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Physico-Chemical Characteristics Of Storage-Ripened Mango (Mangifera Indica L.) Fruits Varieties Of Eastern Tanzania, O C Othman, G P Mbogo

Tanzania Journal of Science

Two mango (Mangifera indica L.) fruit varieties, Dodo and Viringe, from two localities of Eastern Tanzania, (Muheza in Tanga and Ifakara in Morogoro), were harvested as mature green fruits during early, mid and late season and allowed to ripen while stored at room temperature. The fruits were analyzed for their proximate composition (ash, titratable acidity, crude fat, crude fibre, moisture), reducing and total sugars content, ascorbic acid and total soluble solids content, concentration of four macro elements (Ca, Mg, K, Na) and seven heavy metals (Al, Cd, Cu, Fe, Mn, Pb, Zn). The results showed that the mango fruits had …

Assessment Of Post-Harvest Technologies And Gender Relations In Maize Loss Reduction In Pangawe Village Eastern Tanzania, C P Rugumamu

Tanzania Journal of Science

In this paper the use of gender sensitive technologies in the reduction of post-harvest maize losses at farm level is advocated as a strategy for household food security. The study was conducted in Pangawe village, eastern Tanzania. It employed participatory approaches to investigate farmers’ perceptions on loss management. Storage trials were carried out to determine maize losses caused by insect pests in the sub-villages. Perceptions were analysed qualitatively and quantitatively. ANOVA assessed losses in storage trials. Major post-harvest processes included farm field; en-route; homestead and storage. All activities except winnowing were carried out by both men and women at varying …

Physical And Chemical Composition Of Storage-Ripened Papaya (Carica Papaya L.) Fruits Of Eastern Tanzania, O C Othman

Tanzania Journal of Science

The proximate composition (ash, titratable acidity, crude fat, crude fibre, moisture and sugars), soluble solids, ascorbic acid, polyphenol oxidase activity, macro-nutrients and heavy metal contents of storage-ripened papaya (Carica papaya L.) fruits from Mbezi, Dar es Salaam, Tanzania were determined. The determinations were repeated for early, middle and late-season papaya fruits. The fruits were always harvested at the mature green stage and allowed to ripen during room temperature storage. The results showed that papaya fruits had high moisture content (>85.5%), low acidity (<0.18% c.a.), low crude fat (0.10 g/100 g-edible portion), moderate crude fibre (1.45 g/100 g-edible portion), high ascorbic acid content (>84.5 mg/100 g- fw), moderate total sugars (>13.0%) and soluble solids (>12.9%) content. Early-season …

Monitoring Of Heavy Metal Loading Into The Wetlands South Of Lake Victoria Basin, Nothern Tanzania, M K D Mutakyahwa, J R Ikingura, G Y S Mtui

Tanzania Journal of Science

The paper discusses sources, concentrations and physicochemical parameters of heavy metals of environmental concern in the wetlands of Lake Victoria basin in Tanzania. The metals investigated include copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), chromium (Cr), nickel (Ni), arsenic (As), manganese (Mn), cobalt (Co) and mercury (Hg). These metals are released into the wetlands via weathering and erosion of rock formations, mining operations and industrial activities, discharge of municipal and domestic waste, and use of agrochemicals. The levels of these heavy metals in soil, sediment, water, and biota differ. Wetlands impacted by gold mining activities in the South Lake …

Plants As A Source Of Green Corrosion Inhibitors: The Case Of Gum Exudates From Acacia Species (A. Drepanolobium And A. Senegal), J Buchweishaija

Tanzania Journal of Science

The inhibitive performance of gum exudates from Acacia drepanolobium and Acacia senegal from Tanzania, towards the corrosion of mild steel in fresh water has been investigated. The experimental methods include potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) studies. The results indicate that gum exudates (Acacia drepanolobium and Acacia senegal) exhibit good inhibition characteristics to corrosion on mild steel under fresh water medium and the inhibition efficiency of up to 90.7% and 99.7% respectively was attained at 30 oC. Furthermore, the studies have shown that the inhibition performance remained above 90% on both Acacia exudates independent of the raise in temperature. …

Anti-Mosquito And Antimicrobial Nor-Halimanoids, Isocoumarins And An Anilinoid From Tessmannia Densiflora, Charles Kihampa, Mayunga H.H. Nkunya, Cosam C. Joseph, Stephen M. Magesa, Ahmed Hassanali, Matthias Heydenreich, Erich Kleinpeter

All Peer-Reviewed Publications

The nor-halimane diterpenoid tessmannic acid and its methyl, 2-methylisopropyl and 1-methylbutyl esters, the unusual isocoumarins 8-hydroxy-6-methoxy-3-pentylisocoumarin and 7-chloro-8-hydroxy-6-methoxy-3-pentylisocoumarin, and 5-pentyl-3-methoxy-N-butylaniline were isolated from the stem and root bark extracts of Tessmannia densiflora Harms (Caesalpiniaceae) that showed mosquito larvicidal activity. The structures were determined on interpretation of spectroscopic data. Tessmannic acid and its methyl ester exhibited antibacterial and antifungal activity. The compounds also caused high larvae and adult Anopheles gambiae mosquitoe mortality effects, and stronger mosquito repellency than that shown by the standard repellent DEET, hence indicating Tessmannia species to be potential sources of bioactive natural products. © 2009 Elsevier Ltd. …

The Game Of Conservation: International Treaties To Protect The World’S Migratory Animals, Mark Cioc

Ohio University Press Open Access Books

The Game of Conservation is a brilliantly crafted and highly readable examination of nature protection around the world.

Twentieth-century nature conservation treaties often originated as attempts to regulate the pace of killing rather than as attempts to protect animal habitat. Some were prompted by major breakthroughs in firearm techniques, such as the invention of the elephant gun and grenade harpoons, but agricultural development was at least as important as hunting regulations in determining the fate of migratory species. The treaties had many defects, yet they also served the goal of conservation to good effect, often saving key species from complete …

Detection Of Bovine Tuberculosis By Tuberculin Test And Polymerase Chain Reaction In Van, Turkey, Hasan Solmaz, Zi̇ya İlhan, Abdulbaki̇ Aksakal, Ti̇mur Gülhan, İsmai̇l Hakki Eki̇n

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to identify the presence and prevalence of bovine tuberculosis in the eastern Anatolian border province of Van and its villages and to collect the preliminary data required for programs for the prevention and control of this zoonotic disease. The tuberculin test was performed on 210 cattle. Nasal swab and milk samples were obtained from the animals tested. Three cattle that had a positive tuberculin test also tested positive for the DNA target, a 580-bp fragment of IS6110 specific for members of the Mycobacterium tuberculosis complex. This fragment was also recovered from milk taken from …

The Performance Of Maize Crop During Acid Amelioration With Organic Residues In Soils Of Mtwara, Tanzania, Ae Majule, Jo Omollo

Tanzania Journal of Science

This study evaluated acid ameliorative potential and their effects on maize growth of four organic residues namely wild spikenard, cordia, cowpea and pigeon peas through incubations with or without sulphur. This was done in order to recommend potential organic residue source that could ameliorate soil acidity associated with sulphur dusting. Increased levels of sulphur in the soils reduced the growth and dry matter yields of maize due to intense acidification while maize growth and dry matter yields in soils which organic residues were incorporated was enhanced. Enhancement in maize performance may be a result of reduced soil acidity due to …

Involvement Of Methyltransferases Enzymes During The Energy Metabolism Of The Anaerobic Archaeon Methanosarcina Semesiae Sp. Nov., Tj Lyimo

Tanzania Journal of Science

The methyl group transfer from dimethylsulfide (DMS), trimethylamine and methanol to 2-mercaptoethanesulfonic acid (coenzyme M) were investigated from cell extracts of Methanosarcina semesiae sp. nov. to evaluate whether the enzyme systems involved were constitutive or inductive. The extracts from cells grown on DMS exhibited methanogenic activity exclusively with DMS and methanethiol. Likewise when cells were pre-grown on trimethylamine or methanol the extracts only produced methane from the respective metaboilic substrate. Dimethylsulfide:methyl-coenzyme M transferase activity was dependent on ATP, but hydrogen did not stimulate activity. The fact that ATP could be replaced by the reductant Ti(III)-citrate indicates that reductive activation of …

Delineating The Jurassic To Mid Cretaceous Part Of The Pacific Apparent Polar Wander Path, Dcp Masalu

Tanzania Journal of Science

The Jurassic to Mid-Cretaceous apparent polar wander path of the Pacific plate irrespective of ages have been delineated. Two poles have been established: one pole, which is relatively older than the other, is at 75.01°N/287.5°E (α = 6.9°) and the other pole is at  61.0°N°/304.7°E (!95 = 4.5°). These results indicate that the Pacific plate drifted southward during the Jurassic to Early-Cretaceous period. Additionally, the results demonstrate that there is an apparent consistent correspondence between changes of plate motion and significant shifts of the Jurassic to Mid-Cretaceous apparent polar wander path

Occurrence Of Digenean Larvae In Freshwater Snails In The Ruvu Basin, Tanzania, G. Nkwengulila, E. S. P. Kigadye

Tanzania Journal of Science

A survey was carried out on digenean larvae infecting freshwater snails in five habitats in Dar es Salaam, Ruvu and Morogoro. 9424 snails belonging to 12 species from five families were examined for digenean infection from July 1996 – June 1997. 20 morphologically distinguishable cercariae were recovered. Multiple infections were not recorded. While the general prevalence of digeneans in snails was low (3.5%), variations occurred between seasons, among habitats and snail host species. Prevalence was high during the dry season but low in the rain season. Among habitats, highest prevalence was recorded at Kinondoni pond and lowest at Ruvu ponds, …

Abundance And Diversity Of Seagrass And Macrofauna In The Intertidal Areas With And Without Seaweed Farming Activities In The East Coast Of Zanzibar, Thomas J Lyimo, Esther F Mvungi, Yunus D Mgaya

Tanzania Journal of Science

The diversity and abundance of seagrass and associated macrofauna were studied in transects with and without seaweed farms at Chwaka Bay and Jambiani, in the East Coast of Zanzibar. Eight seagrass species, namely Cymodocea rotundata, Cymodocea serrulata, Thalassia hemprichii, Thalassodendron ciliatum, Syringodium isoetifolium, Halodule uninervis, Halophila ovalis and Enhalus acoroides were recorded in the transects. The mean total biomass of seagrass at Chwaka Bay ranged from 142.4 ± 70.71 to 1652 ± 772.7 g dw/m2 and 212.9 ± 146.2 to 1829 ± 1692 g dw/m2 in station with and without seaweed farms, respectively. At Jambiani, the mean total biomass ranged …

Seed Longevity Of Dominant Plant Species From Degraded Savanna In Semi-Arid Tanzania, Hvm Lyaruu

Tanzania Journal of Science

Artificially buried seeds were followed by periodic exhumation and germination during 21 months in Kondoa Irangi Hills, central Tanzania. Viable seeds from thirteen selected species were buried in polythene envelopes at a depth of 15 cm below woodland vegetation. Lethal germination, fungal decay and insect infestation were singled out as the most important contributors to loss of viability among seeds. Hierarchical clustering based on a seed’s mean viability, seed shape and presence or absence of dispersal appendages, produced three distinct groups: (1) non-dormant seeds (2) seeds with enforced dormancy and (3) seeds with seed coat imposed dormancy. The low decay …

Absolute Migration Of Pacific Basin Mid-Ocean Ridges Since 85 Ma And Their Tectonic Implications For The Pacific Plate, Dcp Masalu

Tanzania Journal of Science

Mid-ocean ridges are major physiographic features that dominate the world seafloor. Their absolute motion and tectonics are recorded in magnetic lineations they created. The absolute migration of mid-ocean ridges in the Pacific basin since 85 Ma and their tectonic implications was investigated in this work and the results indicates that at about anomaly 21 (47 Ma) theEast Pacific Rise (EPR) and Juan de Fuca ridge experienced an abrupt change in their migration direction that persisted until about anomaly 6 (20 Ma), probably due to changes in subductionzone configuration in the northern Pacific. This may represent a period of tectonic instability …

Vertical Distribution Of Spiders (Araneae) On A Tropical Island, Eric Brown

Independent Study Project (ISP) Collection

The distribution of spiders into vertical layers was studied on Misali Island. In particular, differences in diversity, species richness, abundance, and body length were analyzed. A variety of collection methods were used in order to capture as many different species as possible from three levels of forest: leaf litter, groundcover (up to 1m), and understory (up to 3m). After being sorted to the morphospecies level, the spiders were cataloged and several statistical tests were run. These tests show that spiders do show species-level stratification between different levels of forest. They also pointed towards a particularly firm dividing line between species …

A New Species Of Giant Sengi Or Elephant-Shrew (Genus Rhynchocyon) Highlights The Exceptional Biodiversity Of The Udzungwa Mountains Of Tanzania, F Rovero, G B. Rathbun, A Perkin, T Jones, David O. Ribble, C Leonard, R R. Mwakisoma, N Doggart

Biology Faculty Research

A new species of sengi, or elephant-shrew, is described. It was discovered in the northern Udzungwa Mountains of Tanzania in 2005. Sengis (Order Macroscelidea, super-cohort Afrotheria) include four genera and 15 species of mammals that are endemic to Africa. This discovery is a significant contribution to the systematics of this small order. Based on 49 camera trap images, 40 sightings and five voucher specimens, the new sengi is diurnal and distinguished from the other three species of Rhynchocyon by a grizzled grey face, pale yellow to cream chest and chin, orange-rufous sides, maroon back and jet-black lower rump and thighs. …

New Strategy For The Search Of Natural Biologically Active Substances., Vyacheslav Dushenkov, Ilya Raskin

Publications and Research

The modern pharmaceutics actively screens an immense diversity of substances occurring in plants and other natural resources in the search for new effective medicinal agents. The Global Institute for Bioexploration (GIBEX) established by joint efforts of Rutgers University and the University of Illinois (United States) represents the organizational core of international scientific community whose activity is directed towards the search and development of new medicinal preparations from natural raw materials. The basis of GIBEX activity is the transfer of modern screening technologies to countries and geographical regions characterized by remarkable biodiversity. The GIBEX goals are to encourage the search for …

An Assessment Of Methods For Sampling Carabid Beetles (Coleptera: Carabidae) In A Montane Rain Forest, B. A. Nyundo, J. G. Yarro

Tanzania Journal of Science

Pitfall trapping is the traditional method for sampling carabid beetles and other grounddwelling invertebrates. Tests were carried out in the Udzungwa Mountains National Park between March 1999 and July 2000. Results indicated that pitfall traps were less efficient compared to manual searching methods, both in terms of relative abundance and species richness of carabid beetles. The results are discussed in the context of biodiversity inventories in theEastern Arc Mountains.

Determination Of Elemental Composition Of Air Particulates And Soils In Khartoum Area, F. I. Habbani, E. M. Eltahir, A. S. Ibrahim

Tanzania Journal of Science

Investigations were carried out for elemental composition of air particulates in the background air and near roadsides in Khartoum area. Investigations were also performed for the elemental composition of soils at the same locations. A cyclone and a dichotomous virtual impactor wereused to measure the air particulates. The cyclone was adjusted to collect particles having an aerodynamic diameter of 2.5!m. The virtual impactor, through its fine channel, was capable of collecting airborne particles with an aerodynamic diameter of 2.5 μm. Energy Dispersive X-Ray Fluorescence (EDXRF) analysis was used to study the elemental concentrations of the air and soil samples. The …

Assessment Of Fecal Bacteria Contamination In Sewage And Non-Sewage Impacted Mangrove Ecosystems Along The Coast Of Dar Es Salaam, A. A. Abbu, Thomas J. Tj Lyimo

Tanzania Journal of Science

Microbiological quality of the intertidal pool water was evaluated in sewage impacted (Mtoni Kijichi) and non-sewage impacted (Rasi Dege) mangrove forest sites along the coast of Dar es Salaam, Tanzania. The Most Probable Number method was used for estimating the total coliform (TC), fecal coliform (FC) and fecal enterococci (ENT) levels. In addition, physicochemical parameters (temperature, pH, salinity and nutrients) were measured. The results for microbial fecal indicators were compared to the World Health Organisation (WHO) and United States Environmental Protection Agency (USEPA) guidelines for marine recreational and shellfish harvesting waters. Fecal bacteria contamination was significantly higher at Mtoni Kijichi …

Characteristics And Dyes Biodegradation Potential Of Crude Lignolytic Enzymes From White-Rot Fungus Crepidotus Variabilis Isolated In Coastal Tanzania, G. Y. S. Gys Mtui

Tanzania Journal of Science

Lignocellulosic enzymes from Crepidotus variabilis collected from mangrove forests of coastal Tanzania were investigated by using standard methods, and their ability to degrade aromatic compounds were elucidated. The fungal crude enzyme filtrates had maximum laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP) activities of 70 U/mL, 16 U/mL and 8, U/mL respectively. The crude enzyme extracts were able to oxidize rhemazol brilliant blue-R (RBB-R) dye, phenol, "-naphthol and pyrogallol. Also, they could remove up to 58% and 92% color from raw textile effluent and aromatic dyes, respectively, after 14 days of incubation at 30ºC and pH 4.5. Desalted and …

Chemical Constituents And Biological Activity Of Three Tanzanian Wild Mushroom Species, L.D. Baraza, C. C. Joseph, M. J. Moshi, M. H. H. Nkunya

Tanzania Journal of Science

The three Tanzanian wild mushroom species Termitomyces letestui, Lactarius edulis and Agaricus sp. aff. arvensis yielded ergosterol, 5,8-peroxyergosterol and ergosta-5,22-dien-3β-ol, and a mixture of ergosterol, ergosta-7,22-dien-3β-ol and ergosta-7-en-3β-ol whose composition was deduced from gas chromatography/mass spectroscopic (GC/MS) analysis of the trimethysilylated mixture. GC/MS analysis of the lipid fraction from T. letestu revealed the presence of linoleic (C18:2), stearic (C18:0), oleic (C18:1), palmitic (C16:0), pentadecanoic (C15:0) and myristic (C14:0) acid. Polar T. letestui and L. edulis fractions yielded α,α,1'trehalose andmannitol. Some of the crude extracts from the three mushroom species showed mild antimicrobial, mosquito larvicidal and cytotoxic activities. The chemical composition …

Effect Of High Pressurized Carbon Dioxide On Escherichia Coli, I. P. Bateebe, O Kibazohi

Tanzania Journal of Science

Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high pressurised carbon dioxide at 15, 25 and 35 bar, and varying exposure times of 20, 40, 60 and 90 minutes at room temperature (27 oC). Microbial inactivation increased with pressure and exposure time. For the first 20 minutes reduction of viable microbial cells was 18%, 30% and 36% at 15, 25 and 35 …

Impact Of Small Scale Gold Mining On Soils Of The Wetland Forests In East Usambara, Tanzania, C. Kweyunga, R. B. M. Rbm Senzota

Tanzania Journal of Science

Soil pits in disturbed and natural wetland forests of East Usambara were excavated and soil profile samples collected and analysed for physical and chemical properties. Their physical and chemical characteristics were found to be sharply different from those of the surrounding hills. Differences included lack of A Horizon, water saturation, presence of very high organic matter, very low pH and hence very poor in basic cations, and low microbial activity. Nutrient recycling, especially nitrogen and phosphorus, tended to shift from mineralization to immobilization. Effects of soil disturbance on both physical and chemical characteristics of the soils were also very vivid. …

Preparation And Nucleophilic Substitution Of The 2,4,6-Triphenylpyridinium Salts, Diazonium Intermediates And N,N-1,2-Benzenedisulfonylimides Of Chiral Amino Acids, S. A. Said

Tanzania Journal of Science

Three methods for preparation of D-amino acids by nucleophilic substitution on derivatives of their L-antipodes have been attempted. Nucleophilic substitution on optically active phenylalanine ethyl ester triphenylpyridinium salt yielded partial inverted azide products. The N,N-disulfonylimide intermediate of the same ester was synthesized in high yield and optical purity, but the substitution reaction on this compound was not achieved. Diazotization of amino acid ammonium chlorides and tosylates in solution of sodium azide in aprotic solvents gave optically active chloro and tosyl compounds instead of the intended azide products. Alternative methods to circumvent the problem of the competing ammonium salt counterions duringdiazotization …

Nebraska Promotes Sorghum And Pearl Millet Food Processing In East Africa, Intsormil

INTSORMIL Impacts and Bulletins

Sorghum and millet are ideal crops for many parts of Africa. However, sorghum and millet’s use as food sources for large urban populations in West Africa is hampered by 1) lack of infrastructure for conveying and demonstrating the food value of sorghum and millet to small business investors, 2) limitations on the supply of high quality grains to processors, 3) lack of small processors, 4) lack of educational resources related to small business development, 5) lack of product development expertise, and 6) lack of knowledge of evidence supporting nutritional claims associated with sorghum and millet consumption.

The Department of Food …

Eleutherodactylus Ridens (Pygmy Rainfrog) Predation, Tobias Eisenberg, Twan Leenders

Biology Faculty Publications

Workers of the large ponerine ant Paraponera clavata typically forage on small to medium-sized arthropods or collect pieces of plants or nectar but have been suspected of predating small vertebrates.

An Age-Structured Resource-Consumer Dynamical Model, Jean M. Tchuenche

Applications and Applied Mathematics: An International Journal (AAM)

Many dynamical systems in population biology in which agents compete for resources may exhibit chaotic fluctuations. This short letter develops Gamarra and Solé's previous work. We briefly review a classical model of population with complex dynamics, and proceed to study the dynamics of an age-structured resource-consumer model, in which the fertility coefficients are density independent. Implicit or first integral solutions of the model are obtained, and conditions for which they are stable given. It is observed that resource availability at any time depends on the number of potential consumers present.

A Survey Of The Cockle A. Antiquata, Chumbe Island, Kelsey Jacobsen, Lisl Esherick

Independent Study Project (ISP) Collection

A survey of the cockle Anadara antiquata’s population was performed on the intertidal zone of Chumbe, a small island located off of Zanzibar, Tanzania. Cockle abundance and size were measured along transects laid parallel to shore at four sites, two sites on the west side and two on the east. The marine and intertidal environments on the western side of the island are protected under Chumbe Island Coral Park (CHICOP), a privately managed Marine Protected Area (MPA). However, small-scale artisanal fisheries including cockle collection by women still occur on the unprotected east side. This study will attempt to evaluate the …