Comparison of Phlebiopsis and urea and their effect when treating young spruces against Heterobasidion spp

Control of the economically important forest pathogen Heterobasidion spp. can be done by control with chemical and biological agents such as urea and Phlebiopsis. Today in Europe this action is mainly done during the mid stages of the rotation, thinning foremost and to a small extent in final felling. Studies have shown that the fungus is spreading not only in the late stage but also during the early pre commercial thinning stage, preventive actions should be taken also at this stage. In this thesis focus has been on investigating the differences in effectiveness of Phlebiopsis and urea. The aim was to compare the agents when used on small Norway spruce stumps in Sweden. The study was conducted at 18 sites distributed in southern and the central parts of Sweden. 1080 stumps were created and treated with Phlebiopsis and urea, 1/3 was left untreated as control. Results from the study show that stumps treated with urea wasn’t infected by Heterobasidion sp. Control stumps and Phlebiopsis treated stumps were infected by the fungus at the rate of 20,9 % and 8,1%. The effect of using Phlebiopsis decreases the infection frequency but doesn’t rule it out. This thesis also further consolidates the fact that small stumps of Norway spruce need protection against infection of Heterobasidion spp, where the treatment agent urea could be seen as more effective. Even though urea was more effective in this thesis, Phlebiopsis is an agent that also decreases the infection rate and it is significantly better to treat stumps after pre commercial thinning than to leave the stumps untreated. Urea is an agent that, with tax legislation today, is expensive to use and of this reason Phlebiopsis might still be the economically best agent to use.Behandling av den ekonomiskt viktiga trrädsjukdomen Heterobasidion spp. kan göras på kemisk väg med urea och biologiskt med Phlebiopsis. Idag i Europa behandlas i huvudsak bestånd i mellanstadiet, då i huvudsak i gallring och i viss utsträckning slutavverkning. Studier har visat att svampen kan spridas också i det tidigare stadiet röjning, behandling mot rotröta bör göras också här. Fokus för denna studie var att undersöka skillnaden i effektivitet för Phlebiopsis och urea. Målet var att studera medlen vid behandling av små unga granstubbar i röjningsstadiet i Sverige. Studien utfördes på 18 ytor fördelat i södra Sverige samt i mellersta Sverige. 1080 stubbar skapades och 1/3 behandlades med Phlebiopsis, 1/3 med urea samt lämnades 1/3 obehandlade som referens. Resultatet från studien visar att stubbar behandlade med urea ej blev infekterade av rottickan Heterobasidion spp. För kontrollstubbarna och Phlebiopsisbehandlade stubbar var infektionsfrekvensen 20,9% och 8,1 %. Phlebiopsis minskade infektionsfrekvensen men tog inte bort den helt. Denna studie styrker också ytterligare det faktum att granstubbar behöver ett skydd mot rotticka, här verkar urea vara mycket effektiv som behandlingsmedel. Även om urea var mer effektiv i denna studie, är Phlebiopsis också ett medel som minskar infektionsfrekvensen och är signifikant bättre än att inte behandla stubbarna efter röjning. Urea är idag ett medel som är dyrt att använda, då framförallt på grund av skatter, och detta kan göra att Phlebiopsis då är det ekonomiskt bästa medlet att använda

Contribution of Paranasal Sinuses to the Acoustic Properties of the Nasal Tract

Background: The contribution of the nasal and paranasal cavities to the vocal tract resonator properties is unclear. Here we investigate these resonance phenomena of the sinonasal tract in isolation in a cadaver and compare the results with those gained in a simplified brass tube model. Methods: The resonance characteristics were measured as the response to sine sweep excitation from an earphone. In the brass model the earphone was placed at the closed end and in the cadaver in the epipharynx. The response was picked up by a microphone placed at the open end of the model and at the nostrils, respectively. A shunting cavity with varied volumes was connected to the model and the effects on the response curve were determined. In the cadaver, different conditions with blocked and unblocked middle meatus and sphenoidal ostium were tested. Additionally, infundibulotomy was performed allowing direct access to and selective occlusion of the maxillary ostium. Results: In both the brass model and the cadaver, a baseline condition with no cavities included produced response curves with clear resonance peaks separated by valleys. Marked dips occurred when shunting cavities were attached to the model. The frequencies of these dips decreased with increasing shunting volume. In the cadaver, a marked dip was observed after removing the unilateral occlusion of the middle meatus and the sphenoidal ostium. Another marked dip was detected at low frequency after removal of the occlusion of the maxillary ostium following infundibulotomy. Conclusion: Combining measurements on a simplified nasal model with measurements in a cadaveric sinonasal tract seems a promising method for shedding light on the acoustic properties of the nasal resonator

Contribution of paranasal sinuses to the acoustic properties of the nasal tract

BACKGROUND The contribution of the nasal and paranasal cavities to the vocal tract resonator properties is unclear. Here we investigate these resonance phenomena of the sinonasal tract in isolation in a cadaver and compare the results with those gained in a simplified brass tube model. METHODS The resonance characteristics were measured as the response to sine sweep excitation from an earphone. In the brass model the earphone was placed at the closed end and in the cadaver in the epipharynx. The response was picked up by a microphone placed at the open end of the model and at the nostrils, respectively. A shunting cavity with varied volumes was connected to the model and the effects on the response curve were determined. In the cadaver, different conditions with blocked and unblocked middle meatus and sphenoidal ostium were tested. Additionally, infundibulotomy was performed allowing direct access to and selective occlusion of the maxillary ostium. RESULTS In both the brass model and the cadaver, a baseline condition with no cavities included produced response curves with clear resonance peaks separated by valleys. Marked dips occurred when shunting cavities were attached to the model. The frequencies of these dips decreased with increasing shunting volume. In the cadaver, a marked dip was observed after removing the unilateral occlusion of the middle meatus and the sphenoidal ostium. Another marked dip was detected at low frequency after removal of the occlusion of the maxillary ostium following infundibulotomy. CONCLUSION Combining measurements on a simplified nasal model with measurements in a cadaveric sinonasal tract seems a promising method for shedding light on the acoustic properties of the nasal resonator

Models for estimating the vertical distribution of the biomass on small diameter trees in early thinnings

I samband med nya mål för energiförbrukningen har behovet av förnyelsebara energislag ökat. Ett sätt att möta detta ökade behov i Sverige är ett ökat uttag av skogsbränsle. Denna ökning skulle till stor del kunna bestå av ökat bränsleuttag i skog med hög stamtäthet och klena träd. För att på ett mer rationellt sätt kunna göra åtgärder i skog av detta slag är det av stor vikt att på förhand kunna uppskatta hur mycket man ska ta ut och hur mycket man ska lämna kvar som näring åt kvarvarande bestånd. Syftet med detta arbete var att skapa funktioner med vilka man ska kunna skatta biomassafördelningen i vertikal ledd för klena träd. Framtagandet av funktionerna har gjorts genom regressionsanalyser. Funktionerna bygger på data från Kristina Ulvcronas avhandling Effects of Silvicultural Treatments in Young Scots pine-dominated Stands on the Potential for Early Biofuel Harvests. Vid regressionsanalyserna användes höjd samt kvadrering och kubering av höjd som förklarande variabler till den vertikala fördelningen av biomassa för tall, gran och björk. Även funktioner för fördelningen av stamved, stambark och grenar inkl. barr togs fram. Resultaten visar att med hjälp av våra funktioner kan man se att en stor del av biomassa finns långt ner i träden. Denna andel varierar dock mellan de olika trädslagen. För tall finner man att vid 75 % av trädhöjden finns 86 % av den totala biomassan med en förklaringsgrad på 99,8 %. För både gran och björk finns 93 % av biomassan vid 75 % av höjden. Dessa funktioner har förklaringsgrad (R2= 99,9 %). Dock är vissa konstanter icke signifikanta på signifikansnivån 0,05. Funktionerna i detta arbete skulle kunna integreras i en skördardator som ett hjälpmedel för optimal aptering. Dock krävs det att funktionerna vidareutvecklas med ett bredare dataunderlag då våra funktioner endast bygger på data från tre bestånd inom samma region (Västerbottens inland).In connection with the new targets for energy consumption, the need for renewable energy sources currently increase. One way to meet this increasing demand in Sweden is to increase the extraction of forest fuel. This increase could consist of a greater fuel extraction in forests with high stem density and small diameter trees, thus early thinnings. For a more rational way to make actions in forests of this kind it is of great importance to be able to estimate how much of the biomass to extract and how much to leave as nourish to the remaining stand. The aim of this work was to create functions with which you should be able to estimate the biomass distribution in the vertical direction of small diameter trees. When creating the functions regression analysis was used. The functions are based on data from Kristina Ulvcronas thesis Effects of Silvicultural Treatments in Young Scots pine- dominated Stands on the Potential for Early Biofuel Harvest. In the regression analysis height and squared and incubated height has been used as explanatory variables for the vertical distribution of biomass for pine, spruce and birch. Also functions for the distribution of wood, stem bark and branches and needles were developed. The results show that a large proportion of biomass is found far down in the trees. This proportion varies between the different tree species. For pine we found that at 75% of the height is 86% of the total biomass with a coefficient of determination of 99.8 %. For spruce and birch are 93% respectively 93% of the biomass at 75% of the height. These functions have the degree of explanation (R2=99.9%). However, certain constants are not significant at the 0.05 significance level. The functions in this work can be integrated into a harvester computer as a tool for the bucking to be done in an optimal way. However, it is required that the functions are developed with a broader data set as base, this because the functions are based only on data from three populations within the same region (the inland of Västerbotten)

A solid-state NMR study of changes in lipid phase induced by membrane-fusogenic LV-peptides

AbstractMembrane fusion requires restructuring of lipid bilayers mediated by fusogenic membrane proteins. Peptides that correspond to natural transmembrane sequences or that have been designed to mimic them, such as low-complexity “Leu-Val” (LV) peptide sequences, can drive membrane fusion, presumably by disturbing the lipid bilayer structure. Here, we assess how peptides of different fusogenicity affect membrane structure using solid state NMR techniques. We find that the more fusogenic variants induce an unaligned lipid phase component and a large degree of phase separation as observed in 31P 2D spectra. The data support the idea that fusogenic peptides accumulate PE in a non-bilayer phase which may be critical for the induction of fusion

Grid enabled virtual screening against malaria

34 pages, 5 figures, 3 tables, to appear in Journal of Grid Computing - PCSV, à paraître dans Journal of Grid ComputingWISDOM is an international initiative to enable a virtual screening pipeline on a grid infrastructure. Its first attempt was to deploy large scale in silico docking on a public grid infrastructure. Protein-ligand docking is about computing the binding energy of a protein target to a library of potential drugs using a scoring algorithm. Previous deployments were either limited to one cluster, to grids of clusters in the tightly protected environment of a pharmaceutical laboratory or to pervasive grids. The first large scale docking experiment ran on the EGEE grid production service from 11 July 2005 to 19 August 2005 against targets relevant to research on malaria and saw over 41 million compounds docked for the equivalent of 80 years of CPU time. Up to 1,700 computers were simultaneously used in 15 countries around the world. Issues related to the deployment and the monitoring of the in silico docking experiment as well as experience with grid operation and services are reported in the paper. The main problem encountered for such a large scale deployment was the grid infrastructure stability. Although the overall success rate was above 80%, a lot of monitoring and supervision was still required at the application level to resubmit the jobs that failed. But the experiment demonstrated how grid infrastructures have a tremendous capacity to mobilize very large CPU resources for well targeted goals during a significant period of time. This success leads to a second computing challenge targeting Avian Flu neuraminidase N1