836 research outputs found
Deriving inherent optical properties from decomposition of hyperspectral non-water absorption
Semi-analytical algorithms (SAAs) developed for multispectral ocean color sensors have benefited from a variety of approaches for retrieving the magnitude and spectral shape of inherent optical properties (IOPs). SAAs generally follow two approaches: 1) simultaneous retrieval of all IOPs, resulting in pre-defined bio-optical models and spectral dependence between IOPs and 2) retrieval of bulk IOPs (absorption and backscattering) first followed by decomposition into separate components, allowing for independent retrievals of some components. Current algorithms used to decompose hyperspectral remotely-sensed reflectance into IOPs follow the first strategy. Here, a spectral deconvolution algorithm for incorporation into the second strategy is presented that decomposes at-w(λ) from in situ measurements and estimates absorption due to phytoplankton (aph(λ)) and colored detrital material (adg(λ)) free of explicit assumptions. The algorithm described here, Derivative Analysis and Iterative Spectral Evaluation of Absorption (DAISEA), provides estimates of aph(λ) and adg(λ) over a spectral range from 350 to 700 nm. Estimated aph(λ) and adg(λ) showed an average normalized root mean square difference of \u3c30% and \u3c20%, respectively, from 350 to 650 nm for the majority of optically distinct environments considered. Estimated Sdg median difference was \u3c20% for all environments considered, while distribution of Sdg uncertainty suggests that biogeochemical variability represented by Sdg can be estimated free of bias. DAISEA results suggest that hyperspectral satellite ocean color data will improve our ability to track biogeochemical processes affiliated with variability in adg(λ) and Sdg free of explicit assumptions
Consumer perception of food products involving genetic modification: Results from a qualitative study in four Nordic countries
1. The present study addresses consumer acceptance of food products involving the use of different applications of genetic modification in four Nordic countries. Three food products were used as examples: hard cheese, hard candy, and salmon. Three types of applications of genetic modification were investigated: modification of the raw material, use of genetic modification in enzyme production, and direct use of genetically modified microorganisms. In addition, three levels of presence of the genetically modified material in the final product were investigated: not present, present, and present and living/able to function. 2. The results from consumer samples in Denmark, Finland, Norway and Sweden are remarkably similar, showing a strong stability in consumer reactions to the use of genetic modification in food production in these four countries. 3. Consumer perception is characterised by a basic dichotomy of GM and non-GM products. Being non-GM is regarded as a major benefit in itself. When a product involves genetic modification, this elicits numerous negative assocations, of which the strongest ones are ‘unhealthy’ and ‘uncertainty.’ 4. The level of presence of the genetically modified material in the final product has a clear impact on consumer acceptance. When the GM material is present and viable/able to function, acceptance is lowest. 5. The type of application of genetic modification has an impact on consumer acceptance as well, but it differs across products. Still, there is a clear tendency that acceptance of salmon products where the salmon itself was genetically modified was lowest among all products tested. 6. The consumer benefits which the application of GM brings about (e.g., improved taste, functional benefits, environmental benefits) are largely perceived, but cannot overcompensate for the negative associations to GM. In some cases, a supposed benefit (e.g., faster growth of salmon, leading to reduced energy costs) was actually perceived as a disadvantage. Benefits combining personal tangible benefits with societal relevance (e.g., a low calorie candy which can be consumed by people suffering from diabetes) may have most positive impact on consumer acceptance.Consumer behaviour; Buying behaviour; Food; Denmark; Norway; Sweden; Finland
Expanding understanding of optical variability in Lake Superior with a 4-year dataset
Lake Superior is one of the largest freshwater lakes on our planet, but few optical observations have been made to allow for the development and validation of visible spectral satellite remote sensing products. The dataset described here focuses on coincidently observing inherent and apparent optical properties along with biogeochemical parameters. Specifically, we observe remote sensing reflectance, absorption, scattering, backscattering, attenuation, chlorophyll concentration, and suspended particulate matter over the ice-free months of 2013-2016. The dataset substantially increases the optical knowledge of the lake. In addition to visible spectral satellite algorithm development, the dataset is valuable for characterizing the variable light field, particle, phytoplankton, and colored dissolved organic matter distributions, and helpful in food web and carbon cycle investigations. The compiled data can be freely accessed at https://seabass.gsfc.nasa.gov/archive/URI/Mouw/LakeSuperior/
Two-Photon Doppler cooling of alkaline-earth-metal and ytterbium atoms
A new possibility of laser cooling of alkaline-earth-metal and Ytterbium
atoms using a two-photon transition is analyzed. We consider a -
transition, with excitation in near resonance with the
level. This greatly increases the two-photon transition rate, allowing an
effective transfer of momentum. The experimental implementation of this
technique is discussed and we show that for Calcium, for example, two-photon
cooling can be used to achieve a Doppler limit of 123 microKelvin. The
efficiency of this cooling scheme and the main loss mechanisms are analyzed.Comment: 7 pages, 5 figure
Expanding understanding of optical variability in Lake Superior with a 4-year dataset
Lake Superior is one of the largest freshwater lakes on our planet,
but few optical observations have been made to allow for the development and
validation of visible spectral satellite remote sensing products. The dataset
described here focuses on coincidently observing inherent and apparent
optical properties along with biogeochemical parameters. Specifically, we
observe remote sensing reflectance, absorption, scattering, backscattering,
attenuation, chlorophyll concentration, and suspended particulate matter over
the ice-free months of 2013–2016. The dataset substantially increases the
optical knowledge of the lake. In addition to visible spectral satellite
algorithm development, the dataset is valuable for characterizing the
variable light field, particle, phytoplankton, and colored dissolved organic
matter distributions, and helpful in food web and carbon cycle
investigations. The compiled data can be freely accessed at
https://seabass.gsfc.nasa.gov/archive/URI/Mouw/LakeSuperior/
The Relation between Attitudes toward Functional Foods and Satisfaction with Food-Related Life
Purpose – To assess the effect of attitudes towards functional foods (FF) on university students’ satisfaction with food-related life and to distinguish student typologies, considering that the attitudes towards FF are not homogeneous among consumers. Design/methodology - A survey was applied to 372 university students (mean age=20.4 years, SD=2.4) in southern Chile. The questionnaire included the Attitudes towards Functional Foods (AFF) questionnaire and the Satisfaction with Food-related Life (SWFL) scale, questions about consumption and knowledge about FF and socio-demographic characteristics. Findings – Using Confirmatory Factor Analysis (CFA) and Structural Equation Modelling, it was found that attitudes toward functional foods directly and significantly influence students’ satisfaction with food-related life. A cluster analysis applied to the Z-scores from the factors obtained by the CFA classified three typologies: Positive towards FF (36.3%), moderately positive towards FF (43.0%) and negative towards FF (20.7%). The positive towards FF type had a significantly greater SWFL score than the negative towards FF type. The types differ according to consumption and knowledge about FF. Research limitations/implications – This study was conducted in the context of only one country in South America. Originality/value – This study is the first that assesses the effect of AFF on satisfaction with food-related life in a sample of university students. Fostering positive attitudes towards FF will allow for a growth in the degree of satisfaction with food-related life of university students with features similar to those of the study sample
Changing micronutrient intake through (voluntary) behaviour change. The case of folate.
The objective of this study was to relate behaviour change mechanisms to nutritionally relevant behaviour and demonstrate how the different mechanisms can affect attempts to change these behaviours. Folate was used as an example to illuminate the possibilities and challenges in inducing behaviour change. The behaviours affecting folate intake were recognised and categorised. Behaviour change mechanisms from "rational model of man", behavioural economics, health psychology and social psychology were identified and aligned against folate-related behaviours. The folate example demonstrated the complexity of mechanisms influencing possible behavioural changes, even though this only targets the intake of a single micronutrient. When considering possible options to promote folate intake, the feasibility of producing the desired outcome should be related to the mechanisms of required changes in behaviour and the possible alternatives that require no or only minor changes in behaviour. Dissecting the theories provides new approaches to food-related behaviour that will aid the development of batteries of policy options when targeting nutritional problems
The frequency of anti-infliximab antibodies in patients with rheumatoid arthritis treated in routine care and the associations with adverse drug reactions and treatment failure
Objectives. To investigate the frequency of anti-infliximab antibodies in patients with RA and the associations with adverse drug reactions and treatment failure. Methods. Based on the DANBIO registry, patients with RA who initiated treatment with infliximab at Hvidovre Hospital between 2000 and 2008 and had available serum samples were identified. The patients were followed for 52 weeks. Anti-infliximab antibodies were determined prior to infusion at baseline and during follow-up (weeks 2, 6, 14 and 52 or at withdrawal) using the IMPACT indirect assay (Roche Diagnostics) and merged with clinical data prospectively registered in the DANBIO registry. Results. A total of 218 patients with RA were included (80% females, median age 56 years, disease duration 10 years, 65% RF positive, median DAS28 = 5.0). During the 52-week follow-up, 28 patients (13%) withdrew due to adverse events and 50 (23%) due to treatment failure. Antibodies were detected in 118 patients (54%) during follow-up. Patients with detectable anti-infliximab antibodies after 6 weeks had an increased risk of adverse drug reactions [hazard ratio (HR) = 5.06, 95% CI 2.36, 10.84; P < 0.0001] compared with patients without anti-infliximab antibodies. Similar results were observed in patients with anti-infliximab antibodies after 14 weeks (HR = 3.30, 95% CI 1.56, 6.99; P = 0.0009). Patients with detectable anti-infliximab antibodies during the 52-week follow-up were less likely to achieve sustained minimal disease activity and remission. Conclusion. Early anti-infliximab antibody formation increased the risk of adverse drug reactions, including infusion reactions. Anti-infliximab antibody formation during the 52-week follow-up decreased the likelihood of minimal disease activity and remission in patients with RA treated in routine car
Magnetic trapping of metastable atomic strontium
We report the magnetic trapping of metastable atomic strontium. Atoms
are cooled in a magneto-optical trap (MOT) operating on the dipole allowed
transition at 461 nm. Decay via
continuously loads a magnetic trap formed by the quadrupole magnetic field of
the MOT. Over atoms at a density of cm and
temperature of 1 mK are trapped. The atom temperature is significantly lower
than what would be expected from the kinetic and potential energy of atoms as
they are transferred from the MOT. This suggests that thermalization and
evaporative cooling are occurring in the magnetic trap.Comment: This paper has been accepted by PR
Long-Time Asymptotics of Perturbed Finite-Gap Korteweg-de Vries Solutions
We apply the method of nonlinear steepest descent to compute the long-time
asymptotics of solutions of the Korteweg--de Vries equation which are decaying
perturbations of a quasi-periodic finite-gap background solution. We compute a
nonlinear dispersion relation and show that the plane splits into
soliton regions which are interlaced by oscillatory regions, where
is the number of spectral gaps.
In the soliton regions the solution is asymptotically given by a number of
solitons travelling on top of finite-gap solutions which are in the same
isospectral class as the background solution. In the oscillatory region the
solution can be described by a modulated finite-gap solution plus a decaying
dispersive tail. The modulation is given by phase transition on the isospectral
torus and is, together with the dispersive tail, explicitly characterized in
terms of Abelian integrals on the underlying hyperelliptic curve.Comment: 45 pages. arXiv admin note: substantial text overlap with
arXiv:0705.034
- …