Sharp detection of oscillation packets in rich time-frequency representations of neural signals

Brain oscillations most often occur in bursts, called oscillation packets, which span a finite extent in time and frequency. Recent studies have shown that these packets portray a much more dynamic picture of synchronization and transient communication between sites than previously thought. To understand their nature and statistical properties, techniques are needed to objectively detect oscillation packets and to quantify their temporal and frequency extent, as well as their magnitude. There are various methods to detect bursts of oscillations. The simplest ones divide the signal into band limited sub-components, quantifying the strength of the resulting components. These methods cannot by themselves cope with broadband transients that look like genuine oscillations when restricted to a narrow band. The most successful detection methods rely on time-frequency representations, which can readily show broadband transients and harmonics. However, the performance of such methods is conditioned by the ability of the representation to localize packets simultaneously in time and frequency, and by the capabilities of packet detection techniques, whose current state of the art is limited to extraction of bounding boxes. Here, we focus on the second problem, introducing two detection methods that use concepts derived from clustering and topographic prominence. These methods are able to delineate the packets’ precise contour in the time-frequency plane. We validate the new approaches using both synthetic and real data recorded in humans and animals and rely on a super-resolution time-frequency representation, namely the superlets, as input to the detection algorithms. In addition, we define robust tests for benchmarking and compare the new methods to previous techniques. Results indicate that the two methods we introduce shine in low signal-to-noise ratio conditions, where they only miss a fraction of packets undetected by previous methods. Finally, algorithms that delineate precisely the border of spectral features and their subcomponents offer far more valuable information than simple rectangular bounding boxes (time and frequency span) and can provide a solid foundation to investigate neural oscillations’ dynamics

THE INFLUENCE OF THE FORERUNNER PLANT, FERTILISATION LEVEL AND CLIMATIC CONDITIONS ON THE TOTAL WET AND DRY GLUTEN CONTENT OF WINTER WHEAT SEEDS

Abstract. The quality of the cultivated plants depends on the employed cultivar and hybrid, climatic characteristics during the cultivation year and also, on the applied technology. There are important references in scientific literature that emphasize the implication of different factors in influencing the quality of the obtained production. They underline the importance of nitrogen on the increase in protein content, on wet and dry mass gluten also on the amelioration of quality indexes of gluten. The authors mention the role of the ameliorative plant (pea) on the wheat quality and the important role of the regionalised wheat races on the quality of raw protein and gluten

Crop Rotation and Irrigation Influence on Wheat Yield and the Correlations Climate-Yield in the Crişurilor Plain Conditions

The paper is based on the researches carried out during 2003-2008 in a long term trial placed in 1990 on the preluvosoil from Oradea. Climate indicator “de Martonne aridity index” (IdM) was used for quantification the correlation between climate and wheat yield in unirrigated and irrigated conditions and new class called “arid” was purposed for climate index characterization. Maintaining the soil water reserve on 0-50 cm depth between easily available water content and field capacity using the irrigation determined the increase of the IdM values for period IV – VI with 79% in 2003, 73% in 2004, 36% in 2005,16% in 2006, 162% in 2007 and with 131% in 2008; using the irrigation and the improvement of the microclimate conditions determined to obtain the yield gains, very significant every year and every crop rotation studied; both in unirrigated conditions and in irrigated conditions, the smallest yields wheat were obtained in monocrop and the biggest in the wheat – maize – soybean crop rotation; in the all three crop rotation, the direct links statistically assured were registered between the values of the De Martonne aridity index and yields in unirrigated and irrigated wheat. These correlations sustain the need of the irrigation in wheat from Crisurilor Plain; correlation between De Martonne aridity index is stronger (R2 = 0.7361xx) in the wheat – maize – soybean crop rotation in comparison with wheat – maize crop rotation (R2 = 0.6215x) and with wheat monocrop (R2 = 0.6105x). As consequence, crop rotation of wheat-maize-soybean is recomanded because the climate and microclimate conditions are better use