Diss. (sammanfattning) Alnarp : Sveriges lantbruksuniv., 2001. / Härtill 5 uppsatser.

The aim of this study was to examine age-related differences in decision-making competence. The study is a part of the ongoing Betula project (Nilsson et al., 1997; 2004), and the data included test results from (N, 364) corresponding to the questionnaires with complete responses (>80%) to the items addressed. The Swedish version of the Adult Decision-Making Competence (A-DMC) battery was used. An exploratory factor analysis of the A-DMC data yielded a two-component solution: The A-DMC tasks were divided into Factor 1 (Applying Decision Rules, Resistance to Framing and Consistency in Risk Perception tasks), and Factor 2 (Under/Overconfidence, Resistance to Sunk Costs and Recognizing Social Norms). These two factors showed opposite age effects, where Factor 1 (analytic decision making) declined with age, whereas Factor 2 (heuristic decision competence) was not negatively affected by old age. / Betula Project

No description available.

Blood pressure has previously been associated with decline in memory over time, though the exact mechanism behind this effect is uncertain. Infections, which can lead to systemic inflammation have also been linked to some cardiovascular damage to the brain, known as microbleeds, which have themselves been linked to greater declines in cognition in old age. The present study investigates whether blood pressure, a self-reported history of infection, and an indirect measure of inflammation known as the erythrocyte sedimentation rate have any association with on episodic and semantic memory and visuospatial skills in the Betula study, a Swedish longitudinal population study. The effect of elevated blood pressure (over 140 mm Hg systolic and/or 90 mm Hg diastolic), high blood sedimentation (top 33% against bottom 33% of participants), and self-reported infection were all found to not have any significant effect on episodic memory, semantic memory or visuospatial skills. Some of the possible explanations are elaborated in the discussion. / Högt blodtryck har associerats med minnesnedsättning men den exakta mekanismen hur ett samband kan förstås är dock oklar. Infektioner har visat sig ge systematiska inflammationer och har också satts i samband med vissa kardiovaskulära förändringar i hjärnan, så kallade mikroblödningar, vilka i sig har associerats med ökad risk för kognitive nedsättning i hög ålder. Denna uppsats syftar till att undersöka om blodtryck och infektion (självrapporterad infektion samt infektion indirekt mätt genom sänkereaktion) kan relateras till episodiskt och semantisk minne samt visuospatial förmåga i Betula studien, som är en svensk longitudinell populationsbaserad studie. Resultatet visade att varken högt blodtryck (över 140 mm Hg systoliskt eller 90 mm Hg diastoliskt), hög sänkereaktion (de 33 % med högst värde jämfört med de 33 % med lägst värde) eller självrapporterad infektion hade någon signifikant effekt för episodiskt minne, semantiskt minne eller visuospatial förmåga. Några möjliga förklaringar till detta resultat utvecklas i diskussionen. / The Betula Study

Fysisk aktivitet ger flertalet positiva fysiologiska hälsoeffekter och har vid ett antal studier även visat sig bidra till positiva hälsoeffekter avseende psykisk hälsa. Det finns dock studier som inte kunnat påvisa effekterna på psykisk hälsa. Syftet med uppsatsen var att undersöka samband mellan fysisk aktivitet och depression, stress, och välmående, med kontroll för eventuellt samvarierande demografiska faktorer. Urvalet bestod av 357 (ålder 25-80år, 49.3% kvinnor) deltagare från Betulastudien. Välmående undersöktes med två frågor som skattades 0-10. Depressiva symtom undersöktes med The Center for Epidemiologic Studies Depression Scale. Stress undersöktes med Perceived Stress Questionnaire. Mängd fysisk aktivitet undersöktes genom tre frågor som efterfrågade mängd fysisk aktivitet: (1) de senaste 12 månaderna, (2) en vanlig vecka och (3) jämfört med andra. Samband undersöktes med hierarkisk regression, med kontroll för civilstånd, kön, utbildning och ålder. Fysisk aktivitet var svagt associerat med Välmående (ΔR² = .023) och endast aktivitet i jämfört med andra (β = .132) var signifikant. Fysisk aktivitet var positivt associerat med välmående men förklarade endast en liten del i variansen. Avsaknad av statistiskt signifikanta samband mellan fysisk aktivitet, depression och stress skiljer sig från tidigare populationsbaserade studier. Dessa skillnader i resultat skulle kunna förklaras med kulturella och metodologiska skillnader. Ytterligare forskning på sambandet mellan fysisk aktivitet och psykisk hälsa behövs. / Physical activity contributes to several positive physiological health benefits and has also, in a number of studies, proven to contribute to psychological health. There are nonetheless studies which have not been able to prove the positive effects on psychological health. The goal of the paper was to investigate correlations between physical activity and depression, stress, and wellbeing, while controlling for the influence of demographical factors. The sample was from the Betula study and consisted of 357 participants aged 25-80, with 49.3% women. Wellbeing was assessed by ratings (0-10) in response to two questions. Depressive symptoms were measured by the Center for Epidemiologic Studies Depression Scale. Stress was measured by Perceived Stress Questionnaire. Amount of physical activity was investigated through three questions which asked for the amount of physical activity: (1) in the last 12 months, (2) a normal week, and (3) compared to others. Relationships between activity level and aspects of psychological health were investigated through hierarchical regression analysis, controlling for civil status, gender, education, and age. Physical activity was weakly associated with Wellbeing (ΔR² = .023) and only activity compared to others (β = .132) was significant. Physical activity had a positive association with wellbeing, but only accounts for a small amount of the variance. The absence of statistical significant relationship between physical activity, depression and stress is not in line with previous population-based studies. These differences could possibly be explained by cultural and methodological difference between studies. Additional studies on the correlation between physical activity and mental health is needed.

No description available.

Sedan 80-talet har man i Sverige på försöksnivå anlagt små bestånd av masurbjörk, stora kunskapsluckor finns framförallt hur man säljer och vem man säljer virket till. Arbetet syftar till att beskriva marknaden för masurbjörk samt att beräkna virkesvärdet hos två bestånd i Västerbotten. Arbetet bygger på en marknadsundersökning och en fältstudie. I Sverige köper knivtillverkare masurbjörk årligen, det går även att sälja till finska virkesköpare. För de två undersökta bestånden i Västerbotten, 15 år gamla beräknades virkesvärde till ~9400 kr/Ha respektive ~7000kr/Ha. Om man sköter ett masurbjörksbestånd finns det stor chans att få hög avsättning för virket även i framtiden.

Temperature is commonly suggested to be the most important regulating factor for the position of the treeline. But also other abiotic and biotic processes may influence. To understand treeline shifts, it is necessary to improve the knowledge about the treeline forming species and their establishment, growth and survival. What are the drivers behind the shifts? The abundance of other vegetation is previously reported to facilitate growth of seedlings above treeline and also warmer temperatures are commonly observed to improve growth.   This study observed growth of mountain birch seedlings during one growing season. The relative importance of environmental factors in relation to the amount of growth and abundance was investigated. The study was conducted in the area of Abisko, Northern Sweden, using 4 sites, where transects were established just above the treeline. The sites differed in the amount of mean precipitation and aspect of the slopes. The vegetation composition around the seedlings and at the average treeline was observed, soil temperatures measured and the aspect of the slope estimated   Seedling growth was observed at all sites, with the highest amount in the sites with most precipitation, Pålnoviken and Katterjåkk. The observed soil mean and maximum temperatures were consistently highest in the southern facing slopes of Jiebrenjåkk and Pålnoviken. The vegetation was mostly dominated by dwarf shrubs, herbaceous plant cover, mosses and bare ground, and did not differ between the seedlings and the average treeline. The best model for growth was found to be the combination of the factors site, herbaceous plant cover, litter and soil mean temperature. Herbaceous plant cover was observed to improve the amount of growth in the drier sites of Pålnoviken and Jiebrenjåkk.   The finding of mountain birch seedlings growing in all vegetation types along the treeline, indicates that they have no preference of vegetation type for establishment. However, the negative influence of bare ground on growth supports the theory that abundance of vegetation facilitates growth of seedlings. The highest amount of growth was found in the sites with most precipitation, suggesting this to be an important factor for growth. In contrast to the expectations, warmer soil temperatures and the south facing slopes did not affect growth positively. This could be explained by the extremely high temperatures of the summer that may have induced drought. Finally, the improved growth by herbaceous plant cover in the drier sites may be because of their preference of moisture and nutrient rich soils, that could also support the growth of mountain birch seedlings.

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2008. / Härtill 4 uppsatser.

Master of Science / Department of Horticulture and Natural Resources / Jason Griffin / Chad T. Miller / Oak trees (Quercus L.) and river birch (Betula nigra L.) are two horticulturally significant crops widely used in landscapes but notorious for developing iron (Fe) induced interveinal foliar chlorosis (IFC) in alkaline soils. Variation in IFC has been observed between species of oak and provenances of river birch suggesting that species and provenances endemic to alkaline soils do not always display this chlorosis. Limited studies investigating the effect of elevated pH on oak and river birch have been conducted. More environmentally tolerant and aesthetically pleasing selections could be used if they are first screened to determine their adaptability to high pH soils. Three experiments were conducted to evaluate Texas red oak (Quercus buckleyi Nixon and Dorr) and Durand oak [Quercus sinuata Walter var. breviloba (Torr.) C.H. Mull.] with landscape collections of pin oak (Quercus palustris L.) to determine the extent of IFC when grown at elevated pH. When grown in an elevated pH substrate, pin oak was unable to maintain elevated leaf total leaf Fe concentrations, consistently developed IFC, and exhibited low total leaf chlorophyll concentrations compared to non-chlorotic pin oak seedlings in the control pH substrate. Texas red oak and Durand in the elevated substrate did not develop IFC and maintained high leaf chlorophyll concentrations compared to controls; they also sequestered greater amounts of substrate Fe in leaves compared to pin oak in the elevated substrates. Another crop of ornamental significance and widely planted in the landscape, river birch (Betula nigra L.), develops IFC in high pH soils. Two experiments evaluated river open- pollinated (OP) seedlings of Iowa provenances, OP ‘BNMTF, and clones from selected Iowa provenances, ‘BNMTF’, ‘Cully’ in an elevated pH substrate. A seed source from Bearbower Sand Prairie, Buchanan Co., IA (BSP3) had greater leaf chlorophyll than ‘BNMTF’OP, and a clone from Clemons Creek WMA, Washington Co., IA (CCWMA3) than the trade standard ‘Cully’. Although differences in total leaf chlorophyll were observed, all sources in elevated pH substrate did not sequester sufficient amounts of leaf Fe compared to their controls. Field evaluations with considerations of provenance performance in different hardiness zones should be used to determine the potential of these Iowa sources as more suitable selections for use in landscapes with alkaline soils.