361 research outputs found
Clover content and yield of swards on organic farms - maintenance and estimation
Grassland production based on legumes is an essential part of the productivity and economy of the organic farming systems. The clover content is an important factor in organic grassland management to optimize the yield, feed value and pre-crop effect of ley.
The ley yield and clover content of one-, two- and three-year-old leys were determined on eight organic farms in 1998. Two-year-old leys produced the highest (6500 kg/ha dm) and three-year-old leys (4900 kg/ha dm) the lowest yields, with no significant differences between one- and two-year-old leys. The clover content (20-80 % of dm) diminished to the same extent as the yields.
Because the ley samples from the organic farms gave strong evidence of decreasing yield level and clover content in the 3-year-old leys, we started to develop a technique to maintain the ley productivity in older swards. This technique includes oversowing of clover in the spring of the second ley year and utilization of lime-pelleted, pre-inoculated seed. Lime-pelleted, pre-inoculated clover seed oversown at different times in spring were compared with the aim of developing an oversowing method for Finnish conditions. The preliminary results do not show any differences, but studies are ongoing
Structural and metamorphic evolution of the Turku migmatite complex, southwestern Finland
The Turku migmatite complex in southwestern Finland is a representative area for the type of tectonic and metamorphic evolution seen within the Palaeoproterozoic Svecofennian Orogen in southern Finland. The orogeny can be divided into early, late and postorogenic stages. The early orogenic structural evolution of the crust is expressed by a D/D deformation recorded as bedding-parallel S mica foliation deformed by tight to isoclinal D folds with subhorizontal axial planes and a penetrative S axial plane foliation. Syntectonic ca. 1890-1870 Ma tonalites were emplaced during D as sheet intrusions. This deformation is attributed to thrust tectonics and thickening of the crust. The late orogenic structural evolution produced the main D folding, which transposed previous structures into a NE-SW trend. The doubly plunging fold axis produced dome-and-basin structures. The attitude of the F folds varies from upright or slightly overturned to locally recumbent towards the NW. Granite dikes were intruded along S axial planes. Large D fold limbs are often strongly deformed, intensively migmatized and intruded by garnet- and cordierite-bearing granites. These observations suggest that these potassium-rich granites, dated at 1840-1830 Ma, were emplaced during D. This late orogenic NW-SE crustal shortening further contributed to crustal thickening. Subvertical D shear zones that cut all previous rock types possibly controlled the emplacement of postorogenic granitoids. Steeply plunging lineations on D shear planes suggest vertical displacements during a regional uplift stage. Metamorphic grade increases from cordierite-sillimanite-K-feldspar gneisses in the northwest and from muscovite-quartz±andalusite rocks in the southeast to high-temperature granulite facies migmatites in the middle of the study area. Block movements during D caused the observed differences in metamorphic grade. Garnet and cordierite are mostly breakdown products of biotite and sillimanite and their growth is mainly syntectonic with D; they are elongated within the S plane and deformed by D folds. Leucosome veins were already produced during D, but in situ melting began during D producing granitic leucosomes with euhedral garnet and cordierite along the axial planes of F. Garnet is typically altered to cordierite and plagioclase in the presence of sillimanite, indicating decompression close to the temperature maximum. Pressure and temperature estimates from garnet and cordierite indicate that the granulites reached temperatures in excess of 800°C at approximately 6 kbar pressure while the adjacent amphibolite facies rocks crystallized at 100-150°C and 1-2 kbar lower temperatures and pressures. Therefore, the granulite areas represent the deepest structural levels in the area. Structural and metamorphic observations indicate that peak metamorphism was reached during the compressional late orogenic D stage ca. 1840-1830 Ma ago. Crustal thickening simultaneous with thinning of the mantle lithosphere may explain this kind of tectono-metamorphic evolution.</p
Svecofennian magmatic and metamorphic evolution in southwestern Finland as revealed by U-Pb zircon SIMS geochronology
Zircons from six samples collected from igneous and metamorphic rocks were dated using the NORDSIM ion microprobe, in order to investigate the tectonic evolution of the Palaeoproterozoic Svecofennian Orogen in southwestern Finland. These rocks represent pre-collisional, collisional and post-collisional stages of the orogeny. The ion microprobe results reveal two age groups of granodioritic-tonalitic rocks. The intrusions have different tectonic settings: the OrijĂ€rvi granodiorite represents pre-collisional 1.91-1.88 Ga island-arc-related magmatism and yielded an age of 1898 ± 9 Ma, whereas the collision-related Masku tonalite was dated at 1854 ± 18 Ma. The latter age accords with more accurate previous conventional zircon age data and constrains the emplacement age of collisional granitoids to â 1.87 Ga. This is interpreted to reflect the collision between the Southern Svecofennian Arc Complex with the Central Svecofennian Arc complex and the formation of a suture zone between them during D2 deformation. Granulite facies metamorphism in the Turku area was dated at 1824 + 5 Ma using zircons from leucosome in the Lemu metapelite. This age constrains D3 folding related to post-collisional crustal shortening in this area. Crustal melting continued until â 1.81 Ga, as indicated by the youngest leucosome zircons and metamorphic rims of enderbite zircons. New metamorphic zircon growth took place in older granitoids at granulite facies, but not at amphibolite facies. Detrital zircons with ages between 2.91 and 1.97 Ga were found in the mesosome of the Lemu metapelite and 2.64-1.93 Ga inherited cores were found in the 1.87 Ga Masku tonalite. © 2002 Elsevier Science B.V. All rights reserved.</p
Super star clusters and Supernovae in interacting LIRGs unmasked by NIR adaptive optics
We report on an on-going near-IR adaptive optics survey targeting interacting
luminous IR galaxies. High-spatial resolution NIR data are crucial to enable
interpretation of kinematic, dynamical and star formation (SF) properties of
these very dusty objects. Whole progenitor nuclei in the interactions can be
missed if only optical HST imaging is used. Here we specifically present the
latest results regarding core-collapse supernovae found within the highly
extincted nuclear regions of these galaxies. Direct detection and study of such
highly obscured CCSNe is crucial for revising the optically-derived SN rates
used for providing an independent measurement of the SF history of the
Universe. We also present thus-far the first NIR luminosity functions of super
star cluster (SSC) candidates. The LFs can then be used to constrain the
formation and evolution of SSCs via constraints based on initial mass functions
and cluster disruption models.Comment: 6 pages. To appear in proceedings of 'Galaxies and their Masks'
(Namibia, April 2010), published by Springer, New York, eds. D.L. Block, K.C.
Freeman, I. Puerar
Koirat koulussa:diskurssianalyysi Opetushallituksen ohjeistuksesta koira-avusteiselle toiminnalle oppilaitoksissa
TiivistelmÀ. ElÀinavusteisella työskentelyllÀ tarkoitetaan elÀinten kanssa suoritettavaa toimintaa. Sen pÀÀmÀÀrÀ on laaja henkilökohtaisen hyvinvoinnin parantamisesta vuorovaikutustaitojen kehittymiseen. Se jaetaan neljÀÀn eri osa-alueeseen, jotka ovat elÀinavusteinen toiminta, terapia, pedagogiikka ja valmennus. Tutkimukseni keskittyy koira-avusteiseen pedagogiikkaan. SillÀ tarkoitetaan suunniteltua, tavoitteellista ja ammattimaista opetusta. Sen on osoitettu vaikuttavan positiivisesti oppilaiden oppimismahdollisuuksiin, kokonaisvaltaiseen kÀyttÀytymiseen ja sosiaalisiin taitoihin. Koira-avusteisen pedagogiikan avulla pystytÀÀn vÀhentÀmÀÀn ahdistuneisuutta sekÀ lisÀÀvÀn haluttua kÀyttÀytymistÀ, itsetuntoa ja innokkuutta. Sen avulla voidaan harjoitella empatiakykyÀ, vastuunottoa ja kunnioitusta muita kohtaan.
Tutkimuksessa aineistona kĂ€ytĂ€n Opetushallituksen laatimaa ohjeistusta koira-avusteisesta toiminnasta oppilaitoksille. Se on tehty yhteistyössĂ€ Allergia-, Iho- ja Astmaliitto ry:n, Koirat kuntoutus- ja kasvatustyössĂ€ ry:n, Suomen Kennelliitto ry:n sekĂ€ koulutuksen jĂ€rjestĂ€jĂ€n edustajan kanssa. Tavoitteena oli selvittÀÀ, millaisia diskursseja aineistossa muodostuu ja millaisia subjektipositioita aineistossa tuotetaan opettajan, oppilaan ja koiran nĂ€kökulmista. Aineistosta tunnistin neljĂ€ diskurssia, jotka ovat arvo-, terveys ja hyvinvointi -, turvallisuus- sekĂ€ soveltuvuusdiskurssi. Subjektipositioita löytyi useita. Opettajasta tuotettiin kolme subjektipositiota, jotka ovat âtiedonvĂ€littĂ€jĂ€â, âvastuunkantajaâ ja âselvittelijĂ€â. Oppilaasta tuotetut subjektipositiot ovat âei terveâ, âkohdeâ ja âiloinen lapsiâ. Koirasta tuotettiin viisi subjektipositiota, jotka ovat: âhaittaesineâ, âsoveltuvaesineâ, âhyvinvoivaâ, âammattilainenâ ja âilon tuojaâ.
Diskurssianalyysitulokset viittaavat Opetushallituksen ohjeistuksessa huomion kiinnittyvÀn oppijoiden oikeuteen oppia. Koiran kÀyttöÀ pidetÀÀn toissijaisena opetusmetodina, jota opettaja hyödyntÀÀ. Koirasta puhutaan opettajan pedagogisena työvÀlineenÀ ja esineenÀ, jonka soveltuvuutta testataan. SiitÀ puhutaan myös ilon ja lÀheisyyden tuojana. LisÀtutkimusta olisi hyvÀ tehdÀ koiran nÀkökulmasta. Esimerkiksi siitÀ, miten oppilaat vaikuttavat koiraan ja sen hyvinvointiin
Terminating ley with mid-summer bare fallow controls Elymus repens
The results of this study suggest that mid-summer bare fallow is a relative effective way to reduce the amount of Elymus repens when terminating ley. Early started stubble cultivation is also less sensitive to moist weather, leaving more time for exhausting the rhizome reserves of E. repens. Stubble cultivation and catch crop do increase the costs but not as much as bare fallowing for the whole summer would do. Additionally, mid summer bare fallow allows harvesting one forage yield prior to bare fallowing
An Overdensity of Extremely Red Objects Around Faint Mid-IR galaxies
We have searched for Extremely Red Objects (EROs) around faint mid-IR
selected galaxies in ELAIS fields. We find a significant overdensity, by
factors of 2 to 5, of these EROs compared to field EROs in the same region and
literature random field ERO counts. The excess is similar to that found
previously in the fields of known high redshift quasars and AGN. While with the
present data it cannot be definitely shown whether the overdensity is
physically connected to the mid-IR source, a derived radial distribution does
suggest this. The fraction of EROs among K-selected galaxies is high in the
mid-IR fields in agreement with the picture that the EROs responsible for the
overdensity are members of high redshift clusters of galaxies. We find R-K>5
selected EROs to be more clustered around the mid-IR galaxies than I-K>4 EROs,
though statistics are weak because of small numbers. However, this would be
consistent with a cluster/galaxy group scenario if, as we argue, the former
colour selection finds preferentially more strongly clustered early type
galaxies, whereas the latter selection includes a larger fraction of dusty
EROs. Finally, using the mid-IR data, we are able to limit the fraction of
ULIRG type very dusty EROs at K<18 magnitude to less than 10% of the total ERO
population.Comment: A&A, accepted, 13 pages and 5 ps-fig
Adaptive Optics Discovery of Supernova 2004ip in the Nuclear Regions of the Luminous Infrared Galaxy IRAS 18293-3413
We report a supernova discovery in Ks-band images from the NAOS CONICA
adaptive optics (AO) system on the ESO Very Large Telescope (VLT). The images
were obtained as part of a near-infrared search for highly-obscured supernovae
in the nuclear regions of luminous and ultraluminous infrared galaxies. SN
2004ip is located within a circumnuclear starburst at 1.4 arcsec (or 500 pc)
projected distance from the K-band nucleus of the luminous infrared galaxy IRAS
18293-3413. The supernova luminosity and light curve are consistent with a
core-collapse event suffering from a host galaxy extinction of up to about 40
magnitudes in V-band which is as expected for a circumnuclear starburst
environment. This is the first supernova to be discovered making use of AO
correction and demonstrates the potential of the current 8-meter class
telescopes equipped with AO in discovering supernovae from the innermost
nuclear regions of luminous and ultraluminous infrared galaxies.Comment: 4 pages, 3 figures, ApJ Letters (accepted
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