SINET: Ethiopian Journal of Science

State of Ethiopia’s vertebrate fauna: Implications for implementation of the post-2020 global biodiversity framework

Sun, 29 Dec 2024 00:00:00 +0000

Biodiversity status indicators, such as number of threatened species, species population sizes and the Red List Index (RLI), are crucial tools to track changes in the state of biodiversity in response to the success or failure of conservation measures. However, such biodiversity status indicators are rarely incorporated in national biodiversity action plans of many countries, including Ethiopia. In this review article, we aimed to assess the potential use of the aforementioned indicators for biodiversity monitoring in Ethiopia. Specifically, we analysed (i) number of threatened vertebrate species of Ethiopia, (ii) trends in species’ population sizes and (iii) overall trend in the Red List Index (RLI) of threatened species. Results showed that Ethiopia harbours 1,715 vertebrate species, including 188 (11%) endemic species. However, many of them are under unfavourable conservation status: 109 species are globally threatened, and 384 species are experiencing Decreasing trends of population sizes. Furthermore, IUCN red list status of 644 species and trends in population sizes of 243 species have been unknown, with many of these species are endemic to the country. The RLI of species survival for Ethiopia showed a constant trend (i.e., RLI = 0.85) over the last 30 years, indicating that the aggregated extinction risk for threatened vertebrate species in the country is unchanged over time. Overall, this study highlights the potential use of these biodiversity status indicators to track changes in the state of biodiversity of the country in response to conservation efforts. We also identified 128 priority species for urgent research and/or conservation actions.

Essential oil and smoke components of Indigofera Arrecta

Sun, 29 Dec 2024 00:00:00 +0000

Indigofera arrecta, commonly known as Buk-Buk (Amharic) in Ethiopia, is an important traditional medicinal plant among Ethiopians which is used for the treatment of different ailments. In this study, major components of the essential oil and the smoke obtained from burned I. arrecta were investigated. The smoke from burnt plant material was trapped in methanol and hexane solvents. Using GC-MS, about seventeen compounds were identified from the essential oil, which accounted for 95.10%. Octylacetate (28.54%) was the major component of the essential oil. On the other hand, the solid (sublimed) material obtained during hydrodistillation showed six compounds with a total percent area of 94.88%. The sublimed material was dominated by 1,2,4,5-tetrachloro-3,6-dimethoxybenzene, which accounted for 88.36%. The smoke of I. arrecta showed nine compounds with a combined area of 100%, of which 2, 4-di-tert-butylphenol (31.3%) and 1,2,4,5-tetrachloro-3,6-dimethoxybenzene (25.10%) compounds were the major components. The crude smoke extracts were also examined for their antioxidant activity by using 2,2-dipheneyl-1-picrylhydrizyl (DPPH). The smoke derived from I. arrecta showed 93.52 ± 0.09 DPPH inhibition activities at the concentration of 100 µg/mL which is closer in activity to the standard ascorbic acid. This shows a strong relationship between use of the plant smoke as medicinal incense and its antioxidant activity.

A microbiological and parasitological study of drinking water from point-of-use taps and wastewater from adjacent open ditches in Addis Ketema and Akaki/Kality sub-cities, Addis Ababa, Ethiopia

Sun, 29 Dec 2024 00:00:00 +0000

Wastewater drained through open ditches poses a threat of contamination to households and drinking water distribution lines. This study assessed the bacterial and parasite load of drinking water and wastewater. A total of 205 drinking water and wastewater samples were aseptically collected from three woredas each of Addis Ketema and Akaki/Kality sub-citiesand analyzed for enteric pathogens, total aerobic mesophilic bacteria, enterobacteria, total coliforms,and protozoan and helminth parasites using standard microbiological and parasitological techniques. Wastewater samples from both sub-cities had mean counts of aerobic mesophilic bacteria, enterobacteria and total coliforms above log 6 cfu/ml (CV, <10%). Counts of enterobacteria and total coliform from drinking water in both sub-cities were beyond permissible levels (>log 2 cfu/ml). Mean counts (log cfu/ml) of aerobic mesophilic bacteria, enterobacteria, and coliforms in drinking water showed significant difference at P=0.013 (CI: -0.82722, 0.27937); P<0.001 (CI: -1.797, -3.358) and P<0.001 (CI: -2.289, -0.759] between the two sub-cities, respectively. From surface wastewater samples, only the total coliform counts showed a significant difference with p=0.008 (-1.149, 0.003), however, there was no significant difference in mean counts of aerobic mesophilic bacteria p=0.764 (-0.022, 0.434) and enterobacteria 0.115 (-0.311, 0.363) between sub-cities. No Salmonella or Shigella were encountered.Various non-lactose fermenting Gram negative bacteria, mainly diminated by Proteus Spp., Pseudomonas aeruginosa, and Alcaligenes faecalis were isolated from wastewater in both sub-cities. Protozoan and helminth parasites in wastewater and drinking water samples were mainly dominated by Giardia lamblia, Taenia spp, and Ascaris lumbricoides. In conclusion, drinking water in the study sub-cities was contaminated with various opportunistic pathogens and disease causing parasites. Thus, households in the study sub-cities should treat drinking water before consumption. Responsible authorities should check the integrity of drinking water distribution lines periodically.

Morphometric variation and muscle growth genes polymorphism between two indigenous sheep populations

Sisay Alemu , Helen Nigussie — Sun, 29 Dec 2024 00:00:00 +0000

Ethiopia owns significant sheep genetic resources, but their potential for meat production remains underutilized. Hence, there is a need to characterize their morphometric traits and muscle growth gene polymorphisms of sheep populations. The study aimed to identify the morphometric variation and genetic polymorphism of the Callipyge (CLPG) and Myostatin (MSTN) genes in two sheep populations. Sheep from the North and West Shewa zones of Oromia National Regional State were purposively selected, and morphometric data (body weight and linear body measurements) were collected from 540 sheep (270 from each zone). Blood samples were collected from 180 sheep (90 from each zone) using vacutainer tubes with EDTA for genotyping at the CLPG and MSTN loci. DNA extraction and quality assessment were carried out using salting out procedure and gel electrophoresis, respectively. Polymerase chain reaction amplification was performed with gene specific primers. The amplified products were digested with restriction enzymes and visualized using gel electrophoresis. Morphometric data were analyzed using SPSS, while Popegen32 software was used for analysis of genotype data. Significant variation (p < 0.05) was observed in body weight and linear body measurements and morphometric indices between the two sheep populations. West Shewa sheep showed higher values in most trait and indices considered. Two alleles (A and G) and three genotypes (AA, AG, GG) were detected at the CLPG locus, and two alleles (M and m) with three genotypes (MM, Mm, mm) were identified at the MSTN locus in both populations. In North Shewa sheep, allele frequencies for A and G were equal (0.5), whereas allele G (0.57) was more frequent than allele A (0.43) in West Shewa. For the MSTN gene, the allele frequency of m (0.55) was higher than M (0.45) in North Shewa, while allele M (0.6) was more frequent than allele m (0.4) in West Shewa. Both genes were polymorphic in both populations, with expected heterozygosity and the number of alleles being comparable. The study revealed morphometric variation and polymorphism at the CLPG and MSTN loci in two sheep populations. Further studies with larger sample sizes and different ecotype of sheep populations are needed to validate the current findings and explore the potential of these genes as genetic markers for meat production.

Endangered vegetation ecosystems are rich in unique woody species and hold significant conservation potential before reaching a critical ecological tipping point

Debissa Lemessa — Sun, 29 Dec 2024 00:00:00 +0000

In most cases, the patterns of species assemblies in vegetation ecosystems are shaped by socio-ecological processes. However, the relationship between unique species and threat statuses of vegetation ecosystems remains unexplored. This study assessed how both overall and unique woody species in adjoining vegetation ecosystems are associated with their threat statuses. For this, woody species assessment was undertaken by laying out a line transect (620 m in length) on the adjoining four vegetation ecosystem types to the interior direction at nine sites. Six sample plots (size: 20 ´ 20 m each) were arranged on transects with a 100 m interval. In total, 18 transects and 108 plots were used for data collection. The list of species and number of stems of mature trees and shrubs, saplings and seedlings were recorded. The dataset was organized into three sub-datasets: mature trees and shrubs, saplings, and seedlings. These ecosystems were sorted into four threat categories based on the IUCN threat categories of vegetation ecosystems. The variations in compositions of the overall and the unique woody species between adjoining vegetation ecosystem types having threat categories were tested using Adonis2 function within vegan package. Similarly, the differences in species richness and number of stems were analyzed using one-way ANOVA. The multivariate analysis of variance indicated that the species compositions of all growth stages significantly vary between the ecosystem threat categories (P<0.003). Similarly, both the overall and unique woody species richness is significantly higher in a critically endangered vegetation ecosystems than the adjoining ecosystems with either least concern, near threatened or vulnerable threat categories (P<0.004). These results suggest that the vegetation ecosystems, which were previously floristically diverse but are currently critically endangered, are comprised of higher unique woody species. Hence, this potential needs to be restored before the tipping point triggered by the continuing socio-ecological disturbances.

Water Quality and Trophic Status of Lake Ziway, Ethiopia, determined with contrasting methods and models

Meseret Anteneh, Seyoum Mengistu, Tadesse Fetahi — Sun, 29 Dec 2024 00:00:00 +0000

The published literature on Lake Ziway report disparate data on its water quality and trophic status. This study aimed to determine the current water quality and trophic status of Lake Ziway using recent approaches and extensive sampling regimes. Water and bacteriological samples were collected from seven sampling sites for five months from April to August 2017. Physico-chemical parameters such as DO, EC, pH, and temperature were measured in situ with a portable multimeter probe. Nutrients were determined following the standard procedures of APHA. Total coliform was determined by spread plate technique and fecal coliform with membrane filter method. Water quality was computed with weighted arithmetic Water Quality Index method. Trophic status was calculated with Carlson index, and other two indices developed for tropical reservoirs (Lamparelli and Cunha et al.). Results indicated significant spatial difference of physicochemical parameters. Nutrients such as NO₃ and TP varied between 0.37-0.18 mgL^-1, and 0.24- 1.32 mgL^-1, respectively. Chl a values ranged from 24.3 to 88.1 µgL^-1 and turbidity ^from 71 – 550 NTU.. WQI value was above 100 and indicated poor WQ status. Based on different TSI models, the trophic status of Lake Ziway was determined as hypereutrophic (TSI > 59) from all seven sites. The present study concludes that Lake Ziway is hypereutrophic and not oligo- to eutrophic status as reported earlier and promotes the use of recent TSI models which consider only TP and Chl a data to determine TS. Urgent integrated water management is recommended for the sustainable use of this important freshwater lake in the rift valley.

Some United Boundary-Domain Integral and Integro-Differential Equations to the Dirichlet BVP for a Compressible Stokes System with Variable Viscosity

Goitom W. Hagos, Tsegaye G. Ayele — Sun, 29 Dec 2024 00:00:00 +0000

The Dirichlet boundary value problem (BVP) for a compressible Stokes
system of partial differential equations (PDEs) with variable viscosity is considered in a
bounded three dimensional domain. Using an appropriate parametrix (Levi function),
the problem is reduced to the united boundary-domain integro-differential equation
(BDIDE) or to a domain integral equation supplemented by the original boundary
condition, thus constituting a boundary-domain integro-differential problem (BDIDP).
Solvability, solution uniqueness and equivalence of the BDIDE/BDIDP to the original
BVP as well as invertibility of the associated operators are analysed in appropriate
Sobolev (Bessel potential) spaces.

PERFECT ROLE OF ATOM IN WEAK IDEMPOTENT RINGS

Tamiru Abera, Yibeltal Yitayew, Kolluru Venkateswarlu — Sun, 29 Dec 2024 00:00:00 +0000

In a commutative weak idempotent ring R with unity, we prove that bR = {0, b}
or {0, b, n, b + n} for idempotent and nilpotent atoms b and n of R respectively provided that any
two nilpotent atoms have an upper bound in R. Further, we prove that the subgroup generated by
{ni}i∈I in R is a lattice, where {ni}i∈I is the collection of nilpotent atoms of R corresponding to the
idempotent atoms {bi}i∈I of R. We also prove that R is atomic if and only if RB is atomic provided
that the set of all nilpotent elements of R is nil-free and any two nilpotent atoms have an upper
bound in R. Finally, we state and prove the direct product decomposition theorem of R.