Evaluation of the cytotoxic and genotoxic potential of Khat (Catha edulis Forsk) extracts on human T lymphoblastoid cell line

This paper reports on an investigation of the cytotoxic and genotoxic potential of khat extract using a human T lymphoblastoid cell line (CEM). Exponentially growing CEM cells were cultured for 12 h in the presence of khat extract (0-2000 μg ml-1). Statistically significant, dose-dependent increases in; CEM cell death at dose (> 400 μg ml-1), in DNA damage at dose (>200 μg ml-1) and in micronuclei frequency, at dose (>200 μg ml-1) were observed. The genetic damage effects of khat extract on human cell line observed in this study could serve as a major contribution towards the understanding and creating of awareness of an increased risk of cancer amongst long-term khat consumers

Assessing the role of mini-applications in predicting key performance characteristics of scientific and engineering applications

Computational science and engineering application programs are typically large, complex, and dynamic, and are often constrained by distribution limitations. As a means of making tractable rapid explorations of scientific and engineering application programs in the context of new, emerging, and future computing architectures, a suite of "miniapps" has been created to serve as proxies for full scale applications. Each miniapp is designed to represent a key performance characteristic that does or is expected to significantly impact the runtime performance of an application program. In this paper we introduce a methodology for assessing the ability of these miniapps to effectively represent these performance issues. We applied this methodology to three miniapps, examining the linkage between them and an application they are intended to represent. Herein we evaluate the fidelity of that linkage. This work represents the initial steps required to begin to answer the question, "Under what conditions does a miniapp represent a key performance characteristic in a full app?

Cyanogenic potential in food crops and its implication in cassava ( Manihot esculenta Crantz) production

Cyanide a by-product from cyanogenic glucosides is toxic to humans and most living organisms due to its ability of binding to metals such as iron, zinc and copper functional groups of the ligands of most bio enzymes. The cyanide inhibits the reduction of oxygen in the respiratory electron transfer system, the inhibition of plastocyanin reduction in photosynthesis and catalase activity. The magnitude of cyanide metabolism varies greatly between different plant species. Although most plant species produce small amount of cyanide associated with ethylene production, between 3-12000 plant species produce sufficient amounts of cyanogenic compounds that they may function as translocatable forms of reduced nitrogen or as chemical defense molecules against pests and diseases. This paper discusses the cyanogenic potential (ability to produce hydrogen cyanide), in food crops, the importance of cassava as a cyanogenic food crop, cyanide toxicity, metabolism, the enzyme activities of linamarases ( -glucosidase), hydroxyl nitrile lyase, and cyanide detoxification processes