Biology Commons^™

Mitochondria Imaging And Targeted Cancer Treatment, Tinghan Zhao

Dissertations

Mitochondria are essential organelles as the site of respiration in eukaryotic cells and are involved in many crucial functions in cell life. Dysfunction of mitochondrial metabolism and irregular morphology have been frequently found in human cancers. The capability of imaging mitochondria as well as regulating their microenvironment is important both scientifically and clinically. Mitochondria penetrating peptides (MPPs), certain peptides that are composed of cationic and hydrophobic amino acids, are good candidates for mitochondria targeting. Herein, a novel MPP, D-argine-phenylalanine-D-argine-phenylalanine-D-argine-phenylalanine-NH₂ (rFrFrF), is conjugated with a rhodamine-based fluorescent chromophore (TAMRA). The TAMRA-rFrFrF probe exhibits advantageous properties for long-term mitochondria tracking of …

Reintroduction Of The Kihansi Spray Toad Nectophrynoides Asperginis Back To Its Natural Habitat By Using Acclimatizing Cages, Charles A. Msuya, Nassoro Mohamed

Tanzania Journal of Science

The Kihansi Spray Toad (Nectophrynoides asperginis) is considered to be extinct in the wild. Captive breeding populations exist in Bronx and Toledo zoos in USA and in two captive breeding facilities in Tanzania. Efforts to reintroduce the species back to its natural habitat at Kihansi Gorge wetlands have become a long process. Both ex-situ and in-situ experiments have revealed promising outcomes but when the toads are freely (hard) released in the wetlands they disperse widely and detection becomes difficult.  Cages for acclimatising the toads before hard release have been constructed in two of the Kihansi Gorge spray wetlands. Factors such …

Mammals Inventory Of The Kihansi River Gorge In Udzungwa Mountains, Tanzania, Dennis K. Ikanda, Samuel N. Mtoka, Mustafa Hassanali, Anna Mshanga

Tanzania Journal of Science

The Kihansi gorge montane forest in Udzungwa Mountains forms part of the Eastern Arc Mountains (EAM) which contain some of the most biologically diverse and endemic montane ecosystems in all of Africa. The Kihansi river gorge was opened up for hydroelectric development in the late 1990s, attracting hundreds of farming communities whose activities lead to environmental degradation and hence presumed biodiversity loss in the montane forest which is not understood. Using camera traps, an inventory of mammals of the area was conducted for 24 consecutive days. About 14 mammal species were photo captured, indicating diverse assemblage of large and medium …

Morphological Diversity Of Wild Coffee (Coffea Kihansiensis) A Potential Coffee Species For Genetic Improvement, Paul M Kusolwa, Faraja Makwinja, Jackson Nashon, Mayomba Marianna, Amina Kibola

Tanzania Journal of Science

Coffee belongs to the genus Coffea in the Rubiaceae family, and is mostly grown in the tropical and subtropical regions. The Coffea genus comprises 103 species, of which Coffea arabica L. (Arabica coffee) and Coffea canephora P. (Robusta coffee) are the two most important commercial species. C. Arabica is a commercially important high quality coffee with low genetic diversity, while C. canephora is cultivated mostly in the northwestern region of Tanzania. Of recent, a discovered wild coffee (Coffea kihansiensis) in Tanzania may be a genetic resource for improvement of cultivated coffee.  Morphological descriptors from accessions evaluated in different sites at …

Understorey Bird Communities 8 And 18 Years After River Diversion In Kihansi Gorge, Udzungwa Mountains In The Eastern Arc Mountains, Tanzania, Chacha Werema, Charles A. Msuya

Tanzania Journal of Science

On the most south-western slopes of the Udzungwa Mountains in Tanzania lies Kihansi River. The river was diverted underground in 2000 to run electric turbines for electricity generation. Using mist netting, pre-diversion (in 1998 and 1999) and short term post-diversion (in 2001) effects of the river diversion on understorey birds were undertaken before and year after river diversion, respectively. Intermediate and long-term effects of river diversion on understorey birds at the same transects are non-existent. In September 2008 and August and September 2018, using mist nets, birds were surveyed at the same transects  to assess whether or not there have …

Land Use–Land Cover Change And Implication To Biodiversity In Kihansi Catchment, Phillip K. Mwanukuzi

Tanzania Journal of Science

Land cover-land use (LC-LU) change has significant impact on wetland ecosystem. This study examined the impacts of LC-LU change on spray wetland ecology at Kihansi Gorge and implications to conservation of fragile biodiversity. Remote sensing methods were used to asses land cover changes from 1990 to 2015 and to forecast change in 2035. It was revealed that forests decreased from 28,454 to 10,897 ha and woodland from 26,903 to 19,914 ha. In 1990, woody cover dominated with a total cover of 38% of the entire catchment. The cropland that included grassland and bushland with scattered crops has been on the …

Management And Population Status Of Kihansi Spray Toad Nectophrynoides Asperginis In Captive Breeding Facilities In Tanzania, Cuthbert L. Nahonyo, Ezekiel M. Goboro, Richard S. Ugomba, Emmanuel S. Nkombe, Severinus Mutagwaba, Hussein Adam, Juma I. Kimera, Person Kalenga, Wilirk Ngalason

Tanzania Journal of Science

Kihansi spray toad Nectophrynoides asperginis was discovered in 1996 in Kihansi gorge. The toad was declared extinct in the wild in 2009 due to habitat alteration. Before its extinction, 499 individuals were flown to the United States of America zoos in 2000 for captive breeding. In 2010, the University of Dar es Salaam, and in 2011 the Kihansi captive breeding facilities were established in Tanzania. The intention was to breed, and reintroduce the toad back to the natural environment in the gorge. The founder populations for the two facilities were sourced from the USA zoos. This study addresses captive management …

The Dynamics Of Re-Introduced Kihansi Spray Toad Nectophrynoides Asperginis And Other Amphibians In Kihansi Gorge, Udzungwa Mountains, Tanzania, Wilirk Ngalason, Cuthbert L. Nahonyo, Charles A. Msuya

Tanzania Journal of Science

The dynamics of the reintroduced Kihansi spray toad Nectophrynoides asperginis and other amphibian species that occur in the Kihansi gorge, Udzungwa Mountains were studied. The area is a home for the endemic toad that became extinct before individuals bred in captivity were reintroduced. Previous studies on the biology of amphibians conducted in the gorge focused on a few aspects but none has dealt with the dynamics of both the reintroduced Kihansi spray toad (KST) and other amphibians. Information on species richness and the abundance of amphibian species occurring in the gorge have not been dealt with in depth. Time-constrained audio-visual …

Some Histopathological Findings In Dead Kihansi Spray Toads In Captivity, Joshua J Malago

Tanzania Journal of Science

Raising of Kihansi spray toad (KST), Nectophrynoides asperginis, in captivity is associated with disorders that can be fatal. Since diagnosis of these disorders cannot be confirmed grossly, the current study was aimed at exploring histopathological findings in dead KSTs kept under captivity in Tanzania. Dead KSTs were immediately recovered, observed for gross changes, fixed in 10% neutral buffered formalin, processed routinely, and stained sections reviewed for histological changes. Observed infectious agents were strongyloides (25.3%), ciliates (1.7%), lungworms (0.6%), fungi (3.4%) and bacteria (5.1%) or mixed infections (9%) of these agents. Noted histopathological lesions in affected organs included infiltration of inflammatory …

Abundance And Distribution Of Afrosteles Distans An Indicator Of Food Availability For The Kihansi Spray Toad (Nectophrynoides Asperginis) In The Kihansi Gorge, Lulu T Kaaya, Rashid A Tamatamah, Timoth B Suya

Tanzania Journal of Science

Survivorship of the Kihansi Spray Toad in the wild depends on various factors such as environment, habitat, food availability, diseases and predation. This study assessed the abundance of Afrosteles distans Linnavuori 1959 as an indicator of food availability for the Kihansi Spray Toad. Samples were collected from sprinkled (A, B, C, D, E and F) and non-sprinkled (G and H) plots in the upper spray wetland in the Kihansi gorge during the dry period in 2007, 2008, 2015, 2016 and 2018. There was a significantly higher abundance of A. distans in sprinkled than non-sprinkled plots. ANOVA showed significant differences in …

Histopathological Diagnosis Of Diseases Affecting Amphibians Inhabiting Kihansi Gorge, Tanzania, Joshua J Malago

Tanzania Journal of Science

Kihansi gorge is a natural habitat to Kihansi spray toad (KST), Nectophrynoides asperginis. The toad is extinct in its natural habitat partly due to diseases. Efforts to successfully re-introduce it are primed by awareness and mitigation of prevalent diseases at the gorge. This study aimed at exploring the prevalent amphibian diseases at and around Kihansi gorge. A total of 182 individuals from Petropedetes yakusini (n = 60), Nectophrynoides tornieri (n = 60) and Leptopelis uluguruensis (n = 62) species were collected, humanely sacrificed, fixed in formalin, routinely processed, sectioned, stained with haematoxylin and eosin and analysed for diseases by histopathology. …

Metagenomic Analysis Of Dental Calculus In Ancient Egyptian Baboons, Claudio Ottoni, Meriam Guellil, Andrew T. Ozga, Anne C. Stone, Oliver Kersten, Barbara Bramanti, Stephanie Porcier, Wim Van Neer

Biology Faculty Articles

Dental calculus, or mineralized plaque, represents a record of ancient biomolecules and food residues. Recently, ancient metagenomics made it possible to unlock the wealth of microbial and dietary information of dental calculus to reconstruct oral microbiomes and lifestyle of humans from the past. Although most studies have so far focused on ancient humans, dental calculus is known to form in a wide range of animals, potentially informing on how human-animal interactions changed the animals’ oral ecology. Here, we characterise the oral microbiome of six ancient Egyptian baboons held in captivity during the late Pharaonic era (9^th–6^th centuries …

The Need Of A Structured Tilapia Breeding Program In Tanzania To Enhance Aquaculture Production: A Review, Redempta A. Kajungiro, Levinus L. Mapenzi, Christer S. Nyinondi, Anna Norman Haldén, Aviti J. Mmochi, Mwita Chacha, Matern S.P. Mtolera, Hieromin A. Lamtane, Dirk Jan De Koning

Tanzania Journal of Science

Breeding programs are crucial for boosting productivity and increase sustainability of aquaculture. Over years, Tanzania has witnessed fluctuation in its capture fisheries production from 320,900 to 375, 535 and back to 362,595 metric tonnes in the years 2000, 2005 and 2016, respectively (URT 2016). The declining trend in fish production has made fish supply in the country unstable and conversely, increased the demand for fishes to about 730,000 metric tonnes in 2017. However, the local aquaculture production has not increased accordingly. Tanzania is importing fish mainly from Asia to meet its increased demand. In 2017, a total of 2,055,721 kg …

Characterization And Domestication Of Wild Edible Mushrooms From Selected Indigenous Forests In Burundi, Vincent Nteziryayo, Donatha D. Tibuhwa, Prosper Kiyuku, Tatien Masharabu

Tanzania Journal of Science

In Burundi, minimum work has been done to comprehensively identify and commercialize high yielding local mushrooms. The previous studies carried out on mushroom cultivation have focused on exotic strains. This is the first study undertaken on domestication of wild edible mushrooms from Burundi indigenous forests. Nine samples were collected from four protected areas and characterized using phenotypic and molecular markers. Germoplasm isolation through tissue culture techniques, spawn production and cultivation studies were also undertaken. Mushroom samples were identified as Pleurotus citrinopileatus, Lentinus squarrosulus, Hypholoma fasciculare, Laetiporus sulfureus, Macrolepiota dolichaula, Trametes polyzona, Amanita zambiana, Lactarius delicious and Amanita verna. Spawn production …

Antimicrobial Activities Of Endophytic Fungi Secondary Metabolites From Moringa Oleifera (Lam), Zuhura N. Mwanga, Esther F. Mvungi, Donatha D Tibuhwa

Tanzania Journal of Science

This study presents the antimicrobial activities of secondary metabolites of endophytic fungi isolated from a medicinal plant Moringa oleifera growing at the University of Dar es Salaam, Tanzania. Two endophytic fungi were identified, Nigrospora sp. from leaves, and Fusarium sp. from roots and seeds. The disc method was used in testing the antimicrobial activities of the crude extracts of endophytic fungi secondary metabolites against four human pathogens, namely, Bacillus substilis, Staphylococcus aureus, Escherichia coli, and Candida albicans. The results revealed that the crude extracts of endophytes secondary metabolites from leaves showed strong antimicrobial activities against two Gram positive bacteria and …

Climate Change Increasing Threats On Non-Conserved Mangroves Forests Of Micheweni, Zanzibar–Tanzania, Haji M. Hamad, Islam S.S. Mchenga, Mariam I. Hamisi

Tanzania Journal of Science

Overutilization of mangroves has been reported as the factor for mangrove declining across the globe. However, currently, the global climate change has been claimed to pose significant threats to the survival of mangroves. This study analysed the impacts of climatic variability (sea level rise, temperature and precipitation) to the mangroves of Micheweni (non reserve) and Ngezi-Vumawimbi (nature forest reserve). Multi-disciplinary approach was employed to collect information on community perceptions. Secondary time series data of up to 30 years for temperature, rainfall and sea level rise were collected and analysed. Inquiry results on how local communities perceived climate change showed that …

Mixed Mode Device-To-Device Communication Scheme For Congestion Reduction And Channel Usage Optimization In 5g Cellular Networks, Chiza M. Christophe, Omar F. Hamad, Libe V. Massawe, Abdi T. Abdalla

Tanzania Journal of Science

Device-to-Device (D2D) communication schemes have gained more attention in cellular networks particularly in normalization process of the upcoming 5G networks. They have been investigated in core network offloading, congestion reduction and channel usage optimization.  The two last cases are among the major constraints in current cellular networks and are the main concerns of this paper. The paper presents a mixed mode D2D communication scheme to decentralize data collection between devices and the base station in order to reduce the number of direct connections at the base station of ultra-dense cells characterized by different levels of channel utilizations or target data …

Assessment Of Tree Species Richness, Diversity, Population Structure And Natural Regeneration In Nongeni Forest Reserve In Morogoro Region, Tanzania, David Sylvester Kacholi

Tanzania Journal of Science

This study examined tree species richness, diversity, population structure and regeneration in Nongeni forest reserve, Morogoro, Tanzania. The study deployed plot sampling technique whereby a total of 20 plots of 0.05 ha each were randomly established in the forest. All species and individuals encountered in each plot were counted, identified and DBH measured. A total of 751 individuals/ha representing 24 species belonging to 11 families were recorded. Family Fabaceae was dominant with 9 species. The Shannon-Wiener, Margalef, Simpson’s and Pielou J index were calculated as 2.667, 3.474, 10.58 and 0.839, respectively. The Diplorhynchus condylocarpon (52.18) was the dominant species in …

An Investigation Of The Potentials Of 2-[(2-Hydroxyphenyl) Methylidene] Hydrazine-1-Carbothioamide And Its Mn(Ii) And Zn(Ii) Complexes As Antimicrobial Agents, Umar Sani, Musbahu Yahaya, Dailami S. Adam

Tanzania Journal of Science

Antibiotic resistance as a result of misuse, overuse or abuse of drugs is an issue of serious concern world over. The quest for more active and robust antimicrobial agents remains a scientific challenge and requires multimillion-dollar investment in the area of drug design and development. Here in, we report the synthesis and characterisation of a tridentate thiosemicarbazone (2-[(2-hydroxyphenyl)methylidene]hydrazine-1-carbothioamide) (HL) from salicylaldehyde and thiosemicarbazide. Its complexes with Mn(II) and Zn(II) were prepared following similar technique and characterised by melting point, FT-IR, UV –visible spectrophotometry, and elemental analysis. The Mn(II) complex showed paramagnetism with a magnetic moment value of 5.80 BM while …

Generation Of Highly Ordered 3d Vivid Monochromatic Coloured Photonic Crystal Films Using Evaporative Induced Technique, Ikhazuagbe H. Ifijen, Esther U. Ikhuoria

Tanzania Journal of Science

Structural coloured crystal films have attracted immense attention because of numerous applications like optical sensing, anti-counterfeiting and photonic fabrics.  Herein, we successfully generated highly periodic three-dimensional (3D) monochromatic structural crystal films with brown, turquoise, blue and yellow colourations from as-synthesized poly(styrene-methyl methacrylate-acrylic acid) or P(St-MMA-AA) colloidal latex via the evaporative induced self-assembly technique. The colours were controlled through the modulation of their crystal lattice by varying their microspheres diameter from 180 nm, 120 nm, and 260 nm to 150 nm. Scanning electron microscope and atomic force microscope (SEM/AFM) analyses showed that the photonic crystal particles readily assembled into an impeccable …

Potential Distribution Of Six North American Higher-Attine Fungus-Farming Ant (Hymenoptera: Formicidae) Species, Sarah F. Senula, Joseph T. Scavetta, Joshua A. Banta, Ulrich G. Mueller, Jon N. Seal, Katrin Kellner

Biology Faculty Publications and Presentations

Ants are among the most successful insects in Earth’s evolutionary history. However, there is a lack of knowledge regarding range-limiting factors that may influence their distribution. The goal of this study was to describe the environmental factors (climate and soil types) that likely impact the ranges of five out of the eight most abundant Trachymyrmex species and the most abundant Mycetomoellerius species in the United States. Important environmental factors may allow us to better understand each species’ evolutionary history. We generated habitat suitability maps using MaxEnt for each species and identified associated most important environmental variables. We quantified niche overlap …

Defects In Mating Behavior And Tail Morphology Are The Primary Cause Of Sterility In Caenorhabditis Elegans Males At High Temperature, Emily M. Nett, Nicholas B. Sepulveda, Lisa N. Petrella

Biological Sciences Faculty Research and Publications

Reproduction is a fundamental imperative of all forms of life. For all the advantages sexual reproduction confers, it has a deeply conserved flaw: it is temperature sensitive. As temperatures rise, fertility decreases. Across species, male fertility is particularly sensitive to elevated temperature. Previously, we have shown in the model nematode Caenorhabditis elegans that all males are fertile at 20°C, but almost all males have lost fertility at 27°C. Male fertility is dependent on the production of functional sperm, successful mating and transfer of sperm, and successful fertilization post-mating. To determine how male fertility is impacted by elevated temperature, we analyzed …

Seed‐To‐Seedling Transitions Exhibit Distance‐Dependent Mortality But No Strong Spacing Effects In A Neotropical Forest, Philippe Marchand, Liza S. Comita, S. Joseph Wright, Richard Condit, Stephen P. Hubbell, Noelle G. Beckman

Biology Faculty Publications

Patterns of seed dispersal and seed mortality influence the spatial structure of plant communities and the local coexistence of competing species. Most seeds are dispersed in proximity to the parent tree, where mortality is also expected to be the highest, because of competition with siblings or the attraction of natural enemies. Whereas distance‐dependent mortality in the seed‐to‐seedling transition was often observed in tropical forests, few studies have attempted to estimate the shape of the survival‐distance curves, which determines whether the peak of seedling establishment occurs away from the parent tree (Janzen–Connell pattern) or if the peak attenuates but remains at …

Assessing The Blood Meal Hosts Of Culex Quinquefasciatus And Aedes Taeniorhynchus In Isla Santa Cruz, Galápagos, Samoa Asigau, Sawsan Salah, Patricia Parker

Biology Department Faculty Works

No abstract provided.

A Self-Marker-Like Protein Governs Hemocyte Allorecognition In Halocynthia Roretzi, Masaki Ema, Taizo Okada, Miki Takahashi, Masato Uchiyama, Hideo Kubo, Hideaki Moriyama, Hitoshi Miyakawa, Midori Matsumoto

School of Biological Sciences: Faculty Publications

Background: Self-incompatibility, fusion/non-fusion reactions, and contact reactions (CRs) have all been identified as allorecognition phenomena in ascidians. CR is a reaction characteristic of the hemocytes of Halocynthia roretzi, whereby they release phenol oxidase (PO) upon contact with non-self hemocytes. Thus, these cells may represent a primitive form of the vertebrate immune system. In the present study, we focused on the CR of H. roretzi hemocytes and sought to identify self-marker proteins that distinguish between self and non-self cells.

Results: We initially generated a CR-inducing monoclonal antibody against the complete hemocyte membraneprotein complement (mAb11B16B10). This antibody was identified based on the …

A Landscape On The Threshold Of Change: Patterns Of Soil Microbial Ecology Along Dynamic Geomorphic And Hydrologic Features In A Polar Desert, Kelli L. Feeser, David James Van Horn, Heather N. Buelow, Daniel R. Colman, Theresa A. Mchugh, Jordan G. Okie, Egbert Schwartz, Cristina D. Takacs-Vesbach, Becky A. Ball, Andrew G. Fountain, Michael N. Gooseff, Joseph S. Levy, Maciej K. Obryk

Biology ETDs

The McMurdo Dry Valleys (MDV) of Antarctica are on the threshold of widespread landscape scale change due to increasing temperature and solar radiation and altered hydrology: buried ice is melting, the soil active layer is thickening, thermokarst features are developing along streams, water tracks are expanding, and lake levels are rising. These changes will impact the microbial communities found in each of the affected habitats. The purpose of this work is to first, understand the spatial distribution of soil bacteria in the MDV, specifically investigating the scale-dependent effects of environmental heterogeneity, and second, to perform surveys and coupled experiments to …

Effects Of Temperature On Enzyme Activity Of Aquatic Litter-Associated Fungi, Nicholas Bautz

Honors Theses

The decomposition of leaf litter in aquatic ecosystems is carried out mostly by microorganisms, including bacteria and fungi. Fungi, known as aquatic hyphomycetes, dominate microbial communities in the decomposition of leaf litter. These fungi produce extracellular enzymes that aid in the sequestration of carbon and nutrients and lead to the breakdown of complex plant polymers. We evaluated the effects of temperature on extracellular enzyme activity within the framework of the Metabolic Theory of Ecology (MTE). The activity of β-1,4-glucosidase and β-1,4-xylosidase was estimated fluorometrically using artificial substrate analogs. Phenol oxidase activity was estimated spectrophotometrically from oxidation of L-DOPA (L-3,4-dihydroxyphenylalanine). We …

Early Child Development Amid The Pandemic, Zain Saeed Siddiqui

MSJ Capstone Projects

I would like to bring to notice the importance of early child development because the early years are crucial for the development especially the skills that are going to help children succeed in life. Basically, I would like to focus on the natural development of the human being from birth to maturity, enabling children to become the transforming elements of society, leading to a harmonious and peaceful world.

Emotional well-being and social competence provide a strong foundation for emerging cognitive abilities, and together they are the bricks and mortar that comprise the foundation of human development.

Generally, development happens in …

Investigating Biological Mechanisms Of Radiation Resistance In Advanced Stage Cervical Cancer, Fiona Ruiz

Arts & Sciences Graduate Student Theses and Dissertations

The current standard of care treatment for locally advanced cervical cancer is curative intent pelvic radiation with concurrently administered platinum chemotherapy (CRT). This treatment strategy is effective for many patients, but 33-50% of patients treated with CRT develop disease recurrence. Metastatic and recurrent cervical cancer is an incurable condition, and many of the currently available treatments are associated with significant morbidity and mortality. Identifying these patients upfront is a challenge that clinicians face when developing treatment strategies. Previous studies used to catalog the genomic and transcriptomic landscape of cervical cancer lacked high quality corresponding clinical follow up data for patients, …

A Noncanonical Function Of The Telomerase Rna Component In Human Embryonic Stem Cells, Kirsten Ann Brenner

Arts & Sciences Graduate Student Theses and Dissertations

Telomeres are stretches of TTAGGG nucleotide repeats located at the ends of linear chromosomes that shorten with progressive cell division and prevent genomic instability at the cost of limiting a cell’s capacity to proliferate. This limitation can be overcome by telomerase, a ribonucleoprotein complex that elongates telomeres via reverse-transcription of the template telomerase RNA component (TERC). Recent studies have reported potential functions of TERC outside of its role in telomere maintenance. These noncanonical functions of TERC are however poorly defined, and the molecular mechanisms and biological relevance behind such functions remain elusive. Here, we generated conditional TERC knock-out human embryonic …