Interactivity And User-heterogeneity In On Demand Broadcast Video

Video-On-Demand (VOD) has appeared as an important technology for many multimedia applications such as news on demand, digital libraries, home entertainment, and distance learning. In its simplest form, delivery of a video stream requires a dedicated channel for each video session. This scheme is very expensive and non-scalable. To preserve server bandwidth, many users can share a channel using multicast. Two types of multicast have been considered. In a non-periodic multicast setting, users make video requests to the server; and it serves them according to some scheduling policy. In a periodic broadcast environment, the server does not wait for service requests. It broadcasts a video cyclically, e.g., a new stream of the same video is started every t seconds. Although, this type of approach does not guarantee true VOD, the worst service latency experienced by any client is less than t seconds. A distinct advantage of this approach is that it can serve a very large community of users using minimal server bandwidth. In VOD System it is desirable to provide the user with the video-cassette-recorder-like (VCR) capabilities such as fast-forwarding a video or jumping to a specific frame. This issue in the broadcast framework is addressed, where each video and its interactive version are broadcast repeatedly on the network. Existing techniques rely on data prefetching as the mechanism to provide this functionality. This approach provides limited usability since the prefetching rate cannot keep up with typical fast-forward speeds. In the same environment, end users might have access to different bandwidth capabilities at different times. Current periodic broadcast schemes, do not take advantage of high-bandwidth capabilities, nor do they adapt to the low-bandwidth limitation of the receivers. A heterogeneous technique is presented that can adapt to a range of receiving bandwidth capability. Given a server bandwidth and a range of different client bandwidths, users employing the proposed technique will choose either to use their full reception bandwidth capability and therefore accessing the video at a very short time, or using part or enough reception bandwidth at the expense of a longer access latency

Study of Different Rates of Application of Pendimethalin and Acetochlor onWeed Infestation and Grain Yield of Fababean

A fababean weed control trial was conducted during the 2016-2017 growing season. The aim of this study is to investigate the effect of two preemergence herbicides Pendimethalin and Acetochlor on weed infestation in a fababean crop. Dominant weed botanical families in the experimental site belong to Asteraceae and Poaceae. Results showed that the improvement of fababean grain yield depends on the weed control efficacy. Treatment with Pendimethalin at 1228 g/ha widely decrease fababean weed infestations recording 91.7% and 90.56 respectively on visual efficacy rating and weed biomass reduction. Acetochlor at 1050 g/ha recorded the lowest efficacies 53.3% and 62.1% respectively on visual efficacy rating and weed biomass reduction. Plots treated with Pendimethalin at 1228 g/ha recorded the best yields with an average of 3.32 tons / ha

Characterization of a single clonal lineage of Fusarium oxysporum f. sp. albedinis causing Bayoud disease of date palm in Morocco

Bayoud, the #Fusarium wilt of date palm, was first detectd in southern Morocco (Draa Valley), after which it spread to most of the Moroccan pal groves. To assess whether the epidemic results from the spread of a single virulent clone, 42 isolats of #Fusarium oxysporum f. sp. #albedinis were collected from several cultivars of wilted palms at different locations in Morocco ; two isolates were included from Algeria, where the disease also occurs. The isolates were tested for vegetative compatibility group (VCG), restriction fragment length polymorphism (RFLP), and random amplified polymorphic DNA (RAPD). No polymorphism was observed either in RFLP studies on mitochondrial DNA or in RAPD analysis, and all strains belonged to a single VCG (0170). Sequences homologous to the DNA transposable element Fot1 were found in the genome of the #F. oxysporum f. sp. #albedinis$strains. Repetitive DNA patterns were produced when EcoRI-digested DNA of the isolates was probed with Fot1 ; 23 distinct hybridization patterns were established among the 44 isolates. Of these patterns, 4 accounted for more than 50$ f. sp. #albedinis strains at a genetic distance of 0.11. Such close genetic relationships between the isolates provides evidence that Moroccan #F. oxysporum f. sp. #albedinis$ populations may belong to a single clonal lineage that originated in Moroccan palm groves and eventually reached the Algerian oases. (Résumé d'auteur

Big data traffic management in vehicular ad-hoc network

Today, the world has experienced a new trend with regard to data system management, traditional database management tools have become outdated and they will no longer be able to process the mass of data generated by different systems, that's why big data is there to process this mass of data to bring out crucial information hidden in this data, and without big data technologies the treatment is very difficult to manage; among the domains that uses big data technologies is vehicular ad-hoc network to manage their voluminous data. In this article, we establish in the first step a method that allow to detect anomalies or accidents within the road and compute the time spent in each road section in real time, which permit us to obtain a database having the estimated time spent in all sections in real time, this will serve us to send to the vehicles the right estimated time of arrival all along their journey and the optimal route to attain their destination. This database is useful to utilize it like inputs for machine learning to predict the places and times where the probability of accidents is higher. The experimental results prove that our method permits us to avoid congestions and apportion the load of vehicles in all roads effectively, also it contributes to road safety

Devil's Thorn (Emex spinosa (L.) Campd.) Response to Tribenuron-methyl and 2,4-D in Ouazzane Region of Morocco

A soft wheat weed control trial was conducted during the 2016-2017 growing season. The aim of this study is to investigate the effect of two postemergence herbicides Tribenuron-methyl and 2,4 D on Emex spinosa infestation in a soft wheat crop. Treatments consist on two Tribenuron-methyl rates of application and two 2,4-D rates of application. The experimental design was a random block with tree repetitions and observations were made 60 days after application of herbicides. Results showed that treatment with Tribenuron-methyl at 9.50g/ha and 14.25g/ha widely decrease E. spinosa infestations. Tribenuron-methyl at 9.50g/ha recorded 87.8%, 86.1% and 90.5% respectively on E. spinosa density reduction, E. spinosa height reduction, and E. spinosa dry biomass reduction. Tribenuron-methyl at 14.25g/ha recorded 96.3%, 95.5% and 98.7% respectively on E. spinosa density reduction, E. spinosa height reduction, and E. spinosa dry biomass reduction. 2,4 D at 400g/ha and 600g/ha recorded the lowest efficacies that did not exceed 75.2% in all observed parameters

Effect of two drying methods on key physicochemical properties and sensory profile of dried figs (Ficus carica L)

In Morocco, the majority of small farmers carry out solar drying of the fruits by traditional process on their farms. Such practice leads to losses in quality and quantity in dried fruits. This study aims to evaluate sensory and physico-chemical quality of dried figs by using two drying methods: (1st) Usual solar drying practiced by farmers and (2nd) Natural convection solar drying using a green solar dryer. The obtained results showed that second method reduced the drying time from 10 days (first method) to 4 days on average. In addition, it was found that the green solar dryer allows an increase in the temperature inside the drying chamber of + 8.1°C, on average, compared to the ambient temperature. Sensory analysis showed that the five assessed attributes (Mouth feel, color, appearance, flesh thickness and texture) were highly appreciated by using natural convection solar drying. The high difference was noted for the "mouth feel" attribute, followed by "color" which are the two main aspects searched by consumers. Regarding physico-chemical properties, solar-dried figs are rich with citric acid (12.0 g/l vs 9.72 g/l) and in total soluble sugars (60.6% vs 56.0%) compared to sun-dried figs. The water activity was respectively 0.631 and 0.672 for the 1st and 2nd method. In general terms, farmers are encouraged to enhance their drying methods by using natural convection solar drying as a preservative method that maintain nutritional and sensory quality of dried figs. Keywords: Figs, Quality, Sensory, Physico-chemical, Morocco, solar drying prototyp

Recherche d’un milieu synthétique pour la croissance et la toxicogenèse des Aspergillus du groupe flavus

Jacquet Jean, Tantaoui Elaraki Abdelrhani. Recherche d’un milieu synthétique pour la croissance et la toxicogenèse des Aspergillus du groupe flavus. In: Bulletin de l'Académie Vétérinaire de France tome 128 n°9-10, 1975. pp. 457-466

Vegetative compatibility and pathogenicity of Verticillum dahliae isolates from olive (Olea europea)

Vegetative compatibility, determined by pairing auxotrophic mutants that are unable to utilize mineral nitrogen, was studied by means of 44 isolates of Verticillium dahliae Kleb. Thirty-seven isolates were collected from olive in the main areas in Morocco, 3 from Algerian olives, 2 from tomato, 1 from aubergine and 1 from olive-grove soil where Verticillium wilt was present. Approximately 475 mutants were used, allowing assignment of 34 isolates to 3 vegetative compatibility groups (VCGs). The VCGs of the remaining 10 isolates were not defined. The pathogenicity of ten isolates was assessed by inoculating olive plants with suspensions of conidia at 105 conidia ml-1. Highly significant differences in the pathogenic ability of the ten isolates were recorded. No relationship was found between VCGs and pathogenicity of isolates