Transversal inhomogeneities in dilute vibrofluidized granular fluids

The spontaneous symmetry breaking taking place in the direction perpendicular to the energy flux in a dilute vibrofluidized granular system is investigated, using both a hydrodynamic description and simulation methods. The latter include molecular dynamics and direct Monte Carlo simulation of the Boltzmann equation. A marginal stability analysis of the hydrodynamic equations, carried out in the WKB approximation, is shown to be in good agreement with the simulation results. The shape of the hydrodynamic profiles beyond the bifurcation is discussed

Composition and depth of Extensive Green Roof substrate affect the growth of two Mediterranean plant species under different irrigation conditions

Recently, the design of new substrates capable of sustain an adequate plant development in Green Roof systems under Mediterranean climatic conditions is a challenge due to the unfavorable hot and dry conditions. The use of suitable lightweight substrates which can promote an adequate plant growth and maintenance over time is an important achievement as well as the plant species selection. The most commonly used plants in Green Roof systems are the Crassulacean since they are perfectly fitted to drought conditions. In this sense, the use of herbaceous and shrub endemic Mediterranean species could provide an added value in green roof designing under semi‐arid conditions. Therefore, we aim to evaluate the growth of two endemic species (Silene vulgaris (Moench) Garcke and Lagurus ovatus L.) in two different substrate types with two different depths. To be precise, one substrate was made of a mixture of compost and crushed bricks (CB) (1:4; v:v), and the other one was made of compost‐soil‐bricks (CSB) (1:1:3; v:v:v). Physichochemical, biochemical as well as microbiological properties were evaluated in both substrates in order to study its suitability as plant growth basis. The results showed that both substrates showed adequate physichochemical properties to promote plant growth, but the CSB mixture presented better biochemical and microbiological properties than CB, allowing a suitable environment for microbial and plant development. Furthermore, both plant species had higher coverage and grater SPAD values in CSB than in CB mixture, and this growing was higher above deeper substrates (10 cm) than on 5 cm‐substrate depth, being this parameter more significant for plant development than substrate composition.The authors thank the INNPACTO project (IPT‐ 2011‐1017‐310000) by funding from the relevant trial

Population dynamics and adaptative strategies of Martiodrilus carimaguensis (Oligochaeta, Glossoscolecidae), a native species from the well-drained savannas of Colombia

#Martiodrilus carimaguensis (Oligochaeta, Glossoscolecidae) is a large, anecic native earthworm species which was found in natural and disturbed savannas in the Oxisols of the Colombian Llanos. Its population dynamics were studied in a native savanna, and in a 17 year old grazed grass-legume pasture where density and biomass were higher. Monthly cast deposition on the soil surface in the improved pasture was 38.4 x 10(exp 3) fresh casts/ha, eleven times more than in the native savanna. A strong relationship was found between numbers of #M. carimaguensis and numbers of fresh surface casts. Different patterns of adaptation to the dry season were observed for adults and juveniles. Adults are active for eight months whereas juveniles enter diapause 3-4 months earlier. The vertical distribution pattern of the earthworm population also shows marked seasonal changes. (Résumé d'auteur

Correlation Effects on Transport Through Few-Electrons Systems

We study lateral tunneling through a quantum box including electron-electron interactions in the presence of a magnetic field which breaks single particle degeneracies. The conductance at zero temperature as a function of the Fermi energy in the leads consists of a set of peaks related to changing by one the electron occupancy in the box. We find that the position and heights of the peaks are controlled by many-body effects. We compute the conductance up to 8 electrons for several cases where correlation effects dominate. In the range of intermediate fields spin selection rules quench some peaks. At low and high fields the behavior of the conductance as a function of the number of electrons is very different due to big changes in the many-body ground state wavefunctions.Comment: 9 pages, 2 postscript figures, Latex 3.1

Highly expressed genes are preferentially co-opted for C4 photosynthesis

Novel adaptations are generally assembled by co-opting pre-existing genetic components, but the factors dictating the suitability of genes for new functions remain poorly known. In this work, we used comparative transcriptomics to determine the attributes that increased the likelihood of some genes being co-opted for C4 photosynthesis, a convergent complex trait that boosts productivity in tropical conditions. We show that independent lineages of grasses repeatedly co-opted the gene lineages that were the most highly expressed in non-C4 ancestors to produce their C4 pathway. While ancestral abundance in leaves explains which genes were used for the emergence of a C4 pathway, the tissue specificity has surprisingly no effect. Our results suggest that levels of key genes were elevated during the early diversification of grasses and subsequently repeatedly used to trigger a weak C4 cycle via relatively few mutations. The abundance of C4-suitable transcripts therefore facilitated physiological innovation, but the transition to a strong C4 pathway still involved consequent changes in expression levels, leaf specificity, and coding sequences. The direction and amount of changes required for the strong C4 pathway depended on the identity of the genes co-opted, so that ancestral gene expression both facilitates adaptive transitions and constrains subsequent evolutionary trajectories

Desarrollo de equipos electrónicos para su uso docente en materias tecnológicas: un caso práctico

El coste de algunos equipos electrónicos que se emplean en la docencia práctica de materias de tipo tecnológico impide en ocasiones la dotación completa de los laboratorios. Se plantea en este artículo un caso práctico de diseño y construcción de un prototipo de equipo electrónico para su uso en prácticas de asignaturas en las cuales se precise experimentar con la utilización de variadores electrónicos de velocidad. Los resultados obtenidos permiten asegurar que para determinados casos es posible desarrollar equipos de carácter didáctico que realizan funciones similares a los dispositivos industriales, a un coste sensiblemente inferior, obviando, por supuesto, el coste de desarrollo

Osteonecrosis of the jaws and bisphosphonates : report of fifteen cases: therapeutic recommendations

Recently there have been reports of osteonecrosis of the jaw (ONJ) in patients with chronic therapy with bisphosphonates (Bps). So far three drugs have been linked: Pamidronate of disodium, Zoledronic acid and Alendronate of sodium. It is due to a non detected side effect in clinical trials before commercialization, and reverberates significantly in the quality of life of these patients. Most of the cases are seen in oncology patients that have received long term concurrent antineoplasic therapy and were treated sporadically with steroids, together with Bps endovenous, for treatment of cancer and its symptoms. Among these cases we find the reported by R.E. Marx (1), S.L. Ruggiero (2) and J. V. Bagán (3). In this report fifteen cases diagnosed, treated and followed up at the author´s surgery department are presented and some suggestions are given in order to reduce the incidence in patients with cancer who are going to receive Bps, as well as in patients with established ONJ being treated with these drugs who may need a surgical intervention

Efficient negation using abstract interpretation

While negation has been a very active área of research in logic programming, comparatively few papers have been devoted to implementation issues. Furthermore, the negation-related capabilities of current Prolog systems are limited. We recently presented a novel method for incorporating negation in a Prolog compiler which takes a number of existing methods (some modified and improved by us) and uses them in a combined fashion. The method makes use of information provided by a global analysis of the source code. Our previous work focused on the systematic description of the techniques and the reasoning about correctness and completeness of the method, but provided no experimental evidence to evalúate the proposal. In this paper, we report on an implementation, using the Ciao Prolog system preprocessor, and provide experimental data which indicates that the method is not only feasible but also quite promising from the efficiency point of view. In addition, the tests have provided new insight as to how to improve the proposal further. Abstract interpretation techniques are shown to offer important improvements in this application

Traumatic neuroma of the inferior alveolar nerve : a case report

Traumatic neuromas are rare entities which characteristically arise subsequently to surgery and are usually accompanied by pain, typically neuralgic. We present an unusual case of an intraosseous traumatic neuroma of the inferior alveolar nerve following tooth extraction. A 56-year-old man consulted for paresthesias and hyperesthesia in the left mandibular region following extraction of the left mandibular third molar (#38). The panoramic radiograph revealed a radiolucent lesion in the inferior alveolar nerve canal, and CT demonstrated the existence of a mass within the canal, producing widening of the same. Nerve-sparing excisional biopsy was performed. Histopathology and immunohistochemistry were consistent with traumatic neuroma of the left inferior alveolar nerve. After 3 years of follow-up, the patient is asymptomatic and there are no signs of recurrence

Optical Particle Detection in Liquid Suspensions with a Hybrid Integrated Microsystem

AbstractA compact, robust and portable system for optical particle detection in liquid suspensions, achieved through the hybrid integration of commercial components, such as VCSELs and microlenses, in a silicon micromachined structure is presented. We demonstrate the feasibility of fabricating a device providing up to 4 collimated laser beams, with the ability of detecting and distinguishing microparticles of several diameters, even in mixed suspensions. This optical microsystem represents an alternative design for microflow cytometers based on optical fibres, and is aligned with the current tendency set by the Point-of-care devices