Equalization in redundant channels

A miscomparison between a channel's configuration data base and a voted system configuration data base in a redundant channel system having identically operating, frame synchronous channels triggers autoequalization of the channel's historical signal data bases in a hierarchical, chronological manner with that of a correctly operating channel. After equalization, symmetrization of the channel's configuration data base with that of the system permits upgrading of the previously degraded channel to full redundancy. An externally provided equalization command, e.g., manually actuated, can also trigger equalization

Nucleotide sequences modulating the expression of genes in plants

The provides a genetic cassette for the expression of heterologous nucleic acids in response to abiotic stresses such as drought and soil high salinity, regulatory sequences used in the expression cassette, expression vectors carrying these sequences and plants transformed with the same

Optimal strategies to steer and control water waves

In this paper, we propose a new method for controlling surface water waves and their interaction with floating bodies. A floating target rigid body is surrounded by a control region where we design three control strategies of increasing complexity: an active strategy based on controlling the pressure at the air–water interface and two passive strategies where an additional controlled floating device is designed. Such device is modeled both as a membrane and as a thin plate and the effect of this modeling choice on the performance of the overall controlled system is analyzed. We frame this problem as an optimal control problem where the underlying state dynamics is represented by a system of coupled partial differential equations describing the interaction between the surface water waves and the floating target body in the frequency domain. An additional intermediate coupling is then added when considering the control floating device. The optimal control problem then aims at minimizing a cost functional which weights the unwanted motions of the floating body. A system of first-order necessary optimality conditions is derived and numerically solved using the finite element method. The efficacy of this new method for reducing hydrodynamic loads on floating objects has been shown through numerical simulations

MRP transporters and low phytic acid mutants in major crops : main pleiotropic effects and future perspectives

Phytic acid (PA) represents the major storage form of seed phosphate (P). During seed maturation, it accumulates as phytate salts chelating various mineral cations, therefore reducing their bioavailability. During germination, phytase dephosphorylates PA releasing both P and cations which in turn can be used for the nutrition of the growing seedling. Animals do not possess phytase, thus monogastric animals assimilate only 10% of the phytate ingested with feed, whilst 90% is excreted and may contribute to cause P pollution of the environment. To overcome this double problem, nutritional and environmental, in the last four decades, many low phytic acid (lpa) mutants (most of which affect the PA-MRP transporters) have been isolated and characterized in all major crops, showing that the lpa trait can increase the nutritional quality of foods and feeds and improve P management in agriculture. Nevertheless, these mutations are frequently accompanied by negative pleiotropic effects leading to agronomic defects which may affect either seed viability and germination or plant development or in some cases even increase the resistance to cooking, thus limiting the interest of breeders. Therefore, although some significant results have been reached, the isolation of lpa mutants improved for their nutritional quality and with a good field performance remains a goal so far not fully achieved for many crops. Here, we will summarize the main pleiotropic effects that have been reported to date in lpa mutants affected in PA-MRP transporters in five productive agronomic species, as well as addressing some of the possible challenges to overcome these hurdles and improve the breeding efforts for lpa mutants

Plant MYB Transcription Factors: Their Role in Drought Response Mechanisms

Water scarcity is one of the major causes of poor plant performance and limited crop yields worldwide and it is the single most common cause of severe food shortage in developing countries. Several molecular networks involved in stress perception, signal transduction and stress responses in plants have been elucidated so far. Transcription factors are major players in water stress signaling. In recent years, different MYB transcription factors, mainly in Arabidopsis thaliana (L.) Heynh. but also in some crops, have been characterized for their involvement in drought response. For some of them there is evidence supporting a specific role in response to water stress, such as the regulation of stomatal movement, the control of suberin and cuticular waxes synthesis and the regulation of flower development. Moreover, some of these genes have also been characterized for their involvement in other abiotic or biotic stresses, an important feature considering that in nature, plants are often simultaneously subjected to multiple rather than single environmental perturbations. This review summarizes recent studies highlighting the role of the MYB family of transcription factors in the adaptive responses to drought stress. The practical application value of MYBs in crop improvement, such as stress tolerance engineering, is also discussed

Assessment of Hermetia illucens larvae performance reared on raw or contaminated peanut by-products with Aspergillus flavus and Fusarium graminearum

The peanut supply chain is characterised by a high production of by-products, mainly shells and small pods, often discarded by processing companies. However, the richness of nutritive substances makes these products valuable as feed substrates for Hermetia illucens larvae rearing. Therefore, the aims of this work were to (1) evaluate the performance of H. illucens larvae reared on peanut by-products and (2) study the effect of various levels of fungal contamination in by-products on H. illucens larvae performance, focusing on growth and mortality. Two agro-industrial peanut by-products (rich by-product, R; poor by-product, P) were ground and mixed in different percentages (0-100%, step 10%) to obtain 11 different feeding substrates, then rehydrated to 70% moisture. Three different trials were conducted using these substrates, with three-day-old H. illucens larvae reared for 10 days. Whereas, the effect of fungal contamination was investigated by inoculating chicken feed (standard, S) and substrate P5R5 (50% P and 50% R) with two spore suspensions (Aspergillus flavus and Fusarium graminearum, 105 spore/mL), at three different inoculation times (5, 3 and 0 days before the addition of larvae). The substrate composition considerably impacted larval growth, with the highest larval weight increase obtained when R reached 50% in the substrate. Fungal contamination in by-products significantly reduced larvae performance, with a stronger negative effect from A. flavus. These findings suggest the potential for enhancing peanut by-products as a rearing substrate for H. illucens larvae, although the composition and the possible fungal contamination may reduce the effectiveness of the process

Pyrethroid resistance in Italian populations of the mite Varroa destructor: a focus on the Lombardy region

Varroa destructor Anderson et Trueman (Acari Varroidae) is a major pest of honey bees and synthetic acaricide treatments remain the most effective tool to contain its infestations. In 1991, pyrethroid resistance was first reported in Lombardy, and is now spread worldwide. Recently, three different mutations (L925V/I/M) occurring in the voltage-gated sodium channel have been associated with tau-fluvalinate resistance. Furthermore, in the literature, indirect evidence from laboratory bioassays have indicated that high levels of esterases may be involved in mites resistant to tau-fluvalinate. This study provides an update on the actual spread of target-site resistance to tau-fluvalinate in V. destructor samples collected in the Lombardy region. TaqMan assays showed that mutation L925V is present in this area, however only low frequencies of this resistant allele were detected. The majority of resistant mites were found in the homozygous form (11%), and only a small fraction possessed the heterozygous genotype (2%). Additionally, a protocol was set up to detect esterase activity directly in single mites. Slight variability was observed among different populations collected in Lombardy. Additional studies are needed to confirm the involvement of esterases in resistance to pyrethroids in V. destructor and whether this can be correlated to changes in enzyme activity

Characterization of the symbiotic nitrogen-fixing common bean Low phytic acid (Lpa1) mutant response to water stress

The common bean (Phaseolus vulgaris L.) low phytic acid (lpa1) biofortified genotype produces seeds with improved nutritional characteristics and does not display negative pleiotropic effects. Here we demonstrated that lpa1 plants establish an efficient nitrogen-fixing symbiosis with Rhizobium etli CE3. The lpa1 nodules showed a higher expression of nodule-function related genes than the nodules of the parental wild type genotype (BAT 93). We analyzed the response to water stress of lpa1 vs. BAT 93 plants grown under fertilized or under symbiotic N2-fixation conditions. Water stress was induced by water withholding (up to 14% soil moisture) to fertilized or R. etli nodulated plants previously grown with normal irrigation. The fertilized lpa1 plants showed milder water stress symptoms during the water deployment period and after the rehydration recovery period when lpa1 plants showed less biomass reduction. The symbiotic water-stressed lpa1 plants showed decreased nitrogenase activity that coincides with decreased sucrose synthase gene expression in nodules; lower turgor weight to dry weight (DW) ratio, which has been associated with higher drought resistance index; downregulation of carbon/nitrogen (C/N)-related and upregulation of stress-related genes. Higher expression of stress-related genes was also observed in bacteroids of stressed lpa1 plants that also displayed very high expression of the symbiotic cbb3 oxidase (fixNd)