Langattoman peltotiedustelijan maanalainen toimintaympäristö ja laitesuunnittelu

Tässä väitöskirjassa esitellään langattomien maanalaisten peltotiedustelijoiden järjestelmän tavoitteet ja rajoitukset. Tarkoitus oli kehittää käytännön viljelyyn sovellettava pellon seurantajärjestelmä, sillä reaaliaikaisen kosteus- ja lämpötilatiedon keruulaitteiden puuttuminen haittaa viljelytoimenpiteiden suunnittelua. Mittaus-aineistosta voi tehdä sekä havaintoja pellon ominaisuuksista että muutoksista niissä. Tulevaisuudessa tiedustelijalla saatetaan voida mitata ravinteita tai kemikaaleja. Kun peltotiedustelijan 869 MHz:n radioaalto saavuttaa vastaanottoantennin, on 1) maa-aines vaimentanut sitä; 2) osa aallosta heijastunut rajapinnoilta; 3) pellosta ulos taittuva aalto hajaantunut ja; 4) aallon intensiteetti alentunut etäisyyden kasvaessa. Maan sähkökenttäkäyttäytymistä kuvaava permittiivisyys on kompleksinen suure, jonka reaaliosa kuvaa varautumiskykyä (polarisoitumista) ja imaginaariosa häviöllisyyttä (sähkönjohtavuutta). Pellon pinnassa aalto on pallomainen, joten heijastumisen lisäksi hajaannuttaa taittuminen suurilla taitekulmilla sen tehoa. Tiedustelijan prototyyppiä varten kehitettiin maa-aineksessa toimivat antennit, joiden taajuuskaistat kattoivat ne aallonpituudet, jotka 869 MHz:n radioaalto saa kuivassa ja märässä mullassa, sillä aallon etenemisnopeus ja pituus muuttuvat maan kosteudesta riippuen. Vaimennusmallin testausmittauksiin tehtiin discone-antenni, ja tiedustelijaa varten piirilevytekniikalla pienikokoinen elliptinen monopoliantenni, jonka piirikortille ladottiin myös tiedustelijan elektroniikka. Multalaatikkoon upotettujen antennien säteilyominaisuudet määritettiin piirianalysaattorilla heijastusvaimennusmittauksin. Elektroniikkasuunnittelun tavoitteita oli pieni koko ja pitkä toimintaikä. Näihin päästiin komponenttivalinnoilla sekä ohjelmoinnin keinoin. Tiedustelija teki mittaukset ja lähetti tulokset 10 min välein ja sen keskivirrankulutus oli 4,2 uA käytettäessä 3 V:n paristoa, jonka 1800 mAh kapasiteetti riittäisi huonollakin hyötysuhteella yli 10 vuodeksi. Vuoden mittaisen 12 prototyypin käytön perusteella voidaan kantamaa parantaa yli nykyisen 200 m:n ilman käyttöiän lyhentymistä 1) nostamalla laitteen lähetystehoa ja pariston käyttöastetta lisäkomponenteilla; 2) parantamalla vastaanottoantennin vahvistusta; 3) pidentämällä lähetysten jaksoa; 4) ohjelmoimalla tiedustelija suodattamaan mittaustietoja ja; 5) koodaamalla useita tuloksia samaan lähetteeseen. Järjestelmän ja mittaustulosten käytettävyyttä voidaan parantaa paikantamalla tiedustelijoiden syvyydet aaltoilevan lämpötilan vaihe-erojen perusteella ja ohjelmoimalla tiedustelijaan opastava asennustoiminto. Lisäksi maahan asennetun tiedustelijan toimintaparametrit tai jopa koko ohjelmisto voidaan vaihtaa langattomasti. Vastaanottoasemat matkapuhelinmastoissa voisivat vastaanottaa viestejä parin kilometrin säteeltä. Koostettu aineisto maaperäsimulaattoreihin yhdistettynä antaisi kuvan alueellisesta tilanteesta ja viljelijän omille lohkoille sijoitetut tiedustelijat korjauspisteitä keskiarvosta.

Plant species diversity of buffer zones in agricultural landscapes: in search of determinants from the local to regional scale

Buffer zones are vegetated strip-edges of agricultural fields along watercourses. As linear habitats in agricultural ecosystems, buffer strips dominate and play a leading ecological role in many areas. This thesis focuses on the plant species diversity of the buffer zones in a Finnish agricultural landscape. The main objective of the present study is to identify the determinants of floral species diversity in arable buffer zones from local to regional levels. This study was conducted in a watershed area of a farmland landscape of southern Finland. The study area, Lepsämänjoki, is situated in the Nurmijärvi commune 30 km to the north of Helsinki, Finland. The biotope mosaics were mapped in GIS. A total of 59 buffer zones were surveyed, of which 29 buffer strips surveyed were also sampled by plot. Firstly, two diversity components (species richness and evenness) were investigated to determine whether the relationship between the two is equal and predictable. I found no correlation between species richness and evenness. The relationship between richness and evenness is unpredictable in a small-scale human-shaped ecosystem. Ordination and correlation analyses show that richness and evenness may result from different ecological processes, and thus should be considered separately. Species richness correlated negatively with phosphorus content, and species evenness correlated negatively with the ratio of organic carbon to total nitrogen in soil. The lack of a consistent pattern in the relationship between these two components may be due to site-specific variation in resource utilization by plant species. Within-habitat configuration (width, length, and area) were investigated to determine which is more effective for predicting species richness. More species per unit area increment could be obtained from widening the buffer strip than from lengthening it. The width of the strips is an effective determinant of plant species richness. The increase in species diversity with an increase in the width of buffer strips may be due to cross-sectional habitat gradients within the linear patches. This result can serve as a reference for policy makers, and has application value in agricultural management. In the framework of metacommunity theory, I found that both mass effect(connectivity) and species sorting (resource heterogeneity) were likely to explain species composition and diversity on a local and regional scale. The local and regional processes were interactively dominated by the degree to which dispersal perturbs local communities. In the lowly and intermediately connected regions, species sorting was of primary importance to explain species diversity, while the mass effect surpassed species sorting in the highly connected region. Increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities, and consequently, to lower regional diversity, while local species richness was unrelated to the habitat connectivity. Of all species found, Anthriscus sylvestris, Phalaris arundinacea, and Phleum pretense significantly responded to connectivity, and showed high abundance in the highly connected region. We suggest that these species may play a role in switching the force from local resources to regional connectivity shaping the community structure. On the landscape context level, the different responses of local species richness and evenness to landscape context were investigated. Seven landscape structural parameters served to indicate landscape context on five scales. On all scales but the smallest scales, the Shannon-Wiener diversity of land covers (H') correlated positively with the local richness. The factor (H') showed the highest correlation coefficients in species richness on the second largest scale. The edge density of arable field was the only predictor that correlated with species evenness on all scales, which showed the highest predictive power on the second smallest scale. The different predictive power of the factors on different scales showed a scaledependent relationship between the landscape context and local plant species diversity, and indicated that different ecological processes determine species richness and evenness. The local richness of species depends on a regional process on large scales, which may relate to the regional species pool, while species evenness depends on a fine- or coarse-grained farming system, which may relate to the patch quality of the habitats of field edges near the buffer strips. My results suggested some guidelines of species diversity conservation in the agricultural ecosystem. To maintain a high level of species diversity in the strips, a high level of phosphorus in strip soil should be avoided. Widening the strips is the most effective mean to improve species richness. Habitat connectivity is not always favorable to species diversity because increasing connectivity in communities containing high habitat heterogeneity can lead to the homogenization of local communities (beta diversity) and, consequently, to lower regional diversity. Overall, a synthesis of local and regional factors emerged as the model that best explain variations in plant species diversity. The studies also suggest that the effects of determinants on species diversity have a complex relationship with scale.

Effect of fire and tree-grass patches on soil nitrogen in Australian tropical savannas

Fire is an important driver of nutrient cycling in savannas. Here, we determined the impact of fire frequency on total and soluble soil nitrogen (N) pools in tropical savanna. The study sites consisted of 1-ha experimental plots near Darwin, Australia, which remained unburnt for at least 14 years or were burnt at 1-, 2- or 5-year intervals over the past 6 years. Soil was analysed from patches underneath tree canopies and in inter-canopy patches at 1, 12, 28, 55 and 152 days after fire. Patch type had a significant effect on all soil N pools, with greater concentrations of total and soluble (nitrate, ammonium, amino acids) N under tree canopies than inter-canopy patches. The time since the last fire had no significant effect on N pools. Fire frequency similarly did not affect total soil N but it did influence soluble soil N. Soil amino acids were most prominent in burnt savanna, ammonium was highest in infrequently burnt (5-year interval) savanna and nitrate was highest in unburnt savanna. We suggest that the main effect of fire on soil N relations occurs indirectly through altered tree-grass dynamics. Previous studies have shown that high fire frequencies reduce tree cover by lowering recruitment and increasing mortality. Our findings suggest that these changes in tree cover could result in a 30% reduction in total soil N and 1060% reductions in soluble N pools. This finding is consistent with studies from savannas globally, providing further evidence for a general theory of patchiness as a key driver of nutrient cycling in the savanna biome.

Movement-associated proteins of Potato virus A: attachment to virus particles and phosphorylation

The particles of Potato virus A (PVA; genus Potyvirus) are helically constructed filaments that contain multiple copies of a single type of coat-protein (CP) subunit and a single copy of genome-linked protein (VPg), attached to one end of the virion. Examination of negatively-stained virions by electron microscopy revealed flexuous, rod-shaped particles with no obvious terminal structures. It is known that particles of several filamentous plant viruses incorporate additional minor protein components, forming stable complexes that mediate particle disassembly, movement or transmission by insect vectors. The first objective of this work was to study the interaction of PVA movement-associated proteins with virus particles and how these interactions contribute to the morphology and function of the virus particles. Purified particles of PVA were examined by atomic force microscopy (AFM) and immuno-gold electron microscopy. A protrusion was found at one end of some of the potyvirus particles, associated with the 5' end of the viral RNA. The tip contained two virus-encoded proteins, the genome-linked protein (VPg) and the helper-component proteinase (HC-Pro). Both are required for cell-to-cell movement of the virus. Biochemical and electron microscopy studies of purified PVA samples also revealed the presence of another protein required for cell-to-cell movement the cylindrical inclusion protein (CI), which is also an RNA helicase/ATPase. Centrifugation through a 5-40% sucrose gradient separated virus particles with no detectable CI to a fraction that remained in the gradient, from the CI-associated particles that went to the pellet. Both types of particles were infectious. AFM and translation experiments demonstrated that when the viral CI was not present in the sample, PVA virions had a beads-on-a-string phenotype, and RNA within the virus particles was more accessible to translation. The second objective of this work was to study phosphorylation of PVA movement-associated and structural proteins (CP and VPg) in vitro and, if possible, in vivo. PVA virion structural protein CP is necessary for virus cell-to-cell movement. The tobacco protein kinase CK2 was identified as a kinase phosphorylating PVA CP. A major site of CK2 phosphorylation in PVA CP was identified as a single threonine within a CK2 consensus sequence. Amino acid substitutions affecting the CK2 consensus sequence in CP resulted in viruses that were defective in cell-to-cell and long-distance movement. The CK2 regulation of virion assembly and cell-to-cell movement by phosphorylation of CP was possibly due to the inhibition of CP binding to viral RNA. Four putative phosphorylation sites were identified from an in vitro phosphorylated recombinant VPg. All four were mutated and the spread of mutant viruses in two different host plants was studied. Two putative phosphorylation site mutants (Thr45 and Thr49) had phenotypes identical to that of a wild type (WT) virus infection in both Nicotiana benthamiana and N. tabacum plants. The other two mutant viruses (Thr132/Ser133 and Thr168) showed different phenotypes with increased or decreased accumulation rates, respectively, in inoculated and the first two systemically infected leaves of N. benthamiana. The same mutants were occasionally restricted to single cells in N. tabacum plants, suggesting the importance of these amino acids in the PVA infection cycle in N. tabacum.

Lost in Translation : Translation Mechanisms in Production of Cocksfoot Mottle Virus Proteins

The present study focuses on the translational strategies of Cocksfoot mottle virus (CfMV, genus Sobemovirus), which infects monocotyledonous plants. CfMV RNA lacks the 5'cap and the 3'poly(A) tail that ensure efficient translation of cellular messenger RNAs (mRNAs). Instead, CfMV RNA is covalently linked to a viral protein VPg (viral protein, genome-linked). This indicates that the viral untranslated regions (UTRs) must functionally compensate for the lack of the cap and poly(A) tail. We examined the efficacy of translation initiation in CfMV by comparing it to well-studied viral translational enhancers. Although insertion of the CfMV 5'UTR (CfMVe) into plant expression vectors improved gene expression in barley more than the other translational enhancers examined, studies at the RNA level showed that CfMVe alone or in combination with the CfMV 3'UTR did not provide the RNAs translational advantage. Mutation analysis revealed that translation initiation from CfMVe involved scanning. Interestingly, CfMVe also promoted translation initiation from an intercistronic position of dicistronic mRNAs in vitro. Furthermore, internal initiation occurred with similar efficacy in translation lysates that had reduced concentrations of eukaryotic initiation factor (eIF) 4E, suggesting that initiation was independent of the eIF4E. In contrast, reduced translation in the eIF4G-depleted lysates indicated that translation from internally positioned CfMVe was eIF4G-dependent. After successful translation initiation, leaky scanning brings the ribosomes to the second open reading frame (ORF). The CfMV polyprotein is produced from this and the following overlapping ORF via programmed -1 ribosomal frameshift (-1 PRF). Two signals in the mRNA at the beginning of the overlap program approximately every fifth ribosome to slip one nucleotide backwards and continue translation in the new -1 frame. This leads to the production of C-terminally extended polyprotein, which encodes the viral RNA-dependent RNA polymerase (RdRp). The -1 PRF event in CfMV was very efficient, even though it was programmed by a simple stem-loop structure instead of a pseudoknot, which is usually required for high -1 PRF frequencies. Interestingly, regions surrounding the -1 PRF signals improved the -1 PRF frequencies. Viral protein P27 inhibited the -1 PRF event in vivo, putatively by binding to the -1 PRF site. This suggested that P27 could regulate the occurrence of -1 PRF. Initiation of viral replication requires that viral proteins are released from the polyprotein. This is catalyzed by viral serine protease, which is also encoded from the polyprotein. N-terminal amino acid sequencing of CfMV VPg revealed that the junction of the protease and VPg was cleaved between glutamate (E) and asparagine (N) residues. This suggested that the processing sites used in CfMV differ from the glutamate and serine (S) or threonine (T) sites utilized in other sobemoviruses. However, further analysis revealed that the E/S and E/T sites may be used to cleave out some of the CfMV proteins.

In vitro culture of the allergenic weed Parthenium hysterophorus L

Excised stem, leaf segments and whole flower of the allergenic weed P. hysterophorus were cultured on Murashighe and Skoog's basal medium supplemented with hormones. Shoot buds readily formed in the stem callus cultured on MS Medium supplemented with IAA and BAP or Kinetin. The leaf callus formed roots alone in a wide variety of media. Suspension cultures were initiated from the leaf and stem callus. The leaf callus elicited a positive patch test response for delayed hypersensitivity in 4 patients suffering from Parthenium dermatitis, thus indicating its ability to synthesise the allergenic principle(s).

Stiffer Optical Tweezers through Real-Time Feedback Control

This thesis integrates real-time feedback control into an optical tweezers instrument. The goal is to reduce the variance in the trapped bead s position, -effectively increasing the trap stiffness of the optical tweezers. Trap steering is done with acousto-optic deflectors and control algorithms are implemented with a field-programmable gate array card. When position clamp feedback control is on, the effective trap stiffness increases 12.1-times compared to the stiffness without control. This allows improved spatial control over trapped particles without increasing the trapping laser power.

Sustainable grazing management for temporal and spatial variability in north Australian rangelands – a synthesis of the latest evidence and recommendations

Rainfall variability is a major challenge to sustainable grazing management in northern Australia, with management often complicated further by large, spatially-heterogeneous paddocks. This paper presents the latest grazing research and associated bio-economic modelling from northern Australia and assesses the extent to which current recommendations to manage for these issues are supported. Overall, stocking around the safe long-term carrying capacity will maintain land condition and maximise long-term profitability. However, stocking rates should be varied in a risk-averse manner as pasture availability varies between years. Periodic wet-season spelling is also essential to maintain pasture condition and allow recovery of overgrazed areas. Uneven grazing distributions can be partially managed through fencing, providing additional water-points and in some cases patch-burning, although the economics of infrastructure development are extremely context-dependent. Overall, complex multi-paddock grazing systems do not appear justified in northern Australia. Provided the key management principles outlined above are applied in an active, adaptive manner, acceptable economic and environmental outcomes will be achieved irrespective of the grazing system applied.

Topographical, structural and geophysical characterization of fracture zones: implications for groundwater flow and vulnerability

The main objective of this study is to evaluate selected geophysical, structural and topographic methods on regional, local, and tunnel and borehole scales, as indicators of the properties of fracture zones or fractures relevant to groundwater flow. Such information serves, for example, groundwater exploration and prediction of the risk of groundwater inflow in underground construction. This study aims to address how the features detected by these methods link to groundwater flow in qualitative and semi-quantitative terms and how well the methods reveal properties of fracturing affecting groundwater flow in the studied sites. The investigated areas are: (1) the Päijänne Tunnel for water-conveyance whose study serves as a verification of structures identified on regional and local scales; (2) the Oitti fuel spill site, to telescope across scales and compare geometries of structural assessment; and (3) Leppävirta, where fracturing and hydrogeological environment have been studied on the scale of a drilled well. The methods applied in this study include: the interpretation of lineaments from topographic data and their comparison with aeromagnetic data; the analysis of geological structures mapped in the Päijänne Tunnel; borehole video surveying; groundwater inflow measurements; groundwater level observations; and information on the tunnel s deterioration as demonstrated by block falls. The study combined geological and geotechnical information on relevant factors governing groundwater inflow into a tunnel and indicators of fracturing, as well as environmental datasets as overlays for spatial analysis using GIS. Geophysical borehole logging and fluid logging were used in Leppävirta to compare the responses of different methods to fracturing and other geological features on the scale of a drilled well. Results from some of the geophysical measurements of boreholes were affected by the large diameter (gamma radiation) or uneven surface (caliper) of these structures. However, different anomalies indicating more fractured upper part of the bedrock traversed by well HN4 in Leppävirta suggest that several methods can be used for detecting fracturing. Fracture trends appear to align similarly on different scales in the zone of the Päijänne Tunnel. For example, similarities of patterns were found between the regional magnetic trends, correlating with orientations of topographic lineaments interpreted as expressions of fracture zones. The same structural orientations as those of the larger structures on local or regional scales were observed in the tunnel, even though a match could not be made in every case. The size and orientation of the observation space (patch of terrain at the surface, tunnel section, or borehole), the characterization method, with its typical sensitivity, and the characteristics of the location, influence the identification of the fracture pattern. Through due consideration of the influence of the sampling geometry and by utilizing complementary fracture characterization methods in tandem, some of the complexities of the relationship between fracturing and groundwater flow can be addressed. The flow connections demonstrated by the response of the groundwater level in monitoring wells to pressure decrease in the tunnel and the transport of MTBE through fractures in bedrock in Oitti, highlight the importance of protecting the tunnel water from a risk of contamination. In general, the largest values of drawdown occurred in monitoring wells closest to the tunnel and/or close to the topographically interpreted fracture zones. It seems that, to some degree, the rate of inflow shows a positive correlation with the level of reinforcement, as both are connected with the fracturing in the bedrock. The following geological features increased the vulnerability of tunnel sections to pollution, especially when several factors affected the same locations: (1) fractured bedrock, particularly with associated groundwater inflow; (2) thin or permeable overburden above fractured rock; (3) a hydraulically conductive layer underneath the surface soil; and (4) a relatively thin bedrock roof above the tunnel. The observed anisotropy of the geological media should ideally be taken into account in the assessment of vulnerability of tunnel sections and eventually for directing protective measures.

Geospatial environmental data modelling applications using remote sensing, GIS and spatial statistics

This thesis presents novel modelling applications for environmental geospatial data using remote sensing, GIS and statistical modelling techniques. The studied themes can be classified into four main themes: (i) to develop advanced geospatial databases. Paper (I) demonstrates the creation of a geospatial database for the Glanville fritillary butterfly (Melitaea cinxia) in the Åland Islands, south-western Finland; (ii) to analyse species diversity and distribution using GIS techniques. Paper (II) presents a diversity and geographical distribution analysis for Scopulini moths at a world-wide scale; (iii) to study spatiotemporal forest cover change. Paper (III) presents a study of exotic and indigenous tree cover change detection in Taita Hills Kenya using airborne imagery and GIS analysis techniques; (iv) to explore predictive modelling techniques using geospatial data. In Paper (IV) human population occurrence and abundance in the Taita Hills highlands was predicted using the generalized additive modelling (GAM) technique. Paper (V) presents techniques to enhance fire prediction and burned area estimation at a regional scale in East Caprivi Namibia. Paper (VI) compares eight state-of-the-art predictive modelling methods to improve fire prediction, burned area estimation and fire risk mapping in East Caprivi Namibia. The results in Paper (I) showed that geospatial data can be managed effectively using advanced relational database management systems. Metapopulation data for Melitaea cinxia butterfly was successfully combined with GPS-delimited habitat patch information and climatic data. Using the geospatial database, spatial analyses were successfully conducted at habitat patch level or at more coarse analysis scales. Moreover, this study showed it appears evident that at a large-scale spatially correlated weather conditions are one of the primary causes of spatially correlated changes in Melitaea cinxia population sizes. In Paper (II) spatiotemporal characteristics of Socupulini moths description, diversity and distribution were analysed at a world-wide scale and for the first time GIS techniques were used for Scopulini moth geographical distribution analysis. This study revealed that Scopulini moths have a cosmopolitan distribution. The majority of the species have been described from the low latitudes, sub-Saharan Africa being the hot spot of species diversity. However, the taxonomical effort has been uneven among biogeographical regions. Paper III showed that forest cover change can be analysed in great detail using modern airborne imagery techniques and historical aerial photographs. However, when spatiotemporal forest cover change is studied care has to be taken in co-registration and image interpretation when historical black and white aerial photography is used. In Paper (IV) human population distribution and abundance could be modelled with fairly good results using geospatial predictors and non-Gaussian predictive modelling techniques. Moreover, land cover layer is not necessary needed as a predictor because first and second-order image texture measurements derived from satellite imagery had more power to explain the variation in dwelling unit occurrence and abundance. Paper V showed that generalized linear model (GLM) is a suitable technique for fire occurrence prediction and for burned area estimation. GLM based burned area estimations were found to be more superior than the existing MODIS burned area product (MCD45A1). However, spatial autocorrelation of fires has to be taken into account when using the GLM technique for fire occurrence prediction. Paper VI showed that novel statistical predictive modelling techniques can be used to improve fire prediction, burned area estimation and fire risk mapping at a regional scale. However, some noticeable variation between different predictive modelling techniques for fire occurrence prediction and burned area estimation existed.

Single network adaptive critic design for power system stabilisers

The recently developed single network adaptive critic (SNAC) design has been used in this study to design a power system stabiliser (PSS) for enhancing the small-signal stability of power systems over a wide range of operating conditions. PSS design is formulated as a discrete non-linear quadratic regulator problem. SNAC is then used to solve the resulting discrete-time optimal control problem. SNAC uses only a single critic neural network instead of the action-critic dual network architecture of typical adaptive critic designs. SNAC eliminates the iterative training loops between the action and critic networks and greatly simplifies the training procedure. The performance of the proposed PSS has been tested on a single machine infinite bus test system for various system and loading conditions. The proposed stabiliser, which is relatively easier to synthesise, consistently outperformed stabilisers based on conventional lead-lag and linear quadratic regulator designs.

Individuals on the Move : Body Condition Dependent Dispersal and Quasi-Local Competition in Metapopulations

Individual movement is very versatile and inevitable in ecology. In this thesis, I investigate two kinds of movement body condition dependent dispersal and small-range foraging movements resulting in quasi-local competition and their causes and consequences on the individual, population and metapopulation level. Body condition dependent dispersal is a widely evident but barely understood phenomenon. In nature, diverse relationships between body condition and dispersal are observed. I develop the first models that study the evolution of dispersal strategies that depend on individual body condition. In a patchy environment where patches differ in environmental conditions, individuals born in rich (e.g. nutritious) patches are on average stronger than their conspecifics that are born in poorer patches. Body condition (strength) determines competitive ability such that stronger individuals win competition with higher probability than weak individuals. Individuals compete for patches such that kin competition selects for dispersal. I determine the evolutionarily stable strategy (ESS) for different ecological scenarios. My models offer explanations for both dispersal of strong individuals and dispersal of weak individuals. Moreover, I find that within-family dispersal behaviour is not always reflected on the population level. This supports the fact that no consistent pattern is detected in data on body condition dependent dispersal. It also encourages the refining of empirical investigations. Quasi-local competition defines interactions between adjacent populations where one population negatively affects the growth of the other population. I model a metapopulation in a homogeneous environment where adults of different subpopulations compete for resources by spending part of their foraging time in the neighbouring patches, while their juveniles only feed on the resource in their natal patch. I show that spatial patterns (different population densities in the patches) are stable only if one age class depletes the resource very much but mainly the other age group depends on it.

Kohtaamisia Santiagon tiellä pyhiinvaellus matkana ja spirituaalisena kokemuksena

Pyhiinvaellustutkimuksen tavoitteena on kuvata, analysoida ja ymmärtää pyhiinvaeltajien kokemuksia ja erityisesti spirituaalisia tai sellaisiksi tulkittuja kokemuksia. Tutkimuskysymys voidaan muotoilla myös kysymällä, missä on vaeltajien mahdollisesti kokema pyhiinvaelluksen pyhä . Pyhiinvaellus suuntautuu Santiago de Compostelan kaupunkiin. Kuvattu pyhiinvaellusreitti alkaa Ranskan ja Espanjan rajalta ja kulkee Espanjan luoteiskulmassa noin 800 kilometrin päässä olevaan määränpäähän. Tutkimuksen aineistona on sähköpostikyselyn vastaukset, jotka on saatu kahdeltakymmeneltäkahdelta keväällä 2006 Santiagoon jalkaisin vaeltaneilta pyhiinvaeltajilta. Tutkimusaineistona ovat myös tutkijan omat havainnot ko. pyhiinvaellukselta. Tutkijan havainnoista on kirjoitettu kuvaus Santiagon tien pyhiinvaelluksesta ja matkan arkisista käytännöistä. Sähköpostikyselyn vastaukset, vaeltajien spirituaaliset kokemukset, on analysoitu laadullista sisällön analysointia käyttäen. Kuudesta vastauksesta on kirjoitettu myös pyhiinvaeltajan henkilökohtainen tarina. Narratiivisuus, kerronnallisuus, on tässä tutkimuksessa yksi tapa esittää, kuvata ja ymmärtää tutkimustuloksia. Tutkimus on liitetty fenomenologiseen viitekehykseen. Spirituaalisia kokemuksia on lähestytty mm. pyhiinvaellustradition, pyhän käsitteen ja uskonnollisten kokemusten näkökulmasta. Spiritualiteetin käsitettä ja spirituaalisen kokemuksen kuvaamisen mahdollisuuksia on myös pohdittu tutkimuksessa. Pyhiinvaelluksen spirituaaliset kokemukset on tutkimusraportissa jaoteltu seitsemään ryhmään: kävely, ihmiset, vapaus, luonto, rukous, kirkot ja Santiago. Lisäksi on esitetty matkaan lähdön motiiveja sekä pyhiinvaelluksen vaikutuksia elämässä. Käveleminen oli pyhiinvaelluksen ydinkokemus. Käveleminen mahdollisti meditaation tai rukoilemisen. Se aiheutti myös kärsimystä ja oli keskeinen ihmisiä yhdistävä teema. Pyhiinvaellus irrotti ihmiset erittäin hyvin arjen rutiineista ja jokapäiväisestä normaalista elämästä. Pyhiinvaelluksella vapauden tunne olikin merkittävä spirituaalinen kokemus ja ajan käsitys saattoi saa uuden ulottuvuuden. Luonto näyttäytyi merkittävänä spirituaalisen innoituksen lähteenä ja usein myös yksinolon paikkana. Kaikki pyhiinvaeltajat vierailivat kirkoissa ja katedraaleissa ja useimmat myös messuissa ja pyhiinvaeltajille järjestetyissä rukoushetkissä. Pyhiinvaelluksen uskonnollinen ulottuvuus oli kaikille läsnä myös Santiagon messussa. Kristillinen tulkintakehys kokemuksille oli koko ajan pyhiinvaeltajalle tarjolla. Kuitenkaan Santiagon vaellukseen ei välttämättä liittynyt mitään omaa spirituaalista kokemusta. Pyhiinvaelluksen merkittävät spirituaaliset kokemukset liittyivät yhteisöllisyyteen ja jaettuihin kokemuksiin. Tyypillinen moderni pyhiinvaeltaja etsi itseään pyhiinvaelluksella. Yllätyksekseen hän saattoi löytää jotain silloin kun hän antautui avoimeen vuorovaikutukseen toisten ihmisten kanssa. Lähes kaikki tutkimuksen osallistuneet pyhiinvaeltajat pitivät hyvin tärkeänä toisia pyhiinvaeltajia ja sitä, mitä he saivat toisilta ihmisiltä. Pyhiinvaellusta leimaa poikkeuksellisen avoin vuorovaikutus ja elämän jakaminen. Pyhiinvaellukseen liittyy monia individualistisia piirteitä. Spirituaalisten kokemusten näkökulmasta individualismi ei kuitenkaan saa tukea tutkimuksesta, koska yhteisöllisyys näyttää niin merkittävältä spirituaalisten kokemusten kannalta. Pyhiinvaelluksen yhteisöllisyys on avointa, vapaaehtoista ja usein myös hetkellistä. Moderni pyhiinvaeltaja näyttää uskovan enemmän omiin kokemuksiinsa ja myös toisten kokemuksiin kuin minkään kirkon opilliseen auktoriteettiin.

Endoplasmic reticulum stress and cell death mechanisms in the cell model of Huntington’s disease

This thesis clarifies important molecular pathways that are activated during the cell death observed in Huntington’s disease. Huntington’s disease is one of the most common inherited neurodegenerative diseases, which is primarily inherited in an autosomal dominant manner. HD is caused by an expansion of CAG repeats in the first exon of the IT15 gene. IT15 encodes the production of a Huntington’s disease protein huntingtin. Mutation of the IT15 gene results in a long stretch of polyQ residues close to the amino-terminal region of huntingtin. Huntington’s disease is a fatal autosomal neurodegenerative disorder. Despite the current knowledge of HD, the precise mechanism behind the selective neuronal death, and how the disease propagates, still remains an enigma. The studies mainly focused on the control of endoplasmic reticulum (ER) stress triggered by the mutant huntingtin proteins. The ER is a delicate organelle having essential roles in protein folding and calcium regulation. Even the slightest perturbations on ER homeostasis are effective enough to trigger ER stress and its adaptation pathways, called unfolded protein response (UPR). UPR is essential for cellular homeostasis and it adapts ER to the changing environment and decreases ER stress. If adaptation processes fail and stress is excessive and prolonged; irreversible cell death pathways are engaged. The results showed that inhibition of ER stress with chemical agents are able to decrease cell death and formation of toxic cell aggregates caused by mutant huntingtin proteins. The study concentrated also to the NF-κB (nuclear factor-kappaB) pathway, which is activated during ER stress. NF-κB pathway is capable to regulate the levels of important cellular antioxidants. Cellular antioxidants provide a first line of defence against excess reactive oxygen species. Excess accumulation of reactive oxygen species and subsequent activation of oxidative stress damages motley of vital cellular processes and induce cell degeneration. Data showed that mutant huntingtin proteins downregulate the expression levels of NF-κB and vital antioxidants, which was followed by increased oxidative stress and cell death. Treatment with antioxidants and inhibition of oxidative stress were able to counteract these adverse effects. In addition, thesis connects ER stress caused by mutant huntingtin to the cytoprotective autophagy. Autophagy sustains cellular balance by degrading potentially toxic cell proteins and components observed in Huntington’s disease. The results revealed that cytoprotective autophagy is active at the early points (24h) of ER stress after expression of mutant huntingtin proteins. GADD34 (growth arrest and DNA damage-inducible gene 34), which is previously connected to the regulation of translation during cell stress, was shown to control the stimulation of autophagy. However, GADD34 and autophagy were downregulated at later time points (48h) during mutant huntingtin proteins induced ER stress, and subsequently cell survival decreased. Overexpression GADD34 enhanced autophagy and decreased cell death, indicating that GADD34 plays a critical role in cell protection. The thesis reveales new interesting data about the neuronal cell death pathways seen in Huntington’s disease, and how cell degeneration is partly counteracted by various therapeutic agents. Expression of mutant huntingtin proteins is shown to alter signaling events that control ER stress, oxidative stress and autophagy. Despite that Huntington’s disease is mainly an untreatable disorder; these findings offer potential targets and neuroprotective strategies in designing novel therapies for Huntington’s disease.

Short-term effects of variable retention on epigaeic spiders and carabid beetles in Finland

Forestry has influenced forest dwelling organisms for centuries in Fennoscandia. For example, in Finland ca. 30% of the threatened species are threatened because of forestry. Nowadays forest management recommendations include practices aimed at maintaining biodiversity in harvesting, such as green-tree retention. However, the effects of these practices have been little studied. In variable retention, different numbers of trees are retained, varying from green-tree retention (at least a few live standing trees in clear-cuts) to thinning (only individual trees removed). I examined the responses of ground-dwelling spiders and carabid beetles to green-tree retention (with small and large tree groups), gap felling and thinning aimed at an uneven age structure of trees. The impacts of these harvesting methods were compared to those of clear-cutting and uncut controls. I aimed to test the hypothesis that retaining more trees positively affects populations of those species of spiders and carabids that were present before harvesting. The data come from two studies. First, spiders were collected with pitfall traps in south-central Finland in 1995 (pre-treatment) and 1998 (after-treatment) in order to examine the effects of clear-cutting, green-tree retention (with 0.01-0.02-ha sized tree groups), gap felling (with three 0.16-ha sized openings in a 1-ha stand), thinning aiming at an uneven age structure of trees and uncut control. Second, spiders and carabids were caught with pitfall traps in eastern Finland in 1998-2001 (pre-treatment and three post-treatment years) in eleven 0.09-0.55-ha sized retention-tree groups and clear-cuts adjacent to them. Original spider and carabid assemblages were better maintained after harvests that retained more trees. Thinning maintained forest spiders well. However, gap felling and large retention-tree groups maintained some forest spider and carabid species in the short-term, but negatively affected some species over time. However, use of small retention-tree groups was associated with negative effects on forest spider populations. Studies are needed on the long-term effects of variable retention on terrestrial invertebrates; especially those directed at defining appropriate retention patch size and on the importance of structural diversity provided by variable retention for invertebrate populations. However, the aims of variable retention should be specified first. For example, are retention-tree groups planned to constitute life-boats , stepping-stones or to create structural diversity? Does it suffice that some species are maintained, or do we want to preserve the most sensitive ones, and how are these best defined? Moreover, the ecological benefits and economic costs of modified logging methods should be compared to other approaches aimed at maintaining biodiversity.