6 research outputs found

    Lichens in Mountain Rainforests of Tanzania : Studies of Usnea and Calicioids

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    Lichens occur in various habitats. They often have narrow niches and are sensitive to environmental changes leading to their use as bioindicators of environmental disturbances and conditions; air and heavy metal pollution, agricultural toxins, assessing forest continuity and drought tolerance. Lichenological studies in Africa, particularly in Tanzania, have been scarce, and those available have been mainly based on morphology and chemistry data.   The aim of my doctorate was to investigate lichens, in particular Usnea and calicioid lichens in mountain rain forests in Tanzania, using both traditional and molecular approaches. Paper I and II explored Usnea subgenus Eumitria. In paper I, molecular, morphological and chemical methods were utilized. A phylogeny of Eumitria from Tanzania based on a four-markers data set supported monophyly of Eumitria, where sixty-two new sequences were reported. In paper II additional specimens of the Usnea pectinata aggregate from Tanzania and São Tomé and Príncipe were studied, and forty-two specimens were examined by an integrative approach (molecular, morphological, chemical data). The U. pectinata aggregate was monophyletic, containing several subclades, some characterized morphologically and chemically.    Paper III and IV focused on calicioids. Paper III summed up earlier information on Tanzanian calicioids along with new discoveries (twenty-six species), with notes on their habitats and distributions. Chaenothecopsis kilimanjaroensis was described as new, Chaenotheca hispidula and Pyrgillus cambodiensis new to Africa: Calicium lenticulare and Chaenothecopsis debilis new to Tanzania. In paper IV, Coniocybe was revised and emended to include along with its type C. furfuracea, also C. brachypoda and C. confusa. A three marker phylogeny was used to infer its phylogenetic position and Coniocybe eufuracea was described as new. This thesis contributes to the knowledge of the lichens in Tanzania and Africa at large by building capacity in lichenology and its applications for future research. It provided integrated data for Usnea species from Africa, adding to the knowledge of this difficult group (only two sequences of Usnea from Africa have previously been published). It provided new information on calicioid lichens in Tanzania and by uncovering a rich diversity in both of the groups studied provided a foundation for further investigations of lichen biodiversity

    Lichens in Mountain Rainforests of Tanzania : Studies of Usnea and Calicioids

    No full text
    Lichens occur in various habitats. They often have narrow niches and are sensitive to environmental changes leading to their use as bioindicators of environmental disturbances and conditions; air and heavy metal pollution, agricultural toxins, assessing forest continuity and drought tolerance. Lichenological studies in Africa, particularly in Tanzania, have been scarce, and those available have been mainly based on morphology and chemistry data.   The aim of my doctorate was to investigate lichens, in particular Usnea and calicioid lichens in mountain rain forests in Tanzania, using both traditional and molecular approaches. Paper I and II explored Usnea subgenus Eumitria. In paper I, molecular, morphological and chemical methods were utilized. A phylogeny of Eumitria from Tanzania based on a four-markers data set supported monophyly of Eumitria, where sixty-two new sequences were reported. In paper II additional specimens of the Usnea pectinata aggregate from Tanzania and São Tomé and Príncipe were studied, and forty-two specimens were examined by an integrative approach (molecular, morphological, chemical data). The U. pectinata aggregate was monophyletic, containing several subclades, some characterized morphologically and chemically.    Paper III and IV focused on calicioids. Paper III summed up earlier information on Tanzanian calicioids along with new discoveries (twenty-six species), with notes on their habitats and distributions. Chaenothecopsis kilimanjaroensis was described as new, Chaenotheca hispidula and Pyrgillus cambodiensis new to Africa: Calicium lenticulare and Chaenothecopsis debilis new to Tanzania. In paper IV, Coniocybe was revised and emended to include along with its type C. furfuracea, also C. brachypoda and C. confusa. A three marker phylogeny was used to infer its phylogenetic position and Coniocybe eufuracea was described as new. This thesis contributes to the knowledge of the lichens in Tanzania and Africa at large by building capacity in lichenology and its applications for future research. It provided integrated data for Usnea species from Africa, adding to the knowledge of this difficult group (only two sequences of Usnea from Africa have previously been published). It provided new information on calicioid lichens in Tanzania and by uncovering a rich diversity in both of the groups studied provided a foundation for further investigations of lichen biodiversity

    Crustose Calicioid Lichens and Fungi in Mountain Cloud Forests of Tanzania

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    A total of 26 crustose calicioid lichens and fungi were found in Tanzania. Most of them belong to a group of species with wide distributions in cool areas of both hemispheres and occasional occurrence in high mountains at low latitudes. In Tanzania calicioids mainly occur in the middle and upper forest zones and their niches are found on the bark of old trees and on lignum, most of them restricted to mountain cloud forests. Calicioids are rare and often red-listed, and are also bioindicators of long forest continuity. Consequently, they form an important biota in mountain cloud forests and deserve attention in the context of preserving biodiversity and developing conservation policies. One new species, Chaenothecopsis kilimanjaroensis, is described. Chaenotheca hispidula and Pyrgillus cambodiensis are reported as new to Africa and Calicium lenticulare and Chaenothecopsis debilis are reported as new to Tanzania

    Phylogeny of the subgenus Eumitria in Tanzania

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    Several Usnea species in subgenus Eumitria (Parmeliaceae, lichenized Ascomycota) have been described from East Africa in the past decades. These have been based on morphology and chemistry data while molecular studies remain very limited. In this paper we are for the first time publishing phylogenetic analyses along with morphological and chemical data for Eumitria. ‬A total of 62 new sequences of Eumitria (26 ITS, 20 nuLSU, 6 MCM7, 10 RPB1) were generated in this study. nuLSU, MCM7 and RPB1 sequences are here for the first time reported for U. baileyi. A phylogeny of subgenus Eumitria from Tanzania based on Bayesian and maximum likelihood analyses of a concatenated four-loci data set is presented, confirming the monophyly of Eumitria. Further, secondary chemistry and variation in characters, such as the pigmentation of the central axis and branch shape were investigated.Swedish International Development Cooperation Agency (SIDA) – UDSM-SIDA, Project No. 2221

    Combined production of bioethanol and biogas from peels of wild cassava Manihot glaziovii

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    Cassava peels were pre-treated with alkali, enzyme and in sequential combination of alkali and enzyme, and used for production of bioethanol or biogas, or both (in sequence, bioethanol followed by biogas). The Biogas Endeavour and Automatic Methane Potential Test Systems were used for production of bioethanol and biogas, respectively. The bioethanol yield and volumetric productivity achieved with alkali pre-treatment combined in sequence with enzyme pre-treatment were 1.9 mol/mol and 1.3 g/L/h which was higher than the yield (1.6 mol/mol) and volumetric productivity (0.5 g/L/h) obtained from only enzyme pre-treated peels. Alkali combined in sequence with enzyme was proven to be the best treatment showing a 56% improvement in methane yield compared to the yield from untreated sample. Combined ethanol and methane production resulted in 1.2-1.3-fold fuel energy yield compared to only methane and 3-4-fold compared to only ethanol production. This study therefore provides practical data on the scenario best suited for the harnessing of energy from cassava peels. (C) 2015 Elsevier B.V. All rights reserved

    Preexposure prophylaxis for HIV infection among African women.

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    BACKGROUND: Preexposure prophylaxis with antiretroviral drugs has been effective in the prevention of human immunodeficiency virus (HIV) infection in some trials but not in others. METHODS: In this randomized, double-blind, placebo-controlled trial, we assigned 2120 HIV-negative women in Kenya, South Africa, and Tanzania to receive either a combination of tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) or placebo once daily. The primary objective was to assess the effectiveness of TDF-FTC in preventing HIV acquisition and to evaluate safety. RESULTS: HIV infections occurred in 33 women in the TDF-FTC group (incidence rate, 4.7 per 100 person-years) and in 35 in the placebo group (incidence rate, 5.0 per 100 person-years), for an estimated hazard ratio in the TDF-FTC group of 0.94 (95% confidence interval, 0.59 to 1.52; P=0.81). The proportions of women with nausea, vomiting, or elevated alanine aminotransferase levels were significantly higher in the TDF-FTC group (P=0.04, P<0.001, and P=0.03, respectively). Rates of drug discontinuation because of hepatic or renal abnormalities were higher in the TDF-FTC group (4.7%) than in the placebo group (3.0%, P=0.051). Less than 40% of the HIV-uninfected women in the TDF-FTC group had evidence of recent pill use at visits that were matched to the HIV-infection window for women with seroconversion. The study was stopped early, on April 18, 2011, because of lack of efficacy. CONCLUSIONS: Prophylaxis with TDF-FTC did not significantly reduce the rate of HIV infection and was associated with increased rates of side effects, as compared with placebo. Despite substantial counseling efforts, drug adherence appeared to be low. (Supported by the U.S. Agency for International Development and others; FEM-PrEP ClinicalTrials.gov number, NCT00625404.)
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