Narrow Results

An important challenge in respiration related studies is to investigate the influence of external stimuli on human respiration. Auditory stimulus is an important type of stimuli that influences human respiration. However, no one discovered any trend, which relates the characteristics of the auditory stimuli to the characteristics of the respiratory signal. In this paper, we investigate the correlation between auditory stimuli and respiratory signal from fractal point of view. We found out that the fractal structure of respiratory signal is correlated with the fractal structure of the applied music. Based on the obtained results, the music with greater fractal dimension will result in respiratory signal with smaller fractal dimension. In order to verify this result, we benefit from approximate entropy. The results show the respiratory signal will have smaller approximate entropy by choosing the music with smaller approximate entropy. The method of analysis could be further investigated to analyze the variations of different physiological time series due to the various types of stimuli when the complexity is the main concern.

Metabolism is one of the best studied fields of biochemistry, but its regulation involves processes on many different levels, some of which are still not understood well enough to allow for quantitative modeling and prediction. Glycolysis in yeast is a good example: although high-quality quantitative data are available, well-established mathematical models typically only cover direct regulation of the involved enzymes by metabolite binding. The effect of various metabolites on the enzyme kinetics is summarized in carefully developed mathematical formulae. However, this approach implicitly assumes that the enzyme concentrations themselves are constant, thus neglecting other regulatory levels – e.g. transcriptional and translational regulation – involved in the regulation of enzyme activities. It is believed, however, that different experimental conditions result in different enzyme activities regulated by the above mechanisms. Detailed modeling of all regulatory levels is still out of reach since some of the necessary data – e.g. quantitative large scale enzyme concentration data sets – are lacking or rare. Nevertheless, a viable approach is to include the regulation of enzyme concentrations into an established model and to investigate whether this improves the predictive capabilities. Proteome data are usually hard to obtain, but levels of mRNA transcripts may be used instead as clues for changes in enzyme concentrations. Here we investigate whether including mRNA data into an established model of yeast glycolysis allows to predict the steady state metabolic concentrations for different experimental conditions. To this end, we modified an established ODE model for the glycolytic pathway of yeast to include changes of enzyme concentrations. Presumable changes were inferred from mRNA transcript level measurement data. We investigate how this approach can be used to predict metabolite concentrations for steady-state yeast cultures at five different oxygen levels ranging from anaerobic to fully aerobic conditions. We were partly able to reproduce the experimental data and present a number of changes that were necessary to improve the modeling result.

ScinoPharm Taiwan and Coland Holdings establish strategic alliance for oncological injectable products for China.

Researchers investigate the effects of thinning on soil respiration and its sensitivity in a pine plantation, eastern Tibetan Plateau.

Ascletis gains China market rights from Janssen to a clinical stage HIV protease inhibitor.

The genome sequences of soft-shell turtle and green sea turtle offer new clues to the development and evolution of turtle-specific body plan.

Daiichi Sankyo launches Silodosin for the treatment of Dysuria in China.

China plans research centres to aid developing world.

HKU finds novel coronavirus can infect humans respiratory tract even better than SARS-CoV.

BGI Health collaborates with Eastern Biotech & Life Sciences on non-invasive fetal Trisomy test for improving reproductive health in the Middle East.

Baxter China partners with government to increase access to renal therapy.

Motivation: Living systems have a complex hierarchical organization that can be viewed as a set of dynamically interacting subsystems. Thus, to simulate the internal nature and dynamics of the entire biological system, we should use the iterative way for a model reconstruction, which is a consistent composition and combination of its elementary subsystems. In accordance with this bottom-up approach, we have developed the MAthematical Models of bioMOlecular sysTems (MAMMOTh) tool that consists of the database containing manually curated MAMMOTh fitted to the experimental data and a software tool that provides their further integration.

Results: The MAMMOTh database entries are organized as building blocks in a way that the model parts can be used in different combinations to describe systems with higher organizational level (metabolic pathways and/or transcription regulatory networks). The tool supports export of a single model or their combinations in SBML or Mathematica standards. The database currently contains 110 mathematical sub-models for Escherichia coli elementary subsystems (enzymatic reactions and gene expression regulatory processes) that can be combined in at least 5100 complex/sophisticated models concerning more complex biological processes as de novo nucleotide biosynthesis, aerobic/anaerobic respiration and nitrate/nitrite utilization in E. coli. All models are functionally interconnected and sufficiently complement public model resources.

Availability: http://mammoth.biomodelsgroup.ru

To investigate whether the first intrinsic mode function, obtained from Hilbert–Huang transform (HHT), of heart rate variability is respiratory related. Electrocardiogram and chest circumference signals were recorded from 10 healthy subjects at supine rest. The HHT was applied to both R-R interval and chest circumference signals to figure out their first intrinsic mode functions (C1_RR and C1_RESP, respectively) from which the instantaneous amplitude, phase, and frequency were calculated. Although the instantaneous amplitudes and frequencies of C1_RR and C1_RESP were variable, linear regression analysis indicated a phase lock between C1_RR and C1_RESP. Intake of 500 ml water significantly elevated the amplitude ratio of C1_RR to C1_RESP; however, the phase difference of C1_RR to C1_RESP was still unchanged. The data indicate that the first intrinsic mode function of heart rate variability is respiratory related and may be equivalent to respiratory sinus arrhythmia. As compared to fast Fourier transform, HHT of respiratory sinus arrhythmia provides a comparative spatial measurement with a much higher temporal resolution.

The following sections are included:

• Summary

• Introduction

• Opportunities for Mitochondrial Therapeutics

• Acknowledgments

• References