Effect of starter cultures on properties of soft white cheese made from camel (Camelus dromedarius) milk

This experiment was conducted to investigate the effect of starter cultures on the physicochemical properties, texture, and consumer preferences of soft white cheese (SWC) made from camel (Camelus dromedarius) milk. The experiment was laid out in a completely randomized design with 5 treatments [starter cultures; i.e., 1 thermophilic (STI-12), 2 blended (RST-743 and XPL-2), and 2 mesophilic (R-707 and CHN-22) cultures]. Starter cultures STI-12 and RST-743 were inoculated at 37°C, whereas XPL-2, R-707, and CHN-22 were inoculated at 30°C. Camel milk inoculated using STI-12 and RST-743 cultures resulted in faster acidification than XPL-2, R-707, and CHN-22 cultures. Camel milk SWC made using STI-12 and CHN-22 cultures gave lower pH (4.54) and titratable acidity (0.59), respectively, whereas R-707 culture resulted in high cheese yield (13.44 g/100 g). In addition, high fat (20.91 g/100 g), protein (17.49 g/100 g), total solids (43.44 g/100 g), and ash (2.40 g/100 g) contents were recorded for SWC made from camel milk made using RST-743 culture. Instrumental analysis of cheese texture revealed differences in resistance to deformation in which camel milk SWC made using RST-743 culture gave higher firmness (3.20 N) and brittleness (3.12 N). However, no significant difference was observed among camel milk SWC adhesiveness made using different starter cultures. Consumer preference for appearance, aroma, taste, and overall acceptances of SWC were affected by inoculation of starter cultures. Considering curd firmness, cheese yield, compositional quality, and textures using STI-12, RST-743, and R-707, these cultures were found to be better for the manufacture of camel milk SWC.     

Assessing spatio-temporal rainfall variability in a tropical mountain area (Ethiopia) using NOAA’s rainfall estimates

Seasonal and interannual variation in rainfall can cause massive economic loss for farmers and pastoralists, not only because of deficient total rainfall amounts but also because of long dry spells within the rainy season. The semi-arid to sub-humid mountain climate of the North Ethiopian Highlands is especially vulnerable to rainfall anomalies. In this article, spatio-temporal rainfall patterns are analysed on a regional scale in the North Ethiopian Highlands using satellite-derived rainfall estimates (RFEs). To counter the weak correlation in the dry season, only the rainy season rainfall from March till September is used, responsible for approximately 91% of the annual rainfall. Validation analysis demonstrates that the RFEs are well correlated with the meteorological station (MS) rainfall data, i.e. 85% for RFE 1.0 (1996–2000) and 80% for RFE 2.0 (2001–2006). However, discrepancies indicate that RFEs generally underestimate MS rainfall and the scatter around the trendlines indicates that the estimation by RFEs can be in gross error. A local calibration of RFE with rain gauge information is validated as a technique to improve RFEs for a regional mountainous study area. Slope gradient, slope aspect, and elevation have no added value in the calibration of the RFEs. The estimation of monthly rainfall using this calibration model improved on average by 8%. Based upon the calibration model, annual rainfall maps and an average isohyet map for the period 1996–2006 were constructed. The maps show a general northeast–southwest gradient of increasing rainfall in the study area and a sharp east–west gradient in its northern part. Slope gradient, slope aspect, elevation, easting, and northing were evaluated as explanatory factors for the spatial variability of annual rainfall in a stepwise multiple regression with the calibrated average of RFE 1.0 as dependent variable. Easting and northing are the only significant contributing variables (R² = 0.86), of which easting has proved to be the most important factor (R² = 0.72). The scatter around the individual trendlines of easting and northing corresponds to an increase in rainfall variability in the drier regions. Despite the remaining underestimation of rainfall in the southern part of the study area, the improved estimation of spatio-temporal rainfall variability in a mountainous region by RFEs is valuable as input to a wide range of scientific models.     

Genotypic variation for potassium uptake and utilization efficiency in wheat

Pot and field experiments were carried out in order to study the genotypic variation in potassium uptake and utilization by winter wheat (T. aestivum L). Fifty-eight genotypes showed variation in K concentration, accumulation and potassium efficiency ratio (KER) in a field experiment. KER had significant positive correlation with grain weight per spike and harvest index (HI), and significantly negative correlation with stem K concentration at maturity. In a subsequent field experiment, three out of four genotypes, Yunmei 5, 94-18 and 94-6 differed in their KER, and had significantly higher grain yield with K application (K1) than without K application (K0). The 4th genotype Zhemei 1 showed no response to K. The yield increase due to K application was mainly due to the improvement in spike development from tillers. K concentration and accumulation in the plant varied between genotypes, K levels and plant parts. Among various plant parts, stem contained the highest K concentration and had the highest K accumulation at maturity, and changed considerably with the K level, while other plant parts remained relatively unchanged. All four genotypes had smaller KER in K1, as compared to K0, but there existed some difference in KER reduction among genotypes.     

Agronomic and economic performance of reservoir sediment for rehabilitating degraded soils in Northern Ethiopia

Nutrient export through sediment is, often, not given due attention in improving the fertility of soils. A Randomized Complete Block Design (RCBD) (replicated three times) was conducted to assess the effect of sediment, collected from a microdam, on the yield of a local wheat cultivar (Triticum aestivum) grown on a Luvisol and a Vertisol during cropping season of 2003 and 2004 in Tigray, Ethiopia. In the first season, the treatments consisted of applying 34.3 Mg sediment ha⁻¹ (T1), 0.1 Mg urea ha⁻¹ (T2), 4 Mg manure ha⁻¹ (T3) and a control plot (T4). The experiment was repeated in the 2004 cropping season using the same indicator crop but without the use of T1 and T3 inputs to evaluate the residual effect of these treatments on crop productivity. Plant height, plant density, spike length, straw and grain yield were compared among the treatments. After harvest, surface soil (0–25 cm) samples were taken and analyzed for total Nitrogen (Ntot), available Phosphorous (P), Soil Organic Carbon (SOC), Cation Exchange Capacity (CEC), and porosity to examine treatments effect on these soil properties. Higher CEC, exchangeable bases, SOC, Ntot, available P and micronutrients except Cu characterized sediment compared to the two soils used. Application of sediment increased the average grain and straw yield of wheat by 72% and 12%, respectively, in the Luvisol, and by 38% and 23%, respectively, in the Vertisol relative to the control. However, the application of sediment didn’t change the physicochemical properties of the Vertisol, but in the Luvisol CEC and available P were increased significantly. Like manure, sediment provided marginal rate of return above the minimum acceptable value (100%) by farmers, demonstrating the potential of these resources to improve degraded soils and boost farmers’ income.     

Promoting GMP implementation: developing training materials for the international audience.

This paper outlines the development of a CD-ROM training package entitled: The WHO Basic Training Modules on GMP, intended to support the creation of training courses aimed particularly at government compliance officials who inspect pharmaceutical manufacturing facilities. The material was created over a three-year period in collaboration with a team of external experts, WHO regional and local offices, and Drug Regulatory Authorities of participating countries. The nine training workshops and courses that contributed to the development and evaluation processes were attended by approximately 240 participants from 47 countries. To date over 5,800 copies of the CD-ROM have been distributed.     

Desertification? Northern Ethiopia re-photographed after 140 years

A collection of sepia photographs, taken during Great Britain's military expedition to Abyssinia in 1868, are the oldest landscape photographs from northern Ethiopia, and have been used to compare the status of vegetation and land management 140 years ago with that of contemporary times. Thirteen repeat landscape photographs, taken during the dry seasons of 1868 and 2008, were analyzed for various environmental indicators and show a significant improvement of vegetation cover. New eucalypt woodlands, introduced since the 1950s are visible and have provided a valuable alternative for house construction and fuel-wood, but more importantly there has also been locally important natural regeneration of indigenous trees and shrubs. The situation in respect to soil and water conservation measures in farmlands has also improved. According to both historical information and measured climatic data, rainfall conditions around 1868 and in the late 19th century were similar to those of the late 20th/early 21st century. Furthermore, despite a ten-fold increase in population density, land rehabilitation has been accomplished over extensive areas by large-scale implementation of reforestation and terracing activities, especially in the last two decades. In some cases repeat photography shows however that riparian vegetation has been washed away. This is related to river widening in recent degradation periods, particularly in the 1970s-1980s. More recently, riverbeds have become stabilized, and indicate a decreased runoff response. Environmental recovery programmes could not heal all scars, but this study shows that overall there has been a remarkable recovery of vegetation and also improved soil protection over the last 140 years, thereby invalidating hypotheses of the irreversibility of land degradation in semi-arid areas. In a highly degraded environment with high pressure on the land, rural communities were left with no alternative but to improve land husbandry: in northern Ethiopia such interventions have been demonstrably successful.     

Microglia-Derived Olfactomedin-like 3 Promotes Pro-Tumorigenic Microglial Function and Malignant Features of Glioma Cells

Under the influence of transforming growth factor-beta (TGFβ), glioma-associated microglia produce molecules that promote glioma growth and invasion. Olfactomedin-like 3 (Olfml3), a novel, secreted glycoprotein, is known to promote several non-CNS cancers. While it is a direct TGFβ1 target gene in microglia, the role of microglia-derived OLFML3 in glioma progression is unknown. Here, we tested the hypotheses that microglial Olfml3 is integral to the pro-tumorigenic glioma-associated microglia phenotype and promotes glioma cell malignancy. Using an Olfml3 knockout microglial cell line (N9), we demonstrated that Olfml3 is a direct target gene of all TGFβ isoforms in murine microglia. Moreover, loss of Olfml3 attenuated TGFβ-induced restraint on microglial immune function and production of cytokines that are critical in promoting glioma cell malignancy. Importantly, microglia-derived OLFML3 directly contributes to glioma cell malignancy through increased migration and invasion. While exposure to conditioned medium (CM) from isogenic control microglia pre-treated with TGFβ increased mouse glioma cell (GL261) migration and invasion, this effect was abolished with exposure to CM from TGFβ-treated Olfml3^-/- microglia. Taken together, our data suggest that Olfml3 may serve as a gatekeeper for TGFβ-induced microglial gene expression, thereby promoting the pro-tumorigenic microglia phenotype and glioma cell malignancy.     

Analytical study of heat and mass transfer in unsteady MHD radiant flow of Williamson nanofluid over stretching sheet with heat generation and chemical reaction

This paper presents the analytical study of heat and mass transfer in a two-dimensional time-dependent flow of Williamson nanofluid near a permeable stretching sheet by considering the effects of external magnetic field, viscous dissipation, Joule heating, thermal radiation, heat source, and chemical reaction. Suitable transformations are introduced to reformulate the governing equations and the boundary conditions convenient for computation. The resulting sets of nonlinear differential equations are then solved by the homotopy analysis method. The study on the effects of relevant parameters on fluid velocity, temperature, and concentration profiles is analyzed and presented in graphical and tabular forms. Upon comparison of the present study with respect to some other previous studies, a very good agreement is obtained. The study points out that the transfer of heat can substantially be enhanced by decreasing viscoelasticity of the fluid and the transfer of mass can be facilitated by increasing permeability of the stretching sheet.     

Variation in lipid composition of niger seed (Guizotia abyssinica Cass.) Samples collected from different regions in ethiopia

Niger seed samples were collected from different regions in Ethiopia for determination of oil content, and of fatty acid, tocopherol and sterol composition in the seed oil by gas-liquid chromatography and high-performance liquid chromatography methods. There was a large variation in oil content, ranging from 29 to 39%. More than 70% of the fatty acids was linoleic acid (18∶2) in all samples analyzed. The other predominant fatty acids were palmitic (16∶0), stearic (18∶0) and oleic (19∶1) at a range of 6 to 11% each. Total polar lipids recovered after preparative thin-layer chromatography comprised a small fraction of the total lipids. They had higher 16∶0 and lower 18∶2 contents than the triacylglycerols.α-Tocopherol was the predominant tocopherol in all samples, 94–96% of the total amounting to 630–800 μg/g oil. More than 40% of the total sterols wasβ-sitosterol,ca. 2000μg/g oil. The other major sterols were campesterol and stigmasterol, ranging from 11 to 14%. The Δ5- and Δ7-avenasterols were in the range of 4 to 7%. From the samples studied, no conclusion could be drawn regarding the influence of altitude or location on oil content, tocopherol and/or sterol contents. The results of the present study on niger seed oil are discussed in comparison with known data for common oils from Compositae,viz, safflower and sunflower.