Rice pathogens intercepted on seeds originating from 11 African countries and from the USA

1,916 rice seed samples from 11 African countries and the USA were tested for the presence of pathogenic microorganisms or those affecting seed quality. Bacillus spp., Pantoea spp., Sphingomonas sp. and the fungi Acremoniella sp., Alternaria sp., Aspergillus flavus, A. fumigatus, A. niger, Chaetomium sp., Curvularia sp., Fusarium oxysporum, F. solani, Fusarium sp., Helminthosporium sp., Microdochium oryzae, Nigrospora oryzae, Penicillium sp., Pestalotia sp., Phoma sp., Magnaporthe oryzae, Rhizopus sp., Sarocladium sp. and Tilletia barclayana were isolated. The highest incidence values were obtained with Curvularia sp., Microdochium oryzae, A. flavus, F. solani and Nigropora sp. In contrast, these fungi were not isolated from seeds of many countries with Togo having the least affected seeds (nine out of the 24 potential organisms diagnosed). The highest frequencies of these organisms were found on seed samples from Benin (20/22), Burundi and Tanzania (19/24), and Senegal (18/24). Across countries, A. flavus, A. fumigatus, Curvularia sp., F. solani, Nigropora sp., Rhizopus sp. and Microdochium oryzae were the most frequently isolated organisms. Concerning the major diseases, blast was diagnosed only once despite the high number of samples tested

On the inducibility of small trees

The quantity that captures the asymptotic value of the maximum number of appearances of a given topological tree (a rooted tree with no vertices of outdegree $1$) $S$ with $k$ leaves in an arbitrary tree with sufficiently large number of leaves is called the inducibility of $S$. Its precise value is known only for some specific families of trees, most of them exhibiting a symmetrical configuration. In an attempt to answer a recent question posed by Czabarka, Sz\'ekely, and the second author of this article, we provide bounds for the inducibility $J(A_5)$ of the $5$-leaf binary tree $A_5$ whose branches are a single leaf and the complete binary tree of height $2$. It was indicated before that $J(A_5)$ appears to be `close' to $1/4$. We can make this precise by showing that $0.24707\ldots \leq J(A_5) \leq 0.24745\ldots$. Furthermore, we also consider the problem of determining the inducibility of the tree $Q_4$, which is the only tree among $4$-leaf topological trees for which the inducibility is unknown

Earnings forecast bias - a statistical analysis

The evaluation of the reliability of analysts' earnings forecasts is an important aspect of research for different reasons: Many empirical studies employ analysts' consensus forecasts as a proxy for the market's expectations of future earnings in order to identify the unanticipated component of earnings, institutional investors make considerable use of analysts' forecasts when evaluating and selecting individual sharesand the performance of analysts' forecasts sheds light on the process by which agents form expectations about key economic and financial variables. The recent period put forward a well-known phenomenon, namely the existence of a positive bias in experts' anticipations: the latter tend to over-estimate earnings. In this paper, we study the properties of this bias according to various aspects, that is to say according to country, sector, but also according to the size of the companies.earnings forecasts, bias, consensus

Can earnings forecasts be improved by taking into account the forecast bias?

The recent period has highlighted a well-known phenomenon, namely the existence of a positive bias in experts' anticipations. Literature on this subject underlines optimism in the financial analyst community. In this work, our significant contributions are twofold: we provide explanatory bias prediction models which will subsequently allow the calculation of earnings adjusted forecasts, for horizons from 1 to 24 months. We explain the bias using macroeconomic as well as sector and firm specific variables. We obtain some important results. In particular, the macroeconomic variables are statistically significant and their signs are coherent with the intuition. However, we conclude that the microeconomic variables are the main explanatory variables. From the forecast evaluation statistics viewpoints, the adjusted forecasts make it possible quasi-systematically to improve the forecasts of the analysts.Analysts Forecasts

Large field enhancement obtained by combining Fabry-Perot resonance and Rayleigh anomaly in photonic crystal slabs

© 2017 IOP Publishing Ltd. By applying the properties of Fabry-Perot resonance and Rayleigh anomaly, we have shown that a photonic crystal slab can scatter the light from an incident plane wave into a diffracted light with a very large reflection or transmission coefficient. The enhanced field is either a propagating diffracted wave (with a grazing angle of diffraction) or a weakly evanescent diffracted wave, so it can be particularly useful for applications requiring an enhanced propagating field (or an enhanced field with a low attenuation). An efficient effective medium technique is developed for the design of the resonant photonic crystal slabs. Numerical simulations have shown that photonic crystal slabs with low index contrast, such as the ones found in the cell wall of diatoms, can enhance the intensity of the incident light by four orders of magnitude