Dynamic-Threshold-Limited Timed-Token (DTLTT) Protocol

An improved version of the Static-Threshold-Limited On-Demand Guaranteed Service Timed-Token (STOGSTT) Media Access Control (MAC) protocol for channel capacity allocation to the asynchronous trac in Multiservice Local Area Network (MLANs) was developed and analyzed. TLODGSTT protocol uses static value of threshold bandwidth to allocate available bandwidth to the asynchronous trac, as such, the throughput of STLODGSTT protocol drops signi cantly under non-uniform heavy load of asynchronous trac. The DTLTT protocol dynamically adjusts the threshold bandwidth in response to the variations in the load distribution of the asynchronous trac. In view of this dynamic mechanism, under various load distributions of the asynchronous trac, the DTLTT protocol maintains higher throughput than the STLODGSTT protocol. The improvement is demonstrated through analytical computations and simulation results.Keywords: multi-access, multiservice, network, synchronous, asynchronous, trac, timed-toke

Computer Aided Design Of The Magnetic Circuit Of A 3- Phase Power Transformer

In this paper, a computer program was developed in C++ language to determine the parameters of the magnetic circuit of a three-phase power transformer. A typical case study was used to demonstrate the effectiveness of the program. The program was developed using the mathematical models derived for the parameters to be determined, Apart from being flexible and speedy, the program removed the drudgery involved in the design and demonstrated the usefulness of software as both a teaching and research aid. Tables and graphs obtained from the program showed how the design problems were dealt with and how the parameters of the magnetic circuit were determined

SIMULATION AND ANALYSIS OF PENTOSE PHOSPHATE PATHWAY IN PLASMODIUM FALCIPARUM USING COLORED PETRI NETS MODEL

Plasmodium falciparum is a protozoan parasite and the deadliest of five human malaria species which is responsible for the majority of malaria related deaths in humans. The erythrocytes’ stage of Plasmodium falciparum depend on Pentose Pathway as an alternative source of energy and it releases electrons used in protecting the Plasmodium falciparum from its host. Colored Petri Net has been recognized as one of the important models in modelling and analyzing biological pathways. It is an accurate qualitative and quantitative modelling tool for modeling complex biological systems. In this work, the modeling of the pentose phosphate pathway in Plasmodium falciparum is presented using the Petri Net Markup Language (PNML). The Colored Petri Net (CPN) models based on the Petri Net representation and the conservation and kinetic equations were used to examine the dynamic behavior of the metabolic pathway. The usefulness of Petri Nets is demonstrated for the quantitative analysis of the pathway. We obtained data from Biocyc database. The constructed model was viewed through the Colored Petri Net Tool (CPN tool 4.0). Specific drug targets called the essential reactions within the pathway were identified, listed and proposed. These essential reactions would alter the functioning of the pathway which would affect the energy and protection needs of the parasite therefore leading to the death of the parasite in the human red blood cell

Length-weight relationship and condition factor of clarias gariepinus and tilapia zillii in lake alau and monguno hatchery,

Length-Weight relationship and condition factor of Clarias gariepinus and Tilapia Zillii were studiedin lake Alau and Monguno hatchery, both in Borno State of Nigeria, for a period of two weeks. A total of 98 C. gariepinus and 140. T. zillii were measured. The length-weight regression coefficient (b) for both fishes in lake Alau were not significantly different from the hypothesized value 3, but for both fishes in Monguno hatchery (b) differed signifcantly from the hypotheszed value. Isometric growth of both fshes was recorded in lake Alau while a comparative decline in weight in relation to specific length of fishes was recordedin Monguno hatchery. Furthermore, condition of C.gareipinus in lake Alau revealed that all size groups of the fsh grew better than those in Monguno hatchery, while the condiion of T. zillii in Monguno hatchery was better than that in lake Alau. Although our results suggest that C. gariepinus in lake Alau grew faster than that cultured in Monguno hatchery, the study is not conclusive as abiotic, biotic, and sampling error might have interplayed. The reverse is also true for the growthpotentials of T. zillii in Monguno hatchery whencompared to that in lake Aau. Keywords: Clarias gariepinus, Tilapia zillii, lake, Hatchery pond Animal Research International Vol. 4 (1) 2007 pp. 635-63

Overview of human and animal brucellosis in Nigeria and its economic impacts on production

Brucellosis is a wide spread zoonotic bacterial disease of humans and animals. In humans the disease is recognized commonly as undulant fever, characterized by headache malaise, and arthritis. Brucellosis can occur in any age group, but mainly found in young men between the ages of 20 and 40 years because of occupational hazards. Domestic animals (cattle, sheep and goat, pigs, dogs etc) are highly susceptible to brucellosis.  Generally, brucellosis manifest in female animals as abortion, retained placenta, stillbirth and death of young ones soon after birth. In males, the  main features are vesiculitis, orchitis, and epididymitis, which may render infected male infertile for life. The endemicity of brucellosis has remained  a threat in low- income countries of sub-Saharan Africa and South Asia and has multiple economic implications across agriculture and public health  sectors, and broader implications on economic and social development sectors. Google and Google Scholar were used to retrieve articles used for  this review, which included published research articles and local, national and international reports on brucellosis. In this review, we summarised  human and animal brucellosis, prevalence of infections in Nigeria, and economic impacts on production. It is believed that this review will guide  researchers on the state of brucellosis in developing countries where the disease is still endemic, using Nigeria as a case study

CHEMICAL PROPERTIES OF FOAM MAT-DRIED TOMATO POWDER AS AFFECTED BY PROCESS VARIABLES

This research aimed at studying the optimization of process variables for the production of quality foam mat-dried tomato. The method of drying used for this study is foam mat drying and oven drying which serves as the control.  For this study, Box-Behnken experimental design of response surface methodology (RSM) was used for designing the experiments. The independent variables selected for the foam mat drying were acacia gum (1 - 3 %) as foam stabilizer, temperature (60 -80 oC) and weight of tomato pulp (170, 190 and 210 g/m2). While for the controls were just dried at different temperature ranges of 60, 70 and 80 oC. The fresh ripe tomato was washed, desked, cut into smaller pieces, pulped before adding the foaming agent and stabilizer then whipped for 7 min and dried in a rectangular tray at 60, 70, 80 oC, scarped, milled and packaged in air tight container. Lycopene, total sugar, ascorbic acid, beta-carotene, and total soluble solids ranged from 2.87 – 11.80 mg/100g, 0.0002 – 0.0012 mml/L, 121.01 – 127.50 mgL-1, 1.40 – 2.47 mg, 4.60 – 7.27oBrix respectively and their controls ranged from 6.79 – 9.26 mg/100g, 0.0001 – 0.0008 mml/L, 60.13- 70.81 mgL-1, 0.56 – 0.83 mg and 0.80 – 1.60oBrix respectively. Keywords: Foam Mat Dried Tomato Powder; Process Variables; Chemical Properties; Lycopene; Correlation; Optimization; Face Centered Composite Design. DOI: 10.7176/FSQM/121-06 Publication date: April 30th 2023  

Detection and phenotypic characterization of methicillin-resistant Staphylococcus aureus from clinical and community samples in Abakaliki, Ebonyi State, Nigeria

Objective: The objective of this study was to isolate and phenotypically characterize methicillin-resistant Staphylococcus aureus (MRSA)from clinical and community samples in Abakaliki, Nigeria.Methods: A total of 709 clinical (303) and community samples (406) samples were obtained for this study. MRSA isolates were detected using Kirby-Bauer disc diffusion method with the inclusion of 1 μg oxacillin and cefoxitin antibiotic disc. The isolates were screened for the β-lactamase production using nitrocefin sticks.Results: A total of 44 MRSA isolates were obtained from the samples with prevalence frequency of 22.6 % and 20.8 % from clinical and community samples respectively. The clinical isolates were completely resistant (100 %) to ceftazidime, tetracycline and penicillin. Gentamicin and ciprofloxacin were the most effective antibiotics against the clinical and community isolates respectively with a susceptibility frequency of 63.2 % and 80 %. Exactly 38.1 % and 24.2 % of the clinical and community S. aureus isolates were positive for beta-lactamase production respectively. The HA-MRSA and CA-MRSA isolates had MARI valueswithin the range of 0.3 to 1.0.Conclusion: This present findings of multi-drug resistance MRSA is very worrisome as it further highlights the pressing need to keep a strict watch on MRSA emerging from this study area.Keywords: MRSA, beta-lactamase, antibiotics, multidrug resistance, clinical samples, community samples