Gene Expression Biomarkers for Evaluating Nitrogen Nutritional Status in Rice

Over the last five decades the increase in rice yield has been associated with a dramatic increment in the use of nitrogen (N) fertilizers. Understanding of plant molecular responses to N is critical for our ability to improve the agricultural sustainability of rice cropping systems by developing a comprehensive approach that allows the selection of varieties with enhanced efficiency in their ability to use N and the development of new strategies to better manage N fertilization practices. In order to develop novel tools for real-time assessing of rice N nutritional status, we analyzed the expression profiles of seven putative gene expression markers in the shoots of rice plants grown under different N availability and environmental conditions. Our results suggest that five out of the seven genes analyzed have the potential to be used as agronomic tools to monitor and optimize the N nutritional status of rice

Cross-correlation noise measurements in A/D converters

This is the second paper of a series describing theories and experiments of a new analysis technique able to accurately characterize the time-varying noise of A/D converters (ADC). In the previous work, the effects of the quantization and nonlinearities on the jitter measurement were considered, and an efficient solution to this problem was demonstrated. This paper presents a dual channel measurement technique that is still independent of quantization and nonlinearities, and that allows one to separate from the ADC noise the noise contribution of the test setup. The method, based on the measurement of the cross-correlated noise between the two channels, provides more accurate measurements of the ADC noise than may be possible with traditional test equipmen

A new method for estimating the aperture uncertainty of A/D converters

Aperture uncertainty measurements are strongly influenced by quantization, converter nonlinearity and test setup noise. An original method is here proposed which completely solves the difficulties arising from quantization and nonlinearity. The method estimates the noise distribution function by finely varying the input signal offset. The applicability of the method is proved by the experimental results obtained on 8 and 10 bit converter

In vitro propagation and shoot encapsulation as tools for ex situ conservation of the aquatic plant Ludwigia palustris (L.) Ell.

Ludwigia palustris (L.) Ell. is an aquatic perennial herb present in several regions of Italy, which is one of its native countries. In this research, micropropagation and encapsulation protocols were established from axillary buds of L. palustris. Shoots proliferated on half-strength Murashige and Skoog medium without growth regulators. Different culture vessels were tested. Shoots in GROWTEK bioreactor showed the highest fresh and dry weight and total length while the plantlets grown in the RITA bioreactor showed the highest shoot number per explant. Encapsulation of L. palustris microcuttings with sodium alginate formed small and whitish beads which were stored for 14 or 28 days at 7° or 25°C. Storage for 14 days at both temperatures gave the best results but prolonged storage at 25°C decreased the shoot viability to 73%. After 4 weeks of recovery, all the plantlets showed the typical features of the species. Even though the latest Italian IUCN Red List does not mention L. palustris, conservation measures are proposed at local level because this species locally remains vulnerable mainly due to the loss of adequate habitats.Our protocol could be one of the methods for ex situ conservation of L. palustris particularly because its seed storage behavior is uncertai