Effect of photoperiod and fertilization on shoot and fine root growth in Picea abies seedlings

seedlings were given three different fertilization treatments in the nutrient solution by varying the potassium:nitrogen (K:N) ratios (2.5, 3.0 or 3.9 g g). All fertilization treatments were combined with short-day (SD) treatment or no such treatment (control). Above- and belowground growth responses in the seedlings were analyzed. The SD treatment resulted in significantly reduced shoot height, compared to untreated control, irrespective of K:N ratio. No combination of photoperiod treatment or fertilization treatment affected the root collar diameter. In the current year root fraction with diameter <â0.5 mm, the highest K:N ratio led to significantly increased root length in control plants. In each 0.1 mm root diameter class up to 0.5 mm, the highest K:N ratio significantly stimulated root growth in control plants, while the effect was less evident for SD plants. SD treatment stimulated length growth in some fine root diameter classes. We conclude that SD treatment is a good and sufficient measure to reduce height growth without compromising fine root growth of P. abies seedlings. Fertilization treatment did not significantly improve aboveground growth in SD treated seedlings, and only limited effects on root growth was seen on control plants.Picea abiesâ

Dagens høye gjeldsnivå: en trussel for boligmarkedet? : en empirisk studie av boligprisenes rentefølsomhet og i hvilken grad denne kan forsterkes av sårbarheten til husholdningene

Norske husholdninger sin gjeld er i dag på rekordhøye nivåer. Det lave rentenivået fører derimot til at gjelden ikke oppleves som særlig belastende for den private økonomien. Motivasjonen bak denne utredningen er å undersøke hvor sårbare norske husholdninger er ved økte utlånsrenter og om denne sårbarheten kan påvirke boligmarkedet. I første del av analysen finner vi klare holdepunkter for at boligprisene er betydelig følsomme for økninger i utlånsrentene og at denne følsomheten har blitt sterkere de siste ti årene. Både kortsiktige og langsiktige fluktuasjoner i boligprisene kan forklares av renteendringer. Bankenes utlånsrenter påvirker boligprisene ved at de reelle bokostnadene øker og lønnsomheten av å investere i bolig reduseres. Dette fører til at både etterspørselen og tilbudet av boliger reduseres. Samtidig spiller rentene en rolle for husholdningenes forventninger. I andre del av analysen finner vi at selv ved store økninger i utlånsrentene er norske husholdninger i stand til å betjene gjelden sin. Dette gjelder til en viss grad også husholdningene med de høyeste gjeldsnivåene. Disse funnene må ses i lys av den høye private forbruksveksten som har funnet sted i Norge. Ved økte renteutgifter har husholdningene mulighet til å kutte i forbruket for å kunne betjene boliglånene sine. Sårbarheten oppfattes derfor ikke som en direkte trussel for boligmarkedet, men kan trolig slå ut i redusert forbruk og gjennom dette påvirke boligprisene. Erfaringene fra bankkrisen på slutten av 1980-tallet, hvor bedriftenes inntjeningsevne ble betydelig svekket, tilsier at gjeldsnivåene blant husholdningene bør vekke bekymring

Effects of mild drought on the morphology of sun and shade needles in 20-year-old Norway spruce trees

Several studies have looked at how individual environmental factors influence needle morphology in conifer trees, but interacting effects between drought and canopy position have received little attention. In this study, we characterized morphological responses to experimentally induced drought stress in sun exposed and shaded current-year Norway spruce needles. In the drought plot trees were suffering mild drought stress, with an average soil water potential at 50 cm depth of -0.4 MPa. In general, morphological needle traits had greater values in sun needles in the upper canopy than in shaded needles in the lower canopy. Needle morphology 15 months after the onset of drought was determined by canopy position, as only sun needle morphology was affected by drought. Thus, canopy position was a stronger morphogenic factor determining needle structure than was water availability. The largest influence of mild drought was observed for needle length, projected needle area and total needle area, which all were reduced by ~27% relative to control trees. Needle thickness and needle width showed contrasting sensitivity to drought, as drought only affected needle thickness (10% reduction). Needle dry mass, leaf mass per area and needle density were not affected 15 months after the onset of mild drought. Our results highlight the importance of considering canopy position as well as water availability when comparing needle structure or function between conifer species. More knowledge about how different canopy parts of Norway spruce adapt to drought is important to understand forest productivity under changing environmental conditions.publishedVersio

Depression trajectories and cytokines in schizophrenia spectrum disorders - A longitudinal observational study

Depression occurs frequently in all phases of schizophrenia spectrum disorders. Altered activity in the immune system is seen in both depression and schizophrenia. We aimed to uncover depressive trajectories in a sample of 144 adult individuals with schizophrenia spectrum disorders followed for one year, in order to identify possible cytokine profile differences. Patients were assessed longitudinally with the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS), where a score above 6 predicts depression. The serum cytokine concentrations for tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, IL-12p70 and IL-17A were measured using immunoassays. Latent growth curve models, multilevel models and latent class growth analysis (LCGA) were applied. The LCGA model supported three latent classes (trajectories) with differing CDSS profiles during the one-year follow-up: a high CDSS group (40.8 % of participants), a moderate CDSS group (43.9 %) and a low CDSS group (15.3 %). Five single PANSS items predicted affiliation to depressive trajectory: hallucinations, difficulty in abstract thinking, anxiety, guilt feelings and tension. In the high CDSS group, despite diminishing psychotic symptoms, depressive symptoms persisted throughout one year. The pro-inflammatory cytokines IFN-γ, IL-1β and TNF-α were differentially distributed between the depressive trajectories, although levels remained remarkably stable throughout 12 months. Significant changes were found for the anti-inflammatory cytokine IL-10 at baseline with an accompanying difference in change over time. More research is required to optimize future treatment stratification and investigate the contribution of inflammation in depressed patients with schizophrenia spectrum disorders.publishedVersio

Fine-root turnover rates of European forests revisited: an analysis of data from sequential coring and ingrowth cores

Background and Aims Forest trees directly contribute to carbon cycling in forest soils through the turnover of their fine roots. In this study we aimed to calculate root turnover rates of common European forest tree species and to compare them with most frequently published values. Methods We compiled available European data and applied various turnover rate calculation methods to the resulting database. We used Decision Matrix and Maximum-Minimum formula as suggested in the literature. Results Mean turnover rates obtained by the combination of sequential coring and Decision Matrix were 0.86 yr−1 for Fagus sylvatica and 0.88 yr−1 for Picea abies when maximum biomass data were used for the calculation, and 1.11 yr−1 for both species when mean biomass data were used. Using mean biomass rather than maximum resulted in about 30 % higher values of root turnover. Using the Decision Matrix to calculate turnover rate doubled the rates when compared to the Maximum-Minimum formula. The Decision Matrix, however, makes use of more input information than the Maximum-Minimum formula. Conclusions We propose that calculations using the Decision Matrix with mean biomass give the most reliable estimates of root turnover rates in European forests and should preferentially be used in models and C reporting

Hvordan kan sykepleier bidra til å redusere smerter hos pasienter med prostatakreft med skjelettmetastaser?

Bacheloroppgave 201

Linear Programming on the Cell/BE

Linear programming is a form of mathematical optimisation in which one seeks to optimise a linear function subject to linear constraints on the variables. It is a very versatile tool that has many important applications, one of them being modelling of production and trade in the petroleum industry. The Cell Broadband Engine, developed by IBM, Sony and Toshiba, is an innovative multicore architecture that has already been proven to have a great potential for high performance computing. However, developing applications for the Cell/BE is challenging, particularily due to the low-level memory management that is mandated by the architecture, and because careful optimisation by hand is often required to get the most out of the hardware. In this thesis, we investigate the opportunities for implementing a parallel solver for sparse linear programs on the Cell/BE. A parallel version of the standard simplex method is developed, and the ASYNPLEX algorithm by Hall and McKinnon is partially implemented on the Cell/BE. We have met substantial challenges when it comes to numerical stability, and this has prevented us from spending sufficient time on Cell/BE-specific optimisation and support for large data sets. Our implementations can therefore only be regarded as proofs of concept, but we provide analyses and discussions of several aspects of the implementations, which may guide the future work on this topic