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Spectroscopic studies of titanium ions in PbO–Sb2O3–As2O3 glass system
(Elsevier, 2004) Laxmikanth, C.; Veeraiah, N.; Raghavaiah, B, V.
PbO–Sb2O3–As2O3 glasses containing small concentrations of TiO2 ranging from 0 to 0.5 mol% were prepared. A number of studies viz. differential scanning calorimetry, infrared spectra, optical absorption, ESR spectra and magnetic susceptibility have been carried out as a function of titanium ion concentration. The interesting changes observed in these properties are discussed in the light of different oxidation states of titanium ions.
Prenylindoles from Tanzanian Monodora and Isolona Species
(Taylor & Francis, 2004) Nkunya, Mayunga H.H.; Makangara, John J.; Jonker, Stephan A.
6-(3-Methyl-but-2-enyl)-1,3-dihydro-indol-2-one, annonidine F [3-[6-(3-methyl-but-2-enyl)-1H-indolyl]-6-(3-methyl-but-2-enyl)-1H-indole], 1H-indole-5-carbaldehyde, 6-(3-methyl-2-butenyl)-1H-indole, 6-(3-methylbuta-1,3-dienyl)-1H-indole, 6-(4-oxo-but-2-enyl)-1H-indole and 3-geranylindole were isolated from Monodora angolensis (Annonaceae) while 3-(1,1-dimethyl-but-2-enyl)-5-(3-methyl-but-2-enyl)-1H-indole (caulidine A), 4-[3-(1,1-dimethyl-but-2-enyl)-1H-indol-5-yl]-but-3-en-2-one (caulidine B), 5-(3-methyl-2-butenyl)-1H-indole and 5-(3-methylbuta-1,3-dienyl)-1H-indole were obtained from Isolona cauliflora (Annonaceae); structural determination by spectroscopic analysis. Some of the prenylindoles had antifungal and antimalarial activities.
Benefits and costs of illegal grazing and hunting in the Serengeti ecosystem
(Cambridge University Press, 2005) Nyahongo, J. W; East, M. L.; Mturi, F. A.; Hofer, H.
Two forms of natural resource use (meat hunting and livestock grazing) were investigated at three sites in the western region of the Serengeti ecosystem, Tanzania. Statutory management of natural resources in this region was designated as National Park, Game Reserve or village council. A quasi-experimental design examined factors likely to alter the cost and benefit of illegal use by ranking areas within sites in relation to these factors. Factors likely to alter costs were the chance of arrest, determined by the presence or absence of guard posts, and the distance travelled to the site of exploitation. As all sites experienced large fluctuations in the density of migratory herbivores, it was assumed that the benefit acquired from hunting increased with wild herbivore density. Marked seasonal changes in precipitation were considered likely to alter the value of forage and water to livestock owners. Hunting effort (density of snares) increased as the density of wild herbivores increased. The distribution of hunting effort across sites was more consistent with the prediction that high travel costs were more likely to curtail hunting than a high potential cost of arrest. Unlike hunters, livestock owners mostly avoided the use of resources in protected areas probably because of the high potential cost of arrest and confiscation of stock. Natural resources within protected areas were exploited when benefits outweighed likely costs.
The nature of hunting around the western corridor of Serengeti National Park, Tanzania
(Springer Nature, 2005) Kaltenborn, B. P.; Nyahongo, J. W.; Tingstad, K. M.
In many parts of Africa, illegal hunting is considered the most pressing issue in protected areas. Poaching has remained a persistent problem through the 50 year long history of Serengeti National Park. Around 2 million people live along the borders of the park. Poverty is widespread, and the population is increasing rapidly. In this paper we examine the local perceptions of importance and reasons for hunting, gender differences and opinions about mitigating measures among villagers around Serengeti’s Western Corridor. The data were collected through interviewing 590 persons in eight villages close to the borders of the park. Hunting is driven by the need to not only increase food supply and cash income, but also fulfil cultural and social needs. We also identified a proactive attitude in the rural communities towards reducing illegal hunting and more constructive relationships with the management authorities of the national park. The role of hunting in community life extends beyond the immediate poverty issue, and should be seen as an element in the larger development agenda of rural Tanzania and the quest for models for sustainable wildlife management.
Animal preferences and acceptability of wildlife management actions around Serengeti National Park, Tanzania
(Springer Nature, 2006) Kaltenborn, B. P.; Bjerke, T.; Nyahongo, J. W.; Williams, D. R.
Wildlife management policies are often based on expert perceptions of the ecological importance of certain species and poorly informed perceptions of how public attitudes toward management are formed. Little is known about why preferences vary greatly and how this affects support for management actions. This paper explores preferences for a range of wildlife species among a sample of the rural population adjacent to Serengeti National Park in Tanzania. We also examine the degree of acceptance for alternative management interventions when potentially dangerous animals pose different levels of problems to human beings, and the extent to which these attitudes are related to species preferences. Gender has a significant effect on species preferences. Men like most species better than women. Age has no significant effect, but level of education affects preference level for some species. Species preferences have a positive effect on support for management intervention when dangerous animals cause small or moderate problems to humans, i.e. there is a higher degree of acceptance of problems caused by animals that are well liked. In situations where human life is threatened, species preferences have no effect on preferred management actions. Appreciation of animals is a combination of functional, consumptive and cultural dimensions, and there is no simple link between species preferences and attitudes toward management actions. The local context and concrete experience with wildlife encounters is more important for shaping normative beliefs like attitudes towards management actions than global wildlife attitudes.
Living with problem animals—Self-reported fear of potentially dangerous species in the Serengeti Region, Tanzania
(Taylor & Francis, 2006) Kaltenborn, Bj⊘rn P.; Bjerke, Tore; Nyahongo, Julius
We examined the relationship between self-reported fear of large carnivores and the demographic characteristics of villagers living in a rural district adjacent to Serengeti National Park in Tanzania. Data were obtained from 593 respondents living in 8 villages. The intensity of verbally expressed attitudes was heavily dependent on whether the attitude object was of a general or a specific category. Level of self-reported fear was much higher for specific species of large carnivores than for broad verbal categories like concern over safety due to carnivores in general. Women were more afraid than men. The elderly expressed lower fear than other age groups, but only in response to the general category question. Level of fear was positively correlated with educational level. For almost all questions, villagers living further away from the national park expressed more fear than villagers living closer to the park. Fear can influence attitudes toward wildlife. Understanding whether encounters with wildlife are experienced as positive or negative can help in forming management strategies that are effective in reducing human–wildlife conflicts.
Factors and ecological impacts of wildlife habitat destruction in the Serengeti ecosystem in northern Tanzania
(AJEAM-RAGEE., 2006) Kideghesho, Jafari R.; Nyahongo, Julius W.; Hassan, Shombe N.; Tarimo, Thadeo C.; Mbije, Nsajigwa E.
Despite the considerable worldwide efforts to establish the wildlife protected areas - a strategy construed as the most feasible in maintaining the high quality habitats for healthy wildlife populations - destruction of wildlife habitats has remained the leading threat to biodiversity. This destruction, taking different forms (i.e. degradation, fragmentation or outright loss) is a function of the growing human activities - prompted mainly by such factors as poverty, demographic factors, land tenure systems, inadequate conservation status, development policies and economic incentives. This paper reviews these contributing factors and presents the associated ecological impacts – manifested by a decline of wildlife populations and local extinction of species. Provision of adequate conservation status to critical wildlife habitats, addressing the problem of human population growth, adoption of poverty reduction strategies that are conservation-friendly and discouraging the destructive development policies are recommended as the measures to mitigate the problem. Other measures entail genuine involvement of the local communities in conservation, provision of adequate economic incentives, relevant research and participatory land use planning. In conclusion, the paper argues that, given the nature of the problem, if a lasting solution is to be realized, habitat loss should be viewed as a multisectoral rather than a single sectoral issue. Therefore different stakeholders should play an active role in halting and pre-empting the problem. We propose criteria for selection of the relevant stakeholders.
Livestock loss caused by predators outside the Serengeti National Park, Tanzania
(Elsevier Ltd, 2007) Holmern, Tomas; Nyahongo, Julius; Røskaft, Eivin
Human–carnivore conflict is a serious management issue often causing opposition towards conservation efforts. In a survey of 481 households in seven different villages outside the Serengeti National Park in Tanzania, 67.4% of respondents owned livestock and 27.4% of all the households surveyed reported losses of a total of 4.5% of their livestock to wild predators over 12 months. This loss equated to an average annual financial loss of 19.2% (US $26.8) of their cash income. Livestock depredation was reported to be caused most often by spotted hyena (Crocuta crocuta) (97.7%), leopard (Panthera pardus) (1.6%), baboon (Papio cynocephalus) (0.4%), lion (Panthera leo) (0.1%) and lastly black-backed jackal (Canis mesomelas) (0.1%). Total reported losses during 2003 amounted to US $12,846 of which spotted hyena kills were reported to account for 98.2%. The mean annual livestock loss per household (of those that reported loss) was 5.3 head of stock, which represents more than two-thirds of the local average annual cash income. Depredation by large felids occurred only in a narrow zone along the protected area (<3 km), whereas spotted hyenas killed livestock even in households located far away (>30 km). Tolerance of livestock depredation among the respondents was low. Logistic regression models indicated that education improved tolerance, while for livestock owners higher depredation rates was linked to approval of lethal retaliation and effective protection measures was associated with a reduced desire of retaliation. We recommend that further research should identify the precise causes of livestock loss and which protection measures that can reduce depredation.
Solute generation and CO2 consumption during silicate weathering under subtropical, humid climate, northern Okinawa Island, Japan
(Elsevier, 2007) Vuai, S. A. H.; Tokuyama, A.
The chemical characteristics of freshwaters draining the silicate rocks in the northern part of Okinawa Island were studied to understand solute generation processes, and to determine rates of chemical weathering and CO2 consumption. It was observed that the water chemistry is highly influenced by marine aerosols, contributing more than 60% of total solute. Significant positive correlations observed for chloride versus dissolved silica and chloride versus bicarbonate suggest a strong influence of evapotranspiration on the seasonality of solute concentration. It was also found that chemical weathering has been highly advanced in which the dominant kaolinite minerals are being gibbsitized. Carbonic acid was found to be the major chemical weathering agent, releasing greater than 80% of weathering-derived dissolved cations and silica while the remaining portion was attributed to weathering by sulfuric acid generated via oxidation of pyrite contained in the rocks. The flux of basic cations, weathering-derived silica and CO2 consumption were relatively high due to favourable climatic condition, topography and high rate of mechanical erosion. Silicate weathering rates for basic cations were estimated to be 6.7–9.7 ton km− 2 y− 1. Carbon dioxide consumed by silicate weathering was 334–471 kmol km− 2 y− 1 which was slightly higher than that consumed by carbonate weathering. In general, divalent cations (Mg and Ca) and bicarbonate alkalinity derived from carbonate dissolution were higher than those from silicate weathering. As a consequence, the evolution of chemical species in the freshwaters of northern area of Okinawa Island to a large extent could be explained by mixing of two components, characterized by waters with Na+ and Cl− as predominant species and waters enriched with Ca2+ and HCO3−.
Flight initiation distances of five herbivores to approaches by vehicles in the Serengeti National Park, Tanzania
(John Wiley & Sons Ltd, 2008) Nyahongo, J. W.
The study was conducted in the SNP, Tanzania (14,763 km 2) from May 2001 to April 2002. Data were obtained in the western corridor (the relatively narrow, westerly extension of the park) and central areas (the main tourist area in the park around Seronera). Villages immediately bordered the southern boundary of the western corridor. In contrast, the nearest village was about 50 km from the central area. In the western corridor, there is a substantial amount of illegal hunting (Hofer et al., 1996; Loibooki et al., 2002) and illegal grazing carried out by villagers bordering the protected areas (Nyahongo et al., 2006)
Serengeti National Park and its neighbours–Do they interact?
(Elsevier, 2008) Kaltenborn, Bjørn P.; Nyahongo, Julius W.; Kidegesho, Jafari R.; Haaland, Hanne
Community-based management of protected areas has become a strong political objective worldwide. Many African countries have responded to this challenge, albeit with mixed results. Tanzania which is known for its abundant populations of wildlife in national parks has also developed several projects and institutions to improve people–park relationships. So far however, there is little evidence that community-based programmes have had any significant effect on management strategies, benefit distribution, or alleviating poverty. In this paper, we examine a part of this complex in the Western Corridor of Serengeti National Park in Tanzania. We address the basic questions of what is the extent of contact between park staff and the communities, what benefits are provided, and what needs do the communities see? There is little interaction between the park and adjacent communities, and while support is given to community projects, minimal benefits are distributed to the household or individual level. The current situation seems incapable of facilitating improved people–park relationships.
Spatial and temporal variation in meat and fish consumption among people in the western Serengeti, Tanzania: the importance of migratory herbivores
(2009) Nyahongo, J. W.; Holmern, T.; Kaltenborn, B. P.; Røskaft, E.
Illegal bushmeat hunting has become a serious problem for wildlife managers in many African countries. We investigated the spatial and temporal pattern in meat and fish consumption by people surrounding the Serengeti National Park, Tanzania, to understand better the links between hunting and consumption. We studied 150 households in five villages during March–December 2006 along a gradient from the Park boundary to 80 km away. In addition, two parallel 10 km transects were monitored monthly in areas within the National Park immediately adjoining three village areas to investigate the relationship between household meat consumption and the influx of migratory herbivores. We found that the number of meat meals was higher in the villages closest to the Park boundary and the weekly number of meat meals per household in all villages within 30 km of the Park boundary increased with the seasonal influx of migratory herbivores. Meat consumption was unrelated to household income except in the most distant village where there was a positive correlation. The number of fish meals in the villages closest to the Park decreased with the influx of migratory herbivores. We recommend a coordinated management of fish harvesting from Lake Victoria and wildlife conservation around the Serengeti National Park to implement sustainable management of these two ecologically different sources of animal protein.
Characterization of MSW and related waste-derived compost in Zanzibar municipality
(SAGE, 2010) Vuai, S. A. H.
The spread of municipal solid waste (MSW) in Zanzibar municipality has been associated with environmental pollution, unpleasant city conditions, contamination of water sources and coastal areas together with harbouring of malaria vectors. The contamination has a close relationship with eruption of diarrhoea, cholera and typhoid which claim the lives of the residents. Most of the wastes are of domestic and market origin and have the potential for compost production. This study examined the possibility of composting MSW from Zanzibar municipality as an alternative way of SW management and assessed the nutrient contents of the compost for application in agricultural production. Two major classes of SW were selected for the study: municipal solid waste and rice milling by-products. The samples were composted aerobically and anaerobically. The results showed that aerobic composting reduced about 60% of the waste volume. This volume reduction suggests that composting can be a promising SW management technique by reducing the large demand of space for landfilling. Municipal solid waste composted under anaerobic conditions produced compost with relatively higher concentrations of dissolved species than that produced under aerobic conditions. The trace metal contents were higher in MSW than in rice milling by-products. It was found that the unmanaged compost collected from the dumping site had low nutrient contents and was enriched with trace metals. Generally, physico-chemical characteristics, nutrients and trace metal levels suggest that Zanzibar municipal solid waste can produce high-quality compost for application to a wide range of soil types to improve their fertility, under proper management.
Geranylbenzoquinonoids from Lettowianthus stellatus fruits
(Taylor & Francis, 2010) Makangara, John J.; Nkunya, Mayunga H.H.; Jonker, Stephan S.
The geranylbenzoquinonoids 7-(3,7-dimethylocta-2,6-dienyl)-5-hydroxy-3H-benzofuran-2-one (lettowienolide), dimethyl 2,3-bis-[5-(3,7-dimethylocta-2,6-dienyl)-3,6-dioxocyclohexa-1,4-dienyl]-succinate (lettowiquinone), 2-(3,7-dimethylocta-2,6-dienyl)-6-[7-(3,7-dimethylocta-2,6-dienyl)-5-hydroxybenzofuran-2-yl]-[1,4]benzoquinone (lettowifuraquinone), methyl [3-(3,7-dimethylocta-2,6-dienyl)-6-methyl-5-(3-methylbut-2-enyl)-1,4-dioxo-1,5, 8,8a-tetrahydro-4H-nathphalen-4a-yl)]-acetate (lettowinone) and methyl [6-hydroxy-2-methyl-2-(4-methylpent-3-enyl)-2H-chromen-8-yl]-acetate (lettowipyraquinol) were isolated from fruits of Lettowianthus stellatus Diels, together with juvenile hormone III and 7-octadecen-9-ynoic acid. Lettowienolide and lettowiquinone exhibited mild in vitro activity against the Plasmodium falciparum malaria parasite (each IC50 ∼ 20 µg mL−1). Structural determination was achieved based on extensive analysis of spectroscopic data.
Black rhino conservation in Tanzania: translocation efforts and further challenges
(International Union for Conservation of Nature and Natural Resources., 2010) Fyumagwa, Robert D.; Nyahongo, Julius W.
Tanzania had many black rhinos (Diceros bicornis) in the 1960s but was hit by ruthless poaching between the 1970s and late 1980s. From the 1990s, the country declared a war against unscrupulous poachers in order to conserve the few remaining rhinos. The current strategy is to reintroduce black rhinos that were originally from East Africa in order to increase genetic diversity. Three translocations of black rhinos between 1997 and 2001 involved 10 animals from South Africa, two of which were reintroduced to Ngorongoro Crater and eight to Mkomazi National Park. In 2007, two black rhinos from Port Lympne Wild Animal Park, UK, were introduced into a sanctuary adjacent to Ikorongo-Grumeti Game Reserves. In June 2009, three black rhinos from the Czech Republic were translocated to Mkomazi National Park. Another translocation operation is expected to begin in May 2010 whereby 32 black rhinos will be translocated into the Serengeti ecosystem from Thaba Tholo, Thabazimbi, South Africa. Although the first five translocation operations went well, the challenge is the management of the reintroduced rhinos amid the growing social-ecological pressures affecting protected areas. Management authorities should consider the recommended sex ratio for rhino populations to avoid excessive male aggression.
Trend of trace metals in precipitation around Okinawa Island, Japan
(Elsevier, 2011) Vuai, S. A. H.; Tokuyama, A.
Okinawa Island is located between mainland Japan to the northeast, Taiwan to the southwest and China to the west. In recent years, precipitation with relatively low pH has been observed in the island during winter seasons. This study was conducted to evaluate the potential sources and factors affecting distribution of trace metals in the atmosphere around the northern area of Okinawa Island. The results showed that the trace metal contamination was low comparable to rural areas of less industrialized countries. The annual average depositions were 6.0, 5.2, 4.4, 2.7 and 20.4 kg km− 2 y− 1 for Al, Fe, Mn, Cu, and Zn, respectively. The metals in the precipitation were mainly derived from the dissolution of wind-blown soil particles. The distribution of trace metals across the island showed the influence of road traffic as a source and cause of atmospheric pollution. Aluminium and Fe were found to be high closer to the main road and decreased further away from the road, while Zn and Cu were strongly correlated with average mean pH of precipitation. The variation of concentrations in the island was attributed to the distance from the main road, average rain pH at a particular sampling location and wind speed and direction. A strong correlation between lithological elements (Al and Fe) and anthropogenic elements (Zn and Cu) indicates that they were carried by the same particles and experienced similar scavenging mechanism during dissolution process.
The attitudes of tourists towards the environmental, social and managerial attributes of Serengeti National Park, Tanzania
(Sage Publishing, 2011) Kaltenborn, Bjørn P.; Nyahongo, Julius W.; Kideghesho, Jafari R.
Serengeti National Park is a world class icon for wildlife tourism attracting a diverse group of tourists from all over the world. The park has played a pivotal role in protecting large populations of wildlife species of the Eastern African savannah and the globally outstanding biological phenomena such as the annual migration of wildebeest. However, the history of the park is also characterised by resource use conflicts and pressures that could threaten the current quality of the visitor environment. In this paper we examine the attitudes of international visitors toward the management and attributes of the park. Overall, the tourists report a high degree of satisfaction with most aspects of their trip. Yet, the current tourists are concerned about possible future changes that could alter the visitor environment and idealized images of the African wild lands. Basic environmental attitudes (degrees of ecocentrism) have effects on attitudes toward management of the park. Tourists expressing a high degree of ecocentrism are more likely to support management actions aimed at controlling tourism activities, access and impacts. They also express a stronger interest in experiencing nature, wilderness and local culture. The results are discussed in light of the major impact factors and conservation issues facing the management of Serengeti National Park; poaching, poverty in surrounding communities, increasing population pressure, habitat degradation, and wildlife diseases.
Typing of unknown microorganisms based on quantitative analysis of fatty acids by mass spectrometry and hierarchical clustering
(Elsevier, 2011) Li, Tingting; Dai, Ling; Li, Lun; Hu, Xuejiao; Dong, Linjie; Li, Jianjian; Salim, Sule Khalfan; Fu, Jieying; Zhong, Hongying
Periodic flooding and land use effects on soil properties in Lake Victoria basin
(Academic Journals, 2011) W., Nancy Mungai; M., Njue A.; G., Abaya Samuel; H., Vuai Said A.; D., Ibembe John
Frequent periodic flooding and land use changes taking place in the Lake Victoria basin (LVB) in east Africa may cause soil deterioration and further exacerbating food insecurity. Surface (0 to 20 cm) soil samples were collected at three locations along Sondu Miriu (Kenya) and Simiyu-Duma (Tanzania) rivers. Samples were collected from fields that were periodically flooded (1-28 d) and those that never flood, either under grass or crops. Samples were analysed for soil texture, organic carbon (OC), total nitrogen (TN), pH, extractable phosphorus (P), exchangeable potassium (K) and B-glucosidase activities. B-glucosidase activities, clay and P contents were higher in some of the soils that flood, while OC, exchangeable K and sand contents were lower at P< 0.05 in flooded soils. Observed differences account for 11% of comparisons in the two river basins. Soils under grass had higher B-glucosidase activities and silt content but lower sand content than cultivated soils in 6% of samples in the two basins. However, conversion of natural ecosystems to grassland or cropped lands resulted in a 17 to 113% reduction in OC, TN, and exchangeable K in Sondu, and a 129% decline in TN in Simiyu. Soil properties exhibited clear but different patterns from upstream to downstream in the two basins. OC, TN, clay and B-glucosidase activities were higher in Sondu upstream, while OC, TN, extractable P and exchangeable K were lower in Simiyu upstream. Observed difference across each basin underscore the importance of inherent soil characteristics in influencing soil properties compared to short-term flooding or short duration changes in land use.
Effects of sand mining on land degradation and plant species diversity: a case study of north b district of Unguja region, Zanzibar
(The University of Dodoma, 2011) Ali, Wahida M.
A study was carried out to assess effects of sand mining on land degradation and plant species diversity in North „B‟ district, Zanzibar based on specific objectives to: (1) investigate community perception on sand mining, (2) asses impact of sand mining on socio-economic activities among small holder farmers,(3) determine effect sand mining on land degradation. The study also aimed (4) to determine effect of sand mining on plant species biodiversity, (5) to identify important strengths, weaknesses, opportunities and challenges (SWOT) on sustainable mining and (6) to investigate efforts undertaken among local communities to overcome ecological threats due to sand mining. Structured and semi-structured questionnaires were enumerated among 120 respondents from three villages, with intense sand mining namely, Donge, Kazole and Pangatupu compared to Mahonda village which was used as a positive control. Socio-economic survey was coupled with interviews and panel discussions. Effect of sand mining on plant species diversity was assessed using 18 square sample plots of 20 m x 20 m. Data on the effect of sand mining on land degradation were analyzed using Statistical Package for Social Services (SPSS). Sand mining was attributed land degradation (85.6%), low agricultural productivities (64.4%), shortage of agricultural land (55.8%) and soil erosion (38.8%). Data on plant species were analysed using Statistical Analytical System (SAS) and result were: Index of dominance (C) of shrubs species ranged from 0.14- 0.19 and tree species range from 0.11- 0.15.Shannon-Weiner index diversity (H‟) of shrubs species ranged from 1.18- 1.98 and tree species ranged from 2.08- 2.3. Sand mining with associated with decreased plant species diversity as indicated by 0.12 shrub species, 0.10 tree species index of dominance and Shannon - Weiner index of diversity 2.18 shrub species, 2.69 tree species for Mahonda non – mined site. The study concludes that, to identify strengths that people have knowledge on conservation especial on land degradation and plant species. It is recommended that, the government in collaboration with other stake holders should make special effort to mobilize the community to participate in controlling campaign against adverse effects of sad mining

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