Towards an HH-theorem for granular gases

The $H$-theorem, originally derived at the level of Boltzmann non-linear kinetic equation for a dilute gas undergoing elastic collisions, strongly constrains the velocity distribution of the gas to evolve irreversibly towards equilibrium. As such, the theorem could not be generalized to account for dissipative systems: the conservative nature of collisions is an essential ingredient in the standard derivation. For a dissipative gas of grains, we construct here a simple functional $\mathcal H$ related to the original $H$, that can be qualified as a Lyapunov functional. It is positive, and results backed by three independent simulation approaches (a deterministic spectral method, the stochastic Direct Simulation Monte Carlo technique, and Molecular Dynamics) indicate that it is also non-increasing. Both driven and unforced cases are investigated

Reconstruction of the rotation center of the hip after oblong cups in revision total hip arthroplasty

Background The preoperative bone defect and the reconstruction of the center of rotation of the hip are critical in acetabular revision surgery. Uncemented oblong cups are employed in order to manage these issues. We analyzed the clinical results and rates of revision of two different uncemented oblong cups, the reconstruction of the center of rotation of the hip, as well as the rate of radiological loosening and possible risk factors. Materials and methods Forty-five patients (46 hips) underwent acetabular revision surgery using two different uncemented oblong cups.Weassessed the clinical results and the survival rate for revision and aseptic loosening. Intraoperative bone loss was classified according to Paprosky, and acetabular reconstruction was assessed according to Ranawat. The mean follow-up was 7.2 years (range 4–11 years). Results There were four re-revisions (three due to aseptic loosening); the survival rate for re-revision due to aseptic loosening was 60.1 % at seven years. The mean distance between the center of the femoral head prosthesis and the approximate center of the femoral head improved from 21.5 to 10.2 mm. Thirteen cups showed radiological loosening; the survival rate for radiological loosening at seven years was 40.54 %. A smaller postoperative horizontal distance was correlated with cup loosening. Conclusions Although optimal acetabular reconstruction can be achieved by using oblong uncemented cups in revision hip surgery, the clinical and radiological results are not encouraging. Excessive medialization of the cup may increase the rate of loosenin

Noncommutative effective LQC: A (pre-)inflationary dynamics investigation

We conduct a (pre-)inflationary dynamics study within the framework of a simple noncommutative extension of effective loop quantum cosmology -- put forward recently by the authors -- which preserves its key features (in particular, the quantum bounce is maintained). A thorough investigation shows that the (pre-)inflationary scenario associated to the chaotic quadratic potential is in the overall the same as the one featured in standard loop quantum cosmology (which reinforces the conclusion reached by the authors in a preliminary analysis). Hence, this (pre-)inflationary scenario does not easily distinguish between standard loop quantum cosmology and the aforementioned noncommutative scheme. It is argued that a particular tuning of the noncommutativity parameter could accommodate for subtle effects at the level of primordial perturbations (the hybrid quantization framework being a tentative route of analysis).Comment: 22 pages, 18 figures, 1 tabl

A multi-isotope analysis of Neolithic human groups in the Yonne valley, Northern France: insights into dietary patterns and social structure

With the arrival of the Neolithic to Europe, new ways of life and new subsistence strategies emerged. In the Paris Basin (northern France), the appearance of some monumental funerary structures during theMiddle Neolithic highlights in particular the increasing complexity of the social organisation. At the same time, several sites, such as open-air cemeteries, do not display any evidence of such arrangement. In the southeast of this area, the two primary routes of neolithisationmeet. Several funerary parameters attest to the diverse influence received from other surrounding cultures. In order to assess potential differences in diet, and therefore on purported social distinctions at the inter- and intra-site level, stable isotope analyses (carbon, nitrogen and sulphur) were performed on bone collagen of humans (n = 177) and non-human animals (n = 62) fromseven archaeological sites located in the same area (< 10 km). This study is the biggest so far on French Neolithic material and thus allows for an extensive investigation at a regional scale. Results show that the human nitrogen isotopic ratios are relatively enriched in nitrogen-15 comparing to those of the domesticated animals. This reflects a trophic step that is rarely observed elsewhere in the surrounding Neolithic people, particularly for humans of the biggest site Gurgy 'Les Noisats'. Though zooarchaeological data support a predominant cattle consumption, here, we propose a mixed protein consumption of cattle and pig, possibly complemented with some freshwater resources. Furthermore, carbon, nitrogen and sulphur isotopic ratios suggest some slight differences between sexes and sites. This sexual distinction has rarely been identified in the diet within a Neolithic context. Some variations over time were also detected. On the whole, this study seems to support previous observations made from burial practices about a specific regional Neolithic pattern in the Paris Basin as well as bring new elements into discussion of social organisation in human populations

Well-being of suckling calves under two different rearing systems: case study in the central milk basin of Argentina

En el presente trabajo se llevo a cabo un estudio de caso con enfoque cuantitativo. El objetivo de este estudio fue evaluar el bienestar en teneros lechales durante la época invernal bajo dos diferentes sistemas de crianza, que se utilizan en la zona. Los terneros, se alojaron en dos sistemas: en estaca los machos y en jaula las hembras. Los animales recibieron dos tomas diarias de leche (4 l/día), balanceado iniciador y agua ad libitum. Se registraron pesos iníciales y finales. La ganancia de peso se analizó mediante técnicas estadísticas descriptivas. Se tomaron muestra de saliva para determinar cortisol (CS) en cuatro momentos del día. Los datos fueron analizados para detectar variaciones horarias. El CS no mostró fluctuaciones diarias. Durante quince días y día por medio, se registraron las conductas: parado, echado, comiendo y otras. La metodología de observación y registro utilizada fue el muestreo de barrido a intervalos regulares. Los datos de analizaron con la prueba del c2. El efecto tratamiento fue significativo sobre el comportamiento (p<0,01). Los animales de los dos sistemas gastaron el 50% del tiempo en la conducta de reposo.Well-being of suckling calves under two different rearing systems. Case study in the central milk basin of Argentina. In this paper we conducted a case study with quantitative approach. The aim of this study was to assess welfare in suckling calves during the winter season under two different rearing systems, which are used in the area. Calves were housed in two systems: a stake in males and females cage. All animals received 4 L milk per day, in two servings. Water and a commercial starter were offered ad libitum. Initial and final weights were recorded, weight gain was analyzed using descriptive statistical techniques. Saliva samples were taken at four times over the day, to analyze saliva cortisol (SC). Data were analyzed for time variations. Neither daily fluctuations in SC concentrations nor system effects were detected in SC concentrations. Different behaviors: standing, lying, eating and "others" were observed every other day over a fortnight. Scan sampling at regular intervals was utilized. Data were analyzed by a c2 test. Systems effects were observed on behavioral conducts (p<0.01). Animals in both systems spent 50% of their time lying.Fil: Leva, Paula Edit. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García, M. S.. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Toffoli Arnaudo, Guillermo Daniel. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, A. G.. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Rey, Florencia. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin