389 research outputs found
Pilot scale application of ozonated water wash - effect on microbiological and sensory quality parameters of processed iceberg lettuce during self-life
The aim of the study was to assess the effect of ozonated water wash on the microbiological and sensory quality parameters of minimally processed iceberg lettuce in pilot scale in comparison to aqueous chlorine wash. Alternative solutions for chlorine are needed, since its use is prohibited in organic food processing. Iceberg lettuce samples were washed with three different ozone solutions and the water wash and the 100 ppm chlorine wash were used as control. Ozone generator based on corona discharge was used to produce ozone at level 7 ppm. The samples (150 g) packed in oriented polypropylene pouches were stored for 10 days at +5C and the microbiological and sensory quality was analysed on days 1, 6 and 10. There was no significant difference between chlorine wash samples and the samples washed 1 min in a machine with ozonated water concerning the microbiological quality. Compared with the chlorine with lower concentrations of ozone it is possible to control the microbial load. Concerning the sensory quality all samples endured all of the treatments well except the treatment with 7 ppm ozone for 5 min. As a conclusion the bubbling gaseous ozone in water can be as effective disinfection method as chlorine wash when the following processing parameters are taken into account: concentration of ozone during the whole process, exposure time, water temperature and the amount and type of the organic material
Detection of aphid migrations in Finland
Our insect immigration warning system was built on the atmospheric dispersion model that has been used in predicting long-range transport of airborne pollen. We observed immigrations with a trap network consisting of rotating tow-nets, yellow sticky traps, and suction traps.
Based on our studies the aphids can be detected with radars when they occur in large numbers
Effects of replacement of barley with oats on milk fatty acid composition in dairy cows fed grass silage-based diets
Lääkeaineiden jäämät vesistöissä
Tiivistelmä. Lääkkeiden käytön lisääntyminen on johtanut uudenlaisen ympäristöongelman esille nousemiseen etenkin vesistöissä, jonne lääkeaineiden jäämiä kulkeutuu muun muassa maatalouden, teollisuuden ja sairaaloiden jätevesien mukana sekä riittämättömän jäteveden puhdistuksen seurauksena. Tutkimuksen tehtävänä on ollut selvittää mitä lääkeaineyhdisteitä vesistöihin päätyy, mitä haittaa näiden aineiden päätymisestä vesiekosysteemeihin aiheutuu ja minkälaisiin muihin ongelmiin tilanne voi johtaa.
Vesistöjen yleisimpiä lääkeryhmiä ovat tulehduskipulääkkeet, antibiootit, psykoaktiiviset lääkkeet, sydänlääkkeet sekä hormonit. Useiden lääkeaineiden on havaittu bioakkumuloituvan, biotransformoituvan ja rikastuvan ekosysteemeissä, sekä aiheuttavan oksidatiivista stressiä. Lääkeryhmillä on myös löydetty samankaltaisia vaikutuksia eri eliölajeilla tutkittuna, esimerkiksi hormonit ovat häirinneet eri lajeilla lisääntymistä ja hermostoon vaikuttavat psykoaktiiviset lääkkeet liikkumista. Lisäksi muun muassa simpukoilla oksidatiivistä stressiä aiheuttavat antibiootit ovat myös epidemioiden riskitekijä antibioottiresistenssin syntymisen takia vesistöissä, jotka altistuvat antibiooteille toistuvasti.
Haitallisia vaikutuksia ja merkittäviä muutoksia aineenvaihdunnan toimintaan on tutkittu ja löydetty niin vesistöjen selkärankaisissa että selkärangattomissa eliöissä. Suuri osa löydetyistä vaikutuksista on myös tarpeeksi merkittäviä muuttamaan populaatioiden ja ekosysteemien toimintaa, johtamalla mahdollisesti pienempiin populaatiokokoihin käyttäytymis- ja lisääntymismuutoksien seurauksena. Tämä voi puolestaan vaikuttaa ravinteiden saatavuuteen vesiekosysteemien ravintoverkoissa, mikä vaikuttaa myös ihmiseen.
Tutkimusten tulokset osoittavat, että lääkeaineiden jäämien pääsy vesistöihin on suuri riski paitsi näiden ekosysteemien eliöille myös ihmisille. Tästä syystä on tärkeää, että ongelmaan pyritään tulevassa tutkimuksessa kehittämään ratkaisuja mm. lääkejätteen käsittelyyn liittyvän lainsäädännön sekä jätevedenpuhdistamoiden tekniikan kehittämisen avulla. Osana tätä kehitystä on lääkeaineiden ja niiden metaboliittien käyttäytymisen selvittäminen vesiekosystemeeissä, mikä vaatii lisää tutkimusta
Profiling water vapor mixing ratios in Finland by means of a Raman lidar, a satellite and a model
We present tropospheric water vapor profiles measured with a Raman lidar during three field campaigns held in Finland. Co-located radio soundings are available throughout the period for the calibration of the lidar signals. We investigate the possibility of calibrating the lidar water vapor profiles in the absence of co-existing on-site soundings using water vapor profiles from the combined Advanced InfraRed Sounder (AIRS) and the Advanced Microwave Sounding Unit (AMSU) satellite product; the Aire Limitee Adaptation dynamique Developpement INternational and High Resolution Limited Area Model (ALADIN/HIRLAM) numerical weather prediction (NWP) system, and the nearest radio sounding station located 100 km away from the lidar site (only for the permanent location of the lidar). The uncertainties of the calibration factor derived from the soundings, the satellite and the model data are <2.8, 7.4 and 3.9 %, respectively. We also include water vapor mixing ratio intercomparisons between the radio soundings and the various instruments/model for the period of the campaigns. A good agreement is observed for all comparisons with relative errors that do not exceed 50% up to 8 km altitude in most cases. A 4-year seasonal analysis of vertical water vapor is also presented for the Kuopio site in Finland. During winter months, the air in Kuopio is dry (1.15 +/- 0.40 g kg(-1)); during summer it is wet (5.54 +/- 1.02 g kg(-1)); and at other times, the air is in an intermediate state. These are averaged values over the lowest 2 km in the atmosphere. Above that height a quick decrease in water vapor mixing ratios is observed, except during summer months where favorable atmospheric conditions enable higher mixing ratio values at higher altitudes. Lastly, the seasonal change in disagreement between the lidar and the model has been studied. The analysis showed that, on average, the model underestimates water vapor mixing ratios at high altitudes during spring and summer.Peer reviewe
Between-cow variation in milk fatty acids associated with methane production
We evaluated the between-cow (b-cow) variation and repeatability in omasal and milk fatty acids (FA) related to methane (CH4) emission. The dataset was originated from 9 studies with rumen-cannulated dairy cows conducted using either a switch-back or a Latin square design. Production of CH(4)per mole of VFA (Y_CH(4)VFA) was calculated based on VFA stoichiometry. Experiment, diet within experiment, period within experiment, and cow within experiment were considered as random factors. Empirical models were developed between the variables of interest by univariate and bivariate mixed model regression analysis. The variation associated with diet was higher than the b-cow variation with low repeatability (< 0.25) for milk odd- and branch-chain FA (OBCFA). Similarly, for de novo synthesized milk FA, diet variation was similar to 3-fold greater than the b-cow variation; repeatability for these FA was moderate to high (0.34-0.58). Also, for bothcis-9 C18:1 andcis-9cis-12cis-15 C18:3 diet variation was more than double the b-cow variation, but repeatability was moderate. Among the de novo milk FA, C4:0 was positively related with stoichiometric Y_CH(4)VFA, while for OBCFA,anteisoC15:0 and C15:0 were negatively related with it. Notably, when analyzing the relationship between omasal FA and milk FA we observed positive intercept estimates for all the OBCFA, which may indicate endogenous post-ruminal synthesis of these FA, most likely in the mammary gland. For milkisoC13:0,isoC15:0,anteisoC15:0, and C15:0 were positively influenced by omasal proportion of their respective FA and by energy balance. In contrast, the concentration of milk C17:0,isoC18:0, C18:0,cis-11 C18:1, andcis-9cis-12cis-15 C18:3 were positively influenced by omasal proportion of their respective FA but negatively related to calculated energy balance. Our findings demonstrate that for most milk FA examined, a larger variation is attributed to diet than b-cow differences with low to moderate repeatability. While some milk FA were positively or negatively related with Y_CH(4)VFA, there was a pronounced effect of calculated energy balance on these estimates. Additionally, even though OBCFA have been indicated as markers of rumen function, our results suggest that endogenous synthesis of these FA may occur, which therefore, may limit the utilization of milk FA as a proxy for CH(4)predictions for cows fed the same diet
Hopping modulation in a one-dimensional Fermi-Hubbard Hamiltonian
We consider a strongly repulsive two-component Fermi gas in a one-dimensional
(1D) optical lattice described in terms of a Hubbard Hamiltonian. We analyze
the response of the system to a periodic modulation of the hopping amplitude in
presence of large two body interaction. By (essentially) exact simulations of
the time evolution, we find a non-trivial double occupancy frequency
dependence. We show how the dependence relates to the spectral features of the
system given by the Bethe ansatz. The discrete nature of the spectrum is
clearly reflected in the double occupancy after long enough modulation time. We
also discuss the implications of the 1D results to experiments in higher
dimensional systems.Comment: 4 pages, 5 figures; minor changes in the text, updated references
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