The geology and geochronology of Al Wahbah maar crater, Harrat Kishb, Saudi Arabia

Al Wahbah is a large (∼2.2 km diameter, ∼250 m deep) maar crater in the Harrat Kishb volcanic field in western Saudi Arabia. It cuts Proterozoic basement rocks and two Quaternary basanite lava flows, and is rimmed with an eroded tuff ring of debris from the phreatomagmatic explosion that generated the crater. A scoria cone on the northern wall of the crater was dissected by the explosion and exposes a dolerite plug that was intruded immediately prior to crater formation. The dolerite plug yields a <sup>40</sup>Ar/<sup>39</sup>Ar age of 1.147 ± 0.004 Ma. This is the best possible estimate of the time Al Wahbah crater formed. It is a few tens of thousand years younger than the age of the lower and upper basalt flows, 1.261 ± 0.021 Ma and 1.178 ± 0.007 Ma respectively. A dolerite dyke exposed within the basement in the wall of the crater is dated at 1.886 ± 0.008 Ma. This is the most precise age so far determined for the initiation of basaltic volcanism of Harrat Kishb, and confirms that it is significantly younger than the other post-rift volcanic provinces in the region. This study provides constrains the timing of humid climatic conditions in the region and suggests that the Quaternary basaltic volcanism that stretches the length of the western side of the Arabian peninsula may prove to be useful for establishing palaeoclimatic conditions

Label-free, in-solution screening of peptide libraries for binding to protein targets using hydrogen exchange-mass spectrometry (HX-MS)

There is considerable interest in the discovery of peptide ligands that bind to protein targets. Discovery of such ligands is usually approached by screening large peptide libraries. However, the individual peptides must be tethered to a tag that preserves their individual identities (e.g. phage display or one-bead one-compound). To overcome this limitation, we have developed a method for screening libraries of label-free peptides for binding to a protein target in solution as a single batch. The screening is based on decreased amide hydrogen exchange by peptides that bind to the target. Hydrogen exchange was measured by mass spectrometry. We demonstrate the approach using a peptide library derived from the E. coli proteome that contained 6664 identifiable features. The library was spiked separately with a peptide spanning the calmodulin binding domain of endothelial nitric oxide synthase (eNOS, 494-513) and a peptide spanning the N-terminal twenty residues of bovine ribonuclease A (S peptide). Human calmodulin and bovine ribonuclease S (RNase S) were screened against the library. Using a novel data analysis workflow we identified the eNOS peptide as the only calmodulin binding peptide and S peptide as the only ribonuclease S binding peptide in the library

Microstructure characterization of sustainable light weight concrete using trapped air additions.

Light-weight aggregate and trapped air additions (TAD) affect concrete performance and lead to the production of light-weight concrete (LWC). In this research, fourteen mixes were designed to study the effects of TAD type and content and pozzolanic material (PZ) type on the microstructure characterization of concrete. Aluminum powder (AP) and lightcrete (LC) were used as TAD with content equal to (0%, 0.25%, 0.50%, 0.57%). The PZ included silica fume (SF) and fly ash (FA) with a content equal to 10% of the weight of cement. Tests were performed for compressive strength, density, SEM, EDS, XRD, and TGA/DTG. The results show that compressive strength and density are reduced as TAD ratios are increased

Synthesis and anti-mycobacterial evaluation of some new isonicotinylhydrazide analogues

AbstractThe synthesis of some new 3,4-disubstituted thiazolylideneisonicotinohydrazide derivatives 3a–k, 2-substituted thiazolidinylisonicotinamide derivatives 4a–d and pyrrolylisonicotinamide derivatives 5, 6 and 7 is described. The resulted compounds are evaluated for their in vitro antitubercular activity. The minimum inhibitory concentration (MIC) of compound 3g showed comparable in vitro activity to isoniazid against Mycobacterium tuberculosis H37Ra 7131 strain in concentration 9.77μg/mL

La transmission du savoir-faire agricole dans les fermes-écoles créées par la France en Afrique du Nord et en Syrie au début du xxe siècle

Représentant le premier degré de l’enseignement agricole de la Métropole en 1848, les fermes-écoles furent créées en Afrique du Nord et en Syrie entre 1922 et 1930. Ces établissements devaient former des aides ruraux qualifiés et moderniser l’agriculture. Dans cette nouvelle ère agronomique, motoculture, fertilisation, sélection végétale et activité expérimentale constituaient des moyens d’amélioration agricole. En dépit de leur nombre limité – deux en Algérie et en Tunisie, une au Maroc et en Syrie – ces fermes-écoles offraient à l’agriculture locale l’exemple de pratiques raisonnées. Cependant, elles ne présentaient pas aux élèves un modèle de gestion de l’entreprise agricole comme en Métropole. Les établissements d’Afrique du Nord avaient une administration étatique complexe. Toutefois, ces exploitations dispensaient aux jeunes ruraux une formation qui faisait défaut à ces pays essentiellement agricoles

Evaluation of Testicular Blood Flow and Ultrasonographic Measurements in Rams with Emphasis on Laterality

The current study aimed to measure the testicular ultrasonographic dimensions (length, width, thickness and volume) as well as spectral Doppler indices (resistive index and pulsatility index) of testicular artery, and to investigate the possible differences between the paired testes based on testicular dimensions and blood flow Doppler indices. Five Awassi rams of normal fertility, with a body weight 50-65 kg and aged 3-5 years were subjected to testicular ultrasound examination for testicular dimensions and pulsed-wave Doppler, twice monthly for five consecutive months. The testicular volume of the left testis (69.34±6.66 mm3) was higher than the right testis (66.85±5.46 mm3). Testicular thickness was significantly affected by the laterality of the testes (P<0.05). Doppler measures for RI (resistive index) as well as pulsatility index (PI) were slightly higher (P>0.05) in the right testicular artery rather than the left one. In conclusion, the testicular ultrasound measures and Doppler flow indices varied between the paired right and left testes in mature rams. In addition, the blood flow indices are highly correlated in the testicular artery of rams

Comparison between Utilization of Industrial Waste Steel Slag as Aggregate and Natural Aggregate in Underwater Self-compacting Concrete

An environmentally friendly approach to the disposal of waste materials, a difficult issue to cope with in today’s world, would only be possible through a useful recycling process. Steel slag is a byproduct of metal smelting and hundreds of tons of it are produced every year all over the world in the process of refining metals and making alloys. Coarse aggregate is one of these factors that have a significant influence on underwater self-compacting concrete (UWSCC). The work involves three groups with the total number of twenty seven underwater-concrete mixes. First group uses gravel, the second group uses steel slag, and the third group uses crushed dolomite. The test program was designed and arranged to consider the effect of four different parameters as follows; water binder ratio (w/p), high range water-reducing (HRWR) dosage, fine to coarse aggregate ratio and maximum size aggregate. The concrete mixtures were tested for slump, slump flow, slump flow time (T-500), V-funnel, L-box, GTM screen stability, washout loss method that is the plunge test CRDC61 which is widely used in North America, and compressive strength. The results show that UWSCC with industrial waste steel slag as aggregate has higher values of compressive strength and unit weight compared to UWSCC with natural aggregate

La scolarisation de l’apprentissage agricole en France : les fermes-écoles au service de l’agriculture et de son enseignement (19e siècle-début 20esiècle)

En dépit des rôles multiples qu’elles jouaient pour hâter et diffuser le progrès agricole, les fermes-écoles dans leur ensemble n’avaient pas fait l’objet d’une étude approfondie . Nous les étudions comme une voie spécifique de vulgarisation agricole tout au long du 19e et au 20e siècle, jusqu’en 1928 en métropole. La recherche menée traite également de leur mise en place par la France en Afrique du Nord et en Syrie durant la période de l’occupation jusqu’en 1942. Créées par des initiatives p..

Evaluation of insulin-like growth factor-I gene polymorphism in Egyptian small ruminant breeds

The genetic improvement of production traits can be developed through marker assisted selection. Insulin-like growth factor I (IGF-I) is a member of the somatotrophic axis which has a remarkable variation of its biological effect including protein synthesis and skeletal growth. This study aimed to detect the genetic polymorphism of IGF-1 in different Egyptian sheep and goat breeds. The amplified fragments at 320-bp were digested with HaeIII endonuclease and the results show the presence of three different genotypes: CC (15.71%), CG (29.29%) and GG (55.0%). The nucleotide sequence analysis of C and G alleles declared the presence of a single nucleotide polymorphism (C→G) at position 282. The nucleotide sequences of alleles C and G in sheep and goat were submitted to GenBank with the accession number: KX432965, KX432966, KX432967 and KX432968, respectively. In conclusion, a nucleotide substitution (C→G) was detected in IGF-I gene in Egyptian sheep and goat breeds resulting in the presence of three different genotypes; CC, CG and GG. The association of IGF-I polymorphism with different growth trait parameters were reported at significant levels, so, the genetic and SNP variations in IGF-I gene may be a potential molecular marker for growth traits in different Egyptian sheep and goat breeds.Keywords: IGF-1, polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP), DNA sequencing, sheep, goa