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1.
BMC Complement Med Ther ; 24(1): 203, 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38790041

RESUMEN

INTRODUCTION: Globally medical students reported high level of stress sensitivity, stress intensity and depression or anxiety. Yoga is proven to be a one of the most effective anxiolytic tools. The current study specifically designed to investigate the effect of yoga intervention on the level of stress, depression, and anxiety of medical student at the University of Pécs. METHODS: Twenty-eight medical students from the University of Pécs, with an average age of 23.54 ± 4.36 years and a BMI of 22.42 ± 3.42 kg/m2, participated in a 10-week yoga intervention. In the current study, the DASS-21 was employed to gather information on stress, depression, and anxiety, while self-reported health and quality of life were assessed using the WHOQOL-BREF Questionnaire. The Shapiro-Wilk test was employed to examine the distribution of the data. The choice between the paired sampled T-test and the Wilcoxon signed test was determined based on the distribution of the data. RESULTS: The intervention group exhibited a mean and standard deviation of depression pre- and post-yoga 10.14 ± 10.60 and 7.21 ± 8.56, similarly the values for anxiety were 8.57 ± 10.09 and 5.51 ± 7.42, and for stress values were 12.79 ± 10.73 and 9.64 ± 9.71 respectively. Notably, this outcome attribute to a significant in decreased depression (p = 0.019), anxiety (p = 0.049) among the participants. CONCLUSIONS: Introduction of Yoga Intervention significantly decreased in levels of depression and anxiety. By this current study we were able to confirm the necessity of Yoga Intervention with our primary survey.


Asunto(s)
Ansiedad , Depresión , Estrés Psicológico , Estudiantes de Medicina , Yoga , Humanos , Estudiantes de Medicina/psicología , Proyectos Piloto , Masculino , Depresión/terapia , Adulto Joven , Adulto , Femenino , Ansiedad/terapia , Estrés Psicológico/terapia , Calidad de Vida , Encuestas y Cuestionarios
2.
Heliyon ; 9(9): e20064, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809477

RESUMEN

We investigate how simple physical interactions can generate remarkable diversity in the life history of social agents using data of social wasps, yielding complex scalable task partitioning. We built and analyzed a computational model to investigate how diverse task allocation patterns found in nature can emerge from the same behavioral blueprint. Self-organizing mechanisms of interwoven behavioral feedback loops, task-dependent time delays and simple material flows between interacting individuals yield an emergent homeostatic self-regulation while keeping the global colony performance scalable. Task allocation mechanisms based on implicitly honest signaling via material flows are not only very robust but are also highly evolvable due to their simplicity and reliability. We find that task partitioning has evolved to be scalable and adaptable to life history traits, such as expected colony size or temporal bottlenecks in the available workforce or materials. By tuning solely the total number of agents and a social connectivity-related parameter in the model, our simulations yield the whole range of emergent patterns in task allocation and task fidelity akin to observed field data. Our model suggests that the material exchange ("common stomach mechanism") found in many paper wasps provides a common functional "core" across these genera, which not only provides self-regulation of the colony, but also provides a scalable mechanism allowing natural selection to yield complex social integration in larger colonies over the course of their evolutionary trajectory.

3.
Sci Rep ; 13(1): 14238, 2023 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-37648819

RESUMEN

The study aimed to reveal physical exercise conditions and catecholamine response-dependent differences while an individual experiences a flow state (FS) following noncompetitive and competitive running drills. Urine laboratory catecholamine levels were measured using a standard clinical method during pre- and post-physical exercises. The noncompetitive task involved intermittent running drills, from an absolute beginning up through exhaustion. Initially, the drill is performed individually then later competing alongside other runners. Twenty-two males (mean age: 40.27; SD: 5.4; min-max: 31-49 years) were selected in accordance to the following criterion: healthy status without using medication, routine forms of training (running, cycling or swimming) ideally performed with regularity, at least three times per week, 45 min per session. During the noncompetitive task, a high FS experience was associated with a low level of catecholamines, (noradrenaline and adrenaline) while in parallel, the high FS was associated with a low concentration of homovallinic acid. During competitive conditions, the FS-related catecholamine level changes have not yet been found. In conclusion, the low concentration of the circulating catecholamines supports the transient hypofrontality hypothesis regarding the FS experiences. Furthermore, synchronized noradrenaline and adrenaline neurosecretion play an essential role in the manifestation and the prolongation of FS in noncompetitive exercise conditions.


Asunto(s)
Carrera , Masculino , Humanos , Adulto , Epinefrina , Norepinefrina , Catecolaminas , Natación
4.
Front Behav Neurosci ; 16: 763220, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35558438

RESUMEN

The aim of this study was to reveal whether increased reward dependence (RD) plays a role in the catecholamine neurotransmitter release and testosterone hormone regulation during physical activities among healthy trained participants. Twenty-two male participants (mean age: 40.27 ± 5.4 years) participated in this study. Two conditions were constructed, namely, a noncompetitive and a competitive running task (RT), which were separated by a 2-week interval. Urine and blood samples were collected prior to and following the running tasks. Noradrenaline (NA), adrenaline (A), dopamine (D), and their metabolites, vanillylmandelic acid (VMA) and homovanillic acid (HVA), were measured from urine, while testosterone levels were analyzed from blood samples. RD was assessed using the Cloninger's Personality Inventory (PI). Mental health was evaluated using the WHO Well-Being, Beck Depression, and Perceived Life Stress Questionnaires. According to our findings, levels of NA, A, D, VMA, and testosterone released underwent an increase following physical exertion, independently from the competitive condition of the RT, while HVA levels experienced a decrease. However, we found that testosterone levels showed a significantly lower tendency to elevate in the competitive RT, compared with the noncompetitive condition (p = 0.02). In contrast, HVA values were higher in the competitive compared with the noncompetitive condition (p = 0.031), both before and after the exercise. Considering the factor RD, in noncompetitive RT, its higher values were associated with elevated NA levels (p = 0.007); however, this correlation could not be detected during the competitive condition (p = 0.233). Among male runners, the NA and testosterone levels could be predicted to the degree of RD by analyzing competitive and noncompetitive physical exercises.

5.
PLoS One ; 14(2): e0212147, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30726299

RESUMEN

[This corrects the article DOI: 10.1371/journal.pone.0188004.].

6.
Proc Natl Acad Sci U S A ; 115(52): 13180-13185, 2018 12 26.
Artículo en Inglés | MEDLINE | ID: mdl-30530662

RESUMEN

Homeostatic self-regulation is a fundamental aspect of open dissipative systems. Integral feedback has been found to be important for homeostatic control on both the cellular and molecular levels of biological organization and in engineered systems. Analyzing the task allocation mechanisms of three insect societies, we identified a model of integral control residing at colony level. We characterized a general functional core mechanism, called the "common stomach," where a crucial shared substance for colony function self-regulates its own quantity via reallocating the colony's workforce, which collects and uses this substance. The central component in a redundant feedback network is the saturation level of this substance in the colony. An interaction network of positive and negative feedback loops ensures the homeostatic state of this substance and the workforce involved in processing this substance. Extensive sensitivity and stability analyses of the core model revealed that the system is very resilient against perturbations and compensates for specific types of stress that real colonies face in their ecosystems. The core regulation system is highly scalable, and due to its buffer function, it can filter noise and find a new equilibrium quickly after environmental (supply) or colony-state (demand) changes. The common stomach regulation system is an example of convergent evolution among the three different societies, and we predict that similar integral control regulation mechanisms have evolved frequently within natural complex systems.


Asunto(s)
Retroalimentación , Homeostasis , Insectos/fisiología , Modelos Biológicos , Conducta Social , Estómago/fisiología , Análisis y Desempeño de Tareas , Animales , Conducta Animal/fisiología
7.
PLoS One ; 12(11): e0188004, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29161278

RESUMEN

We propose a new regulation mechanism based on the idea of the "common stomach" to explain several aspects of the resilience and homeostatic regulation of honeybee colonies. This mechanism exploits shared pools of substances (pollen, nectar, workers, brood) that modulate recruitment, abandonment and allocation patterns at the colony-level and enable bees to perform several survival strategies to cope with difficult circumstances: Lack of proteins leads to reduced feeding of young brood, to early capping of old brood and to regaining of already spent proteins through brood cannibalism. We modeled this system by linear interaction terms and mass-action law. To test the predictive power of the model of this regulatory mechanism we compared our model predictions to experimental data of several studies. These comparisons show that the proposed regulation mechanism can explain a variety of colony level behaviors. Detailed analysis of the model revealed that these mechanisms could explain the resilience, stability and self-regulation observed in honeybee colonies. We found that manipulation of material flow and applying sudden perturbations to colony stocks are quickly compensated by a resulting counter-acting shift in task selection. Selective analysis of feedback loops allowed us to discriminate the importance of different feedback loops in self-regulation of honeybee colonies. We stress that a network of simple proximate mechanisms can explain significant colony-level abilities that can also be seen as ultimate reasoning of the evolutionary trajectory of honeybees.


Asunto(s)
Abejas/fisiología , Homeostasis/fisiología , Conducta Social , Estómago/fisiología , Animales , Mucosa Gástrica/metabolismo , Larva/metabolismo , Larva/fisiología , Néctar de las Plantas/metabolismo , Polen/metabolismo
8.
PLoS One ; 11(11): e0167041, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27861633

RESUMEN

Simple regulatory mechanisms based on the idea of the saturable 'common stomach' can control the regulation of construction behavior and colony-level responses to environmental perturbations in Metapolybia wasp societies. We mapped the different task groups to mutual inductance electrical circuits and used Kirchoff's basic voltage laws to build a model that uses master equations from physics, yet is able to provide strong predictions for this complex biological phenomenon. Similar to real colonies, independently of the initial conditions, the system shortly sets into an equilibrium, which provides optimal task allocation for a steady construction, depending on the influx of accessible water. The system is very flexible and in the case of perturbations, it reallocates its workforce and adapts to the new situation with different equilibrium levels. Similar to the finding of field studies, decreasing any task groups caused decrease of construction; increasing or decreasing water inflow stimulated or reduced the work of other task groups while triggering compensatory behavior in water foragers. We also showed that only well connected circuits are able to produce adequate construction and this agrees with the finding that this type of task partitioning only exists in larger colonies. Studying the buffer properties of the common stomach and its effect on the foragers revealed that it provides stronger negative feedback to the water foragers, while the connection between the pulp foragers and the common stomach has a strong fixed-point attractor, as evidenced by the dissipative trajectory.


Asunto(s)
Conducta Animal , Modelos Teóricos , Conducta Social , Avispas , Algoritmos , Animales , Avispas/fisiología
9.
PLoS One ; 11(1): e0145560, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26751076

RESUMEN

Evolutionary benefits of task fidelity and improving information acquisition via multiple transfers of materials between individuals in a task partitioned system have been shown before, but in this paper we provide a mechanistic explanation of these phenomena. Using a simple mathematical model describing the individual interactions of the wasps, we explain the functioning of the common stomach, an information center, which governs construction behavior and task change. Our central hypothesis is a symmetry between foragers who deposit water and foragers who withdraw water into and out of the common stomach. We combine this with a trade-off between acceptance and resistance to water transfer. We ultimately derive a mathematical function that relates the number of interactions that foragers complete with common stomach wasps during a foraging cycle. We use field data and additional model assumptions to calculate values of our model parameters, and we use these to explain why the fullness of the common stomach stabilizes just below 50 percent, why the average number of successful interactions between foragers and the wasps forming the common stomach is between 5 and 7, and why there is a variation in this number of interactions over time. Our explanation is that our proposed water exchange mechanism places natural bounds on the number of successful interactions possible, water exchange is set to optimize mediation of water through the common stomach, and the chance that foragers abort their task prematurely is very low.


Asunto(s)
Conducta Cooperativa , Modelos Estadísticos , Avispas/fisiología , Agua/metabolismo , Animales , Transporte Biológico , Simulación por Computador , Modelos Biológicos
10.
J Theor Biol ; 389: 274-86, 2016 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-26576492

RESUMEN

Simple regulatory mechanisms based on the idea of the saturable 'common stomach' can control the regulation of protein foraging and protein allocation in honeybee colonies and colony-level responses to environmental changes. To study the economic benefits of pollen and nectar foraging strategies of honeybees to both plants and honeybees under different environmental conditions, a model was developed and analyzed. Reallocation of the foraging workforce according to the quality and availability of resources (an 'adaptive' strategy used by honeybees) is not only a successful strategy for the bees but also for plants, because intensified pollen foraging after rain periods (when nectar quality is low) compensates a major fraction of the pollination flights lost during the rain. The 'adaptive' strategy performed better than the'fixed' (steady, minimalistic, and non-adaptive foraging without feedback) or the 'proactive' (stockpiling in anticipation of rain) strategies in brood survival and or in nectar/sugar economics. The time pattern of rain periods has profound effect on the supply-and-demand of proteins. A tropical rain pattern leads to a shortage of the influx of pollen and nectar, but it has a less profound impact on brood mortality than a typical continental rainfall pattern. Allocating more bees for pollen foraging has a detrimental effect on the nectar stores, therefore while saving larvae from starvation the 'proactive' strategy could fail to collect enough nectar for surviving winter.


Asunto(s)
Abejas/fisiología , Conducta Animal/fisiología , Conducta Cooperativa , Conducta Alimentaria/fisiología , Animales , Ambiente , Femenino , Homeostasis , Larva , Masculino , Néctar de las Plantas , Polen/fisiología , Polinización/fisiología , Lluvia , Estaciones del Año , Clima Tropical
11.
Sci Total Environ ; 538: 279-87, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26311583

RESUMEN

Potential long-term (~7months) sub-lethal impacts of soil-applied low levels of Roundup herbicide formulation were investigated in a greenhouse environment using the vegetative clones of succulent non-crop plant model, Bryophyllum pinnatum (Lam.) Oken. An eleven day LC50 (concentration that killed 50% of the plants) was found to be 6.25% (~1.25mg glyphosate/mL and 1.25mg pelargonic acid/mL combined), and complete mortality occurred at 12.5%, of the field application rate (i.e., ~20mg glyphosate/mL and 20mg pelargonic acid/mL as active ingredients). While sub-lethal Roundup (1-5%) exposures led to hormesis-characterized by a significant increase in biomass and vegetative reproduction, higher concentrations (≥6.25%) were toxic. A significant interaction between Roundup concentrations and leaf biomass was found to influence the F1 plantlets' biomass. Biomass asymmetry generally increased with increasing Roundup concentrations, indicating that plants were more stressed at higher Roundup treatments but within the low-dose regime (≤5% of the as-supplied formulation). While leaf apex region demonstrated higher reproduction with lower biomass increase, leaf basal area showed lower reproduction with greater biomass increase, in plantlets. The results suggest long-term exposures to drifted low levels of Roundup in soil may promote biomass and reproduction in B. pinnatum.


Asunto(s)
Ácidos Grasos/toxicidad , Glicina/análogos & derivados , Herbicidas/toxicidad , Kalanchoe/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Glicina/toxicidad , Reproducción/efectos de los fármacos , Glifosato
12.
Res Q Exerc Sport ; 86 Suppl 1: S13-20, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-26054951

RESUMEN

PURPOSE: The purpose of this study was to cross-validate FITNESSGRAM® aerobic and body composition standards in a representative sample of Hungarian youth. METHOD: A nationally representative sample (N = 405) of Hungarian adolescents from the Hungarian National Youth Fitness Study (ages 12-18.9 years) participated in an aerobic capacity assessment via treadmill test to maximum to determine peak oxygen consumption (VO2peak) and a bioelectrical impedance assessment to estimate percent body fat (%BF). Additionally, metabolic syndrome status was assessed via finger-stick blood sample. Youth were categorized into Healthy Fitness Zone (HFZ) and Needs Improvement (NI) groups based on Fitnessgram standards. Prevalence of metabolic syndrome was calculated and logistic regression was used to estimate odds of metabolic syndrome. RESULTS: Hungarian youth were generally fit with a low prevalence of metabolic syndrome. Approximately 69% to 77% of boys and 55% to 57% of girls were classified into the HFZ based on %BF and VO2peak. Youth in the NI health risk zones for VO2peak and %BF were 4 times to 5 and 2 times to 3 times more likely to have metabolic syndrome than children in the lower-risk groups, respectively. CONCLUSIONS: Fitnessgram standards for aerobic capacity and body composition were associated with metabolic syndrome status, though odds ratios were larger for VO2peak than for %BF and varied by sex. Even though these standards were developed in U.S. youth, they can be applied in Hungary and still provide a criterion-referenced indication of fitness.


Asunto(s)
Prueba de Esfuerzo , Aptitud Física , Adolescente , Distribución de la Grasa Corporal , Niño , Femenino , Humanos , Hungría/epidemiología , Masculino , Síndrome Metabólico/epidemiología , Obesidad/epidemiología , Consumo de Oxígeno , Prevalencia , Factores de Riesgo , Instituciones Académicas
13.
Res Q Exerc Sport ; 86 Suppl 1: S29-36, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-26054953

RESUMEN

PURPOSE: The purpose of this study was to examine age- and sex-related variation in handgrip strength and to determine reference values for the Hungarian population. METHOD: A sample of 1,086 Hungary youth (aged 11-18 years old; 654 boys and 432 girls) completed a handgrip strength assessment using a handheld dynamometer. Quantile regression was used to compute separate models for boys and girls and included a linear, cubic, and quadratic term for age to account for nonlinear patterns. These terms were tested for statistical significance using the Wald statistical test with p < .05. Age- and sex-specific centiles were generated and the 50th percentile was used to describe the overall patterns in handgrip strength. RESULTS: The linear, cubic, and quadratic terms for age fitted the data well for boys (p < .05), while both linear and quadratic terms for age were statistically significant for girls (p < .05). The 50th percentile values resulted in 21.4 kg, 21.7 kg, 25.0 kg, 30.0 kg, 35.4 kg, 40.0 kg, 42.6 kg, and 42.0 kg for boys aged 11 to 18 years old, respectively. The same percentile resulted in 20.0 kg, 19.5 kg, 19.6 kg, 20.3 kg, 21.6 kg, 23.5 kg, 26.1 kg, and 29.2 kg for girls aged 11 to 18 years old, respectively. CONCLUSIONS: Muscle strength as determined by handgrip has distinct age-related patterns in boys and girls. We have accounted for biological age differences and developed norm-referenced values that can be used to interpret handgrip assessment scores obtained from school-aged children in Hungary.


Asunto(s)
Fuerza de la Mano , Adolescente , Factores de Edad , Niño , Femenino , Humanos , Hungría , Masculino , Dinamómetro de Fuerza Muscular , Valores de Referencia , Instituciones Académicas , Factores Sexuales
14.
Res Q Exerc Sport ; 86 Suppl 1: S3-S12, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-26054954

RESUMEN

The 2012 Public Act on Education in Hungary made daily physical education (PE) a mandatory part of the school day starting in the 2012-2013 school year. This directive was linked to a significant reorganization of the Hungarian education system including a new National Core Curriculum that regulates the objectives and contents of PE. The Hungarian School Sport Federation (HSSF) recognized the opportunity and created the Strategic Actions for Health-Enhancing Physical Education or Testnevelés az Egészségfejlesztésben Stratégiai Intézkedések (TESI) project. Physical fitness assessments have been a traditional part of the Hungarian PE program; however, the TESI plan called for the use of a new health-related battery and assessment system to usher in a new era of fitness education in the country. The HSSF enlisted the Cooper Institute to assist in building an infrastructure for full deployment of a national student fitness assessment program based on the FITNESSGRAM® in Hungarian schools. The result is a new software-supported test battery, namely the Hungarian National Student Fitness Test (NETFIT), which uses health-related, criterion-referenced youth fitness standards. The NETFIT system now serves as a compulsory fitness assessment for all Hungarian schools. This article details the development process for the test battery and summarizes the aims and methods of the Hungarian National Youth Fitness Study.


Asunto(s)
Prueba de Esfuerzo , Aptitud Física , Adolescente , Niño , Femenino , Humanos , Hungría , Masculino , Educación y Entrenamiento Físico , Evaluación de Programas y Proyectos de Salud , Instituciones Académicas , Adulto Joven
15.
Res Q Exerc Sport ; 86 Suppl 1: S58-65, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-26054957

RESUMEN

PURPOSE: The purpose of this study was to test the convergent validity of Omron 306 using Biospace InBody 720. METHOD: A total of 267 participants (145 boys; aged 10.4-17.9 years) completed testing during a single session. Each measure provided percent body fat (%BF), while the InBody 720 included fat-free mass (FFM). The validity was examined using the Pearson correlation. Limits of agreement (LOA) and multiple linear regression were also used to determine the impact of both age and FFM on the associations between the 2 measures. RESULTS: The 2 measures of %BF were correlated by .63 (p < .001) in boys and .89 (p < .001) in girls. The mean difference (i.e., InBody - Omron) for %BF in boys was - 4.7% with a lower LOA of - 20.5% and upper LOA of 11.2%. The same comparison for girls resulted in a difference of 3.0% with a lower LOA of - 10% and upper LOA of 4%. Examination of the residuals obtained from multiple linear regression indicated that FFM was the only statistically significant predictor of differences in boys (ßFFM = - 0.25 ± 0.08%, p = .001). There were no significant associations for girls. CONCLUSIONS: Findings indicate that estimates of %BF obtained from Omron in boys exceed estimates from InBody 720. Disagreement was evident in younger boys with lower levels of FFM. Girls' %BF was closer between the 2 bioelectrical impedance analyzer measures (less residual) with age and FFM not explaining the disagreement. Overall, the 2 measures were not equivalent.


Asunto(s)
Distribución de la Grasa Corporal , Impedancia Eléctrica , Adolescente , Factores de Edad , Niño , Femenino , Humanos , Hungría , Masculino , Aptitud Física , Reproducibilidad de los Resultados , Instituciones Académicas , Factores Sexuales
16.
Res Q Exerc Sport ; 86 Suppl 1: S74-81, 2015 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-26054959

RESUMEN

PURPOSE: The purpose of this study was to create a physical education (PE) attitude scale and examine how it is associated with aerobic capacity (AC). METHOD: Participants (n = 961, aged 15-20 years) were randomly selected from 26 Hungarian high schools. AC was estimated from performance on the Progressive Aerobic Cardiovascular and Endurance Run test, and the attitude scale had 31 items measured on a Likert scale that ranged from 1 to 5. Principal component analysis was used to examine the structure of the questionnaire while several 2-way analyses of variance and multiple linear regression (MLR) were computed to examine trends in AC and test the association between component scores obtained from the attitude scale and AC, respectively. RESULTS: Five components were identified: health orientation in PE (C1), avoid failure in PE (C2), success orientation in PE (C3), attitude toward physical activity (C4), and cooperation and social experience in PE (C5). There was a statistically significant main effect for sex on C3 (p < .05), C4 (p < .001), and C5 (p < .05) indicating that boys' scores were higher than girls. The Sex × Age interaction was also statistically significant (p < .05) and follow-up comparisons revealed sex differences in C5 for 15-year-old participants. Girls showed statistically significant higher values than boys in C5 at the age of 16 years. MLR results revealed that component scores were significantly associated with AC (p < .05). Statistically significant predictors included C1, C2, C3, and C4 for boys and C2 and C4 for girls. CONCLUSION: The 5-component scale seems to be suitable for measuring students' attitudes toward PE. The design of the study does not allow for direct associations between attitudes and AC but suggests that these 2 might be related.


Asunto(s)
Actitud , Fenómenos Fisiológicos Cardiovasculares , Educación y Entrenamiento Físico , Aptitud Física , Estudiantes/psicología , Adolescente , Factores de Edad , Femenino , Humanos , Hungría , Masculino , Consumo de Oxígeno , Instituciones Académicas , Factores Sexuales , Encuestas y Cuestionarios , Adulto Joven
17.
PLoS One ; 9(12): e114611, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25493558

RESUMEN

We develop a model to produce plausible patterns of task partitioning in the ponerine ant Ectatomma ruidum based on the availability of living prey and prey corpses. The model is based on the organizational capabilities of a "common stomach" through which the colony utilizes the availability of a natural (food) substance as a major communication channel to regulate the income and expenditure of the very same substance. This communication channel has also a central role in regulating task partitioning of collective hunting behavior in a supply&demand-driven manner. Our model shows that task partitioning of the collective hunting behavior in E. ruidum can be explained by regulation due to a common stomach system. The saturation of the common stomach provides accessible information to individual ants so that they can adjust their hunting behavior accordingly by engaging in or by abandoning from stinging or transporting tasks. The common stomach is able to establish and to keep stabilized an effective mix of workforce to exploit the prey population and to transport food into the nest. This system is also able to react to external perturbations in a de-centralized homeostatic way, such as to changes in the prey density or to accumulation of food in the nest. In case of stable conditions the system develops towards an equilibrium concerning colony size and prey density. Our model shows that organization of work through a common stomach system can allow Ectatomma ruidum to collectively forage for food in a robust, reactive and reliable way. The model is compared to previously published models that followed a different modeling approach. Based on our model analysis we also suggest a series of experiments for which our model gives plausible predictions. These predictions are used to formulate a set of testable hypotheses that should be investigated empirically in future experimentation.


Asunto(s)
Hormigas/fisiología , Conducta Alimentaria/fisiología , Modelos Biológicos , Conducta Predatoria/fisiología , Conducta Social , Animales
18.
J Sports Sci Med ; 13(1): 200-10, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24570625

RESUMEN

THE AIMS OF THIS STUDY WERE: i) to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase) in each lap of 200m breaststroke, ii) quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1(st) to the 3(rd) lap. SR increased on the 4(th) lap (35.91 ± 2.99 stroke·min(-1)). Peak blood lactate was 13.02 ± 1.72 mmol·l(-1) three minutes after the maximal trial. The EMG average rectified value (ARV) increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1(st) lap and for biceps brachii, deltoid anterior and triceps brachii in the 4(th) lap. The mean frequency of the power spectral density (MNF) decreased at the 4(th) lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2(nd) lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state. Key PointsFatigue in the upper limbs occurs in different way as it described by 100m swimming events.Neuromuscular fatigue was estimated by analyzing the physiological changes (high blood lactate concentrations), biomechanical changes in the swimming stroke characteristics (decreased in swimming velocity), and by the changes in the EMG amplitude and frequency parameters at the end of the swimming bout.The amplitude signal of EMG provided by the ARV demonstrated an increase at the end with the respect to the beginning for all muscles under study, excepted for the muscle deltoid anterior.The mean frequency (MNF) in our study decrease at the end of the swimming in the 4(th) lap relative to the 1(st) lap for all muscles under observation, along the 200m breaststroke.

19.
J Hum Kinet ; 36: 17-26, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23717351

RESUMEN

The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.

20.
Bull Math Biol ; 75(7): 1181-206, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23666484

RESUMEN

Task allocation, and task switching have an important effect on the efficiency of distributed, locally controlled systems such as social insect colonies. Both efficiency and workload distribution are global features of the system which are not directly accessible to workers and can only be sampled locally by an individual in a distributed system. To investigate how the cost of task switching affects global performance we use social wasp societies as a metaphor to construct a simple model system with four interconnected tasks. Our goal is not the accurate description of the behavior of a given species, but to seek general conclusions on the effect of noise and time delay on a behavior that is partitioned into subtasks. In our model a nest structure needs to be constructed by the cooperation of individuals that carry out different tasks: builders, pulp and water foragers, and individuals storing water. We report a simulation study based on a model using delay-differential equations to analyze the trade-off between task switching costs and keeping a high degree of adaptivity in a dynamic, noisy environment. Combining the methods of time-delayed equations and stochastic processes we are able to represent the influence of swarm size and task switching sensitivity. We find that the system is stable for reasonable choices of parameters but shows oscillations for extreme choices of parameters and we find that the system is resilient to perturbations. We identify a trade-off between reaching equilibria of high performance and having short transients.


Asunto(s)
Modelos Biológicos , Conducta Social , Animales , Conducta Animal , Conceptos Matemáticos , Factores de Tiempo , Avispas/fisiología
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