• Title/Summary/Keyword: Physiological models

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Allometric Modeling for Leaf Area and Leaf Biomass Estimation of Swietenia mahagoni in the North-eastern Region of Bangladesh

  • Das, Niamjit
    • Journal of Forest and Environmental Science
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    • v.30 no.4
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    • pp.351-361
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    • 2014
  • Leaf area ($A_0$) and leaf biomass ($M_0$) estimation are significant prerequisites to studying tree physiological processes and modeling in the forest ecosystem. The objective of this study was to develop allometric models for estimating $A_0$ and $M_0$ of Swietenia mahagoni L. from different tree parameters such as DBH and tree height of mahogany plantations in the northeastern region of Bangladesh. A total of 850 healthy and well formed trees were selected randomly for sampling in the five study sites. Then, twenty two models were developed based on different statistical criteria that propose reliable and accurate models for estimating the $A_0$ and $M_0$ using non-destructive measurements. The results exposed that model iv and xv were selected on a single predictor of DBH and showed more statistically accuracy than other models. The selected models were also validated with an additional test data set on the basis of linear regression and t-test for mean difference between observed and predicted values. After that, a comparison between the best logarithmic and non-linear allometric model shows that the non-linear model produces systematic biases and underestimates $A_0$ and $M_0$ for larger trees. As a result, it showed that the bias-corrected logarithmic model iv and xv can be used to help quantify forest structure and functions, particularly valuable in future research for estimating $A_0$ and $M_0$ of S. mahagoni in this region.

Evaluation of dynamic muscle fatigue model to predict maximum endurance time during forearm isometric contraction (전완의 등척성 수축시 최대근지구력시간을 예측하기 위한 동적근피로모델의 평가)

  • Kiyoung, Lee
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.6
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    • pp.433-439
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    • 2022
  • Muscle fatigue models to predict maximum endurance time (MET) are broadly classified as either 'empirical' or 'theoretical'. Empirical models are based on fitting experimental data and theoretical models on mathematical representations of physiological process. This paper examines the effectiveness of dynamic muscle fatigue model as theoretical model to predict maximum endurance time during forearm isometric contraction. Forty volunteers (20 females, 20 males) are participated in this study. Empirical models (exponential model and power model) and theoretical model (dynamic muscle fatigue model) are used to compare. Mean absolute deviation (MAD), correlation coefficient (r) and intraclass correlation (ICC) are calculated between theoretical model and empirical models. MAD are below 3.5%p, r and ICC are above 0.93 and 0.87, respectively. This results demonstrate that dynamic muscle fatigue model as theoretical model is valid to predict MET.

Survival Prediction of Rats with Hemorrhagic Shocks Using Support Vector Machine (지원벡터기계를 이용한 출혈을 일으킨 흰쥐에서의 생존 예측)

  • Jang, K.H.;Choi, J.L.;Yoo, T.K.;Kwon, M.K.;Kim, D.W.
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.1-7
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    • 2012
  • Hemorrhagic shock is a common cause of death in emergency rooms. Early diagnosis of hemorrhagic shock makes it possible for physicians to treat patients successfully. Therefore, the purpose of this study was to select an optimal survival prediction model using physiological parameters for the two analyzed periods: two and five minutes before and after the bleeding end. We obtained heart rates, mean arterial pressures, respiration rates and temperatures from 45 rats. These physiological parameters were used for the training and testing data sets of survival prediction models using an artificial neural network (ANN) and support vector machine (SVM). We applied a 5-fold cross validation method to avoid over-fitting and to select the optimal survival prediction model. In conclusion, SVM model showed slightly better accuracy than ANN model for survival prediction during the entire analysis period.

Physiological effects of copper on the freshwater alga Closterium ehrenbergii Meneghini (Conjugatophyceae) and its potential use in toxicity assessments

  • Wang, Hui;Sathasivam, Ramaraj;Ki, Jang-Seu
    • ALGAE
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    • v.32 no.2
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    • pp.131-137
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    • 2017
  • Although green algae of the genus Closterium are considered ideal models for testing toxicity in aquatic ecosystems, little data about the effects of toxicity on these algal species is currently available. Here, Closterium ehrenbergii was used to assess the acute toxicity of copper (Cu). The median effective concentration ($EC_{50}$) of copper sulfate based on a dose response curve was $0.202mg\;L^{-1}$, and reductions in photosynthetic efficiency ($F_v/F_m$ ratio) of cells were observed in cultures exposed to Cu for 6 h, with efficiency significantly reduced after 48 h (p < 0.01). In addition, production of reactive oxygen species significantly increased over time (p < 0.01), leading to damage to intracellular organelles. Our results indicate that Cu induces oxidative stress in cellular metabolic processes and causes severe physiological damage within C. ehrenbergii cells, and even cell death; moreover, they clearly suggest that C. ehrenbergii represents a potentially powerful test model for use in aquatic toxicity assessments.

Effect of a polyherbal formulation (Diarun plus) on the glycemic status modified by physiological means in non-diabetic mice and rats

  • G, Senthilvel;M, Jegadeesan;P, Thirugnanasambantham;E, Mayisvren;M, Balasubramanian;N, Narayanan;S, Viswanathan;Austin, Anoop
    • Advances in Traditional Medicine
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    • v.7 no.2
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    • pp.128-132
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    • 2007
  • Diarun plus, a polyherbal formulation containing herbal ingredients of folkloric Antidiabetic effect, was investigated for its effect on glycemic status in rats and mice. In contrast to conventional chemical induced diabetic animal models, changes in glycemic states were induced by physiological maneuvers. Results revealed that in euglycemic animals Diarun plus elicited little change (-10 to +10%), which was insignificant. In food deprivation/swim exercise induced hypoglycemia, Diarun plus reduced the degree of hypoglycemia in both rats and mice (from 38% to 27% in rats and 45% to 32% in mice). Similarly, the marked hyperglycemia induced by dextrose (70% in rats and 95% in mice) was reduced markedly to 8% and 25% respectively. The findings of the present study suggests that the ingredients of Diarun plus have the unique property of maintaining near euglycemic state irrespective of the altered glycemic state, and that have no significant effect in euglycemic condition.

The Molecular Functions of RalBP1 in Lung Cancer

  • Lee, Seunghyung
    • Biomedical Science Letters
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    • v.20 no.2
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    • pp.49-55
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    • 2014
  • RalBP1 is an ATP-dependent non-ABC transporter, responsible for the major transport function in many cells including many cancer cell lines, causing efflux of glutathione-electrophile conjugates of both endogenous metabolites and environmental toxins. RalBP1 is expressed in most human tissues, and is over-expressed in non-small cell lung cancer cell lines and in many other tumor types. Blockade of RalBP1 by various approaches has been shown to increase sensitivity to radiation and chemotherapeutic drugs, leading to cell apoptosis. In xenograft tumor models in mice, RalBP1 blockade or depletion results in complete and sustained regression across many cancer cell types including lung cancer cells. In addition to its transport function, RalBP1 has many other cellular and physiological functions, based on its domain structure which includes a unique Ral-binding domain and a RhoGAP catalytic domain, as well as docking sites for multiple signaling proteins. Additionally, RalBP1 is also important for stromal cell function in tumors, as it was recently shown to be required for efficient endothelial cell function and angiogenesis in solid tumors. In this review, we discuss the cellular and physiological functions of RalBP1 in normal and lung cancer cells.

The Effects of Breast Milk Olfactory Stimulation on Physiological Responses, Oral Feeding Progression and Body Weight in Preterm Infants (모유후각자극이 미숙아의 생리적 반응, 구강수유 진행 및 체중에 미치는 영향)

  • Lee, Eun Jee
    • Journal of Korean Academy of Nursing
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    • v.49 no.2
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    • pp.126-136
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    • 2019
  • Purpose: This study was conducted to evaluate the effect of breast milk olfactory stimulation on physiological responses, oral feeding progression, and body weight in preterm infants. Methods: A repeated measures design with nonequivalent control group was used. The participants were healthy, preterm infants born at a gestational age of 28~32 weeks; 12 in the experimental group and 16 in the control group. Data were collected prospectively in the experimental group, and retrospectively in the control group, by the same methods. Breast milk olfactory stimulation was provided 12 times over 15 days. The data were analyzed using the chi-square test, Mann-Whitney U test, Wilcoxon signed rank test and linear mixed models using SPSS 19. Results: The gastric residual volume (GRV) of the experimental group was significantly less than that of the control group. The heart rate, oxygen saturation, respiration rate, transition time to oral feeding, and body weight were not significantly different between the two groups. Conclusion: These findings indicate that breast milk olfactory stimulation reduces GRV and improves digestive function in preterm infants without inducing distress.

Biological Activity Analysis of Potato-derived Polar Compounds (감자 유래 극성화합물의 생리활성 분석)

  • Kim, Dae Yoon;Nam, Jung Hwan;Lee, Jae Kwon
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.62-62
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    • 2019
  • Natural substances have various physiological activities. Substances isolated from natural substances are known to be safer and more potent than pharmaceuticals. Potatoes not only act as energy sources but also contain active ingredients such as vitamins and minerals. In particular, the potato contains a large amount of polar compounds, including the saponin in the polar compounds, and the physiological activity of the saponins, such as immunity enhancement, antioxidant and anti-inflammatory is known. In this study, the antioxidative activity of polar compounds from five potatoes was examined by chemical base anti-oxidation assay and cell based anti-oxidation assay. In the chemical base anti-oxidation assay, DPPH experiment showed activity in the order of Hongyoung, Haryung, Seohong, Sumi, and Jayoung. In the LPA experiment, IC50 was lower in the order of Jayoung, Seohong, Sumi, Hongyoung, and Haryung. In the cell based anti-oxidation assay, the smallest amount of ROS was generated when the compound was derived from Haryung and hongyoung, and strong SOD activity was observed in Sumi and Jayoung. The results of this study reveal the antioxidative effect of polar compounds extracted from various kind of potatoes, which will enable the acquisition of new bioactive candidates and the establishment of new profit generation models for farmers.

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Real-world multimodal lifelog dataset for human behavior study

  • Chung, Seungeun;Jeong, Chi Yoon;Lim, Jeong Mook;Lim, Jiyoun;Noh, Kyoung Ju;Kim, Gague;Jeong, Hyuntae
    • ETRI Journal
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    • v.44 no.3
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    • pp.426-437
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    • 2022
  • To understand the multilateral characteristics of human behavior and physiological markers related to physical, emotional, and environmental states, extensive lifelog data collection in a real-world environment is essential. Here, we propose a data collection method using multimodal mobile sensing and present a long-term dataset from 22 subjects and 616 days of experimental sessions. The dataset contains over 10 000 hours of data, including physiological, data such as photoplethysmography, electrodermal activity, and skin temperature in addition to the multivariate behavioral data. Furthermore, it consists of 10 372 user labels with emotional states and 590 days of sleep quality data. To demonstrate feasibility, human activity recognition was applied on the sensor data using a convolutional neural network-based deep learning model with 92.78% recognition accuracy. From the activity recognition result, we extracted the daily behavior pattern and discovered five representative models by applying spectral clustering. This demonstrates that the dataset contributed toward understanding human behavior using multimodal data accumulated throughout daily lives under natural conditions.

Physiological Roles of Adipokines, Hepatokines, and Myokines in Ruminants

  • Roh, Sang-Gun;Suzuki, Yutaka;Gotoh, Takafumi;Tatsumi, Ryuichi;Katoh, Kazuo
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.1
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    • pp.1-15
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    • 2016
  • Since the discovery of leptin secreted from adipocytes, specialized tissues and cells have been found that secrete the several peptides (or cytokines) that are characterized to negatively and positively regulate the metabolic process. Different types of adipokines, hepatokines, and myokines, which act as cytokines, are secreted from adipose, liver, and muscle tissue, respectively, and have been identified and examined for their physiological roles in humans and disease in animal models. Recently, various studies of these cytokines have been conducted in ruminants, including dairy cattle, beef cattle, sheep, and goat. Interestingly, a few cytokines from these tissues in ruminants play an important role in the post-parturition, lactation, and fattening (marbling) periods. Thus, understanding these hormones is important for improving nutritional management in dairy cows and beef cattle. However, to our knowledge, there have been no reviews of the characteristics of these cytokines in beef and dairy products in ruminants. In particular, lipid and glucose metabolism in adipose tissue, liver tissue, and muscle tissue are very important for energy storage, production, and synthesis, which are regulated by these cytokines in ruminant production. In this review, we summarize the physiological roles of adipokines, hepatokines, and myokines in ruminants. This discussion provides a foundation for understanding the role of cytokines in animal production of ruminants.