VAP-1 in Leukocyte Trafficking

The extravasation of leukocytes from the blood stream into the tissues is a prerequisite for adequate immune surveillance and immune reaction. The leukocyte movement from the bloodstream into the tissues is mediated by molecular bonds. The bonds are formed between adhesion molecules on endothelial cells and their counterparts expressed on leukocytes. Vascular adhesion protein-1 (VAP-1) is an endothelial adhesion molecule mediating leukocyte interactions with endothelium. It is also an enzyme having semicarbazide sensitive amine oxidase (SSAO) activity. The SSAOactivity catalyses deamination of primary amines into corresponding aldehyde and during the enzymatic reaction hydrogen peroxide and ammonia are produced. The aim of this study was to investigate the relationship between the adhesive and enzymatic activities of VAP-1. The role of VAP-1 in leukocyte traffic was studied in vivo under normal and pathological conditions in VAP-1 deficient mice. The results from in vitro flow-based assays indicated that VAP-1 uses both SSAOactivity and its adhesive epitope to bind leukocytes, and both are perquisites for VAP-1 mediated adhesion. Furthermore, in vivo results demonstrated that leukocyte trafficking was impaired in vivo by deleting VAP-1 or inhibiting SSAO-activity. There was impairment in lymphocyte recirculation as well as leukocyte accumulation into the inflamed area. Moreover, the VAP-1 deficient mice did not show generalized defects in antimicrobial responses, whereas significant reduction in tumor progression and neovascularization was observed. These results indicate that VAP-1 could be used as a target in anti-adhesive therapies either by blocking its adhesive epitope with antibodies or by inhibiting its SSAO-activity using inhibitors. Moreover, targeting of VAP-1 may provide a new way of inhibiting neovascularization in tumors.

Pk-yritysten rahoituspalveluiden kehittäminen Varkauden talousalueella

Tässä tutkimuksessa selvitettiin Varkauden talousalueen pk-yritysten rahoituspalveluiden kehitystarpeita. Kuvailevaa tutkimusta käyttämällä selvitettiin mitä ongelmakohtia yritykset näkevät rahaliikenteessään, miten rahoitusrakennetta suunnitellaan ja minkälaisia tuotteita yrityksillä on käytössään. Mittareina tutkimuksessa käytettiin mm. kasvutavoitetta, pääomarakennetta ja tuottovaatimusten muodostamista. Tavoitteena oli tutkia mitkä tekijät vaikuttavat sijoituspäätöksentekoon ja mitä tekijöitä arvostetaan pankista saadussa palvelussa. Tutkimukseen valittiin Varkauden talousalueen suurimmat ja parhaan luottoluokituksen omaavat yritykset. Aineisto kerättiin luomalla sähköinen kyselylomake, joka lähetettiin 48 yritykseen tammikuussa 2009. Tutkimustulosten mukaan yritykset näkivät suurimmat kehitystarpeet sähköisessä taloushallinnossa, eri investointirahoitusvaihtoehdoissa ja julkisten sekä yksityisten rahoittajien yhteistyössä. Parempaa rahoitusneuvontaa kaivattiin investointirahoitukseen ja yrityskauppoihin liittyen. Suurimmalla osalla yrityksistä oli selkeät kasvutavoitteet sekä suunniteltu pääomarakenne. Suurimpia puutteita havaittiin mm. korkosuojaus- ja kassanhallinnan ratkaisuissa. Varainhoidon tuotteista mielenkiintoisimpana nähtiin pääomaturvatut ja kiinteää tuottoa maksavat vaihtoehdot. Sijoituspäätöksiin vaikuttavat paljon pankin luotettavuus sekä toimihenkilön asiantuntemus. Vastaavasti sijoituspäätös voi jäädä tekemättä, mikäli tuote on liian monimutkainen tai prosessi vaatii paljon aikaa ja paneutumista. Pankin palveluissa arvostetaan niin ikään luotettavuutta, helppoa asiointia sekä henkilökohtaista palvelua. Vastaajien koulutustaustalla ei näytä valittujen mittareiden perusteella olevan vaikutusta rahoitusosaamiseen. Alueella rahoitusongelmia kohdanneista yrityksistä lähes kaikki olivat kasvuhakuisia.

Electroluminescence of silicon- and some metal oxides

In the present work electroluminescence in Si-SiO2 structures has been investigated. Electroluminescence has been recorded in the range of 250-900 nm in a system of electrolyte-insulator-semiconductor at the room temperature. The heating process of electrons in SiO2 was studied and possibility of separation it into two phases has been shown. The nature of luminescence centers and the model of its formation were proposed. This paper also includes consideration of oxide layer formation. Charge transfer mechanisms have been attended as well. The nature of electroluminescence is understood in detail. As a matter of fact, electron traps in silicon are the centers of luminescence. Electroluminescence occurs when electrons move from one trap to another. Thus the radiation of light quantum occurs. These traps appear as a result of the oxide growth. At the same time the bonds deformation of silicon atoms with SiOH groups is not excludes. As a result, dangling bonds are appeared, which are the trapping centers or the centers of luminescence.

Active sulphide mine tailings impoundments as sources of contaminated drainage: controlling factors, methods of characterisation and geochemical constraints for mitigation

Low quality mine drainage from tailings facilities persists as one of the most significant global environmental concerns related to sulphide mining. Due to the large variation in geological and environmental conditions at mine sites, universal approaches to the management of mine drainage are not always applicable. Instead, site-specific knowledge of the geochemical behaviour of waste materials is required for the design and closure of the facilities. In this thesis, tailings-derived water contamination and factors causing the pollution were investigated in two coeval active sulphide mine sites in Finland: the Hitura Ni mine and the Luikonlahti Cu-Zn-Co-Ni mine and talc processing plant. A hydrogeochemical study was performed to characterise the tailingsderived water pollution at Hitura. Geochemical changes in the Hitura tailings were evaluated with a detailed mineralogical and geochemical investigation (solid-phase speciation, acid mine drainage potential, pore water chemistry) and using a spatial assessment to identify the mechanisms of water contamination. A similar spatial investigation, applying selective extractions, was carried out in the Luikonlahti tailings area for comparative purposes (Hitura low-sulphide tailings vs. Luikonlahti sulphide-rich tailings). At both sites, hydrogeochemistry of tailings seepage waters was further characterised to examine the net results of the processes observed within the impoundments and to identify constraints for water treatment. At Luikonlahti, annual and seasonal variation in effluent quality was evaluated based on a four-year monitoring period. Observations pertinent to future assessment and mine drainage prevention from existing and future tailings facilities were presented based on the results. A combination of hydrogeochemical approaches provided a means to delineate the tailings-derived neutral mine drainage at Hitura. Tailings effluents with elevated Ni, SO₄ ^2- and Fe content had dispersed to the surrounding aquifer through a levelled-out esker and underneath the seepage collection ditches. In future mines, this could be avoided with additional basal liners in tailings impoundments where the permeability of the underlying Quaternary deposits is inadequate, and with sufficiently deep ditches. Based on the studies, extensive sulphide oxidation with subsequent metal release may already initiate during active tailings disposal. The intensity and onset of oxidation depended on e.g. the Fe sulphide content of the tailings, water saturation level, and time of exposure of fresh sulphide grains. Continuous disposal decreased sulphide weathering in the surface of low-sulphide tailings, but oxidation initiated if they were left uncovered after disposal ceased. In the sulphide-rich tailings, delayed burial of the unsaturated tailings had resulted in thick oxidized layers, despite the continuous operation. Sulphide weathering and contaminant release occurred also in the border zones. Based on the results, the prevention of sulphide oxidation should already be considered in the planning of tailings disposal, taking into account the border zones. Moreover, even lowsulphide tailings should be covered without delay after active disposal ceases. The quality of tailings effluents showed wide variation within a single impoundment and between the two different types of tailings facilities assessed. The affecting factors included source materials, the intensity of weathering of tailings and embankment materials along the seepage flow path, inputs from the process waters, the water retention time in tailings, and climatic seasonality. In addition, modifications to the tailings impoundment may markedly change the effluent quality. The wide variation in the tailings effluent quality poses challenges for treatment design. The final decision on water management requires quantification of the spatial and seasonal fluctuation at the site, taking into account changes resulting from the eventual closure of the impoundment. Overall, comprehensive hydrogeochemical mapping was deemed essential in the identification of critical contaminants and their sources at mine sites. Mineralogical analysis, selective extractions, and pore water analysis were a good combination of methods for studying the weathering of tailings and in evaluating metal mobility from the facilities. Selective extractions with visual observations and pH measurements of tailings solids were, nevertheless, adequate in describing the spatial distribution of sulphide oxidation in tailings impoundments. Seepage water chemistry provided additional data on geochemical processes in tailings and was necessary for defining constraints for water treatment.