An Introduction to Digital Signal Processing

An Introduction to Digital Signal Processing aims at undergraduate students who have basic knowledge in C programming, Circuit Theory, Systems and Simulations, and Spectral Analysis. The book is focused on basic concepts of digital signal processing, MATLAB simulation and implementation on selected DSP hardware in which the candidate is introduced to the basic concepts first before embarking to the practical part which comes in the later chapters. Initially Digital Signal Processing evolved as a postgraduate course which slowly filtered into the undergraduate curriculum as a simplified version of the latter. The goal was to study DSP concepts and to provide a foundation for further research where new and more efficient concepts and algorithms can be developed. Though this was very useful it did not arm the student with all the necessary tools that many industries using DSP technology would require to develop applications. This book is an attempt to bridge the gap. It is focused on basic concepts of digital signal processing, MATLAB simulation and implementation on selected DSP hardware. The objective is to win the student to use a variety of development tools to develop applications. Contents• Introduction to Digital Signal processing.• The transform domain analysis: the Discrete-Time Fourier Transform• The transform domain analysis: the Discrete Fourier Transform• The transform domain analysis: the z-transform• Review of Analogue Filter• Digital filter design.• Digital Signal Processing Implementation Issues• Digital Signal Processing Hardware and Software• Examples of DSK Filter Implementatio

An Introduction to Digital Signal Processing

An Introduction to Digital Signal Processing aims at undergraduate students who have basic knowledge in C programming, Circuit Theory, Systems and Simulations, and Spectral Analysis. The book is focused on basic concepts of digital signal processing, MATLAB simulation and implementation on selected DSP hardware in which the candidate is introduced to the basic concepts first before embarking to the practical part which comes in the later chapters. Initially Digital Signal Processing evolved as a postgraduate course which slowly filtered into the undergraduate curriculum as a simplified version of the latter. The goal was to study DSP concepts and to provide a foundation for further research where new and more efficient concepts and algorithms can be developed. Though this was very useful it did not arm the student with all the necessary tools that many industries using DSP technology would require to develop applications. This book is an attempt to bridge the gap. It is focused on basic concepts of digital signal processing, MATLAB simulation and implementation on selected DSP hardware. The objective is to win the student to use a variety of development tools to develop applications. Contents• Introduction to Digital Signal processing.• The transform domain analysis: the Discrete-Time Fourier Transform• The transform domain analysis: the Discrete Fourier Transform• The transform domain analysis: the z-transform• Review of Analogue Filter• Digital filter design.• Digital Signal Processing Implementation Issues• Digital Signal Processing Hardware and Software• Examples of DSK Filter Implementatio

Control of lethal browning by using ascorbic acid on shoot tip cultures of a local Musa spp. (Banana) cv. Mzuzu in Tanzania

The use of ascorbic acid during explants preparation and the effect of different concentrations of ascorbic acid in controlling lethal browning and survival of the explants in local banana cv. Mzuzu banana were investigated. The explants were taken from young suckers. The shoot tips were cultured on Murashige and Skoog’s media supplemented with 5 mg/l of benzylaminopurine (BAP) and different concentrations of ascorbic acid (0, 50, 100 and 200 mg/l). Completely randomized design was used in this study. The results indicate that the use of ascorbic acid as an antioxidant during explants preparation significantly reduced the extent of lethal browning and survival of the explants followed by 100 mg/l of ascorbic acid applied directly into the media.Keywords: Micro propagation, surface sterilization, survival of explants, tissue cultureAfrican Journal of Biotechnology, Vol 13(16), 1721-172

Agro-morphological Characterization of the Wild Rice (Oryza longistaminata) Populations From Selected Areas of Tanzania

The study assessed the variations in ten agro-morphological characters among and within the wild rice (O. longistaminata) populations from four selected areas, namely Bagamoyo, Kibaha, Kilombero and Mbarali in Tanzania. The study was carried out through measurement of ten quantitative agro-morphological characters, based on morphological descriptors for wild and cultivated rice species developed by Bioversity International and International Rice Research Institute (IRRI). Measurement of morphological characters of O. longistaminata plants was done soon after heading. One-way Analysis of Variance (ANOVA) was used to compare the variations in quantitative characters between O. longistaminata populations from the four study areas. The results showed existence of high genetic variations in the study areas, both within populations and among populations. In addition, the results showed significant differences between populations for all quantitative agro-morphological characters, except grain length. Moreover, some agro-morphological characters showed positive correlations to each other. The dendogram generated from the agro-morphological data grouped the O. longistaminata from the four study areas into four groups irrespective of their geographic origins, implying that there was gene flow between populations. Generally, the four O. longistaminata populations assessed exhibited a wide range of variations in morphological characters, both within the population and among populations.Keywords: Morphological character; Oryza longistaminata; Quantitative character; Wild rice

Assessment of Genetic Diversity of the Wild Rice (Oryza longistaminata) Populations in Tanzania Using Microsatellite Markers

The genetic diversity of 132 samples of the perennial wild rice (Oryza longistaminata) populations from selected districts (Bagamoyo, Kibaha, Kilombero and Mbarali) in Tanzania was evaluated using twenty eight microsatellite markers. Genomic DNA was extracted using standard protocols. Polymerase Chain Reaction (PCR) was carried out in a total reaction volume of 10 μL, using Touchdown protocol. It was found that all 28 microsatellite markers generated polymorphic patterns, with average Polymorphic Information Content (PIC) value of 0.631. Moreover, a total of 243 alleles were detected by the 28 markers, with average of 8.68 alleles per marker. The percentages of genetic variations among and within populations were 10% and 90%, respectively, implying that there was more gene flow among populations than within populations. Furthermore, the O. longistaminata population from Kilombero had highest genetic diversity followed by population from Mbarali, while the lowest genetic diversity was recorded in the population from Kibaha. Generally the populations from Kilombero, Mbarali and Bagamoyo were found to have relatively high genetic diversity, hence have potential to be used in rice breeding. In situ conservation of this species is recommended, and it can be achieved by conserving all areas which harbour populations with high levels of genetic diversity. Keywords: Genetic diversity; Microsatellites; SSR Markers; Oryza longistaminata; Wild rice

Assessment of Soil Physico-Chemical Properties in Selected Natural Habitats of The Wild Rice (Oryza Longistaminata) and their Effects on the Species Morphological Characters

The aim of this study was to assess variation in some soil physical and chemical properties among four selected natural habitats of the wild rice species (Oryza longistaminata) in Tanzania, and their effects on the species morphological characters. Oryza longistaminata is a perennial wild rice species with agronomically important genes, including genes for tolerance to biotic and abiotic stresses that can be used in rice breeding. In Tanzania O. longistaminata grows sympatrically with the cultivated rice (Oryza sativa) in most rice cultivating areas. The selected natural habitats assessed were located in four districts, namely Bagamoyo, Kibaha, Kilombero and Mbarali. Soil samples were collected at the depth of 0 - 20 cm from the four districts and analysed in the laboratory for soil physico-chemical properties using standard protocols. The species morphological characters were assessed based on the morphological descriptors for wild and cultivated rice species developed by Bioversity International and International Rice Research Institute. One way ANOVA was used to determine the extent of variation in soil physico-chemical properties (parameters) among the four natural habitats of O. longistaminata. Canonical Correspondence Analysis (CCA) was used to determine the effects of assessed soil parameters on the morphological characters of O. longistaminata in the study areas. The study revealed variation in soil physico-chemical properties among the districts. Statistically there were significant differences among the habitats (districts) for most of soil physico-chemical properties investigated. In addition, the assessed soil physico-chemical properties were found to influence variation in morphological characters among O. longistaminata populations from different habitats

Delivering new sorghum and finger millet innovations for food security and improving livelihoods in Eastern Africa

ILRI works with partners worldwide to help poor people keep their farm animals alive and productive, increase and sustain their livestock and farm productivity, and find profitable markets for their animal products. ILRI’s headquarters are in Nairobi, Kenya; we have a principal campus in Addis Ababa, Ethiopia, and 14 offices in other regions of Africa and Asia. ILRI is part of the Consultative Group on International Agricultural Research (www.cgiar.org), which works to reduce hunger, poverty and environmental degradation in developing countries by generating and sharing relevant agricultural knowledge, technologies and policies

In vitro regeneration of selected commercial Tanzanian open pollinated maize varieties

Four Tanzanian open pollinated maize varieties namely; Kito, Situka M-1, Staha and TMV-1 were regenerated in vitro using immature zygotic embryos as ex-plants. Callus induction was achieved using Murashige and Skoog (MS) basal medium supplemented with 1, 1.5, 2 or 2.5 mg/l of 2, 4-D. Callus induction was significantly affected by the genotype of the varieties. Among the varieties tested, Kito, Situka M-1 and Staha had significantly higher callus induction frequency of 84.4, 92.7 and 88.7%, respectively compared to TMV-1 (43.3%). Embryogenic callus induction percentage was significantly influenced by the genotype, 2, 4-D concentrations and their interaction effect implying differential response of the genotypes to 2, 4-D concentrations. Among the genotypes tested, Kito gave significantly (p<0.05) the highest embryogenic callus frequency of 69.5%. Great variations were observed among the genotypes with regard to regeneration frequencies. Staha was comparatively the most regenerable variety with RF of 32.6% than even Kito which had the highest callus induction and embryogenic callus formation. MS medium amended with 1 mg/l 2, 4-D was observed to be the optimum formulation for the induction of embryogenic calli for genotypes tested in this study. Using this regeneration system Situka M-1, Staha and TMV-1 can now be improved against various production constraints through genetic engineering.Key words: 2, 4-dichlorophexyacetic acid, embryogenic callus, immature zygotic embryos, regeneration frequency, somatic embryos, Tanzanian open pollinated maize

Diversity of Sorghum (Sorghum bicolor L. Moench) Germplasm from Tanzania

Sorghum (Sorghum bicolor L. Moench) is an important cereal crop cultivated in varied agro-ecological zones of Tanzania ranging from the southern highlands to coastal lowlands. Different cultivars and varieties of sorghum are needed for cultivation in such varied zones. Phenotypic properties of Tanzanian sorghums are not well-studied. Objective of this study was to phenotype some sorghum germplasm from Tanzania using morphological markers to establish their diversity for future use in breeding programs. Ninety-eight sorghum genotypes were evaluated at Bumala and Amagoro in Western Kenya during 2009 and 2010 seasons in a randomized complete block design. The International Plant Genetic Resource Centre descriptors of 1993 were used for data collection. Accession MCSR T29 was the earliest which took only 64 days while MCSR T80 was the latest taking 86 days to attain 50% flowering compared to the overall mean of 71 days. The MCSR T71 was the best yielder (114.6 g/ panicle) and MCSR T10 was the lowest (10.3 g/panicle) compared to overall mean of 92.4g/panicle. About 60% of the sorghums had brown and only 2.2% had black grains. MCSR T90 had bold grains with 1000 seed weight of 55.2g. Leaves per plant ranged from 7 in MCSR T69 to 17 in MCSR T25. Plant height ranged from 72.8 cm in MCSR T53 to 434.6 cm in MCSR T80. This study showed that, Tanzanian sorghums are diverse therefore could be used in future breeding programs for developing multipurpose and adapted cultivars. Keywords: Cultivars, Diversity, Phenotype, Varieties, SorghumSorghum (Sorghum bicolor L. Moench) is an important cereal crop cultivated in varied agro-ecological zones of Tanzania ranging from the southern highlands to coastal lowlands. Different cultivars and varieties of sorghum are needed for cultivation in such varied zones. Phenotypic properties of Tanzanian sorghums are not well-studied. Objective of this study was to phenotype some sorghum germplasm from Tanzania using morphological markers to establish their diversity for future use in breeding programs. Ninety-eight sorghum genotypes were evaluated at Bumala and Amagoro in Western Kenya during 2009 and 2010 seasons in a randomized complete block design. The International Plant Genetic Resource Centre descriptors of 1993 were used for data collection. Accession MCSR T29 was the earliest which took only 64 days while MCSR T80 was the latest taking 86 days to attain 50% flowering compared to the overall mean of 71 days. The MCSR T71 was the best yielder (114.6 g/ panicle) and MCSR T10 was the lowest (10.3 g/panicle) compared to overall mean of 92.4g/panicle. About 60% of the sorghums had brown and only 2.2% had black grains. MCSR T90 had bold grains with 1000 seed weight of 55.2g. Leaves per plant ranged from 7 in MCSR T69 to 17 in MCSR T25. Plant height ranged from 72.8 cm in MCSR T53 to 434.6 cm in MCSR T80. This study showed that, Tanzanian sorghums are diverse therefore could be used in future breeding programs for developing multipurpose and adapted cultivars. Keywords: Cultivars, Diversity, Phenotype, Varieties, Sorghu

Tolerance to aluminium toxicity in Tanzanian sorghum genotypes

Aluminium (Al) toxicity is a major abiotic constraint on grain sorghum (Sorghum bicolor L. Moench) production on acid soils in East Africa. Aluminium in acidic soil inhibits water and mineral uptake from and consequently, reduces plant vigour and yield. A study was done to determine genetic diversity of Tanzania's sorghum for response to Al toxicity. Five day old seedlings of 98 sorghum genotypes were subjected to 0, 148 or 222.25 moles of Al3+ supplied as Al2 (SO4)3.16H2O in Hoagland's nutrient solution. Seedlings were raised in a growth chamber for five days, after which root lengths were recorded. Net root growth was used to discriminate the germplasm into phenotypic groups. The genotype MCSR T33 exhibited highest net root length and was classified as tolerant. Wahi, MCSR T69 and MCSR T11 were moderately tolerant, while the rest were susceptible.La toxicit\ue9 aluminique est une contrainte majeur \ue0 la production du sorhgo (Sorghum bicolor L. Moench) sur les sols acides en Afrique de l'est. L'aluminium (Al) des sols acides inhibe l'assimilation d'eau et de min\ue9raux du sol, et r\ue9duit par cons\ue9quent la vigueur des plantes et le rendement.Une \ue9tude \ue9tait faite pour d\ue9terminer la diversit\ue9 g\ue9n\ue9tique du sorgho de la Tanzanie en r\ue9ponse \ue0 la toxicit\ue9 aluminique. Les plants ag\ue9s de 5 jours issus de 98 g\ue9notypes de sorgho \ue9taient soumis \ue0 0, 148 ou 222.25 moles de Al3+ fournis sous forme de Al2 (SO4)3.16H2O dans une solution de nutriment de Hoagland. Les plantules \ue9taient plant\ue9es dans la chambre de croissance pendant 5 jours apr\ue8s lesquels la longueur des racines \ue9tait mesur\ue9e. La croissance nette des racines \ue9tait utilis\ue9e pour s\ue9parer les racines en groupes ph\ue9notypiques. Le g\ue9notype MCSR T33 avait exhib\ue9 une longueur nette plus \ue9lev\ue9e des racines et \ue9tait classifi\ue9 comme tol\ue9rant. Wahi, MCSR T69 et MCSR T11 \ue9taient mod\ue9r\ue9ment tol\ue9rant, alors que les restes \ue9taient susceptibles