Seismic response and prediction of Ordovician fractured vuggy carbonate reservoirs in the Tazhong Shunnan well A block

2017 ◽  
Vol 5 (1) ◽  
pp. SB45-SB55 ◽  
Author(s):  
Li Zhou ◽  
Hanming Gu ◽  
Lingwei Ma ◽  
Jiao Xue ◽  
Zongjie Li
Keyword(s):  
High Frequency ◽  
Seismic Reflection ◽  
Random Medium ◽  
Low Frequency ◽  
Fault Zones ◽  
Carbonate Reservoirs ◽  
Medium Theory ◽  
Significant Difference ◽  
Seismic Reflections ◽  
Reflection Characteristics

Ordovician fractured vuggy carbonate reservoirs, which are deeply buried in the Tazhong Shunnan area in China, are characterized by high heterogeneity. Meanwhile, there is no significant difference between the geophysical characteristics of the reservoirs and that of the surrounding rocks. We have introduced the multiscale stack random medium theory and built some theoretical seismic-geologic models for the fractured vuggy carbonate reservoirs. Furthermore, we obtained the seismic reflection characteristics corresponding to these models using finite-difference forward modeling. The small random vugs are characterized by weak and chaotic reflections with high frequency, and the large vugs are characterized by strong and chaotic reflections with low frequency. The amplitude of the seismic reflections increases with the increasing vug density, and it decreases with the increasing roughness factor. Combining the synthetic reflection characteristics corresponding to the fractured vuggy carbonate reservoirs and the actual seismic reflections from the drilled reservoirs, we summarized the recognition patterns of the carbonate reservoirs. The predicted results found that the potential fractured vuggy reservoirs at the top of Yijianfang Formation are located in the southwest and northeast, in the vicinity of fault zones. The reservoirs in Peng-Laiba Formation are distributed in the northwest of the block.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

scholarly journals Can a simple, short-term memory task help to screen dyslexia?

2019 ◽  
Author(s):  
Nick Perham ◽  
Toni Howell ◽  
Andy Watt
Keyword(s):  
High Frequency ◽  
Short Term Memory ◽  
Memory Task ◽  
Compulsory Education ◽  
Low Frequency ◽  
Short Term ◽  
Term Order ◽  
Significant Difference ◽  
Support Students

AbstractFunding to support students with dyslexia in post-compulsory education is under pressure and more efficient assessments may offset some of this shortfall. We tested potential tasks for screening dyslexia: recall of adjective-noun, compared to noun-adjective, pairings (syntax) and recall of high versus low frequency letter pairings (bigrams). Students who reported themselves as dyslexic failed to show a normal syntax effect (greater recall of adjective-noun compared to noun-adjective pairings) and no significant difference in recall between the two types of bigrams whereas students who were not dyslexic showed the syntax effect and a bias towards recalling high frequency bigrams. Findings are consistent with recent explanations of dyslexia suggesting that those affected find it difficult to learn and utilise sequential long-term order information (Szmalec et al. Journal of Experimental Psychology: Learning, Memory & Cognition, 37(5) ,1270-1279, 2011). Further, ROC curve analyses revealed both tasks showed acceptable diagnostic properties as they were able to discriminate between the two groups of participants.

Heart rate variability and dissociation in panic disorder

2011 ◽  
Vol 26 (S2) ◽  
pp. 147-147
Author(s):  
T. Diveky ◽  
D. Kamaradova ◽  
A. Grambal ◽  
K. Latalova ◽  
J. Prasko ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Panic Disorder ◽  
Frequency Band ◽  
High Frequency ◽  
Power Spectra ◽  
Low Frequency ◽  
Very Low Frequency ◽  
Significant Difference ◽  
Before And After

The aim of our study is to measure very low frequency band (VLF), low frequency band (LF) and high frequency band (HF) components of R-R interval during orthostatic experiment in panic disorder patients before and after treatment.MethodsWe assessed heart rate variability in 19 patients with panic disorder before and after 6-weeks treatment with antidepressants combined with CBT and 18 healthy controls. They were regularly assessed on the CGI, BAI and BDI. Heart rate variability was assessed during 5 min standing, 5 min supine and 5 min standing positions before and after the treatment. Power spectra were computed using a fast Fourier transformation for very low frequency - VLF (0.0033 - 0.04 Hz), low-frequency - LF (0.04-0.15 Hz) and high frequency - HF (0.15-0.40 Hz) powers.Results19 panic disorder patients entered a 6-week open-label treatment study with combination of SSRI and cognitive behavioral therapy. A combination of CBT and pharmacotherapy proved to be the effective treatment of patients. They significantly improved in all rating scales. There were highly statistical significant differences between panic patients and control group in all components of power spectral analysis in 2nd and in two component of 3rd (LF and HF in standing) positions. There was also statistically significant difference between these two groups in LF/HF ratio in supine position (2nd). During therapy there was tendency to increasing values in all three positions in components of HRV power spectra, but there was only statistically significant increasing in HF1 component.Supported by project IGA MZ ČR NS 10301-3/2009

scholarly journals Autonomic Conditions in Tinnitus and Implications for Korean Medicine

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Eun Ji Choi ◽  
Younghee Yun ◽  
Seungyeon Yoo ◽  
Kyu Seok Kim ◽  
Jeong-Su Park ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Retrospective Chart Review ◽  
Frequency Component ◽  
Total Power ◽  
High Frequency Component ◽  
Chronic Patients ◽  
Research Attention ◽  
Korean Medicine ◽  
Significant Difference

Tinnitus patients suffer from not only auditory sensations but also physical, mental, and social difficulties. Even though tinnitus is believed to be associated with the autonomic nervous system, changes in autonomic conditions in tinnitus patients are not receiving much research attention. The aims of this study were to investigate the autonomic condition of tinnitus patients and to consider Korean medicine in the treatment of tinnitus with an evidence-based approach. We performed a retrospective chart review and compared the heart rate variability (HRV) parameters of 40 tinnitus patients (19 acute and 21 chronic) and 40 healthy controls. In tinnitus patients, the power of the high frequency component and total power of the HRV significantly decreased(P<0.05), and the low frequency to high frequency ratio significantly increased(P<0.05). There was no significant difference between the acute and chronic patients. When comparing each group with the controls, there was a tendency that the longer the duration of tinnitus was, the larger the observed HRV change was. In conclusion, tinnitus patients have vagal withdrawal and sympathetic overactivity, and chronic tinnitus more strongly affects autonomic conditions than acute tinnitus. This study provides evidence for Korean medical treatments of tinnitus, such as acupuncture and Qi-training, that cause modulation of cardiac autonomic function.

Frequency-dependent velocity analysis and offset-dependent low-frequency amplitude anomalies from hydrocarbon-bearing reservoirs in the southern North Sea, Norwegian sector

Geophysics ◽  
2017 ◽  
Vol 82 (6) ◽  
pp. N51-N60 ◽  
Author(s):  
Sayyid Suhail Ahmad ◽  
R. James Brown ◽  
Alejandro Escalona ◽  
Børge O. Rosland
Keyword(s):  
North Sea ◽  
High Frequency ◽  
Spectral Decomposition ◽  
Low Frequency ◽  
Velocity Analysis ◽  
Frequency Dependent ◽  
Lower Velocity ◽  
The North ◽  
Significant Difference ◽  
The North Sea

Our aim was to identify some of the characteristics of low-frequency anomalies. Specifically, we have looked, in 3D broadband data from the North Sea, for any offset dependence in these anomalies and any frequency-related change in normal moveout (NMO) velocity that could influence stacking power over different frequencies. After high-resolution spectral decomposition, two types of low-frequency anomaly have been identified associated with hydrocarbon-bearing reservoirs: (1) at the reservoir top and (2) below the reservoir, with a time delay of approximately 100–200 ms. Both types of anomalies indicate offset dependence. On the near-offset stacks, they are relatively strong, but they tend to be absent on the far-offset stacks. In addition, horizon velocity analysis, which was performed along the horizons picked at the tops of reservoir and nonreservoir intervals, has revealed frequency-dependent NMO velocity. For nonreservoir events, we found no significant difference between the NMO velocities for the low-frequency and high-frequency filtered common-midpoint gathers. However, along the anomalously low-frequency events observed at the tops of, and below, oil-bearing reservoirs, lower velocity is observed for low-frequency and higher velocity for high-frequency filtered gathers. If these properties turn out to be universally typical, increased understanding and inclusion of them could lead to improved workflows and help increase the reliability of low-frequency analysis as a hydrocarbon indicator.

scholarly journals Depression is closely associated with discoordination between the heart rate variability and physical acceleration in free-moving older women

2020 ◽  
Author(s):  
Kentaro Taniguchi ◽  
Akito Shimouchi ◽  
Naoya Jinno ◽  
Akitoshi Seiyama
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Psychological Distress ◽  
Older Women ◽  
High Frequency ◽  
General Health Questionnaire ◽  
Low Frequency ◽  
Adult Women ◽  
Significant Difference ◽  
Normalized Units

Abstract Background We investigated the relationship between psychological distress and the coordination of heart rate variability (HRV) and physical acceleration (PA) during free-moving days in women. Methods Ninety-five adult women were divided into younger and older groups. The younger group comprised 50 women (22–59 years), and the older group comprised 45 women (≥ 60 years). HRV and PA data were simultaneously obtained every minute for 24 h during the free-moving day. The ratios of low frequency/high frequency and high frequency in normalized units were used as HRV indices. We defined %Lag0 as the % frequency of the lag = 0 min between HRV and PA in 1 h. The General Health Questionnaire 28 (GHQ28) was used to evaluate the effects of psychological distress and depression. Results In the hour before the night’s sleep, %Lag0 was significantly lower in older women with depression (GHQ28 subscale D) than in older women without depression (p < 0.05). However, no significant difference between %Lag0 and depression status was observed in the hour after waking in older women. Conclusions The results suggest that impairments in coordination between HRV and PA are associated with depression in older women, particularly in the hour before a night’s sleep on free-moving days.

scholarly journals Comparison of Heart Rate Variability between Shift and Rest Days in Nurses Working at Coronary Intensive Care Unit

Acta Medica ◽  
2021 ◽  
pp. 1-7
Author(s):  
Mehmet Ozgeyik ◽  
Taner Sen ◽  
Mehmet Ali Astarcioglu ◽  
Mufide Okay ◽  
Abdulkadir Uslu
Keyword(s):  
Intensive Care Unit ◽  
Heart Rate ◽  
Heart Rate Variability ◽  
Intensive Care ◽  
Circadian Rhythm ◽  
High Frequency ◽  
Low Frequency ◽  
Significant Difference ◽  
Intensive Care Unit Nurses ◽  
Cortisol Release

Objective: Stress of working conditions change the circadian rhythm and body’s autonomic functions. Heart rate variability is a simple and noninvasive method that reflects the heart’s autonomic system. In this study, we analyzed the rhythm differences of intensive care unit nurses between 24 hours shift and rest days. Materials and Methods: 51 nurses working in intensive care units of our center were included in the study. The nurses were divided into two groups as study and control groups according to the shift and rest days for 24 hours holter recordings, respectively. Results: Heart rate parameters were under parasympathic and sympathic dominance in rest and shift days, respectively. Although normalized high frequency, normalized low frequency and low frequency/high frequency ratio values were parallel to the shift and rest days at 24-hour intervals, inverse correlations were observed between 03.00- 08.00 hours. No statistically significant difference was seen in circadian rhythm between shift and rest days. Heart rate parameters generally showed similar pattern of circadian rhythm irrespective of the working status of the participants. Sympathetic activity was significantly higher in the day period than the night period in the shift days however there was no difference within resting group. Conclusion: Slight increase in sympathetic system activity and marked decrease in parasympathetic activity during 03-05 o’clock were apparent in shift days. This increase was attributed to early cortisol release.

scholarly journals Supervivencia intracelular de cepas de Mycobacterium bovis de alta y baja frecuencia probado en un modelo de macrófagos bovinos

2021 ◽  
Vol 12 (2) ◽  
pp. 487-502
Author(s):  
Alejandro Nava-Vargas ◽  
Feliciano Milián-Suazo ◽  
Germinal Jorge Cantó-Alarcón ◽  
José A. Gutiérrez-Pabello
Keyword(s):  
Mycobacterium Bovis ◽  
Bovine Tuberculosis ◽  
High Frequency ◽  
Low Frequency ◽  
Intracellular Survival ◽  
Strain Identification ◽  
Cattle Population ◽  
Intracellular Growth ◽  
Colony Forming Units ◽  
Significant Difference

Bovine tuberculosis is a disease caused by Mycobacterium bovis that affects cattle and other species, including humans. Mycobacterium bovis resides mainly in macrophages, so bacilli survival within macrophages is related to virulence. Isolation and strain identification are important for disease control. However, little is known about virulence of the circulating strains in cattle populations. Therefore, the aim of this study was to compare the intracellular survival of Mycobacterium bovis strains with high and low frequency genotypes in cattle in Mexico. Four high frequency genotypes and four low frequency genotypes were identified and subjected to intracellular survival assays in bovine macrophages. Results showed that the phagocytosis proportion was approximately 63 % for all strains. There were no significant differences in the average Colony Forming Units (CFUs) in phagocytosis and survival between the high and low frequency groups; however, when the CFU average of phagocytosis was compared with the survival, significant differences were found in both groups. In intracellular growth, a significant difference was observed between low and high frequency strains, and between low frequency strains. Finally, the intracellular growth average of the groups was analyzed showing no significant difference. These results suggest that the frequency of the genotype in cattle population is not related to the intracellular survival and the virulence of the M. bovis strains.

scholarly journals Effect of personality traits on sensitivity, annoyance and loudness perception of low- and high-frequency noise

2020 ◽  
pp. 146134842094581
Author(s):  
Milad Abbasi ◽  
Mohammad Osman Tokhi ◽  
Mohsen Falahati ◽  
Saeid Yazdanirad ◽  
Maryam Ghaljahi ◽  
...  
Keyword(s):  
Personality Traits ◽  
High Frequency ◽  
Low Frequency ◽  
Analysis Of Covariance ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
High Frequency Noise ◽  
Noise Annoyance ◽  
Significant Difference ◽  
Frequency Components

This paper presents investigations into a comparative assessment of the effects of low- and high-frequency noise in relation to personality traits. The high- and low-frequency noises used are produced in the research laboratory using CoolEdit software. In all, 80 candidates were exposed to equivalent continuous sound pressure level of 65 dBA of low- and high-frequency noise in an acoustic room with a 2-week interval. After 1 hour of exposure to noise, participants were asked to complete noise annoyance scale, Weinstein noise sensitivity questionnaire and loudness perception. The results obtained indicate that there is a significant difference between annoyance and perception of low-frequency noise in comparison to annoyance and perception of high-frequency noise, but no significant difference is noted between sensitivity to low- and high-frequency noise. The multivariate analysis of covariance test is applied, which reveals that personality traits have a significant effect on sensitivity to low- and high-frequency noise, annoyance due to low- and high-frequency noise, loudness perception of low-frequency noise, but no interaction effects are found. It is further shown that personality traits are more effective on sensitivity, annoyance and loudness perception to high-frequency noise than those of low-frequency noise, and such effects are not only influenced by severity of noise but also by personality traits and frequency components.

scholarly journals Pulse Rate Variability in Emergency Physicians During Shifts: Pilot Cross-Sectional Study (Preprint)

2019 ◽  
Author(s):  
Gregory Andrew Peters ◽  
Matthew L Wong ◽  
Joshua W Joseph ◽  
Leon D Sanchez
Keyword(s):  
Pulse Rate ◽  
High Frequency ◽  
Low Frequency ◽  
Fourth Quarter ◽  
Emergency Physicians ◽  
Pulse Rate Variability ◽  
Significant Difference ◽  
Standard Pulse ◽  
Academic Year ◽  
Frequency Power

BACKGROUND The high prevalence of physician burnout, particularly in emergency medicine, has garnered national attention in recent years. Objective means of measuring stress while at work can facilitate research into stress reduction interventions, and wearable photoplethysmography (PPG) technology has been proposed as a potential solution. However, the use of low-burden wearable biosensors to study training and clinical practice among emergency physicians (EP) remains untested. OBJECTIVE This pilot study aimed to (1) determine the feasibility of recording on-shift photoplethysmographic data from EP, (2) assess the quality of these data, and (3) calculate standard pulse rate variability (PRV) metrics from the acquired dataset and examine patterns in these variables over the course of an academic year. METHODS A total of 21 EP wore PPG biosensors on their wrists during clinical work in the emergency department during a 9-hour shift. Recordings were collected during the first quarter of the academic year, then again during the fourth quarter of the same year for comparison. The overall rate of usable data collection per time was computed. Standard pulse rate (PR) and PRV metrics from these two time points were calculated and entered into Student <italic>t</italic> tests. RESULTS More than 400 hours of data were entered into these analyses. Interpretable data were captured during 8.54% of the total recording time overall. In the fourth quarter of the academic year compared with the first quarter, there was no significant difference in median PR (75.8 vs 76.8; <italic>P</italic>=.57), mean R-R interval (0.81 vs 0.80; <italic>P</italic>=.32), SD of R-R interval (0.11 vs 0.11; <italic>P</italic>=.93), root mean square of successive difference of R-R interval (0.81 vs 0.80; <italic>P</italic>=.96), low-frequency power (3.5×103 vs 3.4×103; <italic>P</italic>=.79), high-frequency power (8.5×103 vs 8.3×103; <italic>P</italic>=.91), or low-frequency to high-frequency ratio (0.42 vs 0.41; <italic>P</italic>=.43), respectively. Power estimates for each of these tests exceeded .90. A secondary analysis of the resident-only subgroup similarly showed no significant differences over time, despite power estimates greater than .80. CONCLUSIONS Although the use of PPG biosensors to record real-time physiological data from EP while providing clinical care seems operationally feasible, this study fails to support the notion that such an approach can efficiently provide reliable estimates of metrics of interest. No significant differences in PR or PRV metrics were found at the end of the year compared with the beginning. Although these methods may offer useful applications to other domains, it may currently have limited utility in the contexts of physician training and wellness.

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