Crop load does not increase the photosynthetic rate in Citrus leaves under regular cropping conditions. A study throughout the year

[EN] The objective of this work was to study the influence of fruit load on CO2 assimilation in the leaves of citrus trees presenting alternate bearing habits, and the importance of this factor on photosynthetic rate variability throughout the year and under regular cropping conditions. The photosynthetic rate was measured on 60 days throughout the year on field-grown sweet orange plants under natural conditions in the Valencian Community, the most important citrus-producing area of Spain. The experiments were performed on the 'on' (high crop) and 'off' (low crop) bearing 40-year-old Salustiana sweet orange trees growing in the same orchard. Gas exchange and fluorescence parameters were measured during the year in young and old leaves on sun-exposed branches with and without fruit in the 'on' trees, and in fruitless branches of the 'off' trees. In non-manipulated Citrus trees, fruit load has no significant effect in any season on the photosynthetic rate in the leaves from branches without fruit. However, in high crop trees, the leaves of branches bearing fruit present a slightly lower photosynthetic rates (approx. 10%) than those of fruitless branches. Variations in mineral content (N, K and P) might explain not only these differences, but also the lower photosynthesis rate observed in old leaves (13-24 month-old leaves). Environmental conditions were the main factor for the variation of the photosynthetic rate, with variability of the monthly mean photosynthetic rate being much lower than that between days in the same month.González Nebauer, S.; Arenas, C.; Rodríguez Gamir, J.; Bordon, Y.; Fortunato Almeida, A.; Monerri Huguet, MC.; Guardiola Barcena, JL.... (2013). Crop load does not increase the photosynthetic rate in Citrus leaves under regular cropping conditions. A study throughout the year. Scientia Horticulturae. 160:358-365. doi:10.1016/j.scienta.2013.06.008S35836516

Dynamic Power Management for Reactive Stream Processing on the SCC Tiled Architecture

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License(http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Dynamic voltage and frequency scaling} (DVFS) is a means to adjust the computing capacity and power consumption of computing systems to the application demands. DVFS is generally useful to provide a compromise between computing demands and power consumption, especially in the areas of resource-constrained computing systems. Many modern processors support some form of DVFS. In this article we focus on the development of an execution framework that provides light-weight DVFS support for reactive stream-processing systems (RSPS). RSPS are a common form of embedded control systems, operating in direct response to inputs from their environment. At the execution framework we focus on support for many-core scheduling for parallel execution of concurrent programs. We provide a DVFS strategy for RSPS that is simple and lightweight, to be used for dynamic adaptation of the power consumption at runtime. The simplicity of the DVFS strategy became possible by sole focus on the application domain of RSPS. The presented DVFS strategy does not require specific assumptions about the message arrival rate or the underlying scheduling method. While DVFS is a very active field, in contrast to most existing research, our approach works also for platforms like many-core processors, where the power settings typically cannot be controlled individually for each computational unit. We also support dynamic scheduling with variable workload. While many research results are provided with simulators, in our approach we present a parallel execution framework with experiments conducted on real hardware, using the SCC many-core processor. The results of our experimental evaluation confirm that our simple DVFS strategy provides potential for significant energy saving on RSPS.Peer reviewe

CTD kinase I is required for the integrity of the rDNA tandem array

The genomic stability of the rDNA tandem array is tightly controlled to allow sequence homogenization and to prevent deleterious rearrangements. In this report, we show that the absence of the yeast CTD kinase I (CTDK-I) complex in null mutant strains leads to a decrease in the number of tandem rDNA repeats. Reintroduction of the missing gene induces an increase of rDNA repeats to reach a copy number similar to that of the original strain. Interestingly, while expansion is dependent on Fob1, a protein required for replication fork blocking activity in rDNA, contraction occurs in the absence of Fob1. Furthermore, silencing of class II genes at the rDNA, a process connected to rDNA stability, is not affected. Ctk1, the kinase subunit of the CTDK-I complex is involved in various steps of mRNA synthesis. In addition, we have recently shown that Ctk1 is also implicated in rRNA synthesis. The results suggest that the RNA polymerase I transcription defect occurring in a ctk1 mutant strain causes rDNA contraction

Nanotechnology Research: Applications in Nutritional Sciences12

The tantalizing potential of nanotechnology is to fabricate and combine nanoscale approaches and building blocks to make useful tools and, ultimately, interventions for medical science, including nutritional science, at the scale of ∼1–100 nm. In the past few years, tools and techniques that facilitate studies and interventions in the nanoscale range have become widely available and have drawn widespread attention. Recently, investigators in the food and nutrition sciences have been applying the tools of nanotechnology in their research. The Experimental Biology 2009 symposium entitled “Nanotechnology Research: Applications in Nutritional Sciences” was organized to highlight emerging applications of nanotechnology to the food and nutrition sciences, as well as to suggest ways for further integration of these emerging technologies into nutrition research. Speakers focused on topics that included the problems and possibilities of introducing nanoparticles in clinical or nutrition settings, nanotechnology applications for increasing bioavailability of bioactive food components in new food products, nanotechnology opportunities in food science, as well as emerging safety and regulatory issues in this area, and the basic research applications such as the use of quantum dots to visualize cellular processes and protein-protein interactions. The session highlighted several emerging areas of potential utility in nutrition research. Nutrition scientists are encouraged to leverage ongoing efforts in nanomedicine through collaborations. These efforts could facilitate exploration of previously inaccessible cellular compartments and intracellular pathways and thus uncover strategies for new prevention and therapeutic modalities