Cysteine-free peptides in scorpion venom: geographical distribution, structure-function relationship and mode of action

Scorpion venoms are well known sources of Na+-channel, K+-channel, Cl--channel, Ca2+-channel and ryanodine channel selective peptides. In 1993, the first cysteine-free peptide was isolated from scorpionvenom. Within the last six years, cysteine-free peptides with and without antimicrobial activity have been isolated from scorpion venom. The first antimicrobial peptides being parabutoporin and hadrurin, after which nine more have followed. Characteristics of these peptides include pore-formation and/or antimicrobial activity. Six peptides of similar structures without antimicrobial activity have also been isolated. Two of these peptides have bradykinin-potentiating functions. The functions of the other four are unknown. These peptides have the potential to combat cancer, a variety of skin or wound bacterial and fungal infections. This review will focus on the primary and secondary structures as well asreported functions and applications of the cysteine-free peptides identified in scorpion venom

Towards a Responsible Land Administration Curriculum

In line with the GLTN focus on strengthening land policy, improving global knowledge, and strengthening capacity of partners, the GLTN Secretariat engaged ITC (University of Twente) to explore the feasibility of the design and development of curricula in Responsible Land Administration. The general objective is to strengthen the capacity of higher education and other relevant networks or institutions globally and provide quality undergraduate and post-graduate courses on the theme of pro-poor, gender responsive land tools. In inception phase representatives from ITC and the Technical University of Munich (TUM) in consultation with GLTN secretariat, guided by the project’s general objective, developed a framework with overall approach. The main output was a curriculum design entitled ”Teaching Essentials for Responsible Land Administration” with a course title “Responsible Land Administration 101” was created and distributed for review and comments. A final report included a brief outline of a draft curriculum and recommendations for next phase/s of curriculum development. This preliminary work forms the basis for the next stage of development, which is coordinated by RMIT University and University of East London under project 2 of the GLTN Research and Training Cluster. This project aims to develop detailed outlines for each of the 6 Modules, and commence development of full curricula. Based on the original design by ITC expanded outlines for each Module have been developed and it is on these that we are seeking expert input with key stakeholders. In November 2016, an expert group meeting (EGM) was held at the University of East London. The EGM was organized by GLTN partners UN-Habitat, the University of East London and RMIT University. A total of 18 experts, from various countries and academic and professional disciplines within the land sector, discussed and agreed on next steps in the production of a structured knowledge base to support the development and delivery of the curriculum. The potential users include any land-related academic program and self-study courses with potential for certification. This EGM has established a firm foundation for the development of the structured knowledge base, which is planned for completion during 2017. Six modules are planned, including an introductory, module on responsible land administration, plus five substantial modules covering the key subject areas of access to land & land tenure security, land management & planning, land policy & regulatory frameworks, land based financing / land value sharing, and responsible land administration and information

Consumer preferences towards the marketing communication activities of non-profit organisations in Gauteng : a generational perspective

With donations declining as donors become older (Baby Boomers), non-profit organisations (NPOs) are compelled to shift their marketing focus to younger generations (Generation X and Generation Y) if they are to survive in a sector hampered by an increase in competition, a lack of funding and a shortage of volunteers. In order to address the younger generations, NPOs are required to have a better understanding of their donors’ demographic and psychographic characteristics, as this would enable them to communicate more effectively with the respective generations. As such, the purpose of this study is to measure the preferences of Baby Boomers, Generation X and Generation Y as current donors towards the marketing communication activities of NPOs. More specifically, the generations’ preferences towards the nature of marketing done by NPOs, the marketing communication elements, media channels, marketing messages and communication sources used by NPOs are measured and based on the results, a number of recommendations are suggested as to how NPOs should adapt their marketing communication strategies when addressing the different generations. Exploratory research, in the form of a secondary data analysis and five informal expert surveys, as well as descriptive research, in the form of a structured self-administered questionnaire was used to obtain the necessary data. The target population included all Baby Boomers (i.e. individuals born between 1946 and 1964), Generation X (i.e. individuals born between 1965 and 1976), and Generation Y members (i.e. individuals born between 1977 and 1994) residing in Gauteng, who had supported an NPO in the previous year and who were representative of the four major racial groups in South Africa (i.e. Black, Coloured, Indian and White). Quota sampling was used to divide the population into three quotas according to generation, while convenience sampling was used to fill each quota. In-home and intercept interviewing was used to obtain the necessary data from the respondents. In the end, the results revealed a number of similarities and differences between the three generations in terms of their preferences towards the marketing communication activities of NPOs. In terms of the generations’ preferences towards the nature of marketing done in the NPO sector, the respondents generally prefer NPOs that provide them with different options in terms of how they can support the NPO. More specific differences reveal that Generation Y, in contrast to Baby Boomers, prefers NPOs that allow them to provide feedback on their experience with the NPO. Considering the marketing communication elements that NPOs can use to convince the different generations to support them, respondents overall show preference towards making small contributions for a product purchased. More specifically Generation X and Generation Y prefer online fundraising appeals and social networks; Generation Y prefers NPOs’ websites; Generation X prefers special events and Baby Boomers show a strong preference towards articles placed in newspapers and magazines. In terms of the media channels that NPOs can use to communicate with donors, the respondents overall have a preference towards radio. In terms of specific differences between the generations, Generation Y and Generation X prefer the Internet, while Generation X prefers e-mail messages in relation to Baby Boomers, and sms messages in relation to Generation Y. As for the marketing messages used by NPOs, the respondents overall prefer the NPO’s marketing message if it is a positive one rather than a negative one. Comparing the generations, it is evident that Generation Y, compared to Baby Boomers, prefer the marketing messages of NPOs that create an emotion, that show information that will shock them, that use music which is popular to Generation Y listeners, and that contain images which attract their attention. In terms of the communication sources that NPOs might use, the respondents overall have a preference towards the NPO itself as the source – and, to a slightly lesser degree, if a beneficiary of the NPO is the source. Based on the similarities and differences between the generations, a number of specific recommendations are formulated in terms of how NPOs should communicate with the different generations, which media channels to use, the type of messages that should be conveyed and which communication source to use

A Cosine Rule-Based Discrete Sectional Curvature for Graphs

How does one generalize differential geometric constructs such as curvature of a manifold to the discrete world of graphs and other combinatorial structures? This problem carries significant importance for analyzing models of discrete spacetime in quantum gravity; inferring network geometry in network science; and manifold learning in data science. The key contribution of this paper is to introduce and validate a new estimator of discrete sectional curvature for random graphs with low metric-distortion. The latter are constructed via a specific graph sprinkling method on different manifolds with constant sectional curvature. We define a notion of metric distortion, which quantifies how well the graph metric approximates the metric of the underlying manifold. We show how graph sprinkling algorithms can be refined to produce hard annulus random geometric graphs with minimal metric distortion. We construct random geometric graphs for spheres, hyperbolic and euclidean planes; upon which we validate our curvature estimator. Numerical analysis reveals that the error of the estimated curvature diminishes as the mean metric distortion goes to zero, thus demonstrating convergence of the estimate. We also perform comparisons to other existing discrete curvature measures. Finally, we demonstrate two practical applications: (i) estimation of the earth's radius using geographical data; and (ii) sectional curvature distributions of self-similar fractals

Mangiferin: A Promising Anticancer Bioactive

Of late, several biologically active antioxidants from natural products have been investigated by the researchers in order to combat the root cause of carcinogenesis, i.e., oxidative stress. Mangiferin, a therapeutically active C-glucosylated xanthone, is extracted from pulp, peel, seed, bark and leaf of Mangifera indica. These polyphenols of mangiferin exhibit antioxidant properties and tend to decrease the oxygen-free radicals, thereby reducing the DNA damage. Indeed, its capability to modulate several key inflammatory pathways undoubtedly helps in stalling the progression of carcinogenesis. The current review article emphasizes an updated account on the patents published on the chemopreventive action of Mangiferin, apoptosis induction made on various cancer cells, along with proposed antioxidative activities and patent mapping of other important therapeutic properties. Considering it as promising polyphenol, this paper would also summarize the diverse molecular targets of Mangiferin

Density functional study of the actinide nitrides

The full potential all electron linearized augmented plane wave plus local orbitals (FP-LAPW + lo) method, as implemented in the suite of software WIEN2K, has been used to systematically investigate the structural, electronic, and magnetic properties of the actinide compounds AnN (An = Ac, Th, Pa, U, Np, Pu, Am). The theoretical formalism used is the generalized gradient approximation to density functional theory (GGA-DFT) with the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional. Each compound has been studied at six levels of theory: non-magnetic (NM), non-magnetic with spin-orbit coupling (NM+SOC), ferromagnetic (FM), ferromagnetic with spin-orbit coupling (FM+SOC), anti-ferromagnetic (AFM), and anti-ferromagnetic with spin-orbit coupling (AFM+SOC). The structural parameters, bulk moduli, densities of states, and charge distributions have been computed and compared to available experimental data and other theoretical calculations published in the literature. The total energy calculations indicate that the lowest energy structures of AcN, ThN, and PaN are degenerate at the NM+SOC, FM+SOC, and AFM+SOC levels of theory with vanishing total magnetic moments in the FM+SOC and AFM+SOC cases, making the ground states essentially non-magnetic with spin-orbit interaction. The ground states of UN, NpN, PuN, and AmN are found to be FM+SOC at the level of theory used in the present computations. The nature of the interactions between the actinide metals and nitrogen atom, and the implications on 5f electron delocalization and localization are discussed in detail.Comment: 5 tables, 12 figure

Nanostructured SnO2 films prepared from evaporated Sn and their application as gas sensors

This paper describes the morphology, stoichiometry, microstructure and gas sensing properties of nanoclustered SnOx thin films prepared by Sn evaporation followed by a rheotaxial growth and thermal oxidation process. Electron microscopy was used to investigate, in detail, the evolution of the films as the oxidation temperature was increased. The results showed that the contact angle, perpendicular height, volume and microstructure of the clusters all changed significantly as a result of the thermal oxidation processes. Electron diffraction and x-ray photoelectron spectroscopy measurements revealed that after oxidation at a temperature of 600 °C, the Sn clusters were fully transformed into porous three-dimensional polycrystalline SnO2 clusters. On the basis of these results, a prototype SnO2 sensor was fabricated and sensing measurements were performed with H2 and NO2 gases. At operating temperatures of 150-200 °C the film produced measurable responses to concentrations of H2 as low as 600 ppm and NO2 as low as 500 ppb

The use of confocal microscopy in quantifying changes in membrane potential

Monitoring the plasma membrane potential and its changes can be a time consuming and challenging task especially when conventional electrophysiological techniques are used. The use of potentiometricfluorophores, namely tetramethylrhodamine methylester (TMRM), and digital imaging devices (laser scanning confocal microscopy) provides reliable and time efficient method. Two scorpion pore-forming peptides, namely PP and OP1, were used as a tool to induce depolarization of the plasma membrane potential of neuroblastoma cell line and cardiac myocytes. Alternative methods for the neuroblastoma cells and cardiac myocytes were used. Depolarization of the neuroblastoma cells was calibrated with 140 mM KCl solution with 1 ìM valinomycin, after which intensity readers were substituted in the Nernst equation for quantification. Calibration of the alternative method used of the cardiac myocytes’ plasma membrane potential changes was calibrated with the use of 5, 20, 40, and 80 mM KCl solutions with 1 ìM valinomycin. A calibration curve was then constructed from which plasma membrane potential could be calculate