Abrasive and impact wear of stone used to manufacture axes in Neolithic Greece

Excavations at the Neolithic settlement at Makriyalos in Northern Greece brought to light a large number of stone axe heads, the majority of which were manufactured from serpentinite and igneous rocks. Detailed study of the manufacturing traces on the archaeological implements identified that both percussive (pecking) and abrasive techniques (sawing and grinding/polishing) were employed for the production of the axes. There is limited evidence, however, of how these processes may have been undertaken. The aim of this work was to build on previous research investigating sawing and polishing methods and the materials that may have been used in these tasks. Modern samples of two types of serpentinite and a dolerite were collected from the environs of the archaeological site. These were tested for strength and porosity. Through archaeological research the materials available to Neolithic people were established and some testing was carried out to establish sliding speeds and loads and percussive impact velocities achievable by a human to feed into the tribological test design. Pin-on-disc wear tests were carried out using quartz, chalcedony and sandstone as the pin material in wet and dry conditions to study sawing and polishing behaviour. Reciprocating tests were carried out using leather and combinations of lubricant (animal fat and water) and abrasive medium (sand) to study effects on polishing. Percussive impact tests were also carried out. The tests indicated that with certain combinations of materials and test conditions, both sawing and polishing could be achieved. A series of stages for the polishing were identified which are in line with observations made by archaeologists. (C) 2011 Elsevier B.V. All rights reserved

Effects of dietary monounsaturated fatty acids on lipoprotein concentrations, compositions, and subfraction distributions and on VLDL apolipoprotein B kinetics: dose-dependent effects on LDL

<p><b>Background</b>: Replacing dietary saturated fatty acids (SFAs) with monounsaturated fatty acids (MUFAs) lowers LDL cholesterol, but the underlying mechanisms remain unclear.</p> <p><b>Objective</b>: We assessed the effects of replacing dietary SFAs with MUFAs on concentrations and subclass distributions of VLDL, intermediate-density lipoprotein, LDL, and HDL and on VLDL apolipoprotein B kinetics.</p> <p><b>Design</b>: Thirty-five moderately hypercholesterolemic, middle-aged volunteers consumed for 6 wk, in random order, diets containing low (L-MUFA; 7.8% of energy from MUFAs), moderate (M-MUFA; 10.3% from MUFAs), or high (H-MUFA; 13.7% from MUFAs) amounts of MUFAs. Fasting blood samples were taken from all subjects after each intervention. VLDL apolipoprotein B kinetic studies were performed in a subgroup after the L-MUFA and H-MUFA diets.</p> <p><b>Results</b>: Plasma cholesterol concentrations decreased in a dose-dependent manner with increasing intakes of dietary MUFAs. This change was entirely accounted for by reduced LDL cholesterol (-0.20 and -0.49 mmol/L after the M-MUFA and H-MUFA diets, respectively, compared with the concentration after the L-MUFA diet; P for trend < 0.01). Plasma triacylglycerol and HDL cholesterol were not significantly affected by the dietary intervention, nor were the concentrations of VLDL1 (Sf 60–400), VLDL2 (Sf 20–60), or intermediate-density lipoprotein (Sf 12–20). Production and catabolic rates for VLDL1 and VLDL2 were also unaffected. HDL and LDL subclass distributions were not significantly altered, but as a consequence of the overall LDL lowering, concentrations of atherogenic LDL-III were 25% lower after the H-MUFA diet than after the L-MUFA diet (P = 0.02).</p> <p><b>Conclusion</b>: The effects of replacing dietary SFAs with MUFAs on lipoprotein metabolism appear to be almost exclusively limited to the LDL density class.</p&gt

Histopathological Methods for the Investigation of Microbial Communities Associated with Disease Lesions in Reef Corals

Aims: To determine the spatial structure of microbial communities associated with disease lesions of reef corals (Scleractinia). Methods and Results: Agarose pre-embedding preserved the structure of the disease lesion and surrounding tissues prior to demineralization of the carbonate exoskeleton and embedding in resin. Fluorescence in situ hybridization (FISH) was used to localize bacteria in the lesions of various diseases. Conclusions: The techniques successfully preserved the in situ spatial structure of degenerated coral tissues. In one case (white plague disease), significant bacterial populations were found only in fragmented remnants of degenerated coral tissues at the lesion boundary that would not have been detected using conventional histopathological techniques. Significance and Impact of the Study: Determining the composition, spatial structure and dynamics of microbial communities within the disease lesions is necessary to understand the process of disease progression. The methods described may be applicable to a wide range of diseases involving necrotic lesion formation and requiring extensive tissue processing, such as skeleton demineralization

European Crohn's and Colitis Organisation topical review on transitional care in inflammatory bowel disease

Background: This European Crohn's and Colitis Organisation [ECCO] topical review focuses on the transition of adolescents with inflammatory bowel disease [IBD] from child-centred to adult-oriented care. The aim was to provide evidence-supported, expert consensus for health professionals taking part in the transition. Methods: An online survey determined the areas of importance for health professionals involved in the transition of adolescents with IBD. Thereafter an expert panel of nine paediatric and five adult gastroenterologists was formed to identify the critical elements of the transition programme, and to prepare core messages defined as 'current practice points'. There is limited literature about transition, therefore this review is mainly based on expert opinion and consensus, rather than on specific evidence. Results: A total of 21 practice points were generated before the first [online] voting round. Practice points that reached > 80% agreement were accepted, while those that did not reach 80% agreement were refined during a consensus meeting and subjected to voting. Ultimately, 14 practice points were retained by this review. Conclusion: We present a consensus-based framework for transitional care in IBD that provides a guidance for clinical practice. © 2017 European Crohn's and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved