A new entropy based on a group-theoretical structure

A multi-parametric version of the nonadditive entropy $S_{q}$ is introduced. This new entropic form, denoted by $S_{a,b,r}$, possesses many interesting statistical properties, and it reduces to the entropy $S_q$ for $b=0$, $a=r:=1-q$ (hence Boltzmann-Gibbs entropy $S_{BG}$ for $b=0$, $a=r \to 0$). The construction of the entropy $S_{a,b,r}$ is based on a general group-theoretical approach recently proposed by one of us \cite{Tempesta2}. Indeed, essentially all the properties of this new entropy are obtained as a consequence of the existence of a rational group law, which expresses the structure of $S_{a,b,r}$ with respect to the composition of statistically independent subsystems. Depending on the choice of the parameters, the entropy $S_{a,b,r}$ can be used to cover a wide range of physical situations, in which the measure of the accessible phase space increases say exponentially with the number of particles $N$ of the system, or even stabilizes, by increasing $N$, to a limiting value. This paves the way to the use of this entropy in contexts where a system "freezes" some or many of its degrees of freedom by increasing the number of its constituting particles or subsystems.Comment: 12 pages including 1 figur

Cosechadoras de cereales: revision del mercado actual

En este artículo nos ocupamos de los últimos modelos de cosechadoras que comercializan las firmas Massey Ferguson, John Deere Ibérica, New Holland, Claas Ibérica y Deutz-Fahr en el mercado nacional

Maquinaria para siega y picado de forrajes.

En este artículo se revisan diversos tipos de máquinas para la recolección de forraje, centrándose especialmente en la siega y el picado. Se analizan las características técnicas de más de cien modelos disponibles en el mercado, clasificándolos según las labores que realizan

Maquinaria de recoleccion: novedades en la feria

En la 29a edición de la Feria Internacional de Maquinaria Agrícola, clausurada el pasado 13 de abril, se han dado cita las principales firmas fabricantes de maquinaria agrícola tanto nacionales como extranjeras, así como un buen número de empresas relacionadas con el sector, llegando a sumar un total de 1.125 expositores. Se han presentado grandes máquinas de recolección, tanto de cereales como de forraje, así como equipos para recolección de frutas y hortalizas

Chaos edges of zz-logistic maps: Connection between the relaxation and sensitivity entropic indices

Chaos thresholds of the $z$-logistic maps $x_{t+1}=1-a|x_t|^z$ $(z>1; t=0,1,2,...)$ are numerically analysed at accumulation points of cycles 2, 3 and 5. We verify that the nonextensive $q$-generalization of a Pesin-like identity is preserved through averaging over the entire phase space. More precisely, we computationally verify $\lim_{t \to\infty}< S_{q_{sen}^{av}} >(t)/t= \lim_{t \to\infty}(t)/t \equiv \lambda_{q_{sen}^{av}}^{av}$, where the entropy $S_{q} \equiv (1- \sum_i p_i^q)/ (q-1)$ ($S_1=-\sum_ip_i \ln p_i$), the sensitivity to the initial conditions $\xi \equiv \lim_{\Delta x(0) \to 0} \Delta x(t)/\Delta x(0)$, and $\ln_q x \equiv (x^{1-q}-1)/ (1-q)$ ($\ln_1 x=\ln x$). The entropic index $q_{sen}^{av}0$ depend on both $z$ and the cycle. We also study the relaxation that occurs if we start with an ensemble of initial conditions homogeneously occupying the entire phase space. The associated Lebesgue measure asymptotically decreases as $1/t^{1/(q_{rel}-1)}$ ($q_{rel}>1$). These results led to (i) the first illustration of the connection (conjectured by one of us) between sensitivity and relaxation entropic indices, namely $q_{rel}-1 \simeq A (1-q_{sen}^{av})^\alpha$, where the positive numbers $(A,\alpha)$ depend on the cycle; (ii) an unexpected and new scaling, namely $q_{sen}^{av}(cycle n)=2.5 q_{sen}^{av}(cycle 2)+ \epsilon$ ($\epsilon=-0.03$ for $n=3$, and $\epsilon = 0.03$ for $n=5$).Comment: 5 pages, 5 figure

Effect of energy density and virginiamycin supplementation in diets on growth performance and digestive function of finishing steers.

ObjectiveThis study was determined the influence of virginiamycin supplementation on growth-performance and characteristics of digestion of cattle with decreasing dietary net energy value of the diet for maintenance (NEm) from 2.22 to 2.10 Mcal/kg.MethodsEighty crossbred beef steers (298.2±6.3 kg) were used in a 152-d performance evaluation consisting of a 28-d adaptation period followed by a 124-d growing-finishing period. During the 124-d period steers were fed either a lesser energy dense (LED, 2.10 Mcal/kg NEm) or higher energy dense (HED, 2.22 Mcal/kg NEm) diet. Diets were fed with or without 28 mg/kg (dry matter [DM] basis) virginiamycin in a 2×2 factorial arrangement. Four Holstein steers (170.4±5.6 kg) with cannulas in the rumen (3.8 cm internal diameter) and proximal duodenum were used in 4×4 Latin square experiment to study treatment effects on characteristics of digestion.ResultsNeither diet energy density nor virginiamycin affected average daily gain (p&gt;0.10). As expected, dry matter intake and gain efficiency were greater (p&lt;0.01) for LED- than for HED-fed steers. Virginiamycin did not affect estimated net energy value of the LED diet. Virginiamycin increased estimated NE of the HED diet. During daylight hours when the temperature humidity index averaged 81.3±2.7, virginiamycin decreased (p&lt;0.05) ruminal temperature. Virginiamycin did not influence (p&gt;0.10) ruminal or total tract digestion. Ruminal (p = 0.02) and total tract digestion (p&lt;0.01) of organic matter, and digestible energy (p&lt;0.01) were greater for HED vs LED. Ruminal microbial efficiency was lower (p&lt;0.01) for HED vs LED diets.ConclusionThe positive effect of virginiamycin on growth performance of cattle is due to increased efficiency of energy utilization, as effects of virginiamycin on characteristics of digestion were not appreciable. Under conditions of high ambient temperature virginiamycin may reduce body temperature

Gestión óptima de aguas subterráneas : regulación frente a no regulación

En este artículo se comparan dos modelos de gestión de aguas subterráneas: control y no-control. La diferencia entre ambos viene dada porque en el primero de ellos se computa el coste de uso del recurso, mientras que en el segundo no. La demanda de agua subterránea se desagrega por cultivos lo que permite obtener una asignación inter e intratemporal del recurso. Asimismo se realiza la aplicación sobre el acuífero de Ascoy-Sopalmo (Cuenca del Segura). La obtención del valor presente del excedente neto de los agricultores en ambos escenarios permite concluir que la pérdida de eficiencia es mínima para unos valores normales de las tasas de descuento y recarga.In this paper two management models of groundwater (control and no-control) are compared. The difference between these models is that in the first one user cost is considered whilst in the second one is not. The groundwater demand is disaggregated by crops, which makes possible to obtain an inter and intratemporal resource allocation. Furthermore, an application to the aquifer of Ascoy-Sopalmo (Segura Basin) is carried out. From the present value of the farmer's net surplus, derived in both models, we can conclude that the efficiency loss is minimum for normal values of the discount rate and recharge rate

B cells in the formation of Tertiary Lymphoid Organs in autoimmunity, transplantation and tumorigenesis.

TLS develop in target organs of autoimmune diseases, transplantation and cancer. • TLS can function as germinal centres supporting B-cell selection/differentiation. • TLS can be destructive or have beneficial effects at the site of inflammation/disease. • Therapeutic targeting of TLS results in beneficial effects in patients, though inhibition may lead to immune suppression while stimulation may lead to autoimmunity. Tertiary lymphoid organs named also tertiary lymphoid structures (TLS) often occur at sites of autoimmune inflammation, organ transplantation and cancer. Although the mechanisms for their formation/function are not entirely understood, it is known that TLS can display features of active germinal centres supporting the proliferation and differentiation of (auto)-reactive B cells. In this Review, we discuss current knowledge on TLS-associated B cells with particular reference on how within diseased tissues these structures are linked to either deleterious or protective outcomes in patients and the potential for therapeutic targeting of TLS through novel drugs

Doping Effects In Off-stoichiometric Glow Discharge Amorphous Silicon Nitride

The effects of boron and phosphorus doping on the electrical properties of a-SiNx:H films are studied. The material is obtained by the glow discharge of SiH4 and N2 mixtures. It is found that for Si-rich materials boron doping produces large conductivity variations while phosphorus appears to be a much less efficient dopant. A phenomenological explanation is given assuming that phosphorus prefers to form bonds in accordance with its own valence configuration; i.e., it will go substitutionally to threefold coordinated N sites. Experimental evidence of such behavior obtained from published IR transmission measurements confirms this assumption.441116118IEEE Italy Sectio