RECHERCHE SUR LA PERIODE D’ECHANTILLONNAGE DES FEUILLES D’ABRICOTIER, CULTIVE DANS LA REGION DE BISKRA (ALGERIE). RESEARCH ON THE SAMPLING PERIOD THE LEAVES APRICOT, CULTIVATED IN THE REGION OF BISKRA (ALGERIA)

Dans le cadre de la nouvelle politique agricole visant un meilleur développement de l'agriculture algérienne afin d'aboutir à lasécurité alimentaire. L'arboriculture fruitière notamment l’abricotier a connue une ampleur certaine, marquée par une extensiondes plantations fruitières dans différentes zones pédoclimatiques dont certaines diffèrent de celles des zones traditionnelles dela culture.L'espèce abricotier (Prunus armeniaca L.) marque un bon comportement dans ces situations et a donner des résultats trèsencourageants surtout en zones arides et semi arides. Ces derniers divergent de multiples facteurs entre autre la nutritionminérale.Cette contribution s'inscrit dans le cadre d'une évaluation de la nutrition minérale de trois variétés d'abricotier durant les années2005/06 et en 2006/07 pour une seule variété, cultivées dans une zone aride (commune de Doucen, w. Biskra Algérie). Cettecaractérisation nutritionnelle est fondée essentiellement sur l’analyse physicochimique du sol et des feuilles.D'une manière générale, les résultats d'analyses comparés aux normes établies indiquent des nutritions azotée, calcique etmagnésienne équilibrées et l'alimentation potassique s'avère satisfaisante. Ce qui exige forcement un contrôle périodique pourdécliner tout risque de carence en ces éléments. Pour le cas du phosphore, il marque des faibles proportions au niveau desfeuilles, traduites par une mauvaise alimentation des arbres

First ampelometric study of autochthonous grapevines in Algeria: Germplasm collection of Mascara

Ampelometric studies on 26 varieties of Vitis vinifera L. belonging to the germplasm existing in the collection of Tighennif (Mascara), the most important conservatory of local grapevine varieties existing in Algeria were carried out to characterize this gene pool, the phyllometric measurement method proposed by MARTÍNEZ and GRENAN was applied to establish a cultivar specific adult leaf. Statistical analysis was performed to identify the most discriminating parameters, namely, size of angles and depth of the lateral sinuses in comparison to the lengths of the veins, especially those on the left side of the leaf. Thus, cultivars with common features such as 'Bezoul el Khadem' and 'Ahmar de Mechtras III', 'Toutrissine' and 'Aberkane' and 'Amellal' and 'Torki' were clustered together. For seven varieties the average leaf has been reconstructed.

Molecular identification and genetic relationships of Algerian grapevine cultivars maintained at the germplasm collection of Skikda (Algeria)

We have used nuclear and chloroplast microsatellite markers to characterize a collection of 36 Algerian grapevine (Vitis vinifera L.) accessions maintained at the germplasm collection of Skikda (Algeria). The genetic diversity observed within the collection was comparable to what has been described for cultivated accessions of grapevine. Moreover, chlorotype C, associated to eastern accessions and highly frequent among table grape cultivars, was overrepresented in the collection. Genotype comparisons among the accessions and published cultivar genotypes identified a few synonyms within the collection as well as putative synonyms for Algerian accessions such as 'Aïn el Kelb', 'Ahmar Mechtras', 'Ahmar de Mascara' or 'Bouni' among cultivars grown in both Eastern and Western areas of the Mediterranean basin. Furthermore, the study of genetic relationships among the Algerian accessions suggests the existence of close relatedness within some groups of cultivars that could have been originated by spontaneous hybridization and seed propagation.

Infection néonatale bactérienne précoce : Quand mettre sous antibiotique et quelle antibiothérapie ? Early bacterial neonatal infection: When to indicate antibiotic treatment and what antibiotic therapy ?

Objective. Propose a relevant management strategy that can identify newborns with a bacterial infectious risk and those under clinical monitoring alone or in combination with parenteral antibiotic therapy.Methods. Retrospective study carried out between SA < 42, suspected of early bacterial infection and monitored in Maternity and in the Neonatology Unit of the Hospital Group Carnelle Portes of Oise [Val France]. The clinical-biological and bacteriological data, the therapeutic strategy and the evolution are analyzed. Results. Two hundred and forty newborns were eligible and divided into three groups: 120 asymptomatic newborns with antenatal criteria for bacterial infectious risk [G1NAS], 70 symptomatic newborns with antenatal criteria for bacterial infectious risk [G2NSCARIB] and 50 symptomatic newborns without antenatal criteria of bacterial infectious risk [G3NSSCARIB]. Inflammatory biology is limited tocolonized G1NAS newborns and symptomatic groups. The identified bacteria [Peripheral samples, gastric fluid, blood and cerebrospinal fluid] were mainly the Streptococcus of the group and the E Coli. Antibiotic therapy has been shown to be useful in asymptomatic newborns with inflammatory syndrome and bacteria identified on peripheral samples and gastric fluid, but  also in all symptomatic newborns. Conclusion. In a early bacterial infection, an interventionist attitude is required, but early antibiotic therapy is only useful in the situation of symptomatic newborns. On the otherhand, in the asymptomatic newborns, antibiotic therapy will be reserved for those carrying both an identified bacteria and an inflammatory syndrome. Contexte et objectif. L‟infection néonatale bactérienne précoce est greffée d‟une forte mortalité et morbidité conduisant à une antibiothérapie probabiliste sans délai souvent à posteriori inutile. L‟objectif du présent travail était de proposer une stratégie de prise en charge pertinente susceptible de bien identifier les nouveau-nés à risque infectieux bactérien et ceux relevant d‟une surveillance clinique seule ou associée à une antibiothérapie parentérale.    Méthodes. Etude documentaire menée entre janvier 2014 et janvier 2016 sur des nouveau-nés de 36≥SA<42, suspects d‟infection bactérienne précoce et suivis en Maternité et dans l‟unité de Néonatologie du Groupe Hospitalier Carnelle Portes de l‟Oise [Val D‟Oise, France]. Les données clinico-biologiques et bactériologiques, la stratégie thérapeutique et l‟évolution sont analysées.  Résultats. Deux cent quarante nouveau-nés [NNES] ont été éligibles et repartis en trois groupes : 120 NNES asymptomatiques avec critères anténatals de risque infectieux bactérien [G1NAS], 70 NNES symptomatiques avec critères anténatals de risque infectieux bactérien [G2NSCARIB] et 50 NNES symptomatiques sans critères anténatals de risque infectieux bactérien [G3NSSCARIB]. La biologie inflammatoire est limitée aux NNES du groupe G1NAS colonisés et aux groupes symptomatiques. Les germes identifiés [Prélèvements périphériques, liquide gastrique, sang et liquide céphalorachidien] ont été principalement le Streptocoque du groupe β et l‟E Coli. L‟antibiothérapie s‟est avérée utile chez les NNES asymptomatiques avec syndrome inflam-matoire et germes identifiés sur les prélèvements périphériques et liquide gastrique, mais aussi chez tous les NNES symptomatiques.                                                                    Conclusion. Chez un NNE âgé de ≥ 36SA et suspect d‟infection bactérienne précoce, une attitude interventionniste est de rigueur, mais l‟antibiothérapie sans délai n‟est utile que dans les situations des NNES symptomatiques. En revanche, chez les NNES asymptomatiques, l‟antibiothérapie sera réservée à ceux porteurs à la fois d‟un germe et d‟un syndrome inflammatoire

A comparison between ultraviolet disinfection and copper alginate beads within a vortex bioreactor for the deactivation of bacteria in simulated waste streams with high levels of colour, humic acid and suspended solids.

We show in this study that the combination of a swirl flow reactor and an antimicrobial agent (in this case copper alginate beads) is a promising technique for the remediation of contaminated water in waste streams recalcitrant to UV-C treatment. This is demonstrated by comparing the viability of both common and UV-C resistant organisms in operating conditions where UV-C proves ineffective - notably high levels of solids and compounds which deflect UV-C. The swirl flow reactor is easy to construct from commonly available plumbing parts and may prove a versatile and powerful tool in waste water treatment in developing countries

Mre11-Rad50 Promotes Rapid Repair of DNA Damage in the Polyploid Archaeon Haloferax volcanii by Restraining Homologous Recombination

Polyploidy is frequent in nature and is a hallmark of cancer cells, but little is known about the strategy of DNA repair in polyploid organisms. We have studied DNA repair in the polyploid archaeon Haloferax volcanii, which contains up to 20 genome copies. We have focused on the role of Mre11 and Rad50 proteins, which are found in all domains of life and which form a complex that binds to and coordinates the repair of DNA double-strand breaks (DSBs). Surprisingly, mre11 rad50 mutants are more resistant to DNA damage than the wild-type. However, wild-type cells recover faster from DNA damage, and pulsed-field gel electrophoresis shows that DNA double-strand breaks are repaired more slowly in mre11 rad50 mutants. Using a plasmid repair assay, we show that wild-type and mre11 rad50 cells use different strategies of DSB repair. In the wild-type, Mre11-Rad50 appears to prevent the repair of DSBs by homologous recombination (HR), allowing microhomology-mediated end-joining to act as the primary repair pathway. However, genetic analysis of recombination-defective radA mutants suggests that DNA repair in wild-type cells ultimately requires HR, therefore Mre11-Rad50 merely delays this mode of repair. In polyploid organisms, DSB repair by HR is potentially hazardous, since each DNA end will have multiple partners. We show that in the polyploid archaeon H. volcanii the repair of DSBs by HR is restrained by Mre11-Rad50. The unrestrained use of HR in mre11 rad50 mutants enhances cell survival but leads to slow recovery from DNA damage, presumably due to difficulties in the resolution of DNA repair intermediates. Our results suggest that recombination might be similarly repressed in other polyploid organisms and at repetitive sequences in haploid and diploid species

A Major Role of the RecFOR Pathway in DNA Double-Strand-Break Repair through ESDSA in Deinococcus radiodurans

In Deinococcus radiodurans, the extreme resistance to DNA–shattering treatments such as ionizing radiation or desiccation is correlated with its ability to reconstruct a functional genome from hundreds of chromosomal fragments. The rapid reconstitution of an intact genome is thought to occur through an extended synthesis-dependent strand annealing process (ESDSA) followed by DNA recombination. Here, we investigated the role of key components of the RecF pathway in ESDSA in this organism naturally devoid of RecB and RecC proteins. We demonstrate that inactivation of RecJ exonuclease results in cell lethality, indicating that this protein plays a key role in genome maintenance. Cells devoid of RecF, RecO, or RecR proteins also display greatly impaired growth and an important lethal sectoring as bacteria devoid of RecA protein. Other aspects of the phenotype of recFOR knock-out mutants paralleled that of a ΔrecA mutant: ΔrecFOR mutants are extremely radiosensitive and show a slow assembly of radiation-induced chromosomal fragments, not accompanied by DNA synthesis, and reduced DNA degradation. Cells devoid of RecQ, the major helicase implicated in repair through the RecF pathway in E. coli, are resistant to γ-irradiation and have a wild-type DNA repair capacity as also shown for cells devoid of the RecD helicase; in contrast, ΔuvrD mutants show a markedly decreased radioresistance, an increased latent period in the kinetics of DNA double-strand-break repair, and a slow rate of fragment assembly correlated with a slow rate of DNA synthesis. Combining RecQ or RecD deficiency with UvrD deficiency did not significantly accentuate the phenotype of ΔuvrD mutants. In conclusion, RecFOR proteins are essential for DNA double-strand-break repair through ESDSA whereas RecJ protein is essential for cell viability and UvrD helicase might be involved in the processing of double stranded DNA ends and/or in the DNA synthesis step of ESDSA

Molecular identification and genetic relationships of Algerian grapevine cultivars maintained at the germplasm collection of Skikda (Algeria)

We have used nuclear and chloroplast microsatellite markers to characterize a collection of 36 Algerian grapevine (Vitis vinifera L.) accessions maintained at the germplasm collection of Skikda (Algeria). The genetic diversity observed within the collection was comparable to what has been described for cultivated accessions of grapevine. Moreover, chlorotype C, associated to eastern accessions and highly frequent among table grape cultivars, was overrepresented in the collection. Genotype comparisons among the accessions and published cultivar genotypes identified a few synonyms within the collection as well as putative synonyms for Algerian accessions such as 'Aïn el Kelb', 'Ahmar Mechtras', 'Ahmar de Mascara' or 'Bouni' among cultivars grown in both Eastern and Western areas of the Mediterranean basin. Furthermore, the study of genetic relationships among the Algerian accessions suggests the existence of close relatedness within some groups of cultivars that could have been originated by spontaneous hybridization and seed propagationThis work was supported by research project GEN2003-20232-C2 from the Spanish Ministry for Science and Education (MEC) to JMZ and by a predoctoral fellowship from Algerian Ministry of Higher Education and Scientific Research to ZL.Peer reviewe

Molecular identification and genetic relationships of Algerian grapevine cultivars maintained at the germplasm collection of Skikda (Algeria)

We have used nuclear and chloroplast microsatellite markers to characterize a collection of 36 Algerian grapevine (Vitis vinifera L.) accessions maintained at the germplasm collection of Skikda (Algeria). The genetic diversity observed within the collection was comparable to what has been described for cultivated accessions of grapevine. Moreover, chlorotype C, associated to eastern accessions and highly frequent among table grape cultivars, was overrepresented in the collection. Genotype comparisons among the accessions and published cultivar genotypes identified a few synonyms within the collection as well as putative synonyms for Algerian accessions such as 'Aïn el Kelb', 'Ahmar Mechtras', 'Ahmar de Mascara' or 'Bouni' among cultivars grown in both Eastern and Western areas of the Mediterranean basin. Furthermore, the study of genetic relationships among the Algerian accessions suggests the existence of close relatedness within some groups of cultivars that could have been originated by spontaneous hybridization and seed propagationThis work was supported by research project GEN2003-20232-C2 from the Spanish Ministry for Science and Education (MEC) to JMZ and by a predoctoral fellowship from Algerian Ministry of Higher Education and Scientific Research to ZL.Peer reviewe