• Title/Summary/Keyword: Minimal variability

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Species Composition and Vertical Distribution of Marine Algal Communities at the Taean Peninsula of the West Coast of Korea (서해안 태안반도 해조군집의 종조성과 수직분포)

  • Ahn, Jung Kwan;Yoo, Kyong Dong;Oh, Ji Chul;Lee, Jae Il;Yoon, Hee Dong;Kim, Young Hwan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.1
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    • pp.55-64
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    • 2017
  • Seasonal variability in algal community structure was examined at the intertidal zones of five study sites on the Taean Peninsula, on the western coast of Korea, from February 2014 to November 2015. A total of 118 species of marine algae, comprising 17 green, 24 brown and 77 red algae, were identified. The maximum number of species was observed at the Mohang site (75 species), and the minimum at the Yeonpo site (46 species). The seaweed biomass was $160.24g\;dry\;wt./m^2$ on average, and was maximal at Uihang ($519.04g\;dry\;wt./m^2$) and minimal at Yeonpo ($19.03g\;dry\;wt./m^2$). Based on biomass, the dominant seaweeds at Taean peninsula were Sargassum thunbergii and Corallina pilulifera. Community indices were as follows: richness index (R), 3.21-5.01; evenness index (J'), 0.33-0.38; and diversity index (H'), 0.90-1.12. Based on evaluation of the environmental states by the community indices, the ecological evaluation index (EEI) of Taean peninsula was "moderate". The overall species and biomass of seaweeds decreased after the oil spill. However, Hakampo previously showed a similar algal community structure. In conclusion, the algal community was temporarily affected by the oil spill, but rapidly recovered.

Seasonal Variability of Marine Algal Flora and Community Structure at Jungjado, on the South Coast of Korea (한국 남해안 정자도의 해조상 및 군집구조 변화)

  • Yoo, Hyun Il;Jeong, Bo Kyung;Park, Jeong Kwang;Heo, Jin Suk;Park, Mi-Seon;Choi, Han Gil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.6
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    • pp.927-934
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    • 2014
  • Marine algal flora and community structure were seasonally examined at Jungjado, on the southern coast of Korea, from July 2007 to May 2008. A total of 112 seaweeds, including 15 green, 24 brown, and 73 red algae, were identified and 33 species were found throughout the year. The average seaweed biomass was 145.78 g dry weight $m^{-2}$, and the biomass was maximal in winter (184.74 g) and minimal in autumn (106.17 g). The dominant and subdominant species in terms of biomass were Sargassum thunbergii and Grateloupia elliptica in summer, S. thunbergii and Corallina pilulifera in autumn, S. thunbergii and Chondracanthus intermedius in winter, and Sargassum fusiforme and G. elliptica in spring. The vertical distribution patterns of seaweeds from the upper to lower intertidal zones at Jungjado were S. thunbergii - Ulva conglobata - Gelidium elegans in summer; Caulacantus ustulatus - Chondria crassicaulis - C. pilulifera in autumn; Ulva australis - S. thunbergii - G. elliptica in winter; and Gloiopeltis tenax - S. fusiforme - G. elliptica in spring. Seasonally the evenness, richness, and diversity indices tended to have their highest values during the winter and their lowest values in the summer. However, the dominant index was recorded as lowest in winter and highest in the summer. The C/P, R/P, and (R+C)/P values reflecting the flora characteristics were 0.58, 3.04, and 3.62, respectively.

Inter- and Intra-Observer Variability of the Volume of Cervical Ossification of the Posterior Longitudinal Ligament Using Medical Image Processing Software

  • Shin, Dong Ah;Ji, Gyu Yeul;Oh, Chang Hyun;Kim, Keung Nyun;Yoon, Do Heum;Shin, Hyunchul
    • Journal of Korean Neurosurgical Society
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    • v.60 no.4
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    • pp.441-447
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    • 2017
  • Objective : Computed tomography (CT)-based method of three dimensional (3D) analysis ($MIMICS^{(R)}$, Materialise, Leuven, Belgium) is reported as very useful software for evaluation of OPLL, but its reliability and reproducibility are obscure. This study was conducted to evaluate the accuracy of $MIMICS^{(R)}$ system, and inter- and intra-observer reliability in the measurement of OPLL. Methods : Three neurosurgeons independently analyzed the randomly selected 10 OPLL cases with medical image processing software ($MIMICS^{(R)}$) which create 3D model with Digital Imaging and Communication in Medicine (DICOM) data from CT images after brief explanation was given to examiners before the image construction steps. To assess the reliability of inter- and intra-examiner intraclass correlation coefficient (ICC), 3 examiners measured 4 parameters (volume, length, width, and length) in 10 cases 2 times with 1-week interval. Results : The inter-examiner ICCs among 3 examiners were 0.996 (95% confidence interval [CI], 0.987-0.999) for volume measurement, 0.973 (95% CI, 0.907-0.978) for thickness, 0.969 (95% CI, 0.895-0.993) for width, and 0.995 (95% CI, 0.983-0.999) for length. The intra-examiner ICCs were 0.994 (range, 0.991-0.996) for volume, 0.996 (range, 0.944-0.998) for length, 0.930 (range, 0.873-0.947) for width, and 0.987 (range, 0.985-0.995) for length. Conclusion : The medical image processing software ($MIMICS^{(R)}$) provided detailed quantification OPLL volume with minimal error of inter- and intra-observer reliability in the measurement of OPLL.

HPLC Determination of Tolperisone in Human Plasma

  • Bae Jung-Woo;Park Young-Seo;Sohn Uy-Dong;Myung Chang-Sun;Ryu Byung-Kwon;Jang Choon-Gon;Lee Seok-Yong
    • Archives of Pharmacal Research
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    • v.29 no.4
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    • pp.339-342
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    • 2006
  • A simple high performance liquid chromatographic (HPLC) method was developed for the determination of tolperisone in human plasma. Tolperisone and internal standard (chlorphenesin) were isolated from 1 mL of plasma using 8 mL of dichlormethane. The organic phase was collected and evaporated under nitrogen gas. The residue was then reconstituted with 300 mL aliquot of mobile phase and a 100 mL aliquot was injected onto the $C_{18}$ reverse-phased column. The mobile phase, $45\%$ methanol containing $1\%$ glacial acetic acid and $0.05\%$ 1-hexanesulfonic acid was run at a flow rate of 1 mL/min. The column effluent was monitored using UV detector at 260 nm. The retention times for tolperisone and the internal standard were approximately 7.1 and 8.4 min, respectively. The standard curve was linear with minimal intra-day and inter-day variability. The quantification limit of tolperisone in human plasma was 10 ng/ mL. The proposed method has been applied to the determination of pharmacokinetic profile of tolperisone in Koreans. The T max of tolperisone in Koreans $(0.94{\pm}0.42\;h)$ was not significantly differ from that reported in Europeans (0.5-1 h), but the mean half-life in Koreans $(1.14{\pm}0.27\;h)$ was shorter than that in Europeans $(2.56{\pm}0.2\;h)$. The proposed HPLC method is simple, accurate, reproducible and suitable for pharmacokinetic study of tolperisone.

Monthly variations in macroalgal flora and community structure in Hampyong Bay, Southwestern Coast of Korea (한국 남서해안 함평만의 월별 해조상 및 군집구조 변화)

  • Oh, Byoung-Geon;Choi, Han Gil
    • Korean Journal of Environmental Biology
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    • v.39 no.1
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    • pp.81-87
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    • 2021
  • The monthly variability in marine algal flora and community structure was examined in the intertidal zones of Doripo, and the biomass of an edible alga, Ulva prolifera, at Gaip-ri of Hampyong Bay on the southwestern coast of Korea was investigated over one year from April 2008 to March 2009. A total of 22 seaweeds were identified including five green, four brown, and 13 red algae. Based on importance value, Ulva australis was dominant over the year and the subdominant species were Ulva linza and Caulacanthus ustulatus at the Doripo coast of Hampyong Bay. The vertical distribution in terms of importance values was in the order of Ulva linza - C. ustulatus - U. australis - Sargassum thunbergii from the upper to the lower intertidal zones. The biomass of U. prolifera ranged between 2.4-98.2 g dry wt. m-2, with a maximum in June and a minimal in November. In the field, U. prolifera biomass could be positively related to seawater temperature. However, further research on the association between biomass and other environmental factors such as nutrients and light intensity is required.

Effect of Transient Isokinetic Exercise on Cardiac Autonomic Nervous Modulation and Muscle Properties (일회성 등속성 운동이 심장 자율신경 조절 및 근속성에 미치는 영향)

  • Soo-Kyoung Park;Si-Eun Park
    • Journal of The Korean Society of Integrative Medicine
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    • v.11 no.4
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    • pp.27-39
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    • 2023
  • Purpose : The aim of this study was to identify the influence of transient isokinetic exercise on cardiac autonomic modulation and muscle properties in healthy male subjects. Methods : Twenty-eight healthy males underwent isokinetic exercise of both knee joints using a Biodex systems 3 isokinetic dynamometer with an angular velocity of 60 °/sec. The changes in activity of the autonomic nervous system, as determined by heart rate variability (HRV), and in muscle properties were evaluated at three times: pre-exercise, immediately post-exercise, and 10 min post-exercise. Results : The time domain analysis of HRV revealed significant changes in the beat count and mean and minimal heart rate (HR) measured at pre-exercise, immediately post-exercise, and 10 min post-exercise (p<.001). The beat count and mean HR were markedly increased immediately post-exercise compared to pre-exercise, but then significantly decreased at 10 min post-exercise (p<.001). All parameters of the frequency domain were significantly altered by isokinetic exercise (p<.01). The low frequency/high frequency (LF/HF) ratio, as an index for the sympathovagal balance, was elevated by exercise and remained at a similarly high level at 10 min post-exercise (p<.01). The muscle properties of rectus femoris were changed as follows: Muscle tone and stiffness were significantly increased between pre-exercise and immediately post-exercise (p<.001), and between pre-exercise and at 10 min post-exercise (p<.001). Whereas, the elasticity showed no significant change. Conclusion : These results demonstrated that transient isokinetic exercise could induce changes in cardiac autonomic control and muscle properties. In particular, up-regulation of LF/HF ratio after exercise signifies thus enhanced sympathetic modulation by isokinetic exercise. Therefore, it is needed to understand the cardiovascular risks that may arise during isokinetic exercise for providing the basic evidence to establish appropriate isokinetic exercise protocols as effective rehabilitation exercises.

Experimental analysis of meandering channel development processes with floodplain vegetation (홍수터 식생에 의한 저수로 사행 발달과정 실험적 분석)

  • Jang, Chang-Laea
    • Journal of Korea Water Resources Association
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    • v.56 no.12
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    • pp.895-903
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    • 2023
  • This study investigates the impact of riparian vegetation in the floodplain on channel stability, changes in bend curvature, and meandering channel migration. In channels with riparian vegetation, over time, meander width remains relatively constant, but selective bank erosion leads to meander development and downstream movement. During this process, bank erosion and changes in the riverbed are not significant, and the channel maintains relatively constant conditions with reduced sediment discharge and minimal variability. As the density of vegetation increases, bank erosion rates decrease. The erosion rates along the riverbanks increase with the density of vegetation on the floodplain, thus affecting the development of meanders. This factor notably contributes to enhancing riverbank stability and influencing channel changes through floodplain vegetation. Bank erosion rates and dimensionless bend curvature are greatest when there is no riparian vegetation but decrease in conditions with vegetation. Furthermore, the relationship between lateral migration rate and dimensionless bend curvature is similar to that of bank erosion rates. Therefore, riparian vegetation enhances channel stability, influencing bank erosion, meander curvature, and meander migration.

Physical, Mechanical and Durability Properties of the Quartzite Units of Central Nepal Lesser Himalaya

  • Dinesh Raj Sharma;Naresh Kazi Tamrakar;Upendra Baral
    • The Journal of Engineering Geology
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    • v.34 no.1
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    • pp.67-105
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    • 2024
  • This study compares the quartzites of four quartzite units: The Fagfog Quartzite, Dunga Quartzite (member of the Robang Formation), Pandrang Quartzite (member of the Kalitar Formation) and the Chisapani Quartzite. The analysis shows variations in flakiness and elongation, as the Fagfog Quartzite displays low flakiness whereas the Pandrang and the Chisapani have moderate and the Dunga Quartzite has shown variations. The density values of the four quartzite units remain consistent, indicating uniform physical properties and porosity levels. However, bulk density values differ among the quartzites, suggesting variations in particle arrangement, porosity, and density. Regarding strength measures, the Pandrang and the Chisapani Quartzite have higher strength characteristics as compared to the Fagfog and the Dunga Quartzites. The Pandrang Quartzite has the highest average point load strength index, classifying it as "Extremely Strong". The resistance to impact and crushing forces varies among the quartzites, with lower Aggregate Impact Value (AIV) and Aggregate Crushing Value (ACV) indicating higher strength and durability. Durability tests show that the Fagfog Quartzite has high durability against slaking, with a slight decrease observed after the fifth cycle. The Dunga Quartzite shows varying degrees of weathering, while the Pandrang and the Chisapani Quartzite have minimal weight changes, indicating strong resistance to weathering. Magnesium sulfate soundness tests indicate high durability and resistance to degradation for all four units. The Los Angeles abrasion value (LAAV) tests indicate favorable resistance to abrasion for the majority of the Fagfog, Dunga, and the Pandrang Quartzites samples, while Chisapani Quartzite shows more variability in LAAV values. The Pandrang Quartzite shows a higher proportion of elongated particles but lower flakiness index values as compared to Fagfog and Dunga Quartzites while Chisapani Quartzite stands out with a significantly higher presence of flaky particles and lower elongation index values. Mechanically, the Fagfog and Dunga Quartzite show higher strength and better resistance to abrasion and freeze and thaw. The Pandrang Quartzite shows moderate resistance to crushing and sudden effect, while the Chisapani Quartzite has variable resistance to effect. This comparative study emphasizes the diversity and complexity of quartzite rock types, showing the need for comprehensive characterization and assessment to determine their suitability for specific applications.

NIR-TECHNOLOGY FOR RATIONALE SOIL ANALYSIS WITH IMPLICATIONS FOR PRECISION AGRICULTURE

  • Stenberg, Bo
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1061-1061
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    • 2001
  • The scope of precision agriculture is to reach the put up cultivation goals by adjusting inputs as precise as possible after what is required by the soil and crop potentials, on a high spatial resolution. Consequently, precision agriculture is also often called site specific agriculture. Regulation of field inputs “on the run” has been made possible by the GPS (Geographical Position System)-technology, which gives the farmer his exact real time positioning in the field. The general goal with precision agriculture is to apply inputs where they best fill their purpose. Thus, resources could be saved, and nutrient losses as well as the impact on the environment could be minimized without lowering total yields or putting product quality at risk. As already indicated the technology exists to regulate the input based on beforehand decisions. However, the real challenge is to provide a reliable basis for decision-making. To support high spatial resolution, extensive sampling and analysis is required for many soil and plant characteristics. The potential of the NIR-technology to provide rapid, low cost analyses with a minimum of sample preparation for a multitude of characteristics therefore constitutes a far to irresistible opportunity to be un-scrutinized. In our work we have concentrated on soil-analysis. The instrument we have used is a Bran Lubbe InfraAlyzer 500 (1300-2500 nm). Clay- and organic matter-contents are soil constituents with major implications for most properties and processes in the soil system. For these constituents we had a 3000-sample material provided. High performance models for the agricultural areas in Sweden have been constructed for clay-content, but a rather large reference material is required, probably due to the large variability of Swedish soils. By subdividing Sweden into six areas the total performance was improved. Unfortunately organic matter was not as easy to get at. Reliable models for larger areas could not be constructed. However, through keeping the mineral fraction of the soil at minimal variation good performance could be achieved locally. The influence of a highly variable mineral fraction is probably one of the reasons for the contradictory results found in the literature regarding organic matter content. Tentative studies have also been performed to elucidate the potential performance in contexts with direct operational implications: lime requirement and prediction of plant uptake of soil nitrogen. In both cases there is no definite reference method, but there are numerous indirect, or indicator, methods suggested. In our study, field experiments where used as references and NIR was compared with methods normally used in Sweden. The NIR-models performed equally or slightly better as the standard methods in both situations. However, whether this is good enough is open for evaluation.

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Respiratory Sinus Arrhythmia: Methods of Measurement and Interpretations of Tonic and Dynamic Vagal Cardiac Drive Index in Psychophysiology of Emotions

  • Estate M.Sokhadze;Lee, Jong-Mi;Park, Mi-Kyung;Sohn, Jin-Hun
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2000.11a
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    • pp.81-87
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    • 2000
  • Beat-to-beat changes in heart period (heart period variability, HPV) are mediated by fluctuations in autonomic activity. Spectral analysis is used to quantify such fluctuations in the range of 0.15-0.40 Hz (high frequency, HF), which are influenced primarily by parasympathetic factors. These fluctuations are often referred to as RSA (respiratory sinus arrhythmia), the physiological phenomenon extracted by spectral analysis and other methods including histograms of heart rate ( HR), deviations of HR etc. Respiratory sinus arrhythmia indexing with peak-to-valley method suggested by Grossman et at., (1981) yields a simple range statistic and is quantified on breath-by-breath basis, thus being quite sensitive and less dependent on recording time as compared to spectral analysis. It is strongly recommended to use at least 1 min epoch to asses HF component of HPV and at least 2 min fer low frequency (LF) of HPV and even 5 min far valid clinical assessment. Peak-to-valley statistic is limited to RSA index only, but has its pragmatic advantages. Most important is possibility of its application far relatively small epoch analysis. We used short periods (20,30, 40 sec only) and off-line analysis of RSA using ECG and respiration curve this method of assessment and proved that this method is more practically effective. The RSA index was not so far dependent on respiration pattern differences and reflected actual vagal control of HR and were accompanied by low HR under some high stress conditions and in an aversive affective visual stimulation experiments. Another factor that might modulate cardiac chronotropic response is the interaction of sympathetic and parasympathetic inputs on sino-atrial (SA) node level, because responses to vagal influences are known to be proportional to ongoing sympathetic activity, that is so called accentuated antagonism. Since sympathetic outflow (increment of influences on SA) under negative emotions or stress was high in almost all physiological responses, vagal effects on HR could be therefore potentiated, leading to masking of output cardiac response seen in HPV, In the case of moderate sympathetic activation, on the other hand, autonomic interactions in cardiac control appear to be minimal. Thus RSA index appears to be an effective alternative method to assess and measure spectral HPV.

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