A Survey on some date palm orchards parameters applicable in date palm mechanization

The aim of this work is determination a several date palm related-information to be utilized in designing of date palm service machines. Different parameters were collected from 37 farms in Biskra province, due its importance in Algerian dates production, such as: height of trees (to crown), circumferences of trees and position of the dates bunch in the tree, number of tractor, irrigation mode. According to the results of this survey, several points were defined applicable in date palm mechanization, such as the machine work height must reach up 8 m higher, in minimum and the irrigation channels and the intercropping are, generally, along the rows which facility the displacement of wheeled machine

Dynamique spatio-temporelle des ravageurs insectes et leurs parasites dans l’oasis de Biskra

L’agriculture dans la région sud de l’atlas saharien et spécialement dans la région de Sidi Khales est basée sur la culture du palmier dattier. Cette espèce est menacée par des insectes ravageurs, la pyrale des dattes (Ectomyelois ceratoniae), la cochenille blanche du palmier dattier (Parlatoria blanchardi) , la pyrale de Kûhn Ephestia kuehniella et coléoptère de fruits Carpophilus hemipterus. L’évolution des populations des ravageurs insectes et leurs parasitoides fait l’objet d’une étude menée dans la stations SAAIDI , Oasis de Sidi Khaled , en 2016- 2017et 2018 . Cette étude montre que le taux d’infestation des dattes par la pyrale est important dans une palmeraie traditionnelle. La palmeraie moderne semble moins attaquée. L’effectif des adultes ailés durant la période d’échantillonnage 2016-2017 est élevé en automne avec un nombre de 50±0,6 individus enregistrés le début du mois de novembre Alors que, le nombre le plus faible est marqué durant le mois de février. L’effectif global des adultes devient important aussi durant la fin de la période printanière avec un effectif de 25±0,2 individus enregistrés le début du mois de mai 2017. L’apparition de la population de la pyrale des dattes semble être précoce au niveau de la palmeraie traditionnelle. Cela peut être expliqué par la densité du couvert végétale et la présence de plusieurs plantes hôtes. la variété Deglet Nour est la plus infestée par la pyrale des dattes avec un taux d’infestation de 193±0,6. Alors que la variété Deglat baida présente le taux d’infestation le plus faible, 39,66 ±0,1. Alors qu’au niveau de la palmeraie moderne, la variété la plus infestée est Mechdeglat avec un taux d’infestation de 144,66±0,4. Pour la variété Deglat baida , le taux d’infestation est faible , 58,33±0,1. L’effectif des adultes ailés de la pyrale de Kûhn est important durant la période hivernale. Le premier pic d’évolution de la population est enregistré le début du mois de décembre. L’effectif de la population de cette espèce semble identique dans les deux palmeraies. La relation entre la température minimale nocturne et l’effectif de la population des larves de la cochenille blanche est positive, R2= 0,42. Il existe une relation entre cette dernière et le développement de ce ravageur. Carpophilus hemipterus est présente en automne et en printemps. Il faut signalé qu’il existe deux période de ropos , deux mois en hiver et presque un mois en été. la fertilité de Bracon hebetor est importante . Cette dernière varie entre 75,11 et 98 % avec une moyenne de 92,44 ± 2.33% (n=20). Elle est variable d’une femelle à une autre

Phenolic contents and in vitro antioxidant activity of four commonly consumed nuts in Algeria

This study was carried out to determine the phenolic contents and the antioxidant activity of four nuts with different solvent extract. Total phenolic compounds, flavonoids, and proanthocyanidin were quantified. Antioxidant activity was evaluated by various in vitro tests, including ferric reducing power, phosphomolybdenum method assay, and free radical scavenging activity. The results showed that the total phenolic contents varied between 0.30 g GAE/100 g (peanuts) and 1.65 g GAE/100 g (walnuts); the flavonoid contents varied between 0.17 g QE/100 g (peanuts) and 0.41 g QE/100 g (hazelnut). The phenolic contents of four nut extracts exhibit potent antioxidant activity. Indeed, walnuts were the richest in total phenolic content and demonstrated the highest potential for overall antioxidant capacity using ferric reducing power assay (FRP), phosphomolybdenum method assay, and free radical scavenging activity (FRSA). Phenolic amounts positively correlated with antioxidant activity tested

A hybrid next generation transcript sequencing-based approach to identify allelic and homeolog-specific single nucleotide polymorphisms in allotetraploid white clover

peer-reviewedBackground: White clover (Trifolium repens L.) is an allotetraploid species possessing two highly collinear ancestral sub-genomes. The apparent existence of highly similar homeolog copies for the majority of genes in white clover is problematic for the development of genome-based resources in the species. This is especially true for the development of genetic markers based on single nucleotide polymorphisms (SNPs), since it is difficult to distinguish between homeolog-specific and allelic variants. Robust methods for categorising single nucleotide variants as allelic or homeolog-specific in large transcript datasets are required. We illustrate one potential approach in this study. Results: We used 454-pyrosequencing sequencing to generate ~760,000 transcript sequences from an 8th generation white clover inbred line. These were assembled and partially annotated to yield a reference transcript set comprising 71,545 sequences. We subsequently performed Illumina sequencing on three further white clover samples, generating 14 million transcript reads from a mixed sample comprising 24 divergent white clover genotypes, and 50 million reads on two further eighth generation white clover inbred lines. Mapping these reads to the reference transcript set allowed us to develop a significant SNP resource for white clover, and to partition the SNPs from the inbred lines into categories reflecting allelic or homeolog-specific variation. The potential for using haplotype reconstruction and progenitor genome comparison to assign haplotypes to specific ancestral sub-genomes of white clover is demonstrated for sequences corresponding to genes encoding dehydration responsive element binding protein and acyl-coA oxidase. Conclusions: In total, 208,854 independent SNPs in 31,715 reference sequences were discovered, approximately three quarters of which were categorised as representing allelic or homeolog-specific variation using two inbred lines. This represents a significant resource for white clover genomics and genetics studies. We discuss the potential to extend the analysis to identify a “core set” of ancestrally derived homeolog specific variants in white clover.Department of Agriculture Food & the Marine, Ireland - Research Stimulus Fund (RSF 07–566

Determination of nanoparticle size distribution together with density or molecular weight by 2D analytical ultracentrifugation

Nanoparticles are finding many research and industrial applications, yet their characterization remains a challenge. Their cores are often polydisperse and coated by a stabilizing shell that varies in size and composition. No single technique can characterize both the size distribution and the nature of the shell. Advances in analytical ultracentrifugation allow for the extraction of the sedimentation (s) and diffusion coefficients (D). Here we report an approach to transform the s and D distributions of nanoparticles in solution into precise molecular weight (M), density (ρP) and particle diameter (dp) distributions. M for mixtures of discrete nanocrystals is found within 4% of the known quantities. The accuracy and the density information we achieve on nanoparticles are unparalleled. A single experimental run is sufficient for full nanoparticle characterization, without the need for standards or other auxiliary measurements. We believe that our method is of general applicability and we discuss its limitations

Impact of soil treatment on internal erosion resistance and hydro-mechanical characteristics of a silty soil

The aim of this paper is to examine the impact of soil treatment on the internal erosion and the hydro-mechanical characteristics of a silty soil. The study is focused on the treatment by kaolinite, bentonite, lime and cement, with different amounts and curing periods. A new enhanced Hole Erosion Test was developed especially to study the internal erosion of treated soils using high hydraulic shear stresses. The use of clayey products decreases both the hydraulic conductivity and the coefficient of soil erosion without changing the mechanical behavior. Lime and cement treatment induce a significant improvement of both internal erosion resistance and strength, and also keep the same level of hydraulic conductivity, and may even decrease it in some cases. The magnitude of these modifications is related to the nature and amount of the treatment product, and the curing period. The cross relationships between the hydraulic conductivity, the unconfined compression strength and the internal erosion were also assessed

LKB1 interacts with and phosphorylates PTEN: a functional link between two proteins involved in cancer predisposing syndromes

Germline mutations of the LKB1 (STK11) tumor suppressor gene lead to Peutz-Jeghers syndrome (PJS) and predisposition to cancer. LKB1 encodes a serine/threonine kinase generally inactivated in PJS patients. We identified the dual phosphatase and tumor suppressor protein PTEN as an LKB1-interacting protein. Several LKB1 point mutations associated with PJS disrupt the interaction with PTEN suggesting that the loss of this interaction might contribute to PJS. Although PTEN and LKB1 are predominantly cytoplasmic and nuclear, respectively, their interaction leads to a cytoplasmic relocalization of LKB1. In addition, we show that PTEN is a substrate of the kinase LKB1 in vitro. As PTEN is a dual phosphatase mutated in autosomal inherited disorders with phenotypes similar to those of PJS (Bannayan-Riley-Ruvalcaba syndrome and Cowden disease), our study suggests a functional link between the proteins involved in different hamartomatous polyposis syndromes and emphasizes the central role played by LKB1 as a tumor suppressor in the small intestin

Molecular and Clinical Characteristics in 46 Families Affected with Peutz-Jeghers Syndrome

Germline mutations of the tumor suppressor gene LKB1/STK11 are responsible for the Peutz-Jeghers syndrome (PJS), an autosomal-dominant disorder characterized by mucocutaneous pigmentation, hamartomatous polyps, and an increased risk of associated malignancies. In this study, we assessed the presence of pathogenic mutations in the LKB1/STK11 gene in 46 unrelated PJS families, and also carried genotype-phenotype correlation in regard of the development of cancer in 170 PJS patients belonging to these families. All LKB1/STK11 variants detected with single-strand conformational polymorphism were confirmed by direct sequencing, and those without LKB1/STK11 mutation were further submitted to Southern blot analysis for detection of deletions/rearrangements. Statistical analysis for genotype-phenotype correlation was performed. In 59% (27/46) of unrelated PJS cases, pathogenic mutations in the LKB1/STK11 gene, including 9 novel mutations, were identified. The new mutations were 2 splice site deletion-insertions, 2 missenses, 1 nonsense, and 4 abnormal splice sites. Genotype-phenotype analysis did not yield any significant differences between patients carrying mutations in LKB1/STK11 versus those without mutations, even with respect to primary biliary adenocarcinoma. This study presents the molecular characterization and cancer occurrence of a large cohort of PJS patients, increases the mutational spectrum of LKB1/STK11 allelic variants worldwide, and provides a new insight useful for clinical diagnosis and genetic counseling of PJS familie

Réalisation d'un pollinisateur du palmier dattier

Plusieurs chercheurs ont tenté de mécaniser la pollinisation de palmier dattier au vu de son importance. En effet, le présent travail contribue à l’enrichissement de ce sujet mettant à la disposition des phœniciculteurs un nouveau dispositif de pollinisation. Le pollinisateur réalisé est constitué d’une poudreuse monté à la tête d’une perche télescopique. Nous avons mené des tests sur ce pollinisateur à Touggourt et à Biskra (Algérie). Le rendement obtenu par le pollinisateur a été le même que celui obtenu par la méthode traditionnelle. L’appareil a coûté une somme qui est moins que le coût de pollinisation de plus de 25 palmiers par la méthode traditionnelle. De plus la pollinisation par l’appareil a duré la moitié du temps que celle exigée par la méthode traditionnelle. La sécurité de l’agriculteur est bien assurée puisque il ne grimpe plus les palmiers, ce qui est aussi très important. Ce travail propose une alternative efficace, vu les résultats prometteurs obtenus avec le pollinisateur sur les plans économique, sécuritaire et gain de temps. Et lorsque la fonction de ce pollinisateur se base sur la dispersion de pollen, nous avons déterminé que le meilleur pourcentage pollen/farine de blé est de 20 %. Mots clés: Palmier dattier, pollinisation, mécanisation, main d’oeuvre, pollinisateur  Several studies have attempted to mechanize the date palm pollination given its importance. Indeed, this work contributes to the enrichment of this topic by providing a new pollination device to date palm growers. This pollinator consists of a powdering device mounted on a telescopic pole. Field tests of this pollinator were conducted in Touggourt and Biskra (Algeria). The date yield obtained with this pollinator was the same as that of the traditional pollination method. The cost of the device was less than the cost of pollinating about 25 palm trees by the traditional method. Moreover, pollination by this device required half the time which was necessary by the traditional method of pollination. With this device, the safety of the farmer is assured since he doesn’t have to climb the palm tree anymore which is also very important. The promising research results obtained testing the developed pollination device makes this pollinator an alternative option for farmers in economic, security and time savings terms. And when the function of this pollinator is based on the dispersion of pollen, we determined that the best percentage pollen / wheat flour was 20 %. Keywords: Date palm, pollination, mechanization, labour, pollinato