Severe Tricuspid Valve Endocarditis Related to Tunneled Catheters in Chronic Hemodialysis Patients: When Should the Catheter be Removed?

Introduction: Hemodialysis (HD) patients are predisposed to infective endocarditis (IE) mainly due to repeated manipulation of the vascular access. However, catheter seeding and IE may also result from a distant infection site.Case series: A diabetic patient who was maintained on regular HD through a permanent catheter in the right internal jugular vein presented with septicemia of urinary origin due to Pseudomonas aeruginosa. He was treated with injectable antibiotics for 15 days. Few days after the end of the treatment period he presented with inflammation of the catheter exit site. Blood cultures revealed Pseudomonas aeruginosa and echocardiography showed a large vegetation on the tricuspid valve, confirming the diagnosis of IE. The patient improved after catheter removal and treatment with ceftazidime, vancomycin and amikacin. Another patient who was maintained on chronic HD through a tunneled catheter in the right internal jugular vein presented with a limited infection in the sub-cutaneous tunnel of the catheter that improved after treatment with injectable antibiotics. Two months later, he presented with severe sepsis without signs of local infection of the catheter. Chest radiography showed right sided infiltrates. Injectable antibiotic therapy was given without improvement. Blood cultures were negative but echocardiography showed a large tricuspid valve vegetation. Antibiotic regimen was modified to include vancomycin, amikacin and ceftazidime and the catheter was removed. Unfortunately, the patient died two days after diagnosing IE.Conclusion: catheter seeding and IE may be a consequence of sepsis originating away from the HD catheter site. Tunneled catheters may need to be pre-emptively removed in such situations to prevent serious IE.Keywords: Hemodialysis; Infective Endocarditis; Tricuspid Valv

Analysis of diversity genetic of Moroccan net blotch populations using amplified fragment length polymorphism (AFLP) markers

Net blotch caused by Pyrenophora teres f. teres is the most harmful foliar disease in barley generating significant economic losses in Morocco. Populations of P. teres f. teres were collected from different regions of Morocco. Thirty five (35) P. teres f. teres isolates, single conidial, were isolated and were subjected to molecular study using amplified fragment length polymorphism (AFLP) technique. Out of the fourteen primers combinations tested, four primers combinations were selected to disclose the polymorphism between the different P. teres f. teres isolates. The molecular characterization of these isolates showed high degree of polymorphism reaching 95% and identifying 25 specific genotypes. The genetic variability of the different isolates of P. teres f. teres within and between Moroccan regions was highlighted, disclosing no linkage between the isolates and their geographical origins. This result might be due to informal material flow between regions.Key words: Barley, net blotch, Pyrenophora teres f. teres, amplified fragment length polymorphism (AFLP), genetic diversity

Structural disorder and its effects in laser wavelength GaAs–AlxGa1−xAs superlattice

Nous revisitons ici la théorie, utilisée en analyse des profils de raies de diffraction des rayons X et des neutrons, relative à la fonction de forme du pic dite de pseudo -Voigt (notée pV). Nous présentons une généralisation des expressions de la largeur intégrale et à mi-hauteur de la fonction pV, de la transformée de Fourier de cette fonction ainsi que du seuil du parametre de mélange η. Nous incorporons nos résultats dans la procédure de fit, ce qui améliore les facteurs de précision.Proučavamo optički aktivan sustav GaAs–AlxGa1−xAs načinjen na GaAs podlozi s ciljem postizanja laserske emisije u širokom infracrvenom području (9 to 90 µm). Ispitujemo učinak koncentracije aluminija “x” i širine potencijalne jame “a” kako bi se odredio njihov utjecaj na lasersku valnu duljinu. Mjerenjima prolaska svjetlosti pokazujemo da se uvođenjem strukturne nepravilnosti (uz zadržavanja periodičnosti) dvo- i troslojeva u našim superrešetkama postiže vjerojatnost prolaska jednaka 1, što znači da su odnosna stanja rezonantna.This study focuses on optically active system GaAs–AlxGa1−xAs based on the GaAs substrate, with the aim to achieve lasers emitting in a wide range of infrared (9 to 90 µm). The effect of aluminium concentration “x” and the potential well width “a” is studied to see their direct effects on the laser wavelength. We show from measurements of transmission that the introduction of a structural disorder (preserving the system periodicity) by doublet or triplet within our superlattices provides delocalised electronic states characterized by a probability of transmission equal to 1, meaning that the corresponding state is resonant

Virulence of Moroccan f. Revealed by International Differential Barley Genotypes

Pyrenophora teres f. teres (Ptt), causing net blotch in barley, is an important and frequently isolated leaf pathogen across the globe. The virulence spectrum of Ptt from North Africa including Morocco is poorly understood. Sixteen barley genotypes were challenged, at seedling stage, with 15 Ptt isolates that were collected from different agroecological zones of Morocco. The experiment was conducted in a factorial arrangement of treatments in a randomized complete block design with three replicates. The ANOVA revealed highly significant (P < 0.001) effects of genotype (G), isolate (I) and G×I interaction explaining 23.2, 62.5, and 13.9% of the variation, respectively. Therefore, the current study revealed highly diverse virulence pattern of Moroccan isolates. Furthermore, the results indicated that minor virulence of Ptt isolates dominated over virulence interaction. In addition, Taffa (6-rowed) and Aglou (2 rowed), had the highest level of resistance to Ptt, while Coast and Rabat071 were the most susceptible genotypes. Pt2, Pt7, Pt8 and Pt4 were being the most virulent isolates, while Pt10 and Pt11 were the least virulent isolates. The emergence of the new Ptt pathotypes, which were highly virulent to durable resistance in Rabat071 posed a risk of breaking down the currently deployed resistance to net blotch in Morocco. A careful evaluation and selection of Ptt isolates based on minor virulence pattern to barley genotypes is essential for successful barley breeding program for resistance to net blotch in Morocco

Structural disorder and its effects in laser wavelength GaAs–AlxGa1−xAs superlattice

Nous revisitons ici la théorie, utilisée en analyse des profils de raies de diffraction des rayons X et des neutrons, relative à la fonction de forme du pic dite de pseudo -Voigt (notée pV). Nous présentons une généralisation des expressions de la largeur intégrale et à mi-hauteur de la fonction pV, de la transformée de Fourier de cette fonction ainsi que du seuil du parametre de mélange η. Nous incorporons nos résultats dans la procédure de fit, ce qui améliore les facteurs de précision.Proučavamo optički aktivan sustav GaAs–AlxGa1−xAs načinjen na GaAs podlozi s ciljem postizanja laserske emisije u širokom infracrvenom području (9 to 90 µm). Ispitujemo učinak koncentracije aluminija “x” i širine potencijalne jame “a” kako bi se odredio njihov utjecaj na lasersku valnu duljinu. Mjerenjima prolaska svjetlosti pokazujemo da se uvođenjem strukturne nepravilnosti (uz zadržavanja periodičnosti) dvo- i troslojeva u našim superrešetkama postiže vjerojatnost prolaska jednaka 1, što znači da su odnosna stanja rezonantna.This study focuses on optically active system GaAs–AlxGa1−xAs based on the GaAs substrate, with the aim to achieve lasers emitting in a wide range of infrared (9 to 90 µm). The effect of aluminium concentration “x” and the potential well width “a” is studied to see their direct effects on the laser wavelength. We show from measurements of transmission that the introduction of a structural disorder (preserving the system periodicity) by doublet or triplet within our superlattices provides delocalised electronic states characterized by a probability of transmission equal to 1, meaning that the corresponding state is resonant