A genetic and molecular analysis of flowering time in Arabidopsis thaliana using natural variation = Een genetische en moleculaire analyse van bloeitijd in Arabidopsis thaliana gebruikmakend van natuurlijke variatie

The natural allelic variation at flowering time loci between two Arabidopsis thaliana accessions; Landsberg erecta (L er ) and the tropical Cape Verde Island (Cvi) has been analyzed. Quantitative trait locus (QTL) mapping in recombinant inbred lines (RILs) grown under three environments, differing in day-length and/or vernalization treatment, was used to detect and locate flowering loci on the genetic map of Arabidopsis. Four main QTLs were identified, designated EDI , FLF , FLG and FLH , to which most of the flowering time differences could be attributed. At the EDI and FLH loci, Cvi alleles resulted in earliness, whereas at FLF and FLG , Cvi alleles caused lateness. Among these QTL, EDI ( EARLY, DAY-LENGTH INSENSITIVE ) is the main locus responsible for day-length sensitivity. To determine the molecular basis of this natural genetic variation, we have isolated the EDI locus using a map-based cloning strategy. The positional cloning of the EDI QTL showed it to be a novel allele of CRY2 , encoding the blue-light photoreceptor cryptochrome-2, that has previously been shown to promote flowering in long-day photoperiods. It was shown that the unique flowering phenotype in the CRY2 -Cvi allele results from a single amino acid substitution that reduces the down-regulation of the CRY2 protein in plants grown under short photoperiods, leading to early flowering. The genetic interaction between CRY2 and other loci involved in the different flowering promotion pathways was studied. The three different types of CRY2 alleles ( CRY2 -Cvi = EDI , CRY2 -L er , and the CRY2 null mutant fha1-1 ) were combined with the mutants representing the different flowering pathways. This analysis indicated that the so called "vernalization and autonomous pathway" that control FLC ( Flowering locus C ) expression, repress the expression of CRY2

NANO-SPONGE NOVEL DRUG DELIVERY SYSTEM AS CARRIER OF ANTI-HYPERTENSIVE DRUG

Objective: The study was designed to prepare Nano-sponge formulation loaded with nifedipine. Studying parameters which affecting the formulas in addition to pharmacokinetics and toxicity tests. Methods: Nine Nano-sponge formulations were prepared by the solvent evaporation technique. Different ratios of polymer ethylcellulose, CO-polymers β-cyclodextrin and hydroxypropyl β-cyclodextrin in addition to solubilizing agent polyvinyl alcohol were used. Thermal analysis, X-ray powder diffraction (XRPD), shape and surface morphology, particle size, %production yield, %porosity, % swelling, and % drug entrapment efficiency of Nano-sponge were examined. Release kinetic also studied beside comparison of pharmacokinetic parameters of the optimum choice formula and marketed one in addition to Toxicological consideration. Results: Particle size in the range of 119.1 nm to 529 nm which were increased due to the increase in the concentration of polymer to the drug. Nano-sponge revealed porous, spherical nature. Increased in the drug/polymer molar ratios (1:1 to 1:3) may increase their % production yield ranged from 62.1% to 92.4%. The drug content of different formulations was in the range of 77.9% to 94.7%, and entrapment efficiency was in the range of 82.72 % to 96.63%. Drug released in controlled sustained pattern and followed Higuchi, s diffusion mechanism. Pharmacokinetic parameters of optimized formula showed significant higher maximum plasma drug concentration, area under plasma concentration-time curve, volume of distribution and mean residence time. Nano-sponge loaded drug proved biological safety at low concentrations. Conclusion: Nano-sponge drug delivery system has showed small Nano size, porous with controlled drug release and significant-high plasma drug concentration that improved solubility, drug bioavailability and proved safety

CHITOSAN NANOPARTICLES AS DRUG DELIVERY SYSTEM FOR CEPHALEXIN AND ITS ANTIMICROBIAL ACTIVITY AGAINST MULTIIDRUG RESISTENT BACTERIA

Objective: The evolution of antimicrobial resistance is a universal obstacle that necessities the innovation of more effective and safe antimicrobial alternatives with synergistic properties. The purpose of this study was to investigate the possible improvement of cephalexin antimicrobial treatments by loading into chitosan-based nanoparticles, then evaluate their antibacterial and antibiofilm activities as well as determination of its cytotoxicity. Methods: Chitosan nanoparticles (CSNPs) were prepared by ionic gelation method. Parameters were studied to optimize the particle size of CSNPs including pH, stirring rate, homogenization and ultra-sonication time. Size was measured by transmission electron microscope (TEM) and Zeta sizer, morphology seen by scanning electron microscope (SEM). Entrapment efficiency, drug loading and drug content were calculated. Stability of both plain and loaded chitosan Nano-carriers, Drug release and Kinetics also compatibilities were studied. Antimicrobial activity of CSNPs and cephalexin loaded CSNPs were evaluated against 4 Gram-positive and 4 Gram-negative standard and clinical isolates by microdilution method, also assessment of antibiofilm activity of both formulas was investigated against two biofilm producers clinical isolates by tube assay in addition to determination of their cytotoxicity by MTT(3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Results: Chitosan nanoparticles and its loaded antibiotics proved compatible combination with small Zeta size, suitable Zeta potential, maximum EE% and drug-loading capacity, sustained controlled release properties followed diffusion kinetic model and six month stability studies. Cephalexin loaded CSNPs showed better antimicrobial activity than plain CSNPs. Synergistic effects were found against S. aureus (ATCC 25923), B. subtilis (ATCC 9372), S. epidermidis, E. faecalis, P. aeruginosa (ATCC 29853) in addition to two carbapenem resistant isolates k. pneumoniae and E. coli. Also cephalexin loaded CSNPs exhibited antibiofilm activity against E. faecalis clinical isolate. Even though, cephalexin loaded CSNPs exhibited significant antibacterial activity, it showed less toxicity against mammalian cells, it had IC50 equal to 231.893 and did not exhibit any cytotoxicity against the WI-38 fibroblast cells at concentration 23.4 µg/ml. Conclusion: Cephalexin loaded CSNPs possessed good stability and sustained release effect in addition to its antimicrobial, antibiofilm activities and reduced cytotoxicity

Bridging GPS Outages Using Spectral Fusion and Neural Network Models in Support of Multibeam Hydrography

In classical hydrographic surveying, the use of GPS is limited to providing horizontal control for survey vessels. More recently, an alternative practice has evolved, which determines depth values relative to a geodetic datum and then relate them to tidal datums through a series of vertical datum transformations. Although it has a number of advantages over classical hydrographic surveying, this practice requires accurate 3D positioning information. Unfortunately, accurate 3D positioning solution may not always be available as a result of communication link problems, GPS outages, or unsuccessful fixing for the ambiguity parameters. This paper examines the use of wavelet analysis to spectrally combine the GPS/INS height data series and the heave signal to bridge the height data gaps. In addition, a neural network-based model is developed to precisely predict the horizontal component of the survey vessel.En los levantamientos hidrográficos clásicos, el uso del GPS está limitado al suministro de control horizontal para los buques hidrográficos. Más recientemente, se ha desarrollado una práctica alterna-tiva, que determina los valores de la profundidad relativos a un datum geodésico y los relaciona pos-teriormente con los datums de mareas a través de una serie de transformaciones del datum vertical. Aunque tiene una serie de ventajas con respecto a los levantamientos hidrográficos clásicos, esta práctica requiere una información precisa del posicionamiento en 3D. Desgraciadamente, puede que una solución de posicionamiento preciso en 3D no esté siempre disponible como resultado de los problemas de enlaces de datos, los cortes GPS, o un ajuste infructuoso de parámetros de ambigüedad. Este artículo examina el uso de un análisis de ondas pequeñas para combinar espectralmente la serie de datos de altura GPS/INS y la señal de oleaje para superar las deficiencias de datos de alturas. Además, se ha desarrollado un modelo basado en la red neural para predecir con precisión la compo-nente horizontal del buque hidrográfico.Dans les levés hydrographiques classiques, l‘utilisation du GPS est limitée à la fourniture d‘un contrôle horizontal pour les bâtiments hydrographiques. Plus récemment, une autre pratique est ap-parue et celle-ci détermine les valeurs de profondeur par rapport à un système géodésique puis les rapporte au niveau de référence des marées par le biais d‘une série de transformations du système géodésique vertical. Bien que ceci offre un certain nombre d‘avantages par rapport aux levés hydro-graphiques classiques, cette pratique nécessite des informations exactes sur la détermination de la position en 3D. Malheureusement, une solution exacte de détermination de la position en 3D n‘est pas toujours disponible à cause de problèmes de liaison en matière de communications, de défaillan-ces GPS, ou de réparation infructueuse des paramètres d‘ambiguïté. Le présent article examine l‘uti-lisation d‘une analyse des ondelettes pour combiner de manière spectrale les séries de données de hauteur GPS/INS et le signal de pilonnement afin de combler les lacunes en données de hauteur. En outre, un modèle inspiré d‘un réseau neuronal est en cours de développement en vue d‘une prédic-tion précise de la composante horizontale du bâtiment hydrographique

Pleural manometry in pleural effusion

AbstractPleural manometry is a valuable tool to determine lung expansibility and helps to avoid unsafe pressure changes during thoracentesis.Study designCross-sectional descriptive study.Aim of the workTo measure the pleural pressure during thoracocentesis in patients with pleural effusion and the value of their measurement in both diagnostic and therapeutic decisions.Patients and methodsForty-four patients with pleural effusion were included. Thoracocentesis was performed for all patients. End-expiratory pleural pressure values were recorded after the withdrawal of 5ml of fluid (initial pleural pressure), after the removal of every 500ml for the first liter then after the withdrawal of every 250ml for the second liter, and every 100ml thereafter until the procedure completed. The last recorded pressure was used as the closing pressure. Comparisons were done according to the etiology and character of the effusion (transudate or exudate). The pressure/volume curves were done and studied.ResultsTwenty out of 34 patients with exudative pleural effusion having a pleural space elastance >14.5 cm H2O/L were identified. These patients had a diagnosis of malignant effusion either primary or secondary (14/20 patients), or inflammatory causes (6/20 patients). All the 10 patients with transudative effusion had an elastance <14.5 cm H2O/L. The study revealed a statistically significant decrease in closing pressure in the symptomatic group when compared to non-symptomatic group (p value=0.022), none of our patients (including symptomatic patients) had exceeded the proposed cutoff value for unsafe pleural pressures (−20cm H2O).ConclusionPleural manometry is proved a useful tool to differentiate freely expandable lungs from lungs with entrapment. It is proved as a useful guide as to when to terminate thoracentesis in large volume thoracentesis

S3TC: Spiking Separated Spatial and Temporal Convolutions with Unsupervised STDP-based Learning for Action Recognition

Video analysis is a major computer vision task that has received a lot of attention in recent years. The current state-of-the-art performance for video analysis is achieved with Deep Neural Networks (DNNs) that have high computational costs and need large amounts of labeled data for training. Spiking Neural Networks (SNNs) have significantly lower computational costs (thousands of times) than regular non-spiking networks when implemented on neuromorphic hardware. They have been used for video analysis with methods like 3D Convolutional Spiking Neural Networks (3D CSNNs). However, these networks have a significantly larger number of parameters compared with spiking 2D CSNN. This, not only increases the computational costs, but also makes these networks more difficult to implement with neuromorphic hardware. In this work, we use CSNNs trained in an unsupervised manner with the Spike Timing-Dependent Plasticity (STDP) rule, and we introduce, for the first time, Spiking Separated Spatial and Temporal Convolutions (S3TCs) for the sake of reducing the number of parameters required for video analysis. This unsupervised learning has the advantage of not needing large amounts of labeled data for training. Factorizing a single spatio-temporal spiking convolution into a spatial and a temporal spiking convolution decreases the number of parameters of the network. We test our network with the KTH, Weizmann, and IXMAS datasets, and we show that S3TCs successfully extract spatio-temporal information from videos, while increasing the output spiking activity, and outperforming spiking 3D convolutions

Désaromatisation oxygénante asymétrique de phénols à l'aide d'iodanes pour la synthèse totale de substances naturelles

The oxygenative phenol dearomatization reaction is a very useful transformation, as a key step in the synthesis of complex natural substances. It gives access to cyclohexa-2,4-dienones from ortho-substituted phenols, through the use of hypervalent iodine reagents (i.e., iodanes), which constitutes a modern alternative to toxic heavy-metal-based reagents (e.g., Pb, Tl, Hg). Our team is interested in the hydroxylative dearomatization of 2-alkylphenols (HPD reaction) by iodanes, a transformation that results in the formation of one quaternary stereogenic center. Control of the absolute configuration of this chiral center through the use of an appropriate substrate or reagent is amongst our goals. Chiral iodanes recently developed in the laboratory allowed us to reach enantiomeric excesses above 90 % in model HPD reactions. Successful application of these chiral iodanes led us to achieve the first total syntheses of (–)-bacchopetiolone and (+)-maytenone, as well as that of the epoxy ortho- quinol polar head of (+)-scyphostatine.La réaction de désaromatisation oxygénante de phénols est une transformation très utile en tant qu’étape clé dans la synthèse de substances naturelles complexes. Elle permet de préparer des intermédiaires de type cyclohexa-2,4-diénones à partir de phénols ortho-substitués, notamment en utilisant des réactifs iodés hypervalents (i.e., iodanes) qui constituent une alternative moderne aux réactifs à base de métaux lourds toxiques (e.g., Pb, Tl, Hg). Notre équipe s’intéresse plus particulièrement à la désaromatisation hydroxylante de 2-alkylphénols (réaction HPD) par des iodanes, transformation qui engendre la création d’un centre carboné quaternaire stéréogène. Le contrôle de la configuration de ce centre chiral par l’utilisation d’un substrat ou d’un réactif approprié est un de nos objectifs. Des iodanes chiraux récemment développés au laboratoire ont permis d’atteindre des excès énantiomériques de plus de 90% dans des réactions HPD modèles. Nous avons exploité avec succès ces iodanes chiraux pour réaliser les premières synthèses totales de la (–)-bacchopétiolone et de la (+)-mayténone, ainsi que pour élaborer la tête polaire de type ortho-quinol époxydé de la (+)-scyphostatine

Une lecture écocritique du roman Le Règne du vivant d’Alice Ferney

Le Règne du vivant d’Alice Ferney est un plaidoyer écologique et un cri de révolte et de dénonciation contre la pêche illicite et le braconnage en haute mer, inspiré de l’action du militant écologiste Paul Watson. La présente contribution met en évidence l’imaginaire écologique dans ce « roman-documentaire engagé » qui porte une réflexion sur le déclin et la dégradation de la biodiversité marine. Une lecture écocritique de ce texte va nous permettre de voir comment la question du monde naturel est abordée dans la fiction et comment la dégradation de notre environnement nous responsabilise pour la préservation de notre planète. L’approche choisie constitue une perspective méthodologique pour étudier et analyser les choix éthiques, esthétiques et émotionnels adoptés par l’auteure pour étaler un imaginaire écologique. Nous allons donc montrer comment Le Règne du vivant lève le voile sur certaines pratiques nettement abusives en portant une réflexion sur la menace de la biodiversité marine et les enjeux de la disparition des grands mammifères marins. Nous allons également expliquer les implications formelles de l’auteure en vue de décrire d’une façon percutante la menace que subit le monde marin et les risques que de braves militants prennent pour essayer d’arrêter le carnage et d’empêcher la tuerie des espèces marines

Molecular and biochemical studies of some yeast strains

This work focuses on detecting the level of polymorphisms among eleven KSA and Egyptian yeast strains, as efficient tools to assess the genetic relationships and development of yeast strain-specific molecular fingerprints. Moreover, estimation of the amino acid concentration was efficient in selecting the protein rich strains for animal feeding source. To detect the polymorphism among the yeast strains at the molecular level, 8 random amplified polymorphic DNA (RAPD), 5 inter simple sequence repeat (ISSR), and 8 specific simple sequence repeat (SSR) pair of primers were used. The total number of fragments produced by RAPD primers was 46 fragments and represented 52% of polymorphism. Also, number of fragments produced by ISSR and SSR primers was 45 fragments and recorded 63 and 77% of polymorphism among the strains, respectively. The amino acid analysis showed that yeast strains, Rhodotorula glutinis (Y.1); Schwanniomyces occidentalis (Y.2); Debaryomyces hansenii (Y.8); Kluyveromyces lactis (Y.9) and Pichia jadinii (Y.10) contained almost double the amount of total amino acids compared to the rest of the eleven strains used. The different molecular markers have confirmed each other and supported the biochemical analysis data, because the clustering  analysis has shown that the previous five strains, (Y.1); (Y.2); (Y.8); (Y.9) and (Y.10), were falling together in the same sub cluster.Key words: Yeast, molecular markers, biochemical analysis

Kinetics and physico-chemical properties of alkali activated blast-furnace slag/basalt pastes

AbstractGranulated blast-furnace slag (GBFS) is a by-product of the metallurgical industry and consists mainly of lime and calcium–magnesium aluminosilicates that defined as the glassy granular material formed by rapid cooling of molten slag with excess water resulting in an amorphous structure. Alkali-activated slag (AAS) binders have taken a great interest from researchers due to its manufacturing process which has important benefits from the point of view of the lower energy requirements and lower emission of greenhouse gases with respect to the manufacturing of Portland cement. In this study, GBFS was replaced by 20, 40 and 60wt.% of basalt activated by 6wt.% of alkali mixture composed of 1:1 sodium hydroxide (SH) and liquid sodium silicate (LSS) mixed with sea water and cured in 100% relative humidity up to 90days. The physic-chemical parameters were studied by determination of setting time, combined water content, bulk density and compressive strength. As the amount of basalt increases the setting time as well as compressive strength decreases while the bulk density increases. The compressive strength values of dried pastes are greater than those of saturated pastes. The hydrated products are identified by TGA/DTG analysis, IR spectroscopy and scanning electron microscopy (SEM)