Development and Application of a Synthetic Near Infrared Fluorescent Probe for Imaging Modulatory Neurotransmitters

Dopamine neurotransmission plays critical roles in brain function in both health anddisease and aberrations in dopamine neurotransmission are implicated in severalpsychiatric and neurological disorders, including schizophrenia, depression, anxiety, andParkinson’s disease. Until recently, measuring the dynamics of dopamine and otherneurotransmitters of this class could not be achieved at spatiotemporal resolutionsnecessary to study how dopamine regulates the plasticity and function of neurons and neuralcircuits, and how dysfunctions in this regulation lead to disease. Probes that satisfy criticalattributes in spatiotemporal resolution and chemical selectivity are needed to facilitateinvestigations of dopamine neurochemistry.To address this need, this dissertation describes the synthesis and implementation ofan ultrasensitive near-infrared “turn-on” nanosensor (nIRCat) for the catecholamineneuromodulators dopamine and norepinephrine. To guide probe development, we presentresults from a computational model that offers insight into the spatiotemporal dynamics ofdopamine in the striatum, a subcortical structure that is enriched in dopamine. With thismodel, we elucidated the kinetic requirements for a prototypical optical indicator as well asoptimal imaging frame rates needed for measuring dopamine neurochemical dynamics.Stochastic modeling of dopamine dynamics, driven by kinetic phenomena of vesicularrelease, diffusion and clearance, provide a platform to evaluate dopaminergic volumetransmission arising from a single terminal or ensemble terminal activity. With this work,we illustrate that only probes with kinetic parameters in a particular range are feasible fordopamine imaging at spatiotemporal scales likely to be encountered in brain tissue.In two subsequent chapters, we describe the development and in vitrocharacterization of nIRCats, synthesized from functionalized single wall carbon nanotubes(SWCNT) that fluoresce in the near infrared range of the spectrum. We show that nIRCatsexhibit maximal relative change in fluorescence intensity (ΔF/F0) of up to 35-fold inresponse to catecholamines and have optimal dynamic range that span physiologicalconcentrations of their target brain analytes. Through a combination of experimental andmolecular dynamics approaches, we elucidate the photophysical principles and intermolecularinteractions that govern the molecular recognition and fluorescence modulation of nIRCats by dopamine.Finally, we demonstrate that nIRCat can be used to measure electrically andoptogenetically evoked release of dopamine in striatal brain slices, revealing hotspots ofactivity with a median size of 2 μm, and exhibiting a log-normal size distribution that extendsup to 10 μm. Moreover, nIRCats are shown to be compatible with dopamine pharmacologyand permit studies of how receptor-targeting drugs modulate evoked dopamine release. Ourresults suggest nIRCats may uniquely support similar explorations of processes that regulatedopamine neuromodulation at the level of individual synapses, and exploration of the effectsof receptor agonists and antagonists that are commonly used as psychiatric drugs andpsychoactive molecules that modulate the release and clearance profiles of dopamine. Weconclude that nIRCats and other nanosensors of this class can serve as versatile syntheticoptical tools to monitor interneuronal chemical signaling in the brain extracellular space atspatial and temporal scales pertinent to the encoded information

Feed Resources of Honeybees in Kewet District of Amhara, Ethiopia

A study was conducted in Kewet district of North Shewa zone Amhara Regional State to assess the feed resources of honeybees. Cross-sectional types of studies were used to collect data. Using a purposive sampling technique, 60 beekeepers were included in the survey. Data were analyzed using Statistical Package for Social Sciences software. Plants that are generally considered to be toxic to bees and humans or suspected in the study areas by the respondents are: Gumero, Yeferenj Digit (Cassia siamea), Bisan (Croton macrostachyus), Iret (Aloe brahana), Foch (Zizyphusmucronata), Endod (Phytolaccadodecandra) and Susbania species. Survey conducted in the district showed that the cultivated and natural honey flora potential of the area makes it very favorable for beekeeping. The study district besides cereals, pulses and shrubs/trees/herbs it has known for its horticulture production. Based on the source status and abundance, 60 plant species were identified by the respondents as important bee flora in the study area. The respondents indicated that even though there are different types of bee plants in honey flora seasons, there is a shortage of bee food during the dry seasons. They also indicated that bee forages become declining as compared with the past period due to forest degradation, population growth and expansion of cultivated lands in the area. Key words: feed resources, beekeepers, colony, poisonous, Kewet

Early Growth and Reproductive Performances of Horro Cattle and thier F1 Jersey Crosses in and around Horro-Guduru Livestock Production and Research Center, Ethiopia

A cross-sectional survey, an assessment of recorded data and  measurements of different traits were conducted to determine the reproductive and early growth performances of Horro cattle and their F1 Jersey crosses of the study area. The mean(SD) total farmland, cropland and grazing land holdings of individual smallholder householders were 3.6±3.16, 2.86±2.51 and 0.81±0.89 respectively, while the mean(SD) livestock species holding were 17±11.66, 2.9±3.98,2.9 ±4.83, 1.8±1.66 and 9.3±8.97 for cattle, sheep, goats, equine and poultry respectively. Anestrous, repeat breeder, endo-metritis and dystocia were the main reproductive health problems which were found to occurs with the  proportion of 21.1%, 19.7%, 5.6% and 1.4%, while the remaining 52% attribute to non pregnancy in cows due to voluntary waiting period, postpartum period and lack of AI service. The overall mean age at first service across both production sites(on station and on farm) was 48.85 months for local Horro and 33.25 months for Horro-Jersey F1 Crosses, where as the mean (SD) NSPC for Horro and Horro-Jersey crossbred heifers was found 2.1±1.09 and 1.7±0.94 respectively. Breed of animals had high  significance effect at (P < 0.001) on AFS and AFC. The mean birth weight of Horro and Horro-Jersey crossbred calves was 17.5±2.25 and 18.2±2.03 kg respectively. Calf birth weight was significantly (P<0.001) influenced by breed and sex, season and year of birth of a calf. The mean (SD) body weight measure of Horro calves at six, twelve, eighteen and twenty four months age is found to be 69.8±31.19, 117.7±22.65, 129.4±24.82 and 150±23.56 Kg respectively. While, their respective counterpart Horro-Jersey F1 crossbred calves were found to weigh 64.42±10.18, 136.6±27.97 and 145.1±22.27 kg mean(SD) body weight at six, twelve and eighteen  months of ages respectively

A survey of the farming systems of Vertisol areas of the Ethiopian highlands

In 1986, ILCA carried out informal surveys at Dogollo and Inewari in order to understand the farming systems. Such surveys were also conducted by the Institute of Agricultural Research (IAR) at Ginchi in 1986 and by the Alemaya University of Agriculture at Ada/Debre Zeit in 1988/89. This was followed by one-time detailed formal farm surveys at Dogollo, Inewari and Ginchi in 1988/89. This chapter mostly presents the results of these formal surveys. The objectives of the surveys were to understand the existing farming systems in order to develop appropriate Vertisol technologies, to identify production constraints and opportunities for technological interventions, to identify recommendation domain, and to compile baseline data in order to assist in ex-post Vertisol - technology evaluation. Natural resources, farm resources, crop and livestock interaction, feed production and livestock feeding, constraints to production, livestock production constraints and researchable areas are examined

Dairy Productive Potential, Challenges and Production opportunities of Horro and their F1 Jersey Crossbred Cows: A Case of Guduru Livestock Production and Research Center and Its Surroundings, West Oromia, Ethiopia

A survey was conducted on 75 smallholder householders and 205 sample cows selected by random and purposive sampling with the objectives of investigating the challenges, potential and opportunities of production of indigenous Horro and their F1 Jersey cross heifers and cows. The means ± SDs of total farmland, cropland and grazing land holding of individual smallholder householders of the study area was 3.6±3.16, 2.86±2.51 and 0.81±0.89 respectively. The means and SDs of livestock species holdings were 17±11.66, 2.9±3.98, 2.9±4.83, 1.8 ±1.66 and 9.3±8.97 for cattle, sheep, goats, equine and poultry respectively. Breeding method of cattle used was within the proportion of 63.8% and 36.2% for natural mating, and for bull and AI services respectively for on-farm production, while both AI and controlled natural mating were used in the Research Center. The means±SD of NSPC for Horro and their Jersey crossbred heifers was 2.1±1.09 and 1.7±0.94 respectively, where NSPC was significantly influenced by breed of cattle at P<0.05. The overall mean ± SE milk off-take per cow per day for local and crossbred cows were 1.5±0.01 and 5.02±0.12 litres, respectively. Feeding management, breed of animal and site of production significantly influenced milk productivity at P<0.001 both in wet and dry seasons of the year

Postoperative Nosocomial Infections and Antimicrobial Resistance Pattern of Bacteria Isolates among Patients Admitted at Felege Hiwot Referral Hospital, Bahirdar, Ethiopia

Background: Nosocomial infection constitutes a major public health problem worldwide. Increasing antibiotic resistance of pathogens associated with nosocomial infections also becomes a major therapeutic challenge for physicians. Thus, the aim of this study was to identify post operative bacterial infections and determine their current antimicrobial resistance to commonly prescribed drugs.Methods: A cross sectional study was conducted on patients under gone operation from October 2010 to January 2011 and followed for development of clinical signs and symptoms of surgical site and blood stream infection until the time of discharge. Structured questionnaire was used to collect socio demographic characteristics. Wound swab and venous blood samples were collected and processed for bacterial isolation and antimicrobial susceptibility testing following standard bacteriological techniques.Results: Out of 294 patients who had clean and clean-contaminated operation, 10.9% were confirmed of bacterial nosocomial infections. The rate of nosocomial infections among clean and clean-contaminated operations was 3.3% and 12.8% respectively. Nosocomial surgical site and blood stream infection rate was 10.2% and 2.4% correspondingly. A total of 42 bacterial pathogens were identified of which S. aureus was the leading isolates accounting 26.2% followed by E. coli and Coagulase negative Staphylococcus species each 21.4%. Nearly 100% of Gram positive and 95.5% of Gram negative bacterial isolates showed resistance against two or more antimicrobial drugs.Conclusions: Multiple drug resistance of isolates to antimicrobials was alarmingly high so that any empirical prophylaxis and treatment needs careful selection of effective drugs. To minimize such infections, adherence of strict aseptic surgical procedures and proper management of wounds is required

THE ROLE OF RISK ASSESSMENT IN MANAGING RISK

Risk and Uncertainty,

Technology validation and transfer

As farming in Ethiopia is heavily dependent on animal traction, technologies that are based on this power source were envisaged to be appropriate for better management of Vertisols. Hence, the Joint Vertisol Project (JVP) began research on improved Vertisol technology that included 1) the use of an animal-drawn broadbed maker (BBM) to facilitate surface drainage and 2) the use of appropriate seeds, fertiliser and early planting. The aim of the technology verification and transfer were to verify the economic viability and acceptability of the BBM/Vertisol technology package and to popularies the technology so as to encourage large-scale adoption. A comparison of economic returns from crop grown with Vertisol technology package and traditional methods in selected Ethiopian highlands

Assessment of Nutritional Practices of Pregnant Mothers on Maternal Nutrition and Associated Factors in Guto Gida Woreda, East Wollega Zone, Ethiopia

Nutrition is a fundamental pillar of human life, health and development throughout the entire life span. The nutrition requirement varies with respect to age, gender and during physiological changes such as pregnancy. Pregnancy is a critical phase in a woman's life, when the  expectant mother needs optimal nutrients of superior food qualities tosupport the developing fetus. The aim of this study was to assess the practices of pregnant mothers on maternal nutrition and associated factors in Guto Gida Woreda, East Wollega Zone, Ethiopia. The study was  conducted during January to June of the year 2013, using quantitative cross-sectional descriptive study on a sample of 422 pregnant women and supplemented by qualitative study (focus group discussion).The quantitative data were analyzed using SPSS for windows version (16.0). Multiple logistic regression was run to assess factors that were associated with the dependent variable at P<0.05 and to control the confounders. Finally, the result of the study was presented using narratives and tables. This research showed only 33.9% of the respondents were found to have good nutritional practices during their pregnancy. There was a positive significant relation between information about nutrition and family size and nutritional practices of mothers during pregnancy (P<0.001). The practices of pregnant mothers about maternal nutrition were relatively low in this study. Information about nutrition and family size of mothers had a  positive significant relation with mothers’ nutrition practices in the study area. Hence, the government in collaboration with concerned bodies should focus on nutritional education and information about nutrition to increase the practices of pregnant mothers on maternal nutrition during pregnancy in the study area

Epidemiology and economic importance of fasciolosis of domestic ruminants in selected districts of Tigray Region, Ethiopia

An epidemiological study on fasciolosis of domestic ruminants was conducted in four Districts of Tigray Regional State to determine prevalence, identify Fasciola species, assess risk factors and evaluate economic loss. A total of 1708 domestic ruminants were sampled for coprological investigation; in addition 236  slaughtered ruminants were examined at post mortem. The overall prevalence of  fasciolosis in domestic ruminants was 21.2% (95% CI: 15.8-26.9%) and 32.6% (95% CI: 29.7–35.6%) based on coprology and post mortem examinations, respectively. The prevalence in cattle, sheep and goats was 25.3%, 35.7% and 11.4% respectively, based on coprology. The highest prevalence was recorded in Ofla District (41.9%) and the lowest in Alamata District (10.8%). The prevalence was higher in the highland (67.9%) than the midland (17.4%) and the lowland (14.4%); aged animals, and in poor than good body condition in all species. The  prevalence of F. hepatica was 73.1% and 62.7%, and F. gigantica 26.9% and 37.3% by egg and fluke examination, respectively. Statistically significant difference was observed in prevalence among districts, animal agro-ecology, age, and Fasciola species (p<0.05); while no significant association was observed between sexes in animal species (p>0.05). The odd of having fasciolosis in the highland than the lowland was more than 4 times higher (OR= 4.77), similarly the risk in sheep compared with goats was higher by more than 4 times (OR=4.33). During the five years period, out of 11,966 inspected livers, 22.62% were condemned due to fasciolosis. The annual direct and indirect economic loss incurred due to fasciolosis in the study area was estimated to be 286,536.21 Ethiopian Birr (31837.36 USD). Out of the total losses 80.9% was from cattle. The present study revealed a high infection of domestic ruminants by Fasciola species especially in the highland resulting in huge economic losses, hence, intervention to mitigate fasciolosis is required.Keywords: Coprology, Fasciola spp, Risk factors, Post-mortem, Prevalence, Tigray Regio