Regulation of protein and carbohydrate intake in caged honeybees Apis mellifera scutellata : assessment based on consumption and various performance measures

When provided with the opportunity to select their diet, most insect herbivores regulate their nutrient intake. However, in a nutritionally heterogeneous environment and with changing demands for growth, development and reproduction, obtaining the required amount and balance of nutrients is a challenge. This is especially true for social insects where the workers bring food into the colony to be shared by nestmates. The ability of insects to self-select their diet is an important trait related to fitness. In this study we investigated whether and how caged worker honeybees meet their nutritional requirements in response to the nutritional composition of the food they find. Using the ‘geometric framework’ we looked at the behavioural and physiological mechanisms used by caged worker honeybees in balancing their diet when provided with different pairs of complementary imbalanced foods. First, we investigated whether caged worker honeybees maintain their intake target by providing them with pairs of complementary imbalanced foods with varying protein to carbohydrate (P:C) ratios. Diets were formulated using different protein sources: casein, royal jelly and Feed-Bee®. Honeybees self-selected or balanced their diet by switching between the complementary foods in accordance with the composition of the food and the type of protein that they encountered. Honeybees selected average P:C ratios of 1:12, 1:14 and 1:11 on casein, royal jelly and Feed-Bee® diets respectively. The level of self-selection was confirmed using two performance measures: survival and ovarian activation. Both survival and ovarian activation differed depending on the type of protein source used. Second, we investigated if honeybees regulated their growth target, which is the amount of nutrients incorporated into growth and storage tissue, by measuring physiological parameters in honeybees confined on imbalanced complementary food combinations having different P:C ratios. Feed-Bee® was used as a protein source. The physiological parameters measured were head fresh mass, hypopharyngeal gland (HPG) development, and protein concentration in the haemolymph. The bees fed on different diet combinations with different P:C ratios maintained each of the performance measures to the same level, which supports the ability of worker honeybees to self-select their diet. The measured physiological parameters were compared with other studies to asses the appropriateness Feed-Bee® diet as a protein source for the bees. In the absence of brood the intake target is directly related to the physiological requirements of the worker bees. The behavior of these individual adult bees gives an insight in to the complex system; similar responses may be seen in nurse bees in the colony condition to obtain protein, carbohydrate and other nutrient requirements from stored pollen and nectar in the hive, either for their own nutritional requirements or for other colony members, especially larvae.Dissertation (MScAgric)--University of Pretoria, 2010.Zoology and Entomologyunrestricte

Prevalence, risk factors and antimicrobial susceptibility profile of Salmonella isolated from dogs of Ambo, Bako and Gojo towns of West Shoa, Ethiopia

Salmonella is the most known zoonotic bacterial agent, which produces salmonellosis in animals as wells as in humans. The objectives of this study were to estimate the prevalence, to determine antimicrobial susceptibility and to assess risk factors associated with Salmonella shedding in dogs in selected towns of West Shoa Zone, Oromia, Ethiopia. Using a cross-sectional design, a total of 438 rectal swab samples were collected from randomly selected dogs for isolation and identification of Salmonella using standard procedures. A questionnaire survey was also administered. The results showed that 48 (11.0%, 95%, [CI]: 8.2% - 14.3 %) dogs were positive for Salmonella. The occurrenceof Salmonella was 10.9% (26/238), 11.6% (15/129) and 9.9% (7/71) in Ambo, Bako and Gojo towns respectively. Salmonella shedding was significantly higher in older dogs (15.0%) than younger ones (6.1 %) (P<0.05). The occurrence of Salmonella was not significantly associated with study towns, sex, breed of dogs,educational level of owners, presence of other domestic animals and housing system (P>0.05). Multivariable logistic regression analysis showed that the odds of isolation of Salmonella was significantly higher in old than young dogs (OR): 2.6, 95% CI: 1.3-5.6, P=0.007) and in dogs eating mixed type of feeds (raw animal products, household leftover) than cooked feed (OR = 9.0, 95% CI: 1.2 – 68.1, P=0.033). There was also a significant difference between kebeles of the study areas in that Salmonella isolation was nearly nine times higher in Bako Kebele 02 (P=0.005) as compared to Ambo kebele 03. Salmonella isolates have developed the highest level of resistance for ampicillin (100%), tetracycline  (93.3%) and streptomycin (80.0 %), however, all isolates were susceptible to Norfloxacin. The occurrence of Salmonella, most of which resistant to commonly used antimicrobials, in rectal swab samples show the potential threat dogs may pose to public health in the study area.Keywords: Antimicrobial Resistance; Dog; Ethiopia; Prevalence; Risk factor; Salmonell

Prevalence, risk factors and antibiogram of Escherichia coli isolated from dogs in Ambo, Gojo and Bako towns of Oromia region, Ethiopia

Dogs are a potential reservoir for Escherichia coli and other zoonotic bacterial pathogens posing the risk of infection to humans and other animals. A crosssectional study was used to collect 438 rectal swab samples from apparently healthy dogs of Ambo, Gojo, and Bako towns of West Shewa Zone with the objectives of investigating the prevalence, risk factors and antibiogram of E. coli. A questionnaire survey was administered at the household level to collect data on potential risk factors to acquire E. coli infection. Prevalence was determined by using standard bacteriological culture techniques. Further  confirmation and antimicrobial susceptibility testing of E. coli using the minimum inhibitory concentration (MIC) method were  conducted using Automated Phoenix Machine. The overall prevalence of E. coli was found to be 24.2% (95% confidence interval [CI]:20.26-28.49%). The isolation rate of E. coli was the highest in Bako 31.01%, followed by Gojo 30.99% and Ambo 18.49% towns.  Univariable and multivariable logistic regression analyses revealed that there was a significant association between E. coli prevalence and towns and Kebeles (P<0.05). However, age, sex, the presence of other domestic animals in the household, types of the housing system, educational level of the dogs’ owners, and type of feed provided to the dogs did not significantly correlate with the isolation of E. coli (P > 0.05). E. coli isolates were pan-susceptible to amikacin, ertapenem, imipenem, piperacillin-tazobactam, netilmicin, ampicillin, piperacillin, cefoxitin, ciprofloxacin, levofloxacin, and meropenem. A low level of resistance was found to aztreonam, ceftriaxone, (each 13.95%), cefazolin (22.73%), gentamicin (11.90%), and trimethoprim-sulphamethoxazole (6.97%). E. coli isolates showed multidrug resistance to aztreonam, cefazolin, ceftriaxone, gentamicin, and trimethoprim-sulphamethoxazole (14.0%). This demonstrated E. coli prevalence and moderately low antimicrobial resistance  suggests the possible risk of infection of humans. Therefore, raising public awareness about zoonotic canine disease prevention measures and good hygienic practices are essential.. Keywords: Antibiogram, Dog, Escherichia coli, Ethiopia, Prevalence, Risk facto

Review of policies and frameworks on climate change, agriculture, food and nutrition security in Ethiopia

Agriculture is the mainstay of Ethiopia’s economy, contributing over 50% of the gross domestic product (GDP), accounting for more than 85% of the labor force and over 90% of the foreign exchange earnings (Alemu et al. 2010). Consequently, the sector receives considerable attention from the government, investing 15% of its total budget over the decade and meeting the commitments by Africa’s heads of states to the African Union Maputo 2003 Declaration on Agriculture and Food Security (CAADP 2003). On average, crop production makes up 60% of the sector’s outputs, livestock accounts for 27%, with other sub-sectors contributing 13% of the total value of agricultural production. The sector is dominated by small-scale farmers, practicing rain-fed mixed farming using traditional technologies, characterized with low levels of input use and low productivity

Whole-Genome Resequencing Reveals Selection Signatures of Abigar Cattle for Local Adaptation

Over time, indigenous cattle breeds have developed disease resistance, heat tolerance, and adaptability to harsh environments. Deciphering the genetic mechanisms underlying adaptive traits is crucial for their improvement and sustainable utilization. For the first time, we performed whole-genome sequencing to unveil the genomic diversity, population structure, and selection signatures of Abigar cattle living in a tropical environment. The population structure analysis revealed that Abigar cattle exhibit high nucleotide diversity and heterozygosity, with low runs of homozygosity and linkage disequilibrium, suggesting a genetic landscape less constrained by inbreeding and enriched by diversity. Using nucleotide diversity (Pi) and population differentiation (FST) selection scan methods, we identified 83 shared genes that are likely associated with tropical adaption. The functional annotation analysis revealed that some of these genes are potentially linked to heat tolerance (HOXC13, DNAJC18, and RXFP2), immune response (IRAK3, MZB1, and STING1), and oxidative stress response (SLC23A1). Given the wider spreading impacts of climate change on cattle production, understanding the genetic mechanisms of adaptation of local breeds becomes crucial to better respond to climate and environmental changes. In this context, our finding establishes a foundation for further research into the mechanisms underpinning cattle adaptation to tropical environments.</p

Variations in soil properties and native woody plant species abundance under Prosopis juliflora invasion in Afar grazing lands, Ethiopia

This research article published by Springer Nature, 2020Introduction Pastoralism and agro-pastoralism are the major modes of life in arid and semi-arid rangelands. However, rangeland quality and quantity are rapidly deteriorating due to a number of natural and human-induced factors, one of which is bush encroachment. Little is known on how bush encroachment affects the ecosystem functions and services expressed in terms of the native vegetation composition and structure, status of the soil seed bank, soil chemical and physical properties, and the abundance of mycorrhiza spores. Methods We assessed woody species in 64 plots distributed across four levels of Prosopis juliflora invasion (high, medium, low, and none) at two sites, Amibara and Gewane, in the Afar Region, Ethiopia. We collected composite soil samples to investigate the soil seed bank, mycorrhizal associations, and spore abundance. Results Plant biodiversity was generally low, with eight and four woody species in Gewane and Amibara, respectively. Prosopis juliflora was dominant in highly, moderately, and lowly invaded areas while Acacia senegal dominated the non-invaded areas. The average number of P. juliflora individuals ranged from 3/ha at non-invaded areas in Gewane to 4200/ha at highly invaded areas in Amibara while the total individual number of native woody species ranged from 0 to 88/ha at highly and lowly invaded areas, respectively. The population structure of trees/shrubs in all invasion areas showed an inverted J-shaped distribution, characterized by a high abundance of small individuals. Prosopis juliflora invasion was associated with high soil OC, Na, Ca, P, bulk density, and moisture content. Herbaceous seed numbers and species richness were highest in the moderately and highly invaded areas. All sampled tree species were associated with mycorrhiza but the percentage of root length colonization by different arbuscular mycorrhizal fungus structures varied significantly (p < 0.05) across invasion categories and sites. Conclusions Our results revealed that although P. juliflora invasion negatively impacted the availability of native woody livestock forage species, it had a positive effect on most soil physical and chemical properties. Such variable effects call out for sustainable management practices when invaded areas are restored

CANCER NANOTHERANOSTICS: A NEW PARADIGM OF SIMULTANEOUS DIAGNOSIS AND THERAPY

Despite  improvements  in  our  understanding  of cancer  and  the  emerging  concept  of personalized medicine for the treatment of this disease, it is still one of the leading causes of death worldwide. Although, in recent years, significant advances have been achieved in cancer therapy, many tumors are still challenging to treat and novel strategies are required to effectively combat this deadly disease. Nanotheranostics is a burgeoning field which makes use of nanotechnology for diagnosis and therapy of cancer. The recent advancement in the area of nanotechnology has enabled a new generation of different types of nanomaterials composed of either inorganic or polymer based nanoparticles to be useful for nanotheranostics applications such as to diagnose and treat diseases and monitoring the therapeutic response in vivo at molecular level; to enhance the control, evaluation and optimization of drug delivery and release; to target the drug by conjugating theranostic nanoplatformes with biological ligands. This review, therefore, summarizes the various nanocarriers developed so far for the simultaneous imaging and therapy, strategies for their targeted delivery, their potential applications and the challenges in their development and application for cancer therapy.   Key words: Cancer; Cancer therapy; Nanoparticles; Nanotheranostics

Establishing a multicenter longitudinal clinical cohort Study in Ethiopia: Advanced Clinical Monitoring of Antiretroviral Treatment Project

Background: The purpose of this paper is to describe the establishment of the  Advanced Clinical Monitoring of ART Project in Ethiopia for monitoring and  evaluation of the longitudinal effectiveness of the ART program and to show the opportunities it presents. This cohort was established in response to the 2005 call by WHO for establishing additional mechanisms for stronger monitoring of ART and the need for creating the platform to generate evidence to guide the care given for the ever increasing number of patients on ART in Ethiopia.Method: A participatory and multi-stage process which started from a consensus building workshop and steered by a mother protocol as well as guiding documents which dictated the degree of engagement and expectations was followed. The primary and secondary aims of the study were agreed upon. A multi-site longitudinal observational clinical cohort was established by a consortium of stakeholders including seven Ethiopian medical schools and their affiliated referral hospitals, John Hopkins University, Ethiopian Public Health Institute, Ministry of Science and Technology, US Centers for Disease Prevention and Control - CDC-Ethiopia, and the Federal Ministry of Health. Adult and adolescent cohorts covering the age range of 14+ years) and pediatric cohorts covering those below age 14 years were the two main cohorts. During the initial recruitment of these cohorts information was extracted from existing documents for a total of 2,100 adult participants. In parallel, a prospective cohort of 1,400 adult and adolescent patients were enrolled for ART initiation and follow-up. Using similar recruitment procedures, a total of 120 children were enrolled in each of retrospective and prospective cohorts. Replacement of participants were made in subsequent years based on lost follow up and death rates to maintain adequacy of the sample to be followed-up.Achievements: Between January 2005 and August 2013 a total of 4,339 patients were followed for a median of 41.6 months and data on demographic characteristics, baseline and ongoing clinical features, hospitalization history, medication and laboratory information were collected. 39,762 aliquots and 25,515 specimens of plasma and dry-blood-spots respectively were obtained and stored longitudinally from October 2009 to August 2013. The project created a research platform for researchers, policy and decision makers. Moreover, it encouraged local and international investigators to identify and answer clinically and programmatically relevant research questions using the available data and specimens. Calls for concept notes paired with multiple trainings to stimulate investigators to conduct analyses further boosted the potential for doing research.Conclusions: A comprehensive and resourceful mechanism for scientific inquiry was established to support the national HIV/ART program. With meaningful involvement and defined roles, establishment of a study, which involved multiple institutions and investigators, was possible. Since ACM is the largest multi-site clinical cohort of patients on antiretroviral treatment in Ethiopia---which can be used for research and for improving clinical management---considering options to sustain the project is crucial. Key Words: Ethiopia, HIV clinical cohort, Antiretroviral therapy, Establishing Longitudinal Cohort Study, ART Monitoring and Evaluatio

Health system modelling research : towards a whole-health-system perspective for identifying good value for money investments in health system strengthening

Global health research has typically focused on single diseases, and most economic evaluation research to date has analysed technical health interventions to identify 'best buys'. New approaches in the conduct of economic evaluations are needed to help policymakers in choosing what may be good value (ie, greater health, distribution of health, or financial risk protection) for money (ie, per budget expenditure) investments for health system strengthening (HSS) that tend to be programmatic. We posit that these economic evaluations of HSS interventions will require developing new analytic models of health systems which recognise the dynamic connections between the different components of the health system, characterise the type and interlinks of the system's delivery platforms; and acknowledge the multiple constraints both within and outside the health sector which limit the system's capacity to efficiently attain its objectives. We describe priority health system modelling research areas to conduct economic evaluation of HSS interventions and ultimately identify good value for money investments in HSS