Efficacy of urea spray for wheat crop under irrigated conditions in Iraq

Summary Effects of varying levels of nitrogenviz 40, 80 and 120 kg/ha and two methods of applicationviz (1) Soil application; and (2) one half applied to the soil and the other half to the plant foliage, were studied on growth and yield of wheat crop. Results showed that foliar feeding of urea in combination with soil application to wheat crop gave significant increases in their grain yields. Thus there is a great scope of utilizing this technique for increasing grain yields of wheat and other cereal crops grown in Iraq.     

Isolation and culture of protoplasts ofCapsicum annuum L. and their regeneration into plants floweringin vitro

Summary Axenic shoot cultures ofCapsicum annuum cv.California Wonder were used as the source for isolation of protoplasts from mesophyll cells. Protoplasts underwent sustained mitotic activity and proliferated to form callus masses on NT or DPD medium enriched with 2,4-D, NAA and BAP each at 1 mg/l level. The callus could be differentiated into whole plants on the differentiation media and plants floweredin vitro under long day conditions.     

Cluster mechanism for sensing data report using robust collaborative distributed spectrum sensing

Cluster Computing - In cooperative mobile communications, spectrum sensing performance may encounter difficulties, which alert with many reporting errors, especially in dense network scenarios. In...     

The location of structural difference between ovotransferrin types A and B in hens

A comparison of ovotransferrin types A and B showed that in starch gel electrophoresis both types consisted of one major and one minor component. Both types have a similar amino acid composition as do the fragments from each type. Starch gel electrophoresis shows that the cause of the difference in the elec-trophoretic mobilities between ovotransferrin types A and B lies in the C-termi-nal half of the molecule. No physiological difference was found between types A and B, both types donate iron to chicken embryo red cells at equal rate.     

An atypical BRCT–BRCT interaction with the XRCC1 scaffold protein compacts human DNA Ligase IIIα within a flexible DNA repair complex

The XRCC1–DNA ligase IIIα complex (XL) is critical for DNA single-strand break repair, a key target for PARP inhibitors in cancer cells deficient in homologous recombination. Here, we combined biophysical approaches to gain insights into the shape and conformational flexibility of the XL as well as XRCC1 and DNA ligase IIIα (LigIIIα) alone. Structurally-guided mutational analyses based on the crystal structure of the human BRCT–BRCT heterodimer identified the network of salt bridges that together with the N-terminal extension of the XRCC1 C-terminal BRCT domain constitute the XL molecular interface. Coupling size exclusion chromatography with small angle X-ray scattering and multiangle light scattering (SEC-SAXS–MALS), we determined that the XL is more compact than either XRCC1 or LigIIIα, both of which form transient homodimers and are highly disordered. The reduced disorder and flexibility allowed us to build models of XL particles visualized by negative stain electron microscopy that predict close spatial organization between the LigIIIα catalytic core and both BRCT domains of XRCC1. Together our results identify an atypical BRCT–BRCT interaction as the stable nucleating core of the XL that links the flexible nick sensing and catalytic domains of LigIIIα to other protein partners of the flexible XRCC1 scaffold.     

Pollen dimorphism in relation to pollen plant formation

Induction of haploid plants from pollen grains on culture of anthers has been possible in a number of angiosperms but it is not yet understood why only a fraction of pollen responds to form haploids. Noteworthy in this connection are the recent experiments on anther culture of barley, tobacco and wheat, where it has been pointed out that pollen populations are basically dimorphic. Pollen capable of forming haploids occur in a low frequency, arc smaller, and different from the majority of pollen destined to form gametes. Particularly in tobacco it has been possible to increase the frequency of pollen capable of forming embryos by subjecting plants to low temperature prior to flowering, and to achieve differentiation of embryogenic pollen by subjecting young buds from such plants to a prolonged cold treatment. On selective isolation, from the rest of the pollen, the embryogenic pollen from such buds readily form embryos at high frequency on a simple mineral-sucrose medium. The embryogenic pollen are repressed for gametophytic differentiation and in culture they differentiate to produce embryos. These experiments provide evidence that only certain pollen are capable of forming haploids.