Rich ecosystems such as estuaries and brackish lakes are vulnerable to the effects of human activ... more Rich ecosystems such as estuaries and brackish lakes are vulnerable to the effects of human activities and are prone to environmental changes. In particular, the salt environment, which is the backbone of the environment, might be affected not only by direct modifications such as dredging but also in ways that were not initially envisioned. Ichkeul Lake, located in the northern part of Tunisia, is a shallow brackish lake registered as a UNESCO World Natural Heritage Site. The construction of reservoirs upstream of the inflowing river in the 1980s reduced the amount of freshwater inflow. That only had been thought to be the cause of the increase in salinity in Ishkeul Lake. On the other hand, the sedimentation in the reservoirs upstream was remarkable, and the supply of sediment from the reservoirs upstream to the Ichkeul Lake was stopped. Changes in sediment outflow may have reduced lakebed altitude and enhanced seawater intrusion. However, the environmental protection measures for ...
Http Dx Doi Org 10 1080 02626667 2013 800202, Jun 27, 2013
ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeaster... more ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeastern Tunisia. The area is known for its intensive agriculture, which is based mainly on groundwater exploitation. The aim of this study is to identify the sources of groundwater salinization in the Wadi Al Ayn aquifer system and deduce the processes that drive the mineralization. Surface water and groundwater samples were taken and analysed for major ions and stable isotopes. The geochemical data were used to characterize and classify the water samples based on a variety of ion plots and diagrams. Stable isotopes are useful tools to help us understand recharge processes and to differentiate between salinity origins. The oilfield brines infiltrated from the sandy bed of Wadi Al Ayn comprise the main source of groundwater salinization in the central part of the plain, while seawater intrusion is mainly responsible for the increased salinity in the groundwater of the coastal part of the plain (at Daroufa).
ABSTRACT by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://cr... more ABSTRACT by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and peer-review under responsibility of the SustaiN conference committee and supported by Kyoto University; (RISH), (OPIR), (GCOE-ARS) and (GSS) as co-hosts Abstract
Biochemical and Biophysical Research Communications, 2013
6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extr... more 6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extract of Marrubium vulgare L. as an agonist of peroxisome proliferator-activated receptor γ (PPARγ). Fibrogenesis caused by hepatic stellate cells is inhibited by PPARγ whose ligands are clinically used for the treatment of diabetes. Plant extracts of Marrubium vulgare L., were screened for activity to inhibit fibrosis in the hepatic stellate cell line HSC-T6 using Oil Red-O staining, which detects lipids that typically accumulate in quiescent hepatic stellate cells. A methanol extract with activity to stimulate accumulation of lipids was obtained. This extract was found to have PPARγ agonist activity using a luciferase reporter assay. After purification using several chromatographic methods, 6-ODA, a fatty acid with a triple bond, was identified as a candidate of PPARγ agonist. Synthesized 6-ODA and its derivative 9-octadecynoic acid (9-ODA), which both have a triple bond but in different positions, activated PPARγ in a luciferase reporter assay and increased lipid accumulation in 3T3-L1 adipocytes in a PPARγ-dependent manner. There is little information about the biological activity of fatty acids with a triple bond, and to our knowledge, this is the first report that 6-ODA and 9-ODA function as PPARγ agonists.
Bulletin of environmental contamination and toxicology, Jan 8, 2015
Potential contamination of the sediments in the Sebkha of Moknine (Tunisia) ecosystem was assesse... more Potential contamination of the sediments in the Sebkha of Moknine (Tunisia) ecosystem was assessed by means of enrichment factors (EFs) estimated against reference sediment located ≈70 km away from the Sebkha. The use of EFs is recommended as a reliable method for heavy metal contamination assessment, provided that (1) element contents are corrected following a careful normalization procedure, and (2) the reference sediment is unaffected by anthropogenic alterations. The degree of contamination was assessed by the modified contamination degree approach. The obtained results indicated that surface sediments were enriched up to 22.9, 13.2, 5.46 and 3.19 times with Pb, Cu, Cr and Zn, respectively. Lower enrichment factors for Ni and Co suggested that anthropogenic sources were less important for these metals. The modified degree of contamination showed that the sediments in the Sebkha of Moknine have suffered significant systematic heavy metal contamination following catchment urbaniza...
ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeaster... more ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeastern Tunisia. The area is known for its intensive agriculture, which is based mainly on groundwater exploitation. The aim of this study is to identify the sources of groundwater salinization in the Wadi Al Ayn aquifer system and deduce the processes that drive the mineralization. Surface water and groundwater samples were taken and analysed for major ions and stable isotopes. The geochemical data were used to characterize and classify the water samples based on a variety of ion plots and diagrams. Stable isotopes are useful tools to help us understand recharge processes and to differentiate between salinity origins. The oilfield brines infiltrated from the sandy bed of Wadi Al Ayn comprise the main source of groundwater salinization in the central part of the plain, while seawater intrusion is mainly responsible for the increased salinity in the groundwater of the coastal part of the plain (at Daroufa).
Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering), 2011
ABSTRACT Sedimentation is a big problem in the sense of sustainability of surface water resource,... more ABSTRACT Sedimentation is a big problem in the sense of sustainability of surface water resource, especially in North Africa under the Mediterranean climate system. The counter measure to that problem is simply dredging but it has not been carried out in North African countries due to the financial reason. In this study, the present condition of sedimentation on the reservoir in Tunisia is reported and the practical countermeasure to that problem is suggested with regard to the possibility of using sediment as soil amelioration for alkaline saline soil which is very serious in North Africa.First, the bathymetric survey was carried out in order to grasp the development of sedimentation. And then, the water quality parameters were observed for the discussion of mass transfer in the water body. Finally, humic substances which can play a role of soil amelioration for saline alkaline soil are confirmed in the sediment sample.
Rich ecosystems such as estuaries and brackish lakes are vulnerable to the effects of human activ... more Rich ecosystems such as estuaries and brackish lakes are vulnerable to the effects of human activities and are prone to environmental changes. In particular, the salt environment, which is the backbone of the environment, might be affected not only by direct modifications such as dredging but also in ways that were not initially envisioned. Ichkeul Lake, located in the northern part of Tunisia, is a shallow brackish lake registered as a UNESCO World Natural Heritage Site. The construction of reservoirs upstream of the inflowing river in the 1980s reduced the amount of freshwater inflow. That only had been thought to be the cause of the increase in salinity in Ishkeul Lake. On the other hand, the sedimentation in the reservoirs upstream was remarkable, and the supply of sediment from the reservoirs upstream to the Ichkeul Lake was stopped. Changes in sediment outflow may have reduced lakebed altitude and enhanced seawater intrusion. However, the environmental protection measures for ...
Http Dx Doi Org 10 1080 02626667 2013 800202, Jun 27, 2013
ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeaster... more ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeastern Tunisia. The area is known for its intensive agriculture, which is based mainly on groundwater exploitation. The aim of this study is to identify the sources of groundwater salinization in the Wadi Al Ayn aquifer system and deduce the processes that drive the mineralization. Surface water and groundwater samples were taken and analysed for major ions and stable isotopes. The geochemical data were used to characterize and classify the water samples based on a variety of ion plots and diagrams. Stable isotopes are useful tools to help us understand recharge processes and to differentiate between salinity origins. The oilfield brines infiltrated from the sandy bed of Wadi Al Ayn comprise the main source of groundwater salinization in the central part of the plain, while seawater intrusion is mainly responsible for the increased salinity in the groundwater of the coastal part of the plain (at Daroufa).
ABSTRACT by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://cr... more ABSTRACT by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and peer-review under responsibility of the SustaiN conference committee and supported by Kyoto University; (RISH), (OPIR), (GCOE-ARS) and (GSS) as co-hosts Abstract
Biochemical and Biophysical Research Communications, 2013
6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extr... more 6-Octadecynoic acid (6-ODA), a fatty acid with a triple bond, was identified in the methanol extract of Marrubium vulgare L. as an agonist of peroxisome proliferator-activated receptor γ (PPARγ). Fibrogenesis caused by hepatic stellate cells is inhibited by PPARγ whose ligands are clinically used for the treatment of diabetes. Plant extracts of Marrubium vulgare L., were screened for activity to inhibit fibrosis in the hepatic stellate cell line HSC-T6 using Oil Red-O staining, which detects lipids that typically accumulate in quiescent hepatic stellate cells. A methanol extract with activity to stimulate accumulation of lipids was obtained. This extract was found to have PPARγ agonist activity using a luciferase reporter assay. After purification using several chromatographic methods, 6-ODA, a fatty acid with a triple bond, was identified as a candidate of PPARγ agonist. Synthesized 6-ODA and its derivative 9-octadecynoic acid (9-ODA), which both have a triple bond but in different positions, activated PPARγ in a luciferase reporter assay and increased lipid accumulation in 3T3-L1 adipocytes in a PPARγ-dependent manner. There is little information about the biological activity of fatty acids with a triple bond, and to our knowledge, this is the first report that 6-ODA and 9-ODA function as PPARγ agonists.
Bulletin of environmental contamination and toxicology, Jan 8, 2015
Potential contamination of the sediments in the Sebkha of Moknine (Tunisia) ecosystem was assesse... more Potential contamination of the sediments in the Sebkha of Moknine (Tunisia) ecosystem was assessed by means of enrichment factors (EFs) estimated against reference sediment located ≈70 km away from the Sebkha. The use of EFs is recommended as a reliable method for heavy metal contamination assessment, provided that (1) element contents are corrected following a careful normalization procedure, and (2) the reference sediment is unaffected by anthropogenic alterations. The degree of contamination was assessed by the modified contamination degree approach. The obtained results indicated that surface sediments were enriched up to 22.9, 13.2, 5.46 and 3.19 times with Pb, Cu, Cr and Zn, respectively. Lower enrichment factors for Ni and Co suggested that anthropogenic sources were less important for these metals. The modified degree of contamination showed that the sediments in the Sebkha of Moknine have suffered significant systematic heavy metal contamination following catchment urbaniza...
ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeaster... more ABSTRACT The Wadi Al Ayn plain is a coastal system on the eastern coast of Cap Bon in northeastern Tunisia. The area is known for its intensive agriculture, which is based mainly on groundwater exploitation. The aim of this study is to identify the sources of groundwater salinization in the Wadi Al Ayn aquifer system and deduce the processes that drive the mineralization. Surface water and groundwater samples were taken and analysed for major ions and stable isotopes. The geochemical data were used to characterize and classify the water samples based on a variety of ion plots and diagrams. Stable isotopes are useful tools to help us understand recharge processes and to differentiate between salinity origins. The oilfield brines infiltrated from the sandy bed of Wadi Al Ayn comprise the main source of groundwater salinization in the central part of the plain, while seawater intrusion is mainly responsible for the increased salinity in the groundwater of the coastal part of the plain (at Daroufa).
Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering), 2011
ABSTRACT Sedimentation is a big problem in the sense of sustainability of surface water resource,... more ABSTRACT Sedimentation is a big problem in the sense of sustainability of surface water resource, especially in North Africa under the Mediterranean climate system. The counter measure to that problem is simply dredging but it has not been carried out in North African countries due to the financial reason. In this study, the present condition of sedimentation on the reservoir in Tunisia is reported and the practical countermeasure to that problem is suggested with regard to the possibility of using sediment as soil amelioration for alkaline saline soil which is very serious in North Africa.First, the bathymetric survey was carried out in order to grasp the development of sedimentation. And then, the water quality parameters were observed for the discussion of mass transfer in the water body. Finally, humic substances which can play a role of soil amelioration for saline alkaline soil are confirmed in the sediment sample.
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