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Heterogeneous Trends of precipitation Extremes in Recent Two Decades over East Africa

Journal of Meteorological Research 2021年第6期35卷 1057-1073页

作者： Zacharia Florence MTEWELE Xiyan XU Gensuo JIA Key Laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China university of Chinese Academy of sciences Beijing 100049China physics Department University of Dares SalaamDares Salaam P.O.Box 35063Tanzania

East Africa is so vulnerable to the impacts of precipitation extremes varying from frequent floods to prolonged ***,systematic regional assessment of precipitation extremes across seasons has received little attention,and most previous studies of precipitation extremes have employed many indices and sparse gauge observations giving marginalized *** this study,we use three precipitation extreme indices to examine the intensity of the highest single-day rainfall record(rx1day),prevalence of very heavy rainfalls(r30mm),and persistence of successive wet days(cwd)at both annual and seasonal scales over recent two decades(1998-2018)based on the Tropical Rainfall Measuring Mission(TRMM)Multisatellite precipitation Analysis *** results show that the most intensive and frequent precipitation extremes are noticeable from January to May across the areas extending from Madagascar to the Tanzanian coastal *** areas also exhibit patches of significant increasing trends in frequency,duration,and intensity of precipitation extremes annually and ***,significant declines in frequency and intensity of precipitation extremes are observed from western Ethiopia to Congo-Uganda,especially in *** october-December season witnesses higher interannual variability amounting to overall weak and less significant *** subregional assessment shows overall declining intensity and frequency of precipitation extremes in northern part of the study *** wetness duration increased,with persistence of moderate wet days and slight reduction of severe *** study unveils higher susceptibility of the East African region to the widely observed hotspots of precipitation extremes posing threats to food security,water resource,and human *** region should consider upscaling irrigation schemes in addition to planning resilient and supportive infrastructures to withstand the upsurging precipitation extremes,especially al

关键词： precipitation extremes East Africa extreme indices Tropical Rainfall Measuring Mission(TRMM) climate extremes

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Hybrids production as a potential method to control prolific breeding in tilapia and adaptation to aquaculture climate-induced drought

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Aquaculture and Fisheries 2022年第6期7卷 647-652页

作者： Kulwa Mtaki Samwel Mchele Limbu Aviti John Mmochi Matern S.p.Mtolera institute of marine sciences P.O.Box 668University of Dar es SalaamZanzibarTanzania Department of Aquaculture Technology School of Aquatic Sciences and Fisheries TechnologyUniversity of Dar es SalaamP.O.Box 60091Dar es SalaamTanzania East China Normal university Department of BiologySchool of Life SciencesLaboratory of Aquaculture Nutrition and Environmental Health500 Dong Chuan Road200241ShanghaiChina

Establishing suitable salt tolerant all-male tilapia strains with fast growth rate is a crucial requirement for successful euryhaline farming required for controlling prolific breeding and as an adaptation to the effect of climateinduced *** study assessed the percentage of tilapia male hybrids,their growth performance and survival rate produced by crossing female Nile tilapia(oreochromis niloticus)and male Rufiji tilapia(oreochromis urolepis urolepis)at different *** fingerlings were reared for 70 days in triplicate concrete tanks(1 m3),each stocked with 15 fish weighing 1.62±0.03 g,1.69±0.02 g and 1.41±0.06 g exposed to 2,15 and 35 ppt salinities,*** was done by adding seawater to freshwater at a rate of 2 ppt per day for 18 *** sexing was done by visual assessment of the genital papilla followed by rearing the hybrids for six months to observe *** showed that,the cross between ***(female)and *** urolepis(male)produced hybrids that were all-males without any reproduction within six months post hybrid*** hybrids reared at a salinity of 2 ppt had higher growth performance than those reared at 15 and 35 ***,hybrids cultured at 15 ppt had significantly higher growth performance than those reared at 35 *** the hybrids produced had survival rates of 100%.This study indicated that,all-male tilapia produced by crossing between ***(female)and ***(male)can be used by fish farmers as alternative species for mariculture development to control prolific breeding and as an adaptation strategy to climate change.

关键词： Monosex culture Hybridization Mariculture All-male hybrids Aquaculture climate-induced drought

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Investigating the Effect of Winds and Storms on Shoreline Erosion along the Coast of Tanzania

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Journal of Shipping and ocean Engineering 2013年第1期3卷 61-69页

作者： Shigalla Mahongo1 Yohanna Shaghude Tanzania Fisheries Research institute P.O. Box 9750 Dares Salaam Tanzania institute of marine sciences University of Dar es Salaam P.O. Box 668 Zanzibar Tanzania

Wind data spanning 28 years （1977-2004） from four meteorological stations （Tanga, Zanzibar, Dar es salaam and Mtwara） were analyzed to elucidate the effect of winds on coastal erosion along the coast of Tanzania. The investigation entailed wavelet analysis of the time series of winds which were related with past erosion events at each site. The study also analyzed qualitatively the incidences of tropical storms in relation to coastal erosion events along the coast. The results revealed that most of the critical erosion incidents in the past few decades were associated with periods of occurrence of extreme wind speeds and tropical storms. Furthermore, the results indicated that the wind speeds and the frequency and intensity of tropical storms had generally been increasing during the past three decades. The findings were consistent to those recently reported for the coast of Dar es salaam. The increasing trends of winds and storms are considered to have direct impact on the wave climate with increased risk of shoreline wave-induced erosion that is already affecting relatively many parts of Tanzania.

关键词： coastal erosion shoreline change winds tropical cyclones Tanzania.

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西印度洋地区科学论坛的发展

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人类环境杂志 1998年第8期27卷 771-772页

作者： M.Kyewalyanga Julius Francis Ron Johnstone 张永桂 WIoMSA Secretariat p.o.box 3298 Zanzibar Tanzania institute of marine sciences university of dares salaam p.o.box 668 Zanzibar Tropical Ecology Zoology Department Stockholm university S-106 91 Stockholm Sweden

背景在全世界范围内,科学团体普遍因不能以一个统一的声音来表述自身,或因不能开发科学能力以留意自身的感知和洞察力而深感困惑。这种现象对于环境科学家尤为真切,且在发展中国家更为突出。西印度洋海洋科学协会(WIoMSA)的成立即旨在... 详细信息

背景在全世界范围内,科学团体普遍因不能以一个统一的声音来表述自身,或因不能开发科学能力以留意自身的感知和洞察力而深感困惑。这种现象对于环境科学家尤为真切,且在发展中国家更为突出。西印度洋海洋科学协会(WIoMSA)的成立即旨在试图解决东非和西印度洋地区出现的上述问题,其目的在于推动各种海洋科学的健全和有效发展。

关键词：海洋科学科学发展科学发展西印度洋地区

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Seasonal prediction of Tropical Cyclones and Storms over the Southwestern Indian ocean Region Using the Generalized Linear Models

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Atmospheric and Climate sciences 2023年第2期13卷 103-137页

作者： Kombo Hamad Kai Yohanna Wilson Shaghude Christian Bs Uiso Agnes Laurent Kijazi Sarah osima Sara Abdalla Khamis Asya omar Hamad Tanzania Meteorological Authority (TMA) and institute of marine sciences (IMS) University of Dar es Salaam (UDSM) Zan-zibar Tanzania Department of physics University of Dar es Salaam (UDSM) TMA Zanzibar Tanzania Department of Natural sciences State University of Zanzibar Zanzibar Tanzania

Tropical cyclones (TCs) and storms (TSs) are among the devastating events in the world and southwestern Indian ocean (SWIo) in particular. The seasonal forecasting TCs and TSs for December to March (DJFM) and November to May (NM) over SWIo were conducted. Dynamic parameters including vertical wind shear, mean zonal steering wind and vorticity at 850 mb were derived from NoAA (NCEp-NCAR) reanalysis 1 wind fields. Thermodynamic parameters including monthly and daily mean Sea Surface Temperature (SST), outgoing Longwave Radiation (oLR) and equatorial Standard oscillation Index (SoI) were used. Three types of poison regression models (i.e. dynamic, thermodynamic and combined models) were developed and validated using the Leave one out Cross Validation (LooCV). Moreover, 2 × 2 square matrix contingency tables for model verification were used. The results revealed that, the observed and cross validated DJFM and NM TCs and TSs strongly correlated with each other (p ≤ 0.02) for all model types, with correlations (r) ranging from 0.62 - 0.86 for TCs and 0.52 - 0.87 for TSs, indicating great association between these variables. Assessment of the model skill for all model types of DJFM and NM TCs and TSs frequency revealed high skill scores ranging from 38% - 70% for TCs and 26% - 72% for TSs frequency, respectively. Moreover, results indicated that the dynamic and combined models had higher skill scores than the thermodynamic models. The DJFM and NM selected predictors explained the TCs and TSs variability by the range of 0.45 - 0.65 and 0.37 - 0.66, respectively. However, verification analysis revealed that all models were adequate for predicting the seasonal TCs and TSs, with high bias values ranging from 0.85 - 0.94. Conclusively, the study calls for more studies in TCs and TSs frequency and strengths for enhancing the performance of the March to May (MAM) and December to october (oND) seasonal rainfalls in the East African (EA) and Tanzania in particular.

关键词： Tropical Cyclones and Storms Frequency Thermodynamic and Dynamic Models Skill Scores TCs/TSs Variability and Verification Leave one out Cross Validation

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Effect of Geographical location on yield and chemical composition of essential oils from three Eucalyptus species growing in Tanzania

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Asian Journal of Traditional Medicines 2019年第1期14卷 1-12页

作者： Ismail Almas Ester Innocent Francis Machumi William Kisinza institute of Traditional Medicine Muhimbili University of Health and Allied Sciences P. O. Box 65001 Dares Salaam Tanzania National institute for Medical Research (NIMR) Amani Research Centre P. O. Box 81 Muheza Tanzania

Chemical composition of the essential oils (Eos) is dependent on the plant species and varieties, and within the same variety, from geographical region. Knowledge of the factors that determine the chemical variability and yield for each species are very important in particular for commercially important species, to optimize the conditions that may affect yields and quality of essential oils. In addition to the commercial importance of the variability in yield and composition, the possible changes are also important when the essential oils and volatiles are used as chemotaxonomic tools. Therefore it is important to characterize essential oils native to Tanzania for commercial and therapeutic purpose. In the present study we investigated the variation in the yield and chemical composition of the essential oils isolated from air dried leaves of three Eucalyptus species namely Eucalyptus saligna, Eucalyptus citriodora and Eucalyptus camaldulensis collected from two different regions of Tanzania namely Morogoro and Lushoto. The steam-distilled essential oil content of E. saligna, E. citriodora and E. camaldulensis Morogoro were 0.6%(v/w), 1.68%(v/w) and 0.80%(v/w) respectively while from Lushoto are 0.30%, 1.22 and 0.36%(v/w) respectively. Using GC/MS,α-pinene (46.72%) and p-cymene (43.61%) were identified as the most abundant chemical constituents of E. saligna from Morogoro and Lushoto respectively. Citronellal (82.24% and 60.41% respectively) is the main constituents of E. citriodora from Morogoro and Lushoto respectively while p-cymene (52.59% and 64.02%) is the main constituents of E. camaldulensis.

关键词： E. saligna E. camaldulensis E. citriodora chemical composition geographical locations

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桑给巴尔海峡的沉积物分布和输送

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人类环境杂志 1995年第7期24卷 519-522页

作者： Yohanna W.Shaghude Kjell o.Wanns 郑斯中 institute of marine sciences university of Dar es salaam Dept.of Geology and Geochemistry Stockholm university

引言坦桑尼亚的海岸带是一条沿着本土海岸的狭长地带,它包括三个岛屿,即奔巴岛、桑给巴尔岛和马菲亚岛。海岸的高原以厚的沉积岩为特征,断层大致呈南北方向。晚期地壳构造的发育影响了现在陆上和海内的地貌。桑给巴尔海峡的长度大约为12... 详细信息

引言坦桑尼亚的海岸带是一条沿着本土海岸的狭长地带,它包括三个岛屿,即奔巴岛、桑给巴尔岛和马菲亚岛。海岸的高原以厚的沉积岩为特征,断层大致呈南北方向。晚期地壳构造的发育影响了现在陆上和海内的地貌。桑给巴尔海峡的长度大约为120km,宽约35km(图1)。海峡底部以水的深度浅(10～50m)为特征,具有延伸的沙洲和有礁结构的小珊瑚台地。孤立的小礁石结构(块礁)也是常见的。

关键词：坦桑尼亚桑给巴尔海峡海峡沉积物

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pharmacognostic and phytochemical studies as an invaluable approach for correct identification of medicinal plants:The case of Artemisia vulgaris *** for Artemisia annua *** Western Uganda

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TMR Integrative Medicine 2023年第4期7卷 1-13页

作者： Ivan Kahwa Clement olusoji Ajayi Reenu Yadav Nagendra Singh Chauhan Kamal Shah Abdelgadir Alamin Abdelgadir Efrata Ashuro Shegena Salome Daniel Timothy omara John Baptist Asiimwe Hilda Ikiriza Shabnoor Iqbal Casim Umba Tolo Anke Weisheit patrick Engeu ogwang pharm-BioTechnology and Traditional Medicine Centre Mbarara University of Science and TechnologyP.O.Box 1410MbararaUganda Department of pharmacy Faculty of MedicineMbarara University of Science and TechnologyP.O.Box 1410MbararaUganda Department of pharmacy IES UniversityBhopal-462044Madhya PradeshIndia Drugs Testing Laboratory Avam Anusandhan Kendra Raipur(CG)492010India institute of pharmaceutical Research GLA UniversityMathuraUttar Pradesh 281406India Department of pharmacognosy Faculty of PharmacyUniversity of GeziraP.O Box 20Wad MadaniSudan Department of pharmaceutics and pharmacy practice Kampala International UniversityP.O.Box 9790Dares SalaamTanzania institute of Chemistry of Renewable Resources Department of ChemistryUniversity of Natural Resources and Life Sciences Vienna(BOKU)Konrad-Lorenz-Straße 243430Tulln an der DonauAustria Aga Khan university P.O.Box 8842KampalaUganda Department of Biology Mbarara University of Science and TechnologyP.O.Box 1410MbararaUganda Department of Zoology Government College UniversityFaisalabadPunjab 38000Pakistan

Background:Different parts of Artemisia vulgaris L.(***)are ethno-medicinally used as an emmenagogue and for the treatment of ailments such as malaria fever,ulcers,and ***,anecdotal evidence shows that the plant is often substituted for Artemisia annua L.(***)by herbalists in Western Uganda due to similarities in their *** of medicinal plants and mislabelling of herbal products have been incriminated in toxicity and adverse health outcomes in traditional medicine *** safety continues to be a major issue with the use of herbal remedies,it becomes imperative therefore that medicinal plants should be correctly ***:This study focused on investigating the macroscopic,microscopic,physicochemical characteristics and phytochemical composition of *** leaves compared to *** to ease its correct ***:The results showed that there are some colour differences between the leaves of the two species,with a close arrangement of microscopic features but different leaf *** leaves of the two Artemisia species had similar tastes,but their shapes and colours(greenish-yellow for *** and dark green for ***)can be used by the local community to distinguish between *** artemisinin content was higher in *** leaves(1.72%)than in ***(1.43%),but the reverse was observed for the total flavonoid ***:This observation could justify the change in the use of *** by the indigenous community in western *** studies should consider the pharmacognostic comparison of *** with other species in the genus Artemisia and the use of molecular techniques such as DNA barcoding.

关键词： Artemisinin traditional medicine misidentification microscopic studies

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