Groundwater salinity in a semi-arid region of central-eastern Tunisia: insights from multivariate statistical techniques and geostatistical modelling

2019 ◽  
Vol 78 (10) ◽  
Author(s):  
S. M’nassri ◽  
L. Dridi ◽  
G. Schäfer ◽  
M. Hachicha ◽  
R. Majdoub
Keyword(s):  
Arid Region ◽  
Statistical Techniques ◽  
Groundwater Salinity ◽  
Multivariate Statistical Techniques ◽  
Multivariate Statistical ◽  
Geostatistical Modelling ◽  
Central Eastern ◽  
Semi Arid Region ◽  
Semi Arid

scholarly journals Characterization agricultural vulnerability to drought in the Northeast of Brazil

2017 ◽  
Author(s):  
Bruce K. N. Silva ◽  
Paulo S. Lucio ◽  
Cláudio M. S. Silva ◽  
Maria H. C. Spyrides ◽  
Madson T. Silva ◽  
...  
Keyword(s):  
Arid Region ◽  
Early Warning Systems ◽  
Demographic Characteristics ◽  
Moderate Degree ◽  
Warning Systems ◽  
Multivariate Statistical ◽  
Agricultural Vulnerability ◽  
Agricultural Census ◽  
Semi Arid Region ◽  
Semi Arid

Abstract. The main objective was to create an indicator of agricultural vulnerability to drought in the Northeast of Brazil (NEB). The data used for precipitation belong to ANA (Agência Nacional das Águas) considering the climatological norm from 1979–2008. Data on agricultural productivity and demographic characteristics were obtained in the agricultural census of IBGE (Brazilian Institute of Geography and Statistics) in 2006 and, finally, data on natural disasters in the period 1991–2010 with CEPED (Centro de Estudose Pesquisasem Engenhariae Defesa Civil). The Multivariate Statistical Analysis Factorial technique allowed to reduce the number of variables and to estimate a model of the sensitivity component that reproduced 42 % of the original variance, besides the factors trying to represent the productive dynamics of the NEB. The results show that the Southern NEB presented the highest degree of agricultural vulnerability (17,81–121,44) in the 2000 census, when compared to the census of 2010. In the Southwest it is observed that a part of the semi-arid region presented a moderate degree (0,74–1,08) and much higher in extension when compared to the 2000 census, evidencing that exposure to drought does not directly influence the agricultural sensitivity in the most productive areas of the region. The adaptive capacity factor presented significant results for the composition of the indicator of agricultural vulnerability, mainly in the semi-arid region that varied from (0,71–5,42). In this way, it is concluded that, between the census, the southern and central part of the NEB reduced agricultural vulnerability, but the region should benefit from early warning systems as well as the development and adoption of natural resources and technology management, with the objective of ducating producers about the potential impacts of extreme events.

scholarly journals Temporal variation in fish composition and abundance in a perennial tributary of the rio Paraguaçu, a little-known drainage in the Brazilian semi-arid region

2011 ◽  
Vol 9 (1) ◽  
pp. 153-160 ◽  
Author(s):  
Alexandre Clistenes de A. Santos ◽  
Érica P. Caramaschi
Keyword(s):  
Temporal Variation ◽  
Arid Region ◽  
Fish Community ◽  
Environmental Parameters ◽  
Fish Community Structure ◽  
Multivariate Statistical ◽  
Perennial Stream ◽  
Semi Arid Region ◽  
Semi Arid

The rio Santo Antônio is a perennial lowland stream in the Brazilian semi-arid region, and is the main tributary of the upper rio Paraguaçu, an important drainage of the Chapada Diamantina. The temporal variation of the fish composition and abundance in a stretch of the middle course of the river was evaluated. Sampling was carried out monthly between August 1998 and July 1999, using standardized gear and techniques. Data on water and air temperature, water transparency, maximum and mean depth, width and area of the channel, and flow were recorded on each fish sampling occasion. Univariate and multivariate statistical analyses were employed in order to detect significant temporal differences in environmental parameters and fish abundance. Temperature, transparency and channel depth drove opposite tendencies between the dry and rainy months. The fish community richness (32) and composition did not change between these periods, but large fish caught with gillnets were more abundant in the rainy months. We conclude that the undramatic disturbance in the hydrological stream conditions between the dry and rainy periods led to weak responses of the fish assemblage. Long-term monitoring would be necessary, however, to assess the real persistence of the fish community structure in this perennial stream.

The Molecular Characterization and Biological Assessment of the Leaves Extracts of Loofah Reveal their Nutraceutical Potential

2020 ◽  
Vol 11 ◽  
Author(s):  
Takoua Ben Hlel ◽  
Feten Belhadj ◽  
Fatih Gül ◽  
Muhammed Altun ◽  
Ayşe Şahin Yağlıoğlu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Phenolic Compounds ◽  
Hela Cell ◽  
Arid Region ◽  
Biological Properties ◽  
Biological Assessment ◽  
Omega 3 ◽  
Hela Cell Lines ◽  
Semi Arid Region ◽  
Semi Arid

Background:: Luffa cylindrica is a plant that is widely distributed in Africa and Asia and it can be grown in regions with tropical or subtropical climates. Few patents dealt with Loofah biological properties, including some functional foods formulated from its leaves. Objective:: This study aimed to structurally and functionally characterize the bioactive compounds of L. cylindrica leaves grown in two different environments. Methods:: The extracts of L. cylindrica leaves collected from two Tunisian locations: Essouasi (LE), a semi-arid region and Medenine (LM) an arid region, were investigated for their phenolic compounds and fatty acids using HPLC/TOF-MS and GCMS techniques respectively. Furthermore, the antioxidant capacity was evaluated with DPPH, Chelating effect, Hydroxyl radical and Superoxide anion scavenging activities while the anticancer activity against HeLa cell lines was assessed using xCELLigence real time cell analyzer and lactate dehydrogenase cytotoxicity assay. Results:: The antiproliferative capacity of both extracts was time and dose-dependent with LE presenting the lowest HeLa cell index (CI = 0.035 ± 0.018, 250 μg/ml). LE also showed the best cytotoxic capacity (56.49 ± 0.8%) and antioxidant potential (IC50 = 54.41 ± 1.12 μg/ml for DPPH and 12.12 ± 0.07 μg/ml for chelating effet). 14 phenolic compounds were detected in LE with ferulic acid being the major compound (5128.5 ± 4.09 μg Phenols/g) while LM had only 6 phenolics. GCMS analysis showed the presence of omega-3 fatty acids in LE. Conclusions:: Our findings suggest that L. cylindrica leaves, especially when collected from semi-arid regions, are promising for formulating nutraceuticals of interest.

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