The Tourism-Development Nexus in Namibia : A Study on National Tourism Policy and Local Tourism Enterprises' Policy Knowledge

The tourism development nexus in southern Africa involves highly topical issues related to tourism planning, power relations, community participation, and natural resources. Namibia offers a particularly interesting context for the study of these issues due to its colonial legacy, vast tourism potential, recently adopted tourism policy and community-based approaches to tourism and natural resource management. This study is an interdisciplinary endeavour to analyse the role of tourism in Namibia s post-apartheid transformation process by focusing on Namibian tourism policy and local tourism enterprises' policy knowledge. Major attention is paid to how the tourism policy's national development objectives are understood and conceptualised by the representatives of different tourism enterprises and the ways in which they relate to the practical needs of the enterprises. Through such local policy knowledge the study explores various opportunities, challenges and constraints related to the promotion of tourism as a development strategy. The study utilises a political economy approach to tourism and development through three current and interrelated discourses which are relevant in the Namibian context. These are tourism, power and inequality, tourism and sustainable development, and tourism and poverty reduction. The qualitative research material was gathered in Namibia in 2006-2007 and 2008. This material consists of 34 semi-structured interviews in 16 tourism enterprises, including private trophy hunting farms and private lodges, small tour operators and community-based tourism enterprises. In addition, the research material consists of observations in the enterprises, and 37 informal and 23 expert interviews. The findings indicate that in the light of local tourism enterprises the tourism policy objectives appear more complex and ambiguous. Furthermore, they involve multiple meanings and interpretations which reflect the socio-economic stratification of the informants and Namibian society, together with the professional stratification of the tourism enterprises and restrictions on the capacity of tourism to address the development objectives. In the light of such findings it is obvious that aspects of power and inequality affect the tourism development nexus in Namibia. The study concludes that, as in the case of other southern African countries, in order to promote sustainable development and reduce poverty, Namibia should not only target tourism growth but pay attention to who benefits from that growth and how. From a political economy point of view, it is important that prevailing structural challenges are addressed equally in the planning of tourism, development and natural resource management. Such approach would help the Namibian majority to enjoy the benefits of increasing tourism in the country.

Tonically Active Kainate Receptors (tKARs) : A Novel Mechanism Regulating Neuronal Function in the Brain

Fast excitatory transmission between neurons in the central nervous system is mainly mediated by L-glutamate acting on ligand gated (ionotropic) receptors. These are further categorized according to their pharmacological properties to AMPA (2-amino-3-(5-methyl-3-oxo-1,2- oxazol-4-yl)propanoic acid), NMDA (N-Methyl-D-aspartic acid) and kainate (KAR) subclasses. In the rat and the mouse hippocampus, development of glutamatergic transmission is most dynamic during the first postnatal weeks. This coincides with the declining developmental expression of the GluK1 subunit-containing KARs. However, the function of KARs during early development of the brain is poorly understood. The present study reveals novel types of tonically active KARs (hereafter referred to as tKARs) which play a central role in functional development of the hippocampal CA3-CA1 network. The study shows for the first time how concomitant pre- and postsynaptic KAR function contributes to development of CA3-CA1 circuitry by regulating transmitter release and interneuron excitability. Moreover, the tKAR-dependent regulation of transmitter release provides a novel mechanism for silencing and unsilencing early synapses and thus shaping the early synaptic connectivity. The role of GluK1-containing KARs was studied in area CA3 of the neonatal hippocampus. The data demonstrate that presynaptic KARs in excitatory synapses to both pyramidal cells and interneurons are tonically activated by ambient glutamate and that they regulate glutamate release differentially, depending on target cell type. At synapses to pyramidal cells these tKARs inhibit glutamate release in a G-protein dependent manner but in contrast, at synapses to interneurons, tKARs facilitate glutamate release. On the network level these mechanisms act together upregulating activity of GABAergic microcircuits and promoting endogenous hippocampal network oscillations. By virtue of this, tKARs are likely to have an instrumental role in the functional development of the hippocampal circuitry. The next step was to investigate the role of GluK1 -containing receptors in the regulation of interneuron excitability. The spontaneous firing of interneurons in the CA3 stratum lucidum is markedly decreased during development. The shift involves tKARs that inhibit medium-duration afterhyperpolarization (mAHP) in these neurons during the first postnatal week. This promotes burst spiking of interneurons and thereby increases GABAergic activity in the network synergistically with the tKAR-mediated facilitation of their excitatory drive. During development the amplitude of evoked medium afterhyperpolarizing current (ImAHP) is dramatically increased due to decoupling tKAR activation and ImAHP modulation. These changes take place at the same time when the endogeneous network oscillations disappear. These tKAR-driven mechanisms in the CA3 area regulate both GABAergic and glutamatergic transmission and thus gate the feedforward excitatory drive to the area CA1. Here presynaptic tKARs to CA1 pyramidal cells suppress glutamate release and enable strong facilitation in response to high-frequency input. Therefore, CA1 synapses are finely tuned to high-frequency transmission; an activity pattern that is common in neonatal CA3-CA1 circuitry both in vivo and in vitro. The tKAR-regulated release probability acts as a novel presynaptic silencing mechanism that can be unsilenced in response to Hebbian activity. The present results shed new light on the mechanisms modulating the early network activity that paves the way for oscillations lying behind cognitive tasks such as learning and memory. Kainate receptor antagonists are already being developed for therapeutic use for instance against pain and migraine. Because of these modulatory actions, tKARs also represent an attractive candidate for therapeutic treatment of developmentally related complications such as learning disabilities.

Experimental analysis of thermo-physical processes in acoustically levitated heated droplets

An experimental setup using radiative heating has been used to understand the thermo-physical phenomena and chemical transformations inside acoustically levitated cerium nitrate precursor droplets. In this transformation process, through infrared thermography and high speed imaging, events such as vaporization, precipitation and chemical reaction have been recorded at high temporal resolution, leading to nanoceria formation with a porous morphology. The cerium nitrate droplet undergoes phase and shape changes throughout the vaporization process. Four distinct stages were delineated during the entire vaporization process namely pure evaporation, evaporation with precipitate formation, chemical reaction with phase change and formation of final porous precipitate. The composition was examined using scanning and transmission electron microscopy that revealed nanostructures and confirmed highly porous morphology with trapped gas pockets. Transmission electron microscopy (TEM) and high speed imaging of the final precipitate revealed the presence of trapped gases in the form of bubbles. TEM also showed the presence of nanoceria crystalline structures at 70 degrees C. The current study also looked into the effect of different heating powers on the process. At higher power, each phase is sustained for smaller duration and higher maximum temperature. In addition, the porosity of the final precipitate increased with power. A non-dimensional time scale is proposed to correlate the effect of laser intensity and vaporization rate of the solvent (water). The effect of acoustic levitation was also studied. Due to acoustic streaming, the solute selectively gets transported to the bottom portion of the droplet due to strong circulation, providing it rigidity and allows it become bowl shaped. (C) 2010 Elsevier Ltd. All rights reserved.

Interfacial Phenomena in Pharmaceutical Low Moisture Content Powder Processing

Powders are essential materials in the pharmaceutical industry, being involved in majority of all drug manufacturing. Powder flow and particle size are central particle properties addressed by means of particle engineering. The aim of the thesis was to gain knowledge on powder processing with restricted liquid addition, with a primary focus on particle coating and early granule growth. Furthermore, characterisation of this kind of processes was performed. A thin coating layer of hydroxypropyl methylcellulose was applied on individual particles of ibuprofen in a fluidised bed top-spray process. The polymeric coating improved the flow properties of the powder. The improvement was strongly related to relative humidity, which can be seen as an indicator of a change in surface hydrophilicity caused by the coating. The ibuprofen used in the present study had a d50 of 40 μm and thus belongs to the Geldart group C powders, which can be considered as challenging materials in top-spray coating processes. Ibuprofen was similarly coated using a novel ultrasound-assisted coating method. The results were in line with those obtained from powders coated in the fluidised bed process mentioned above. It was found that the ultrasound-assisted method was capable of coating single particles with a simple and robust setup. Granule growth in a fluidised bed process was inhibited by feeding the liquid in pulses. The results showed that the length of the pulsing cycles is of importance, and can be used to adjust granule growth. Moreover, pulsed liquid feed was found to be of greater significance to granule growth in high inlet air relative humidity. Liquid feed pulsing can thus be used as a tool in particle size targeting in fluidised bed processes and in compensating for changes in relative humidity of the inlet air. The nozzle function of a two-fluid external mixing pneumatic nozzle, typical for small scale pharmaceutical fluidised bed processes, was studied in situ in an ongoing fluidised bed process with particle tracking velocimetry. It was found that the liquid droplets undergo coalescence as they proceed away from the nozzle head. The coalescence was expected to increase droplet speed, which was confirmed in the study. The spray turbulence was studied, and the results showed turbulence caused by the event of atomisation and by the oppositely directed fluidising air. It was concluded that particle tracking velocimetry is a suitable tool for in situ spray characterisation. The light transmission through dense particulate systems was found to carry information on particle size and packing density as expected based on the theory of light scattering by solids. It was possible to differentiate binary blends consisting of components with differences in optical properties. Light transmission showed potential as a rapid, simple and inexpensive tool in characterisation of particulate systems giving information on changes in particle systems, which could be utilised in basic process diagnostics.

Itsekorjaus huumorin keinona verkkokeskustelussa

Tutkielmassa tarkastellaan itsekorjausta huumorin ja vitsailun keinona kahdenkeskisessä verkkokeskustelussa. Keskustelut käydään Messenger-pikaviestinohjelmassa, jossa keskustelijat voivat lähettää toisilleen kirjoitettuja viestejä ja olla reaaliaikaisesti vuorovaikutuksessa keskenään. Aineisto on vuosilta 2004 - 2010; kooltaan se on 25088 kilotavua (noin 2531,5 sivua tekstinkäsittelyohjelmalla kirjoitettua tekstiä). Informantteja on viisi, ja he ovat ystäviä keskenään, jolloin keskustelu on hyvin reaaliaikaista, spontaania ja vitsailevaa. Aineisto sisältää 71 tapausta, joissa itsekorjausta käytetään huumorin keinona. Tutkimusaihetta lähestytään keskustelunanalyyttisen metodin avulla. Vaikka se on puhutun kielen tutkimukseen kehitetty analyysiväline, sitä voidaan soveltaa myös verkkokeskustelun tarkastelemiseen. Keskustelunanalyyttisin keinoin pystytään selvittämään, millä keinoin keskustelijat korjaavat tahattomia kirjoitusvirheitä ja tarkoituksella väärin kirjoitettuja muotoja tai vuoroja, kun ne osallistuvat huumorin luomiseen. Tutkimus osoittaa, kuinka jo tahattoman kirjoitusvirheen tekeminen huvittaa keskustelijoita etenkin silloin, kun sanasta tulee suomen kielessä tuntematon, jolloin sen humoristisuus ei voi perustua sen merkitykseen. Lyöntivirheen seurauksena syntynyt sana voi myös olla kontekstiinsa sopimaton, minkä vuoksi se huvittaa keskustelijoita. Kirjoitusvirheellistä muotoa saatetaan käyttää lisäksi tarkoituksella myöhemmin keskustelussa huumorin keinona. Sormen lipsahdukset korjataan usein lähettämällä korvaava muoto keskusteluun ilman puhutussa keskustelussa korjausta ennakoivaa ainesta (esim. sanan katkaisu, tauko tai partikkeli eiku, tai ja siis), minkä mahdollistaa verkkokeskustelun kirjoitettu muoto: korjauksen kohde voidaan havaita aikaisemmasta näkyvissä olevasta keskustelusta. Mahdollinen korjausta implikoiva partikkeli sijoittuu esiintyessään usein vasta korjaavan aineksen jälkeen. Toisin kuin tahattomia virheitä korjattaessa, tarkoituksella väärin kirjoitettujen vitsailevien muotojen korjaus voidaan ennakoida partikkeleilla eiku tai tai, jotka osoittavat korjattavan sanan tai rakenteen sopimattomuuden kontekstiin. Humoristisuus perustuu väärän ja korjaavan muodon rinnastamiseen, ja usein ne ovatkin esimerkiksi samassa sijamuodossa tai saman verbin eri persoonamuotoja, ja niillä voidaan viitata leikkisästi samaan tarkoitteeseen. Tahallisella väärinkirjoituksella saatetaan vitsailla niin keskustelun alussa kuin missä kohtaa keskustelua ja minkälaisessa toiminnassa tahansa (esim. ehdotuksessa, kannanotossa ja ymmärrysehdokkaassa) lukuun ottamatta keskustelun lopetuksia. Keskustelija voi kumota ja osoittaa edeltävän vuoronsa olleen vitsi myös kiteytyneellä ilmauksella noei, joka on aineistossa eniten käytetty korjauskeino: se esiintyy 39 kertaa kaikista 71 tapauksesta. Ilmaus näyttää olevan erityisen käyttökelpoinen korjaustapa lyhyen muotonsa vuoksi, sillä se on nopea kirjoittaa humoristiseksi tarkoitetun viestin jälkeen vaikkakin keskustelija haluaa ensin tarkoituksella esittää olevansa jossain määrin vakavissaan korjattavassa viestissään. Noei tekee korjauksen yksin eikä tarvitse seurakseen korjaavaa ainesta, mutta toisen lausuman kanssa esiintyessään ilmaus voi kumota laajemmankin jakson edeltävästä keskustelusta. Noei:llä tehty korjaus voi kohdistua myös keskustelun moodiin, jonka ilmaus saattaa siirtää humoristiseksi tai vakavaksi.

Amplitude Frequency Response Measurement: A Simple Technique

A simple method is described to combine a modern function generator and a digital oscilloscope to configure a setup that can directly measure the amplitude frequency response of a system. This is achieved by synchronously triggering both instruments, with the function generator operated in the ``Linear-Sweep'' frequency mode, while the oscilloscope is operated in the ``Envelope'' acquisition mode. Under these conditions, the acquired envelopes directly correspond to the (input and output signal) spectra, whose ratio yields the amplitude frequency response. The method is easy to configure, automatic, time-efficient, and does not require any external control or interface or programming. This method is ideally suited to impart hands-on experience in sweep frequency response measurements, demonstrate resonance phenomenon in transformer windings, explain the working principle of an impedance analyzer, practically exhibit properties of network functions, and so on. The proposed method is an inexpensive alternative to existing commercial equipment meant for this job and is also an effective teaching aid. Details of its implementation, along with some practical measurements on an actual transformer, are presented.

Muistoja kadonneesta valtiosta: DDR:n arkipäivän muistaminen, museoiminen ja Ostalgie

Tässä pro gradu -tutkielmassa käsitellään DDR:n arkipäivän muistamista ja museoimista sekä DDR-nostalgiaa eli Ostalgieta. Tutkielmassa esitellään erilaisia näkökulmia muistin ja nostalgian muotoutumiseen ja pohditaan sitä, millä tavoin Saksan menneisyys ja historiapolitiikka ovat vaikuttaneet siihen, kuinka DDR:n menneisyyttä nykyään käsitellään. Työ perustuu Berliinissä, Saksassa huhti-heinäkuussa 2010 kerättyyn aineistoon, joka koostuu haastatteluista, vierailuista DDR:n arkipäivää käsitteleviin museoihin sekä verkkoaineistosta. DDR:n arkipäivää esittelevissä museoissa DDR:n materiaalinen menneisyys on pyritty säilyttämään, jotta muisti siitä ei katoaisi. Museoiden näyttelyt herättelevät ja ylläpitävät muistia sekä valistavat kävijöitä siitä, millaista tavallinen ja arkinen elämä DDR:ssä oli. Museot luovat korostetun ei-poliittisilla ja arkipäiväisillä näyttelyillä vastanarratiiveja viralliselle valtion DDR:stä ylläpitämälle suurnarratiiville, jossa DDR nähdään pelkkänä totalitaarisena diktatuurina ja sorron symbolina. Yhteisöpalvelu Facebookista löytyvässä keskusteluryhmä DDR Zonenkinderissä ihmiset jakavat omakohtaisia ja subjektiivisia muistojaan menneestä. Ryhmä luo vapaan ja avoimen foorumin jakaa muistoja, tuntea yhteisöllisyyttä ja koota kollektiivista muistia menneestä. Sekä DDR-museot että DDR Zonenkinder synnyttävät vaihtoehtoisia näkemyksiä DDR:n menneisyydestä, nämä ovat muussa keskustelussa ovat jääneet vähemmälle huomiolle. DDR:n kaaduttua 1989 ja vuotta myöhemmin Saksojen yhdistyttyä alkoi Saksassa kiivas keskustelu siitä, kuinka DDR:n menneisyyttä tulisi käsitellä. Saksa on toistaiseksi ainoa maa, jossa on yhden vuosisadan aikana järjestetty kaksi totuuskomissiota: ensimmäinen holokaustin ja toinen DDR:n kaatumisen jälkeen. Saksan kielessä on jopa kaksi sanaa, Vergangenheitsbeweltigung sekä Geschichtsaufarbeitung, jotka tarkoittavat menneisyyden käsittelyä tai sen työstämistä. Voi siis sanoa, että vaikean menneisyyden käsittely on saksalaisten erityisosaamista. Totuuskomissio, rajavartioiden oikeudenkäynnit, Stasin arkistojen läpikäyminen sekä DDR:n vertaaminen kolmanteen valtakuntaan saivat itäsaksalaiset tuntemaan itsensä toisen luokan kansalaisiksi, joilla ei ollut oikeutta omaan menneisyyteensä, mutta ei myöskään omaan tulevaisuuteensa. Itäsaksalaisista tuntui, ettei heidän elämänsä menneisyys näkynyt Länsi-Saksan hallinnoimassa historiankirjoituksessa. DDR:n nopea katoaminen niin poliittisena järjestelmänä kuin materiaalisena kulttuurina kiihdytti Ostalgien syntyä. Itäsaksalaisten vuosikymmeniä odottamat läntiset kulutushyödykkeet sekä vauraus ja hyvinvointi eivät saavuttaneetkaan itää siinä määrin ja yhtä nopeasti kuin siellä oli oletettu. Yhdistymisen aikaansaama euforia muuttui pian pettymykseksi, kun uuteen systeemin sopeutuminen ei onnistunut kivuttomasti. Analyysissa käytetään Daphne Berdahlin näkemystä Ostalgiesta keinona luoda vastanarratiiveja. Tämän lisäksi analyysissä tukeudutaan Paul Cooken näkemykseen Ostalgiesta Länsi-Saksan harjoittaman itäsaksalaisen kulttuurin ja historian kolonisaation vastustamisena. Tutkielmassa Ostalgie nähdään itäsaksalaisten vastarintana ja itsemääräämisoikeuden vaatimisena. Tutkielmassa tullaan myös siihen johtopäätökseen, että Ostalgiessa pohjimmiltaan kysymys on uuden järjestelmän ja länsimaisen kulttuurin hallitsemisesta ripauksella itäsaksalaista erityislaatuisuutta eikä niinkään menneisyyden haikailusta tai halusta palauttaa DDR valtiona tai poliittisena järjestelmänä. Ostalgien avulla itäsaksalaiset rakentavat uudenlaista identiteettiä uudessa systeemissä, mutta kuitenkin säilyttävät osan jotain vanhaa ja erityslaatuista.

A new classification and linear sequence of extant gymnosperms

A new classification and linear sequence of the gymnosperms based on previous molecular and morphological phylogenetic and other studies is presented. Currently accepted genera are listed for each family and arranged according to their (probable) phylogenetic position. A full synonymy is provided, and types are listed for accepted genera. An index to genera assists in easy access to synonymy and family placement of genera.

Verkkokauppaa politiikan mielikuvilla – blogit parlamentaarikkojen imagonrakennuksen työkaluina

Tutkielmassa tarkastellaan suomalaisten eturivin poliitikkojen blogiviestintää imagonrakennuksen näkökulmasta. Tarkoitus on selvittää, millä tavalla poliitikot käyttävät blogejaan osana imagonrakennusprosessia. Tutkimuskysymyksen taustalla on ajatus yhteiskunnan viestinnällistymisestä, ”medialisoitumisesta”. Mediavälineiden ja -sisältöjen kyllästämässä mielikuvayhteiskunnassa jokainen joutuu pitämään huolta siitä, millainen imago hänelle muiden mielissä muodostuu. Mielikuvayhteiskunnassa imagot kilpailevat toisiaan vastaan ideologioiden sijaan, ja poliitikot pyrkivät erottumaan toisistaan ja kauppaamaan itseään äänestäjille mielikuvien avulla. Koska poliitikot taustaryhmineen voivat kommunikoida yleisöille blogien avulla ilman perinteisten tiedotusvälineiden väliintuloa, blogien merkitys imagoiden rakentamisessa, muokkaamisessa ja ylläpitämisessä on huomionarvoinen. Tutkielma sijoittuu poliittisen viestinnän tutkimuksen kenttään ja siinä hyödynnetään myös retoriikan tutkimuksen perusteita. David Nimmon teoria jakaa imagoviestinnän kolmeen aspektiin: ajatteluun ja tulkintaan liittyvään kognitiiviseen puoleen, tunteisiin vetoavaan affektiiviseen osaan sekä konatiiviseen, eli toimintaan kehottavaan elementtiin. Ferdinand de Saussuren linjaamien semiotiikan käytäntöjen mukaan viestintä puolestaan koostuu semioottisista valinnoista. Blogeissa käytettyjen semioottisen valintojen perusteella imagoviestinnän eri aspektit korostuvat halutuilla tavoilla. Tutkielmassa tarkastellaan imagonrakennuksen näkökulmasta niitä retorisia keinoja ja valintoja, joita blogikirjoituksissa esiintyy. Tutkielman alkuperäislähteinä ovat 24:n näkyvässä asemassa olevan suomalaisen poliitikon blogit tai vastaavat verkkosivut syksyltä 2009 ja keväältä 2010. Mukaan valittiin kaikki sellaiset eduskuntapuolueiden sekä valiokuntien puheenjohtajat, jotka päivittivät sisältöä blogeihinsa säännöllisesti. Tutkielman tärkeimpiä kirjallisuuslähteitä ovat muiden muassa Erkki Karvosen, David Nimmon, Risto Uimosen sekä Pekka Isotaluksen teokset. Tutkielman metodologisena apuvälineenä on sovellettu laadullisen sisällönanalyysin menetelmiä kuten palautesilmukkaa. Palautesilmukan induktiivisessa vaiheessa aineiston pohjalta on ensin toistuvien lukukertojen myötä muodostettu kategoriat, joihin varsinaiset sisällöt on sitten deduktiivisessa vaiheessa lajiteltu lopullista analyysia varten. Näin on saatu esiin erilaisia imagotyyppejä, joihin poliitikot itsensä blogeissaan asemoivat sekä imagonrakennuskeinoja, joita he blogiviestinnässään käyttävät. Tutkimus osoittaa, että useimmat suomalaiset poliitikot pyrkivät rakentamaan imagojaan asiapitoisista lähtökohdista, riskittömästi ja hillitysti. Imagoviestit sisällytetään tiiviisti asia-aiheiden yhteyteen eikä imagotekijöitä tyrkytetä sisältöjen kustannuksella. Kognitiiviset elementit korostuvat affektiivisten kustannuksella. Vaikka provokatiivisia intohimopoliitikkojakin joukosta löytyy, suurin osa pyrkii profiloitumaan imagoltaan viileiksi ja osaaviksi asiantuntijoiksi.

Monologeista dialogiksi : Keskustelua koulusta käytävien ohipuhumisten muuttamisesta neuvotteluksi sosiaalisen konstruktionismin hengessä.

From monologues to dialogue. A discussion about changing the fragmented character of the debate concerning schools to one of negotiation, in the spirit of social constructionism. The starting point for the study is the assumption that the interested parties concerning schools such as teachers, students, public servants within school administration or politics construct the idea of the school in disparate ways. It looks as if the representatives of the various interested parties perceive the school in distinctive ways or with particular emphases. Additionally, there are not many discussion forums where these different interested parties have an equal right to speak and be heard. It seems that the lack of dialogue characterizes the debate about school. At the centre of the study are negotiations concerning schools, and the conditions that promote changing the fragmented character of this school debate in a more promising and collectively responsible process of negotiation. The aims of the study are to find both an empirical and theoretical basis for more equal ways to negotiate about school, and to increase cultural self reflection. Social constructionism plays a key role in aspiring to meet these research aims. The research questions are (1) How do the informants of the study construct the idea of school in their texts, and (2) What kind of prospects does social constructionism bring to the negotiations about school. The research informants construct the idea of school in their texts in several ways. To sum up: school is constructed as a place for learning, a place for building the future, a place where ethical education is lived out, a place for social education and Bildung, and a place where the students well-being is ensured. The previously presented assumption that the interested parties of a school construct the idea of a school in disparate ways or with various emphases seems to have support in the informants texts. Based on that, a condition can be put forward: different perspectives should have an equal opportunity to be heard in negotiations about school. It would also be helpful if there was a chance for different perspectives to be documented and/or in some way, visualized. This ensures that different constructions of school are within reach of all the participants. Additionally, while making the process of negotiation transparent, this documentation becomes an important medium for self reflection. On one hand it visualizes the complexity of the school. On the other hand it protects the school and education from serving as the spokesman of any single truth that is presented as objective or universal. Social constructionism seems to offer a stable theoretical basis for changing the fragmented character of the school debate in one of negotiation. More equal and collectively responsible school negotiation presumes that certain aspects or conditions drawn from postmodernism and social constructionism have been studied. In the study, six conditions are presented that can be seen as mediums for changing the fragmented character of the school debate into one of more equal negotiation. Keywords: social constructionism, Kenneth J. Gergen, school negotiation, education policy, dialogue.

Harvesting undelimbed Scots pine (Pinus sylvestris L.) from first thinnings for integrated production of kraft pulp and energy

The present study evaluates the feasibility of undelimbed Scots pine (Pinus sylvestris L.) for integrated production of pulp and energy in a kraft pulp mill from the technical, economic and environmental points of view, focusing on the potential of bundle harvesting. The feasibility of tree sections for pulp production was tested by conducting an industrial wood-handling experiment, laboratory cooking and bleaching trials, using conventional small-diameter Scots pine pulpwood as a reference. These trials showed that undelimbed Scots pine sections can be processed in favourable conditions as a blend with conventional small-diameter pulpwood without reducing the pulp quality. However, fibre losses at various phases of the process may increase when using undelimbed material. In the economic evaluation, both pulp production and wood procurement costs were considered, using the relative wood paying capability of a kraft pulp mill as a determinant. The calculations were made for three Scots pine first-thinning stands with the breast-height diameter of the removal (6 12 cm) as the main distinctive factor. The supply chains included in the comparison were based on cut-to-length harvesting, whole-tree harvesting and bundle harvesting (whole-tree bundling). With the current ratio of pulp and energy prices, the wood paying capability declines with an increase in the proportion of the energy fraction of the raw material. The supply system based on the cut-to-length method was the most efficient option, resulting in the highest residual value at stump in most cases. A decline in the pulp price and an increase in the energy price improved the competitiveness of the whole-tree systems. With short truck transportation distances and low pulp prices, however, the harvesting of loose whole trees can result in higher residual value at stump in small-diameter stands. While savings in transportation costs did not compensate for the high cutting and compaction costs by the second prototype of the bundle harvester, an increase in transportation distances improved its competitiveness. Since harvesting undelimbed assortments increases nutrient export from the site, which can affect soil productivity, the whole-tree alternatives included in the present study cannot be recommended on infertile peatlands and mineral soils. The harvesting of loose whole trees or bundled whole trees implies a reduction in protective logging residues and an increase in site traffic or payloads. These factors increase the risk of soil damage, especially on peat soils with poor bearing capacity. Within the wood procurement parameters which were examined, the CO2 emissions of the supply systems varied from 13 27 kg m3. Compaction of whole trees into bundles reduced emissions from transportation by 30 39%, but these reductions were insufficient to compensate for the increased emissions from cutting and compaction.

Laboratory studies on ball wear in the grinding of a hematite-magnetite ore

Marked-ball grinding tests were carried out under different grinding conditions and environments. Three types of balls were used, namely, cast hyper steel, high chrome cast iron and EN-31 (forged), which cover a wide range of chemical composition, microstructure and media hardness. The effect of pulp density on ball wear and grinding efficiency was also studied. Relative pulp viscosities at different percent solids for the ore slurry were also determined. As the Kudremukh ore contained about 0.2% pyrite, the effect of addition of pyrite on ball wear was studied separately. Results of marked-ball grinding tests indicated that ball wear increased with time and showed a sharp increase for wet grinding over dry grinding. Ball wear under wet grinding conditions was also influenced by the gaseous atmosphere in the mill. At 70% solids, the best results in terms of reduced ball wear coupled with satisfactory grinding efficiency were obtained. The influence of oxygen on the corrosive wear of grinding balls was increasingly felt only if sulphide minerals such as pyrite were also present in the ore. The various ball materials could be arranged in the following order with respect to their overall wear resistance: high chrome cast iron > EN-31 (forged) > cast hyper steel.Possible ball wear mechanisms involved in the grinding of Kudremukh ore are discussed.

A new approach to the kinetics of size reduction in ball milling

The rate of breakage of feed in ball milling is usually represented in the form of a first-order rate equation. The equation was developed by treating a simple batch test mill as a well mixed reactor. Several case of deviation from the rule have been reported in the literature. This is attributed to the fact that accumulated fines interfere with the feed material and breaking events are masked by these fines. In the present paper, a new rate equation is proposed which takes into account the retarding effect of fines during milling. For this purpose the analogy of diffusion of ions through permeable membranes is adopted, with suitable modifications. The validity of the model is cross checked with the data obtained in batch grinding of ?850/+600 ?m size quartz. The proposed equation enables calculation of the rate of breakage of the feed at any instant of time.

Ball wear and its control in the grinding of a lead-zinc sulphide ore

Marked ball grinding tests were carried out in the laboratory with a lead-zinc sulphide ore under different experimental conditions using high carbon low alloy steel (cast and forged) and high chrome cast iron balls. Relative ball wear as a function of grinding period and milling conditions was evaluated for the different types of ball materials. The role of corrosion and abrasion-erosion in the wear of grinding media is brought out. Methods to minimise ball wear through control of mill atmosphere and addition of reagents are discussed.

Hantavirus infection: Insights into entry, assembly and pathogenesis

Hantaviruses (family Bunyaviridae, genus Hantavirus) are enveloped viruses incorporating a segmented, negative-sense RNA genome. Each hantavirus is carried by its specific host, either a rodent or an insectivore (shrew), in which the infection is asymptomatic and persistent. In humans, hantaviruses cause Hemorrhagic fever with renal syndrome (HFRS) in Eurasia and Hantavirus cardiopulmonary syndrome (HCPS) in the Americas. In Finland, Puumala virus (genus Hantavirus) is the causative agent of NE, a mild form of HFRS. The HFRS-type diseases are often associated with renal failure and proteinuria that might be mechanistically explained by infected kidney tubular cell degeneration in patients. Previously, it has been shown that non-pathogenic hantavirus, Tula virus (TULV), could cause programmed cell death, apoptosis, in cell cultures. This suggested that the infected kidney tubular degeneration could be caused directly by virus replication. In the first paper of this thesis the molecular mechanisms involved in TULV-induced apoptosis was further elucidated. A virus replication-dependent down-regulation of ERK1/2, concomitantly with the induced apoptosis, was identified. In addition, this phenomenon was not restricted to TULV or to non-pathogenic hantaviruses in general since also a pathogenic hantavirus, Seoul virus, could inhibit ERK1/2 activity. Hantaviruses consist of membrane-spanning glycoproteins Gn and Gc, RNA-dependent RNA polymerase (L protein) and nucleocapsid protein N, which encapsidates the viral genome, and thus forms the ribonucleoprotein (RNP). Interaction between the cytoplasmic tails of viral glycoproteins and RNP is assumed to be the only means how viral genetic material is incorporated into infectious virions. In the second paper of this thesis, it was shown by immunoprecipitation that viral glycoproteins and RNP interact in the purified virions. It was further shown that peptides derived from the cytoplasmic tails (CTs) of both Gn and Gc could bind RNP and recombinant N protein. In the fourth paper the cytoplamic tail of Gn but not Gc was shown to interact with genomic RNA. This interaction was probably rather unspecific since binding of Gn-CT with unrelated RNA and even single-stranded DNA were also observed. However, since the RNP consists of both N protein and N protein-encapsidated genomic RNA, it is possible that the viral genome plays a role in packaging of RNPs into virions. On the other hand, the nucleic acid-binding activity of Gn may have importance in the synthesis of viral RNA. Binding sites of Gn-CT with N protein or nucleic acids were also determined by peptide arrays, and they were largely found to overlap. The Gn-CT of hantaviruses contain a conserved zinc finger (ZF) domain with an unknown function. Some viruses need ZFs in entry or post-entry steps of the viral life cycle. Cysteine residues are required for the folding of ZFs by coordinating zinc-ions, and alkylation of these residues can affect virus infectivity. In the third paper, it was shown that purified hantavirions could be inactivated by treatment with cysteine-alkylating reagents, especially N-ethyl maleimide. However, the effect could not be pin-pointed to the ZF of Gn-CT since also other viral proteins reacted with maleimides, and it was, therefore, impossible to exclude the possibility that other cysteines besides those that were essential in the formation of ZF are required for hantavirus infectivity.