5 resultados para environmental problems

em SAPIENTIA - Universidade do Algarve - Portugal


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Dissertação de Mestrado, Gestão da Água e da Costa, Faculdade de Ciências e Tecnologia, Universidade do Algarve, University of Plymouth, Universidad de Cadiz, 2010

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Ecohydrology is a scientific concept applied to problem- solving in environmental issues. It recognises that the present practice of relying nearly exclusively on engineering fixes to solve environmental problems is failing to restore the aquatic environment to a level that can sustain the quality of life that people are demanding. Ecohydrology is based on the ability of science to quantify and explain the relationships between hy- drological processes and biotic dynamics at a catchment scale and to manipulate these processes to increase the robustness of the aquatic system and thus its ability to cope with human- induced stresses. The concept was developed by the UNESCO International Hydrologic Programme (IHP) and the Man and Biosphere Programme (MAB).

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Infectious diseases often hamper the production of aquatic organisms in aquaculture systems, causing economical losses, environmental problems and consumer safety issues. The conventional way aquaculture producers had to control pathogens was by means of synthetic antibiotics and chemicals. This procedure had consequences in the emergence of more resilient pathogens, drug contamination of seafood products and local ecosystems. To avoid the repercussions of antibiotic use, vaccination has greatly replaced human drugs in western fish farms. However there is still massive unregulated antibiotic use in third world fish farms, so less expensive therapeutic alternatives for drugs are desperately needed. An alternative way to achieve disease control in aquaculture is by using natural bioactive organic compounds with antibiotic, antioxidant and/or immunostimulant properties. Such diverse biomolecules occur in bacteria, algae, fungi, higher plants and other organisms. Fatty acids, nucleotides, monosaccharides, polysaccharides, peptides, polyphenols and terpenoids, are examples of these substances. One promising source of bioactive compounds are salt tolerant plants. Halophytes have more molecular resources and defence mechanisms, when compared with other tracheophytes, to deal with the oxidative stresses of their habitat. Many halophytes have been used as a traditional food and medical supply, especially by African and Asian cultures. This scientific work evaluated the antibiotic, antioxidant, immunostimulant and metal chelating properties of Atriplex halimus L., Arthrocnemum macrostachyum Moric., Carpobrotus edulis L., Juncus acutus L. and Plantago coronopus L., from the Algarve coast. The antibiotic properties were tested against Listonella anguillarum, Photobacterium damselae piscicida and Vibrio fischeri. The immunostimulant properties were tested with cytochrome c and Griess assays on Sparus aurata head-kidney phagocytes. J. acutus ether extract inhibited the growth of P. damselae piscicida. A. macrostachyum, A. halimus, C. edulis, Juncus acutus and P. coronopus displayed antioxidant, copper chelating and iron chelating properties. These plants show potential as sources of bioactive compounds with application in aquaculture and in other fields.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Dissertação de mest. em Gestão e Conservação da Natureza, Faculdade de Ciências do Mar e do Ambiente, Univ. do Algarve, 2006

Relevância:

40.00% 40.00%

Publicador:

Resumo:

The problem with the adequacy of radial basis function neural networks to model the inside air temperature as a function of the outside air temperature and solar radiation, and the inside relative humidity in an hydroponic greenhouse is addressed.