Origin,metabolism, and adverse health effects of cholesterol oxidation products

Cholesterol oxidation products (COP), also called oxysterols, enter the organism by intake of COP-containing foodstuff or are generated in vivo by enzymatic or non-enzymatic oxidation (peroxidation) of cholesterol. COP are transported in lymph and blood with lipoproteins (mainly fatty acyl monoesters at the 3β-position) or bound to albumin. As being substrates for acyl CoA: cholesterol acyltransferase (ACAT), lecithin:cholesterol acyltransferase (LCAT), and cholesteryl ester transfer protein (CETP), COP are esterified and exchanged between lipoproteins and are distributed in the whole organism. Kupffer cells and hepatocytes are the target cells for COP transformation and excretion via bile secretion. Regarding biological activities, COP reveal widespread effects on cholesterol metabolism as well as on structure and function of cellular membranes. Throughout their actions, COP were shown to be cytotoxic but they were also suggested to be regulatory agents. Their detrimental part in atherogenesis seems to be still underestimated, while valid data on the role of COP in carcinogenesis are still missing.     

Lessons Learned from the Studies of Roots Shaded from Direct Root Illumination

The root is the below-ground organ of a plant, and it has evolved multiple signaling pathways that allow adaptation of architecture, growth rate, and direction to an ever-changing environment. Roots grow along the gravitropic vector towards beneficial areas in the soil to provide the plant with proper nutrients to ensure its survival and productivity. In addition, roots have developed escape mechanisms to avoid adverse environments, which include direct illumination. Standard laboratory growth conditions for basic research of plant development and stress adaptation include growing seedlings in Petri dishes on medium with roots exposed to light. Several studies have shown that direct illumination of roots alters their morphology, cellular and biochemical responses, which results in reduced nutrient uptake and adaptability upon additive stress stimuli. In this review, we summarize recent methods that allow the study of shaded roots under controlled laboratory conditions and discuss the observed changes in the results depending on the root illumination status.     

Concept keyboards in the animation of standard algorithms

Software visualization and algorithm animation have been tackled almost exclusively from the visual point of view; this means representation and control occur through the visual channel. This approach has its limitations. To achieve better comprehension, we deal with multimodal interfaces that include the extended facilities of interaction together with those of the standard systems for data visualization and algorithm animation. The notion of specific concept keyboards is introduced. As a consequence, modern information and learning systems for algorithm animation are enhanced in such a way that control and interaction take place through appropriate interfaces designed and semi-automatically generated for this special purpose. In this paper, we provide some examples and report on a thorough evaluation to show the relevance of this new approach.     

A Probabilistic Approach to Concurrent Mapping and Localization for Mobile Robots

This paper addresses the problem of building large-scale geometric maps of indoor environments with mobile robots. It poses the map building problem as a constrained, probabilistic maximum-likelihood estimation problem. It then devises a practical algorithm for generating the most likely map from data, along with the most likely path taken by the robot. Experimental results in cyclic environments of size up to 80×25 m illustrate the appropriateness of the approach.