Functional response and population dynamics for fighting predator, based on activity distribution

The classical Holling type II functional response, describing the per capita predation as function of prey density, was modified by Beddington and DeAngelis to include interference of predators that increases with predator density and decreases the number of killed prey. In the present paper we further generalize the Beddington–DeAngelis functional response, considering that all predator activities (searching and handling prey, fight and recovery) have time duration, the probabilities of predator activities depend on the encounter probabilities, and hence on the prey and predator abundance, too. Under these conditions, the aim of the study is to introduce a functional response for fighting predator and analyse the corresponding dynamics, when predator-predator-prey encounters also occur. From this general approach, the Holling type functional responses can be also obtained as particular cases. In terms of the activity distribution, we give biologically interpretable sufficient conditions for stable coexistence. We consider two-individual (predator-prey) and three-individual (predator-predator-prey) encounters. In the three-individual encounter model there is a relatively higher fighting rate and a lower killing rate. Using numerical simulation, we surprisingly found that when the intrinsic prey growth rate and the conversion rate are small enough, the equilibrium predator abundance is higher in the three-individual encounter case. The above means that, when the equilibrium abundance of the predator is small, coexistence appears first in the three-individual encounter model

The relationship between organizational structure and market orientation: An empirical aproach

This study analyzes different antecedents of market orientation and goes deeply into the analysis of the relationship between organizational structure and market orientation. The data for the empirical research comes from a sample of small firms belonging to the industrial sector in the geographical area of an economy of the south of Europe - the Andalusian economy. The study includes 85 correctly-completed questionnaires. The results confirm the effect of formalization, integration and centralization on the firms' marketing orientation, but they do not allow it to be stated that there is a relationship between firms' marketing orientation and complexity. The implication for management is the need to check the organizational structures in order for them not to slow down the introduction of market orientation

Optimal Forager Against Ideal Free Distributed Prey

The introduced dispersal-foraging game is a combination of prey habi2 tat selection among two patch types and optimal foraging approaches. Prey’s patch 3 preference and forager behavior determine the prey’s survival rate. The forager’s 4 energy gain depends on local prey density in both types of exhaustible patches and 5 on leaving time. 6 We introduce two game solution concepts. The static solution combines the ideal 7 free distribution of the prey with optimal foraging theory. The dynamical solution 8 is given by a game dynamics, describing the behavioral changes of prey and forager. 9 We show that (a) each stable equilibrium dynamical solution is always a static 10 solution, but not conversely; (b) at an equilibrium dynamical solution, the forager 11 can stabilize prey mixed patch use strategy in cases where ideal free distribution 12 theory predicts that prey will use only one patch type; (c) when the equilibrium 13 dynamical solution is unstable at fixed prey density, stable behavior cycles occur 14 where neither forager nor prey keep a fixed behavior

Equilibrium control of nonlinear verticum-type systems, applied to integrated pest control

Linear verticum-type control and observation systems have been introduced for modelling certain industrial systems, consisting of subsystems, vertically connected by certain state variables. Recently the concept of verticum-type observation systems and the corresponding observability condition have been extended by the authors to the nonlinear case. In the present paper the general concept of a nonlinear verticum-type control system is introduced, and a sufficient condition for local controllability to equilibrium is obtained. In addition to a usual linearization, the basic idea is a decomposition of the control of the whole system into the control of the subsystems. Starting from the integrated pest control model of Rafikov and Limeira (2012) and Rafikov et al. (2012), a nonlinear verticum-type model has been set up an equilibrium control is obtained. Furthermore, a corresponding bioeconomical problem is solved minimizing the total cost of integrated pest control (combining chemical control with a biological one)

Grafted Sepiolites for the Removal of Pharmaceuticals in Water Treatment

The increased detection of pharmaceuticals in finished drinking water has become a growing cause of concern in recent years. The removal of atenolol, ranitidine, and carbamazepine by sepiolite, following functionalization of its surface by organosilane grafting, constituted the subject of this investigation. Silylated surfaces include octyl, γ-aminopropyl, 3-chloropropyl, and triphenyl moieties. The sorption of atenolol and ranitidine was higher on sepiolite functionalized with 3-chloropropyl, while carbamazepine showed a higher sorption on sepiolite with triphenyl groups. Filtration experiments of both ranitidine and carbamazepine on octyl- and triphenyl-sepiolite, respectively, showed a higher retention of ranitidine in comparison to carbamazepine, in spite of the fact that the number of sorption sites was lower due to its higher binding rate.Ministerio de Educación y Cultura CTM2013-42306-R, CTM2016-77168-

Confiabilidad entre instrumentos (T-Force y Myotest) en la valoración de la fuerza

The purpose of this study was to determine the inter-machine reliability of two devices routinely used to measure variables in sports performance: the linear position measuring device (LPM, isoinertial dynamometer T-Force) and the (AC) 3-D accelerometer (Myotest Sport, S4P model). 40 bench press exercises (25 kg) were analysed at concentric contraction phase and at maximum velocity, carried out by three different subjects (age: 26.74 ± 1.2 years, height: 175.74 ± 4.04 cm, weight: 78.7 ± 3.35 kg). Variables analysed comprised maximum velocity, maximum estimated force and estimated peak power. The data from both devices was collected simultaneously. Three simple lineal regression models were developed, supplied by the linear position measuring device (LPM) on the basis of the accelerometer´s (AC) data. The assumption of independence of errors was compared by means of the Durbin-Watson test. Partial autocorrelation coefficients were calculated for a p<.05 significance level. It has not been possible to confirm the presence of a general correlation between the measurements of both devices. The data was characterised by a generalised autocorrelation and it is recommended that strategies reflecting error control resulting from the data dependence factor be applied when measuring an athlete´s performance. An inter-machine correlation was only found in one of the non conclusive cases: (Peak Power) variable and subject 1, r(10) = .64, p = .024. No partial autocorrelation was found. The AC device obtained higher average and dispersion values than the LPM device. The results show the probability of an increase to the value of uncertainty of the AC device measurements in accordance with Metrology specified guidelines. Both devices should not be used interchangeably when assessing and monitoring training.El estudio pretende caracterizar la confiabilidad entre dos instrumentos, medidor de posicionamiento lineal (MPL, dinamómetro inercial T-Force) y el acelerómetro (AC) 3-D (Myotest Sport, modelo S4P) habituales en la medición de variables de rendimiento. Fueron analizados 40 ensayos en la realización del ejercicio press banca (25 kg) en fase concéntrica a la máxima velocidad por tres sujetos (26.74 ± 1.2 años, 175.74 ± 4.04 cm, 78.7 ± 3.35 kg). Las variables analizadas fueron velocidad máxima, fuerza máxima estimada y pico de potencia estimado. Ambos aparatos obtuvieron los datos simultáneamente. Se desarrollaron tres modelos de regresión lineal simple proporcionados por el medidor de posicionamiento lineal (MPL) a partir de los datos del acelerómetro (AC). Se contrastó el supuesto de independencia de los errores mediante la prueba de Durbin-Watson. Se calcularon autocorrelaciones parciales para un nivel de significación p<.05. No ha sido posible confirmar la existencia general de correlaciones entre las medidas de ambos aparatos. Los datos estuvieron caracterizados por una autocorrelación generalizada y se recomienda la utilización de estrategias que contemplen el control del error producido por el factor de dependencia de los datos cuando se miden deportistas. Sólo se encontró correlación entre aparatos en unos de los casos no concluyentes, variable (Pico de Potencia) y sujeto 1, r(10) = .64, p = .024. No se encontraron autocorrelaciones parciales. AC obtiene mayores valores promedio y de dispersión que MPL. Los resultados evidencian probabilidad de aumento del valor de la incertidumbre de la medida en AC conforme a las orientaciones especificadas en Metrología. Ambos aparatos no deberían usarse indistintamente en la evaluación y control del entrenamiento

¿Un futuro sin Cristo? Voces de una generación

Este libro indaga en diferentes temas de la vida humana personal y social a la luz de Cristo. Su punto de partida es el acontecimiento de Jesús de Nazaret, y despliega sus implicaciones culturales, espirituales, sociales, éticas, políticas. Es original en la medida en que se dirige al mundo universitario, sin aceptar de antemano las restricciones que una cultura alejada del cristianismo, o que nunca tuvo contacto con él, parece exigir para entablar un diálogo. En efecto, no presenta ante los interlocutores un cristianismo meramente ético ni presenta la fe cristiana como un puro suplemento espiritual para un Occidente exhausto por sus tensiones internas. Se elige un punto de partida poco frecuente, que describe el camino de la fe teologal y, desde ahí, se hace cargo de las objeciones, las preguntas, las búsquedas y las dificultades de nuestros contemporáneos, señaladamente en el mundo universitario al que pertenecen los autores. https://www.ppc-editorial.com/libro/un-futuro-sin-cristo Portada, Tabla de contenidos y Presentación de Javier Prade

Reliability and comparability of the accelerometer and the linear position measuring device in resistance training

The purpose of this study was to determine the intermachine reliability attained from devices used to measure the common variables in sports performance. Repeatability conditions were established by creating a similar set of conditions under which the measurements were taken from both devices. The objectives of this research were to demonstrate the reliability between two devices in a bench press movement—the linear position measuring device (LPM) isoinertial dynamometer (T-Force) and the 3D (Myotest) accelerometer (AC)—and to compare the existing correlations between maximum velocity, maximum estimated strength, and peak power estimate variables in the bench press exercise. Forty bench press exercise trials were analyzed simultaneously, performed by 3 different subjects (age: 26.74 ± 1.2 years, height: 175.74 ± 4.04 cm, weight: 78.7 ± 3.35 kg) at maximum velocity (25 kg additional load). Three simple linear regression models were developed, supplied by the LPM on the basis of the AC data. The assumption of independence of errors was compared by means of the Durban-Watson test, and partial autocorrelation coefficients were established at an overall p < 0.05 significance level. It has not been possible to confirm the presence of a general correlation between the measurements of both devices. Regarding the assumption of independence of errors, the presence of generalized autocorrelation was confirmed. Linear regression analysis revealed an intermachine correlation in one of the nonconclusive cases, (peak power) variable and subject 1, r (10) = 0.640, p = 0.024. No partial autocorrelation was found. The devices should not be used interchangeably as instruments

Comparative analysis of the Spanish and United Kingdom sport-political models

This research conducts a comparative study between the sports models of the United Kingdom (UK) and Spain, emphasizing the complexity of these systems and the need for a multidimensional analysis. The objective of analysing the most important characteristics and differences between the Spanish sports model and structure and the UK sports model, the leading exponent due to its efficiency in the development of sports practice and in obtaining international sports results, to determine possible improvements. To carry out this study, a comparative analysis of the sports models of both countries has been made from a political-sports perspective, and the study of the administrative-organizational structure of sport and the legal regulations that support it, through a mixed design for the analysis of different qualitative dimensions. The most significant conclusions are that in the United Kingdom, a successful transformation has been achieved with a focus on efficiency, public investment, and private partnerships, while in Spain, sporting results have been maintained without a clear strategy, suggesting the need for a re-evaluation of its model. Moreover, the stronger associative culture and a higher number of qualified professionals in the United Kingdom are significant advantages. In conclusion, the United Kingdom's sports model is considered more developed and efficient, highlighting the importance of comprehensive planning and collaboration between public and private entities as key factors for sporting success

Concept Drift Detection to Improve Time Series Forecasting of Wind Energy Generation

Most of the current data sources generate large amounts of data over time. Renewable energy generation is one example of such data sources. Machine learning is often applied to forecast time series. Since data flows are usually large, trends in data may change and learned pat terns might not be optimal in the most recent data. In this paper, we analyse wind energy generation data extracted from the Sistema de Infor mación del Operador del Sistema (ESIOS) of the Spanish power grid. We perform a study to evaluate detecting concept drifts to retrain models and thus improve the quality of forecasting. To this end, we compare the performance of a linear regression model when it is retrained randomly and when a concept drift is detected, respectively. Our experiments show that a concept drift approach improves forecasting between a 7.88% and a 33.97% depending on the concept drift technique appliedMinisterio de Ciencia e Innovación PID2020-117954RB-C22Junta de Andalucía US-1263341Junta de Andalucía P18-RT-277