Guccione Pietro , Nico Giovanni , Taurisano Paolo , Fazio Leonardo
Published: August 2014

The purpose of this article is to present a methodology to identify the sources of activity in brain networks from functional magnetic resonance imaging (fMRI) data using the multiset canonical correlation analysis algorithm. The aim is to lay the foundations for a screening marker to be used as indicator of mental diseases. Group analysis blind source separation methods have proved reliable to extract the latent sources underlying the brain activities but currently there is no recognized biomarker for mental disorders. Recent studies have identified alterations in the so called default mode network (DMN) that are common to several neuropsychiatric disorders, including schizophrenia. In particular, here we account for the hypothesis that the alterations in the DMN activity can be effectively highlighted by analyzing the transient states between two different tasks. A set of fMRI data acquired from 18 subjects performing working memory tasks is investigated for such purpose. Subjects are patients affected by schizophrenia for one half and healthy control subjects for the other. Under these conditions, the proposed methodology provides high discrimination performances in terms of classification error, thereby providing promising results for a preliminary tool able to monitor the disease state or to perform a prescreening for patients at risk for schizophrenia. © 2014 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 24, 239–248, 2014
Statistically quantified measurement of an Alzheimer's marker by surface‐enhanced Raman scattering
Authors: Buividas Ričardas , Dzingelevičius Nerijus , Kubiliūtė Reda , Stoddart Paul R. , Khanh Truong Vi , Ivanova Elena P. , Juodkazis Saulius
Published: August 2014

Fibrillar forms of the Amyloid‐β (Aβ) protein have been implicated in the early stages of Alzheimer's disease (AD), however there are no standardised assays for soluble Aβ oligomer biomarkers that provide the best indication of the disease progression [1,2]. As a step towards a fast and label‐free method for testing different AD biomarkers, we have combined laser nano‐textured substrates with a SERS mapping technique and validated it using soluble Aβ‐40 oligomers [3‐5]. The nano‐textured SERS substrates provide fast (&5 min), label‐free spectra associated with soluble Aβ‐40 oligomers down to a concentration of 10 nM. Statistical analysis of the spectral intensities mapped over the substrate surface shows a quantitative correlation with the oligomer concentration.

Schematics of experiments: SERS mapping of Aβ‐40 (left figure: measured SERS intensity overlayed with an SEM image of ripples) was carried out on the laser nano‐textured (ripple) surface of sapphire and statistical analysis of the SERS intensity was carried out for qualitative (a high SERS intensity at low probability) and quantitative (a moderate SERS intenisty at the highest probability) measures. Quantitative statistical analysis of SERS mapping data can be performed off line for cross correlations with other known SERS signatures.

magnified image

Schematics of experiments: SERS mapping of Aβ‐40 (left figure: measured SERS intensity overlayed with an SEM image of ripples) was carried out on the laser nano‐textured (ripple) surface of sapphire and statistical analysis of the SERS intensity was carried out for qualitative (a high SERS intensity at low probability) and quantitative (a moderate SERS intenisty at the highest probability) measures. Quantitative statistical analysis of SERS mapping data can be performed off line for cross correlations with other known SERS signatures.
Rats' choices with token stimuli in concurrent variable‐interval schedules
Authors: Mazur James E.
Published: August 2014

Four rats responded on concurrent variable‐interval schedules that delivered token stimuli (stimulus lights arranged vertically above each of two side levers). During exchange periods, each token could be exchanged for one food pellet by responding on a center lever, with one response required for each pellet delivery. In different conditions, the exchange requirements (number of tokens that had to be earned before they could be exchanged for food) varied between one and four for the two response levers. The experiments were closely patterned after research with pigeons by Mazur and Biondi (), and the results from the rats in the present experiment were similar. Response percentages on the two levers changed as each additional token was earned, and these patterns indicated that choice was controlled by both the time to the exchange periods and the number of food pellets that were delivered in the exchange period. In some conditions, the exchange requirement was three tokens for each lever, but the token lights were not turned on as they were earned for one of the two keys. The rats showed a slight preference for the lever without the token lights, which may indicate that the token lights were not serving as conditioned reinforcers (a result also found by Mazur and Biondi with pigeons). Overall, these results suggest that, in this choice procedure, the token stimuli served primarily as discriminative stimuli that signaled the temporal proximity and quantity of the primary reinforcer, food.