Optimal Guaranteed Services Timed Token (OGSTT) Media Access Control (MAC) Protocol for Networks That Support Hard Real-Time and Non Real-Time Traffic

In networks that support real-time traffic and non-real-time traffic over the same physical infrastructure, the challenge to the Media Access Control (MAC) protocol of such network is the ability to support  the different traffic without compromising quality of service (QoS) for any of them. Generally, timed-token MAC protocols group the diverse real-time traffic into one category and then dedicate certain portion of the available bandwidth to them. At the same time, some bandwidth are left unassigned but available to the non real-time traffic. The unassigned bandwidth, and in some cases, the unused bandwidth left by the real-time traffic are assigned to the non-real-time traffic on best effort basis. In this paper, Optimal Guaranteed Services Timed Token (OGSTT) MAC protocol is developed and analyzed. In order to provide better support for both real-time traffic and non-real-time on the same local area network, OGSTT employs the timed-token mechanisms in the Timely-Token protocol along with that of Budget Sharing Token (BuST) protocol. Some bounds on the behavior of OGSTT protocol are discussed along with the ability of OGSTT protocol to support real-time and non-real time traffic. In particular, the paper demonstrated that the performance achieved by OGSTT is better than the Timely-Token and BuST. Furthermore, OGSTT protocol can be incorporated into the Ethernet network to provide real-time performance guarantees to multimedia applications and hard and soft real-time traffic

EMPIRICAL STUDY OF THE CHARACTERISTICS OF AFZELIA AFRICANA SEED UNDER COMPRESSIVE LOADING

Afzelia Africana seeds were subjected to quasi-static parallel plate compression test, using Monsanto Tensometer. The loading orientations were horizontal, vertical and edge-to-edge loading positions at four different moisture content levels of 10.6%, 12.8%, 15.2% and 18.4% wet basis (wb). Slight variations were observed in the means of the physical characteristics at varying moisture content in the range of 10.6% to 18.4%. Loading position was shown to have significant effect on all the mechanical properties studied. The rupture force increased with increase in moisture content in horizontal and vertical loading but did not show consistent trend in variation when loaded on the edges. This value was 155.68N for vertical loading, 139.27 N for horizontal loading and 81.0 N for edge-to-edge loading. Hardness ranged from 6.97 to 6.92 N/mm for horizontal loading, 6.92 to 6.67N/mm for edge-loading and 6.99 to 6.93N/mm for vertical loading respectively in the moisture content range of 10.6 to 18.4% for all cases. Rupture energy varied from 104 to 416.33 N-mm on horizontal loading, 59.96to 241.82 on edge-loading and 190.125 to 419.171 Nmm on vertical loading respectively for the same range of moisture content. Toughness varied from 43.758 to 8.865 N-m/mm, 23.563 to 5.370 and 44.667 to 16.349 N-m/mm for horizontal loading, edge-edge orientation, and vertical loading respectively, for moisture content range of 10.6 to 18.4%.Modulusof Elasticity dropped from 35.657 to 28.133 N/mm2 for horizontal loading, from 51.443 to 14.59 for edge-to-edge loading and 38.087 to 41.04 N/mm2for vertical loading in the range of moisture content of 10.6 to 18.4% respectively. The data generated in this study can be applied when estimating the energy and force needed for shelling the seeds and in making useful suggestions on the loading condition that will demand the least energy for the operation and shelling. The physical properties are also useful in process design and analysis.  http://dx.doi.org/10.4314/njt.v36i3.4

Association between composite scores of domain-specific cognitive functions and regional patterns of atrophy and functional connectivity in the Alzheimer's disease spectrum

Background: Cognitive decline has been found to be associated with gray matter atrophy and disruption of functional neural networks in Alzheimer’s disease (AD) in structural and functional imaging (fMRI) studies. Most previous studies have used single test scores of cognitive performance among monocentric cohorts. However, cognitive domain composite scores could be more reliable than single test scores due to the reduction of measurement error. Adopting a multicentric resting state fMRI (rs-fMRI) and cognitive domain approach, we provide a comprehensive description of the structural and functional correlates of the key cognitive domains of AD. Method: We analyzed MRI, rs-fMRI and cognitive domain score data of 490 participants from an interim baseline release of the multicenter DELCODE study cohort, including 54 people with AD, 86 with Mild Cognitive Impairment (MCI), 175 with Subjective Cognitive Decline (SCD), and 175 Healthy Controls (HC) in the ADspectrum. Resulting cognitive domain composite scores (executive, visuo-spatial, memory, working memory and language) from the DELCODE neuropsychological battery (DELCODE-NP), were previously derived using confirmatory factor analysis. Statistical analyses examined the differences between diagnostic groups, and the association of composite scores with regional atrophy and network-specific functional connectivity among the patient subgroup of SCD, MCI and AD. Result: Cognitive performance, atrophy patterns and functional connectivity significantly differed between diagnostic groups in the AD-spectrum. Regional gray matter atrophy was positively associated with visuospatial and other cognitive impairments among the patient subgroup in the AD-spectrum. Except for the visual network, patterns of network-specific resting-state functional connectivity were positively associated with distinct cognitive impairments among the patient subgroup in the AD-spectrum. Conclusion: Consistent associations between cognitive domain scores and both regional atrophy and networkspecific functional connectivity (except for the visual network), support the utility of a multicentric and cognitive domain approach towards explicating the relationship between imaging markers and cognition in the AD-spectrum

Replacement of soybean meal and maize offal with Bambara groundnut offal in broiler diets

No Abstract.Nigeria Agricultural Journal Vol. 35 2004: pp. 133-14

Effect of finisher diets treated with organic acids on carcass and internal organs of broiler chickens

An experiment was carried out to determine the effect of different organic acids (OAs) on carcass yield and internal organ characteristics of broiler chickens. The OAs were ethanoic acid (acetic acid - AA), butanoic acid (butyric acid - BA), citric acid (CA) and methanoic acid (formic acid - FA). One hundred and fifty (150) day old AborAcre-plus chicks were used. There were five dietary treatments. Diet 1 which served as control (CON) contained no OAs, while 0.25% of AA, BA, CA and FA replaced palm kernel cake in diets 2 – 5. Each treatment was replicated three times with 10 birds per replicate, arranged in completely randomized design (CRD). Diets were both isoenergetic and isonitrogenous. The experiment lasted for 4 weeks during the finisher phase. Feed and water were given ad libitum. At the end of 4 weeks, 3 birds from each replicate giving a total of 9 birds per treatment were slaughtered for carcass and internal organ evaluation. Result from the carcass evaluation showed that dressed carcass, breast, thigh, wing and drumstick of OA treated groups were not significantly (P>0.05) different from the control. The backcut was significantly (P<0.05) heavier in control than in AA and CA. Abdominal fat in birds fed OAs was statistically similar to the control. The liver weight was significantly (P<0.05) reduced by BA and FA while the weight of spleen was reduced (P<0.05) by all the OAs. The caecum and the large intestine were significantly (P<0.05) enlarged in the control. There was non effect (P>0.05) on other internal organs.Keywords: broiler chickens, carcass yield, organic acids, internal organ characteristics