bluuebunny/crossref_metadata_2025 huggingface dataset:
HIV Fusion in Dendritic Cells Occurs Mainly at the Surface and Is Limited by Low CD4 Levels
Authors: Chauveau Lise , Donahue Daniel Aaron , Monel Blandine , Porrot Francoise , Bruel Timothée , Richard Lea , Casartelli Nicoletta , Schwartz Olivier
Published: August 2017

HIV-1 poorly infects monocyte-derived dendritic cells (MDDCs). This is in large part due to SAMHD1, which restricts viral reverse transcription. Pseudotyping HIV-1 with vesicular stomatitis virus G protein (VSV-G) strongly enhances infection, suggesting that earlier steps of viral replication, including fusion, are also inefficient in MDDCs. The site of HIV-1 fusion remains controversial and may depend on the cell type, with reports indicating that it occurs at the plasma membrane or, conversely, in an endocytic compartment. Here, we examined the pathways of HIV-1 entry in MDDCs. Using a combination of temperature shift and fusion inhibitors, we show that HIV-1 fusion mainly occurs at the cell surface. We then asked whether surface levels or intracellular localization of CD4 modulates HIV-1 entry. Increasing CD4 levels strongly enhanced fusion and infection with various HIV-1 isolates, including reference and transmitted/founder strains, but not with BaL, which uses low CD4 levels for entry. Overexpressing coreceptors did not facilitate viral infection. To further study the localization of fusion events, we generated CD4 mutants carrying heterologous cytoplasmic tails (LAMP1 or Toll-like receptor 7 [TLR7]) to redirect the molecule to intracellular compartments. The intracellular CD4 mutants did not facilitate HIV-1 fusion and replication in MDDCs. Fusion of an HIV-2 isolate with MDDCs was also enhanced by increasing surface CD4 levels. Our results demonstrate that MDDCs are inefficiently infected by various HIV-1 and HIV-2 strains, in part because of low CD4 levels. In these cells, viral fusion occurs mainly at the surface, and probably not after internalization.

IMPORTANCEDendritic cells (DCs) are professional antigen-presenting cells inducing innate and adaptive immune responses. DCs express the HIV receptor CD4 and are potential target cells for HIV. There is debate about the sensitivity of DCs to productive HIV-1 and HIV-2 infection. The fusion step of the viral replication cycle is inefficient in DCs, and the underlying mechanisms are poorly characterized. We show that increasing the levels of CD4 at the plasma membrane allows more HIV fusion and productive infection in DCs. We further demonstrate that HIV fusion occurs mainly at the cell surface and not in an intracellular compartment. Our results help us understand why DCs are poorly sensitive to HIV infection.
Structural Characterization of Acidic M17 Leucine Aminopeptidases from the TriTryps and Evaluation of Their Role in Nutrient Starvation in Trypanosoma brucei
Authors: Timm Jennifer , Valente Maria , García-Caballero Daniel , Wilson Keith S. , González-Pacanowska Dolores
Published: August 2017

Leucine aminopeptidases (LAPs) catalyze the hydrolysis of the N-terminal amino acid of peptides and are considered potential drug targets. They are involved in multiple functions ranging from host cell invasion and provision of essential amino acids to site-specific homologous recombination and transcription regulation. In kinetoplastid parasites, there are at least three distinct LAPs. The availability of the crystal structures provides important information for drug design. Here we report the structure of the acidic LAPs from three kinetoplastids in complex with different inhibitors and explore their role in
Trypanosoma brucei
survival under various nutrient conditions. Importantly, the acidic LAP is dispensable for growth both
in vitro
and
in vivo
, an observation that questions its use as a specific drug target. While LAP-A is not essential, leucine depletion and subcellular localization studies performed under starvation conditions suggest a possible function of LAP-A in the response to nutrient restriction.
The volume of peripapillary vessels within the retinal nerve fibre layer: an optical coherence tomography angiography study of normal subjects
Authors: Allegrini Davide , Montesano Giovanni , Fogagnolo Paolo , Pece Alfredo , Riva Roberta , Romano Mario R , Rossetti Luca
Published: August 2017

Background/aims

To investigate the contribution of vascular volume calculated by optical coherence tomography angiography (OCTA) to the measurement of peripapillary retinal nerve fibre layer (RNFL) thickness.

Methods

We used OCTA scans to build volumetric maps of the RNFL angiograms by thresholding the decorrelation images and summing the number of white pixels along the z-axis at each location. We used these maps to calculate the contribution of the vascular tissue to the RNFL thickness.

Results

We analysed 51 eyes from 36 subjects. The mean RNFL volume calculated on the peripapillary region was 0.607±0.045 mm3 and the mean vessel volume was 0.217±0.035 mm3, with a mean vessel/total RNFL ratio of 35.627%±3.942%. When evaluated in the peripapillary circular section, the total contribution of the vascular tissue to the global RNFL thickness was 29.071%±3.945%. The superior and inferior sectors showed the highest percentage of vascular tissue within the RNFL circular profile (31.369% and 34.788% respectively).

Conclusions

We found that the vascular contribution to the RNFL thickness is 29.07±3.945%. This is much higher than what has been reported from calculations made on the structural OCT alone (13% reported by Hood et al and 11.3%±1.6% for the Cirrus OCT and 11.8%±1.4% for the Spectralis OCT reported by Patel et al). We conclude that evaluation of the vascular tissue contribution to the RNFL thickness with OCTA might be useful when performing precise quantification of the neuronal tissue.
Intravitreal bevacizumab monotherapy in myopic choroidal neovascularisation: 5-year outcomes for the PAN-American Collaborative Retina Study Group
Authors: Chhablani Jay , Paulose Remya Mareen , Lasave Andres F , Wu Lihteh , Carpentier Cristian , Maia Mauricio , Lujan Silvio , Rojas Sergio , Serrano Martin , Berrocal Maria H , Arevalo J Fernando
Published: August 2017

Purpose

To report the long-term anatomical and visual outcomes of intravitreal bevacizumab (IVB) monotherapy in naive choroidal neovascularisation (CNV) caused by myopia.

Methods

Retrospective analysis of naive CNV secondary to myopia that underwent antivascular endothelial growth factor monotherapy was performed. Collected data included demographic details, clinical examination details including visual acuity at presentation and follow-up with imaging and treatment details. Main outcome measures were resolution of CNV activity at the last visit. Secondary outcomes included change in visual acuity, number of injections and adverse events.

Results

Thirty-three eyes of 31 subjects with a mean age of 51.48±16.4 years were included. The mean follow-up was 66.47 months. 27 eyes had type 2 CNV and the rest seven eyes had type 1 CNV. The mean number of IVB injections per eye was 4.9. Mean visual acuity at baseline reduced from 0.65±0.33 logMAR units (Snellen equivalent=20/89) to 0.73±0.50 logMAR units (20/107) at final follow-up (p=0.003). The mean central macular thickness decreased from 309.31±86 µm at baseline to 267.5±70.89 µm at the last visit (p=0.03). However, visual acuity was maintained (±1 line of baseline) in 13 eyes (39.4%), ≥2 line improvement in nine (27.3%) eyes and more than two lines worsening in 11 eyes (33.3%). Foveal atrophy was observed at baseline and last visit in 6 (12.5%) and 14 (29.1%), respectively (p=0.007). No systemic adverse events were observed.

Conclusion

IVB monotherapy is safe and effective for long-term treatment of CNV secondary to myopia in real life.
Identification of imaging features that determine quality and repeatability of retinal capillary plexus density measurements in OCT angiography
Authors: Fenner Beau J , Tan Gavin S W , Tan Anna C S , Yeo Ian Y S , Wong Tien Yin , Cheung Gemmy C M
Published: August 2017

Purpose

Optical coherence tomography angiography (OCT-A) potentially allows for rapid and non-invasive quantification of retinal capillary plexus density in various disease states. This study aims to identify the key features that influenced the repeatability of OCT-A measurements.

Methods

We obtained OCT-A images on two separate visits in 44 healthy eyes from 44 subjects, each imaged with using the Topcon DRI OCT Triton imaging system. The parafoveal vessel density within a 1.5 mm radius centred over the fovea was obtained with the built-in tool for the superficial and deep retinal plexuses. Repeatability of vessel density was determined by intraclass correlation (ICC) and mean variation. We evaluated several image parameters to determine their influence on the repeatability of vessel density measurement in each of the two capillary plexuses.

Results

The mean age of the subjects was 70.2±9.2 years, with 64% males. Mean parafoveal vessel density measurements for the first and second visits were 53.3±11.1 and 53.3±10.3 for the superficial plexus and 27.3±8.59 and 27.0±8.78 for the deep plexus. ICC analyses demonstrated that high fine vessel visibility, the absence of motion artefact and software-derived image quality score of 60 or above were necessary to obtain a good (ICC>0.6) or excellent (ICC>0.75) repeatability.

Conclusions

Our study identified the imaging parameters that determined the repeatability of quantitative retinal vessel density measurements. These findings have implications in determining if OCT-A images can be used to accurately evaluate serial changes in retinal vessel density.
Examining self-reported and biological stress and near misses among Emergency Medicine residents: a single-centre cross-sectional assessment in the USA
Authors: Arnetz Bengt B , Lewalski Philip , Arnetz Judy , Breejen Karen , Przyklenk Karin
Published: August 2017

Objectives

To examine the relationship between perceived and biological stress and near misses among Emergency Medicine residents.

Design

Self-rated stress and stress biomarkers were assessed in residents in Emergency Medicine before and after a day shift. The supervising physicians and residents reported numbers of near misses.

Setting

The study took place in the Emergency Department of a large trauma 1 centre, located in Detroit, USA.

Participants

Residents in Emergency Medicine volunteered to participate. The sample consisted of 32 residents, with complete data on 28 subjects. Residents’ supervising physicians assessed the clinical performance of each resident.

Primary and secondary outcome measures

Participants’ preshift and postshift stress, biological stress (salivary cortisol, plasma interleukin-6, tumour necrosis factor-alpha (TNF-α) and high-sensitivity C-reactive protein), residents’ and supervisors’ reports of near misses, number of critically ill and patients with trauma seen during the shift.

Results

Residents’ self-reported stress increased from an average preshift level of 2.79 of 10 (SD 1.81) to a postshift level of 5.82 (2.13) (p<0.001). Residents cared for an average of 2.32 (1.52) critically ill patients and 0.68 (1.06) patients with trauma. Residents reported a total of 7 near misses, compared with 11 reported by the supervising physicians. After controlling for baseline work-related exhaustion, residents that cared for more patients with trauma and had higher levels of TNF-α reported a higher frequency of near misses (R2=0.72; p=0.001). Residents’ preshift ratings of how stressful they expected the shift to be were related to the supervising physicians’ ratings of residents’ near misses during the shift.

Conclusion

Residents’ own ratings of near misses were associated with residents’ TNF-α, a biomarker of systemic inflammation and the number of patients with trauma seen during the shift. In contrast, supervisor reports on residents’ near misses were related only to the residents’ preshift expectations of how stressful the shift would be.
Effect of patient weight on first pass success and neuromuscular blocking agent dosing for rapid sequence intubation in the emergency department
Authors: Patanwala Asad E , Sakles John C
Published: August 2017

Objectives

The primary objective of this study was to determine the association between patient weight and first pass success (FPS) during rapid sequence intubation (RSI) in the ED. The secondary objective was to evaluate the association between patient weight and neuromuscular blocking agent (NMBA) dosing.

Methods

This was a retrospective cohort study conducted in a tertiary care academic ED. Consecutive adult patients who underwent RSI in the ED between January 2014 and June 2016 were included. Data were collected on patient, operator and procedural characteristics. The cohort was categorised into the following weight strata: <80 kg, 80 to <100 kg, 100 to <120 kg and ≥120 kg. The primary outcome of interest was FPS. A multivariable logistic regression analysis was conducted to evaluate the relationship between patient weight category and FPS. NMBA dosing was reported descriptively.

Results

The sample included 891 patients. FPS for each weight category was as follows: <80 kg (91%), 80 to <100 kg (90%), 100 to <120 kg (91%) and ≥120 kg (76%). After adjusting for potential confounders, the heaviest weight category was associated with decreased odds of FPS (OR 0.2, 95% CI 0.1 to 0.5, p<0.001). Median doses for succinylcholine (based on total body weight) decreased as weight increased: <80 kg (1.5 mg/kg), 80 to <100 kg (1.3 mg/kg), 100 to <120 kg (1.2 mg/kg) and ≥120 kg (1.0 mg/kg). Median doses for rocuronium (based on ideal body weight) were similar across weight categories: <80 kg (1.3 mg/kg), 80 to <100 kg (1.4 mg/kg), 100 to <120 kg (1.3 mg/kg) and ≥120 kg (1.4 mg/kg).

Conclusions

Very heavy patients (>120 kg) undergoing RSI in the ED had a reduced FPS, and succinylcholine was more commonly underdosed than rocuronium in the heavier weight group.
Plausibility criteria for putative pathophysiological mechanisms in functional gastrointestinal disorders: a consensus of experts
Authors: Tack Jan , Corsetti Maura , Camilleri Michael , Quigley Eamonn MM , Simren Magnus , Suzuki Hidekazu , Talley Nicholas J , Tornblom Hans , Van Oudenhove Lukas
Published: August 2017

Background and aims

The functional gastrointestinal disorders (FGIDs) are extremely common conditions associated with a considerable personal, social and health economic burden. Managing FGIDs in clinical practice is challenging because of the uncertainty of symptom-based diagnosis, the high frequency of overlap between these conditions and the limited efficacy of available therapies. It has often been argued that successful drug development and management of FGIDs requires knowledge of the underlying pathophysiology. Numerous and highly variable candidate pathophysiological mechanisms have been implicated in the generation of FGID symptoms, but there is no current consensus on how to best define the relevance of these disturbances.

Methods

A group of international experts on FGIDs developed plausibility criteria that should be fulfilled by relevant pathophysiological mechanisms in FGIDs.

Results

Five criteria are proposed: (1) the presence of the abnormality in a subset of patients, (2) temporal association between proposed mechanism and symptom(s), (3) correlation between the level of impairment of the mechanism and symptom(s), (4) induction of the symptom(s) by provoking the pathophysiological abnormality in healthy subjects and (5) treatment response by a therapy specifically correcting the underlying disorder or congruent natural history of symptoms and dysfunction in the absence of specific therapy. Based on strength of evidence for these five criteria according to the Grading of Recommendations Assessment, Development and Evaluation system, a plausibility score can be calculated for each mechanism.

Conclusion

Evaluation of the strength of evidence for candidate pathophysiological abnormalities fulfilling these five plausibility criteria will help to identify the most relevant mechanisms to target for novel diagnostic approaches and for the development of new therapies.
Efficacy of embedded nurse-led versus conventional physician-led follow-up in rheumatoid arthritis: a systematic review and meta-analysis
Authors: de Thurah Annette , Esbensen Bente Appel , Roelsgaard Ida Kristiane , Frandsen Tove Faber , Primdahl Jette
Published: August 2017

Objective

To compare the efficacy of embedded nurse-led versus conventional physician-led follow-up on disease activity in patients with rheumatoid arthritis (RA).

Methods

In a systematic literature search, we identified randomised controlled trials (RCTs) reporting on the efficacy of nurse-led follow-up on disease control in patients with RA compared with physician-led follow-up. Primary outcome was disease activity indicated by Disease Activity Score (DAS)-28. Secondary outcomes were: patient satisfaction, physical disability, fatigue, self-efficacy and quality of life. Outcomes were assessed after 1-year and 2 year follow-ups.

Results

Seven studies representing five RCTs, including a total of 723 participants, were included. All but one study included stable patients in low disease activity or remission at baseline. No difference in DAS-28 was found after 1 year (mean difference (MD) −0.07 (95% CI −0.23 to 0.09)). After 2 years, a statistically significant difference was seen in favour of nurse-led follow-up (MD −0.28 (95% CI −0.53 to −0.04)). However, the difference did not reach a clinically relevant level.

No difference was found in patient satisfaction after 1 year (standard mean difference (SMD) −0.17 (95 % CI −1.0 to 0.67), whereas a statistical significant difference in favour of nurse-led follow-up was seen after 2 years (SMD: 0.6 (95% CI –0.00 to 1.20)).

Conclusion

After 1 year no difference in disease activity, indicated by DAS-28, were found between embedded nurse-led follow-up compared with conventional physician-led follow-up, in RA patients with low disease activity or remission.
Achilles enthesitis defined by ultrasound is not associated with clinical enthesitis in patients with psoriatic arthritis
Authors: Michelsen Brigitte , Diamantopoulos Andreas P , Soldal Dag Magnar , Hammer Hilde Berner , Kavanaugh Arthur , Haugeberg Glenn
Published: August 2017

Objective

To compare clinical and ultrasonographic (US) evaluation of Achilles enthesitis in patients with psoriatic arthritis (PsA).

Methods

The Achilles insertion of outpatients with PsA was examined by clinical assessment of tenderness and US evaluation of (1) inflammatory activity (defined as the presence of power Doppler signal, tendon thickening and/or hypoechogenicity) and (2) structural damage (defined as the presence of erosions, calcifications and/or enthesophytes). Univariate and multivariate logistic regression analyses were performed0.4 to explore the associations between clinical characteristics and US scores.

Results

282 Achilles tendons in 141 patients with PsA were assessed. Mean (SD) age was 52.4 (10.2) years, disease duration 9.5 (6.6) years and 50.4% were females. Palpatory tenderness was found in 88 (31.2%), US-verified inflammatory activity in 46 (16.3%) and structural damage in 148 (52.5%) of the Achilles. Total US scores, as well as their components, were similar for patients with and without palpatory tenderness. None of the clinical characteristics were associated with inflammatory activity. Age, body mass index (BMI), regular physical exercise and current use of biological disease-modifying antirheumatic drugs (bDMARDs) were associated with structural damage.

Conclusion

There appears to be a lack of association between clinical and US signs of Achilles enthesitis in PsA. Age, BMI, regular physical exercise and current use of bDMARDs were associated with structural damage on US.
Working in cold environment and risk of developing rheumatoid arthritis: results from the Swedish EIRA case–control study
Authors: Zeng Pingling , Bengtsson Camilla , Klareskog Lars , Alfredsson Lars
Published: August 2017

Objectives

To investigate (1) whether working in cold environment (WCE) is associated with an increased risk of developing rheumatoid arthritis (RA) (overall), anticitrullinated protein antibody (ACPA)-positive RA and ACPA-negative RA and (2) whether WCE interacts with occupational physical workload in conferring RA risk.

Methods

Data from the Swedish population-based case-control study Epidemiological Investigation of Rheumatoid Arthritis involving 3659 incident cases and 5925 controls were analysed. Study participants were asked whether they had ever worked in cold/outdoor environment along with their exposure duration and frequency. Occurrence of RA among exposed and unexposed subjects were compared by calculating ORs with 95% CI using logistic regression. Additive interactions between WCE and six types of physical workload were assessed using the principle of departure from additivity by calculating attributable proportion due to interaction (AP).

Results

The OR associated with having ever worked in cold environment was 1.5 (95% CI 1.4 to 1.7) for RA (overall), 1.6 (95% CI 1.4 to 1.8) for ACPA-positive RA and 1.4 (95% CI 1.2 to 1.6) for ACPA-negative RA. The risk of developing RA increased with increasing cumulative dose of working in cold indoor environment (p value <0.001), but not working in cold outdoor environment. Positive additive interaction was observed between WCE and repetitive hand/finger movements (AP 0.3 (95% CI 0.1 to 0.5)).

Conclusions

WCE is associated with increased risk of developing both ACPA-positive and ACPA-negative RA. A dose–response relationship was found between working in cold indoor environment and risk of developing RA. Moderate additive interaction was observed between exposure to cold environment and exposure to repetitive hand/finger movements.
Evaluation of the electron transfer flavoprotein as an antibacterial target in Burkholderia cenocepacia
Authors: Stietz Maria S. , Lopez Christina , Osifo Osasumwen , Tolmasky Marcelo E. , Cardona Silvia T.
Published: August 2017

There are hundreds of essential genes in multidrug-resistant bacterial genomes, but only a few of their products are exploited as antibacterial targets. An example is the electron transfer flavoprotein (ETF), which is required for growth and viability in Burkholderia cenocepacia. Here, we evaluated ETF as an antibiotic target for Burkholderia cepacia complex (Bcc). Depletion of the bacterial ETF during infection of Caenorhabditis elegans significantly extended survival of the nematodes, proving that ETF is essential for survival of B. cenocepacia in this host model. In spite of the arrest in respiration in ETF mutants, the inhibition of etf expression did not increase the formation of persister cells, when treated with high doses of ciprofloxacin or meropenem. To test if etf translation could be inhibited by RNA interference, antisense oligonucleotides that target the etfBA operon were synthesized. One antisense oligonucleotide was effective in inhibiting etfB translation in vitro but not in vivo, highlighting the challenge of reduced membrane permeability for the design of drugs against B. cenocepacia. This work contributes to the validation of ETF of B. cenocepacia as a target for antibacterial therapy and demonstrates the utility of a C. elegans liquid killing assay to validate gene essentiality in an in vivo infection model.
Epileptic Seizure Prediction Using Diffusion Distance and Bayesian Linear Discriminate Analysis on Intracranial EEG
Authors: Yuan Shasha , Zhou Weidong , Chen Liyan
Published: August 2017

Epilepsy is a chronic neurological disorder characterized by sudden and apparently unpredictable seizures. A system capable of forecasting the occurrence of seizures is crucial and could open new therapeutic possibilities for human health. This paper addresses an algorithm for seizure prediction using a novel feature — diffusion distance (DD) in intracranial Electroencephalograph (iEEG) recordings. Wavelet decomposition is conducted on segmented electroencephalograph (EEG) epochs and subband signals at scales 3, 4 and 5 are utilized to extract the diffusion distance. The features of all channels composing a feature vector are then fed into a Bayesian Linear Discriminant Analysis (BLDA) classifier. Finally, postprocessing procedure is applied to reduce false prediction alarms. The prediction method is evaluated on the public intracranial EEG dataset, which consists of 577.67[Formula: see text]h of intracranial EEG recordings from 21 patients with 87 seizures. We achieved a sensitivity of 85.11% for a seizure occurrence period of 30[Formula: see text]min and a sensitivity of 93.62% for a seizure occurrence period of 50[Formula: see text]min, both with the seizure prediction horizon of 10[Formula: see text]s. Our false prediction rate was 0.08/h. The proposed method yields a high sensitivity as well as a low false prediction rate, which demonstrates its potential for real-time prediction of seizures.
Uncertainty and sensitivity analysis to complex systems
Authors: Zhu Yueying , Wang Qiuping Alexandre , Li Wei , Cai Xu
Published: August 2017

In the complexity modeling, variance decomposition technique is widely used for the quantification of the variation in the output variables explained by covariates. In this work, the satisfaction of sampling-based variance decomposition strategy (SVDS) is firstly testified in the implementation of an analytic method for uncertainty and sensitivity analysis (UASA) of complex systems. Results suggest that SVDS may overvalue the impacts from individual covariates alone but underestimate the effects from their interactions when the model under discussion involves the interaction effects of nonlinear problems of individual covariates. Following the phenomenon, a modification of SVDS is proposed to generate sensitivity measures that well coincide with the analytic method. The testified strategy, together with our proposed modification, is then employed to clarify the roles of infectious rate and recovered rate, as well as of their interaction, in the estimation of equilibrium state (ES) for both SIR and SIS models. Results demonstrate that infectious and recovered rates almost play the same roles less crucial than that acted by the initial susceptible individuals in the decision of ES for SIR model, accompanied by a fragile contribution from their interactions; while in SIS model, infectious rate is more robust than recovered rate, and their interaction effect is also non-ignorable.
Simulation study of the effect of strain rate on the mechanical properties and tensile deformation of gold nanowire
Authors: Shi Guo-Jie , Wang Jin-Guo , Hou Zhao-Yang , Wang Zhen , Liu Rang-Su
Published: August 2017

The mechanical properties and deformation mechanisms of Au nanowire during the tensile processes at different strain rates are revealed by the molecular dynamics method. It is found that the Au nanowire displays three distinct types of mechanical behaviors when tensioning at low, medium and high strain rates, respectively. At the low strain rate, the stress–strain curve displays a periodic zigzag increase–decrease feature, and the plastic deformation is resulted from the slide of dislocation. The dislocations nucleate, propagate, and finally annihilate in every decreasing stages of stress, and the nanowire always can recover to FCC-ordered structure. At the medium strain rate, the stress–strain curve gently decreases during the plastic process, and the deformation is contributed from sliding and twinning. The dislocations formed in the yield stage do not fully propagate and further escape from the nanowire. At the high strain rate, the stress-strain curve wave-like oscillates during the plastic process, and the deformation is resulted from amorphization. The FCC atoms quickly transform into disordered amorphous structure in the yield stage. The relative magnitude between the loading velocity of strain and the propagation velocity of phonons determines the different deformation mechanisms. The mechanical behavior of Au nanowire is similar to Ni, Cu and Pt nanowires, but their deformation mechanisms are not completely identical with each other.
Maximum Non-Gaussianity Estimation Revisit: Uniqueness Analysis from the Perspective of Constrained Cost Function Optimization
Authors: Wang Gang , Ma Runnian , Meng Qingwei , Liu Wenbin
Published: August 2017

In independent component analysis (ICA) and its diverse algorithms, uniqueness is the most essential requirement and rationality problem compared with performances of existence, stability and convergence. For ICA’s maximum non-Gaussianity estimation (MNE), many achievements have been made in recent twenty years based on uniqueness assumption, which has been taken for granted all along except for some intuitive interpretation. From the perspective of constrained cost function optimization, the paper is to provide a mathematical proof for uniqueness principle in MNE. The research focuses on skewless assumption and kurtosis-based cost function with basic linear ICA model. The relationship between the Kuhn–Tucker (K–T) points of cost function and the local maxima of non-Gaussianity are derived with the help of constrained optimization theory, and then a conclusion is drawn that there is a one-to-one correspondence between independent components and the local maxima, i.e. maximum non-Gaussianity is the sufficient and necessary condition for independent sources recovery. Moreover, the result also leads to an alternative and straightforward approach to the proof of Xu’ one-bit-matching conjecture for the availability of multi-unit approaches.
Additional cases of positive twisted torus knots
Authors: Amoranto Evan , Doleshal Brandy , Rathbun Matt
Published: August 2017

A twisted torus knot is a knot obtained from a torus knot by twisting adjacent strands by full twists. The twisted torus knots lie in [Formula: see text], the genus 2 Heegaard surface for [Formula: see text]. Primitive/primitive and primitive/Seifert knots lie in [Formula: see text] in a particular way. Dean gives sufficient conditions for the parameters of the twisted torus knots to ensure they are primitive/primitive or primitive/Seifert. Using Dean’s conditions, Doleshal shows that there are infinitely many twisted torus knots that are fibered and that there are twisted torus knots with distinct primitive/Seifert representatives with the same slope in [Formula: see text]. In this paper, we extend Doleshal’s results to show there is a four parameter family of positive twisted torus knots. Additionally, we provide new examples of twisted torus knots with distinct representatives with the same surface slope in [Formula: see text].
The Reasons for the Increase in Self-Organization in Companies
Authors: Gazizulina Albina , Eskina Elena , Vasilieva Irina , Valeeva Olga
Published: August 2017

Self-organization is an important factor in the processes of quality management systems. The advantage of self-organization processes is that these processes have a certain stability and adaptability to the environment. The knowledge of fundamental regularities of self-organization allows the designing of active artificial environments, activities of which can result in the formation of desired structures. For example, changes in customers’ requirements can make necessary additional professional development for employees, introduction of benchmarking procedures etc. Self-organization, enables the process ability to enhance its structure and implementation technology depending on the environment. Formally, self-organization model is described as follows. Quality management process is represented as a model of a complex system with input values (such as requirements to the quality level [Formula: see text] and managing actions [Formula: see text]) and output signals (such as multiple factors of a process quality [Formula: see text]). Development of quality management system processes in the mechanical engineering industry (complication of a structure or production technology, etc.) is realized considerably by using self-organization principles. By analyzing the causes of self-organizational processes development, we can conclude that a fundamental factor for that process is the desire to improve the competitiveness of an organization which implies the development of effective quality management system.
Multi Release Cost Model — A New Perspective
Authors: Mishra Gaurav , Kapur P. K. , Shrivastava A. K.
Published: August 2017

Software testing plays a crucial role in software development process to achieve high quality software. Increased demand for new features, market competition, time and resource limitation has shortened the software lifecycle. To be in the market, software companies have to release new versions of software with new functionalities. Many ideologies and cost models have been formulated in the past decades with the idea of when to release the software for single and multi-versions. In the existing literature, the total debugging cost for the first version and next versions includes the cost of debugging in the operational phase along with the testing cost. It is assumed that the software is supported until the operational phase is over. Also, it is considered that some of the remaining faults of the previous release are reported and removed during the testing period of the new versions, which shows the repetition of cost for debugging the remaining number of faults of the previous release and results as increased cost of the software for the next release. In the present paper, we provide a new perspective on the release cost. To overcome the above problem in this paper, we describe a generalized cost model in which the remaining faults of the current version are removed during the operational phase of the current version and partly in the testing period of the next version. Application of the proposed cost model is shown on a real fault counting data for multi-versions of a software.
Reliability Estimation for the Two-Parameter Exponential Family Based on Progressively Type-II Censored Data
Authors: Gui Wenhao
Published: August 2017

In this paper, we deal with the problem of estimating the reliability function of the two-parameter exponential distribution. Classical Maximum likelihood and Bayes estimates for one and two parameters and the reliability function are obtained on the basis of progressively type-II censored samples. The inverted gamma conjugate prior density is assumed for the one-parameter case, whereas the joint prior density of the two-parameter case is composed of the inverted gamma and the uniform densities. A comparison between the obtained estimators is made through a Monte Carlo simulation study. A real example is used to illustrate the proposed methods.
G-marked moduli spaces
Authors: Li Binru
Published: August 2017

The aim of this paper is to investigate the closed subschemes of moduli spaces corresponding to projective varieties which admit an effective action by a given finite group [Formula: see text]. To achieve this, we introduce the moduli functor [Formula: see text] of [Formula: see text]-marked Gorenstein canonical models with Hilbert polynomial [Formula: see text], and prove the existence of [Formula: see text], the coarse moduli scheme for [Formula: see text]. Then we show that [Formula: see text] has a proper and finite morphism onto [Formula: see text] so that its image [Formula: see text] is a closed subscheme. In the end we obtain the canonical representation type decomposition [Formula: see text] of [Formula: see text] and use [Formula: see text] to study the structure of [Formula: see text].
Global blowup controllability of heat equation with feedback control
Authors: Lin Ping
Published: August 2017

This paper concerns a global controllability problem for heat equations. In the absence of control, the solution to the linear heat system globally exists. While for each initial data, we can find a feedback control acting on an internal subset of the space domain such that the corresponding solution to the system blows up at given time.
Adams inequality with exact growth in the hyperbolic space ℍ4 and Lions lemma
Authors: Karmakar Debabrata
Published: August 2017

In this paper, we prove Adams inequality with exact growth condition in the four-dimensional hyperbolic space [Formula: see text] [Formula: see text] [Formula: see text]. We will also establish an Adachi–Tanaka-type inequality in this setting. Another aspect of this paper is the Lions lemma in the hyperbolic space. We prove Lions lemma for the Moser functional and for a few cases of the Adams functional on the whole hyperbolic space.
The polynomial growth solutions to some sub-elliptic equations on the Heisenberg group
Authors: Liu Hairong , Long Tian , Yang Xiaoping
Published: August 2017

We give an explicit description of polynomial growth solutions to some sub-elliptic operators of divergence form with [Formula: see text]-periodic coefficients on the Heisenberg group, where the periodicity has to be meant with respect to the Heisenberg geometry. We show that the polynomial growth solutions are necessarily polynomials with [Formula: see text]-periodic coefficients. We also prove the Liouville-type theorem for the Dirichlet problem to these sub-elliptic equations on an unbounded domain on the Heisenberg group, show that any bounded solution to the Dirichlet problem must be constant.
On Auslander’s formula and cohereditary torsion pairs
Authors: Banerjee Abhishek
Published: August 2017

For a small abelian category [Formula: see text], Auslander’s formula allows us to express [Formula: see text] as a quotient of the category [Formula: see text] of coherent functors on [Formula: see text]. We consider an abelian category with the added structure of a cohereditary torsion pair [Formula: see text]. We prove versions of Auslander’s formula for the torsion-free class [Formula: see text] of [Formula: see text], for the derived torsion-free class [Formula: see text] of the triangulated category [Formula: see text] as well as the induced torsion-free class in the ind-category [Formula: see text] of [Formula: see text]. Further, for a given regular cardinal [Formula: see text], we also consider the category [Formula: see text] of [Formula: see text]-presentable objects in the functor category [Formula: see text]. Then, under certain conditions, we show that the torsion-free class [Formula: see text] can be recovered as a subquotient of [Formula: see text].
Quasi-particles in the principal picture of 𝔰𝔩̂2 and Rogers–Ramanujan-type identities
Authors: Kožić Slaven , Primc Mirko
Published: August 2017

In their seminal work Lepowsky and Wilson gave a vertex-operator theoretic interpretation of Gordon–Andrews–Bressoud’s generalization of Rogers–Ramanujan combinatorial identities, by constructing bases of vacuum spaces for the principal Heisenberg subalgebra of standard [Formula: see text]-modules, parametrized with partitions satisfying certain difference 2 conditions. In this paper, we define quasi-particles in the principal picture of [Formula: see text] and construct quasi-particle monomial bases of standard [Formula: see text]-modules for which principally specialized characters are given as products of sum sides of the corresponding analytic Rogers–Ramanujan-type identities with the character of the Fock space for the principal Heisenberg subalgebra.
Minimization problems for inhomogeneous Rayleigh quotients
Authors: Bocea Marian , Mihăilescu Mihai
Published: August 2017

In this paper, the minimization problem [Formula: see text] where [Formula: see text] is studied when [Formula: see text] ([Formula: see text]) is an open, bounded, convex domain with smooth boundary and [Formula: see text]. We show that [Formula: see text] is either zero, when the maximum of the distance function to the boundary of [Formula: see text] is greater than [Formula: see text], or it is a positive real number, when the maximum of the distance function to the boundary of [Formula: see text] belongs to the interval [Formula: see text]. In the latter case, we provide estimates for [Formula: see text] and show that for [Formula: see text] sufficiently large [Formula: see text] coincides with the principal frequency of the [Formula: see text]-Laplacian in [Formula: see text]. Some particular cases and related problems are also discussed.
Separable extensions for crossed products over monoidal Hom-Hopf algebras
Authors: Wang Zhongwei , Chen Yuanyuan , Zhang Liangyun
Published: August 2017

Let [Formula: see text] be a Frobenius monoidal Hom-Hopf algebra, and [Formula: see text] an [Formula: see text]-Hom-Hopf Galois extension of [Formula: see text]. We prove that the separability of the Hom-algebra extension [Formula: see text] is equivalent to the existence of a trace one element [Formula: see text] that centralizes [Formula: see text]. As applications, we obtain the differentiated conditions for the extension [Formula: see text] to be separable, and deduce a Doi’s result of Hom-type.
PAcluster: Clustering polyadenylation site data using canonical correlation analysis
Authors: Ji Guoli , Lin Qianmin , Long Yuqi , Ye Congting , Ye Wenbin , Wu Xiaohui
Published: August 2017

Alternative polyadenylation (APA) is a pervasive mechanism that contributes to gene regulation. Increasing sequenced poly(A) sites are placing new demands for the development of computational methods to investigate APA regulation. Cluster analysis is important to identify groups of co-expressed genes. However, clustering of poly(A) sites has not been extensively studied in APA, where most APA studies failed to consider the distribution, abundance, and variation of APA sites in each gene. Here we constructed a two-layer model based on canonical correlation analysis (CCA) to explore the underlying biological mechanisms in APA regulation. The first layer quantifies the general correlation of APA sites across various conditions between each gene and the second layer identifies genes with statistically significant correlation on their APA patterns to infer APA-specific gene clusters. Using hierarchical clustering, we comprehensively compared our method with four other widely used distance measures based on three performance indexes. Results showed that our method significantly enhanced the clustering performance for both synthetic and real poly(A) site data and could generate clusters with more biological meaning. We have implemented the CCA-based method as a publically available R package called PAcluster, which provides an efficient solution to the clustering of large APA-specific biological dataset.
Systematic investigations of gene effects on both topologies and supports: An Echinococcus illustration
Authors: Guyeux Christophe , Chrétien Stéphane , Côté Nathalie M.-L. , Bahi Jacques M.
Published: August 2017

In this paper, we propose a high performance computing toolbox implementing efficient statistical methods for the study of phylogenies. This toolbox, which implements logit models and LASSO-type penalties, gives a way to better understand, measure, and compare the impact of each gene on a global phylogeny. As an application, we study the Echinococcus phylogeny, which is often considered as a particularly difficult example. Mitochondrial and nuclear genomes (19 coding sequences) of nine Echinococcus species are considered in order to investigate the molecular phylogeny of this genus. First, we check that the 19 gene trees lead to 19 totally different unsupported topologies (a topology is the sister relationship when both branch lengths and supports are ignored in a phylogenetic tree), while using the 19 genes as a whole are not sufficient for estimating the phylogeny. In order to circumvent this issue and understand the impact of the genes, we computed 43,796 trees using combinations ranging from 13 to 19 genes. By doing so, 15 topologies are obtained. Four particular topologies, appearing more robust and frequent, are then selected for more precise investigation. Refining further our statistical analysis, a particularly robust topology is extracted. We also carefully demonstrate the influence of nuclear genes on the likelihood of the phylogeny.
Venture Capital and Innovation: Evidence from European Economic Area Countries
Authors: Pradhan Rudra P. , Maradana Rana P. , Zaki Danish B. , Dash Saurav , Jayakumar Manju , Gaurav Kunal
Published: August 2017

The paper examines the long-run relationship between venture capital and innovation in the 19 European Economic Area (EEA) countries over the period 1989–2014. We use three different indicators of venture capital (VC), such as VC at early stage investment, VC at later stage investment, and VC total investment, and seven different indicators of innovation, such as patents-residents, patents-nonresidents, patents-total, research and development expenditure, researchers in research and development activities, high-technology exports, and scientific and technical journal articles, to examine this long-run relationship. Using cointegration technique, the study warrants the support of long-run relationship between venture capital and innovation in few cases, typically with reference to a particular VC indicator and innovation indicator. Expending the Granger causality test, the study finds the presence of both bidirectional and unidirectional causality between venture capital and innovation. However, these results vary from country-to-country within the EEA countries, depending upon the types of VC indicator and innovation indicator that we use in a particular empirical exploration process. The policy implication of this study is that the economic policies should recognize the differences in the venture capital and innovation in order to maintain the sustainable development in these EEA countries.
Effects of Nano-Diamond on Magnetorheological Fluid Properties
Authors: Zhao Mingmei , Zhang Jinqiu , Yao Jun , Peng Zhizhao
Published: August 2017

In order to analyze the effects of nano-diamond on the performance of magnetorheological fluids (MRFs), in this paper, the MRF-1 with a 2% mass fraction in nano-diamond and the MRF-2 without nano-diamond were prepared by the carbonyl iron powder as the dispersed phase and the synthetic mineral oil as the continuous phase. The viscosity and shear stress of MRFs under different magnetic fields were measured by the Anton-Paar rheometer (MCR 302). The MRF settling stability was studied by a standing observation method. A four-ball wear machine was utilized for the wear test at 0.1 T of magnetic field, whereas the magnetic field was provided by an external coil. Also, the three-dimensional white light interferometer was utilized to observe the surface of the ball wear spot, in order to determine the MRF friction properties. The results demonstrated that the nano-diamond had a significant increase in the surface wear. The shear yield strength and settling stability of the MRF could be highly enhanced. The higher the strength of the magnetic field was, the higher the difference in the shear yield strength was. These phenomena demonstrated that the physical properties of the nano-diamond could have a higher impact on MRF, which was of high significance to the preparation of MRFs with excellent performance.