• 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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    • 제40권5_6호
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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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    • 제15권23호
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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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    • 제34권2호
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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
    • 대한간호학회지
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    • 제36권4호
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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.

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

  • 김동순;이준호
    • 한국응용곤충학회지
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    • 제32권1호
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    • pp.61-67
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    • 1993
  • 점박이응애(Tetranychus urncae)의 알밀도(10~80), 공간분포〈집중 빛 균일분포) 및 서석면적크기 (3, 9, 16 $cm^2$)에 따른 긴털이리응애(Amblyseius longispinosus)의 가능반응을 연구하여 다음과 같은 결과를 얻었다. 긴털이리웅애의 점박이응애 발견효율은 밀도와 공간분포의 영향을 받았으나, 면적의 영향은 없었다. 포식량과 피식자간의 거리와는 매우 높은 역상관관계를 보였다(r=강.85; p=0.0001). 포식반응은 제2형의 기능반응을 보였다. 긴털이리응애의 기능반응은 random predator equation으로 잘 설명되었으며, 탐색률은 피식자의 집중분포하에서 반응면적에 따라 0.1030 - 0.1504였고 균일분포하에서는 0.0546~0.0276였다.

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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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    • 제49권4호
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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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    • 제56권3호
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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.

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

  • 손지훈;이은령
    • 응용통계연구
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    • 제32권4호
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    • pp.607-618
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    • 2019
  • 현대 과학기술의 발전으로 인해 함수 형태의 자료(functional data)는 기상학, 생물의학과 다양한 분야에서 발생하고 있으며 이러한 자료를 분석하는 것은 새롭고 흥미로운 통계과제라 할 수 있다. 스칼라 반응변수를 가진 함수형 선형회귀 모형(functional linear regression models with scalar response)은 널리 사용되는 함수형 자료 분석기법 중의 하나라 할 수 있고 이 회귀 모형에서 함수형 자료 (설명변수) 가 스칼라 반응변수에 영향력을 미치는지 검정하는 것은 중요한 문제라 할 수 있다. 최근, Kong 등은 함수형 주성분분석(functional principle component analysis)에 의한 차원 축소, 즉, 함수형 주성분분석 결과 얻어지는 고유함수(eigenfunctions)를 활용한 검정방법을 제안했다. 하지만, 그 고유함수들은 검정문제에서 관심사인 함수형 설명변수와 스칼라 반응변수의 연관성이 아니라 함수형 설명변수의 변동만을 고려하기 때문에 회귀문제에 사용하기에 일반적으로 적합한 기저가 아니다. 게다가, 자료로부터 추정하여야 하기 때문에 이 불필요한 추정오차가 검정 절차 성능에 포함될 가능성이 있다. 이러한 단점을 피하기 위해 본 논문에서는 기존의 고유기저함수가 아닌 고정기저(fixed basis)인 B-스플라인(B-splines) 함수를 활용한 검정 방법을 제안한고 모의실험을 통해 검정방법이 잘 작동한다는 것을 보여준다. 또한, 제안한 검정 방법은 B-스플라인의 국소화 성질 때문에 때론 효율적이고 직관적인 결과를 제공하는데 이를 모의실험과 실증자료 분석을 통해 보여줄 것이다.

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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    • 제30권5호
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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.

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

  • 김식현
    • PNF and Movement
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    • 제6권1호
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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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