| 311. |
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| 312. |
- Brackmann, Christian, et al.
(författare)
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Simultaneous vibrational and pure rotational coherent anti-Stokes Raman spectroscopy for temperature and multispecies concentration measurements demonstrated in sooting flames
- 2002
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Ingår i: Applied Optics. - 2155-3165. ; 41:3, s. 564-572
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Tidskriftsartikel (refereegranskat)abstract
- The potential of measuring temperature and multiple species concentrations (N-2, O-2, CO) by use of combined vibrational coherent anti-Stokes Raman spectroscopy (CARS) and pure rotational CARS has been investigated. This was achieved with only one Nd:YAG laser and one dye laser together with a single spectrograph and CCD camera. From measurements in premixed sooting C2H4-air flames it was possible to evaluate temperatures from both vibrational CARS and rotational CARS, spectra, O-2 concentration from the rotational CARS spectra, and CO concentration from the vibrational CARS spectra. Quantitative results from premixed sooting C2H4-air flames are presented, and the uncertainties in the results as well as the possibility of extending the combined CARS technique fur probing of additional species are discussed. (C) 2002 Optical Society of America.
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| 313. |
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| 314. |
- Breitholtz, M., et al.
(författare)
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Ten challenges for improved ecotoxicological testing in environmental risk assessment
- 2006
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513 .- 1090-2414. ; 63:2, s. 324-335
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Forskningsöversikt (refereegranskat)abstract
- New regulations, in particular the new European chemicals legislation (REACH), will increase the demands on environmental risk assessment (ERA). The requirements on efficient ecotoxicological testing systems are summarized, and 10 major issues for the improvement of ERA practices are discussed, namely: (1) the choice of representative test species, (2) the development of test systems that are relevant for ecosystems in different parts of the world, (3) the inclusion of sensitive life stages in test systems, (4) the inclusion of endpoints on genetic variation in populations, (5) using mechanistic understanding of toxic effects to develop more informative and efficient test systems, (6) studying disruption in invertebrate endocrine mechanisms, that may differ radically from those we know from vertebrates, (7) developing standardized methodologies for testing of poorly water-soluble substances, (8) taking ethical considerations into account, in particular by reducing the use of vertebrates in ecotoxico logical tests, (9) using a systematic (statistical) approach in combination with mechanistic knowledge to combine tests efficiently into testing systems, and (10) developing ERA so that it provides the information needed for precautionary decision-making.
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| 315. |
- Brorsson, Sofia, et al.
(författare)
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Maximal strength in one leg squat correlates with acceleration capacity and agility
- 2010
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Konferensbidrag (refereegranskat)abstract
- INTRODUCTION: In many intermittent team sports capacities such as speed, agility and explosiveness are important for performance and are evaluated by sprint-, agility- and strength tests. Earlier studies have shown strong correlations between strength in the two leg squat exercise and sprint performance in various distances but not in sprint performance in agility. Studies evaluating squat strength predominantly perform tests on two legs even when they test athletes involved in intermittent sports where sprinting and agility are common features. Thus, the purpose of this study was to investigate the correlation between maximal strength in a one leg squat (Bulgarian split squat) and acceleration capacity in various sprint distances and agility.METHODS: The test group consisted of 19 men (mean age 24 ± 2 years ) with experience in intermittent team sports. Acceleration capacity was assessed by sprint tests at 5, 10 and 20 meters and agility was evaluated using the zigzag agility test. The timing was made using photocells (Muscle lab,Ergotest Technology,Norway). The Bulgarian split squat was performed in a smith machine with the barbell on the shoulders to a depth of 110 degrees between tibia and femur.RESULTS: The results show significant correlation between maximal strength in the Bulgarian split squat and sprint capacity in the 5 and 10 meter sprint test (Rp= -0,56; p<0.01) as well as the agility test. Maximal strength relative to bodyweight showed significant correlation with the 5 and 20 meter sprint (Rp=-0,62; p< 0,01) as well as the agility test. The zigzag agility test also showed significant correlation between all distances in the sprint tests (p<0.01).CONCLUSION: The results from this study show that there maximal strength in one leg correlate significantly with both acceleration capacity and agility. Implementing one leg exercises in the strength and conditioning routine can be useful for athletes in intermittent sports wanting to improve agility and short sprinting capacity. Further implications is that the Bulgarian split squat could be a more functional test for agility performance than the squat on two legs which predominantly is being used today.
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| 316. |
- Browning, Kathryn L., et al.
(författare)
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Human Lipoproteins at Model Cell Membranes : Effect of Lipoprotein Class on Lipid Exchange
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- High and low density lipoproteins (HDL and LDL) are thought to play vital roles in the onset and development of atherosclerosis; the biggest killer in the western world. Key issues of initial lipoprotein (LP) interactions at cellular membranes need to be addressed including LP deposition and lipid exchange. Here we present a protocol for monitoring the in situ kinetics of lipoprotein deposition and lipid exchange/removal at model cellular membranes using the non-invasive, surface sensitive methods of neutron reflection and quartz crystal microbalance with dissipation. For neutron reflection, lipid exchange and lipid removal can be distinguished thanks to the combined use of hydrogenated and tail-deuterated lipids. Both HDL and LDL remove lipids from the bilayer and deposit hydrogenated material into the lipid bilayer, however, the extent of removal and exchange depends on LP type. These results support the notion of HDL acting as the 'good' cholesterol, removing lipid material from lipid-loaded cells, whereas LDL acts as the 'bad' cholesterol, depositing lipid material into the vascular wall.
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| 317. |
- Browning, T. K., et al.
(författare)
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Human lipoproteins at model cell membranes : Role of the lipoprotein class on lipid dynamics
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- High and low density lipoproteins (HDL and LDL) are thought to play vital roles in the onset and development of atherosclerosis; the biggest killer in the western world. Key issues of initial lipoprotein (LP) interactions at cellular membranes need to be addressed including LP deposition and lipid exchange. Here we present a protocol for monitoring the in situ kinetics of lipoprotein deposition and lipid exchange/removal at model cellular membranes using the non-invasive, surface sensitive methods of neutron reflection and quartz crystal microbalance with dissipation. For neutron reflection, lipid exchange and lipid removal can be distinguished thanks to the combined use of hydrogenated and tail-deuterated lipids. Both HDL and LDL remove lipids from the bilayer and deposit hydrogenated material into the lipid bilayer, however, the extent of removal and exchange depends on LP type. These results support the notion of HDL acting as the ‘good’ cholesterol, removing lipid material from lipid-loaded cells, whereas LDL acts as the ‘bad’ cholesterol, depositing lipid material into the vascular wall.
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| 318. |
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| 319. |
- Bäckman, A. C., et al.
(författare)
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Antennal response of codling moth males, Cydia pomonella L. (Lepidoptera: Tortricidae), to the geometric isomers of codlemone and codlemone acetate
- 2000
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Ingår i: Journal of Comparative Physiology A. Sensory, neural, and behavioral physiology. - : Springer. - 0340-7594 .- 1432-1351. ; 186:6, s. 513-519
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Tidskriftsartikel (refereegranskat)abstract
- Single sensillum recordings from Cydia pomonella male antennae showed three different types of receptor neurons. The most abundant type was most sensitive to the main pheromone compound (E,E)-8,10-dodecadienol, while its response to the geometric isomers E,Z, Z,E and Z,Z was comparable to a tenfold lower dose of (E,E)-8,10-dodecadienol. This neuron type also responded to the four behaviorally antagonistic isomers of (Delta,Delta)-8,10-dodecadienyl acetate, among which it was most sensitive to the E,E isomer. Cross-adaptation studies showed that these compounds were all detected by the same receptor neuron type. Receptor neurons specifically tuned to (E,Z) or (Z,Z)-8,10-dodecadienol were not found, although these two compounds are behaviorally active. A second type of receptor neuron responded to all isomers of (Delta,Delta)-8,10-dodecadienyl acetate and was most sensitive to the E,E isomer. This neuron type did not respond to any of the isomers of (Delta,Delta)-8,10-dodecadienol. A third receptor neuron type was highly sensitive to the plant compound alpha-farnesene. The finding that the receptor neuron type tuned to the main pheromone compound responded even to strong behavioral antagonists aids the interpretation of ongoing behavioral studies for the development of the mating disruption technique in codling moth.
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| 320. |
- Bäckström, Torbjörn, et al.
(författare)
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Paradoxical effects of GABA-A modulators may explain sex steroid induced negative mood symptoms in some persons
- 2011
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Ingår i: Neuroscience. - Oxford : Elsevier BV. - 0306-4522 .- 1873-7544. ; 191:Special issue, s. 46-54
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Forskningsöversikt (refereegranskat)abstract
- Some women have negative mood symptoms, caused by progestagens in hormonal contraceptives or sequential hormone therapy or by progesterone in the luteal phase of the menstrual cycle, which may be attributed to metabolites acting on the GABA-A receptor. The GABA system is the major inhibitory system in the adult CNS and most positive modulators of the GABA-A receptor (benzodiazepines, barbiturates, alcohol, GABA steroids), induce inhibitory (e.g. anesthetic, sedative, anticonvulsant, anxiolytic) effects. However, some individuals have adverse effects (seizures, increased pain, anxiety, irritability, aggression) upon exposure. Positive GABA-A receptor modulators induce strong paradoxical effects including negative mood in 3%-8% of those exposed, while up to 25% have moderate symptoms. The effect is biphasic: low concentrations induce an adverse anxiogenic effect while higher concentrations decrease this effect and show inhibitory, calming properties. The prevalence of premenstrual dysphoric disorder (PMDD) is also 3%-8% among women in fertile ages, and up to 25% have more moderate symptoms of premenstrual syndrome (PMS). Patients with PMDD have severe luteal phase-related symptoms and show changes in GABA-A receptor sensitivity and GABA concentrations. Findings suggest that negative mood symptoms in women with PMDD are caused by the paradoxical effect of allopregnanolone mediated via the GABA-A receptor, which may be explained by one or more of three hypotheses regarding the paradoxical effect of GABA steroids on behavior: (1) under certain conditions, such as puberty, the relative fraction of certain GABA-A receptor subtypes may be altered, and at those subtypes the GABA steroids may act as negative modulators in contrast to their usual role as positive modulators; (2) in certain brain areas of vulnerable women the transmembrane C1(-) gradient may be altered by factors such as estrogens that favor excitability; (3) inhibition of inhibitory neurons may promote disinhibition, and hence excitability. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain. (C) 2011 Published by Elsevier Ltd on behalf of IBRO.
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