Local perceptions of risk to livelihood in semi-arid Tanzania

This paper examines variation in local perceptions of risk in semi-arid Tanzania, identifying factors that influence local perceptions of problems and testing the feasibility of risk mapping as a technique. Twelve villages in six districts were visited between February and April 2001. Villagers were asked about their worries and concerns in providing for themselves and their families using a risk questionnaire. The responses were grouped into 21 categories of problem and incidence and severity indices were calculated for each category. Most problems were associated with the availability of natural resources on which livelihoods depend but others related to human and social capital assets. In addition to environmental factors, livelihood strategy and gender both influenced people's perceptions of risk. Problems of irrigation and weather, for example, were important for agricultural communities while problems relating to livestock diseases, access to land and hunger were more important in pastoral communities. The risks cited by men and women generally reflected their traditional roles in society. Very broadly, the risks associated with natural capital tended to be seen as higher by men while women mentioned more problems relating to human and social capital. However, this was not always the case. Problems linked to finance, traditionally the concern of men, were ranked similarly by men and women. In projects designed to facilitate community management and control over common pool resources, the identification of common interests is particularly important. Risk mapping can provide a cost-effective way of gaining insights to help improve research design and to inform policy development.     

Oxidative damage to Pseudomonas aeruginosa ATCC 27833 and Staphylococcus aureus ATCC 24213 induced by CuO-NPs

Environmental Science and Pollution Research - The cytotoxicity of nanoparticles (NPs) and their properties are important issues in nanotechnology research. Particularly, NPs affect the metabolism...     

Assesment of Trace Elements and Organic Pollutants from a Marine Oil Complex into the Coral Reef System of Cayo Arcas, Mexico

Possible contaminants produced by the Petroleos Mexicanos (PEMEX) marine oil complex in the vicinity of the Cayo Arcas (Mexico) coral reef ecosystem were evaluated by analyzing sediments and sea water for hydrocarbons and metal elements. We found that the concentrations of aliphatic hydrocarbons in the sea water were generally low, with the highest values detected near the oil station; the concentration of polycyclic aromatic hydrocarbons (PAHs) was generally below the detection limit. The hydrocarbons found in the sediments seem to have a pyrogenic origin, and were probably produced by marine traffic in the study area. The total PAH concentration did not exceed the NOAA criteria, although levels of some individual PAHs did. The only metal detected in the sea water at high concentrations was nickel. The Ni/V ratio in the sediments indicates the contribution of crude oil to the system. The high content of Ni and Zn was attributed to the ballast waters from the oil tankers that load at the station's monobuoys. The presence of fine sediments that commonly originate from terrestrial ecosystems supported this assumption.     

Design principles and common pool resource management: an institutional approach to evaluating community management in semi-arid Tanzania

This paper analyses the role of institutions in the management of common pool resources (CPRs) in semi-arid Tanzania. Common property regimes have often been considered inadequate for the management of CPRs because of the problems of excludability, but they are becoming more widely supported as the way forward to overcome the problems of resource use and degradation in developing countries. A series of design principles for long enduring common property institutions have been proposed by Ostrom, but there is concern that they are not applicable to a wide range of real life situations or that they may be specific to certain types of CPR. Here, we compare these principles to the situation prevailing in 12 villages in six districts in semi-arid Tanzania. Data on management institutions were collected through semi-structured interviews and meetings at district and village level. The combined information was used to make a qualitative assessment of the strength with which each design principle appeared to operate in the management of forest, pasture and water resources. Boundaries, conflict and negotiation in CPR management are of key importance in semi-arid regions. However, the need for flexibility in order to deal with ecological uncertainty means that many management institutions would be considered weak or absent according to the design principle approach. This supports the view that the design principles should not be used as a 'blueprint to be imposed on resource management regimes' rather that they provide a framework for investigating common property regimes with the proviso that, certainly for semi-arid regions, they may highlight where management cannot be explained by institutional theory alone.     

Space for equity: socioeconomic variations in the provision of public parks in Hermosillo,Mexico

This article examines the intersection between globalisation and allocation of open public space by testing the spatial equity hypothesis in Hermosillo, Mexico, a regional city impacted directly by global processes. Availability and accessibility of public parks were examined using a geographic information system and neighbourhoods were stratified into quintiles based on socioeconomic status. Overall, the analysis shows that the amount of public park space in Hermosillo is substandard and its distribution reveals a pattern of spatial inequity affecting primarily residents of poor neighbourhoods. We argue that as the economy of the city grows increasingly integrated into global circuits, the global-to-local connection materialises in an unequal competition between globalised spaces and local public space. This, in turn, leads to further relegation of neighbourhoods that are already on the margins of urban equity regarding access to public parks. This study extends prior research conducted in developed countries to a city in a developing nation and fills a vacuum of information that potentially can contribute to a more equitable development in Hermosillo.     

Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium<Emphasis Type="Italic"> Azospirillum</Emphasis> spp.

In vitro gluconic acid formation and phosphate solubilization from sparingly soluble phosphorus sources by two strains of the plant growth-promoting bacteria A. brasilense (Cd and 8-I) and one strain of A. lipoferum JA4 were studied. Strains of A. brasilense were capable of producing gluconic acid when grown in sparingly soluble calcium phosphate medium when their usual fructose carbon source is amended with glucose. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. To a greater extent, gluconic acid production and pH reduction were observed for A. lipoferum JA4. For the three strains, clearing halos were detected on solid medium plates with calcium phosphate. This is the first report of in vitro gluconic acid production and direct phosphate solubilization by A. brasilense and the first report of P solubilization by A. lipoferum. This adds to the very broad spectrum of plant growth-promoting abilities of this genus.     

Metal and nutrient dynamics in a eutrophic coastal lagoon (Óbidos, Portugal): the importance of observations at different time scales

Water and sediment quality was monitored at four sites of Óbidos coastal lagoon (Portugal) in February, May, July and October 2006, covering different hydrological conditions. Concentrations of nutrients and metals increased in autumn/winter, particularly in an inner branch with symptoms of eutrophication that receives a small tributary contaminated by agro-industrial activities. Moreover, concentrations of PO₄ ^3?, Si(OH)₄ and Mn (diffusive gradients of thin films (DGT)-measured) varied inversely with salinity. Additionally, that branch was monitored over 26-h in July 2006 to assess variations of water quality parameters, nutrients and metals on short timescale. During the night, O₂ in water reached a minimum of 40% saturation followed by a pronounced increase of DGT-measured metals and nutrients in water column: Fe and Mn (ten times); Cr, Co, PO₄ ^3? and Si(OH)₄ (six times). Enhancements were also registered for metal/Al ratios in suspended particulate matter: Mn, Cr and Cd (four to six times); Fe, Ni and Co (1.5 times). The metal distribution coefficients calculated along the 26-h survey showed a maximum at daylight suggesting a preferential association of metals with suspended particles. Data recorded under different hydrological conditions and over the 26-h survey allowed to address the influence of external and internal sources on water quality. The results of this study highlight the importance of day/night cycles on the availability of nutrients and metals in eutrophic environments.     

Sexual size dimorphism in fallow deer (Dama dama): do larger, heavier males gain greater mating success?

Sexual size dimorphism may evolve as a result of both natural and sexual selection. In polygynous mammals, the main factor resulting in the evolution of large body size in males is the advantage conferred during competition for mates. In this study, we examined whether sexual selection acts on body size in mature fallow bucks (Dama dama) by examining how the following traits are inter-related: age, body (skeletal) size, body mass, prerut dominance rank, rut dominance rank and mating success. This is the first study to examine how all these factors are together related to the mating success of a large sexually dimorphic and polygynous mammal. We found that male mating success was directly related to body size, but not to body mass. However body mass was related to prerut dominance rank which was in turn strongly related to rut dominance rank, and thus there was an indirect relationship between mating success and body mass. Rut dominance rank was the variable most strongly related to mating success. Mating success among mature males was unrelated to age. We conclude that larger mature fallow bucks have advantages over other males when competing for matings, and sexual selection therefore continues to act on sexual size dimorphism in this species. Heavier fallow bucks also have advantages, but these are mediated through the dominance ranks attained by males before the rut.