472 research outputs found
The north-eastern aeolian 'European Sand Belt' as potential record of environmental changes: A case study from Eastern Latvia and Southern Estonia
The Latvian and Estonian inland dunes belong to the north-eastern part of the 'European Sand Belt' (ESB). These dunes are widely distributed over broad glaciolacustrine plains and Late Glacial alluvial deltas, considered to be potential sources for the aeolian material. Little is known about these aeolian sediments and their substratum; here we present a detailed sedimentary structural and textural characterisation together with a luminescence-based chronology. Through a comparison between grain-size, rounding of quartz grains and surface characteristics in medium/coarse (0.5-0.8 mm) sand, and the light mineral content, we found an alternation of aeolian and periglacial components. Further, short-lasting aeolian abrasion and/or transportation periods, and a significant contribution of a nearby sediment source are suggested. Luminescence dating points to aeolian sand accumulation and dune formation between ~16 ka and ~9 ka. However, we also observed some presumably watertable controlled environmental conditions at ~13 ka; this corresponds with the occurrence of an ice-dammed/proglacial lake
Potential of a cyclone prototype spacer to improve in vitro dry powder delivery
Copyright The Author(s) 2013. This article is published with open access at Springerlink.com. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPurpose: Low inspiratory force in patients with lung disease is associated with poor deagglomeration and high throat deposition when using dry powder inhalers (DPIs). The potential of two reverse flow cyclone prototypes as spacers for commercial carrierbased DPIs was investigated. Methods: Cyclohaler®, Accuhaler® and Easyhaler® were tested with and without the spacers between 30-60 Lmin-1. Deposition of particles in the next generation impactor and within the devices was determined by high performance liquid chromatography. Results: Reduced induction port deposition of the emitted particles from the cyclones was observed due to the high retention of the drug within the spacers (e.g. salbutamol sulphate (SS): 67.89 ± 6.51 % at 30 Lmin-1 in Cheng 1). Fine particle fractions of aerosol as emitted from the cyclones were substantially higher than the DPIs alone. Moreover, the aerodynamic diameters of particles emitted from the cyclones were halved compared to the DPIs alone (e.g. SS from the Cyclohaler® at 4 kPa: 1.08 ± 0.05 μm vs. 3.00 ± 0.12 μm, with and without Cheng 2, respectively) and unaltered with increased flow rates. Conclusion: This work has shown the potential of employing a cyclone spacer for commercial carrier-based DPIs to improve inhaled drug delivery.Peer reviewe
Influence of dietary conjugated linoleic acid (CLA) and tetradecylthioacetic acid (TTA) on growth, lipid composition and key enzymes of fatty acid oxidation in liver and muscle of Atlantic cod (Gadus morhua L.)
The aim of the present study was to determine the effects of conjugated linoleic acid (CLA) and tetradecylthioacetic acid (TTA) on growth performance, and lipid and fatty acid metabolism in Atlantic cod. The overall objective being to test the hypotheses that CLA and TTA have beneficial effects in cod culture including decreased liver size and proportion through decreased lipid content, and increased nutritional quality through effects on fatty acid compositions including accumulation of bioactive fatty acids, CLA and TTA, in flesh. Juvenile cod were fed for three months on fish meal and fish oil diets of basically commercial formulation, but containing either 0.5% or 1% CLA, or 0.5% TTA. The effects of the functional fatty acids on growth, feed efficiency, body proximate composition, liver weight and lipid composition, fatty acid compositions of flesh and liver, and key enzymes of fatty acid oxidation were determined. Dietary CLA and TTA had no effect on growth parameters in cod juveniles, but viscero- and hepato-somatic indices were increased in fish fed 0.5% CLA and TTA, respectively. Proximate composition of whole fish was not affected by CLA or TTA, and there were no major effects of either functional fatty acid on lipid contents and compositions of liver and flesh. Dietary CLA and TTA were both incorporated into tissue lipids, with CLA deposited to a greater extent in liver, whereas TTA was deposited to a greater extent in flesh. In liver, acyl CoA oxidase (ACO) activity, but not carnitine palmitoyltransferase-I (CPT-I), was increased by CLA, whereas dietary TTA increased both ACO and CPT-I activities. In contrast, ACO activity was reduced by both CLA and TTA in red and white muscle, whereas CPT-I activity was generally not affected by CLA and TTA in either muscle tissue. Therefore, the results only partially supported the hypotheses tested, as CLA and TTA had few beneficial effects in Atlantic cod and did not enhance growth parameters, or improve feed conversion or potential yield through decreased adiposity or liver lipid deposition. However, nutritional quality could be enhanced, and cod fed CLA and/or TTA could be beneficial in the human diet, through provision of bioactive fatty acids with no detrimental effects on n-3 PUFA levels
Individual Preferences and Social Interactions Determine the Aggregation of Woodlice
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