Fluoride in black and green tea (Camellia sinensis) infusions in Ethiopia: measurement and safety evaluation

The fluoride contents in the infusions of 21 commercially available Ethiopian and imported black and green tea brands; in leaf and bag forms was determined by a fluoride ion-selective electrode method. Of the samples analyzed twelve were products from Ethiopia and the remaining nine were imported tea brands. The effect of brewing time on fluoride release from tea was assessed. Results showed that fluoride release increased with increasing brewing time (3, 5 and 10 min). Fluoride level after 5 min brewing for black tea leaves, green tea bags, and black tea bags was in the range of 117–682 mg/kg, 111–190 mg/kg and 141–246 mg/kg, respectively. The WHO guideline for daily fluoride intake is 2 mg for children and 4 mg for adults. Assuming that one consumes 4 cups of tea everyday (400 mL) and each cup uses 2.5 g of tea leaves, the daily fluoride intake from black tea leaves may be in the range between 1.11 and 6.82 mg. For the same condition, if consumption of one green tea bag is considered, the fluoride intake can be in the range between 1.00 and 1.38 mg. Similarly, intake from the black tea bags may range from 0.86 to 1.81 mg. Considering the Ethiopian black tea alone, the daily fluoride intake may range from 2.48 to 6.82 mg. Thus according to the WHO recommendation for daily fluoride intake and ignoring other possible sources; the black and green tea bags and imported black tea leaves are safe for all age groups. None of the 10 Ethiopian black tea leaf brands are safe for children but 30% of the analyzed samples are safe for adults.KEY WORDS: Black tea infusion, Green tea infusion, Fluoride intake, Brewing time, Safety evaluation Bull. Chem. Soc. Ethiop. 2010, 24(3), 327-338

Objectives, criteria and methods for using molecular genetic data in priority setting for conservation of animal genetic resources

The genetic diversity of the world!s livestock populations is decreasing, both within and across breeds. A wide variety of factors has contributed to the loss, replacement or genetic dilution of many local breeds. Genetic variability within the more common commercial breeds has been greatly decreased by selectively intense breeding programmes. Conservation of livestock genetic variability is thus important, especially when considering possible future changes in production environments. The world has more than 7500 livestock breeds and conservation of all of them is not feasible. Therefore, prioritization is needed. The objective of this article is to review the state of the art in approaches for prioritization of breeds for conservation, particularly those approaches that consider molecular genetic information, and to identify any shortcomings that may restrict their application. The Weitzman method was among the first and most well-known approaches for utilization of molecular genetic information in conservation prioritization. This approach balances diversity and extinction probability to yield an objective measure of conservation potential. However, this approach was designed for decision making across species and measures diversity as distinctiveness. For livestock, prioritization will most commonly be performed among breeds within species, so alternatives that measure diversity as co-ancestry (i.e. also within-breed variability) have been proposed. Although these methods are technically sound, their application has generally been limited to research studies; most existing conservation programmes have effectively primarily based decisions on extinction risk. The development of user-friendly software incorporating these approaches may increase their rate of utilization

Dimension 5: The Mystery of Dreams

The purpose of my thesis is to make a documentary film that investigates the territory of dreams. My film is a collection of interviews with people whose areas of expertise have given them insights into the significance of dreams. The written component of my thesis gives background on the development of our understanding about the roles dreams play in our lives. I included research from such fields of study as religion, philosophy, psychology, and neurology. I also present the ways in which cinema portrays dreams as well as a discussion about the development and execution of my film. My decision to pursue this project stems from my intention to become a filmmaker as well as from my desire to unveil the mystery of dreams. After all, we spend a third of our lives sleeping

Senior Thesis Proposal

Senior Thesis Proposa

Repair of sub-lethal damage following single and split-dose irradiation using 60co-gamma and p(66)Be neutrons

Thesis (MTech Biomedical Technology)--Cape Peninsula University of Cape Town, 2005In clinical radiotherapy, experiments are performed to determine optimal conditions of the radiation prior to radiotherapy. These experiments focus on the relative biological effectivness(RBE) determination and are predominantly applied in high linear energy transfer (LET) radiations i.e. fast neutrons, as the RBE values for such radiations vary greatly. In general, the RBE of a certain radiation relative to a given reference radiation flCo gamma) varies widely with the energy, dose, dose rate, fractionation, type of tissue and end-point used. Experience with neutron therapy at iThemba LABS has shown that treatment with more fractions and lower doses per fraction may be beneficial for some patients. To calculate the iso-effective treatment dose needed, an appropriate alp ratio for early effects is needed. In this study, the repair of mouse jejunum was measured for split-dose irradiations to determine if a suitable alP ratio for neutrons could be estimated using the known value for gamma rays and the applicable RBE.. Crypt stem cell survival was measured 3.5 days after split-dose exposures to p(66)/Be neutrons and 6OCo gamma rays. Dose response curves for both treatment modalities and for both acute and fractionated exposures were constructed by counting crypts of Leiberkhiin at the base of the villi in haematoxylin and Eosin-stained sections of mouse jejunum. Using a RBE value of 1.64 and an alP ratio of 7Gy noted for tbe fractionated photon exposures, an alP ratio of 11.5 IV could be estimated for neutrons

Concentration and Health Implication of Heavy Metals in Drinking Water from Urban Areas of Tigray Region, Northern Ethiopia

The study was undertaken to assess the status of drinking water quality in the urban areas of the Tigray region, northern Ethiopia. A total of 106 drinking water samples were collected from 16 densely populated urban areas of the region, viz.: Alamata, Korem, Maichew, Adigudom, Abyi-Adi, Hagereselam, Zalambessa, Adigrat, Edagahamus, Firewoini, Wukro, Mekelle, Indaselassie, Axum, Adwa, and Enticho. All the samples were analyzed for six physicochemical parameters such as temperature, conductivity, total dissolved solids (TDS), salinity, pH, and turbidity and ten heavy metals,viz., As, Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, and Zn using standard procedures. The results were compared with other national and international standards. Among the analyzed samples, regarding physicochemical parameters, 84.01 % for electrical conductivity, 47.17 % for TDS and 31.13% for turbidity show concentrations higher than the WHO (2008) recommended values. More than 93.4% of the samples were within the United States Environmental Protection Agency (US EPA) admissible pH limit (6.5-8.5) and all the samples analyzed were within the EU (1998) admissible pH limit (6.5-9.5). All samples contain manganese and copper within the WHO (2008) maximum admissible limit, but arsenic (40.3 %), cadmium (7.46 %), chromium (64.18 %), iron (37.31 %), nickel (7 %), and lead (29.85 %) crossed the maximum admissible and desirable limits recommended by WHO (2008). The maximum admissible limit of cobalt in drinking water is not mentioned by WHO, but all the samples analyzed were found to comply the New Zealand (1000 μg/L) and US EPA (100 μg/L) maximum admissible limits. Although no guideline is set by WHO (2008) for Zinc level in drinking water, of the samples analyzed, 94.02% comply the New Zealand standard and 97.01% comply all the maximum admissible limits referred in the present study. In general, the results of the present study have shown that some of the physico-chemical parameters have shown values higher than the WHO (2008) recommended maximum admissible limits. This is an indication of pollution hazards and weak drinking water treatment practices in the areas, which in turn have important human health implications. This study, therefore, recommends the government and other responsible authorities to take appropriate corrective measures. Key words: Drinking water quality, Heavy metals, Maximum admissible limit, World health organization, Tigra

Traditional knowledge of medicinal plants in Gindeberet district Western Ethiopia. South African

Abstract Ethiopia, is a country characterized by a wide range of climate and ecological conditions, possesses enormous diversity of fauna and flora. Semi-structured interviewees, observation and guided field walks with informants were employed to obtain ethnobotanical data in Gindeberet district, western Ethiopia. A total of 120 informants (84 males and 36 females) were selected purposefully from six sub districts. A total of 26 species of medicinal plants were collected and identified for treating 36 human ailments. The medicinal plant preparations were administered through oral, dermal and nasal routes. Oral application (33 preparations, 67.3%) was the highest and most commonly used route of application followed by dermal application (15 preparations, 30.6%). The most commonly used plant parts for herbal preparations were leaves (28%) and roots (28%) followed by barks (14%) and fruits (14%). Gindeberet district is rich in its medicinal plant composition and the associated indigenous knowledge. Evaluation of the medicinal plants for their efficacy and possible toxicity would be very important

<b>Fluoride in black and green tea (<i>Camellia sinensis</i>) infusions in Ethiopia: measurement and safety evaluation</b>

The fluoride contents in the infusions of 21 commercially available Ethiopian and imported black and green tea brands; in leaf and bag forms was determined by a fluoride ion-selective electrode method. Of the samples analyzed twelve were products from Ethiopia and the remaining nine were imported tea brands. The effect of brewing time on fluoride release from tea was assessed. Results showed that fluoride release increased with increasing brewing time (3, 5 and 10 min). Fluoride level after 5 min brewing for black tea leaves, green tea bags, and black tea bags was in the range of 117–682 mg/kg, 111–190 mg/kg and 141–246 mg/kg, respectively. The WHO guideline for daily fluoride intake is 2 mg for children and 4 mg for adults. Assuming that one consumes 4 cups of tea everyday (400 mL) and each cup uses 2.5 g of tea leaves, the daily fluoride intake from black tea leaves may be in the range between 1.11 and 6.82 mg. For the same condition, if consumption of one green tea bag is considered, the fluoride intake can be in the range between 1.00 and 1.38 mg. Similarly, intake from the black tea bags may range from 0.86 to 1.81 mg. Considering the Ethiopian black tea alone, the daily fluoride intake may range from 2.48 to 6.82 mg. Thus according to the WHO recommendation for daily fluoride intake and ignoring other possible sources; the black and green tea bags and imported black tea leaves are safe for all age groups. None of the 10 Ethiopian black tea leaf brands are safe for children but 30% of the analyzed samples are safe for adults

The status of cattle genetic resources in North Ethiopi: On-farm charcterization of six major cattle breeds

On-farm surveys and characterization of six indigenous north Ethiopian cattle breeds (Afar, Arado, Begait, Fogera, Medenes and Raya) was carried out with the objective of determining the current status of these breeds. Information from a structured questionnaire distributed to 450 farmers, 37 group discussions, field measurements of heart girth and height on 25 males and 25 females from each breed and secondary information were used to carry out the study. Population size of Arado breed increased by more than three fold between 1992 and 1999, while the Raya, Fogera and Begait population decreased by 57, 27 and 67%; between 1981 and 1999 respectively. Three distinctive types were identified within the Afar and Begait breeds with different adaptation and threat levels in relation to changes to the bio-physical and social environment. Overall production and reproduction performance of the breeds in the pastoral production system (Afar and Arado and Fogera breeds of the agro-pastoral and mixed crop/ livestock production systems respectively. Extinction probability for most of the breeds was high, the highest (0.67) being for the Begait breed. On the other hand, except for the initiative taken to evaluate, improve and conserve the Fogera breed at the Metekel and Andasa cattle breedin ranches, there are no institutionalized attempts towards improving and/ or conserving the other breeds