Influence of Plastic Dissipation on Apparent Fracture Energy Determined by a Three-Point Beding Test

A three-point bending test used for determining the fracture energy in modus I for wood perpendicular to the grain is studied, If the height of the specimen is varied, the results show a size effect, The specimens used in testing have been analyzed by finite element calculations with an anisotropic elasto-plastic material model in order to determine the influence of plastic dissipation. Analysis has been performed for three sizes of specimens where the height and length have been varied. The computational results are compared with experimental results

Estimating biomass and soil carbon change at the level of forest stands using repeated forest surveys assisted by airborne laser scanner data

BackgroundUnder the growing pressure to implement mitigation actions, the focus of forest management is shifting from a traditional resource centric view to incorporate more forest ecosystem services objectives such as carbon sequestration. Estimating the above-ground biomass in forests using airborne laser scanning (ALS) is now an operational practice in Northern Europe and is being adopted in many parts of the world. In the boreal forests, however, most of the carbon (85%) is stored in the soil organic (SO) matter. While this very important carbon pool is "invisible" to ALS, it is closely connected and feeds from the growing forest stocks. We propose an integrated methodology to estimate the changes in forest carbon pools at the level of forest stands by combining field measurements and ALS data.ResultsALS-based models of dominant height, mean diameter, and biomass were fitted using the field observations and were used to predict mean tree biophysical properties across the entire study area (50 km(2)) which was in turn used to estimate the biomass carbon stocks and the litter production that feeds into the soil. For the soil carbon pool estimation, we used the Yasso15 model. The methodology was based on (1) approximating the initial soil carbon stocks using simulations; (2) predicting the annual litter input based on the predicted growing stocks in each cell; (3) predicting the soil carbon dynamics of the annual litter using the Yasso15 soil carbon model. The estimated total carbon change (standard errors in parenthesis) for the entire area was 0.741 (0.14) Mg ha(-1) yr(-1). The biomass carbon change was 0.405 (0.13) Mg ha(-1) yr(-1), the litter carbon change (e.g., deadwood and leaves) was 0.346 (0.027) Mg ha(-1) yr(-1), and the change in SO carbon was - 0.01 (0.003) Mg ha(-1) yr(-1).ConclusionsOur results show that ALS data can be used indirectly through a chain of models to estimate soil carbon changes in addition to changes in biomass at the primary level of forest management, namely the forest stands. Having control of the errors contributed by each model, the stand-level uncertainty can be estimated under a model-based inferential approach

Hip and fragility fracture prediction by 4-item clinical risk score and mobile heel BMD: a women cohort study

<p>Abstract</p> <p>Background</p> <p>One in four Swedish women suffers a hip fracture yielding high morbidity and mortality. We wanted to revalidate a 4-item clinical risk score and evaluate a portable heel bone mineral density (BMD) technique regarding hip and fragility fracture risk among elderly women.</p> <p>Methods</p> <p>In a population-based prospective cohort study we used clinical risk factors from a baseline questionnaire and heel BMD to predict a two-year hip and fragility fracture outcome for women, in a fracture preventive program. Calcaneal heel BMD was measured by portable dual X-ray laser absorptiometry (DXL) and compared to hip BMD, measured with stationary dual X-ray absorptiometry (DXA) technique.</p> <p>Results</p> <p>Seven women suffered hip fracture and 14 women fragility fracture/s (at hip, radius, humerus and pelvis) among 285 women; 60% having heel BMD ≤ -2.5 SD. The 4-item FRAMO (Fracture and Mortality) Index combined the clinical risk factors age ≥80 years, weight <60 kg, prior fragility fracture, and impaired rise-up ability. Women having 2-4 risk factors showed odds ratio (OR) for hip fracture of 5.9 and fragility fracture of 4.4. High risk group hip fracture risk was 2.8% annually compared to 0.5% for the low risk majority (69%). Heel BMD showed hip fracture OR of 3.1 and fragility fracture OR of 2.6 per SD decrease. For 30 DXA assessed participants mean hip BMD at -2.5 SD level corresponded to a lower BMD at the heel. Five of seven hip fractures occurred within a small risk group of 32 women, identified by high FRAMO Index + prior fragility fracture + heel T-score ≤-3.5 SD.</p> <p>Conclusions</p> <p>In a follow-up study we identified high risk groups for hip and fragility fracture with our plain 4-item risk model. Increased fracture risk was also related to decreasing heel BMD in calcaneal bone, measured with a mobile DXL technique. A combination of high FRAMO Index, prior fragility fracture, and very low BMD restricted the high risk group to 11%, among whom most hip fractures occurred (71%). These practical screening methods could eventually reduce hip fracture incidence by concentrating preventive resources to high fracture risk women.</p

Taller and slenderer trees in Swedish forests according to data from the National Forest Inventory

Changes over time in annual basal area growth and mean height for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) over the period, 1983-2020 were studied using sample tree data from temporary plots recorded in the Swedish National Forest Inventory. The annual basal area growth was derived from the last measured full ring on increment cores. Using 20 to 60-year-old dominant trees, the mean height and annual basal area growth were examined as functions of tree, stand and site conditions, and trends were assessed mainly using residual analyses over time. A significant increase in mean height at a given age was found for both species, but the annual basal area growth level remained stable over the 38-year period. Currently, at a given age of 50 annual rings at breast height, the mean heights of pines and spruces increased on average by 10.1% (i.e. similar to 2 m), compared to 50 year-old pines and spruces in the 1980s, and the increase was similar in the different regions. The results suggest that trees have become taller and slenderer in Swedish forests. Increasing tree height over time at a given age in Northern Europe has been documented in several reports and many causes have been suggested, such as changed forest management, increasing temperatures and nitrogen deposition. We suggest that elevated CO2 in the air and improved water-use efficiency for the trees might also be strong drivers

A new sampling strategy for forest inventories applied to the temporary clusters of the Swedish national forest inventory

A new sampling strategy for forest inventories is presented. The most important difference from the traditional sampling strategies is that auxiliary variables from remote sensing are incorporated into the sampling design. The sample is selected to match population distributions of the auxiliary variables as well as possible. This is achieved by a double sampling approach, where auxiliary variables are extracted for a large first-phase sample. The second selection is done by the local pivotal method and produces an even thinning of the first-phase sample. Thus, we make sure that the selected second-phase sample becomes much more representative of the population than what is possible by the use of traditional designs. The potential of implementing the new strategy for the temporary clusters within the Swedish national forest inventory is evaluated with five auxiliary variables: the geographical coordinates, elevation, predicted tree height, and predicted basal area. The increased representativity that we achieve with the new strategy induces up to 95% reduction of the variance of the sample means of the remote sensing auxiliary variables compared with traditional designs. For this reason, we conclude that the new strategy that will be implemented in the forthcoming Swedish national forest inventory has a great potential to achieve large improvements in estimation of many important forest attributes

Braaten-Pisarski Method at Finite Chemical Potential

The effective perturbation theory developed by Braaten and Pisarski for gauge theories at finite temperature is extended to finite chemical potential. As a first application the collisional energy loss of a heavy quark propagating through a quark-gluon plasma with non-vanishing quark chemical potential is considered. Assuming $\mu /T\simeq 1$, motivated by numerical simulations of heavy ion collisions at RHIC energies, we find that the effect of the quark chemical potential is rather small, unless the energy density instead of the temperature is fixed.Comment: 14 pages, REVTEX, 6 postscript figures appended, UGI-94-1

Primary care physicians’ experiences of carrying out consultations on the internet

Background The internet is increasingly used for health matters, including consulting a doctor. Primary care physicians (general practitioners) will probably be involved in performing text-based consultations on the internet as a complement to physical meetings. In the present study, we explored the experiences of GPs already performing consultations on the internet: the challenges, worries and educational demands of the task. Materials and methods A questionnaire was given to 21 GPs performing consultations on the internet for a public, non-commercial ‘ask the doctor’ service. The questionnaire was carried out at a meeting or sent by mail. The doctors answered a total of 28 questions, 12 of which included graded alternatives. Results The participating GPs were stimulated and challenged by performing consultations on the internet with previously unknown enquirers, in spite of limitations caused by the lack of personal meetings and physical examinations. The participants experienced a high educational value as a result of the problem-based learning situation induced by unfamiliar questions. The asynchronous feature was appreciated as it allowed time to reflect and perform relevant information searches before replying. Prior training and long-term experience as a family doctor were recommended before embarking on this method of consultation. Conclusions We conclude that the GPs studied experienced their new role as internet doctors mainly in a positive way, with some limitations. With the increase in consultations on the internet, training in this technique should be integrated into the curricula of medical schools and of continuous professional development (CPD)

Two modes of acupuncture as a treatment for hot flushes in men with prostate cancer – a prospective multicenter study with long-term follow-up. Eur Urol

Ö stergö tland, Norrkö ping and Linkö ping, Sweden e u r o p e a n u r o l o g y 5 5 ( 2 0 0 9 ) 1 5 6 -1 6 3 a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e u r o p e a n u r o l o g y . c o m 3) at baseline in the EA group to 4.1 (IQR, 2.0-6.5) ( p = 0.012) after 12 wk, and from 5.7 (IQR, 5.1-9.5) in the TA group to 3.4 (IQR1.8-6.3) ( p = 0.001). Distress by flushes decreased from 8.2 (IQR, 6.5-10.7) in the EA group to 3.3 (IQR, 0.3-8.1) ( p = 0.003), and from 7.6 (IQR, 4.7-8.3) to 3.4 (IQR, 2.0-5.6) ( p = 0.001) in the TA group after 12 wk, (78% and 73% reduction in &apos;&apos;hot flush score,&apos;&apos; respectively). The effect lasted up to 9 mo after treatment ended. CGRP did not change significantly. Few, minor side effects were reported. Article info Limitations: small number of patients; no placebo control, instead a small group controlled for 6 wk pretreatment. Conclusions: EA and TA lowered number of and distress from hot flushes. The hot flush score decreased 78% and 73%, respectively, in line with or better than medical regimens for these symptoms. Acupuncture should be considered an alternative treatment for these symptoms, but further evaluation is needed, preferably with a non-or placebo-treated control group

Harvested area did not increase abruptly—how advancements in satellite-based mapping led to erroneous conclusions

Using satellite-based maps, Ceccherini et al. (2020) report abruptly increasing harvested area estimates in several EU-countries beginning in 2015. They identify Finland and Sweden as countries with the largest harvest increases and the biggest potential effect on the EU’s climate policy strategy. Using more than 120,000 field reference observations to analyze the satellite-based map employed by Ceccherini et al. (2020) we found that the map’s ability to detect harvested areas abruptly increases after 2015. While the abrupt detected increase in harvest is merely an artifact, Ceccherini et al. (2020) interpret this difference as an indicator of increasing intensity in forest management and harvesting practice. In their response to comments, Ceccherini et al. (2021) revised their estimates to some degree but still used inadequate methods leading to an overestimation of harvested area in Finland and Sweden. Ceccherini, G. et al. (2020). Abrupt increase in harvested forest area over Europe after 2015. Nature 583, 72-77. Ceccherini, G., et al. (2021). Reply to Wernick, IK et al.; Palahí, M. et al. Nature 592(7856): E18-E23.Includes smaller additions to the text compared to version 1.