The 1 um discontinuity in the Extragalactic Background Light spectrum: an artefact of foreground subtraction

Several recent papers claim the detection of a near infrared Extragalactic Background Light (EBL) intensity at 1.25 - 4 um that exceeds the integrated light of galaxies by factors of >3. When combined with a claimed optical detection of the EBL at 0.80 um the EBL excess emission spectrum has a discontinuity at ~1 um. This discontinuity has given rise to an interpretation in terms of ultraviolet radiation emanating from the first generation of massive stars at redshifts of 7 - 20 (so called Population III stars). The interpretation of the NIR excess emission as being of extragalactic origin depends crucially on the model used in the subtraction of the Zodiacal Light, the dominant foreground contaminant. We estimate the Zodiacal Light at 0.80 um using on the one hand the measurement by Bernstein et al.,2002, ApJ, 571,85), with corrections for some omitted effects of atmospheric scattering and calibration, and on the other hand the model of Kelsall et al.,1998, ApJ, 508,44). There is in neither case any evidence for a step in the EBL at ~1 um. We emphasize that in order to avoid systematic effects it is essential to use the same Zodiacal Light model (Kelsall et al. 1998) for both the NIR (1.25 - 4 um) and optical (0.80 um) data. We emphasize, however, that our analysis does not allow a statement on the overall level of the NIR EBL. The contribution of the Diffuse Galactic Light to the ``EBL excess'' emission is estimated. It is found to be significant at 3 - 4 um and should be carefully evaluated in future measurements which aim at detecting an EBL signal at the level of ~10 nW m^-2 sr^-1, i.e. at the level of the integrated light of (known) galaxies.Comment: 7 pages, 1 figure, accepted for publication in MNRA

Spectroscopy of diffuse light in dust clouds. Scattered light and the solar neighbourhood radiation field

The optical surface brightness of dark nebulae is mainly due to scattering of integrated starlight by classical dust grains. It contains information on the impinging interstellar radiation field, cloud structure, and grain scattering properties. We have obtained spectra of the scattered light from 3500 to 9000 Angstrom in two globules, the Thumbprint Nebula and DC303.8-14.2. We use observations of the scattered light to study the impinging integrated starlight spectrum as well as the scattered H-alpha and other line emissions from all over the sky. We search also for the presence of other than scattered light in the two globules. We obtained long-slit spectra encompassing the whole globule plus adjacent sky in a one-slit setting, thus enabling efficient elimination of airglow and other foreground sky components. We calculated synthetic integrated starlight spectra for the solar neighbourhood using HIPPARCOS-based stellar distributions and the spectral library of Pickles. Spectra are presented separately for the bright rims and dark cores of the globules. The continuum spectral energy distributions and absorption line spectra can be well modelled with the synthetic integrated starlight spectra. Emission lines of H-alpha + NII, H-beta, and SII are detected and are interpreted in terms of scattered light plus an in situ warm ionized medium component behind the globules. We detected an excess of emission over the wavelength range 5200-8000 Angstrom in DC303.8-14.2 but the nature of this emission remains open

Ammonia volatilization, nitrogen in soil, and growth of barley after application of peat manure and pig slurry

Peat is added to manure, because its low pH and capacity to adsorb ammonia (NH3) give it potential to reduce nitrogen (N) loss. Peat manure was prepared by mixing pig slurry with moderately humified Sphagnum peat. Less than 1% of applied ammoniacal N was volatilized as NH3 from peat manure and pig slurry within 8 h of surface application on clay loam soil according to JTI method. Incorporated manures showed even smaller N loss. The low volatilization was due to the adsorption of manure ammoniacal N by peat, and the infiltration of slurry into harrowed, moist clay soil. In another experiment, peat manure was applied on polypropylene fabric without soil contact. Within the first 3 days there was only 9% reduction in the ammoniacal N of peat manure, but the major part of it was lost during several weeks of dry and warm weather. Peat manure did not cause any major improvements on the growth and N uptake of spring barley in spring and early summer as compared with slurry. Moisture deficit limited the availability of ammoniacal N of manures. As compared with surface application, incorporation of manures increased nitrification of ammonium in the soil, and dry matter mass (19–73%) and N uptake of barley. Supplementing manures with inorganic NPK fertilizer increased both dry matter mass (40–98%) and N concentration of barley stand

Spring barley yield and nitrogen recovery after application of peat manure and pig slurry

The effectiveness of peat manure, manufactured of pig slurry and moderately humified Sphagnum peat (slurry:peat ca. 1:1.5 v/v), as nitrogen (N) source for spring barley was investigated in a four.year field experiment on a clay loam soil in south-western Finland. Pig slurry, NPK fertilizer and plain peat were used as references. Manures were incorporated before sowing or surface-applied after sowing in spring at an ammoniacal N rate of.54.106 kg.ha-1 with or without supplementary NPK fertilizer (40.kg N.ha-1). Soil moisture conditions were varied by different irrigation treatments. Peat manure produced 5.15% higher grain yields than pig slurry, with the largest difference after surface application. Incorporation was more important for slurry than for peat manure in increasing N uptake and yield. Soil moisture deficit in spring and early summer limited the availability of manure N. Part of the manure N that was not available in the early growing period was apparently taken up by the crop later. Consequently, N concentration tended to be higher with lower yields, and differences in the recovery of manure N were smaller than the differences in grain yield. Supplementation of manures with inorganic fertilizer N increased yield by 37%, on average, and improved the N recovery

Clover rot (Sclerotinia trifolium) and Fusarium fungi in organic red clover in Finland

Sclerotinia trifolium is economically one of the most important pathogens of red clover in Europe and North America, while many Fusarium species can cause root rot in red clover in certain environmental conditions. During the years 2003-2004 S. trifolium was found only in the Northern and Eastern part of Finland, although in 1960's it was common everywhere in Finland

Letter to the editor: Consistency of LPC+Ch

summary:In his paper [Kybernetika 31, No. 1, 99–106 (1995; Zbl 0857.03042)], E. Turunen says in the corollary on p. 106: “Notice that the third last line on page 195 in [J. K. Mattila, “Modifier logic”, in: J. Kacprzyk (ed.) et al., Fuzzy logic for the management of uncertainty. New York: Wiley. 191–209 (1992)] stating that LPC+Ch calculus is consistent is not correct.” The system LPC+Ch is consistent, which can be seen quite trivially