485 research outputs found
Dietary supplements utilization: an explanatory survey among Swiss consumers
Dietary supplement (DS) use increased rapidly over the last years. However evidence of benefits of many DS for healthy users are scarce and may not equate known risks of overdose, drug interaction and recently discovered negative long-term effects. Therefore this study aimed to investigate perceptions and motivations of DS users in Lausanne, Switzerland. Method A convenience sample was recruited at the entrance of local sales points. Data were collected in on-site semi-structured interviews to assess dietary supplementation habits. Results The 119 participants provided information on 147 users. Among 273 declared products, the majority were mixed products, containing minerals and vitamins (78), mineral products (69), and herbal products (28). 55% of DS users took more than one product simultaneously. Seventy five percent of participants indicated that DS use presents no risk or nearly no risk and about half (49%) of participants did not inform their physician about their consumption. Male participants reported to share this information with their physicians significantly less frequently than female participants (p = 0.008). About half of participants looked for information on potential risks of DS, men significantly more often than women (p=0.001). Discussion According to other studies in the US, our study shows that, in Lausanne (Switzerland), DS are commonly used as mixed products. Risk perception seems generally low among DS users. Implications Physicians should be trained to evaluate patientsʼ health behaviour and needs in order to provide good evidence based information or propose alternatives to DS use
Interactions of local climatic, biotic and hydrogeochemical processes facilitate phosphorus dynamics along an Everglades forest-marsh gradient
Ecosystem nutrient cycling is often complex because nutrient dynamics within and between systems are mediated by the interaction of biological and geochemical conditions operating at different temporal and spatial scales. Vegetated patches in semiarid and wetland landscapes have been shown to exemplify some of these patterns and processes. We investigated biological and geochemical factors suggested to contribute to phosphorus (P) movement and availability along a forest-marsh gradient in an Everglades tree island. Our study illustrated processes that are consistent with the chemohydrodynamic nutrient (CHNT) hypothesis and the trigger-transfer, pulse-reserve (TTPR) model developed for semiarid systems. Comparison with the TTPR model was constructive as it elaborated several significant patterns and processes of the tree island ecosystem including: (1) concentration of the limiting resource (P) in the source patch (High Head which constitutes the reserve) compared with the resource-poor landscape, (2) soil zone calcite precipitation requiring strong seasonality for evapotranspiration to promote conditions for secondary soil development and calcium phosphate reprecipitation, (3) rewetting of previously dry soils by early wet season precipitation events, and (4) antecedent conditions of the source patch, including landscape position that modulated the effect of the precipitation trigger. Thus, our study showed how water availability drives soil water P dynamics and, potentially, stability of mineral soil P in this tree island ecosystem. In landscapes with extensive water management, these processes can be asynchronous with the seasonality of hydrologic dynamics, tipping the balance between a sink and source of a limiting nutrient
On the Discovery of Monocular Rivalry by Tscherning in 1898:Translation and Review
Monocular rivalry was named by Breese in 1899. He made prolonged observation of superimposed orthogonal gratings; they fluctuated in clarity with either one or the other grating occasionally being visible alone. A year earlier, Tscherning observed similar fluctuations with a grid of vertical and horizontal lines and with other stimuli; we draw attention to his prior account. Monocular rivalry has since been shown to occur with a wide variety of superimposed patterns with several independent rediscoveries of it. We also argue that Helmholtz described some phenomenon other than monocular rivalry in 1867
Enhanced glucose uptake via GLUT4 fuels recovery from calcium overload after ischaemia-reperfusion injury in sevoflurane- but not propofol-treated hearts
Background So far, no study has explored the effects of sevoflurane, propofol, and Intralipid on metabolic flux rates of fatty acid oxidation (FOX) and glucose oxidation (GOX) in hearts exposed to ischaemia-reperfusion. Methods Isolated paced working rat hearts were exposed to 20 min of ischaemia and 30 min of reperfusion. Peri-ischaemic sevoflurane (2 vol%) and propofol (100 µM) in the formulation of 1% Diprivan® were assessed for their effects on oxidative energy metabolism and intracellular diastolic and systolic Ca2+ concentrations. Substrate flux was measured using [3H]palmitate and [14C]glucose and [Ca2+] using indo-1AM. Western blotting was used to determine the expression of the sarcolemmal glucose transporter GLUT4 in lipid rafts. Biochemical analyses of nucleotides, ceramides, and 32 acylcarnitines were also performed. Results Sevoflurane, but not propofol, improved the recovery of left ventricular work (P=0.008) and myocardial efficiency (P=0.008) compared with untreated ischaemic hearts. This functional improvement was accompanied by reduced increases in post-ischaemic diastolic and systolic intracellular Ca2+ concentrations (P=0.008). Sevoflurane, but not propofol, increased GOX (P=0.009) and decreased FOX (P=0.019) in hearts exposed to ischaemia-reperfusion. GLUT4 expression was markedly increased in lipid rafts of sevoflurane-treated hearts (P=0.016). Increased GOX closely correlated with reduced Ca2+ overload. Intralipid alone decreased energy charge and increased long-chain and hydroxyacylcarnitine tissue levels, whereas sevoflurane decreased toxic ceramide formation. Conclusions Enhanced glucose uptake via GLUT4 fuels recovery from Ca2+ overload after ischaemia-reperfusion in sevoflurane- but not propofol-treated hearts. The use of a high propofol concentration (100 µM) did not result in similar protectio
Uncertainty in United States coastal wetland greenhouse gas inventorying
© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Research Letters 13 (2018): 115005, doi:10.1088/1748-9326/aae157.Coastal wetlands store carbon dioxide (CO2) and emit CO2 and methane (CH4) making them an important part of greenhouse gas (GHG) inventorying. In the contiguous United States (CONUS), a coastal wetland inventory was recently calculated by combining maps of wetland type and change with soil, biomass, and CH4 flux data from a literature review. We assess uncertainty in this developing carbon monitoring system to quantify confidence in the inventory process itself and to prioritize future research. We provide a value-added analysis by defining types and scales of uncertainty for assumptions, burial and emissions datasets, and wetland maps, simulating 10 000 iterations of a simplified version of the inventory, and performing a sensitivity analysis. Coastal wetlands were likely a source of net-CO2-equivalent (CO2e) emissions from 2006–2011. Although stable estuarine wetlands were likely a CO2e sink, this effect was counteracted by catastrophic soil losses in the Gulf Coast, and CH4 emissions from tidal freshwater wetlands. The direction and magnitude of total CONUS CO2e flux were most sensitive to uncertainty in emissions and burial data, and assumptions about how to calculate the inventory. Critical data uncertainties included CH4 emissions for stable freshwater wetlands and carbon burial rates for all coastal wetlands. Critical assumptions included the average depth of soil affected by erosion events, the method used to convert CH4 fluxes to CO2e, and the fraction of carbon lost to the atmosphere following an erosion event. The inventory was relatively insensitive to mapping uncertainties. Future versions could be improved by collecting additional data, especially the depth affected by loss events, and by better mapping salinity and inundation gradients relevant to key GHG fluxes. Social Media Abstract: US coastal wetlands were a recent and uncertain source of greenhouse gasses because of CH4 and erosion.Financial
support was provided primarily by NASA Carbon
Monitoring Systems (NNH14AY67I) and the USGS
Land Carbon Program, with additional support from
The Smithsonian Institution, The Coastal Carbon
Research Coordination Network (DEB-1655622), and
NOAA Grant: NA16NMF4630103
Type-specific radioimmunoassays for the gp70s of mink cell focus-inducing murine leukemia viruses: expression of a cross-reacting antigen in cells infected with the friend strain of the spleen focus-forming virus
We have isolated the gp70 of a helper-independent strain of a Friend mink cell focus-inducing (MCF) virus, Fr-MCF-1. This recombinant virus, like the previously described AKR-MCF viruses, has been shown by both biological and biochemical means to be an envelope gene recombinant between Friend murine leukemia virus (F-MuLV) and a mouse xenotropic virus. Utilizing (125)I- labeled Fr-MCF-1 gp70 and antiserum prepared against an MCF strain of Moloney type-C virus (Mol-MCF(83)), we have developed a radioimmunoassay which detects immunological determinant (s)contained in the gp70s of MCF viruses derived from F-MuLV, Mol-MuLV, and AKR-MuLV. This MCF determinant(s) is not detected in the ecotropic parents of each of these MCF viruses, nor in helper-independent murine xenotropic viruses derived from Swiss or BALB/c mice. A protein partially cross-reactive with the MCF gp70 determinant(s) is detected in a replicating xenotropic virus derived from NZB mice. Utilizing this MCF gp70 specific immunoassay, we can detect a cross-reacting gene product coded for by the Friend strain of the spleen focus-forming virus (SFFV) in rat fibroblasts nonproductively infected with SFFV. The results support earlier molecular hybridization studies which indicated that the genome of SFFV contains genetic information derived from both F-MuLV and xenotropic virus, and that the xenotropic-related sequences in SFFV are highly related to those found in MCF murine type-C viruses
Sigmund Exner's (1887) einige beobachtungen über bewegungsnachbilder (some observations on movement aftereffects):an illustrated translation with commentary
In his original contribution, Exner’s principal concern was a comparison between the properties of different aftereffects, and particularly to determine whether aftereffects of motion were similar to those of color and whether they could be encompassed within a unified physiological framework. Despite the fact that he was unable to answer his main question, there are some excellent—so far unknown—contributions in Exner’s paper. For example, he describes observations that can be related to binocular interaction, not only in motion aftereffects but also in rivalry. To the best of our knowledge, Exner provides the first description of binocular rivalry induced by differently moving patterns in each eye, for motion as well as for their aftereffects. Moreover, apart from several known, but beautifully addressed, phenomena he makes a clear distinction between motion in depth based on stimulus properties and motion in depth based on the interpretation of motion. That is, the experience of movement, as distinct from the perception of movement. The experience, unlike the perception, did not result in a motion aftereffect in depth
Greater temperature sensitivity of plant phenology at colder sites: implications for convergence across northern latitudes
Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance at colder sites. To test this hypothesis, we examined up to 20 years of phenology data for 47 tundra plant species at 18 high-latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than warmer high-latitude locations. A similar pattern was seen over time for the flowering phenology of a widespread species, Cassiope tetragona. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence in flowering times and therefore an increase in gene flow across latitudes as the climate warms
Modulation of 11β-hydroxysteroid dehydrogenase as a strategy to reduce vascular inflammation
Atherosclerosis is a chronic inflammatory disease in which initial vascular damage leads to extensive macrophage and lymphocyte infiltration. Although acutely glucocorticoids suppress inflammation, chronic glucocorticoid excess worsens atherosclerosis, possibly by exacerbating systemic cardiovascular risk factors. However, glucocorticoid action within the lesion may reduce neointimal proliferation and inflammation. Glucocorticoid levels within cells do not necessarily reflect circulating levels due to pre-receptor metabolism by 11β-hydroxysteroid dehydrogenases (11β-HSDs). 11β-HSD2 converts active glucocorticoids into inert 11-keto forms. 11β-HSD1 catalyses the reverse reaction, regenerating active glucocorticoids. 11β-HSD2-deficiency/ inhibition causes hypertension, whereas deficiency/ inhibition of 11β-HSD1 generates a cardioprotective lipid profile and improves glycemic control. Importantly, 11β-HSD1-deficiency/ inhibition is atheroprotective, whereas 11β-HSD2-deficiency accelerates atherosclerosis. These effects are largely independent of systemic risk factors, reflecting modulation of glucocorticoid action and inflammation within the vasculature. Here, we consider whether evidence linking the 11β-HSDs to vascular inflammation suggests these isozymes are potential therapeutic targets in vascular injury and atherosclerosis
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