The Performance Evaluation of Adaptive Guard Channel Scheme in Wireless Network

Dynamic Guard Channels (DCG) reduces the dropping and blocking rates in a network. However, most of the existing DGC allocations are not quite efficient because there were consideration for only the Handoff (HO) calls while the New calls (NC) were not considered; this leads to poor Quality of Service (QoS) for NC. Although it is better to give priority to HO calls over NC since the breaking of the connection of an established communicationis more annoying than blocking a NC. Thus, there is need to provide an alternative approach that guarantees an acceptable QoS in terms of both the HC and the NC. This paper presents the performance evaluation of an adaptive guard channel allocation; the scheme made use of two different models (1) guard channel with fuzzy logic (2) guard channel without fuzzy logic. Priority is given to handoff call due to the scarcity of radio spectrum. When all the guard channels have been allocated and the arrival rate of handoff calls keeps on increasing, new set of threshold values would be estimated by fuzzy logic model. Performance metrics are; Call Blocking Rate (CBR), Call Dropping Rate (CDR) and Throughput. Results showed that guard channel with fuzzy logic has the CBR values range from 24.02% to 69.015 and CDR values range from 12.025 to 18.90% while guard channel without fuzzy logic has CBR values range from 28.22% to 75.65% and CDR values range from 19.06% to 36.50%. The scheme proved to be more efficient in congestion control in wireless network

Chemical compositions of Casuarina equisetifolia L., Eucalyptus toreliana L. and Ficus elastica Roxb. ex Hornem cultivated in Nigeria

AbstractEssential oils were obtained by separate hydrodistillation of three different plants cultivated in Nigeria and analysed comprehensively for their constituents by means of gas chromatography (GC) and gas chromatography-mass spectrometry (GC–MS). The leaf essential oil of Casuarina equisetifolia L. (Casuarinaceae) comprised mainly of pentadecanal (32.0%) and 1,8-cineole (13.1%), with significant amounts of apiole (7.2%), α-phellandrene (7.0%) and α-terpinene (6.9%), while the fruit oil was dominated by caryophyllene-oxide (11.7%), trans-linalool oxide (11.5%), 1,8-cineole (9.7%), α-terpineol (8.8%) and α-pinene (8.5%). On the other hand, 1,8-cineole (39.4%) and α-terpinyl acetate (10.7%) occurred in large quantities in the essential oils of the leaf of Eucalyptus toreliana L. (Myrtaceae). The oil also features high levels of sabinene (5.9%), caryophyllene-oxide (4.7%) and α-pinene (4.2%). The main compounds identified in the leaf oil of Ficus elastica Roxb. ex Hornem. (Moraceae) were 6,10,14-trimethyl-2-pentadecanone (25.9%), geranyl acetone (9.9%), heneicosene (8.4%) and 1,8-cineole (8.2%)

Occurrence of parasite eggs and oocysts in commonly consumed vegetables collected from selected markets in Zaria, Kaduna State Nigeria

A study was conducted with the objective of determining the occurrence of parasite eggs and oocysts in washed and unwashed vegetables sold in some selected markets in Zaria, Kaduna State. Cabbage (Brassica oleracea), Tomato (Lycopersicon esculentum), Lettuce (Lactuca sativa), Carrot (Daucus carota) and Spinach (Spinacea oleracea) were collected based on convenient sampling from 5 markets. Three hundred grams of each vegetable was purchased every week in the morning hours from each of the selected markets during the rainy and dry seasons. Floatation technique was used for processing of the vegetable samples. Unwashed vegetables (269) had more parasite eggs and oocysts than washed vegetables (209). Spinach (52.50%) had the highest contamination, followed by carrot (48.75%), cabbage (42.50%), lettuce (40.0%) and tomatoes (28.75%). There was a significant (p < 0.05) association between the occurrence of parasite eggs and oocysts and the washing of vegetables. Among the unwashed vegetables, lettuce was highly contaminated (58.75%) with parasite eggs and oocysts, followed by spinach (55.0%), carrot (55.0%), tomatoes (50.0%) and cabbage (39.75%). There was, however, no significant (p > 0.05) association between the occurrence of parasite eggs and oocysts and the unwashed vegetables. Among the different markets, vegetables purchased from Dan Magaji market (51.25%) were highly contaminated, followed by Tudun Wada (49.38%), Sabongari (48.75%), Zaria city (48.75%) and Samaru market (41.88%).There was, however, no significant (p > 0.05) association between the occurrence of parasite eggs and oocysts on vegetables and the markets where the vegetables were purchased. The study showed that eggs and oocysts of various parasites mainly of human and animal faecal origin were present on vegetables marketed for human consumption even after washing. Therefore, people should properly wash their vegetables before consumption and indiscriminate defecation should be discouraged to prevent contamination and improve hygienic conditions.Keywords: Eggs, Oocyst, Market, Parasite, Vegetable, Zari

Effects of N-Butanol and Aqueous Fractions of Khaya senegalensis, Guiera senegalensis and Tamarindus Indica Leaves Extracts on Eimeria tenella Oocyst Sporulation in Vitro

The in vitro anti coccidial activities of n-butanol and aqueous fractions of Khaya senegalensis, Gueira senegalensis and Tamarindus indica leaves extracts on Eimeria tenella parasite was studied by observing the effects of the plant extracts on the sporulation of the Eimeria tenella oocysts. Drug resistance and consumer demanding decrease in the use of drugs in animals have generated interest in alternative strategies to control the avian disease one of which is herbal intervention studies. Fresh faecal samples were collected from infected birds and their oocysts load determined. Dilutions of the extracts (100mg, 250mg, 400mg, 550mg, 700mg and 850mg per ml) in distilled water were prepared and placed in separate well labelled petri dishes. 100 oocysts were added to each petri dish and the set up was left at ambient temperature on the laboratory table and monitored twice daily (9.00am and 3.00pm) to observe the sporulation of the oocysts over a 72 hours period. Laboratory sporulation medium (2.5% Potassium dichromate) and Amprolium were used for comparison. The phytochemical result implied that the active ingredients were present mainly in the n-butanol and crude extract  fractions with the nbutanol fraction of the Khaya senegalensis extract containing phenols and flavonoids which have antioxidant effects. The in vitro study showed that the n-butanol fraction of K senegalensis (100mg/ml) and the aqueous fraction of Tamarindus indica (100mg/ml) extracts had similar effects to those obtained using Amprolium which was considered as the standard by inhibiting the sporulation of Eimeria tenella oocysts. It is therefore recommended that more work needs to be done to determine the anti  coccidial activities of these extracts in vivo. Key words: Eimeria tenella, sporulation, in vitro, extract

Cryptic Eimeria genotypes are common across the southern but not northern hemisphere

The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Developments in the formulation and application of vegetable oil-based metalworking fluids in turning process

In the beginning, metalworking fluids consisted of simple oils applied with brushes to lubricate and cool the machine tool. As cutting operations became more severe, metalworking fluid formulation became more complex. There are now several types of metalworking fluids in the market and the most common can be broadly categorized as cutting oils or water-miscible fluids. In this paper, attention is focused on recent research work on formulation and application of vegetable oil-based metalworking fluids in turning process. In addition, the performances of various vegetable oil-based metalworking fluids based on some process parameters such as thrust force, surface roughness, temperature developed at the tool chip interface, and tool wear during turning process using different tool materials were highlighted

ECONOMIC ANALYSIS OF SORGHUM/SOYABEAN INTERCROP SYSTEMS BY PARTIAL BUDGET IN THE GUINEA SAVANNAH OF NIGERIA

International audienceFive sorghum/soyabean planting schedules intercrop were evaluated in a field experiment at Mokwa (Guinea savannah) in Nigeria, during the 2012 and 2013 cropping seasons with a view of determining the planting schedule that will result in the highest net benefits. Experimental design was randomize complete block (RCB) with three replicates. Soyabean variety TGX1019-2EB was drilled on the crest of the ridge, while sorghum seedlings were transplanted on the lower side of the ridge. The following sorghum/soyabean intercrop treatments were evaluated: (1) Sorg + Soy 0DAPS: Sorghum seedlings intercropped with soyabean at 0 day after planting soyabean, (2) Sorg + Soy 14DAPS: Sorghum seedlings intercropped with soyabean at 14 days after planting soyabean, (3) Sorg + Soy 28DAPS: Sorghum seedlings intercropped with soyabean at 28 days after planting soyabean. Sole soyabean and sole sorghum were also planted as treatments 4 and 5 respectively. Results obtained indicated that the treatment Sorg + Soy 0DAPS gave the highest net benefit of N798, 000 and N287, 150 in 2012 and 2013 respectively

In Vivo Efficacy of Momordic Charantia Leaves Extract against Rats Infected with Trypanosome Brucei Brucei (Federe Strain

In vivo study was conducted using thirty adult male rats which were randomly divided into six groups of five rats each. Groups A, B, C, D and E were infected with 1 × 106 of Trypanosomes; Group F was neither treated nor infected. Methanolic leaf extract of Momordica charantia was administered intraperitoneally to rats in groups B, C, D, and E at doses of 100, 200, 500 and 1000 mg/kg body weight, respectively. The groups treated with the extract showed a significant (p0.05) different. Whereas groups B and C were significantly different (p<0.05) and group A was highly significant (p<0.01)