Tjernobyl och rennäringen - Lägesrapport från Sverige

Status report about Chernobyl and reindeer husbandry in Sweden including participants' discussion.Abstract in Swedish / Sammanfattning: Den 1 juli hojdes grånsvårdet for Cs-137 i bl a renkott från 300 till 1 500 Bq/kg. Efter hojningen av grånsvårdet friklassades nåstan alla samebyar i Norrbottens lån under sarvslakten. Samtliga fjållsamebyar i Norrbottens lån utom den sydligaste år tills vidare helt friklassade. Tre samebyar i sodra delen av Jåmtlands lån var friklassade under sarvslakten. I ovrigt omfattas all renslakt i Våsterbottens och Jåmtlands lån av kontroll betråffande Cs-137. Under juli - aug i år var cesiumhalten lågre ån vid motsvarande tidpunkt i f jol (tabell 1 och figur 1). Under juli - aug slaktades drygt 1 000 renar i skogslandet i sodra delen av Våsterbottens lån (tabell 3). Fr.o.m. andra veckan i juli godkåndes de fiesta slaktkropparna. Halveringstiden for Cs-137 i renarna, som betade i skogslandet kring inlandsbanan i sodra delen av Våsterbottenslån, har beråknats till ca en vecka. Genom tidigarelåggning av sarvslakter i Våsterbottens lån (tabell 3) och norra delen av Jåmtlands lån (tabell 5) minskades kassationen med ett par tusen slaktkroppar. Under senare delen av september steg cesiumhalten till ungefår samma nivå som i f jol. En långsiktig prognos har utarbetats betråffande halten Cs-137 i renar på naturbete. Prognosen visar att omfattande åtgårder kommer att behova vidtagas under de nårmaste 15 - 25 åren om ren-kottet från samebyarna i sodra delen av Våsterbottens lån och norra delen av Jåmtlands lån skall kunna god-kånnas som livsmedel vid ett riktvårde på 1 500 Bq Cs-137/kg kott

The determination of the infrared radiative lifetimes of a vibrationally excited neutral molecule using stimulated-emission-pumping, molecular-beam time-of-flight.

The authors present a new experimental method for measurement of collision-free infrared radiative lifetimes for single quantum states of a vibrationally excited sample. This method provides a more direct route to the infrared Einstein A coefficients than has been previously possible. Results for NO(X (2) Pi upsilon=21 and upsilon=7) are presented. Comparison to results of ab initio calculations shows excellent agreement. A controversy regarding the relative intensities of first overtone and fundamental emission intensities in NO is laid to rest. The most complete least squares analysis of existing data was carried out to derive the electric dipole moment function (EDMF) to an accuracy of +/-0.02 D between 0.9 and 1.7 Angstrom

Cross-lingual searching and visualization for greek and latin and old norse texts

We explore approaches to multi--lingual information retrieval for Greek, Latin, and Old Norse texts and an innovative visualization facility for the results

Harvsådd i konventionella och plöjningsfria bearbetningssystem

I en serie med långliggande försök jämfördes två storruteled (plöjning till 25 cm djup respektive stubbearbetning till 13 cm djup) och två småruteled (konventionell såbäddsberedning och sådd respektive harv sådd) för att testa om en reducering av antalet överfarter minskar de negativa effekter av packning av centrala matjorden som förknippas med plöjningsfri odling. Skörden bestämdes varje år på alla platserna. En undersökning av jordens fysikaliska och kemiska egenskaper samt rotfördelning genomfördes 1991 på en av de fyra försöksplatserna. - Bearbetningsdjup, aggregatstorleksfördelning och vattenhalt i såbädden och i såbäddens botten var liknande i de olika leden medan såbäddens botten var jämnare i det oplöjda ledet. Det påverkade ej grödans uppkomst, som var liknande mellan leden. - Andelen porer > 100 µm, porkontinuitet, mättad vattengenomsläpplighet och luftgenomsläpplighet påverkades positivt av plöjningsfri odling jämfört med konventionell bearbetning. - Skrymdensitet, packningsgrad och penetrometermotstånd var liknande i bearbetningssystemen i nivån 0-13 cm, men signifikant högre i oplöjda led i nivån 13-25 cm, där rotdensiteten var signifikant lägre. - Kalium och kol var koncentrerade till de övre 13 cm i oplöjda rutor, medan fosfor och pH ej påverkades av bearbetningssystemen. - Harvsådd gav 2 % högre skörd än konventionell såbäddsberedning och verkar vara ett gott alternativ till konventionell såbäddsberedning, men andra metoder för att reducera packningen av jorden, som till exempel däck med extremt låga tryck, bör testas

Numerical Studies of a Confocal Resonator Pick-Up with FEMLAB

Diagnostic devices aimed at measuring beam profiles in high intensity accelerators are often perturbed by microwave fields generated by the beam itself upstream of the detection device, which propagate inside the vacuum pipe. These parasitic waveguide modes can significantly reduce the signal-to-noise ratio and thus the sensitivity of the beam monitor. This warrants investigation of detection devices that are sensitive to the direct electromagnetic fields of the beam, but largely ignore the parasitic waveguide modes. A new pick-up based on a confocal resonator configuration situated transversely to the direction of propagation of the beam is currently under development at Uppsala University, Sweden. Since a confocal resonator can have a high quality factor for the diffraction losses, then reciprocity suggests that it only couples weakly to external fields while keeping anyway a significant coupling to the direct fields of the beam. Numerical simulations were performed with FEMLAB to better characterize the electromagnetic properties of a confocal resonator pick-up to be operated in the multi-GHz range, especially in terms of eigen-frequencies and coupling to external electromagnetic fields. Our results were then compared to analytical predictions and a good agreement was found, despite a few limitations in the computation of the resonant modes. Having recently built a first confocal resonator prototype, we also performed experimental cross-checks of our numerical studies with a microwave network analyzer. Our results are presented in detail in this report and we discuss further applications of the confocal resonator microwave pick-up

Direct evidence of terahertz emission arising from anomalous Hall effect

A detailed understanding of the different mechanisms being responsible for terahertz (THz) emission in ferromagnetic (FM) materials will aid in designing efficient THz emitters. In this report, we present direct evidence of THz emission from single layer Co$_{0.4}$Fe$_{0.4}$B$_{0.2}$ (CoFeB) FM thin films. The dominant mechanism being responsible for the THz emission is the anomalous Hall effect (AHE), which is an effect of a net backflow current in the FM layer created by the spin-polarized current reflected at the interfaces of the FM layer. The THz emission from the AHE-based CoFeB emitter is optimized by varying its thickness, orientation, and pump fluence of the laser beam. Results from electrical transport measurements show that skew scattering of charge carriers is responsible for the THz emission in the CoFeB AHE-based THz emitter.Comment: 5 pages, 4 figure

X-irradiation of cells on glass slides has a dose doubling impact

Immunofluorescence detection of γH2AX foci is a widely used tool to quantify the induction and repair of DNA double-strand breaks (DSBs) induced by ionising radiation. We observed that X-irradiation of mammalian cells exposed on glass slides induced twofold higher foci numbers compared to irradiation with γ-rays. Here, we show that the excess γH2AX foci after X-irradiation are produced from secondary radiation particles generated from the irradiation of glass slides. Both 120 kV X-rays and 137Cs γ-rays induce ∼20 γH2AX foci per Gy in cells growing on thin (∼2 μm) plastic foils immersed in water. The same yield is obtained following γ-irradiation of cells growing on glass slides. However, 120 kV X-rays produce ∼40 γH2AX foci per Gy in cells growing on glass, twofold greater than obtained using cells irradiated on plastic surfaces. The same increase in γH2AX foci number is obtained if the plastic foil on which the cells are grown is irradiated on a glass slide. Thus, the physical proximity to the glass material and not morphological differences of cells growing on different surfaces accounts for the excess γH2AX foci. The increase in foci number depends on the energy and is considerably smaller for 25 kV relative to 120 kV X-rays, a finding which can be explained by known physical properties of radiation. The kinetics for the loss of foci, which is taken to represent the rate of DSB repair, as well as the Artemis dependent repair fraction, was similar following X- or γ-irradiation, demonstrating that DSBs induced by this range of treatments are repaired in an identical manner

The use of an artificial nucleotide for polymerase-based recognition of carcinogenic O6-alkylguanine DNA adducts.

Enzymatic approaches for locating alkylation adducts at single-base resolution in DNA could enable new technologies for understanding carcinogenesis and supporting personalized chemotherapy. Artificial nucleotides that specifically pair with alkylated bases offer a possible strategy for recognition and amplification of adducted DNA, and adduct-templated incorporation of an artificial nucleotide has been demonstrated for a model DNA adduct O(6)-benzylguanine by a DNA polymerase. In this study, DNA adducts of biological relevance, O(6)-methylguanine (O(6)-MeG) and O(6)-carboxymethylguanine (O(6)-CMG), were characterized to be effective templates for the incorporation of benzimidazole-derived 2'-deoxynucleoside-5'-O-triphosphates ( BENZI: TP and BIM: TP) by an engineered KlenTaq DNA polymerase. The enzyme catalyzed specific incorporation of the artificial nucleotide BENZI: opposite adducts, with up to 150-fold higher catalytic efficiency for O(6)-MeG over guanine in the template. Furthermore, addition of artificial nucleotide BENZI: was required for full-length DNA synthesis during bypass of O(6)-CMG. Selective incorporation of the artificial nucleotide opposite an O(6)-alkylguanine DNA adduct was verified using a novel 2',3'-dideoxy derivative of BENZI: TP. The strategy was used to recognize adducts in the presence of excess unmodified DNA. The specific processing of BENZI: TP opposite biologically relevant O(6)-alkylguanine adducts is characterized herein as a basis for potential future DNA adduct sequencing technologies