Traditional butter making in Ethiopia and possible improvements

Summarises the results of a study on the traditional methods of butter making-conducted to determine the efficiency of the process and the quality of butter produced. Reports on initial experiments carried out to devise improved methods of butter making

Economic analysis of alternative systems for sorghum production in southern Mali.

United States Agency for International Developmen

Study on the prevalence of bovine fasciolosis in and around Bahir Dar, Ethiopia

A cross sectional study aimed at determining the prevalence and type of common Fasciola species in cattle was conducted in and around Bahir Dar from November 2008- March 2009. The study was based on post-mortem inspection of livers of slaughtered animals at Bahir Dar municipality abattoir and coprological examination using sedimentation technique on fecal samples collected from animals of Bahir Dar and surrounding areas. Out of 413 livers inspected, 165 (39.95%) were positive for Fasciola species. F. hepatica was found to be the most prevalent species in cattle of the study area (89.70%). About 3.63% were positive for F. gigantica and 6.67% were harboring mixed infections. Likewise, out of 384 fecal samples examined 141 (36.72) were positive for the presence of Fasciola eggs. Risk factors such as locality, body condition and sex didn’t show any effect on the prevalence of infections (P>0.05). However, breed and age group revealed significant disparity (P<0.05) as greater magnitude of infections were detected in exotic breed and young age group, respectively. In view of the current result, fasciolosis could be considered as a major problem in Bahir Dar and surrounding areas as the ecological factors and management conditions are suitable both for the snail intermediate host and the parasite to be maintained. Strategic treatments need to be implemented at appropriate timing with the aim of reducing worm burden from infected animals and preclude pasture contamination. Integrated control approaches involving livestock owners has to be implemented in reducing the population and activity of snail intermediate hosts to enable maximization of long-term returns from such endemic areas.Key words: Abattoir, Bovine, Bahir Dar, Coprology, Fasciola, Prevalence

Thermally induced directed currents in hard rod systems

We study the non equilibrium statistical properties of a one dimensional hard-rod fluid undergoing collisions and subject to a spatially non uniform Gaussian heat-bath and periodic potential. The system is able to sustain finite currents when the spatially inhomogeneous heat-bath and the periodic potential profile display an appropriate relative phase shift, $\phi$. By comparison with the collisionless limit, we determine the conditions for the most efficient transport among inelastic, elastic and non interacting rods. We show that the situation is complex as, depending on shape of the temperature profile, the current of one system may outperform the others.Comment: 5 pages, 2 figure

Relaxation oscillations and negative strain rate sensitivity in the Portevin - Le Chatelier effect

A characteristic feature of the Portevin - Le Chatelier effect or the jerky flow is the stick-slip nature of stress-strain curves which is believed to result from the negative strain rate dependence of the flow stress. The latter is assumed to result from the competition of a few relevant time scales controlling the dynamics of jerky flow. We address the issue of time scales and its connection to the negative strain rate sensitivity of the flow stress within the framework of a model for the jerky flow which is known to reproduce several experimentally observed features including the negative strain rate sensitivity of the flow stress. We attempt to understand the above issues by analyzing the geometry of the slow manifold underlying the relaxational oscillations in the model. We show that the nature of the relaxational oscillations is a result of the atypical bent geometry of the slow manifold. The analysis of the slow manifold structure helps us to understand the time scales operating in different regions of the slow manifold. Using this information we are able to establish connection with the strain rate sensitivity of the flow stress. The analysis also helps us to provide a proper dynamical interpretation for the negative branch of the strain rate sensitivity.Comment: 7 figures, To appear in Phys. Rev.

Bethune round table 2012: 12th annual conference: filling the gap

Background: Our aim was to highlight the impact of collaboration between 2 linked tertiary hospitals in Nigeria and India. Methods: We conducted a review of a collaboration between the Amrita Institute of Medical Sciences and Research Centre (AIMS), Kochi, India, and the University of Ilorin Teaching Hospital (UITH), Ilorin, Nigeria, to exchange personnel for the purpose of further training from August 2007 and December 2011. Results: One neurosurgeon, 2 pediatric surgeons and 1 orthopedic surgeon had additional exposure at AIMS for periods of 3 months to 1 year. Four neurosurgery and 3 pediatric surgery perioperative nurses have also been trained at AIMS for periods of 3 months. A pediatric surgeon was invited as faculty for laparoscopic training at Ilorin in 2010. The collaboration has resulted in exposure to surgical procedures not usually done in our centre. Our pediatric surgery unit has commenced laparoscopic surgery and pyeloplasty for pelvic ureteric junction obstruction in children. The orthopedic surgeon has commenced interlocking nailing and joint replacement. The neurosurgeon has successful done endoscopic third ventriculostomy and microscopic resection of brain tumour. Conclusion: This international collaboration has led to capacity building with significant impact on surgical services at UITH. An international collaboration and exchange program is a feasible and desirable strategy for technology transfer between technology-advanced settings and resource-constrained centres

Space-time analysis of reaction at RHIC

Space-time information about the Au-Au collisions produced at RHIC are key tools to understand the evolution of the system and especially assess the presence of collective behaviors. Using a parameterization of the system's final state relying on collective expansion, we show that pion source radii can be tied together with transverse mass spectra and elliptic flow within the same framework. The consistency between these different measures provide a solid ground to understand the characteristics of collective flow and especially the possible peculiar behavior of particles such as Xi, Omega or phi. The validity of the short time scales that are extracted from fits to the pion source size is also addressed. The wealth of new data that will soon be available from Au-Au collisions at sqrt{s_{NN}} = 200 GeV, will provide a stringet test of the space-time analysis framework developped in these proceedings.Comment: Invited talk given at the SQM2003 conference (March 2003), to be published in Journal of Physics G. 10 pages, 3 figure

Rapidity and centrality dependence of particle production for identified hadrons in Cu+Cu collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

The BRAHMS collaboration has measured transverse momentum spectra of pions, kaons, protons and antiprotons at rapidities 0 and 3 for Cu+Cu collisions at $\sqrt{s_{NN}} = 200$ GeV. As the collisions become more central the collective radial flow increases while the temperature of kinetic freeze-out decreases. The temperature is lower and the radial flow weaker at forward rapidity. Pion and kaon yields with transverse momenta between 1.5 and 2.5 GeV/c are suppressed for central collisions relative to scaled $p+p$ collisions. This suppression, which increases as the collisions become more central is consistent with jet quenching models and is also present with comparable magnitude at forward rapidity. At such rapidities initial state effects may also be present and persistence of the meson suppression to high rapidity may reflect a combination of jet quenching and nuclear shadowing. The ratio of protons to mesons increases as the collisions become more central and is largest at forward rapidities.Comment: 19 pages, 11 figures and 6 table

Rapidity dependence of deuteron production in Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV

We have measured the distributions of protons and deuterons produced in high energy heavy ion Au+Au collisions at RHIC over a very wide range of transverse and longitudinal momentum. Near mid-rapidity we have also measured the distribution of anti-protons and anti-deuterons. We present our results in the context of coalescence models. In particular we extract the "volume of homogeneity" and the average phase-space density for protons and anti-protons. Near central rapidity the coalescence parameter $B_2(p_T)$ and the space averaged phase-space density $(p_T)$ are very similar for both protons and anti-protons. For protons we see little variation of either $B_2(p_T)$ or the space averaged phase-space density as the rapidity increases from 0 to 3. However both these quantities depend strongly on $p_T$ at all rapidities. These results are in contrast to lower energy data where the proton and anti-proton phase-space densities are different at $y$=0 and both $B_2$ and $f$ depend strongly on rapidity.Comment: Document updated after proofs received from PR

Phosphorus export from two contrasting rural watersheds in the (sub) humid Ethiopian highlands

Establishing worldwide sustainable and phosphorus efficient cropping systems is urgently needed because the supply of suitable phosphate rock is limited, and excess phosphorus in streams causes eutrophication. One of the impediments in the developing world for sustainable P practices is the lack of studies on P transport and its eventual disposition in the environment. One of these regions with few studies is the Ethiopian Highlands, with permeable volcanic soils. The objective was to establish baseline data on P watershed export in the (sub)humid highlands. Two contrasting watersheds were selected near Lake Tana. For 2 years, stream discharge and sediment, total P, dissolved P, and bioavailable particulate P concentrations were determined at the watershed outlet. The first watershed is the 57 km2 Dangishta, with lava intrusion dikes, forcing subsurface flow through faults to the surface and preventing gully formation. Subsurface flow was half of the 1745 mm annual precipitation, and surface runoff and erosion were minimal. The second watershed is the 9 km2 Robit Bata with 1,420 mm precipitation. The banks of several river banks were slumping. The upper part of the watershed generates saturation excess runoff. A hillslope aquifer in the lower part provided interflow. The average sediment concentrations of 10.5 g L−1 in the stream in Robit Bata (11 times that in Dangishta) reflected the sediments from banks slipping in the stream. The hydrology and the soil loss directly affected the phosphorus export. In Dangishta, the total P concentration averaged 0.5 mg L−1 at the outlet. In Robit Bata, the average total P concentration was 2 mg L−1. The bioavailable particulate P concentration was only twice the concentration in the runoff water. The low phosphorus content of the subsoil slipping in Robit Bata moderated biologically available particulate P at the outlet. Average dissolved P concentrations for both watersheds were around 0.1 mg L−1 in the low range found in temperate climates. It reflects the difference in length of time that phosphorus fertilizers have been applied. Our research concludes that commonly implemented practices such as strengthening river banks and stabilizing gully might not lead to improved water quality in Lake Tana