Effects of cryostabilizers, low temperature, and freezing on the kinetics of the pectin methylesterase-catalyzed de-esterification of pectin

The kinetics of the pectin methylesterase (PME)-catalyzed de-esterification of pectin was studied at 25 degrees C in the presence of sucrose, fructose, maltodextrin (DE = 16.5-19.5), and carboxymethylcellulose at different concentrations and in the presence of maltodextrin and sucrose at different concentrations in a temperature range between +25 and -4 degrees C in subcooled and frozen states. The objective was to determine whether the reaction is diffusion-controlled, to gain insight about the factors determining the diffusion of the reactants, and to determine the effect of the carbohydrates, low temperature, and freezing on the structural conformation of the enzyme. The results indicate that the PME-catalyzed de-esterification of pectin is diffusion-controlled. Nevertheless, the diffusion is not controlled by the macroviscosity of the reaction medium, but rather by the microviscosity experienced by the diffusants. Low temperature in the temperature range studied does not affect the structural conformation of the enzyme, while freezing seems to have some effect.     

Small ruminant brucellosis and community perception in Jijiga District,Somali Regional State,Eastern Ethiopia

A cross-sectional study of brucellosis in small ruminants was carried out from October 2008 to March 2009 in Jijiga District, Somali Regional State of Ethiopia. Seven hundred thirty sera samples (421 of sheep and 309 of goats) were randomly collected from purposively selected villages of the study area. Structured questionnaire format was developed, pre-tested and administered to assess the perception of the community pertaining to brucellosis in sheep and goats. Sera samples were screened by Rose Bengal Plate Test (RBPT), and all samples tested positive by the RBPT were subjected to Complement Fixation Test (CFT) for confirmation. Of 12 serum samples that were positive by RBPT, 11 were positive by CFT. Statistically significant differences were not observed between the species as well as the sex groups (P > 0.05); however, the variation between the age groups was statistically significant (P < 0.05). Analysis of the questionnaire survey suggests that improper handling of aborted materials, consumption of raw milk, and lack of awareness about the disease, among others, might greatly contribute to further spread of brucellosis in their livestock and exposes the community to a public health hazard. In general, the sero-prevalence in the study area was not so high; nevertheless, appropriate brucellosis control and prevention methods should be implemented to circumvent future potential for economic losses and the public health hazard of the disease.     

Vegetation structural characteristics and topographic factors in the remnant moist Afromontane forest of Wondo Genet, south central Ethiopia

For forest ecosystem management to be effective, knowledge of the horizontal and vertical structural diversity of a forest is essential. The moist Afromontane highlands of Wondo Genet in south-central Ethiopia present an opportunity to restore and rehabilitate and enhance the ecosystem services to be obtained from this forest sustainably. We focused on the forest structural characteristics to better understand the current forest conditions to assist in the sustainable management of this resource. A total of 75 (20 m × 20 m) quadrats were sampled and diameter at breast height (DBH) ≥ 2 cm and stem height ≥ 2 m were measured. Species identity and abundance, elevation, slope, and aspect were recorded for each plot. Structural characteristics were computed for each plot. Relationship of topographic factors with vegetation characteristics was conducted using R-Software. A total of 72 woody species was recorded. Whereas, the overall diameter distribution shows an inverted J-shaped curve, the basal area followed a bell-shaped pattern. Five types of population structures are revealed. The mean tree density and basal area was 397.3 stems·ha^?1 and 31.4 m²·ha^?1, respectively. Only 2.8% of the tree species have densities of >25 stems·ha^?1 and the percentage distribution of trees show 56.2% in the DBH class 2–10 cm, indicating that the forest is dominated by medium-sized trees. Celtis africana (8.81 m²·ha^?1) and Pouteria adolfi-friedericii (5.13 m²·ha^?1) make the highest contribution to the basal area and species importance value index. The families/species with the highest importance value index are Ulmaceae, Fabacea and Sapotaceae. Species abundance (r ² =0.32, p <0.001) and species richness (r ² =0.50, p <0.001) are positively related with tree density. Tree density is negatively related with elevation (r ² =?0.36, p <0.001), slope (r ² =?0.15, p <0.001) and aspect (r ² =?0.07, p <0.05). While basal area is negatively related with elevation (r ² =?0.14, p <0.001), it has a positive relationship with tree density (r ² =0.28, p <0.001 and species richness (r ² =0.098). Species with poor population structure should be assisted by restoration tasks and further anthropogenic disturbance such as illegal logging and fuel wood extraction should be restricted.     

Contribution of participatory forest management towards conservation and rehabilitation of dry Afromontane forests and its implications for carbon management in the tropical Southeastern Highlands of Ethiopia

Participatory forest management (PFM) has been applied as an approach to create a framework for collaborative forest management between local communities and government forestry agencies. This study was designed to assess the contribution of PFM approach in improving forest status in the Southeastern Highlands of Ethiopia. Landsat satellite imageries of four years were used to evaluate the trends and rate of deforestation before and after PFM interventions. Socio-economic data were collected from sample household surveys, key participants, focus group discussions, and field observations. The results showed that there was high rate of deforestation before PFM intervention as forestland has decreased by 19% (2531 ha) between 1990 and 2000. However, after the PFM intervention (2000–2016), the forest cover has increased by 247 ha (2.2%). During this period, net 1016 ha of shrub-lands were converted into forestland owing to significant forest regeneration. In addition, most sampled households (94% and 96% from lower and upper altitudes, respectively) perceived that PFM had significantly contributed to improve forest regeneration in their locality. This study revealed that PFM can serve as a stepping stone for carbon financing mechanisms to reduce greenhouses emission and enhance carbon sinks via forest resources.     

Investigating maternal effects on production traits in Duroc pigs using animal and sire models

Variance components for production traits were estimated using different models to evaluate maternal effects. Data analysed were records from the South African pig performance testing scheme on 22 224 pigs from 18 herds, tested between 1990 and 2008. The traits analysed were backfat thickness (BFAT), test period weight gain (TPG), lifetime weight gain (LTG), test period feed conversion ratio (FCR) and age at slaughter (AGES). Data analyses were performed by REML procedures in ASREML, where random effects were successively fitted into animal and sire models to produce different models. The first animal model had one random effect, the direct genetic effects, while the additional random effects were maternal genetic and maternal permanent environmental effects. In the sire model, the random effects fitted were sire and maternal grand sire effects. The best model considered the covariance between direct and maternal genetic effects or between sire and maternal grand sire effects. Fitting maternal genetic effects into the animal model reduced total additive variance, while the total additive variance increased when maternal grand sire effects were fitted into the sire model. The correlations between direct and maternal genetic effects were all negative, indicating antagonism between these effects, hence the need to consider both effects in selection programmes. Direct genetic correlations were higher than other correlations, except for maternal genetic correlations of FCR with TPG, LTG and AGES. There has been direct genetic improvement and almost constant maternal ability in production traits as shown by trends for estimated (EBVs) and maternal breeding values (MBVs), while phenotypic trends were similar to those for EBVs. These results suggest that maternal genetic effects should be included in selection programmes for these production traits. Therefore, the animal–maternal model may be the most appropriate model to use when estimating genetic parameters for production traits in this population.     

Diversity,regeneration status and population structure of gum- and resin-bearing woody species in south Omo zone,southern Ethiopia

South Omo Administrative Zone in Ethiopia is home to 18 indigenous ethnic groups whose livelihood is vulnerable due to recurrent drought and degradation. Despite the preliminary observation showing the rich dry-forest resource base that, if sustainably managed could enhance livelihoods and biodiversity conservation, there is lack of empirical data on its current status. We conducted a study aiming at quantifying the population status of gum- and resin-bearing species in two randomly selected districts, Hamer and Bena-Tsemay. Seventy-five quadrats(35 at Hamer and 40 at Bena-Tsemay) each measuring 400 m2 were established along line transects to assess species diversity and equitability, density, frequency, dominance, importance value and population structure. We recorded a total of 27 woody species of 12 families and 14 genera. Fifteen species(9 at Hamer and 14 at Bena-Tsemay) of the genera Acacia, Boswellia, Commiphora and Sterculia, were identified as either major sources of commercial gums and resins or their adulterants. Gum- and resin-bearing species comprised 56% and 57% of species richness, 48% and 50% of total density per ha, 95% and 98% of basal area, and 64% and 56% of importance values at Hamer and Bena-Tsemay, respectively. Diversity of the entire woody species assemblage and of the gum- and resin-bearing species was slightly higher at Bena-Tsemay(H= 2.61, 1.4) than at Hamer(H′= 2.48, 1.28), respectively. The diversity and abundance of the resource base suggest potential for development of value-added commercialization of gum and resins to enhance livelihoods and encourage sustainable management of the forest at these study areas. We recorded, however, declining natural regeneration of most gum- and resin-bearing species, and this calls for integrated and participatory species management and landscape rehabilitation.     

Major metacestodes in cattle slaughtered at Wolaita Soddo Municipal abattoir,Southern Ethiopia: Prevalence,cyst viability,organ distribution and socioeconomic implications

A cross sectional study to determine the prevalence and socioeconomic importance of major metacestodes of cattle was conducted from November 2007 to April 2008 at Wolaita Soddo abattoir. Accordingly, of 415 randomly selected slaughtered cattle, 11.3% and 15.4% were infected with Cysticercus bovis and hydatid cysts, respectively. The anatomical distributions of these parasites include various organs. The major risk factors for cysticercosis prevalence were origin of the animals (P < 0.001, OR = 7.3) and breeds (P = 0.004, OR = 4.3), and hydatid cysts prevalence was significantly varied with different origins (P = 0.021, OR = 2.8). The viability of C. bovis was higher (28.3%) than that of hydatid cyst (1.7%). Of 79 interviewed respondents, 50.63% had acquired taeniasis and analysis of the risk factors showed association of religions (P = 0.003, OR = 24.4), occupation (P < 0.001, OR = 6.9), educational background (P = 0.035, OR = 2.7) and age (P < 0.001, OR = 3.9) of the respondents with taeniasis prevalence. Furthermore, the inventory of taeniasis drugs dose and treatment cost were estimated to be 335,772 adult doses and 93,310 USD. In conclusion, the findings of the present study imply the zoonotic and socioeconomic importance of the diseases, which need intervention.     

Reference intervals for biochemical and haematological parameters in mature domestic donkeys (Equus asinus) in the UK

Reference intervals (RIs) for haematology and serum biochemistry for donkeys in a temperate climate have been previously published using blood sample results from the resident population of a large donkey shelter in the UK. Periodic review of reference intervals is recommended to ensure their applicability to the patient population and changes in laboratory methods and technologies. The current study aimed to revise the previously published haematology and serum biochemistry values for the adult domestic donkey (Equus asinus) in the UK in the light of a change in analytical equipment at the Donkey Sanctuary laboratory, but also to refine the demography of the sample population with respect to age, physiology and clinical history. Clinical pathology results from 138 clinically healthy mature (4–24 years inclusive) female and castrated male donkeys selected from the resident population of the Donkey Sanctuary, were analysed retrospectively. The animals were blood sampled during the period February 2008 to June 2011 as part of a routine health screen prior to rehoming. Results for a total of 38 biochemical and haematological parameters were analysed including 3 previously unreferenced parameters in addition to those assessed in the previous study. The new reference intervals and median values show very poor transferability with recently derived reference intervals for non‐Thoroughbred horses and only limited transferability with reference intervals previously published for donkeys in the UK. Of particular note is a marked reduction in the upper reference limit for triglycerides of 2.8 mmol/l (from 4.3 mmol/l) since this parameter is used to decide when donkeys are at risk of developing hyperlipaemia. This study demonstrates the value of intermittent review of reference intervals and refinement of study populations. Notwithstanding the caution with which reference interval data from different laboratories should be compared, the lack of transferability of results between donkeys and horses highlights the importance of use of species‐appropriate reference intervals for clinical decision‐making.