Analysis of fetal heart rate asymmetry before and after 35 weeks of gestation

In this study, we have investigated the evidence of fetal heart rate asymmetry and how the fetal heart rate asymmetry changes before and after 35 weeks of gestation. Noninvasive fetal electrocardiogram (fECG) signals from 45 pregnant women at the gestational age from16 to 41 weeks with normal single pregnancies were analysed. A nonlinear parameter called heart rate asymmetry (HRA) index that measures time asymmetry of RR interval time-series signal was used to understand the changes of HRA in early and late fetus groups. Results indicate that fetal HRA measured by Porta's Index (PI) consistently increases after 35 weeks gestation compared to foetus before 32 weeks of gestation. It might be due to significant changes of sympatho-vagal balance towards delivery with more sympathetic surge. On the other hand, Guzik's Index (GI) showed a mixed effect i.e., increases at lower lags and decreases at higher lags. Finally, fHRA could potentially help identify normal and the pathological autonomic nervous system development.

Functional genomic analysis of systemic cell division regulation in legumes

Legumes develop root nodules from pluripotent stem cells in the rootpericycle in response to mitogenic activation by a decorated chitin-likenodulation factor synthesized in Rhizobium bacteria. The soybean genes encoding the receptor for such signals were cloned using map-based cloning approaches. Pluripotent cells in the root pericycle and the outer or inner cortex undergo repeated cell divisions to initiate a composite nodule primordium that develops to a functional nitrogen-fixing nodule. The process itself is autoregulated, leading to the characteristic nodulation of the upper root system. Autoregulation of nodulation (AON) in all legumes is controlled in part by a leucine-rich repeat receptor kinase gene (GmNARK). Mutations of GmNARK, and its other legume orthologues, result in abundant nodulation caused by the loss of a yet-undefined negative nodulation repressor system. AON receptor kinases are involved in perception of a long distance, root-derived signal, to negatively control nodule proliferation. GmNARK and LjHAR1 are expressed in phloem parenchyma. GmNARK kinase domain interacts with Kinase Associated Protein Phosphatase (KAPP). NARK gene expression did not mirror biological NARK activity in nodulation control, as q-RT-PCR in soybean revealed high NARK expression in roots, root tips, leaves, petioles, stems and hypocotyls, while shoot and root apical meristems were devoid of NARK RNA. High through-put transcript analysis in soybean leaf and root indicated that major genes involved in JA synthesis or response are preferentially down-regulated in leaf but not root of wild type, but not NARK mutants, suggesting that AON signaling may in part be controlled by events relating to hormone metabolism. Ethylene and abscisic acid insensitive mutants of L. japonicus are described. Nodulation in legumes has significance to global economies and ecologies, as the nitrogen input into the biosphere allows food, feed and biofuel production without the inherent costs associated with nitrogen fertilization [1]. Nodulation involves the production of a new organ capable of nitrogen fixation [2] and as such is an excellent system to study plant – microbe interaction, plant development, long distance signaling and functional genomics of stem cell proliferation [3, 4]. Concerted international effort over the last 20 years, using a combination of induced mutagenesis followed by gene discovery (forward genetics), and molecular/biochemical approaches revealed a complex developmental pathway that ‘loans’ genetic programs from various sources and orchestrates these into a novel contribution. We report our laboratory’s contribution to the present analysis in the field.

Surface enhanced Raman scattering (SERS) fabrics for trace analysis

Flexible SERS active substrates were prepared by modification of silk fabrics with gold nanoparticles. Gold nanoparticles were in-situ synthesized after heating the silk fabrics immersed in gold ion solution. Localized surface plasmon resonance (LSPR) properties of the treated silk fabrics varied as the concentration of gold ions changed, in relation to the morphologies of gold nanoparticles on silk. In addition, X-ray diffraction (XRD) was used to observe the structure of the gold nanoparticle treated silk fabrics. The SERS enhancement effect of the silk fabrics treated with gold nanoparticles was evaluated by collecting Raman signals of different concentrations of p-aminothiophenol (PATP), 4-mercaptopyridine (4-MPy) and crystal violet (CV) solutions. The results demonstrate that the silk fabrics corresponding to 0.3 and 0.4 mM of gold ions possess high SERS activity compared to the other treated fabrics. It is suggested that both the gold content and morphologies of gold nanoparticles dominate the SERS effect of the treated silk fabrics.

Robust time-spread echo watermarking using characteristics of host signals

A robust audio watermarking method based on the time-spread (TS) echo hiding scheme is proposed. Compared with existing TS watermarking methods, the approach is more robust as it exploits the characteristics of host signals in the encoding stage. Theoretical analysis and simulation examples demonstrate the effectiveness and advantages of the method.

Understanding ageing effects using complexity analysis of foot-ground clearance during walking

Ageing influences gait patterns which in turn can affect the balance control of human locomotion. Entropy-based regularity and complexity measures have been highly effective in analysing a broad range of physiological signals. Minimum toe clearance (MTC) is an event during the swing phase of the gait cycle and is highly sensitive to the spatial balance control properties of the locomotor system. The aim of this research was to investigate the regularity and complexity of the MTC time series due to healthy ageing and locomotors' disorders. MTC data from 30 healthy young (HY), 27 healthy elderly (HE) and 10 falls risk (FR) elderly subjects with balance problems were analysed. Continuous MTC data were collected and using the first 500 data points, MTC mean, standard deviation (SD) and entropy-based complexity analysis were performed using sample entropy (SampEn) for different window lengths (m) and filtering levels (r). The MTC SampEn values were lower in the FR group compared to the HY and HE groups for all m and r. The HY group had a greater mean SampEn value than both HE and FR reflecting higher complexity in their MTC series. The mean SampEn values of HY and FR groups were found significantly different for m = 2, 4, 5 and r = (0.1-0.9) × SD, (0.3-0.9) × SD and (0.3-0.9) × SD, respectively. They were also significant difference between HE and FR groups for m = 4-5 and r = (0.3-0.7) × SD, but no significant differences were seen between HY and HE groups for any m and r. A significant correlation of SampEn with SD of MTC was revealed for the HY and HE groups only, suggesting that locomotor disorders could significantly change the regularity or the complexity of the MTC series while healthy ageing does not. These results can be usefully applied to the early diagnosis of common gait pathologies.