Mediterranean Weather Conditions Research Articles

Application of first-order kinetic removal models on constructed wetlands under Mediterranean climatic conditions

The objective of the study was to verify the applicability of P-k-C* model to evaluate the treatment response of horizontal CWs (H-CWs) and to assess key design parameters for the model optimization in Mediterranean climate conditions. The experimental study was carried out in 4H-CWs located in the province of Catania (Eastern Sicily, Italy). The parameters P, kA20 and θ were optimized to minimize the sum of the square of the errors (SSE) between observed and modeled outlet concentrations for COD, BOD5 and NO−3 quality parameters. Once the minimization process was carried out by an iterative, nonlinear procedure, then data were divided into calibration and validation sets for each CW. The calibration was set by fixing a P value from the literature range and varying kA20 and θ and then by using the obtained values of kA20 and θ and by varying P. This procedure was repeated until two successive P calibrated values differed less than 2%. The performance of the model was very good in most of the cases, as also evaluated in terms of R2, NSE and RMSE. In particular, considering the three investigated pollutants, the calculated kA20 values were generally higher than those from CWs located in temperate climate zone (65–157.1 m year−1), while the θ values were slightly lower than 1 (0.88–0.91). This study can be considered a first contribute for P-k-C* model application in semi-arid regions characterized by Mediterranean weather conditions.

AN ANALYSIS OF FACTORS INFLUENCING THE QUALITY OF HOUSING CONSTRUCTION PROJECTS IN THE WESTERN CAPE, SOUTH AFRICA

Quality measurement is the trigger for quality improvement; things that cannot be measured therefore can be improved. The result of poor quality in the house hold construction projects in the Western Cape hence might be the lack of quality measurement methods or standards. The research intended to provide clients, building inspectors, building inspectors, project managers, designers and contractors with the necessary information needed to better manage the quality of house hold construction projects in the Western Cape Province. Factors that affect the quality of house hold construction projects during the construction phase were identified. The use of hybrid was implemented in order to exhaust all possible ways to obtain data and questionnaires were developed and used as research tools to obtain the opinions of respondents that included the contractors, building inspectors, household and project managers, on the factors affecting construction projects and how these factors can methodology be addressed to ensure the construction of quality buildings. It was concluded that the most important factors affecting the quality of house hold constructions projects are, the skills and experience of contractors and project managers, site lay-outs, materials, equipment used, Mediterranean weather conditions, lead time in decision making. Therefore the authors recommend that the construction industry should have a stand-alone board that deals with quality standards and controls the quality standards of buildings by taking into considerations the factors identified and also this board should behavior have rights to demolish buildings that are not up to standard. Article DOI: http://dx.doi.org/10.20319/mijst.2016.s11.195211 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Increased Difficulties to Control Late Blight in Tunisia Are Caused by a Genetically Diverse Phytophthora infestans Population Next to the Clonal Lineage NA-01.

In Tunisia, late blight caused by Phytophthora infestans is a serious threat to potato and tomato. The Mediterranean weather conditions can be conducive to infection in all seasons and the host crops, tomato and potato, are grown year round. Potato is planted and harvested in two to four overlapping intervals from August to June and tomato is grown both in open fields and in greenhouses. The consequences of these agricultural practices and the massive import of seed potato on the genetic variation of P. infestans are largely unknown. We conducted a survey in which 165 P. infestans isolates, collected from five subregions in Tunisia between 2006 and 2008, on which we studied genotypic diversity through nuclear (simple-sequence repeat [SSR]) markers and combined this with a previous study on their mitochondrial haplotypes (mtDNA). The phylogenetic analysis revealed the presence of a major clonal lineage (NA-01, A1 mating type, mitochondrial haplotype Ia). Isolates belonging to this clonal lineage were found in all regions and showed a relatively simple virulence pattern on a potato differential set carrying different Solanum demissum resistance genes. Apart from isolates belonging to this NA-01 clonal lineage, a group of isolates was found that showed a high genetic diversity, comprising both mating types and a more complex race structure that was found in the regions where late blight on potato was more difficult to control. The population on potato and tomato seems to be under different selection pressures. Isolates collected from tomato showed a low genetic diversity even though potato isolates collected simultaneously from the same location showed a high genetic diversity. Based on the SSR profile comparison, we could demonstrate that the four major clonal lineages found in the Netherlands and also in other European countries could not be found in Tunisia. Despite the massive import of potato seed from Europe, the P. infestans population in Tunisia was found to be clearly distinct.

Irrigation return flow and nitrate leaching under different crops and irrigation methods in Western Mediterranean weather conditions

Agriculture constitutes a major source of non-point pollution (e.g., nitrates) where overall water resources are affected, in particular, aquifers. Intensive agricultural practices take place in regions with appropriate weather conditions that are usually deficient in water resources. The preservation of water resources in these types of regions depends on the evaluation of the efficiency of agricultural practices for specific crops and conditions. Although water scarcity is a characteristic feature in the Western Mediterranean, it is one of the most appropriate regions in the world for intensive agriculture development for climatic reasons. In the current work, percolation and N leaching from different crops (corn, potato, and rotation of lettuce and melon) under different irrigation methods (surface, sprinkler and drip) were evaluated through experimental plots. Water (irrigation+precipitation) and fertilizer inputs were accurately controlled. Soil water content and nitrate concentration were monitored from time domain reflectometry measurements, and cup lysimeters and destructive sampling, respectively. Percolation and nitrate leaching was simulated from different numerical codes (STICS and GLEAMS, tipping bucket method; HYDRUS-1D, Richards’ equation), which were chosen based on the available information and the specific purposes of each experiment. For the studied periods, the obtained results showed high percolation values: 34, 58 and 37% of total applied water for corn, potato, and rotation of lettuce and melon, respectively. Also, high N leaching values across all experiences were observed, even higher than the applied doses in some periods as consequence of remobilizing mineralized N, despite following the recommended agricultural management practices. Percolation and N leaching were mostly controlled by the precipitation regime, namely, unevenly distributed intensive rainfall events, mainly in autumn and spring, which have a great impact in irrigated agriculture due to the permanent high soil water content. In detail, irrigation water applied for frost prevention on potato crops and plastic cover for melon crops, played a very important role for both percolation and N leaching. Whilst for the corn crop, N leaching mainly took place in the fallow period (autumn and winter), where the rain leached N present in soil from previous crops.

Mediterranean Weather Conditions and Exacerbations of Multiple Sclerosis

Background: Previous studies provide increasing support for the impact of environmental factors on disease incidence and activity in multiple sclerosis (MS). Objectives: The purpose of this research was to assess the relationship between the incidence of MS relapses and weather conditions in Israel. Methods: Clinical data, including occurrence of relapses in 235 patients, during 3 consecutive years (2001–2003) were assessed against the general daily meteorological variables. Initially, the relationship between the relapses and their mode of distribution was evaluated. Second, the relationship between the number of relapses on a specific date and the meteorological variables was assessed. Third, the tendency to seasonality in the occurrence of relapses was examined. Results: No significant correlation was found between the number of relapses and a specific season, month or day. Moreover, no clear relationship was found between certain meteorological variables or a combination of variables and the frequency of the relapses. Conclusion: The meteorological parameters studied were not found to have a significant impact on the occurrence of relapses in this group of patients. These findings raise questions regarding the clinical significance of the impact of weather conditions, at least in the context of the Mediterranean climate, on the disease course of patients with MS.

Lipophilic Antioxidants and Some Carpometric Characteristics of Fruits of Ten Processing Tomato Varieties, Grown in Different Climatic Conditions

Microclimatic conditions and fruit maturity can affect the health-promoting compounds in tomato fruits. The aim of this study was to evaluate the influence of Mediterranean and continental weather conditions, on fruit firmness and coloration as well as on the concentrations of lycopene, alpha- and beta-carotene and lutein and on alpha-, delta- and gamma-tocopherol, in fruits of 10 processing tomato varieties. Compositional data analysis was carried out in order to determine the composition of carotenoids and tocopherols. Mediterranean weather conditions associated with agricultural practice have contributed to faster fruit ripening, which significantly improved the coloration with all varieties, and significantly increased the concentration of total carotenoids and lycopene with varieties with oval and elongated fruits. Environmental conditions in a low tunnel increased the red coloration, but did not significantly increase the content of either total carotenoids or tocopherols. The cultivar and the location of cultivation had a strong effect on the composition of the analyzed lipophilic antioxidants.

Adaptation of a functional model of grassland to simulate the behaviour of irrigated grasslands under a Mediterranean climate: The Crau case

In order to take into account firstly the specificities of Mediterranean weather conditions on grass growth and secondly the effect of irrigation management on hay, we adapted an already published model of grassland growth. From literature new equations were added to account for water balance, botanical composition and the effect of wind. The modified model was parameterised based on new experimental data. An automatic and rigorous parameter estimation procedure was developed based on a criterion that combines the goodness-of-fit for dry matter (DM), leaf area index (LAI) and fraction of total transpirable soil water (FTSW). Mean squared error of prediction (MSEP) was estimated using cross-validation. Adding the three equations for water balance, botanical composition and wind effect improved the goodness-of-fit of the model. A sensitivity analysis showed that the model results were mainly sensitive to the parameter that controls the increase of leaf area index and to the radiation use efficiency coefficient. Both absolute values and dynamics of DM, LAI and FTSW were well simulated and satisfactory for future use of the model in a decision support tool. Estimated MSEP values for DM, LAI and FTSW were 0.145 T ha −1, 0.092 m 2 m −2 and 0.0155% respectively.

Epiphytic fitness of a biological control agent of fire blight in apple and pear orchards under Mediterranean weather conditions

The behaviour of Pseudomonas fluorescens EPS62e was investigated in apple and pear orchards under Mediterranean climatic conditions. The trials studied the influence of weather conditions, plant host species, presence of indigenous microbial community and spread from treated to nontreated trees on colonization and survival. Population dynamics were assessed by real-time PCR and CFU-counting methods. With inoculated flowers, weather conditions were optimal for colonization, and EPS62e established high and stable population levels around 10(8) CFU per organ, according to both methods of analysis. The plant host species did not influence the colonization rate, and the biocontrol agent dominated the microbial communities of blossoms, representing up to 100% of the total cultivable population. With inoculated leaves, the EPS62e population decreased to nondetectable levels 30 days after treatment according to both methods used. EPS62e spread moderately in the orchard, being detected in nontreated flowers of trees 15-35 m from the inoculation site. The combined use of real-time PCR and CFU-counting methods of analysis permitted the identification of three physiological states for EPS62e in the field, which consisted of active colonization, survival and entry into a viable but nonculturable state, and cell death.

Modelling and performances of a deep-freezing process using low-grade solar heat

A solar deep-freezing process has been designed. It aims at cooling down a cold box to about −20 °C, using simple flat plate solar collectors operating at 70 °C. This original process involves two cascaded thermochemical systems based on the BaCl 2/ammonia reaction. Its working mode is discontinuous as it alternates between a regeneration mode during daytime and a cold production mode during nighttime. A global dynamic model involving the various system components allows the simulation of the process; it predicts the evolution of the components temperatures and the rates of chemical reactions of the system. It also allows the dimensioning of the system components to maintain a 500 l cold box at −20 °C during the 6 sunniest months of the year under typical Mediterranean weather conditions and provide over 80% of the total yearly cooling needs of this box. This requires a solar collector area of 5.8 m 2 and 39 kg of reactive salt. The predicted coefficient of performance (COP) is about 0.1 over the year, and the net solar COP, taking into account the collector efficiencies, is 0.05.

OPTIMIZATION OF NOCTURNAL CLIMATE MANAGEMENT IN PE-GREENHOUSES IN CYPRUS

OPTIMIZATION OF NOCTURNAL CLIMATE MANAGEMENT IN PE-GREENHOUSES IN CYPRUS

Ecophysiological and Agronomic Response of Tempranillo Grapevines to Four Training Systems

Four grapevine training systems (single curtain, vertical shoot-positioned, high bush, and short bush) were compared for their effects on physiological performance, yield, vegetative growth, and must composition in <i>Vitis vinifera</i> L. cv. Tempranillo in Mediterranean weather conditions. Net CO₂ assimilation rate, stomatal conductance, and transpiration rate were measured at the beginning of bunch closure, veraison, and maturity on fully exposed leaves. At each stage, changes in these values were measured in the morning, at midday, and in the afternoon. Differences in individual leaf responses among treatments were the result of photosynthetically active radiation levels on the outer leaves. Fully exposed leaves of the bush-trained vines had the highest stomatal conductance and transpiration rates and those of the high-bush vines had the highest photosynthetic rates. Grape yield results showed that the vertical shoot-positioned system was the most productive, adjusted for its greater pruning level. Although acceptable grape quality was obtained with all four systems, single curtain and high bush had greater total soluble solids at the expense of lower grape yield.

Influence de la marée sur la qualité des eaux du bas Sebou soumis aux rejets de la plaine du Gharb (Maroc)

Demographic, industrial and agricultural development of Morocco during the last few years have often altered water quality. The Gharb district and particularly the Sebou river basin are among the most heavily polluted regions in Morocco. Oued Sebou collecting basin is 40,000 km 2, situated in north-western Morocco. Its water flows from the north-western slopes of the Middle Atlas range to the Atlantic Ocean. Its tributaries collect waters from the Rif range (Oued Ouerrha) and from central Morocco (Oued Beht). It is the main purveyor of water of the Gharb plain, a major agricultural region in Morocco, where fertilizers and pesticides are widely used. Along its banks, various industries (paper mills, sugar plants, tanneries, food industries, wool mills, chemical plants, etc.) have settled and contribute to the development of large towns which are not equipped with facilities for the treatment of either industrial or domestic waters. It is a real example of water pollution in a developing country. In order to assess the actual water quality of lower Sebou and to monitor both the effect of the release of pollutants and the influence of other factors, a wide pluridisciplinary research program on the biological, ecotoxicological and microbiological situation is in progress. Eleven stations have been selected: one on Oued Ouerrha (S1), one on Oued Beht (S6), one on Oued R'dom (S5) and eight on Oued Sebou, distributed along about 230 km (Fig. 1). The following paper reports on the physico-chemical quality of surface waters of lower Sebou, submitted to domestic, agricultural and industrial pollution and to tidal movements. Samples were analyzed for 17 parameters following AFNOR norms; 5 were determined on site (temperature, oxygen, pH, conductivity and salt content) while the others (DBO, DCO, MES, NH + 4, NO − 2, NO − 3, Cl 2− 4, SO 2− 4, PO 2− 4, Ca 2+, total hardness and alkalinity) were determined in the laboratory. Temperature does not vary significantly between different stations. Suspended matters levels were mainly dependent on hydrologic sequences of the rivers (low or high waters) and showed a wide range of seasonal changes. Because of decantation, the levels decreased from upstream to downstream, but after Kénitra, they increased again, because of solid wastes from the town and of a strong bottom tidal flow that pulls out deposited solid matter. Organic pollution is severe. Means of BOD 5 vary from 19 to 76 mg/L and of COD from 39 to 180 mg/L. They can reach 135 mg/L for BOD 5 and 834 mg/L for COD. The worst situation is found downstream to Sidi Allal Tazi sugar plant. For dissolved oxygen, the lowest levels were found downstream to the town of Sidi Slimane (22%) and to Sidi Allal Tazi sugar plant (38%). Ammonium was mostly low (0–0.09 mg/L) while at downstream stations (8, 9, 10, 11) there was a small increase, as well as at S6 (downstream to Sidi Slimane town). The presence of ammonium nitrogen is usually considered as figuring an uncompleted degradation of organic matter (Rodier, 1984). Nitrites followed the variations of ammonium. Nitrates showed a wide range of variations, possibly because of strong turbulence enhancing locally the oxygenation. In order to determine which were the main parameters that drove the ecosystem dynamics, a main components analysis was performed on the matrix given by the results of 8 campaigns at 11 sampling stations. The results are given in Table 1 and Fig. 5. It appears that tidal movements, and thus salt levels, are main factors upstream to Kénitra and downstream to Sidi Allal Tazi. The tidal phenomenon has been specifically studied (Fig. 5D and E). The confrontation of fresh and sea water in the Sebou mouth gives birth to a physical stopper which prevents polluted water from reaching the ocean and thus slows the improvement of water quality. Oued Sebou gives a good example under Mediterranean weather conditions of a severe pollution due to hydrochemical conditions strongly influenced by municipal and industrial wastes. Most of the physico-chemical parameters are higher than the values given by Nisbet and Verneaux (1970). Moreover, downstream, tidal influence contributes to further damage water quality. Efforts should be made to reduce toxic substances release in the Gharb plain.

Phosphorus leaching in sandy soils .II. Laboratory studies of the long-term effects of the phosphorus source

Long-term phosphorus (P) losses and gains in sandy soils continuously fertilized with either ordinary superphosphate or coastal superphosphate (a granulated mixture of superphosphate, rock phosphate and elemental sulfur) or previously fertilized with superphosphate were investigated under leaching conditions in columns in the laboratory. The soils were subjected to 10 consecutive cycles designed to simulate the mediterranean weather conditions in the Harvey region of the Coastal Plain of Western Australia. Each cycle consisted of a wet phase during which the equivalent of 850 mm of rainfall was leached through the soil and a drier phase during which the soil was incubated in the presence of moisture equivalent to summer rainfall (150 mm). Dissolved inorganic P in the leachate was used as a measure of P loss. A sequential fractionation procedure (a resin extraction followed by 0.5 M sodium bicarbonate, 0.1 M sodium hydroxide and 0.1 M sulfuric acid extractions) and total inorganic and organic P were used to measure changes in P levels in the soils. Phosphorus losses from the previously fertilized soils decreased logarithmically with increasing number of cycles. Total inorganic P and resin-extractable P were able to explain &gt;94% of the variation in P losses. Addition of either fertilizer increased the amount of P leached from the soil and 10-40% more P was leached by adding superphosphate rather than coastal superphosphate. The percentage of the cumulative P lost by leaching decreased with increasing application rate of both fertilizers when expressed as a percentage of the cumulative water plus citrate-soluble P added. Addition of either fertilizer increased the amount of acid-extractable P, but coastal superphosphate had a much greater effect than superphosphate. Leaching losses of P were influenced by fertilizer solubility in the short term (&lt; 1 year). In the long term, however, the water plus citrate-insoluble P in the fertilizers also contributed to P losses by leaching.