Träddelsuttag eller massavedsuttag i förstagallring?

The purpose of this study is to compare the economic differences between withdraw of forest fuel and withdraw of pulpwood in first thinning, to see which method gives the maximum profitability (income - cost). Another purpose is to investigate the economic impact of the thicket cleaning. The study compares four different methods: i) pulpwood output with thicket cleaning, ii) pulpwood output without thicket cleaning, iii) forest fuel output with thicket cleaning and iv) forest fuel output without thicket cleaning. The study was conducted in a 30-years old stand, dominated by spruce, outside Harg in Uppland. The method that generated the best economic net income was pulpwood without thicket cleaning. It generated a positive net of 1,383 SEK per hectare. Forest fuel output without thicket cleaning also generated a positive net in 720 kronor per hectare. On the other hand both methods with thicket cleaning generated a negative net. The results of this study show that the costs of the first thinning have a great importance for the economic result, and also that the brushing is quite expensive. In conclusion pulpwood thinning is still the best option in the first thinning and thicket cleaning may not always be a given action before thinning

In Vitro Investigation of Thiol-Functionalized Cellulose Nanofibrils as a Chronic Wound Environment Modulator

There is currently a huge need for new, improved therapeutic approaches for the treatment of chronic wounds. One promising strategy is to develop wound dressings capable of modulating the chronic wound environment (e.g., by controlling the high levels of reactive oxygen species (ROS) and proteases). Here, we selected the thiol-containing amino acid cysteine to endow wood-derived cellulose nanofibrils (CNF) with bioactivity toward the modulation of ROS levels and protease activity. Cysteine was covalently incorporated into CNF and the functionalized material, herein referred as cys-CNF, was characterized in terms of chemical structure, degree of substitution, radical scavenging capacity, and inhibition of protease activity. The stability of the thiol groups was evaluated over time, and an in vitro cytotoxicity study with human dermal fibroblasts was performed to evaluate the safety profile of cys-CNF. Results showed that cys-CNF was able to efficiently control the activity of the metalloprotease collagenase and to inhibit the free radical DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), activities that were correlated with the presence of free thiol groups on the nanofibers. The stability study showed that the reactivity of the thiol groups challenged the bioactivity over time. Nevertheless, preparing the material as an aerogel and storing it in an inert atmosphere were shown to be valid approaches to increase the stability of the thiol groups in cys-CNF. No signs of toxicity were observed on the dermal fibroblasts when exposed to cys-CNF (concentration range 0.1-0.5 mg/mL). The present work highlights cys-CNF as a promising novel material for the development of bioactive wound dressings for the treatment of chronic wounds

Microstructural simulation of dynamic recrystallization

A Monte Carlo model for dynamic recrystallization has been developed from earlier models used to simulate static recrystallization and grain growth. The model simulates dynamic recrystallization by adding recrystallization nuclei and stored energy continuously with time. The simulations reproduce many of the essential features of dynamic recrystallization. The stored energy of the system, which may be interpreted as a measure of the flow stress, goes through a maximum and then decays, monotonically under some conditions and in an oscillatory manner under others. The principle parameters that were studied were the rate of adding stored energy, [Delta]H, and the rate of adding nuclei, [Delta]N. As [Delta]H increases, for fixed [Delta]N, the oscillations decay more rapidly and the asymptotic energy rises. As [Delta]N increases again the oscillations decay more rapidly but the asymptotic stored energy decreases. The mean grain size of' the system also oscillates in a similar manner to the stored energy but out of phase by 90[deg]. The flow stress oscillations occurred for conditions which lead to both coarsening and refinement of the initial grain size. Necklacing of the prior grain structure by new grains were observed for low [Delta]H and high [Delta]N; it is, however, not an invariable feature of grain refinement. The initial grain size has a profound influence on the microstructure that evolves during the first cycle of recrystallization but at long times, a mean grain size is established which depends on the values of [Delta]H and [Delta]N alone. Comparison of the relationships between the energy storage rate, maximum and asymptotic stored energy and the grain size suggest that in physical systems the energy storage rate and the nucleation rate are coupled. Comparison of the simulation results with experimental trends suggests that the dependence of nucleation rate on storage should be positive but weak. All of these results were obtained without the addition of special parameters to the model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30270/1/0000671.pd

Tillstånd och trender för arter och deras livsmiljöer

2015 års upplaga av den svenska rödlistan är den fjärde i ordningen. Den är baserad på IUCN:s rödlistningskriterier och revideras vart femte år. I rödlistan bedöms risken som enskilda arter av djur, växter och svampar löper att försvinna från Sverige. Bedömningen utförs av ArtDatabankens medarbetare i samverkan med över 100 externa experter, indelade i 14 expertkommittéer för olika organismgrupper. Under arbetet med 2015 års rödlista har tillstånd och trender bedömts för 21 600 arter och 1 318 lägre taxa (apomiktiska arter, underarter och varieteter), sammanlagt ca 22 900 taxa. Av de bedömda arterna klassificerades 2 029 som hotade (kategorierna CR, EN och VU) och 4 273 som rödlistade (inkluderar även kategorierna NT, RE och DD). Förhållandet mellan antalet rödlistade och antalet bedömda arter ar 19,8 %, vilket är ungefär samma värde som 2010 och 2005. I denna rapport jämförs antalet och andelen rödlistade arter mellan olika organismgrupper, biotoper, substrat och påverkansfaktorer. Texten ar indelad i en allmän del och åtta kapitel inriktade på olika landskapstyper. Landskapstyperna utgör en grov indelning av landets miljöer enligt följande kategorier: Skog, Jordbrukslandskap, Urbana miljöer, Fjäll, Våtmarker, Sötvatten, Havsstränder och Havsmiljöer. Skogen och jordbrukslandskapet är de artrikaste landskapstyperna med 1 800 respektive 1 400 arter som har en stark anknytning dit, och ytterligare flera hundra arter som förekommer där mer sporadiskt. De faktorer som påverkar flest rödlistade arter i Sverige är skogsavverkning och igenväxning, som båda utgör ett hot mot vardera ca 30 % av de rödlistade arterna. Avverkning minskar arealen av skog där naturliga strukturer och naturlig dynamik upprätthålls, och den orsakar därmed förlust av livsmiljöer. Igenväxning orsakas av ett antal faktorer, bland annat upphörande hävd (bete och slåtter), gödsling, trädplantering och brist på naturliga störningsregimer som t.ex. regelbundna översvämningar kring vattendrag och sjöar. Andra viktiga påverkansfaktorer är fiske, torrläggning av våtmarker, tillbakagång hos värdarter (främst alm och ask som drabbats av invasiva svampsjukdomar), klimatförändringar och konkurrens från invasiva arter. IUCN:s rödlisteindex beräknas för ett urval av de bedömda organismgrupperna. Rödlisteindex visar att skillnaderna mellan rödlistorna från 2000, 2005, 2010 och 2015 är små. Ett par undantag finns dock. Groddjur och stora däggdjur har fått en något förbättrad situation sedan 2000. Totalt förefaller det ändå som att trycket mot Sveriges artstock har förblivit relativt konstant under de senaste 15 åren

Coffee and tea drinking in relation to the risk of differentiated thyroid carcinoma: results from the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

PURPOSE: Coffee and tea constituents have shown several anti-carcinogenic activities in cellular and animal studies, including against thyroid cancer (TC). However, epidemiological evidence is still limited and inconsistent. Therefore, we aimed to investigate this association in a large prospective study. METHODS: The study was conducted in the EPIC (European Prospective Investigation into Cancer and Nutrition) cohort, which included 476,108 adult men and women. Coffee and tea intakes were assessed through validated country-specific dietary questionnaires. RESULTS: During a mean follow-up of 14 years, 748 first incident differentiated TC cases (including 601 papillary and 109 follicular TC) were identified. Coffee consumption (per 100 mL/day) was not associated either with total differentiated TC risk (HRcalibrated 1.00, 95% CI 0.97-1.04) or with the risk of TC subtypes. Tea consumption (per 100 mL/day) was not associated with the risk of total differentiated TC (HRcalibrated 0.98, 95% CI 0.95-1.02) and papillary tumor (HRcalibrated 0.99, 95% CI 0.95-1.03), whereas an inverse association was found with follicular tumor risk (HRcalibrated 0.90, 95% CI 0.81-0.99), but this association was based on a sub-analysis with a small number of cancer cases. CONCLUSIONS: In this large prospective study, coffee and tea consumptions were not associated with TC risk.Cancer Research UK (14136 to EPIC-Norfolk; C570/A16491 and C8221/A19170 to EPIC-Oxford), Medical Research Council (1000143 to EPIC-Norfolk, MR/M012190/1 to EPIC-Oxford) (United Kingdom)

Specificity Effects of Amino Acid Substitutions in Promiscuous Hydrolases: Context-Dependence of Catalytic Residue Contributions to Local Fitness Landscapes in Nearby Sequence Space

Catalytic promiscuity can facilitate evolution of enzyme functions-a multifunctional catalyst may act as a springboard for efficient functional adaptation. We test the effect of single mutations on multiple activities in two groups of promiscuous AP superfamily members to probe this hypothesis. We quantify the effect of site-saturating mutagenesis of an analogous, nucleophile-flanking residue in two superfamily members: an arylsulfatase (AS) and a phosphonate monoester hydrolase (PMH). Statistical analysis suggests that no one physicochemical characteristic alone explains the mutational effects. Instead, these effects appear to be dominated by their structural context. Likewise, the effect of changing the catalytic nucleophile itself is not reaction-type-specific. Mapping of "fitness landscapes" of four activities onto the possible variation of a chosen sequence position revealed tremendous potential for respecialization of AP superfamily members through single-point mutations, highlighting catalytic promiscuity as a powerful predictor of adaptive potential.This research was funded by the Biological and Biotechnological Research Council (BBSRC) and the Human Frontiers Science Programme. C.D.B. was supported by a BBSRC studentship and the Cambridge European Trust

Multi-decadal changes in tundra environments and ecosystems: Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF).

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in sub-arctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies