Abstract

Contamination of drinking water by microorganisms represents a major human health hazard in many parts of the world. The main objective of drinking water treatment is to provide microbiologically safe drinking water. The conventional drinking water treatment and disinfection has proved to be one of the major public health advances in modern times. A number of processes; namely water treatment, disinfection and changes influence the quality of drinking water delivered to the customer’s tap during transport of treated water via the distribution system. At least 325 water-associated outbreaks of parasitic protozoan disease have reported. In this study, drinking water from treatment plants evaluated for the presence of parasitic protozoa. Water samples collected from two main points: (a) outlet of the water treatment plants (b) distribution system at different distances from the water treatment plants. Protozoa were concentrated from each water sample by adsorption and accumulation on the nitrocellulose membrane filters (0.45 μm pore size) and detected by conventional staining methods.

DOI number: 10.5027/jnrd.v2i0.03

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Abstract

This paper provides a set of indices based on emergy analysis for the Côrrego Sujo basin, Teresópolis- Brazil. Encompassing natural and agricultural systems, the Côrrego Sujo basin has been affected by destruction and fragmentation of natural habitats and unsustainable land use practices. The main objective is to evaluate the environmental impact of the land use systems, the load capacity and the use of natural and economic resources. The studied land use systems were: i) agriculture, ii) grassland and cattle, iii) rainforest and iv) forest in regeneration stage (fallow: 1, 2 and 3 years old). Emergy analysis integrates all flows within a system of coupled economic and environmental work in common biophysical units (solar emjoules – seJ). The main conclusions of the study are: the basin does not have dependence of purchased resources and the environmental impact is moderate; the efficiency of the basin as a system is highly positive and it represents a positive contribution to the economy; the emergy exchange ratio is moderate and; the biggest contributions to the system come from natural sources showing that the ecological sustainability is moderate to good.

DOI number: 10.5027/jnrd.v2i0.02

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Abstract

Conservation of forest genetic resources is essential for sustaining the environmental and productive values of forests. One of the environmental values is the conservation of the diversity that is assessed through the amount of genetic diversity stored by forests, their structure and dynamics. The current need for forest conservation and management has driven a rapid expansion of landscape genetics discipline that combines tools from molecular genetics, landscape ecology and spatial statistics and is decisive for improving not only ecological knowledge but also for properly managing population genetic resources. The objective of this study is to show the way to establish the safeguard of genetic diversity through this approach using the results obtained in sweet chestnut (Castanea sativa Mill.) that has provided a better understanding on the species genetic resources. In this respect, we will show how the information provided by different types of molecular markers (genomic and genic) offer more accurate indication on the distribution of the genetic diversity among and within populations assuming different evolutionary drivers.

DOI number: 10.5027/jnrd.v2i0.01

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Abstract

Water rather than land is the limiting factor for crop production in Sudan. This study attempts to use the water footprint (WFP) and virtual water concepts to account for crops water consumption under the Sudanese rainfed and irrigated conditions. The general average of the green WFP of sorghum and millet were found to be about 7700 and 10700 m3 ton-1, respectively. According to experimental results at three different climates, in-situ rainwater harvesting techniques could reduce the WFP of rainfed sorghum by 56% on the average. The blue component (surface water) shows the highest contribution to the total WFP of irrigated crops: 88% for cotton, 70% for sorghum, 68% for groundnut and 100% for wheat. However, the role of the green water (rainwater) is not marginal since it largely influences the operation and maintenance (silt clearance) of the gravity-fed irrigation system. Under normal conditions, the annual total virtual water demand of sorghum (the dominant food crop in Sudan) is found to be 15 km3, of which 91% is green water. During a wet year a surplus of 5 km3 of water can be saved. During a dry year, however, Sudan could experience a deficit of 2.3 km3 of water, necessitating the adoption of a wise food stocking-exporting policy.

DOI number: 10.5027/jnrd.v1i0.03

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Abstract

This article outlines environment friendly features, climate responsive features and construction features of a prototype school building constructed using green building technology. The school building has other additional features such as earthquake resistant construction, use of local materials and local technology. The construction process not only establishes community ownership, but also facilitates dissemination of the technology to the communities. Schools are effective media for raising awareness, disseminating technology and up-scaling the innovative approach. The approach is cost effective and sustainable for long-term application of green building technology. Furthermore, this paper emphasizes that such construction technology will be instrumental to build culture of safety in communities and reduce disaster risk.

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Abstract

Mexico is characterized by a remarkable richness of Opuntia, mostly at the Meridional Highlands Plateau; it is also here where the greatest agrobiodiversity of Opuntia variants occurs. Most of these variants have been maintained in homegardens; however, the gathering process which originated these homegardens has been disrupted over the past decades, as a result of social change and the destruction of large wild nopaleras (cactus shrub land). If the variants still surviving in homegardens are lost, these will be hard to recover, that is, the millenary cultural heritage from the human groups that populated the Mexican Meridional Highland Plateau will be lost forever. This situation motivated the preparation of a catalogue that records the agrobiodiversity of wild and cultivated Opuntia variants living in the meridional Highlands Plateau. To this end, 379 samples were obtained in 29 localities, between 1998 and 2003. The information was processed through Twinspan. All specimens were identified and preserved in herbaria. Botanical keys and descriptions were elaborated. The catalogue includes information on 126 variants comprising 18 species. There were species with only one variant (Opuntia atropes, O. cochinera, O. jaliscana, O. leucotricha, O. rzedowskii and O. velutina), two (O. durangensis, O. lindheimeri, O. phaeacantha and O. robusta), five (O. joconostle and O. lasiacantha), seven (O. chavena), 12 (O. hyptiacantha and O. streptacantha), 15 (O. ficus-indica), 22 (O. albicarpa), and up to 34 (O. megacantha). Additionally, 267 common cactus pear names were related to those variants.

DOI number: 10.5027/jnrd.v1i0.01

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