• Title/Summary/Keyword: functional response

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DYNAMICS OF A PREY-PREDATOR INTERACTION WITH HASSELL-VARLEY TYPE FUNCTIONAL RESPONSE AND HARVESTING OF PREY

  • BHATTACHARYYA, ANINDITA;MONDAL, ASHOK;PAL, A.K.;SINGH, NIKHITA
    • Journal of applied mathematics & informatics
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    • v.40 no.5_6
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    • pp.1199-1215
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    • 2022
  • This article aims to study the dynamical behaviours of a two species model in which non-selective harvesting of a prey-predator system by using a reasonable catch-rate function instead of usual catch-per-unit-effort hypothesis is used. A system of two ordinary differential equations(ODE's) has been proposed and analyzed with the predator functional response to prey density is considered as Hassell-Varley type functional responses to study the dynamics of the system. Positivity and boundedness of the system are studied. We have discussed the existence of different equilibrium points and stability of the system at these equilibrium points. We also analysed the system undergoes a Hopf-bifurcation around interior equilibrium point for a various parametric values which has very significant ecological impacts in this work. Computer simulation are carried out to validate our analytical findings. The biological implications of analytical and numerical findings are discussed critically.

Efficacy of Bifidobacterium Tetragenous Viable Bacteria Tablets for Cancer Patients with Functional Constipation

  • Liu, Jin;Huang, Xin-En
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.23
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    • pp.10241-10244
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    • 2015
  • Objective: To investigate the efficacy and side effects of Bifidobacterium tetragenous viable bacteria tablets in treating cancer patients with functional constipation during chemotherapy. Methods: A consecutive cohort of 100 cancer patients with functional constipation were divided into two equal groups: patients in the experimental group were given Bifidobacterium tetragenous viable bacteria tablets combined with chemotherapy, while patients in the control group received chemotherapy alone. After 4 weeks, the efficacy and side effects in treating functional constipation were evaluated. Results: Constipation in 48 patients in experimental group was controlled (9 returned to normal), with a total response rate of 96%, and 1 patient reported diarrhea (2%). In contrast only 16 patients in the control group demonstrated improvement and 34 were still constipated after chemotherapy, with a response rate of 32%. The difference in response rate was statistically significant (P<0.05). Conclusion: This study suggested that Bifidobacterium tetragenous viable bacteria tablets are effective and safe in treating cancer patients with functional constipation during chemotherapy.

Effects of Gym Ball Stabilization Exercises on the Physical Functions of Elementary School Baseball Players

  • Kim, Se-Hun;Park, Jea-Cheol
    • The Journal of Korean Physical Therapy
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    • v.34 no.2
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    • pp.51-56
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    • 2022
  • Purpose: This study examined the effects of gym ball stabilization exercises on the physical functions of elementary school baseball players. Methods: The elementary school baseball players were assigned to an experimental group (n=21). The group performed gym ball stabilization exercises and the changes in the physical functions were measured using the visual response speed test, functional movements, physical balance ability, and pulmonary function. Results: The results of the visual response speed test showed changes in the time response speed. There was a significant change in the number of touches in 15 seconds in the upper arms and left and right legs (p<0.05) after 10 weeks. Also, there was a significant change in the reaction times of the left and right legs after 10 weeks (p<0.05). Further, there were significant differences in functional movements involving rotational stability and the total functional scores after 10 weeks (p<0.05). The player's body balance ability showed a significant difference after 10 weeks in the posterior-lateral and posterior-medial composite scores of the left and right legs (p<0.05). There was a significant change in the forced lung capacity and forced expiratory volume in 1 second after 10 weeks (p<0.05). Conclusion: These results show that the gym ball stabilization exercises effectively improved the visual response speed and functional movements, balance, and vital capacity of elementary school baseball players.

Comparisons of the Prognostic Predictors of Traumatic Brain Injury According to Admission Glasgow Coma Scale Scores Based on 1- and 6-month Assessments

  • Oh Hyun-Soo;Seo Wha-Sook;Lee Seul;Song Ho-Sook
    • Journal of Korean Academy of Nursing
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    • v.36 no.4
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    • pp.621-629
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    • 2006
  • Purpose. The purpose of this study was to identify the clinical variables that predict functional and cognitive recovery at 1- and 6-month in both severe and moderate/mild traumatic brain injury patients. Methods. The subjects of this study were 82 traumatically brain-injured patients who were admitted to a Neurological Intensive Care Unit at a university hospital. Potential prognostic factors included were age, motor and pupillary response, systolic blood pressure, heart rate, and the presence of intracranial hematoma at admission. Results. The significant predictors of functional disability in severe traumatic brain injury subjects were, age, systolic blood pressure, the presence of intracranial hematoma, motor response, and heart rate at admission. In moderate/mild traumatic brain injury patients, motor response, abnormal pupil reflex, and heart rate at admission were identified as significant predictors of functional disability. On the other hand, the significant predictors of cognitive ability for severe traumatic brain injury patients were motor response and the presence of intracranial hematoma at admission, whereas those for moderate/mild patients were motor response, pupil reflex, systolic blood pressure at admission, and age. Conclusions. The results of the present study indicate that the significant predictors of TBI differ according to TBI severity on admission, outcome type, and outcome measurement time. This can be meaningful to critical care nurses for a better understanding on the prediction of brain injury patients. On the other hand, the model used in the present study appeared to produce relatively low explicabilities for functional and cognitive recovery although a direct comparison of our results with those of others is difficult due to differences in outcome definition and validation methods. This implies that other clinical variables should be added to the model used in the present study to increase its predicting power for determining functional and cognitive outcomes.

Fuctional Response of Amblyseius longispinosus (Acari:Phytoseiidae) to Tetranychus urticae (Acari: Tetranychidae): Effects of Prey Density, Distribution, and Arena Size (긴털이리응애의 점박이응애에 대한 기능반응: 피식자 밀도, 분포 및 면적크기의 영향)

  • 김동순;이준호
    • Korean journal of applied entomology
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    • v.32 no.1
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    • pp.61-67
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    • 1993
  • Experiments were conducted to study the functional response of Amblyseius longispinosus Evans to egg densities (10-80) of Tetranychus urtica Koch under different egg distributions (clumped & uniform) and arena sizes (3, 9 & 16 $cm^2$). The searching success of A. longispinosus was affected by the spatial distribution and density of the prey but not by the arena size. there was a highly significant negative correlation (r=-0.85; p=0.0001) between predation amount and distances between preys. The predation response showed a type III functional response. The random predator equation satisfactorily described A. longispinosus predation. The search rate ranged from 0.1030 to 0.1504 under distribution of the prey while it ranged from 0.0546 to 0.276 under uniform distribution.

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A Stage-Structured Predator-Prey System with Time Delay and Beddington-DeAngelis Functional Response

  • Wang, Lingshu;Xu, Rui;Feng, Guanghui
    • Kyungpook Mathematical Journal
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    • v.49 no.4
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    • pp.605-618
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    • 2009
  • A stage-structured predator-prey system with time delay and Beddington-DeAngelis functional response is considered. By analyzing the corresponding characteristic equation, the local stability of a positive equilibrium is investigated. The existence of Hopf bifurcations is established. Formulae are derived to determine the direction of bifurcations and the stability of bifurcating periodic solutions by using the normal form theory and center manifold theorem. Numerical simulations are carried out to illustrate the theoretical results.

Complex Dynamic Behaviors of an Impulsively Controlled Predator-prey System with Watt-type Functional Response

  • Baek, Hunki
    • Kyungpook Mathematical Journal
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    • v.56 no.3
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    • pp.831-844
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    • 2016
  • In this paper, we consider a discrete predator-prey system with Watt-type functional response and impulsive controls. First, we find sufficient conditions for stability of a prey-free positive periodic solution of the system by using the Floquet theory and then prove the boundedness of the system. In addition, a condition for the permanence of the system is also obtained. Finally, we illustrate some numerical examples to substantiate our theoretical results, and display bifurcation diagrams and trajectories of some solutions of the system via numerical simulations, which show that impulsive controls can give rise to various kinds of dynamic behaviors.

Classical testing based on B-splines in functional linear models (함수형 선형모형에서의 B-스플라인에 기초한 검정)

  • Sohn, Jihoon;Lee, Eun Ryung
    • The Korean Journal of Applied Statistics
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    • v.32 no.4
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    • pp.607-618
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    • 2019
  • A new and interesting task in statistics is to effectively analyze functional data that frequently comes from advances in modern science and technology in areas such as meteorology and biomedical sciences. Functional linear regression with scalar response is a popular functional data analysis technique and it is often a common problem to determine a functional association if a functional predictor variable affects the scalar response in the models. Recently, Kong et al. (Journal of Nonparametric Statistics, 28, 813-838, 2016) established classical testing methods for this based on functional principal component analysis (of the functional predictor), that is, the resulting eigenfunctions (as a basis). However, the eigenbasis functions are not generally suitable for regression purpose because they are only concerned with the variability of the functional predictor, not the functional association of interest in testing problems. Additionally, eigenfunctions are to be estimated from data so that estimation errors might be involved in the performance of testing procedures. To circumvent these issues, we propose a testing method based on fixed basis such as B-splines and show that it works well via simulations. It is also illustrated via simulated and real data examples that the proposed testing method provides more effective and intuitive results due to the localization properties of B-splines.

Relationship between Functional Fitness and Break Response in Elderly Drivers: Comparison with Young Driver

  • Kim, Ga Eun;Choi, Ye Eun;Yang, Su Seong;Kim, Sun A;Bae, Young Sook
    • The Journal of Korean Physical Therapy
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    • v.30 no.5
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    • pp.187-192
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    • 2018
  • Purpose: This study compared the functional fitness and brake response of elderly and young drivers to confirm the correlation between the functional fitness and brake response. Methods: This study was a cross sectional observational design. Older drivers (>65age, n=21) and young adult drivers (20-40aged, n=20) were enrolled as subjects. The functional fitness of the subjects was measured using a senior fitness test consisting of a back scratch (BS), chair sit and reach (CSR), arm curl (AC), chair stand up (CSU), foot up and go (8-FUG), and 2-minute step (2-MS). The brake response used the virtual driving simulator to measure the brake reaction time (BRT) and braking distance (BD) according to the pedestrian protection and traffic signal compliance. Results: The older drivers had a lower BS (p<0.000), CSU (p=0.040), and 8-FUG (p=0.011) than the young adult drivers. BS and 8-FUG showed a significant positive correlation with the BRT and BD of pedestrian protection and traffic signal compliance. CSU showed a significant negative correlation with the BRT of pedestrian protection and traffic signal compliance. Conclusion: These findings suggest that the flexibility of the upper extremity, lower extremity strength, and agility are strongly correlated with the driving performance of elderly drivers.

Activity-dependent plasticity in skeletal muscle (골격근의 활동 의존적 가소성)

  • Kim, Sik-Hyun
    • PNF and Movement
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    • v.6 no.1
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    • pp.41-51
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    • 2008
  • Purpose : This paper reviews evidence supporting adaptive plasticity in skeletal muscle fibers induced by various exercise training and neuromuscular activity. Result : Skeletal muscle fiber demonstrates a remarkable adaptability and can adjust its physiologic and contractile makeup in response to alterations in functional demands. This adaptive plasticity results from the ability of muscle fibers to adjust their molecular, functional, and contractile properties in response to altered physiological demands, such as changes in exercise patterns and mechanical loading. The process of activity-dependent plasticity in skeletal muscle involves a multitude of signalling mechanisms initiating replication of specific genetic sequences, enabling subsequent translation of the genetic message and ultimately generating a series of myosin heavy chain isoform. Conclusions : Knowledge of the mechanisms and interaction of activity-dependent adaptive pathways in skeletal muscle is important for our understanding of the synthesis of muscle myosin protein, maintenance of metabolic and functional capacity with physical activity, and therapeutic intervention for functional improvement.

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