Nonlinear ion-acoustic (IA) waves driven in a cylindrically symmetric flow

By employing a self-similar, two-fluid MHD model in a cylindrical geometry, we study the features of nonlinear ion-acoustic (IA) waves which propagate in the direction of external magnetic field lines in space plasmas. Numerical calculations not only expose the well-known three shapes of nonlinear structures (sinusoidal, sawtooth, and spiky or bipolar) which are observed by numerous satellites and simulated by models in a Cartesian geometry, but also illustrate new results, such as, two reversely propagating nonlinear waves, density dips and humps, diverging and converging electric shocks, etc. A case study on Cluster satellite data is also introduced.Comment: accepted by AS

Semen quality of Yankasa rams

Presents results of a study carried out to determine the ejaculate characteristics of Yankasa rams in Nigeria. Three rams of proven fertility from the breeding herd at shika, of average age of 29 months were investigated. Ejaculates collected during the wet season had higher volume, pH, sperm motility and percentage of normal sperms than those collected in the dry season. Differences between rams were insignificant for all traits except ejaculate volume and sperm motility. The average sperm output per ejaculate was 2.558 x 109 spermatozoa, sufficient to inseminate between 5 and 20 ewes depending on condition of storage. Yankasa rams produced semen which compared favourably in terms of total sperm output per ejaculate and qualitative traits to values for semen of better known temperate breeds of sheep. The observed differences did not appear severe enough as to prevent all year round breeding

Gastrointestinal parasites of bile and faeces of slaughtered cattle and sheep from Maiduguri Municipal Abattoir, North Eastern Nigeria

The occurrence and types of gastrointestinal parasites of bile and faeces of cattle and sheep from the semi-arid region of Maiduguri, North-Eastern Nigeria were determined using standard parasitological techniques. Samples of bile and faeces collected from three hundred and eighty seven (387) cattle and 389 sheep were analysed using bile sedimentation, faecal sedimentation and faecal floatation. An overall prevalence of 42.63% was found in cattle, while 49.36% was in sheep. Results from both species did not vary significantly (p>0.05) based on the sexes, ages and breeds except in sheep, where adult animals were significantly (p˂0.05) infected than the young sheep. Furthermore, 91(23.51%), 13(3.35%) and 84(21.70%) cattle and 15(3.85%), 22(5.65%) and 183(47.04) sheep were positive for one parasite or the other using the bile sedimentation, faecal sedimentation and faecal floatation techniques respectively. In cattle, Fasciola spp was the most predominant parasite recovered with 75(39.89%), followed by strongyle 66(35.11%), Dicrocoelium hospes 23(12.23%) and coccidia 21(11.17%). One animal in each case was infected with Paramphistomum spp. 1(0.53%), and Toxocara vitulorum 1(0.53%). In sheep, Fasciola spp. 24(9.44%), Dicrocoelium hospes 4(1.57%), Paramphistomum spp. 5(1.97), strongyle 75(29.53%), coccidia 140(55.12%), mite egg 1(0.39%), Strongyloides papillosus 2(0.79%) and Moniezia expansa 3(1.18%) were found. Co-infection of two or three parasites in both cattle and sheep was observed with strongyle/coccidia combination being the most frequent. The recovery of parasites of economic and public health significance such as Fasciola spp, Toxocara vitulorum and Strongyloides papillosus indicates that they are abundant and that attention need to be given to their control under ruminant production system. In all, the study had shown the common gastrointestinal parasites found in the study location.Keywords: Prevalence, Maiduguri, Cattle, Sheep, Parasit

Antimicrobial Effects of Acacia nilotica and Vitex doniana on the Thermophilic Campylobacter Species

This study was carried out to investigate the in vitro activity of the extracts of Acacia nilotica and Vitex doniana against Campylobacter jejuni, C. coli, and C. laridis isolated from sheep in Zaria and Kaduna. Water and ethanol crude extracts of Acacia nilotica and Vitex doniana were tested on the thermophilic Campylobacter species. The results obtained show that ethanol extract of Acacia nilotica had minimal inhibition concentration (MIC) of 80 mg/ml, while water extract of the same plant gave an MIC of 250mg/ml. However, ethanol extracts of Vitex doniana had no inhibitory effects on the Campylobacter species tested. A. nilotica and Vitex doniana were used at concentrations ranging from 2 to 200mg/ml of the extracts. Ethanol extract of A. nilotica at concentration of 200mg/ ml and 20mg/ml had inhibitory diameters zone of 6mm and 4mm respectively. Water extract of the same plant at concentrations of 200mg and 20mg had diameters of only 2mm and 1 mm respectively. There was very little or no inhibitions with Vitex doniana water and ethanol extracts. The emergence of Campylobacter strains resistant to most common antibiotics highlights the need to explore new methods for therapeutics against Campylobacter infections. This study has demonstrated that extracts of Acacia nilotica show antibacterial activities against Campylobacter species isolated from sheep in Zaria and Kaduna. (Af. J. of Science and Technology: 2002 3(2): 9-13

New tool for the discrimination between Fasciola hepatica and Fasciola gigantica flukes collected from domestic ruminants

Trabajo presentado al: JOINT COMBAR - ACSRPC meeting: Anthelmintic Resistance in Ruminants: Who cares? Abstract Book, Poster Presentations, pp. 41. Gante (Bélgica). 27-29 agosto 2019.Fascioliosis is a food­borne trematode infection caused by the liver flukes Fasciola hepatica and Fasciola gigantica. This disease is considered a zoonosis, mainly infecting wild and domestic ruminants, causing a considerable socio­economic impact in endemic countries. Traditionally, the distinction between these two species has been based on morphological criterial, although accurate recognition of the two flukes is usually difficult because of substantial variations in the morphological features. Therefore, the main objective of this study was to develop a PCR­based assay for discrimination between F. hepatica and F. gigantica flukes collected in sheep and cattle from Nigeria. A total of 47 animals, 33 cattle and 14 sheep, were sampled and a single adult fluke was collected from each anima.l DNA was extracted from flukes and primers were designed based on mitochondrial DNA sequnces to amplify a 304 bp fragment for the identification of F. hepatica and 752 bp for F. gigantica. Moreover, PCR products from 12 flukes were sequenced for phylogenetic analysis. Out of 47 flukes, 39 were identified as F. hepatica and 18 as F. gigantica. Within each host the percentage of each fluke species was as follows: in cattle 18/33 (54.5%) and 15/33 (45.5%) were F. hepatica and F. gigantica, respectively, and in sheep 11/14 (78.6%) and 3/14 (21.4%). The phylogenetic analysis confirmed these results. Although the number of flukes collected in sheep was limited, it seems that F. hepatica is more prevalent in sheep than F. gigantica; whereas the percentage of each species was similar in cattle. To the best of our knowledge, this is the first study which confirms the presence of F. hepatica in Nigeria