Effect of thermal shock and ruminal incubation on seed germination in Helianthemum apenninum L. Mill (Cistaceae)

Effect of thermal shock and ruminal incubation on seed germination in Helianthemum apenninum (L.) Mill. (Cistaceae). Here, we analyse the effect of different treatments on seed germination in Helianthemum apenninum (L.) Mill. (Cistaceae), considering scarification with sandpaper, thermal shock simulating the heat from fire, and incubation in the rumen of sheep and goat simulating passage through the gut of ruminants. Mechanical scarification boosted the germination (95% vs. 6% of control treatment), indicating that the seeds have a potentially high germination rate if the coat is eroded. Thermal shock did not improve germination. Incubation in rumen increased seed germination, up to a 32% after 48h in ruminal liquid versus 12% for control seeds in the case of sheep. The results suggest that germination in H. apenninum, while not enhanced by heat from fires, may be enhanced by herbivore ingestion

Probabilistic models on contextuality scenarios

We introduce a framework to describe probabilistic models in Bell experiments, and more generally in contextuality scenarios. Such a scenario is a hypergraph whose vertices represent elementary events and hyperedges correspond to measurements. A probabilistic model on such a scenario associates to each event a probability, in such a way that events in a given measurement have a total probability equal to one. We discuss the advantages of this framework, like the unification of the notions of contexuality and nonlocality, and give a short overview of results obtained elsewhere.Comment: In Proceedings QPL 2013, arXiv:1412.791

Trade and Private R&D in Mexico

Using the National Survey on Employment, Wages, Technology and Training (Enestyc), this paper tries to find the relationship between increasing trade and the proportion of total income Mexican manufacturing firms invest on R&D. Based on two cross-sectional and a panel estimation procedures, the results confirm the idea that increasing the exposure to foreign markets affect the innovative efforts of Mexican firms. We also find that the firms engaging in some kind of R&D do not conform a random sample. More specifically, our results show that, in 1992, the probability of finding a firm engaging resources in some kind of R&D increased with size, a market diversification measure, and a measure of industrial market power at a 2-digit level, while the intensity of the R&D effort depended, on market power and an industry concentration measure. For the 1999 estimation our results show that the probability of R&D investment at a firm level increased with size, a market diversification measure, and exposure to foreign competition, while the magnitude of the R&D effort of a firm was determined by the decrease in average import tariffs at the industry level and by the exporting efforts of the firm. We find strong complementarities between public and private innovation efforts in both years, but find that younger firms are doing stronger R&D efforts in 1999. The 1992- 99 balanced panel results show that exporting firms invest more in R&D while import competing firms invest less, once size, market power and other control variables are taken into account. Our estimation indicates that exporting give firms a great incentive to innovate, and that not only large, but also small firms contribute to the R&D efforts of a nation.R&D, trade liberalization, foreign direct investment, exposure to foreing markets

Search for torsional oscillations in isolated sunspots

In this work we seek evidence for global torsional oscillations in alpha sunspots. We have used long time series of continuum intensity and magnetic field vector maps from the Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) spacecraft. The time series analysed here span the total disk passage of 25 isolated sunspots. We found no evidence of global long-term periodic oscillations in the azimuthal angle of the sunspot magnetic field within $\sim$ 1 degree. This study could help us to understand the sunspot dynamics and its internal structure

Adjusting inequalities for detection-loophole-free steering experiments

We study the problem of certifying quantum steering in a detection-loophole-free manner in experimental situations that require post-selection. We present a method to find the modified local-hidden-state bound of steering inequalities in such a post-selected scenario. We then present a construction of linear steering inequalities in arbitrary finite dimension and show that they certify steering in a loophole-free manner as long as the detection efficiencies are above the known bound below which steering can never be demonstrated. We also show how our method extends to the scenarios of multipartite steering and Bell nonlocality, in the general case where there can be correlations between the losses of the different parties. In both cases we present examples to demonstrate the techniques developed.Comment: 12 pages, 4 figure

A Combinatorial Approach to Nonlocality and Contextuality

So far, most of the literature on (quantum) contextuality and the Kochen-Specker theorem seems either to concern particular examples of contextuality, or be considered as quantum logic. Here, we develop a general formalism for contextuality scenarios based on the combinatorics of hypergraphs which significantly refines a similar recent approach by Cabello, Severini and Winter (CSW). In contrast to CSW, we explicitly include the normalization of probabilities, which gives us a much finer control over the various sets of probabilistic models like classical, quantum and generalized probabilistic. In particular, our framework specializes to (quantum) nonlocality in the case of Bell scenarios, which arise very naturally from a certain product of contextuality scenarios due to Foulis and Randall. In the spirit of CSW, we find close relationships to several graph invariants. The recently proposed Local Orthogonality principle turns out to be a special case of a general principle for contextuality scenarios related to the Shannon capacity of graphs. Our results imply that it is strictly dominated by a low level of the Navascu\'es-Pironio-Ac\'in hierarchy of semidefinite programs, which we also apply to contextuality scenarios. We derive a wealth of results in our framework, many of these relating to quantum and supraquantum contextuality and nonlocality, and state numerous open problems. For example, we show that the set of quantum models on a contextuality scenario can in general not be characterized in terms of a graph invariant. In terms of graph theory, our main result is this: there exist two graphs $G_1$ and $G_2$ with the properties \begin{align*} \alpha(G_1) &= \Theta(G_1), & \alpha(G_2) &= \vartheta(G_2), \\[6pt] \Theta(G_1\boxtimes G_2) & > \Theta(G_1)\cdot \Theta(G_2),& \Theta(G_1 + G_2) & > \Theta(G_1) + \Theta(G_2). \end{align*}Comment: minor revision, same results as in v2, to appear in Comm. Math. Phy

Desarrollo de conocimientos científicos procedimentales a partir de la medida de volumen en la formación inicial docente

Este trabajo presenta el diseño y aplicación de actividades para desarrollar conocimiento científico procedimental a través de la medida del volumen. Para ello, se plantean actividades que crean conflictos cognitivos a partir de la inclusión de objetos que flotan en el agua o son solubles. Varios grupos de estudiantes fueron grabados en vídeo con objeto de analizar las estrategias utilizadas, las dificultades y las ideas que aparecen durante su resolución. Estas serían evaluadas y discutidas en clase posteriormente. Para determinar si el aprendizaje era duradero, se pidió a dos grupos de estudiantes realizar otra actividad similar tres años más tarde. Los resultados obtenidos muestran que la realización de estas actividades y la evaluación de las estrategias pueden funcionar como un recurso eficaz para la profundización de conceptos y procedimientos

Como el herrero que machaca sobre el yunque hasta moldear la forma ideal. La Nueva Provincia y su construcción del llamado “delincuente subversivo” (1975-1977)

Todo lo que se pueda decir desde estas columnas será reiterativo. Y, sin embargo, como el herrero que machaca sobre el yunque hasta moldear la forma ideal, no podemos menos que insistir sobre la magnitud que está alcanzando esta tragedia argentina, repitiendo lo que, inconcebible y absurdamente, se tarda tanto en admitir: el país está en guerra y su enemigo, artero e implacable, entre nosotros. Ningún argentino está a salvo de esta guerra, porque no hay fronteras que puedan separarlo del campo de batalla. (…) Ayer cayeron dos hombres, dos soldados. En el mismo lugar por donde 24 horas antes, cientos de familias bahienses desfilaron bajo el sol, rodeadas de verdor, disfrutando una vida que creen asegurada. Ninguna supo que muy cerca de ellas, disimuladas, estaban las fuerzas asesinas. Así es la guerra.Fil: Zapata, Ana Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca; Argentina. Universidad Nacional del Sur; Argentina. Universidad de Buenos Aires; Argentin