5,776 research outputs found
High-temperature drying of organically grown bread rye
Mycotoxin producing fungi are naturally occurring components in cereals. When produced, some of the mycotoxins are toxic to humans and animals. Heat treatment is a method to reduce fungal abundance on cereals. The objectives of this work have been to provide more knowledge on this topic, and specifically to optimise the drum drying technique with reference to reducing the dissemination and proliferation of fungi on organically grown rye without reducing the baking quality of the grain.
The results show that drum drying can be a very efficient method in reducing fungi colonising on grain. For rye it is possible to achieve high effects on fungi without reducing the baking abilities. When drying at a constant maximum grain temperature of 64°C, the treatment resulted in less than 1% of the yeast propagules and less than 2% of the filamentous fungi, compared to what was found in the reference grain.
As drying temperatures and time for the grain to be treated are essential, the drum drier must be equipped with an effective control unit. The experiments show that a control system using fixed constant maximum grain temperature is most suitable
COMPARISON OF GROWTH PERFORMANCE OF BEEF CALVES FROM DIFFERENT GENETIC STRAINS REARED UNDER ORGANIC CONDITIONs (D. 3.2)
The objective of the present study was to compare growth performance of 15 Danish Holstein bull (DHB) calves, 15 Limousine x Danish Holstein crossbred bull (CB) calves and 15 Limousine x Danish Holstein crossbred heifer (CH) calves reared under organic conditions. Spring-born calves were puchased at private farms and arrived at approximately 20 days of age with an average initial body weight of 52.9, 58.5 and 56.1 kg, (SEM 2.6) for DHB, CB and CH, respectively. Calves were kept indoor until weaning at 3 months of age. Calves were gradually introduced to a grass-silage based ration from 3 to 4 months of age. From 4 to 7 months calves were kept on mix grass pasture of ryegrass and white clover. There were significant differences between treatment groups in terms of average daily gain (ADGP1) during the first summer pasture period, average daily gain (ADGI) during the indoor winter period, and average daily gain (ADGP2) during the second summer pasture period (first 7 weeks). Thus, CB had significantly greater ADG than CH for all three periods with DHB being in between. CB had greater values than DHB and CH in terms of LWP1 144, 140 and 135 (SEM 4) kg, ADGP1 1.15, 1.04 and 0.95 (SEM 0.05) kg/d, LW Indoor 222, 213, and 201 (SEM 5) kg and ADGI 1.06, 1.02 and 0.95 (SEM 0.02) kg/d, LWP2 462, 445 and 414 (SEM 9) kg and ADGP2 1.24, 0.98 and 0.68 (SEM 0.04) kg/d for CB, DHB and CH, respectively. The final live weight were not different between CB and DHB but was significantly lower for CH than DHB and CB (483, 539 and 582 (SEM 8) kg, for CH, DHB and CB, respectively). Overall growth performance across all periods was 13% higher for CB than CH
Bleaching and diffusion dynamics in optofluidic dye lasers
We have investigated the bleaching dynamics that occur in optofluidic dye
lasers where the liquid laser dye in a microfluidic channel is locally bleached
due to optical pumping. We find that for microfluidic devices, the dye
bleaching may be compensated through diffusion of dye molecules alone. By
relying on diffusion rather than convection to generate the necessary dye
replenishment, our observation potentially allows for a significant
simplification of optofluidic dye laser device layouts, omitting the need for
cumbersome and costly external fluidic handling or on-chip microfluidic pumping
devices.Comment: 3 pages including 3 figures. Accepted for AP
A New Phytochemical Screening Programme used for Crops grown with Organic and Conventional Methods
A broad screening programme, covering the most general phytochemical groups of compounds, was developed on the basis of Thin Layer Chromatography (TLC). A total of 46 TLC systems, comprising 26 derivatization reagents, 3 stationary phases, and 4 mobile phases, were included. The TLC systems were classified according to the groups of phytochemical compounds detected: Alcohols and phenolic compounds; Carbohydrates; N-containing compounds; Organic acids and lipids; P-containing compounds; S-containing compounds, and Terpenoids. Furthermore, one group of TLC systems detected compounds from several of the mentioned groups.
The screening programme was applied in the screening of potatoes (S. tuberosum L.), peas (P. sativum L.), kale (B. oleracea L.), carrots (D. carota L.), and apples (M. domestica Borkh.), cultivated with combinations of organic and conventional methods for plant protection and nutrient supply, for phytochemical differences (biomarkers).
Distinctive phytochemical differences were found between the differently cultivated samples of these crops. In peas and carrots only one biomarker was found. In peas the biomarker was related to the soil conditions, while the biomarker in carrots was related to the use of pesticides. In potato, two biomarkers related to the use of pesticides were found. Three biomarkers were found in kale. Two of these could be related to the use of pesticide, while the last was related to either fertiliser or soil conditions. Several biomarkers were found apples, but a relation to the cultivation methods was not clear. Three of the biomarkers in apples could be related to either the use of pesticides or fertiliser, while no conclusions could be drawn from the other biomarkers found.
The results of the screening programme form the basis for a potential development of a kit to detect whether crops are organically- or conventionally cultivated. Furthermore, the results from this part and other parts of the project "Organic food and health â a multigenerational animal experiment" provide basis for the selection of which secondary compounds to quantify by specific chemical analysis, isolate, and/or structure elucidation
Hot water in the inner 100 AU of the Class 0 protostar NGC1333 IRAS2A
Evaporation of water ice above 100 K in the inner few 100 AU of low-mass
embedded protostars (the so-called hot core) should produce quiescent water
vapor abundances of ~10^-4 relative to H2. Observational evidence so far points
at abundances of only a few 10^-6. However, these values are based on spherical
models, which are known from interferometric studies to be inaccurate on the
relevant spatial scales. Are hot cores really that much drier than expected, or
are the low abundances an artifact of the inaccurate physical models? We
present deep velocity-resolved Herschel-HIFI spectra of the 3(12)-3(03) lines
of H2-16O and H2-18O (1097 GHz, Eup/k = 249 K) in the low-mass Class 0
protostar NGC1333 IRAS2A. A spherical radiative transfer model with a power-law
density profile is unable to reproduce both the HIFI data and existing
interferometric data on the H2-18O 3(13)-2(20) line (203 GHz, Eup/k = 204 K).
Instead, the HIFI spectra likely show optically thick emission from a hot core
with a radius of about 100 AU. The mass of the hot core is estimated from the
C18O J=9-8 and 10-9 lines. We derive a lower limit to the hot water abundance
of 2x10^-5, consistent with the theoretical predictions of ~10^-4. The revised
HDO/H2O abundance ratio is 1x10^-3, an order of magnitude lower than previously
estimated.Comment: Accepted by ApJ; 12 pages in emulateapj format; 7 figure
Imaging Oxygen Distribution in Marine Sediments. The Importance of Bioturbation and Sediment Heterogeneity
The influence of sediment oxygen heterogeneity, due to bioturbation, on diffusive oxygen flux was investigated. Laboratory experiments were carried out with 3 macrobenthic species presenting different bioturbation behaviour patterns:the polychaetes Nereis diversicolor and Nereis virens, both constructing ventilated galleries in the sediment column, and the gastropod Cyclope neritea, a burrowing species which does not build any structure. Oxygen two-dimensional distribution in sediments was quantified by means of the optical planar optode technique. Diffusive oxygen fluxes (mean and integrated) and a variability index were calculated on the captured oxygen images. All species increased sediment oxygen heterogeneity compared to the controls without animals. This was particularly noticeable with the polychaetes because of the construction of more or less complex burrows. Integrated diffusive oxygen flux increased with oxygen heterogeneity due to the production of interface available for solute exchanges between overlying water and sediments. This work shows that sediment heterogeneity is an important feature of the control of oxygen exchanges at the sedimentâwater interface
Conductance of a quantum point contact based on spin-density-functional theory
We present full quantum mechanical conductance calculations of a quantum
point contact (QPC) performed in the framework of the density functional theory
(DFT) in the local spin-density approximation (LDA). We show that a
spin-degeneracy of the conductance channels is lifted and the total conductance
exhibits a broad plateau-like feature at 0.5*2e^{2}/h. The lifting of the
spin-degeneracy is a generic feature of all studied QPC structures (both very
short and very long ones; with the lengths in the range 40<l<500 nm). The
calculated conductance also shows a hysteresis for forward- and backward sweeps
of the gate voltage. These features in the conductance can be traced to the
formation of weakly coupled quasi-bound states (magnetic impurities) inside the
QPC (also predicted in previous DFT-based studies). A comparison of obtained
results with the experimental data shows however, that while the spin-DFT based
"first-principle" calculations exhibits the spin polarization in the QPC, the
calculated conductance clearly does not reproduce the 0.7 anomaly observed in
almost all QPCs of various geometries. We critically examine major features of
the standard DFT-based approach to the conductance calculations and argue that
its inability to reproduce the 0.7 anomaly might be related to the infamous
derivative discontinuity problem of the DFT leading to spurious
self-interaction errors not corrected in the standard LDA. Our results indicate
that the formation of the magnetic impurities in the QPC might be an artefact
of the LDA when localization of charge is expected to occur. We thus argue that
an accurate description of the QPC structure would require approaches that go
beyond the standard DFT+LDA schemes.Comment: 9 pages, 5 figure
Navigating cognitive innovation
This paper revisits the concept of Cognitive Innovation with the aim of helping newcomers appreciate its (intended) demarcating purpose and relevance to the wider literature on cognition and creativity in the humanities, arts, and sciences. Particular emphasis is paid to discussion of the pitfalls of sense-making and the concept's affordance. The main argument presented is that proponents of the concept face the dilemma of seeking to demonstrate its transdisciplinary nature and applicability vis-a-vis retaining its semantic distinctness. Proceeding from a classification of Cognitive Innovation as a dispositional construct, we discuss how it feeds into existing research approaches and opens up new sensibilities in related areas. The perspectives of temporality, interdisciplinary balancing, technology, and metatheories are proposed as promising areas for future elaboration of the function of Cognitive Innovation
Preparation of ultracold atom clouds at the shot noise level
We prepare number stabilized ultracold clouds through the real-time analysis
of non-destructive images and the application of feedback. In our experiments,
the atom number is determined by high precision Faraday imaging
with uncertainty below the shot noise level, i.e., . Based on this measurement, feedback is applied to reduce the atom
number to a user-defined target, whereupon a second imaging series probes the
number stabilized cloud. By this method, we show that the atom number in
ultracold clouds can be prepared below the shot noise level.Comment: Main text: 4 Figures, 4 pages. Supplemental Information: 4 figures, 5
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