Governing by internet architecture

In the past thirty years, the exponential rise in the number of Internet users around the word and the intensive use of the digital networks have brought to light crucial political issues. Internet is now the object of regulations. Namely, it is a policy domain. Yet, its own architecture represents a new regulative structure, one deeply affecting politics and everyday life. This article considers some of the main transformations of the Internet induced by privatization and militarization processes, as well as their consequences on societies and human beings.En los últimos treinta años ha crecido de manera exponencial el número de usuarios de Internet alrededor del mundo y el uso intensivo de conexiones digitales ha traído a la luz cuestiones políticas cruciales. Internet es ahora objeto de regulaciones. Es decir, es un ámbito de la política. Aún su propia arquitectura representa una nueva estructura reguladora, que afecta profundamente la política y la vida cotidiana. Este artículo considera algunas de las principales transformaciones de Internet inducida por procesos de privatización y militarización, como también sus consecuencias en las sociedades y en los seres humanos

Influence of inoculation and phosphorus regimes on symbiotic nitrogen fixation and phosphorus use efficiency of Algerian cowpea (Vigna unguiculata L. (Walp.)) landraces

ArticleTo study the genotypic variation of cowpeas on plant growth and phosphorus (P) uptake which is a function of different P regimes in the soil rhizosphere , 6 landraces of cowpea commonly found in northern Algeria ( NE4, NE10, NE11, NKT5, NKT7, NKB7 ) and 4 landraces from Sahara in southern Algeria (NAG4, NAG5, NAT2 and ND3) were studied during 2013 – 2014 in greenhouse. They were inoculated with Mesorhizobium sp. (S1), Bradyrhizobium sp. (S2) and co – inoculation (S1 – S2) under three P treatments: no P supply (P0), soluble P (PP) and insoluble P (TCP). Only varieties commonly found in northern Algeria nodulated with soluble P (PP) and inoculation containing Mesorhizobium sp . (S1). As a result of the symbiosis, the use of S1 has significantly increased shoot dry weight by 22%, total P content by 20% and P use efficiency for symbiotic nitrogen fixation by 18% compared to no inoculation (T). The landraces from the northern of Algeria expressed a higher growth than those from Sahara in the south of Algeria, especially three of them (NE4, NE10 and NE11) who showed a high performance under all P regimes. We suggest that these three landraces may be useful for improving symbiotic nitrogen fixation in cowpeas when growth is limited by low – P soils and that they could contribute to sustainable farming systems through reduction of farm er’s dependence on fertilizers

Responses of ectomycorrhizal fungi to mineral substrates

Boreal forest soils are complex, heterogeneous growth substrates where organic and mineral components provide nutrient resources for soil organisms and plants. Mineral nutrients are cycled between living and dead organic components of the forest soil and weathering of soil minerals provides an important input of new resources, compensating for losses from the ecosystem. Predicting soil responses to changing climate and management practices is important to determine their effect on forest production. Models for this purpose are largely based on the concept of the soil solution as the interface controlling soil processes such as weathering and nutrient uptake by plants, whereas soil microbiology recognises microbial processes as the driving force in soil nutrient cycling. In boreal forests most tree root tips are colonised by ectomycorrhizal fungi. The mycelia of these symbiotic fungi mediate nutrient uptake by their tree hosts. These fungi are abundant in the organic layer of forest soils and ectomycorrhizal research has therefore largely focused on nutrient uptake from this horizon. Minerals in the soil may, however, also serve as nutrient resources for ectomycorrhizal fungi. Through combined chemical and physical processes fungi can affect nutrient availability by weathering minerals. This thesis describes a field experiment investigating the distribution of different ectomycorrhizal fungi in organic and mineral forest soil horizons, in vitro studies of fungal acidification of artificial substrates with different mineral element composition, microcosm studies of growth and carbon allocation in intact ectomycorrhizal systems colonising heterogeneous mineral substrates and a preliminary investigation of changes in surface micro-topography of minerals colonised by ectomycorrhizal hyphae. Half of the fungal species identified in the forest soil occurred exclusively in the mineral horizons. Mycelial growth, carbon allocation and substrate acidification by fungi colonising different mineral substrates in vitro and in microcosms appeared to be influenced by mineral element composition. Interpretation of possible modification of mineral surface micro-topography is more difficult but together the results obtained suggest that ectomycorrhizal fungi may contribute to the development of microenvironments on colonised mineral surfaces, where increased weathering can take place. Processes regulating nutrient availability in such microenvironments are different from those estimated from the bulk soil solution

AltURI: a thin middleware for simulated robot vision applications

Fast software performance is often the focus when developing real-time vision-based control applications for robot simulators. In this paper we have developed a thin, high performance middleware for USARSim and other simulators designed for real-time vision-based control applications. It includes a fast image server providing images in OpenCV, Matlab or web formats and a simple command/sensor processor. The interface has been tested in USARSim with an Unmanned Aerial Vehicle using two control applications; landing using a reinforcement learning algorithm and altitude control using elementary motion detection. The middleware has been found to be fast enough to control the flying robot as well as very easy to set up and use

Characterization of Phosphate Solubilizing Faba Bean (Vicia faba L.) Nodulating Rhizobia Isolated from Acidic Soils of Wollega, Ethiopia

Some species of rhizobial bacteria nodulating faba bean are characterized by phosphate solubilization. In order to study their in vitro and symbiotic characteristics, twelve rhizobial isolates nodulating faba bean were collected from acidic soil of Wollega, Ethiopia. Solubilization index of the isolates ranges from 1.25 to 2.10. Mean Generation Time of the isolates were less than 2.34; and growth of isolates on Yeast Extract Mannitol agar with bromothymoleblue media were accompanied by change of color from blue to yellow. AUAVR-51 and AUAVR-52 were the highest in TCP-Solubilizion Index. The two isolates were also recognized as stress tolerant when tested in vitro for extreme temperature, osmotic, acidic pH, intrinsic antibiotics, and acidic-aluminum as compared to the other isolates. However, there was no unique metabolic diversity and specialization of AUAVR-51 and AUAVR-52 isolates with respect to carbon and nitrogen source utilization. On the other hand, isolates AUAVR-51 and AUAVR-52 were characterized by effective and highly effective symbiosis on sterile potted sand growth, respectively. In general, phosphate solubilizing rhizobia nodulating faba bean from acidic soil are fast grower; and their solubilization potential varies. However, the contribution of these isolates as double fertilizer should be tested in the real acidic soil characterized by immobilized phosphorous.Keywords: Faba bean Rhizobial isolates Phosphate solubilization Symbiotic effectivenes