Spurious detection of phase synchronization in coupled nonlinear oscillators

Coupled nonlinear systems under certain conditions exhibit phase synchronization, which may change for different frequency bands or with presence of additive system noise. In both cases, Fourier filtering is traditionally used to preprocess data. We investigate to what extent the phase synchronization of two coupled R\"{o}ssler oscillators depends on (1) the broadness of their power spectrum, (2) the width of the band-pass filter, and (3) the level of added noise. We find that for identical coupling strengths, oscillators with broader power spectra exhibit weaker synchronization. Further, we find that within a broad band width range, band-pass filtering reduces the effect of noise but can lead to a spurious increase in the degree of synchronization with narrowing band width, even when the coupling between the two oscillators remains the same.Comment: 4 pages,6 figure

The Effect of Work Environment, Motivation, and Leadership on Employee Performance with Employee Engagement as Mediating Variable

Performance appraisal is a major factor in company development, so companies can assess the level of achievement of the vision and mission, business performance appraisal, manager appraisal, cross-departmental assessment, and assessment of all employees in the company. This assessment is intended to predict the company's future expectations. The purpose of this study is to analyze and determine which factors affect employee performance in the workplace. This research is conducted at one of the construction services companies where the number of skilled employees continues to decrease, and the company has experienced a decline in achievement of Key Performance Indicators (KPI) from 2015 to 2018. The analysis technique used in this study uses the Structural Equation Modeling method. (SEM) with the help of SmartPLS (Partial Least Square) software. The results of the analysis show that the work environment variable (X1) has a positive and significant relationship to the employee engagement variable (Y1) and has a positive but not significant effect on the Employee Performance variable (Y2), the motivation variable (X2) has a positive and a significant influence on the employee engagement variable (Y1) and employee performance (Y2). The leadership variable (X3) has a positive but not significant effect on the employee engagement variable (Y1) and has a positive but not significant effect on the employee performance variable (Y2). The employee engagement variable (Y1) as a mediating variable has a positive and significant effect on the employee performance variable (Y2). The results also show that the employee engagement variable has a simultaneous influence of 56.8% which can be explained by the variables of work environment, motivation, and leadership. Employee performance variables have a simultaneous effect of 60.5% which can be explained by the variables of work environment, motivation, leadership, and employee engagement

Effectiveness of hydropathic compress of dandelion in ameliorating complications of arteriovenous fistula

Purpose: To investigate the effect of dandelion hydropathic compress on the complications of autologous arteriovenous fistula (AVF).Methods: From January to June 2019, a total of 162 patients treated with arteriovenous fistula for hemodialysis in the blood purification department of Affiliated Hospital of Jining Medical University were enrolled. They were randomly assigned at a ratio of 1:1 to receive either conventional infrared irradiation (control group) or conventional irradiation plus dandelion hydropathic compress (study group). The clinical endpoint was the amelioration of the complications of arteriovenous fistula after 6 months of treatment.Results: Dandelion hydropathic compress combined with conventional infrared irradiation was associated with a significantly higher clinical efficacy (96.30 %) than conventional infrared irradiation alone (77.78 %). The application of dandelion hydropathic compress plus infrared irradiation resulted in significantly reduced pain, a better quality of life, and a lower incidence of complications (p < 0.05).Conclusion: Dandelion hydropathic compress plus routine nursing and infrared irradiation lower the incidence of complications, improve blood flow, relieve pain, and enhance the quality of life of patients. Further clinical trials are needed to confirm the usefulness of this therapeutic strategy

Using cell fate attractors to uncover transcriptional regulation of HL60 neutrophil differentiation

<p>Abstract</p> <p>Background</p> <p>The process of cellular differentiation is governed by complex dynamical biomolecular networks consisting of a multitude of genes and their products acting in concert to determine a particular cell fate. Thus, a systems level view is necessary for understanding how a cell coordinates this process and for developing effective therapeutic strategies to treat diseases, such as cancer, in which differentiation plays a significant role. Theoretical considerations and recent experimental evidence support the view that cell fates are high dimensional attractor states of the underlying molecular networks. The temporal behavior of the network states progressing toward different cell fate attractors has the potential to elucidate the underlying molecular mechanisms governing differentiation.</p> <p>Results</p> <p>Using the HL60 multipotent promyelocytic leukemia cell line, we performed experiments that ultimately led to two different cell fate attractors by two treatments of varying dosage and duration of the differentiation agent all-trans-retinoic acid (ATRA). The dosage and duration combinations of the two treatments were chosen by means of flow cytometric measurements of CD11b, a well-known early differentiation marker, such that they generated two intermediate populations that were poised at the apparently same stage of differentiation. However, the population of one treatment proceeded toward the terminally differentiated neutrophil attractor while that of the other treatment reverted back toward the undifferentiated promyelocytic attractor. We monitored the gene expression changes in the two populations after their respective treatments over a period of five days and identified a set of genes that diverged in their expression, a subset of which promotes neutrophil differentiation while the other represses cell cycle progression. By employing promoter based transcription factor binding site analysis, we found enrichment in the set of divergent genes, of transcription factors functionally linked to tumor progression, cell cycle, and development.</p> <p>Conclusion</p> <p>Since many of the transcription factors identified by this approach are also known to be implicated in hematopoietic differentiation and leukemia, this study points to the utility of incorporating a dynamical systems level view into a computational analysis framework for elucidating transcriptional mechanisms regulating differentiation.</p

In Situ Absorption in Rat Intestinal Tract of Solid Dispersion of Annonaceous Acetogenins

Isolated from Annona squamosa L, Annonaceous acetogenins (ACGs) exhibit a broad range of biological properties yet absorbed badly due to the low solubility. Solid dispersion in polyethylene glycol 4000 (PEG 4000) has been developed to increase the solubility and oral absorption of ACGs. The formulation of ACGS-solid dispersion was optimized by a simplex lattice experiment design and carried out by a solvent-fusion method. We studied the absorption property of ACGs in rat's intestine, which showed there was a good absorption and uptake percentages with solid dispersion. The study on uptake percentage in different regions of rat's intestine attested that the duodenum had the best permeability, followed by jejunum, ileum, and colon in order with no significant differences. So the paper drew the conclusion that solid dispersion could improve the solubility and oral absorption of annonaceous acetogenins

Effects and Mechanisms of Surface Topography on the Antiwear Properties of Molluscan Shells ( Scapharca subcrenata

The surface topography (surface morphology and structure) of the left Scapharca subcrenata shell differs from that of its right shell. This phenomenon is closely related to antiwear capabilities. The objective of this study is to investigate the effects and mechanisms of surface topography on the antiwear properties of Scapharca subcrenata shells. Two models are constructed—a rib morphology model (RMM) and a coupled structure model (CSM)—to mimic the topographies of the right and left shells. The antiwear performance and mechanisms of the two models are studied using the fluid-solid interaction (FSI) method. The simulation results show that the antiwear capabilities of the CSM are superior to those of the RMM. The CSM is also more conducive to decreasing the impact velocity and energy of abrasive particles, reducing the probability of microcrack generation, extension, and desquamation. It can be deduced that in the real-world environment, Scapharca subcrenata’s left shell sustains more friction than its right shell. Thus, the coupled structure of the left shell is the result of extensive evolution

Improving signal intensities for genes with low-expression on oligonucleotide microarrays

BACKGROUND: DNA microarrays using long oligonucleotide probes are widely used to evaluate gene expression in biological samples. These oligonucleotides are pre-synthesized and sequence-optimized to represent specific genes with minimal cross-hybridization to homologous genes. Probe length and concentration are critical factors for signal sensitivity, particularly when genes with various expression levels are being tested. We evaluated the effects of oligonucleotide probe length and concentration on signal intensity measurements of the expression levels of genes in a target sample. RESULTS: Selected genes of various expression levels in a single cell line were hybridized to oligonucleotide arrays of four lengths and four concentrations of probes to determine how these critical parameters affected the intensity of the signal representing their expression. We found that oligonucleotides of longer length significantly increased the signals of genes with low-expression in the target. High-expressing gene signals were also boosted but to a lesser degree. Increasing the probe concentration, however, did not linearly increase the signal intensity for either low- or high-expressing genes. CONCLUSIONS: We conclude that the longer the oligonuclotide probe the better the signal intensities of low expressing genes on oligonucleotide arrays

Obtaining reliable information from minute amounts of RNA using cDNA microarrays

BACKGROUND: High density cDNA microarray technology provides a powerful tool to survey the activity of thousands of genes in normal and diseased cells, which helps us both to understand the molecular basis of the disease and to identify potential targets for therapeutic intervention. The promise of this technology has been hampered by the large amount of biological material required for the experiments (more than 50 μg of total RNA per array). We have modified an amplification procedure that requires only 1 μg of total RNA. Analyses of the results showed that most genes that were detected as expressed or differentially expressed using the regular protocol were also detected using the amplification protocol. In addition, many genes that were undetected or weakly detected using the regular protocol were clearly detected using the amplification protocol. We have carried out a series of confirmation studies by northern blotting, western blotting, and immunohistochemistry assays. RESULTS: Our results showed that most of the new information revealed by the amplification protocol represents real gene activity in the cells. CONCLUSION: We have confirmed a powerful and consistent cDNA microarray procedure that can be used to study minute amounts of biological tissue