Showing papers by "Tunis University published in 2005"
TL;DR: This paper synthesises the existing methods applied to monitor P. oceanica meadows, identifies the most suitable techniques and suggests future research directions, and shows the interest of a practical guide that describes, in a standardized way, the most useful techniques enabling P. Oceanica meadow to be used as an environmental descriptor.
176 citations
TL;DR: In this article, the authors designed a model of InxGa1−xN tandem structure made of N successive p-n junctions going from two to six junctions for the less sophisticated structure to six for the most sophisticated.
122 citations
TL;DR: In this article, the Cretaceous deposits in central Tunisia blocks were studied by sequence stratigraphy, 2D seismic interpretation calibrated to the well and associated outcrop data, and constructing and comparing histories of the northern and southern blocks of the Gafsa master fault was the establishment of platform to basin stratigraphic configuration based on the major unconformity surfaces.
98 citations
TL;DR: This research and the data reported in the literature can confirm that P. pinea expresses no significant variability, and low genetic diversity revealed by fatty acid composition can be explained by anthropogenetic diffusion of genetically homogeneous reproductive material as early as the first explorations.
93 citations
TL;DR: In this article, the effects of KCl, NaCl and cysteine on the solubility in water of partially hydrolyzed wheat were studied at different pH values, and it was shown that the effect of such additives depends on solution pH.
92 citations
TL;DR: A survey of the main approaches to measuring poverty in its various dimensions is presented in this article to better understand the theoretical framework and the limitations of each one, highlighting the choice of which approach to adopt depending on the circumstances and the constraints of the study to be conducted.
Abstract: Recent pioneer papers of Sen (1981, 1985, 1992) have emphasized that poverty is a multidimensional issue. Hence, it should be seen in relation to the lack of important 'basic needs' or 'basic capabilities'. This recommendation has motivated many researchers to focus on the way multidimensional aspect of poverty should be measured and aggregated. This survey synthesizes the contribution of the main approaches to measuring poverty in its various dimensions to better understand the theoretical framework and the limitations of each one. This should highlight the choice of which approach to adopt depending on the circumstances and the constraints of the study to be conducted.
65 citations
TL;DR: The authors examined the influence of topic interest on the strength of different components of text representation and long-term retention according to the model of text processing by van Dijk and Kintsch (1983).
Abstract: The present work examined the influence of topic interest on the strength of different components of text representation and long-term retention according to the model of text processing by van Dijk and Kintsch (1983). A Series of relevant personality characteristics were assessed to control for alternative explanations of interest effect. A total of 286 8th, 9th, and 10th grade students was assigned to either a high topic interest or a low topic interest group. The participants had to read tow different texts (two weeks). Immediately afterwards, various process variables were assessed: Finally, participants weren given a recognition and verification tests, designed to assess the strength of the verbatim, propositional, and situational text representation. One Week after reading, students completed a recall rneasure: The interindividual finding with respect to the components of the representation of text revealed that the verbatim and the prepositional representation were not very predictable. The intraindividual analyses were more successful. The results were more consistent and interpretable with respect to the recall of text. It was shown quite clearly that the effects of interest are not only short-term. Most importantly, it could be shown that topic interest is related to text recall independently of other significant predictors.
55 citations
TL;DR: This study describes and compares the female gene pools of two neighboring Tunisian populations, Kesra (Berber) and Zriba (non-Berber), which have contrasting historical backgrounds and reveals that the emerging picture is complex, because ZribA would match the profile of a Berber Moroccan population, whereas Kesra, which shows twice the frequency of sub-Saharan lineages normally observed in northern coastal populations, would match a western Saharan population except for the low U6 frequency.
Abstract: North African populations are considered genetically closer to Eurasians than to sub-Saharans. However, they display a considerably high mtDNA heterogeneity among them, namely in the frequencies of the U6, East African, and sub-Saharan haplogroups. In this study, we describe and compare the female gene pools of two neighboring Tunisian populations, Kesra (Berber) and Zriba (non-Berber), which have contrasting historical backgrounds. Both populations presented lower diversity values than those observed for other North African populations, and they were the only populations not showing significant negative Fu's F(S) values. Kesra displayed a much higher proportion of typical sub-Saharan haplotypes (49%, including 4.2% of M1 haplogroup) than Zriba (8%). With respect to U6 sequences, frequencies were low (2% in Kesra and 8% in Zriba), and all belonged to the subhaplogroup U6a. An analysis of these data in the context of North Africa reveals that the emerging picture is complex, because Zriba would match the profile of a Berber Moroccan population, whereas Kesra, which shows twice the frequency of sub-Saharan lineages normally observed in northern coastal populations, would match a western Saharan population except for the low U6 frequency. The North African patchy mtDNA landscape has no parallel in other regions of the world and increasing the number of sampled populations has not been accompanied by any substantial increase in our understanding of its phylogeography. Available data up to now rely on sampling small, scattered populations, although they are carefully characterized in terms of their ethnic, linguistic, and historical backgrounds. It is therefore doubtful that this picture truly represents the complex historical demography of the region rather than being just the result of the type of samplings performed so far.
53 citations
TL;DR: In this article, a phase diagram of the TMTSF 2ClO4(1 − x)ReO4x solid solution in the limit of a low ReO4− substitution level (0 ≤ x ≤ 17%) has been revealed.
Abstract: The study of the anion ordered (TMTSF)2ClO4(1 − x)ReO4x solid solution in the limit of a low ReO4− substitution level (0 ≤ x ≤ 17%) has revealed a new and interesting phase diagram. Superconductivity is drastically suppressed as the effect of ReO4− non-magnetic point defects increases following the digamma behaviour for usual superconductors in the presence of paramagnetic impurities. Then, no long-range order can be stabilized above 0.1 K in a narrow window of substitution. Finally, an insulating SDW ground state in ReO4−-rich samples is rapidly stabilized with the decrease of the potential strength leading to the doubling of the transverse periodicity. This extensive study has shown that the superconducting order parameter must change its sign over the Fermi surface.
52 citations
TL;DR: In this article, a flat plate solar collector and a storage tank are used for domestic water heating in Tunisia, where the collector consists of a capillary exchanger integrated in a concrete matrix.
44 citations
TL;DR: Zouaghi et al. as mentioned in this paper investigated the limites paleogeographiques prefigurant l'archipel de Kasserine and correspondant a des couloirs de failles majeures N120 and N180 a intrusions saliferes triasiques, associees a d'autres failles decrochantes N90 and N60.
TL;DR: Feces voided by cattle treated with eprinomectin were associated with high larval mortality during the first 12 d after treatment, with null emergence until day 7, and the effects of eprinectin against the nontarget dung‐feeding Diptera Neomyia cornicina was assessed under laboratory conditions.
Abstract: The plasma and fecal concentrations ofeprinomectin weredetermined in cattlefollowing topical administrationat a dose rate of 0.5 mg kg−1. The maximum plasma concentrations of 12.24 ng ml−1 occurred 2 d after administration, and eprinomectin remained detectable in plasma 29 d after administration (0.10 ng ml−1). The maximum dung concentration of 350 ng g−1 was observed 3 d after administration and thereafter for at least 29 d (4 ng g−1). The amount of drug recovered in dung during this period was 20.50% ± 4.31% of the total administered dose. The effects of eprinomectin against the nontarget dung-feeding Diptera Neomyia cornicina was assessed under laboratory conditions. Feces voided by cattle treated with eprinomectin were associated with high larval mortality during the first 12 d after treatment, with null emergence until day 7. The no-observed-effect concentration for N. cornicina was estimated to be close to 7 ± 5 ng g−1.
TL;DR: From the structural investigations, it is found that the studied compound is built by infinite anionic ribbons parallel to the "a" axis, which form tunnels in which organic cations are inserted.
TL;DR: In this article, the authors considered the one-dimensional Hubbard model linear closed chains with various numbers of sites and obtained good results for the two-electron and high-density Fermi gas limits.
Abstract: Within the one-dimensional Hubbard model linear closed chains with various numbers of sites are considered in the self-consistent random phase approximation (SCRPA). Excellent results with a minimal numerical effort are obtained for $(2+4n)$-site cases, confirming earlier results with this theory for other models. However, the $4n$-site cases need further consideration. The SCRPA solves the two-site problem exactly. It therefore contains the two-electron and high-density Fermi gas limits correctly.
TL;DR: Results suggest regionally distinct phylogenetic units within an overall cohesive gene pool in the L. europaeus complex, supporting Petter's view that all North African hares belong to L. capensis except for one local population of savanna hares, and that cape hares and brown hares are conspecific.
Abstract: Tunisian hares (n = 45), currently assigned to Lepus capensis, were assayed for allelic variation at 40 allozyme loci, and allele frequencies at 32 loci were directly compared with earlier data of South African cape hares (L. capensis, n = 9) and European brown hares (L. europaeus, n = 244) to reveal genetic relationships among them. European mountain hares (L. timidus, n = 200) were used for outgroup comparison. In the Tunisian hares 27.5% of the loci were polymorphic with 2–4 alleles. Among all alleles at polymorphic loci, 15.1% occurred exclusively in Tunisian hares, 5.7% exclusively in cape hares, and 7.5% exclusively in brown hares at low frequencies. Not a single locus showed alternately fixed alleles between the samples of the L. capensis/L. europaeus complex. Levels of absolute and relative genetic differentiation among the samples of the L. capensis/ L. europaeus complex were low, relative to pairwise comparisons involving mountain hares. Diverse cluster analyses and multidimensional scaling of various pairwise genetic distance matrices concordantly grouped Tunisian hares with brown hares, and South African cape hares clustered only slightly farther apart, whereas mountain hares were distinctly separate. These results suggest regionally distinct phylogenetic units within an overall cohesive gene pool in the L. capensis/ L. europaeus complex, supporting Petter's view that all North African hares belong to L. capensis except for one local population of savanna hares, and that cape hares and brown hares are conspecific.
TL;DR: The characterization of the accessions belonging to different varieties was possi- ble, showing the power and efficiency of the molecular tools used.
Abstract: Introduction. Ficus carica L., well adapted to the Mediterranean climate, is ubi- quitous in Tunisia. In spite of the large possibilities of its adaptation to the Tunisian climate, its cultivation remains traditional. In Tunisia, this species is represented by a large number of varieties which are facing genetic erosion. To save these genetic resources, we studied some of the Tunisian varieties using molecular markers. The aim of this analysis was to study the genetic diversity of some cultivars and to characterize them. Materials and methods. Six microsatellites were used to characterize 16 cultivars (Ficus carica L.) belonging to two fig tree collections in the south of Tunisia. Results. The molecular markers used appeared highly polymorphic in common fig trees since 4-12 alleles per locus and a mean of heterozygoty of 0.656 were scored. The resolving power (Rp) of the six microsatellites tested ranged from 2.12 to 3.87 for the 16 cultivars studied, showing a significant genetic diversity (Ht = 0.762). Gene- tic differentiation between geographical groups was low (Gst = 0.032). The factorial corres- pondence analysis showed no well-defined relation between the 16 cultivars and their geographical origin. The genotype patterns allowed us to discriminate all of the cultivars. Conclusion. The characterization of the accessions belonging to different varieties was possi- ble, showing the power and efficiency of the molecular tools used. Tunisia / Ficus carica / genetic resources / identification / microsatellites / genetic markers
TL;DR: Using a new form of the 3G-Theorem for the Green function of a bounded domain Ω in this article, the authors introduced a new Kato class K(Ω) which contains properly the classical kato class Kn(ϵ) and exploited the properties of this new class, to extend some results about the existence of positive singular solutions of nonlinear differential equations.
Abstract: Using a new form of the 3G-Theorem for the Green function of a bounded domain Ω in \(\mathbb{R}^{n}\), we introduce a new Kato class K(Ω) which contains properly the classical Kato class Kn(Ω) Next, we exploit the properties of this new class, to extend some results about the existence of positive singular solutions of nonlinear differential equations
TL;DR: In this article, the authors present a method to analyze, monitor and control dynamic memory allocation in Java, which first performs pointer and escape analysis to detect memory scopes and then dynamically maps allocation places to the region stack at runtime via a registering mechanism.
TL;DR: The results of running 10 simulations for each experiment show that there is a reduction in malaria deaths not only when including schools, but in combination with increasing the number of hospitals.
Abstract: Malaria is a vector-borne disease that greatly affects social and economic development. We adopt the complex system paradigm in our analysis of the problem. Our aim is to assess the impact of education on malaria healthcare. Multi-agent systems are employed to model the spread of malaria in Haiti, where we introduce malaria education as a possible way of regulating deaths due to the parasite. We launch three experiments, each with environment modifications: three hospitals; three hospitals and 20 schools; and five hospitals and 20 schools. The results of running 10 simulations for each experiment show that there is a reduction in malaria deaths not only when including schools, but in combination with increasing the number of hospitals.
TL;DR: The 2 (1)Sigma(+) electronic state of SO(2+) received further treatment: in addition to vibrational bands due to the below barrier energy levels of this electronic state, at least nine continuum resonances were predicted which are responsible for the special shape of the spectrum in this energy region.
Abstract: Highly correlated ab initio methods were used in order to generate the potential energy curves of the electronic states of the SO2+ dication and of the electronic ground state of the neutral SO molecule These curves were used to predict the spectroscopic properties of this dication and to perform forward calculations of the double photoionization spectrum of SO In light of spin-orbit calculations, the metastability of this doubly charged ion is discussed: for instance, the rovibrational levels of the X (1)Sigma(+) and A (3)Sigma(+) states are found to present relatively long lifetimes In contrast, the other electronic excited states should predissociate to form S+ and O+ in their electronic ground states The simulated spectrum shows structures due to transitions between the v=0 vibrational level of SO (X (3)Sigma(-)) and the vibrational levels below the barrier maximum of 11 of the calculated electronic states The 2 (1)Sigma(+) electronic state of SO2+ received further treatment: in addition to vibrational bands due to the below barrier energy levels of this electronic state, at least nine continuum resonances were predicted which are responsible for the special shape of the spectrum in this energy region This work is predictive in nature and should stimulate future experimental investigations dealing with this dication (C) 2005 American Institute of Physics
TL;DR: In this article, the authors investigated the sedimentary organic matter (palynofacies and Rock-Eval) and the clay minerals content of Berriasian sediments of the Sidi Kralif Formation in central Tunisia.
Abstract: In order to precise the paleogeographic extension of the climatic variation known at the Jurassic/Cretaceous boundary, the sedimentary organic matter (palynofacies and Rock-Eval) and the clay minerals content of Berriasian sediments of the Sidi Kralif Formation are studied on the Jebel Meloussi section, central Tunisia Standard sedimentological and palynofacies analysis allow to reconstruct the bathymetric curve and the sequence stratigraphic scheme Using existing biostratigraphy based on calpionellids and ammonite zonation, the sequence stratigraphic interpretation can be correlated with the established eustatic chart Clay mineral assemblages are characterized by a shift in the kaolinite content, recorded at the end of the calpionellid zone B, at the early/middle Berriasian boundary, at a time of high long-term sea-level (MFS Be2, second order eustatic peak) A contemporary change in the clay mineral assemblages, interpreted as a climatic change, is known from the boreal area, and from the northern margin of the Tethys Sea That change is also documented southerly in southern Morocco (Agadir area), on the Atlantic domain A late Tithonian to early Berriasian dry and cooler phase is replaced by a middle to late Berriasian more humid phase, indicated by a general increase in kaolinite in the clay mineral assemblages The trend from a dry climatic phase to a more humid one, recorded on the boreal domain and along the northern margin of the Tethys is also recorded in lower paleolatitudes of Tunisia, on the southern margin of the Tethys, in better dated outcrops than the ones of Morocco The results obtained in Tunisia show that the beginning of the climatic change was precisely synchronous on both margins, and occurred within the same long-term high sea-level context
TL;DR: The great discriminative power of AFLP markers and their ability to represent genetic relationships among Hedysarum plants was demonstrated and evidence of a high degree of intra- and inter-population genetic diversity in H. coronarium was provided.
Abstract: Amplified fragment length polymorphism (AFLP) markers were used to characterize the genetic diversity within and among natural populations and cultivars of Hedysarum coronarium. Twelve populations within Tunisia were evaluated with three AFLP primer combinations. A total of 207 reproducible bands was detected of which 178 (86%) were polymorphic. The great discriminative power of AFLP markers and their ability to represent genetic relationships among Hedysarum plants was demonstrated. Genetic diversity within and among populations was assessed through Principal Component Analysis (PCA) and cluster analysis by using the Neighbor-joining clustering algorithm. AFLP technology has provided evidence of a high degree of intra- and inter-population genetic diversity in H. coronarium. AFLP banding patterns provided molecular markers correlated with the plants’ geotropism. In addition, AFLP markers can differentiate wild accessions from cultivars. Moreover, geographical origins did not correspond to population clustering.
TL;DR: In this paper, the potential energy functions (PEFs) of the bound electronic states of the SN− anion and the long-range parts of the PEFs of its excited states and their mutual spin-orbit couplings were derived.
Abstract: Highly correlated ab initio methods were used in order to generate the potential energy functions (PEFs) of the bound electronic states of the SN− anion and the long-range parts of the PEFs of its excited states and their mutual spin–orbit couplings. The SN (X2Π and a4Π) potential energy curves are also computed. In addition to the two bound electronic states of SN− (i.e. X3Σ− and 1Δ) already known, our calculations show that the 3Δ state is lying energetically below its quartet parent neutral state (a4Π). The depletion of the J = 3 component of SN−(3Δ) will mainly occur via weak interactions with the electron continuum wave. At large internuclear distances, SN−(5Π) state is predicted to possess a shallow polarization minimum supporting long-lived SN− ions. Finally, the reaction between S−(2Pu) and N(4Su) involves the electronic states of SN− and their mutual couplings, in competition with the autodetachment processes.
TL;DR: To determine the autolytic phenotype of five species in the Bacillus cereus group, the objective was to establish an experimental procedure and show clear results that unequivocally can be assigned as autolysis of Bacillus species.
Abstract: Aim: To determine the autolytic phenotype of five species in the Bacillus cereus group.
Methods and Results: The autolytic rate of 96 strains belonging to five species in the B. cereus group was examined under starvation conditions at pH 6, 6·5 and 8·5 in different buffers. The autolytic rate was strain-dependent with a wide variability at pH 6, but higher and more uniform at pH 6·5. At pH 8·5, and respect to the extent of autolysis at pH 6·5, it was relatively low for most of the strains with the lowest values between 13 and 52% in Bacillus mycoides and Bacillus pseudomycoides. Peptidoglycan hydrolase patterns evaluated by renaturing sodium dodecyl sulfate-polyacrylamide gel electrophoresis using cells of Bacillus thuringiensis ssp. tolworthi HD125 as an indicator, revealed complex profiles with lytic bands of about 90, 63, 46, 41, 38, 32, 28 and 25 kDa in B. cereus, B. thuringiensis and Bacillus weihenstephanensis. Bacillus mycoides and B. pseudomycoides had simpler profiles with lytic bands of 63, 46 and 38 kDa. Changes in the autolytic pattern were observed for cells harvested at the stationary phase of growth (72 h) showing an increase in the intensity of the 25 kDa band in the case of B. cereus, B. thuringiensis and B. weihenstephanensis, while no changes were observed for B. mycoides. Using Micrococcus lysodeicticus and Listeria monocytogenes as indicators lytic activity was retained by proteins of 63, 46, 38, 32 and 25 kDa and a new one of about 20 kDa in B. mycoides. Growth in the different media did not affect the autolytic pattern. NaCl abolished the activity of all the peptidoglycan hydrolases except for those of B. mycoides and B. weihenstephanensis. Lytic activity was retained in the presence of MgCl2, MnCl2 and EDTA and increased at basic pH.
Conclusions: Bacillus cereus/B. thuringiensis/B. weihenstephanensis showed a high extent of autolysis around neutral pH, even though they presented relatively complex autolysin profiles at alkaline pH. Bacillus mycoides/B. pseudomycoides had a higher extent of autolysis at acidic pH and a simpler autolysin pattern.
Significance and Impact of the Study: Information on the autolytic phenotype expand the phenotypic characterization of the different species in the B. cereus group.
TL;DR: In this paper, a 24-k ⋅ p model is used to compute the principal effective mass parameters at Γ, X and L valleys in a direct-band-gap semiconductor (GaAs) as well as an indirect-bandgap semiconducting (Si) using the Luttinger parameters and interband momentum matrix elements.
Abstract: A 24-k ⋅ p model is used to compute the principal effective-mass parameters at Γ, X and L valleys in a direct-band-gap semiconductor (GaAs) as well as an indirect-band-gap semiconductor (Si) The values of the effective masses for electrons, heavy holes and light holes in the Γ, X and L valleys are in very good agreement with those reported in other publications Satisfactory agreement with available experimental data is also obtained by this model The Luttinger parameters and interband momentum matrix elements proposed in this work are consistent with the previous publications
TL;DR: In this article, solid solutions of the Aurivillius-type compounds with Bi 4− x Ba x Ti 3− x Nb x O 12 formula were prepared by solid-state reaction of the constitutive oxides at optimised temperatures.
TL;DR: In this paper, a single-phase material from a mixture of V 2 O 5, 1,6-diaminohexane and H 2 O in the mol ratio 1:1:269 was synthesized.
Abstract: V 2 O 3 with spherical particles was hydrothermally synthesized (240 °C, 48 h, autogenous pressure) as a single-phase material from a mixture of V 2 O 5 , 1,6-diaminohexane and H 2 O in the mol ratio 1:1:269. It was characterized by scanning electronic microscopy, X-ray powder diffraction, thermal analysis and electron paramagnetic resonance.
TL;DR: Chakroun et al. as discussed by the authors discovered a cave rich in big mammalia remains, attributed to six species, composed at least of 12 individuals belonging to groups such as Equids, Rhinocerotids, Bovids, and Hystricids.
TL;DR: In this paper, a vector version of L p -multipliers for the Dunkl transform on R and the Littlewood-Paley operators were considered. And they were shown to be equal to L p −inequalities.
TL;DR: In this article, the density and refractive index coexistence curve data were analyzed to determine the critical exponent β for a binary fluid mixture with added (K +, Cl − ) ions at various concentrations.