The objective of this study is to analyze the prospective of the low water flows of the N'zo-Sassandra River located in the West of Ivory Coast. The hydroclimatic data used (rainfall, ETP, flow) extend on the one hand over the historical period (1961-2017) and on the other hand over the future period 2071-2100 (CORDEX data). The methodological approach adopted is based on the analysis of past low flows, the climate prospective analysis and the hydrological prospective analysis. The hydrological impact variable used is the annual minimum monthly mean flow (MAMF). Thus, a pessimistic climate forecast scenario was used (RCP 8.5.). This climate scenario was then fed into a rainfall-runoff hydrological model (GR2M model) calibrated to the 1961-1990 reference period and validated over the 1991-2017 period. In response to the climate forcing, future monthly low-flow rates (MAMF) were simulated. An increase in the number of flows in the class ]0-4] m3/s was observed, reflecting low flows in the 2071–2100-time frame. The best statistical law retained following the frequency analysis of the low-water flows is the lognormal law. By 2071-2100, a decrease in rainfall (-19.2%) and an increase in temperature (+3.9°C) are predicted in the N'zo-Sassandra watershed. Frequent low-water flows estimated from the lognormal law have shown a bias of -50.38%, which translates into a decrease of half of the frequent low-water flows by the end of the 21st century compared to the current period. This decrease in flows will have consequences on the availability of water resources for irrigation, fishing, breeding, drinking water supply, navigation, etc. This is why we propose as alternative resources for agricultural needs, groundwater which is less impacted by global changes.
This work consists in studying the productive and reproductive performance of Holstein dairy cows (n=77) reared in an intensive production system in a Mediterranean climate, as well as the factors of their variations. Meteorological data collected between 2017 and 2020 for the region of Beja, North-West of Tunisia, revealed that the average monthly values of ambient temperature (Ta), relative humidity (HR) and temperature-humidity index (THI), are respectively 19.97 ±1.24°C, 73.69±3.42%, and 66±1.74. During the 3 years of study, the cows were exposed to a hot summer season which began in Jun (THI= 76) and persisted until September (THI =77). On average, milk production at 305 days of lactation, milk fat (MG) and protein (MP) content, as well as somatic cell count (SCC) were respectively 5782 ± 358 Kg, 3.36 ± 1.65%, 3.12 ± 0.42% and 489 ± 305 x 103 cells/ml. Several factors significantly (P < 0.05) affect milk production. Indeed, the highest milk production is observed during the year 2020. When the THI increases, the drop of milk production is greater (-0.18kg/d, per THI point). Multiparous cows produce more milk than primiparous cows, with higher yields at peak lactation (30.0 kg/d) and a lower persistence coefficient (95.6%). Cows calved in winter produced more milk (+22%; P<0.05) than cows calved in summer. The interval between calving to the first insemination (IV-IA1), calving to fertilizing insemination (IV-IAF) and calving interval (IVV) were 87.4 ± 28.2 days, 134 ± 71 days and 425 ±75 days respectively. The success rate in 1st insemination (TRIA1) and three or more insemination, as well as number of inseminations per conception were respectively 29.1±18.5%, 9.7±5.5% and 2.11±1.6. In conclusion, control of breeding conduct, in particular the heat detection technique, is essential to improve the productivity of the Holstein cow raised in an intensive production system in a hot Tunisian climate.
Medicinal plants produced many secondary metabolites which constituted an important source of bioactive molecules. This study aims to determine organic extracts (EOs) antioxidant activity extracted from terminal branches of Pistacia lentiscus (P. lentiscus) collected at three different phenological stages (vegetative, flowering and fructification). For this, different extracts were prepared by maceration in various solvents with increasing polarity notably diethyl ether, ethyl acetate, dichloromethane, methanol and water. Antioxidant activity was reported by DPPH free radical scavenging, iron reducing capacity and total antioxidant capacity tests. Results showed that phenological stages and solvent polarities affected significantly P. lentiscus antioxidant activity. Furthermore, aqueous and methanolic extracts from vegetative stage present the highest total polyphenols, total flavonoids and condensed tannins contents. Methanolic extract from vegetative stage exhibited the greatest antioxidant activity and even exceeded that of synthetic antioxidants BHT and ascorbic acid. In this study, P. lentiscus represents an important source of antioxidant molecules. As a result, extracts of this plant could replace synthetic antioxidants in e food, pharmaceutical and cosmetic fields.
Currently, herbal medicine has proven its effectiveness and undeniable benefits in our daily lives, confirming that plants can prevent and treat. In this context, we are interested in carrying out an ethno-pharmacological survey on the traditional use of Melissa officinalis in the Tabarka region as well as phytochemical screening and the study of antioxidant and antibacterial activities. The survey conducted in the Tabarka region revealed that lemon balm was used in traditional medicine to treat a whole range of pathologies. Indeed, we have shown that Melissa officinalis is traditionally used for the treatment of various diseases and particularly those of the digestive system pathologies and nervous disorders. The survey also revealed three methods of preparation: decoction, infusion and maceration. The method of administration is highly dependent on the pathology to be treated. In the present work, the phytochemical screening showed that Melissa officinalis leaves aqueous extract (MOAE) presents an important scavenging action against the DPPH radical. Importantly, MOAE presented a broad spectrum of antibacterial activity and Gram +ve were more sensitive than Gram-ve bacteria. Thus, the bioactive components of lemon balm can be used as antioxidant and antibacterial substances.
The objective of this work is to carry out a comparative study between irrigated and rain-fed olive farms in arid area, Zarzis belonging to Southern Tunisia. In order to achieve this objective, a survey was carried out on nearly 30 farms: 13 are in the irrigated lands and 17 are in dry areas. As a first step, we proceeded through a socio-economic, technical and environmental assessment in order to determine the characteristics of each type of farms. As a second part, we tried to identify the strengths, weaknesses, opportunities and threats specific to the olive sector in this arid region, through SWOT method. The assessment shows that the irrigated farms were the object of modernization process, whose owners are really investors, aiming a rapid profitability by this farming activity. The farms are characterized by a high density of olive tree plantations and the stability of yields. Thus, they represent a source of employment in the region. On the other side, dry olive farms have a classic production system and low yields, generating not only a problem of profitability, but also of the viability of these farms, which explains the abandonment of these lands.
The aim of this study is to identify the impact of a sea-land breeze circulation on the ventilation of air masses over the Mediterranean Tunisian coast (Boukornine area) during the summer period. Our results show the Mediterranean Sea has an important effect on the chemical characteristics of atmospheric aerosols by the advection of particles from the sea to the coastal site. Indeed, the daytime sea breeze as well the nighttime land breeze limit the ventilation of air masses by the redistribution of aerosols. Besides, it was found that higher concentrations of sodium, chlorine and sulfur over the examined area are associated with the sea-land breeze recirculation while the crustal constituents stay practically constant with some fluctuations due to local effect. The contribution of sea-breeze in Boukornine area was more important than those recorded in other sites in Tunisia. This study proves the high influence of topography which increases the effect of sea-breeze.
Multiplicative adjustment factors for month of calving, age at calving and lactation length were computed for complete lactation records (n= 11’175) recorded between 2012 and 2017 from 6251 dairy cattle raised in 33 Holstein dairy herds. An animal model was used with fixed effects for herd-year-sector, month of calving and age at calving and random and the residual random error. The objectives of this study were: 1) to examine the effect of the non-genetic factors on the milk yield production, 2) to adjust milk yield for non-genetic sources of variation and 3) to examine the effect of milk yield adjustments on estimates of the genetic trend. Main results showed that month of calving, age at calving and lactation length were significant sources of variation for milk yield. Cows calving in the fall and early winter yielded 430 kg and 455 kg more milk than cows calving in spring and summer, respectively. Holsteins in Tunisia reached their maximum milk yield between 68 and 70 months of age. Average adjusted milk yield for days in milk, month and age of calving was 6621±2883 kg. An overall rate of increase in milk yield was found to be 22.68 kg/year over the 15 years period.
In order to estimate some equations of daily milk production from linear body measurements of 85 local lacting goats were used in the present study. The morphostructural parameters included body length, withers height, heart girth and hip height, the body weight and the daily milk were recorded weekly from from the 7th postpartum day up to the end of lactation period. Four models were tested to estimate daily milk from some body measurements. A high correlation between daily milk and all linear body measurements was obtained. A significant correlation (p<0.05) were obtained between all linear body measurements and daily milk yield. The high value of correlation was presented between body weight and the daily milk (r=0.66). A estimates equation with coefficient of determination (44%) has been got to estimate daily milk with (R2). The daily milk of local goat could be estimated from linear body measurements and it could be use the goats' body weight and withers height as a good measurements to predict daily milk with reasonable R2
The roots of Chrysopogon zizanioides (L.) Roberty, belonging to the Poaceae family, are the main source of volatile that has substantial value in perfume, cosmetics, pharmaceutical and food industries. The study of C. zizanioides volatiles, obtained from plant roots cultivated in Tunisia, using GC and GC/MS revealed that more than 50 compounds were detected of which 14 constituents were identified representing 33.87% of the total. Oleic acid (17.09%) and (E) -3-Eicosene (7.77%) were the major components at the species level. However, 10,13 methyl ester octadecadienoic acid (0.01%), (Z) - 9,17-octadecadienal (0.01%), (Dimethylethyl-1,1) Bis-2,6 Methyl- 4 Phenol (0.04%), methyl pentadecanoic acid, 13-methyl-, methyl ester (0.05%), (Z) -13-octadecenal (0.06%) and linoleic acid ethyl ester (0 , 06%) are the constituents which have the lowest contents.
The accumulation of organic pollutants, pesticides, fertilizers, etc. causing critical health trouble to humans, animals, many aquatic ecosystems, and plants. This study evaluated the elimination of the pesticides as pentachlorophenol (PCP: 800 mg L−1) by bioaugmentation process in sterile secondary treated wastewater (STWW) and mineral salt medium (MSM). Also, the impact of surfactant addition (sodium dodecyl sulfate ‘SDS’ and Cetyltrimethylammonium bromide ‘CTAB’) in PCP elimination phenomena. The PCP rate in different treatments was analyzed by high-performance liquid chromatography (HPLC). The bacteria biomass was measured through a spectroscopy approach at 600 nm optical density (OD600). The chloride rates were determinate through the calorimetric approach. In addition, the STWW disinfection was released through the UV radiation technique. The HPLC analysis confirmed that the strain P. mosseli HM627603 and P. putida HM627611 were able to tolerate and remove respectively 99.6 and 76.12% of PCP (800 mg. L-1). The chloride rates increased after 7 days in all treatments with a value of 0.64 to 3.12 g L-1 for P. mosseli HM627603 in MSM. The SDS surfactant induces an increase in the PCP elimination from STWW through P. putida HM627611. The bacterial inactivation became quicker within 80 seconds in sterile STWW supplemented with PCP at 800 mg L-1 for P. putida HM627611 tested in agar medium.
The purpose of this investigation was to assess the nodulation and the plant growth of white lupin (Lupinus albus L.) in Tunisian soils. For this, two L. albus varieties, Mekna (Tunisian) and Lumen (French), were cultivated in soils sampled from 56 locations without a history of lupin cultivation or rhizobial inoculation. All soils were analyzed for their physical and chemical proprieties. At harvest, nodulation and plant growth parameters were recorded for both varieties. The results showed that 75% of soils were alkaline and calcareous. Nodulation was often poor, suggesting the absence of host-specific rhizobia. It was absent in 41 soils, abundant in 2 (Sejnen and Mraissa), and scarce but efficient in the remaining 13 soils. Furthermore, white lupin varieties have different responses to native nodulating bacteria since the local variety, Mekna, developed significantly more root nodules and in more soils than the imported variety. Growth parameters and nitrogen accumulation were also measured as indicators of nitrogen fixation efficiency. Considerable variability was detected among soils. It was found that the imported variety, Lumen, showed high sensitivity to the soil active lime content compared to Mekna. Interestingly, high biomass production and nitrogen accumulation were recorded in soils originating from Madian, Tejerouin, Benouria, and Oued zinga, with a high active lime content ranging from 26% to 31%. This finding suggested that white lupin can be cultivated in Tunisian calcareous soils, especially the most promising local variety, Mekna. Isolation and the selection of efficient bacteria from alkaline calcareous soils are necessary to promote the development of this valuable legume in Tunisia.
