Symbiotic NCR Peptide Fragments Affect the Viability,Morphology and Biofilm Formation of Candida Species

The increasing rate of fungal infections causes global problems not only in human healthcare but agriculture as well. To combat fungal pathogens limited numbers of antifungal agents are available therefore alternative drugs are needed. Antimicrobial peptides are potent candidates because of their broad activity spectrum and their diverse mode of actions. The model legume Medicago truncatula produces >700 nodule specific cysteine-rich (NCR) peptides in symbiosis and many of them have in vitro antimicrobial activities without considerable toxicity on human cells. In this work we demonstrate the anticandidal activity of the NCR335 and NCR169 peptide derivatives against five Candida species by using the micro-dilution method, measuring inhibition of biofilm formation with the XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) assay, and assessing the morphological change of dimorphic Candida species by microscopy. We show that both the N- and C-terminal regions of NCR335 possess anticandidal activity as well as the C-terminal sequence of NCR169. The active peptides inhibit biofilm formation and the yeast-hypha transformation. Combined treatment of C. auris with peptides and fluconazole revealed synergistic interactions and reduced 2-8-fold the minimal inhibitory concentrations. Our results demonstrate that shortening NCR peptides can even enhance and broaden their anticandidal activity and therapeutic potential.     

The Protein Phosphatase PP2A Plays Multiple Roles in Plant Development by Regulation of Vesicle Traffic—Facts and Questions

The protein phosphatase PP2A is essential for the control of integrated eukaryotic cell functioning. Several cellular and developmental events, e.g., plant growth regulator (PGR) mediated signaling pathways are regulated by reversible phosphorylation of vesicle traffic proteins. Reviewing present knowledge on the relevant role of PP2A is timely. We discuss three aspects: (1) PP2A regulates microtubule-mediated vesicle delivery during cell plate assembly. PP2A dephosphorylates members of the microtubule associated protein family MAP65, promoting their binding to microtubules. Regulation of phosphatase activity leads to changes in microtubule organization, which affects vesicle traffic towards cell plate and vesicle fusion to build the new cell wall between dividing cells. (2) PP2A-mediated inhibition of target of rapamycin complex (TORC) dependent signaling pathways contributes to autophagy and this has possible connections to the brassinosteroid signaling pathway. (3) Transcytosis of vesicles transporting PIN auxin efflux carriers. PP2A regulates vesicle localization and recycling of PINs related to GNOM (a GTP–GDP exchange factor) mediated pathways. The proper intracellular traffic of PINs is essential for auxin distribution in the plant body, thus in whole plant development. Overall, PP2A has essential roles in membrane interactions of plant cell and it is crucial for plant development and stress responses.     

The role of South African researchers in intercontinental collaboration

Scientometrics - The analysis presented here focuses on mapping, based on publication output, the scientific collaboration of African based researchers and the role of the South African research...     

Treatments of Lignocellulosic Hydrolysates and Continuous‐Flow Hydrogenation of Xylose to Xylitol

Xylitol is produced by the heterogeneous catalytic hydrogenation of xylose over Raney nickel. The hydrogenation must typically be followed by several purification steps, which makes the chemical production relatively complex and expensive. In this study, activated carbon and bio‐purification treatments of corn stover hydrolysates and subsequent nickel‐catalyzed hydrogenation of xylose to xylitol were investigated. The activated carbon treatment was used to eliminate inhibitory compounds and increase the efficiency of the bio‐purification step. It was found that the glucose could be completely eliminated from the hydrolysate. The hydrogenation reactions of corn stover hydrolysate demonstrated that a high reaction temperature resulted in high sugar alcohol yields and selectivity. At a given temperature, the flow rate had no significant effect on xylitol yield.     

Running repeatable and controlled virtual routing experiments

This paper describes an approach to perform reproducible performance tests on virtual routers, comparing different virtual routing architectures, different software versions and configurations. The presented approach is based on VRKit, a software tool that allows to build pre‐configured bootable virtual router images with the desired characteristics. Design decisions are described, and some usage examples are presented, showing how the tool can be used for research on virtual routing, facilitating performance comparison of various virtual router implementations. Copyright © 2013 John Wiley & Sons, Ltd.     

Dielectric Response of Embedded Fullerenes: A Classical Approach

The optical properties of fullerenes embedded in other media is explored, assuming that a single fullerene behaves as a microscopic crystallite. The justification for this assumption is discussed, and various experimental results are compared to test the limits of this approximation. The effective medium theory is used to calculate the optical response of exemplary composite systems.