The 3-Tier Structured Access Protocol to Control Unfairness in DQDB MANs

This paper addresses the unfairness problem appearing in 802.6-based DQDB MANs. Traffic load demand is characterized as low (below 0.4 of the channel capacity), normal (from 0.4 to 0.9 of the channel capacity) or heavy (greater than 0.9 of the channel capacity). At low loads the 802.6 protocol is acceptably fair. At normal loads, however, the protocol performance is markedly unfair. The unfairness is related to the latency in transporting a request. At heavy loads the unfairness is both latency-related and flooding-related. In this paper, both types of unfairness are carefully analyzed. As a control measure, a 3-Tier Structured Access protocol is proposed. At low loads the 802.6 performance is retained. For normal loads, extra slots are allowed based on predicted demand. At heavy loads access protection is applied. A Dynamic Assessment of Network Topology (DANT) protocol is also presented. The DANT dynamically maintains the additional information required for the implementation of the 3-tier structure. The proposed fair access protocol is studied under different load types and traffic demand. A tuning scheme is proposed to optimized the performance for a particular load environment in real time. The proposed protocol has the potential for dynamic bandwidth allocation and yields satisfactory performance

An Access Protection Solution for Heavy Load Unfairness in DQDB

This paper discusses the unfairness issue arising in a 802.6 DQDB network at high loads-- when the traffic demand to a bus exceeds the capacity of that bus. As per the 802.6 protocol, at heavy loads, the end nodes along a bus experience longer delays than the other nodes. The origin and remedy of this heavy load unfairness is discussed. An access control scheme is proposed as a solution. The comparison of the proposed scheme with 802.6 protocol is presented. The simulation results and performance characteristics are discussed under several types of loads. With symmetric load conditions under the proposed scheme, all active nodes along a bus experience almost the same access delay and packet loss characteristics. Performance under several other load condition are also found to be satisfactory

A Protocol for Dynamic Assessment of Network Topology in DQDB MANs

The 802.6 protocol of DQDB MANs aims to maintain a distributed queue for network access and yet inherits access unfairness. In this paper, the DANT protocol is proposed to provide head-end nodes as well as each active node in a DQDB network with real time information about the active node population, the intermodal distance, the position of each node along what bus and the length of a node\u27s downstream bus segment. DANT\u27s current implementation introduces an overhead of 5 bits per slot but alternative implementations which retain the current slot structure of 802.6 and implement the DANT protocol through the use of periodically issued control slots are possible. Results presented in {3,4,5} show that DANT holds much promise for its use in the context of new load balancing and access protection schemes for DQDB MANs

Characterization and evaluation of morphological and yield traits of tamarind genotypes

The evaluation of morphological and yield traits of tamarind genotypes was carried out during 2017-18 at Forest Research Station, Govinkovi, Honnali taluk, Davangere district. The experiment was laid out in randomized complete block design with 16 genotypes and three replications. Trees were 14-years-old and of grafted origin. All the morphological and yield traits showed significant difference among the selected genotypes indicating the presence of adequate variations. The genotypes recorded morphological variation in terms of tree shape (semi-circle to irregular shape), foliage arrangement (dense to sparse), flowering time (early, mid and late), stem colour (dark brown, brown and light brown), bud colour (greenish white, pink, dark pink), petal colour (yellow and pale yellow), pod colour (greyish brown, brown, light brown and dark brown), pulp colour (light brown, brown and reddish brown), pod shape (straight, slightly curved, curved and deeply curved) and pod size (very big, big, medium and small). The analysis of variance revealed significant difference with respect to tree height, stem girth, pod traits, pod yield per tree (K-9 : 12.80 kg), number of pods per tree (NTI-52 : 989.07) and pulp per cent (K-9 : 48.87). Among the 16 genotypes, the genotype K-9 was found superior with respect to pod size, pod weight, pulp weight and pod yield per tree. Genotype K-9 was found promising and due to perennial in nature further evaluation is required for stability

Dissection of genetic diversity present in eggplant populations using simple sequence repeat markers

Eggplant (Solanum melongena L.) is the third most important solanaceous vegetable and most diversified within species spread across the world-geographical area. A study was conducted to assess the genetic diversity among the selected fifty-four eggplant genotypes (sub-categorized into five sub-population) using twenty-three SSR markers. The Analysis of Molecular Variance among the five sub-population of eggplant revealed the existence of 90.67% variation within populations and 9.34% variation among populations. The SSR markers analysis revealed important locus-wise information like mean Observed-Heterozygosity (0.216), mean Expected-Heterozygosity (0.496), Shannon’s Information Index (0.879), mean number of different alleles (3.209), mean number of effective alleles (2.535), Fixation-Index (0.649). Further, Phylogenetic-analysis clearly categorize genetically distinct individuals in which the most diversified clusters was cluster-1 (C1) out of total of five clusters and especially, wild cultivars were grouped into cluster-5 (C5). The obtained results can be used in eggplant breeding and germplasm conservation in a resourceful manner

Genetic Diversity Analysis and Barcoding in Tuberose (Polianthes tuberosa L.) Cultivars Using RAPD and ISSR Markers

Tuberose is one of the most important bulbous ornamentals grown commercially for loose as well as cut flowers. RAPD and ISSR markers used in the study revealed 53% and 73% polymorphism, respectively, among ten tuberose varieties. Polymorphic Information Content (PIC) and Resolving Power (RP) for RAPD varied from 0.35 - 0.46 and 0.8 - 3.6, respectively, and that for ISSR was 0.36 - 0.49 and 0.91 - 4.55, respectively. The dendrogram (UPGMA), based on Jaccards co-efficient as similarity index for RAPD and ISSR, grouped ten varieties into two major clusters, and, combined RAPD-ISSR cluster analysis formed three major clusters based on their genetic relatedness/variation. PCA revealed that the spatial arrangement of these 10 cultivars was congruent with dendrogram analysis. Mantel's test indicated very good correlation, with r = 0.86 for combination of ISSR and RAPD-ISSR. To facilitate identification of tuberose cultivars, a cultivar identification diagram (CID) was developed in which seven ISSR loci could differentiate all the ten cultivars used in the study. Barcodes were developed for five cultivars released by IIHR using 57 polymorphic loci generated by 11 ISSR primers. The size of these loci ranged from 252bp to 2.2kb. These barcodes can be used as a standard reference source for quick identification of cultivars

Validation of Molecular Markers Genetically Linked to S-Cytoplasm and Restoration-of-fertility (Rf) Loci in Hot Pepper (Capsicum annuum L.)

Existence of CGMS system in hot pepper is due to the rearrangements in the mitochondrial genome and is largely used in economized and pure F 1 hybrid seed production around the world. The orf456, a new ORF present at flanking region of the coxII gene at the 3’ end, was distinguished male sterile cytoplasm in hot peppers along with atp6-2gene. In the current study, eighteen pepper genotypes (nine each of A and corresponding B lines) of varied origin were used to validate with two male sterile cytoplasm (S-cytoplasm) specific sequence characterised amplified region (SCAR) markers viz., atp6-2 (875 bp) and orf456 (456 bp) and one restoration-of-fertility (Rf) locus specific marker, CRF (550 bp). The results clearly showed that the presence of CMS-S-cytoplasm and absence of restoration-of-fertility (Rf) gene in the pepper genotypes studied and is comparable with the phenotypic data. In view of the outcomes it has been reasoned that the accessible S and Rf markers available in the public domain are reproducible and can be promptly utilized for marker assisted selection (MAS) in hot pepper crop improvement program

Striking reduction of amyloid plaque burden in an Alzheimer's mouse model after chronic administration of carmustine

BACKGROUND: Currently available therapies for Alzheimer's disease (AD) do not treat the underlying cause of AD. Anecdotal observations in nursing homes from multiple studies strongly suggest an inverse relationship between cancer and AD. Therefore, we reasoned that oncology drugs may be effective against AD. METHODS: We screened a library of all the FDA-approved oncology drugs and identified bis-chloroethylnitrosourea (BCNU or carmustine) as an effective amyloid beta (Aβ) reducing compound. To quantify Aβ levels, Chinese hamster ovary (CHO) cells stably expressing amyloid precursor protein 751WT (APP751WT) called 7WD10 cells were exposed to different concentrations of BCNU for 48 hours and the conditioned media were collected. To detect Aβ the conditioned media were immunoprecipitated with Ab9 antibody and subjected to immunoblot detection. Amyloid plaques were quantified in the brains of a mouse model of AD after chronic exposure to BCNU by thoflavin S staining. RESULTS: BCNU decreased normalized levels of Aβ starting from 5 μM by 39% (P < 0.05), 10 μM by 51% (P < 0.01) and 20 μM by 63% (P < 0.01) in CHO cells compared to a control group treated with butyl amine, a structural derivative of BCNU. Interestingly, soluble amyloid precursor protein α (sAPPα) levels were increased to 167% (P < 0.01) at 0.5 μM, 186% (P < 0.05) at 1 μM, 204% (P < 0.01) at 5 μM and 152% (P < 0.05) at 10 μM compared to untreated cells. We also tested the effects of 12 structural derivatives of BCNU on Aβ levels, but none of them were as potent as BCNU. BCNU treatment at 5 μM led to an accumulation of immature APP at the cell surface resulting in an increased ratio of surface to total APP by 184% for immature APP, but no change in mature APP. It is also remarkable that BCNU reduced Aβ generation independent of secretases which were not altered up to 40 μM. Interestingly, levels of transforming growth factor beta (TGFβ) were increased at 5 μM (43%, P < 0.05), 10 μM (73%, P < 0.01) and 20 μM (92%, P < 0.001). Most significantly, cell culture results were confirmed in vivo after chronic administration of BCNU at 0.5 mg/kg which led to the reduction of Aβ40 by 75% and amyloid plaque burden by 81%. Conversely, the levels of sAPPα were increased by 45%. CONCLUSIONS: BCNU reduces Aβ generation and plaque burden at non-toxic concentrations possibly through altered intracellular trafficking and processing of APP. Taken together these data provided unequivocal evidence that BCNU is a potent secretase-sparing anti-Aβ drug. See related commentary article here http://www.biomedcentral.com/1741-7015/11/8

Partial joint processing with efficient backhauling using particle swarm optimization

In cellular communication systems with frequency reuse factor of one, user terminals (UT) at the cell-edge are prone to intercell interference. Joint processing is one of the coordinated multipoint transmission techniques proposed to mitigate this interference. In the case of centralized joint processing, the channel state information fed back by the users need to be available at the central coordination node for precoding. The precoding weights (with the user data) need to be available at the corresponding base stations to serve the UTs. These increase the backhaul traffic. In this article, partial joint processing (PJP) is considered as a general framework that allows reducing the amount of required feedback. However, it is difficult to achieve a corresponding reduction on the backhaul related to the precoding weights, when a linear zero forcing beamforming technique is used. In this work, particle swarm optimization is proposed as a tool to design the precoding weights under feedback and backhaul constraints related to PJP. The precoder obtained with the objective of weighted interference minimization allows some multiuser interference in the system, and it is shown to improve the sum rate by 66% compared to a conventional zero forcing approach, for those users experiencing low signal to interference plus noise ratio