Effect of mechanical consolidation on adhesion mechanism of hybrid non-woven Alfa fibers reinforced unsaturated polyester composite

Vibrational analysis based on FTIR measurements were performed on hybrid non-woven Alfa fibers reinforced unsaturated polyester composite (HNWAFRUP) and its constituents. The reinforcement was made up of Alfa and wool fibers in the relative volume fractions ratio 4:1. These non-woven fibers sheet were consolidated mechanically by means of the needle punching. This study revealed that the increase of passages numbers in this device allowed the separation of the Alfa fibers and the reduction of the lignins component in these fibers which decreased its hydrophilic character. Chemical reactions between wool and Alfa fibers were based mainly on the appearance of new vibrations originating from wool fibers in the reinforcement. Adhesion mechanism between the matrix and the reinforcement was established by chemical bonds formed by secondary bonding. Tensile testing performed on this composite revealed the enhancement of its mechanical properties attributed to a less fiber to fiber contact of wool fibers. Nevertheless, the decrease of its specific Youngs modulus revealed the mechanical consolidation effect on Alfa fibers/matrix adhesion

Sterol composition of caper (Capparis spinosa) seeds

Caper is a perennial shrub of the Mediterranean Basin. The most important economical species is Capparis spinosa. Sterols of C. spinosa seed oil isolated from seven Tunisian stands were identified andquantified. C. spinosa contained  high levels of phytosterols (2240.4 mg/kg of total extracted lipids), of which -sitosterol, with 1390 mg/kg, was the most abundant (57.53%). Campesterol and stigmasterol accounted for 382 and 265 mg/kg, respectively (17.05 and 11.85% of the total sterols, respectively). C. spinosa seed oil also contained a high level of 5-avenasterol (6%). We detect also brassicasterol (3.39 mg/kg). Cholesterol and campestanol are detected in much lower levels. These results bring attention to the richness of C.spinosa seed oil with sterols which are the most important class of the minor components

Prevalence and risk factors of low back pain among undergraduate students of a sports and physical education institute in Tunisia

Introduction: For obvious reasons, athletes are at greater risk of sustaining a lumber (lower) spine injury due to physical activity. To our knowledge, no previous studies have examined the prevalence of low back pain (LBP) in a Tunisian sports and physical education institute.Aim: To assess the prevalence of LBP in different sports among students studying in a sports and physical education institute in Tunisia, to determine the causes of the injuries, and to propose solutions.Methods: A total of 3,379 boys and 2,579 girls were studied. A retrospective cross-sectional survey was conducted on a group of students aged 18.524.5 years at the Higher Institute of Sport and Physical Education of Sfax to estimate the prevalence of LBP and its relation to the type of sports. Data on age, weight, height, smoking, and the sport in which the student was injured in the low back were collected from the institute health service records from 2005 until 2013.Results: LBP was reported by 879 of the 5,958 study participants (14.8%). The prevalence of LBP was significantly higher (pB0.001) in females (17.6%) than in males (12.5%). LBP prevalence did not differ by body mass index or smoking habit (p0.05). The sports associated with the higher rates of LBP were gymnastics, judo, handball, and volleyball, followed by basketball and athletics.Conclusion: LBP is frequent among undergraduate students of a sports and physical education institute in Tunisia. It is strongly associated with fatigue after the long periods of training in different sports. Gymnastics, judo, handball, and volleyball were identified as high-risk sports for causing LBP.Keywords: low back pain; sports students; sports training; risk factor

First report of <i>Pseudocercospora cladosporioides</i>, the causal agent of Cercospora leaf spot of olive trees, in Tunisia

Olive trees (Olea europaea) cv. Meski having leaves with yellow spots on the upper surface and grey blotches on the lower surface were found in three orchards located in the regions of Takelsa, Testour and Enfidha, central and northern Tunisia. The shoots of the olive trees had also become defoliated indicating a severe attack of a pathogen. Pseudocercospora cladosporioides was isolated from symptomatic leaves and Koch’s postulates were fulfilled. This is the first Tunisian report of P. cladosporioides causing Cercospora leaf spot of olive trees

Natural genetic variation in Calligonum Tunisian genus analyzed by RAPD markers

The Calligonum genus is one of the most economically important resources of the Tunisian desert, playing an important role in the lives of desert local population. A great range of genetic diversity could be seen in diverse populations of this genus which are spread all over Tunisian areas. DNA-based molecular markers are playing increasingly important role in the analysis of genetic diversity in wide range of plants. This study is an attempt to collect, compile and collate information on the existing natural genetic diversity, at intra-specific and inter-populational levels in Calligonum genus (C.azel, C.arich and C.comosum). This study deals with 16 genotypes of Calligonum (Polygonaceae) collected from different regions of Tunisian desert using random amplified polymorphic DNA (RAPD) marker. In total, 46 polymorphic bands amplified by 4 random primers, with the polymorphic rate of 89.06% were recorded. The commercial software package SPSS 16 was used to develop similar matrices based on the Dice coefficient which is defined as 2a/2a+u, where “a” is the number of positive matches and “u” is the number of non-matches. From the analysis, it is imperative that predominantly obligate out breeding behavior of Calligonum genus, helps these diverse accessions to spread and occupy specific geographical niches in the Tunisian arid regions.Key words: Calligonum, genetic diversity, Inter-specific variation, RAPD marker, Tunisian desert

‘Chemlali Mhassen’: New olive cultivar derived from crossbreeding program in Tunisia with high oil quality and productivity

The new olive cultivar ‘Chemlali Mhassen’ was derived from the autopollination of the Tunisian oil cultivar ‘Chemlali Sfax’. The main morphological differences between the two cultivars were observed on the endocarp (symmetry, position of maximum diameter, apex, base and surface). On the agronomic plan, this cultivar is distinguishable from the original cultivar due to its medium earliness of bearing (4 years), medium alternate bearing (0.44), early ripening, moderate sensitivity to verticillium and its high olive production per tree (7.7 kg). Concerning oil quality, ‘Chemlali Mhassen’ had higher performances than the original cultivar for oleic acid content (70 to 77 %) and lower contents for palmitic acid (9.2 to 11.5 %) and linoleic acid (9.3 to 14.7 %). Similar performances were recorded between the new and the original cultivars for rhizogenesis behavior and pollen compatibility

Lung function profiles and aerobic capacity of adult cigarette and hookah smokers after 12 weeks intermittent training

Introduction: Pulmonary function is compromised in most smokers. Yet it is unknown whether exercise training improves pulmonary function and aerobic capacity in cigarette and hookah smokers and whether these smokers respond in a similar way as do non-smokers.Aim: To evaluate the effects of an interval exercise training program on pulmonary function and aerobic capacity in cigarette and hookah smokers.Methods: Twelve cigarette smokers, 10 hookah smokers, and 11 non-smokers participated in our exercise program. All subjects performed 30 min of interval exercise (2 min of work followed by 1 min of rest) three times a week for 12 weeks at an intensity estimated at 70% of the subject’s maximum aerobic capacity (VO2max). Pulmonary function was measured using spirometry, and maximum aerobic capacity was assessed by maximal exercise testing on a treadmill before the beginning and at the end of the exercise training program.Results: As expected, prior to the exercise intervention, the cigarette and hookah smokers had significantly lower pulmonary function than the non-smokers. The 12-week exercise training program did not significantly affect lung function as assessed by spirometry in the non-smoker group. However, it significantly increased both forced expiratory volume in 1 second and peak expiratory flow (PEF) in the cigarette smoker group, and PEF in the hookah smoker group. Our training program had its most notable impact on the cardiopulmonary system of smokers. In the non-smoker and cigarette smoker groups, the training program significantly improved VO2max (4.4 and 4.7%, respectively), v VO2max (6.7 and 5.6%, respectively), and the recovery index (7.9 and 10.5%, respectively).Conclusions: After 12 weeks of interval training program, the increase of VO2max and the decrease of recovery index and resting heart rate in the smoking subjects indicated better exercise tolerance. Although the intermittent training program altered pulmonary function only partially, both aerobic capacity and life quality were improved. Intermittent training should be advised in the clinical setting for subjects with adverse health behaviors.Keywords: cigarette smokers; hookah smokers; pulmonary function; aerobic capacity; interval trainin