The excretion of urea by the larvae ofSpodoptera mauritia boisd. (Noctuidae: Lepidoptera) during development

Summary The concentration of urea in the excreta of the 6th instar larvae ofSpodoptera mauritiavaries from 4.017±0.541 to 31.052±1.193 moles/g dry excreta (mean±SE). The observation confirms that urea excreted is of metabolic origin.     

IL-21 initiates an alternative pathway to induce proinflammatory T(H)17 cells

On activation, naive T cells differentiate into effector T-cell subsets with specific cytokine phenotypes and specialized effector functions. Recently a subset of T cells, distinct from T helper (T(H))1 and T(H)2 cells, producing interleukin (IL)-17 (T(H)17) was defined and seems to have a crucial role in mediating autoimmunity and inducing tissue inflammation. We and others have shown that transforming growth factor (TGF)-beta and IL-6 together induce the differentiation of T(H)17 cells, in which IL-6 has a pivotal function in dictating whether T cells differentiate into Foxp3+ regulatory T cells (T(reg) cells) or T(H)17 cells. Whereas TGF-beta induces Foxp3 and generates T(reg) cells, IL-6 inhibits the generation of T(reg) cells and induces the production of IL-17, suggesting a reciprocal developmental pathway for T(H)17 and T(reg) cells. Here we show that IL-6-deficient (Il6-/-) mice do not develop a T(H)17 response and their peripheral repertoire is dominated by Foxp3+ T(reg) cells. However, deletion of T(reg) cells leads to the reappearance of T(H)17 cells in Il6-/- mice, suggesting an additional pathway by which T(H)17 cells might be generated in vivo. We show that an IL-2 cytokine family member, IL-21, cooperates with TGF-beta to induce T(H)17 cells in naive Il6-/- T cells and that IL-21-receptor-deficient T cells are defective in generating a T(H)17 response.     

Elaboration of AlSi10Mg casting alloys using directional solidification processing

The effects of pulling velocity on the solidification behavior and microstructural parameters of AlSi10Mg alloys prepared in a Bridgman-type directional solidification furnace were investigated. The microstructure, particularly the secondary dendritic arm spacing (SDAS), and the Brinell hardness (BH) of the solidified AlSi10Mg alloys were characterized for samples with cylindrical shapes and different conicities (θ=0°, 5°, and 10°). Microstructural studies revealed an increased density of α-Al phase dendrites and a decreased interdendritic distance with increasing pulling velocity. The dendrites were found to be preferentially oriented along the pulling direction for low pulling velocities. For larger pulling velocities, the dendrites grew first in the cooling direction but then broke as others nucleated and coarsened. The HB values of the solidified samples increased as the pulling velocity increased. In regard to sample conicity, smaller dendrites were observed for an apex angle of θ=5°, resulting in the largest HB value. This result was interpreted in terms of the favorable orientation of the dendrite along the pulling direction.     

Martensitic transformation and magnetic properties of aged Ni-Fe-Ga-Ti shape memory alloy

This article reports the effect of ageing on the microstructure, martensitic transformation, magnetic properties, and mechanical properties of Ni₅₁Fe₁₈Ga₂₇Ti₄ shape memory alloy. There are five specimens of this alloy aged at 573 up to 973 K for 3 h per each. This range of ageing temperature greatly affects the microstructure of the alloy. As the ageing temperature increased from 573 up to 973 K, the microstructure of Ni₅₁Fe₁₈Ga₂₇Ti₄ alloy gradually changed from the entirely martensitic matrix at 573 K to the fully austenitic microstructure at 973 K. The volume fraction of precipitated Ni₃Ti particles increased with the ageing temperature increasing from 573 to 773 K. Further increasing the ageing temperature to 973 K decreased the content of Ni₃Ti in the microstructure. The martensitic transformation temperature was decreased steadily by increasing the ageing temperature. The magnetization saturation, remnant magnetization, and coercivity increased with the ageing temperature increasing up to 773 K. A further increase in ageing temperature decreased these magnetic properties. Moreover, the hardness values were gradually increased at first by increasing the ageing temperature to 773 K, and then dramatically decreased to the lowest value at 973 K.     

A contribution to the knowledge of fly fauna in the Kingdom of Saudi Arabia: new country records and an account of flies identified from Rawdhats,Riyadh Region,with biogeographical remarks (Insecta: Diptera)

A total of 80 fly species (Insecta: Diptera) belonging to 66 genera, and representing 26 families was identified from three natural areas or ‘Rawdhats’ in the Riyadh Region of the Kingdom of Saudi Arabia (KSA). The Rawdhats surveyed are Al-Harmaliyah (Al Quwayiyah Province), Al-Sabalah (Azulfi Province) and Farshet Sheaal (Al Aflaj Province). One family, one subfamily, 11 genera and 18 species were recorded for the first time from KSA, namely: the family Trixoscelididae; the subfamily Suilliinae (Heleomyzidae); the genera Oligodranes (Bombyliidae), Pseudomphrale (Scenopinidae), Actorthia (Therevidae), Crossopalpus (Hybotidae), Scatella (Ephydridae), Suillia (Heleomyzidae), Trixoscelis (Trixoscelididae), Renocera [Sciomyzidae], Melanophora and Stevenia [Rhinophoridae], Miltogramma [Sarcophagidae]; and the species Eremisca heleni (Efflatoun) and Ommatius tenellus van der Wulp [Asilidae], Oligodranes sp. [Bombyliidae], Pseudomphrale flavoscutellata Kröber [Scenopinidae], Actorthia lacteipennis (Becker), Actorthia sp. and Efflatouniella sinatica Mohammad and Badrawy [Therevidae], Crossopalpus hirsutipes Collin [Hybotidae], Eumerus mucidus Bezzi [Syrphidae], Ephydra riparia Fallén and Scatella sp. [Ephydridae], Suillia apicalis (Loew) [Heleomyzidae], Trixoscelis sp. (Trixoscelididae) and Renocera pallida (Fallén) [Sciomyzidae], Goniurellia longicauda Freidberg [Tephritidae], Melanophora sp. and Stevenia sp. [Rhinophoridae], and Miltogramma sp. [Sarcophagidae]. The zoogeographic affinities of the identified species showed a closer affiliation with the Palaearctic Region (26%) than to the Afrotropical Region (12.5%), while about 16% of the species were of both Afrotropical and Palaearctic affinities. Elements from other regions were apparently absent. The result support the idea that the central Arabian Desert which includes our study area is a transitional zone between the Palaearctic and Afrotropical regions.     

Mutations in sodium-borate cotransporter SLC4A11 cause recessive congenital hereditary endothelial dystrophy (CHED2)

Congenital hereditary endothelial dystrophy (CHED) is a heritable, bilateral corneal dystrophy characterized by corneal opacification and nystagmus. We describe seven different mutations in the SLC4A11 gene in ten families with autosomal recessive CHED. Mutations in SLC4A11, which encodes a membrane-bound sodium-borate cotransporter, cause loss of function of the protein either by blocking its membrane targeting or nonsense-mediated decay.     

Electroless copper-phosphorus coatings with the addition of silicon carbide (SiC) particles

Cu-P-silicon carbide (SiC) composite coatings were deposited by means of electroless plating. The effects of pH values, temperature, and different concentrations of sodium hypophosphite (NaH₂PO₂·H₂O), nickel sulfate (NiSO₄·6H₂O), sodium citrate (C₆H₅Na₃O₇·2H₂O) and SiC on the deposition rate and coating compositions were evaluated, and the bath formulation for Cu-P-SiC composite coatings was optimised. The coating compositions were determined using energy-dispersive X-ray analysis (EDX). The corresponding optimal operating parameters for depositing Cu-P-SiC are as follows: pH 9; temperature, 90℃; NaH₂PO₂·H₂O concentration, 125 g/L; NiSO₄·6H₂O concentration, 3.125 g/L; SiC concentration, 5 g/L; and C₆H₅Na₃O₇·2H₂O concentration, 50 g/L. The surface morphology of the coatings analysed by scanning electron microscopy (SEM) shows that Cu particles are uniformly distributed. The hardness and wear resistance of Cu-P composite coatings are improved with the addition of SiC particles and increase with the increase of SiC content.     

The Critical Heuristics of Iranian Banking Credit System: Analysis of the Antithetical Opinions of the Beneficiaries

Systemic Practice and Action Research - Considering the unfortunate intensification of the Non-performing loans in Iran`s credits system makes it vital to study the current system shortcomings....