Differences in Gait Stability and Acceleration Characteristics Between Healthy Young and Older Females

Our aim was to evaluate differences in gait acceleration intensity, variability, and stability of feet and trunk between older females (OF) and young females (YF) using inertial sensors. Twenty OF (mean age 68.4, SD 4.1 years) and 18 YF (mean age 22.3, SD 1.7 years) were asked to walk straight for 100 meters at their preferred speed, while wearing inertial sensors on their heels and lower back. We calculated spatiotemporal measures, foot and trunk acceleration characteristics, their variability, and trunk stability using the local divergence exponent (LDE). Two-way ANOVA (such as the factors foot and age), Student's t-test and Mann–Whitney U test were used to compare statistical differences of measures between groups. Cohen's d effects were calculated for each variable. Foot maximum vertical (VT) acceleration and amplitude, trunk-foot VT acceleration attenuation, and their variability were significantly smaller in OF than in YF. In contrast, trunk mediolateral (ML) acceleration amplitude, maximum VT acceleration, amplitude, and their variability were significantly larger in OF than in YF. Moreover, OF showed lower stability (i.e., higher LDE values) in ML acceleration, ML, and VT angular velocity of the trunk. Even though we measured healthy OF, these participants showed lower VT foot accelerations with higher VT trunk acceleration, lower trunk-foot VT acceleration attenuation, less gait stability, and more variability of the trunk, and hence, were more likely to fall. These findings suggest that instrumented gait measurements may help for early detection of changes or impairments in gait performance, even before this can be observed by clinical eye or gait speed.

Danhong Injection and Trimetazidine Protect Cardiomyocytes and Enhance Calcium Handling after Myocardial Infarction

Myocardial infarction (MI) is one of the leading causes of death worldwide. However, there is no effective treatment for MI. In this study, trimetazidine (TMZ) and Danhong injection (DHI), representing western medicine and traditional Chinese medicine for MI, were used as tools to identify vital processes in alleviating MI injury. Administration of DHI and TMZ obviously decreased myocardial infarct size, improved ultrasonic heart function, and reduced creatine kinase (CK), lactate dehydrogenase (LDH), and glutamic oxaloacetic transaminase (AST) levels after MI. RNA-seq results indicated calcium ion handling and negative regulation of apoptotic process were vital processes and DHI and TMZ obviously reduced the expression of CaMK II and inhibited cleaved caspase-3 and Bax. Furthermore, DHI and TMZ increased p-S16-PLB, p-S16T17-PLB, CACNA1C, p-RyR2, and p-PKA expression but did not affect SERCA2a expression. In addition to the enhancement of cardiac myocyte shortening amplitude, maximum shortening velocity, and calcium transients, DHI and TMZ increased sarcoplasmic reticulum calcium content and enhanced SERCA2a calcium uptake capability by upregulating the phosphorylation of PLB but did not affect calcium exclusion by NCX. In conclusion, DHI and TMZ protect against MI through inhibiting apoptosis by downregulating CaMKII pathway and enhancing cardiac myocyte contractile functions possibly through the PKA signaling pathway.

A Method to Obtain Parameters of One-Column Jansen–Rit Model Using Genetic Algorithm and Spectral Characteristics

In this paper, a method of obtaining parameters of one-column Jansen–Rit model was proposed. Methods present in literature are focused on obtaining parameters in an on-line manner, producing a set of parameters for every point in time. The method described in this paper can provide one set of parameters for a whole, arbitrarily long signal. The procedure consists of obtaining specific frequency features, then minimizing mean square error of those features between the measured signal and the modeled signal, using genetic algorithm. This method produces an 8-element vector, which can be treated as an EEG signal feature vector specific for a person. The parameters which were being obtained are maximum postsynaptic potential amplitude, maximum inhibitory potential amplitude, ratio of the number of connections between particular neuron populations, the shape of a nonlinear function transforming the average membrane potential into the firing rate and the input noise range. The method shows high reproducibility (intraclass correlation coefficient for particular parameters ranging from 0.676 to 0.978) and accuracy (ranging from 0.662 to 0.863). It was additionally verified using EEG signal obtained for a single participant. This signal was measured using Emotiv EPOC+ NeuroHeadset.

Short-Time Fourier Transform Using Odd Symmetric Window Function

In this paper, a novel time-frequency (TF) analysis method, called the short-time Fourier transform using odd symmetric window function (OSTFT), is proposed by using odd symmetric window function to replace the conventional even window function of STFT. Different from conventional STFT acquiring the amplitude maximum at time and frequency centers, OSTFT acquires the minimum amplitude of 0. Hence, OSTFT can obtain a TFR with high TF resolution by utilizing the leaked energy rather than restraining it. It is worth to mention that the proposed OSTFT can vitiate the effect of window size we choose on the TFR obtained. Furthermore, it also has a good performance on signals with complex instantaneous frequencies (IF), even crossing IFs. Because we just replace the conventional window function of STFT, the time-consuming of the proposed OSTFT is at the same level as the conventional STFT. The effectiveness of proposed OSTFT has been validated on two complex multi-component simulated numerical signals and a signal collected from the brown bat.

Application of Seismuc Attribute Analysis to Reserch the Distribution of Middle Miocene Coral Reef Carbonate in Block 04-3, Nam Con Son Basin

The seismic properties of Root Mean Square Amplitude, Maximum Amplitude, and Sum of Positive Amplitude most clearly reflect the distribution characteristics of middle Miocene carbonate sediments in ​​block 04-3, Nam Con Son basin. Middle Miocene carbonate is commonly distributed on both reflection surfaces of P1 and P2. Within each reflective surface, carbonate sediments are concentrated around the uplifting zones, such as structures of Thien Ung - Mang Cau, Dai Hung and Bo Cau. These are completely consistent with the results of the interpretation of well-log data of Vietsovpetro, VSP [1]. The wells C-2X and C-4X located at the edge of the uplifting zone should have the thickest carbonates. According to the results of amplitude attribute analysis, these wells are distributed in the high concentration area of carbonate formations. Meanwhile well C-1X and well C-3X, which are near the top of the uplifting zone and further away from the uplifting structure have thin carbonate set and belongs to a low carbonate density area.

Experimental investigation of energy harvesting eel in the wake of bluff body under ocean waves

Investigation of the energy harvesting from deep water waves by using flexible piezoelectric eel in a controlled environment is studied. Energy harvesting potential is examined as a function of streamwise distance from the fixed cylinder and spanwise gap along with the cylinder at different wave conditions. Output voltage and eel flapping behavior are dependent on cylinder vortices caused by local wavelength and wave amplitude. Maximum energy is harvested when the eel is placed near to the surface caused by high flapping amplitude and frequency. Similarly, at greater depth low flapping amplitude is observed resulting in small output voltage. Maximum output voltages are found at the shorter wavelength and at a streamwise distance of gx = 1.25 (where gx is the ratio of spacing “S” between cylinder and eel to the diameter of cylinder “D”) for all spanwise gaps along with the cylinder and minimum voltages are calculated at a longer wavelength and streamwise distance gx = 0.75. An increase of 65% in energy harvesting is observed by switching longer wavelengths (λ) to a shorter one and changing the piezo-eel spanwise gap from deep to the shallow depth. Whereas, an increase of 31.5% was found by keeping wavelength constant and changing the spanwise gap of eel. Furthermore, it is observed that energy harvesting from the wake of a bluff body in the wavy motion of water is sensitive to the wavelength and wave height.

Representation of the equatorial stratopause semiannual oscillation in global atmospheric reanalyses

This paper reports on a project to compare the representation of the semiannual oscillation (SAO) in the equatorial stratosphere and lower mesosphere within six major global atmospheric reanalysis datasets and with recent satellite Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) and Microwave Limb Sounder (MLS) observations. All reanalyses have a good representation of the quasi-biennial oscillation (QBO) in the equatorial lower and middle stratosphere and each displays a clear SAO centered near the stratopause. However, the differences among reanalyses are much more substantial in the SAO region than in the QBO-dominated region. The degree of disagreement among the reanalyses is characterized by the standard deviation (SD) of the monthly mean zonal wind and temperature; this depends on latitude, longitude, height, and time. The zonal wind SD displays a prominent equatorial maximum that increases with height, while the temperature SD reaches a minimum near the Equator and is largest in the polar regions. Along the Equator, the zonal wind SD is smallest around the longitude of Singapore, where consistently high-quality near-equatorial radiosonde observations are available. Interestingly, the near-Singapore minimum in SD is evident to at least ∼3 hPa, i.e., considerably higher than the usual ∼10 hPa ceiling for in situ radiosonde observations. Our measurement of the agreement among the reanalyses shows systematic improvement over the period considered (1980–2016), up to near the stratopause. Characteristics of the SAO at 1 hPa, such as its detailed time variation and the displacement off the Equator of the zonal wind SAO amplitude maximum, differ significantly among the reanalyses. Disagreement among the reanalyses becomes still greater above 1 hPa. One of the reanalyses in our study also has a version produced without assimilating satellite observations, and a comparison of the SAO in these two versions demonstrates the very great importance of satellite-derived temperatures in the realistic analysis of the tropical upper stratospheric circulation.

Representation of the Equatorial Stratopause Semiannual Oscillation in Global Atmospheric Reanalyses

This paper reports on a project to compare the representation of the semiannual oscillation (SAO) in the equatorial stratosphere and lower mesosphere among six major global atmospheric reanalysis datasets and with recent satellite SABER and MLS observations. All reanalyses have a good representation of the quasi-biennial oscillation (QBO) in the equatorial lower and middle stratosphere and each displays a clear SAO centered near the stratopause. However, the differences among reanalyses are much more substantial in the SAO region than in the QBO dominated region. The degree of disagreement among the reanalyses is characterized by the standard deviation (SD) of the monthly-mean zonal wind and temperature; this depends on latitude, longitude, height, and time. The zonal wind SD displays a prominent equatorial maximum that increases with height, while the temperature SD is minimum near the equator and largest in the polar regions. Along the equator the zonal wind SD is smallest around the longitude of Singapore where consistently high-quality near-equatorial radiosonde observations are available. Interestingly the near-Singapore minimum in SD is evident to at least ~ 3 hPa, i.e. considerably higher than the usual ~ 10 hPa ceiling for in situ radiosonde observations. Our measurement of the agreement among the reanalyses shows systematic improvement over the period considered (1980–2016), up to near the stratopause. Characteristics of the SAO at 1 hPa, such as its detailed time variation and the displacement off the equator of the zonal wind SAO amplitude maximum, differ significantly among the reanalyses. Disagreement among the reanalyses becomes still greater above 1 hPa. One of the reanalyses in our study also has a version produced without assimilating satellite observations and a comparison of the SAO in these two versions demonstrates the very great importance of satellite derived temperatures in the realistic analysis of the tropical upper stratospheric circulation.

Comparative Analysis of Acoustic Propagation Parameters of Natural Sounds ofAnopheles gambiae s.sandOdorrana tormotaSignificant in Mosquito Startle

Acoustics of varied frequency ranges generated naturally by animals or artificially by electronic devices have shown startle effect to insects. It has been shown that mosquitoes use the reactive near-field in antennae communication with negative phonotaxis in maleAedes diantaeusevoked by low frequency acoustic signals of a carrier frequency 140–200 Hz. Also, studies with the 35-60 kHzOdorrana tormotasound recorded a 46 % repellence in femaleAnopheles gambiae, the malaria vectors. Declining malaria morbidity and mortality is attributed to current vector and pathogen interventions. However, the rate of decline in malaria morbidity and mortality is impeded by buildup of resistance in pathogens and vectors to chemicals. This study therefore characterised animal sounds essential for further investigation in the control of malaria through mosquito startle. The research determined, analysed and compared the acoustic propagation parameters of the recorded natural sounds of the maleAnopheles gambiae, femaleAnopheles gambiaeandOdorrana tormotausing Avisoft SASLAB Pro and Raven Pro 1.5. All sounds were observed to have frequency modulation with harmonics stretching to ultrasonic levels. Uniquesly, the sound ofO. tormotashowed constant frequency modulation. The pupae ofA. gambiaewere reared in vials quarter filled with water and covered with a net at 60-80 % humidity, 25±2 °C temperature and equal light-darkness hour cycle at Kenya Medical Research Institute (KEMRI) entomology laboratories. The parameters showed a significant deference in fundamental frequency (maximum entire), Peak amplitude (maximum), peak amplitude (mean), Peak amplitude (mean entire) and peak amplitude (maximum entire) of the sound of maleA. gambiaeandO. tormota(p < 0.05). The maximum frequency (minimum entire) of both sexes ofA. gambiaewas equal (1.90 kHz) with variability being observed in maximum frequency (end), maximum frequency (maximum), maximum frequency (mean), maximum frequency (maximum entire) and maximum frequency (mean entire). Frequency (maximum). A paired samples t-test comparison of the maximum frequency (mean), maximum frequency (maximum), maximum frequency (end), maximum frequency (maximum entire) and maximum frequency (mean entire) of the sound of the femaleA. gambiaeand maleA. gambiaeindicated no significant difference between the sounds (p > 0.05). The maximum frequency (mean) of the sounds of both sexes ofA. gambiaecorrelated highly negative (r = −0.658). The bandwidth (end), bandwidth (maximum), bandwidth (maximum entire), peak amplitude (mean) and bandwidth (mean entire) of the sound of the male compared with femaleA. gambiaediffered significantly. The signal power for the non-pulsate sounds of the maleA. gambiaeremained almost constant at 80 dB from 10 kHz to 65 kHz beyond which the acoustic energy declining to 45 dB. Also, the sounds of the femaleA. gambiaedid not exhibit any spikes in power but remained steady at 85 dB from 10 kHz up to 60 kHz beyond which the acoustic energy declined to 50 dB. The signal power of the pulsate sound ofO. tormotawas 89 dB. The propagation parameters of the male mosquito and O. tormota compared favourably indicating its potential in the startle of the female mosquito.The author summaryPhilip Amuyunzu Mang’are is a PhD. Physics student in Egerton University. He has authored many papers and books. He is currently a Lecturer of Physics (Electronics), Masinde Muliro University of Science and Technology. He is a member of the Biophysical Society and the current President of Biophysical society (Kenya). Prof. Ndiritu F. Gichuki, is a Professor of Physics Egerton University. Currently he is the Registrar Academic Affairs in Chuka University. His vast experience has seen him supervise many postgraduate students who have taken key positions in the society. Prof. Samwel Rotich is a Profesor of Physics in Moi University specialising in Electronics. He has a wide experience in Physics and Biophysics. He is a registered member of the Biophysical Society and the Patron of Biophysical Society Kenya Chapter. He has published many papers and supervised many postgraduate students. Dr. Makatiani Kubochi is a Lecturer in Moi University with vast experience in entomology. She has published many papers and supervised many postgraduate students. Dr. Rapando Bernard Wakhu is a renown theoretical Physicist with experience in acoustics and Fourier analysis based in Masinde Muliro University of Science and Technology. He has supervised many postgraduate students and published many papers.

Application of 3D Seismic Attribute Analyses for Hydrocarbon Prospectivity in Uzot-Field, Onshore Niger Delta Basin, Nigeria

3D seismic interpretative study was carried out across the Uzot-field in the western Coastal Swamp Depobelt of the onshore Niger Delta Basin, Nigeria, with the aim to identify possible hydrocarbon leads and prospects away from the drilled zone, utilizing seismic amplitude attributes. The method employed in this study involved systematic picking of faults and mapping of horizons/reservoir tops across seismic volume and extraction of seismic attributes. Structural analysis indicates the presence of down-to-basin footwall and hanging wall faults associated with rollover anticlines and horst-block (back-to-back fault). Generated time and depth structural maps from three reservoir intervals (D3100, D5000, and D9000) revealed the presence of fault dependent closure across the field. Analyses of relevant seismic attributes such as root-mean-square (RMS) amplitude, maximum amplitude, average energy amplitude, average magnitude amplitude, maximum magnitude attribute, and standard deviation amplitude, which were applied on reservoir tops, revealed sections with bright spot anomalies. These amplitude anomalies served as direct hydrocarbon indicators (DHIs), unravelling the presence and possible hydrocarbon prospective zones. In addition, structural top maps show that booming amplitude is seen within the vicinity of fault closures, an indication that these hydrocarbon prospects are structurally controlled. Results from this study have shown that, away from currently producing zone at the central part of the field, additional leads and prospects exist, which could be further evaluated for hydrocarbon production.