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11.
In order to prevent surgical complications due to microbial infections, we have developed polypropylene suture grafted with silver nanoparticles (PPsuture/Ag nanocomposite) by a simple immersion procedure. Physical and mechanical properties of developed suture are investigated. Suture surface characteristics are examined by scanning electron microscopy (SEM) imaging and atomic force microscopy (AFM). Silver content on suture surface was determined by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). The mechanical properties of developed antibacterial PP suture/Ag were studied. We note that proposed silver coating method has not affected mechanical performances of suture. Antimicrobial performances of PP suture/Ag nanocomposites against S. aureus and E. coli colonies were also investigated. 相似文献
12.
Samia Gargouri Louis Bernier Mohamed Rabeh Hajlaoui Mohamed Marrakchi 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(8):807-815
The random amplified polymorphic DNA (RAPD) method was used to investigate the genetic variability and population structure of Fusarium culmorum isolated from wheat stem bases. A total of 108 isolates, representing seven geographically distinct populations, was collected from five climatic regions in Tunisia. Pseudo-allelic frequencies were estimated at each of the 25 putative RAPD loci analyzed by scoring for the presence or absence of amplified fragments; 92 haplotypes were found among the 108 strains. The analysis of the population structure did not reveal any trend with regard to geographic origin. Total gene diversity (HT
* = 0.318) was mostly attributable to diversity within populations (HS
* = 0.308). Analysis of molecular variance confirmed that most of the genetic variability was within populations. Genetic differentiation among populations was low to moderate (GST
* ranged from 0 to 0.190 and averaged 0.041 over all loci). Cluster analysis with UPGMA using genetic distances did not reveal any spatial clustering of the isolates collected from the different geographic regions. Based on these results, we conclude that the F. culmorum isolates recovered from different regions in Tunisia might be part of a single population pool. 相似文献
13.
Diogo S. M. Samia Eduardo Bessa Daniel T. Blumstein Jos A. C. C. Nunes Ernesto Azzurro Lorenzo Morroni Valerio Sbragaglia Fraser A. Januchowski‐Hartley Benjamin Geffroy 《Fish and Fisheries》2019,20(5):817-829
In an increasingly anthropic world, humans have profound impacts on the distribution and behaviour of marine fishes. The increased human presence has modified fishes’ antipredator behavioural responses, and consequently flight decisions, as a function of their changed perceptions of risk. Understanding how fish react to human presence can help identify the most vulnerable functional groups/species and estimate impacts caused by human disturbance. Shoal and body size are known to influence fish flight initiation distance (FID; the distance between the predator and prey when the prey begins to escape); however, few studies attempt to test the moderators of these relationships. Here, we present a comprehensive meta‐analysis evaluating FID of fish in response to human presence. Specifically, we investigated six candidate moderators that could influence the relationship between FID with shoal and body size. Our results showed that individual fish size was strongly and positively correlated with FID and the most important moderator that explained the variance in individual body size‐FID relationship was shoaling behaviour. However, and somehow surprisingly, we detected no significant relationship between shoal size and FID. We discuss how these results can inform the development of fish conservation strategies and ultimately assist in the management of marine protected areas. 相似文献
14.
Asma Ben Ghnaya Mohsen Hanana Ismail Amri Hazar Balti Samia Gargouri Bassem Jamoussi Lamia Hamrouni 《Journal of pest science》2013,86(3):571-577
The chemical composition of essential oil isolated by hydrodistillation from the leaves of Tunisian Eucalyptus erythrocorys Linn. was analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC/MS). Fifteen compounds were identified, representing 97 % of total oil, which was found to be rich in oxygenated monoterpenes (66.7 %), particularly in 1,8-cineole (54.8 %). The yield and the physico-chemical properties of oil were determined. The study of antifungal activity revealed that E. erythrocorys essential oil significantly inhibited the growth of five plant pathogenic fungi especially Bipolaris sorikiniana and Botritys cinerea. Moreover, herbicidal properties of the oil, tested on Sinapis arvensis L. and Phalaris canariensis L. indicated that the E. erythrocorys oil completely inhibited the seed germination at high concentration (1.5 μl/ml), while at low doses (0.25, 0.5, 0.75, 1 μl/ml) the oil acted by decreasing and delaying the germination and inhibiting the seedling growth of all tested weeds. 相似文献
15.
Mohamed Salem Carsten Heydel Amr El-Sayed Samia A. Ahmed Michael Zschöck George Baljer 《Tropical animal health and production》2013,45(2):351-366
Mycobacterium avium subspecies paratuberculosis is considered as one of the most serious problems affecting the world’s ruminant industry due to its significant impact on the global economy and the controversial issue that it may be pathogenic for humans. M. avium subspecies paratuberculosis is the causative agent of Johne’s disease in animals and might be implicated in cases of human Crohn’s disease. We provide an insight into M. avium subspecies paratuberculosis from some bacteriological, clinical, and molecular epidemiological perspectives. 相似文献
16.
Mohamed A. Radwan Samia A. A. Farrag Mahmoud M. Abu-Elamayem Nabila S. Ahmed 《Biology and Fertility of Soils》2012,48(4):463-468
Chitin has been chemically extracted from the Egyptian shrimp shell waste. The obtained chitin was transformed into the more
soluble chitosan. Chitin and chitosan were characterized using Fourier-transform infrared spectroscopy and proton nuclear
magnetic resonance spectrometry. These products were also characterized by their nematicidal potential against the root-knot
nematode, Meloidogyne incognita, infecting tomato in a glasshouse. Chitin or chitosan was incorporated into the soil at the rate of 1, 3, 5, and 10 g/kg,
and their nematicidal activity was compared with that of the synthetic nematicide oxamyl at the rate of 0.01 g a.i./kg. The
effects of the treatments on the growth of tomato were also examined. The obtained results show that chitin and chitosan reduced
tomato root galls and J2 of M. incognita in the soil in a dose-dependent manner. Chitosan was more effective in the reduction of galls and J2 in the soil than chitin. However, the efficacy of chitin and chitosan in reducing the number of J2 in the soil was less than that of oxamyl. As compared to the untreated inoculated plants, the length of shoots and roots
was significantly (p ≤ 0.05) increased in soil amended with either chitin or chitosan, whereas both treatments did not significantly (p > 0.05) differ with respect to the inoculated control on the effect on the dry weight of shoot and root systems. Furthermore,
neither chitin nor chitosan treatments at the tested rates were phytotoxic to tomato plants. 相似文献
17.
Samia Yahiaoui Alfonso Cuesta‐Marcos Maria P. Gracia Blanca Medina José M. Lasa Ana M. Casas Francisco J. Ciudad José L. Montoya Marian Moralejo José L. Molina‐Cano Ernesto Igartua 《Plant Breeding》2014,133(2):218-226
Barley landraces from the western Mediterranean area have not been thoroughly exploited by modern breeding. This study aims at assessing the agronomic value of a core collection of lines derived from landraces of Spanish origin and to compare them with sets of successful old and modern cultivars. The agronomic performance of a set of 175 barley genotypes, comprising 159 landrace‐derived lines and 26 cultivars, was evaluated in a series of 10 field trials, carried out over 3 years and several locations. The most relevant trait of the landraces was higher grain yield at low production sites than cultivars, which may be related with better ability to fill the grain under stressful conditions. On the other hand, lateness, excessive plant height and lodging were negative traits frequently found in the landraces. Large genotype‐by‐environment interaction (GEI) for grain yield was detected, related partly with differences between germplasm groups, probably indicating local adaptation. GEI was also associated with the interaction of heading time and powdery mildew resistance with temperature. 相似文献
18.
Photosynthesis is an important process for plants in which plants utilize the energy from sunlight to manufacture and produce all their own food. Although UV-C damage is not physiologically relevant for plants growing in the sun, short-wavelength (UV-C) radiation from germicidal lamps has been used to study cell damage in animals as well as in plants. This study provides a review of the effects of a methanolic extract of spinach (SE) as a natural powerful antioxidants used at two concentrations (25 and 50?ppm) on fenugreek seedlings grown under UV-C stress conditions. The results revealed that exposure of fenugreek seedlings to low UV-C period (30?min) increased growth criteria of the produced seedlings. In addition, the contents of chlorophyll, total pigments, total protein, free amino acids, non-enzymatic (carotenoids, total phenol, flavonoids, α?tocopherol & ascorbic acid contents) and enzymatic antioxidants were increased at this period. By increasing exposure periods of UV-C radiation, the growth criteria and chemical constitutes of the seedlings were decreased. Application of lower concentration of SE (25?ppm) improve the growth of the seedlings at 30-min UV-C and was able to protect seedlings from high periods of UV-C irradiation by increasing all measured parameters except CAT. These increases might be an adaptive mechanism to minimize the adverse effects of longer exposure of UV-C radiation. Moreover, treating the irradiated seedlings with spinach extract led to an obvious alteration in gene expression including synthesis of some proteins bands and disappearance of other protein sets of the protein profile. 相似文献
19.
Nourhen Mnasri Cynda Chennaoui Samia Gargouri Ridha Mhamdi Kamel Hessini Salem Elkahoui Naceur Djébali 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(3):501-515
Sixty two rhizospheric and endophytic bacterial strains were evaluated for their biocontrol effect on two aggressive Fusarium culmorum isolates (Fc2 and Fc3). We observed that 35 % and 23 % of the tested strains inhibited the in vitro growth of Fc2 and Fc3 respectively. The observed antagonism was due to inhibition by contact (13–19 % of the strains) or at distance (10–16 % of the strains) for both fungal isolates. Some of the antagonistic bacteria showed the ability to produce diffuse and/or volatile compounds that inhibit the growth, the sporulation and macroconidia germination of F. culmorum. None of the tested antagonistic bacteria showed chitinase activity on synthetic medium. The sequencing of the 16S rDNA genes of some antagonistic bacteria showed that they belong to the genera Bacillus, Pseudomonas and Microbacterium. The double inoculation of durum wheat seeds by the antagonistic bacterial strains (B13, B18, BSE1, BSE3 and B16E) and the two F. culmorum isolates showed that germination and seedling vigor were generally improved in vitro. The percentage of infected seeds was also reduced. In greenhouse trials, the biocontrol effectiveness of F. culmorum was dependant from the virulence of the fungal strain and the specificity of the antagonistic interaction between bacterial and fungal strains. The bacterial strains B18 and B16E reduced F. culmorum infection on durum wheat plants probably due to their antagonistic and plant growth promoting activities and they may be used in a mixture as seed biopriming inoculum for plant growth bio-promoting and Fusarium wheat diseases biocontrol. 相似文献
20.
Samia S CORTéS 《干旱区科学》2020,12(5):717-729
The replacement of native dry forests by commercial (exotic) tree plantations could generate changes in rainfall partitioning, which further affects the water cycle. In this study, we determined (i) the rainfall partitioning into interception, throughfall and stemflow, (ii) the role of rainfall event size on rainfall partitioning, (iii) the pH of water channelized as throughfall and stemflow, and (iv) the runoff in Lithraea molleoides (a native species) and Pinus elliottii (an exotic species) stands in the dry Chaco mountain forests, central Argentina. On average, interception, throughfall and stemflow accounted for 19.3%, 79.5% and 1.2% of the gross rainfall in L. molleoides stand, and 32.6%, 66.7% and 0.7% of the gross rainfall in P. elliottii stand, respectively. Amounts of interception, throughfall and stemflow presented positive linear relationships with the increment of rainfall event size for both tree species (P<0.01 in all cases). Percentages of interception, throughfall and stemflow were all related to the increment of rainfall event size, showing different patterns. With increasing rainfall event size, interception exponentially decreased, throughfall asymptotically increased and stemflow linearly increased. Both P. elliottii and L. molleoides stands presented significant differences in the pH values of water channelized as throughfall (6.3 vs. 6.7, respectively; P<0.01) and stemflow (4.5 vs. 5.8, respectively; P<0.01). Runoff occupied only 0.3% of the gross rainfall in P. elliottii stand and was zero in L. molleoides stand. Our results showed that the native species L. molleoides presented 13.6% more water reaching the topsoil (i.e., net rainfall; net rainfall=gross rainfall-interception-runoff) than the exotic species P. elliottii. This study improves our understanding of the effects of native vegetation replacement on the local water balance in the dry forest ecosystems. 相似文献