Cold Hardiness Variation in Annual Medicago Species at the Seedling Stage

The study was carried out on three annual Medicago species (M. polymorpha, M. aculeata and M. ciliaris) each represented by five populations. Cold tolerance of the accessions was tested using a laboratory chilling test on seedling growth and soluble protein content of acclimated and non-acclimated seedlings. Lots of 3-d-old seedlings were submitted to cold treatment for 48 and 96 hours. For each treatment, response was determined by measuring seedlings’ weight and height, and radicle length for both acclimated and non-acclimated seedling lots. Seedling growth was adversely affected by low temperature, and resistant cultivars had a better rate of seedling growth than sensitive cultivars. M. aculeata genotypes were more resistant than those of M. polymorpha and M. sativa cv. Orca, and M. ciliaris populations were intermediate

Innovative Application of Scrap-tire Steel Cords in Concrete Mixes

More than 2.5 million scrap-tires are produced in Jordan each year. In addition, more than three million tires are currently stockpiled throughout the country. However, only one company has been established in the country for the recycling, recovery and reuse of scrap-tires. Currently, this industry is facing many challenges due to lack of support and subsidies from the government. Many researchers have investigated the use of recycled tire products in several traditional civil engineering materials. This research is exploring the use of steel cords, a by product of the tire recycling process, in concrete mixes. Different concrete specimens were fabricated and tested in uniaxial compression and splitting tensile strength. The steel cords were substituted into the concrete mix in volumetric percentages of 0% (control), 2%, 4%, 6%, 8% and 10%. Results show that mechanical properties of concrete made with steel cords are improved compared with concrete mix made with the traditional scrap-tires recycled material (such as crump rubber or rubber chips). Also, the test results show that even though the compressive strength is reduced when using steel cords, this reduction is minimal. When 2% of steel cords are used, there is an 18% increase in ductility. Moreover, splitting tensile tests show that concrete mixtures with any steel cords content have much greater toughness than the control mixture. This mechanical property mix indicates an excellent potential application of modified concrete mix in structures that absorb large amounts of energy. On the contrary, the density, air content and workability of the mixtures fabricated were not significantly affected

Influence des paramètres de composition sur le comportement du béton autoplaçant à l’état frais

La présente étude s’inscrit dans le cadre des travaux de recherche menés au département de génie civil de l'université de Mostaganem, en Algérie. Elle concerne l’étude de l’influence des paramètres de composition sur le comportement du béton autoplaçant à l'état frais. Elle a pour objectif de comprendre les rôles joués par les différents constituants susceptibles d’entrer dans la formulation d'un BAP à base de matériaux locaux notamment le sable de mer et le sable de carrière (considéré comme déchet naturel) et de mettre en évidence les éventuelles interactions entre constituants. Les résultats obtenus offrent de belles perspectives pour optimiser les BAP. Nos essais ont permis de développer une variété de formulations de béton autoplaçant répondant aux critères rhéologiques (bonne déformabilité, moins de ressuage, absence de ségrégation).Mots-clés : Béton autoplaçant, superplastifiant, fines calcaires, matériaux locaux, béton frais

Chemical diversity analysis of Tunisian Lawsonia inermis L. populations

Lawsonia inermis L. (commonly known as henna) is a cosmetic and medicinal plant cultivated from North-east Africa to India. The objective of this study was to evaluate the diversity of 25 L. inermis Tunisian populations, based on chemical markers. The populations were collected from the region of Gabès. The leaves and stems macro elements (Na, K, Ca, Mg and P) and trace elements (Cu, Zn, Fe and Mn) were analyzed for each population using spectrophotometry, and the nitrogen content was measured by Kjeldahl technique. The results showed that the leaves had a level of Ca, Na, P and K contents, ranging between 0.2 and 4%. Mg content was less than 0.2%, Cu, Zn and Fe contents were above 0.5, 1.1 and 15%, respectively, Mn content was less than 1.5% and nitrogen matter (NM) content was less than 1.5%. In the stems, P and K contents were respectively, above 5.12 and 0.5%, Mg content was less than 0.08%, Na and Ca contents were less than 0.2%, Cu, Zn, Fe and Mn contents were less than 0.95, 1.7, 4 and 0.5%, respectively and NM contents was less than 0.2%. However, the statistical analysis structured the populations based on the contents of their leaves and stems, in five groups.Key words: Lawsonia inermis, chemical diversity, macro elements, trace elements, nitrogen content

Jellyfish stings trigger gill disorders and increased mortality in farmed sparus aurata (linnaeus, 1758) in the mediterranean sea

Jellyfish are of particular concern for marine finfish aquaculture. In recent years repeated mass mortality episodes of farmed fish were caused by blooms of gelatinous cnidarian stingers, as a consequence of a wide range of hemolytic, cytotoxic, and neurotoxic properties of associated cnidocytes venoms. The mauve stinger jellyfish Pelagia noctiluca (Scyphozoa) has been identified as direct causative agent for several documented fish mortality events both in Northern Europe and the Mediterranean Sea aquaculture farms. We investigated the effects of P. noctiluca envenomations on the gilthead sea bream Sparus aurata by in vivo laboratory assays. Fish were incubated for 8 hours with jellyfish at 3 different densities in 300 l experimental tanks. Gill disorders were assessed by histological analyses and histopathological scoring of samples collected at time intervals from 3 hours to 4 weeks after initial exposure. Fish gills showed different extent and severity of gill lesions according to jellyfish density and incubation time, and long after the removal of jellyfish from tanks. Jellyfish envenomation elicits local and systemic inflammation reactions, histopathology and gill cell toxicity, with severe impacts on fish health. Altogether, these results shows P. noctiluca swarms may represent a high risk for Mediterranean finfish aquaculture farms, generating significant gill damage after only a few hours of contact with farmed S. aurata. Due to the growth of the aquaculture sector and the increased frequency of jellyfish blooms in the coastal waters, negative interactions between stinging jellyfish and farmed fish are likely to increase with the potential for significant economic losses

Distributed Cooperative Spectrum Sensing in Cognitive Radio Networks with Adaptive Detection Threshold

This paper proposes a cooperative sensing algorithm based on distributedfusion strategy and maintained probability of false alarm for cognitive radio. It furtherintroduces a reporting strategy that discusses how cooperative sensing in distributedmanner can select among possible candidates in order to reduce bandwidthrequirement. We adopted a dynamic distributed architecture for cooperative sensingbased on the link quality and found condition on the channel quality for cooperation tobe beneficial. Using probability of detection, and BER metrics we evaluated theperformance improvement of distributed cooperation over direct cooperation and noncooperativesensing. We used analytical formulation with possible candidate selectioncriteria to investigate and maximize the cooperation gain. By employing suchdistribution and selection technique, the reporting error due to the fading channel isreduced. Results show that the method effectively improve performance of sensing, itincrease the probability of detection up to 0.9 at <0.1 probability of false alarm.Sensitivity requirement is reduced with network scale and the number of nodesparticipate in decision fusion is reduced about 42% at probability of false alarm 0.1.ROC curve has obvious improvement compared with existing methods

BIOMECHANICAL STUDY ON CADAVER KNEE FOR THE EVALUATION OF CRUCIATE KNEE LIGAMENT RECONSTRUCTIONS

INTRODUCTION: Ruptures of the anterior and posterior cruciate knee ligament (ACL and PCL), alone or combined, are some of the most frequent joint injuries, especially in sports. The long-term unsatisfactory results and lack of systematic evaluation of surgical reconstructions have led us to undergo an evaluation on cadaver knees. MATERIAL AND METHOD: A preliminary study was performed on one cadaver knee. The femur was fixed on a holder and magnetic sensors “BirdsTM” were attached to the tibia and the femur, which tracked the knee’s movement. A threedimensional knee analyzer GENI(1) was used to calculate kinematic parameters (tibial internal and external rotation and ab/adduction), as well as ligament combined deformation (elongation / bending / torsion) during knee flexion. This experiment was performed on an intact knee and a knee where the PCL has been cut and reconstructed using a synthetic Trevia ligament. Finally the knee was dissected to produce a combined postero-lateral instability and reconstructed with and without postero-lateral corner reconstruction. The effect of different reconstruction methods on kinematics and ligament deformation were compared. RESULTS AND DISCUSSION: Kinematic parameters changed significantly when PCl and postero-lateral corner were dissected. The reconstruction of the PCL alone, using an “Over-the-Bottom” method described by Krudwig(2), shifted the curves back to the initial situation and decreased the variability of the movement. Ligament deformation was 3 mm elongation, 50o femoral flexion and 90o torsion. These values are in accordance with material properties and should lead to good long-term biofunctionnality. CONCLUSION: This study proposes an in vitro protocol for a better understanding of the clinical success or failure of different procedures. Preliminary results showed that the system and the protocol setup are sensitive to changes in kinematics following posterior cruciate ligament dissection and reconstruction. Experiments are performed at this time on several cadaver knees, in order to compare different reconstruction methods. REFERENCES: Sati, M. et al. (1997). Computer Assisted Knee Surgery: Diagnostics and Planning of Knee Surgery. Computer Aided Surgery 2, 108-123. Krudwig, W. (1997). In L'H. Yahia (Ed.), Ligaments and Ligamentoplasties. Heidelberg: Springer Verlag

Second T = 3/2 state in 9^9B and the isobaric multiplet mass equation

Recent high-precision mass measurements and shell model calculations~[Phys. Rev. Lett. {\bf 108}, 212501 (2012)] have challenged a longstanding explanation for the requirement of a cubic isobaric multiplet mass equation for the lowest $A = 9$ isospin quartet. The conclusions relied upon the choice of the excitation energy for the second $T = 3/2$ state in $^9$B, which had two conflicting measurements prior to this work. We remeasured the energy of the state using the $^9{\rm Be}(^3{\rm He},t)$ reaction and significantly disagree with the most recent measurement. Our result supports the contention that continuum coupling in the most proton-rich member of the quartet is not the predominant reason for the large cubic term required for $A = 9$ nuclei

Unfolding jellyfish bloom dynamics along the mediterranean basin by transnational citizen science initiatives

Science is addressing global societal challenges, and due to limitations in research financing, scientists are turning to the public at large to jointly tackle specific environmental issues. Citizens are therefore increasingly involved in monitoring programs, appointed as citizen scientists with potential to delivering key data at near to no cost to address environmental challenges, therein fostering scientific knowledge and advising policy- and decision-makers. One of the first and most successful examples of marine citizen science in the Mediterranean is represented by the integrative and collaborative implementation of several jellyfish-spotting campaigns in Italy, Spain, Malta, and Tunisia starting in 2009. Altogether, in terms of time coverage, geographic extent, and number of citizen records, these represent the most effective marine citizen science campaigns thus far implemented in the Mediterranean Sea. Here, we analyzed a collective database merging records over the above four countries, featuring more than 100,000 records containing almost 25,000 observations of jellyfish specimens collected over a period of 3 to 7 years (from 2009 to 2015) by citizen scientists participating in any of the national citizen science programs included in this analysis. Such a wide citizen science exercise demonstrates a valuable and cost-effective tool to understanding ecological drivers of jellyfish proliferation over the Western and Central Mediterranean basins, as well as a powerful contribution to developing tailored adaptation and management strategies; mitigating jellyfish impacts on human activities in coastal zones; and supporting implementation of marine spatial planning, Blue Growth, and conservation strategies