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The analysis of forest management strategies at landscape and regional levels forms a vital part of finding viable directions that will satisfy the many services expected of forests. This article describes the structure and content of a stand simulator, GAYA, which has been adapted to Swedish conditions. The main advantage of the GAYA implementation compared to other resources is that it generates a large number of management programmes within a limited time frame. This is valuable in cases where the management programmes appear as activities in linear programming (LP) problems. Two methods that are engaged in the projections, a climate change response function and a soil carbon model, are designed to complement other methods, offering transparency and computational effectiveness. GAYA is benchmarked against projections from the Heureka system for a large set of National Forest Inventory (NFI) plots. The long-term increment for the entire NFI set is smaller for GAYA compared with Heureka, which can be attributed to different approaches for modelling the establishment of new forests. The carbon pool belonging to living trees shows the same trend when correlated to standing volume. The soil carbon pool of GAYA increases with increased standing volume, while Heureka maintains the same amount over the 100-year projection period.

The analysis of forest management strategies at landscape and regional levels forms a vital part of finding viable directions that will satisfy the many services expected of forests. This article describes the structure and content of a stand simulator, GAYA, which has been adapted to Swedish conditions. The main advantage of the GAYA implementation compared to other resources is that it generates a large number of management programmes within a limited time frame. This is valuable in cases where the management programmes appear as activities in linear programming (LP) problems. Two methods that are engaged in the projections, a climate change response function and a soil carbon model, are designed to complement other methods, offering transparency and computational effectiveness. GAYA is benchmarked against projections from the Heureka system for a large set of National Forest Inventory (NFI) plots. The long-term increment for the entire NFI set is smaller for GAYA compared with Heureka, which can be attributed to different approaches for modelling the establishment of new forests. The carbon pool belonging to living trees shows the same trend when correlated to standing volume. The soil carbon pool of GAYA increases with increased standing volume, while Heureka maintains the same amount over the 100-year projection period.

The analysis of forest management strategies at landscape and regional levels forms a vital part of finding viable directions that will satisfy the many services expected of forests. This article describes the structure and content of a stand simulator, GAYA, which has been adapted to Swedish conditions. The main advantage of the GAYA implementation compared to other resources is that it generates a large number of management programmes within a limited time frame. This is valuable in cases where the management programmes appear as activities in linear programming (LP) problems. Two methods that are engaged in the projections, a climate change response function and a soil carbon model, are designed to complement other methods, offering transparency and computational effectiveness. GAYA is benchmarked against projections from the Heureka system for a large set of National Forest Inventory (NFI) plots. The long-term increment for the entire NFI set is smaller for GAYA compared with Heureka, which can be attributed to different approaches for modelling the establishment of new forests. The carbon pool belonging to living trees shows the same trend when correlated to standing volume. The soil carbon pool of GAYA increases with increased standing volume, while Heureka maintains the same amount over the 100-year projection period.

The analysis of forest management strategies at landscape and regional levels forms a vital part of finding viable directions that will satisfy the many services expected of forests. This article describes the structure and content of a stand simulator, GAYA, which has been adapted to Swedish conditions. The main advantage of the GAYA implementation compared to other resources is that it generates a large number of management programmes within a limited time frame. This is valuable in cases where the management programmes appear as activities in linear programming (LP) problems. Two methods that are engaged in the projections, a climate change response function and a soil carbon model, are designed to complement other methods, offering transparency and computational effectiveness. GAYA is benchmarked against projections from the Heureka system for a large set of National Forest Inventory (NFI) plots. The long-term increment for the entire NFI set is smaller for GAYA compared with Heureka, which can be attributed to different approaches for modelling the establishment of new forests. The carbon pool belonging to living trees shows the same trend when correlated to standing volume. The soil carbon pool of GAYA increases with increased standing volume, while Heureka maintains the same amount over the 100-year projection period.

Climate change impacts on Europe's forests are becoming visible much sooner than previously anticipated. The increase in natural disturbances leads to tree mortality and raises concerns about the forest's adaptive potential to sustain vital ecosystem services. In this context, the regeneration phase is crucial and comprises the largest potential to adapt to new environmental conditions with long lasting implications. Yet, forest regeneration is particularly susceptible to climatic changes due to the many directly climate-dependent processes, such as seed production and germination but also seedling and sapling development. Models of forest dynamics (MFDs) are essential to describe, understand and predict the effects of changing environmental and management factors on forest dynamics and subsequently on associated ecosystem services. We review a large variety of MFDs with regard to their representation and climate sensitivity of regeneration processes. Starting with a description of the underlying biological processes, we evaluate the various approaches taking into account specific model purposes, and provide recommendations for future developments. We distinguish between models based on ecological principles and models based on empirical relationships. We found an ample mix of regeneration modelling approaches tailored to different model purposes. We conclude that current approaches should be refined to adequately capture altered regeneration trends. Specifically, refinement is needed for MFDs that rely on ecological principals, as they suffer from knowledge gaps and underrepresented processes, thereby limiting their ability to accurately simulate forest regeneration under climate change. Global vegetation models are strongly constrained by their weak representation of vegetation structure and composition, and need to include more detail regarding structural complexity and functional diversity. Models focused on timber yield often rely on strong assumptions regardin

The analysis of forest management strategies at landscape and regional levels forms a vital part of finding viable directions that will satisfy the many services expected of forests. This article describes the structure and content of a stand simulator, GAYA, which has been adapted to Swedish conditions. The main advantage of the GAYA implementation compared to other resources is that it generates a large number of management programmes within a limited time frame. This is valuable in cases where the management programmes appear as activities in linear programming (LP) problems. Two methods that are engaged in the projections, a climate change response function and a soil carbon model, are designed to complement other methods, offering transparency and computational effectiveness. GAYA is benchmarked against projections from the Heureka system for a large set of National Forest Inventory (NFI) plots. The long-term increment for the entire NFI set is smaller for GAYA compared with Heureka, which can be attributed to different approaches for modelling the establishment of new forests. The carbon pool belonging to living trees shows the same trend when correlated to standing volume. The soil carbon pool of GAYA increases with increased standing volume, while Heureka maintains the same amount over the 100-year projection period.

This report presents models that have been developed within a PhD project about continuous cover forestry systems. Each model is developed to serve as a sub-model to describe a specific process within a larger simulation or estimation context. The models are intended for use within simulation and optimization of continuous cover forestry management and competition-dependent branch size estimation. All models presented are representative for uneven-sized Norway spruce on moderate to fertile sites in southern Sweden, corresponding to site indexes between G27 and G34, and latitudes between 56° and 58°., Continuous cover forestry systems: interaction between management practice, wood quality and economic viability

This report presents models that have been developed within a PhD project about continuous cover forestry systems. Each model is developed to serve as a sub-model to describe a specific process within a larger simulation or estimation context. The models are intended for use within simulation and optimization of continuous cover forestry management and competition-dependent branch size estimation. All models presented are representative for uneven-sized Norway spruce on moderate to fertile sites in southern Sweden, corresponding to site indexes between G27 and G34, and latitudes between 56° and 58°., Continuous cover forestry systems: interaction between management practice, wood quality and economic viability

This report presents models that have been developed within a PhD project about continuous cover forestry systems. Each model is developed to serve as a sub-model to describe a specific process within a larger simulation or estimation context. The models are intended for use within simulation and optimization of continuous cover forestry management and competition-dependent branch size estimation. All models presented are representative for uneven-sized Norway spruce on moderate to fertile sites in southern Sweden, corresponding to site indexes between G27 and G34, and latitudes between 56° and 58°., Continuous cover forestry systems: interaction between management practice, wood quality and economic viability

This report presents models that have been developed within a PhD project about continuous cover forestry systems. Each model is developed to serve as a sub-model to describe a specific process within a larger simulation or estimation context. The models are intended for use within simulation and optimization of continuous cover forestry management and competition-dependent branch size estimation. All models presented are representative for uneven-sized Norway spruce on moderate to fertile sites in southern Sweden, corresponding to site indexes between G27 and G34, and latitudes between 56° and 58°., Continuous cover forestry systems: interaction between management practice, wood quality and economic viability

This report presents models that have been developed within a PhD project about continuous cover forestry systems. Each model is developed to serve as a sub-model to describe a specific process within a larger simulation or estimation context. The models are intended for use within simulation and optimization of continuous cover forestry management and competition-dependent branch size estimation. All models presented are representative for uneven-sized Norway spruce on moderate to fertile sites in southern Sweden, corresponding to site indexes between G27 and G34, and latitudes between 56° and 58°., Continuous cover forestry systems: interaction between management practice, wood quality and economic viability

This report presents models that have been developed within a PhD project about continuous cover forestry systems. Each model is developed to serve as a sub-model to describe a specific process within a larger simulation or estimation context. The models are intended for use within simulation and optimization of continuous cover forestry management and competition-dependent branch size estimation. All models presented are representative for uneven-sized Norway spruce on moderate to fertile sites in southern Sweden, corresponding to site indexes between G27 and G34, and latitudes between 56° and 58°., Continuous cover forestry systems: interaction between management practice, wood quality and economic viability

Our ageing, and increasingly overweight population demands better implant designs and testing methods. More realistic finite element method (FEM) models are a great approach to reduce costs of the implant design process. FEM models could be used to evaluate implant performance against lack of bone ingrowth and medial tibial collapse. Failed bone ingrowth of the tibial component can result in early loosening, suggested to occur due to high micromotions at the implant interface. Additionally, post-operative misalignment, high patient BMI, and stumbling accidents cause medial tibial collapse. These phenomena have been assessed via FEM, where a realistic simulation, adequate constitutive model, loads, and boundary conditions must be selected. Also, the implantation process must be included to account for bone deformations. The purpose of this study was to investigate which constitutive model better predicts implantation and subsequent micromotions, bone ingrowth, and medial collapse. A FEM model was created from a CT-scanned tibia implanted with a Monoblock and a Persona (Zimmer, Inc., Warsaw, IN) trabecular metal tibial components. Four activities were considered. Four different heterogeneous material models were used: A linear elastic (LE), a softening Von Mises (sVM) model, an ideal isotropic crushable foam (iICF) model, and a hardening isotropic crushable foam Model (hICF) model. The hardening function of the latter model was mathematically demonstrated and validated against existing data. Implantation was performed prior to every analysis. The resulting micromotions were compared to an ingrowth threshold of 40 um to estimate extent of ingrowth. The same material models were used to evaluate medial collapse under stumbling conditions. The ingrowth results of the Monoblock were compared to retrieval. Implant performance was evaluated between the Persona and NexGen. The hardening function was able to predict yield when compared to experimental data., Biomedical Engineering | Biomaterials and Tissue Biomechanics

Our ageing, and increasingly overweight population demands better implant designs and testing methods. More realistic finite element method (FEM) models are a great approach to reduce costs of the implant design process. FEM models could be used to evaluate implant performance against lack of bone ingrowth and medial tibial collapse. Failed bone ingrowth of the tibial component can result in early loosening, suggested to occur due to high micromotions at the implant interface. Additionally, post-operative misalignment, high patient BMI, and stumbling accidents cause medial tibial collapse. These phenomena have been assessed via FEM, where a realistic simulation, adequate constitutive model, loads, and boundary conditions must be selected. Also, the implantation process must be included to account for bone deformations. The purpose of this study was to investigate which constitutive model better predicts implantation and subsequent micromotions, bone ingrowth, and medial collapse. A FEM model was created from a CT-scanned tibia implanted with a Monoblock and a Persona (Zimmer, Inc., Warsaw, IN) trabecular metal tibial components. Four activities were considered. Four different heterogeneous material models were used: A linear elastic (LE), a softening Von Mises (sVM) model, an ideal isotropic crushable foam (iICF) model, and a hardening isotropic crushable foam Model (hICF) model. The hardening function of the latter model was mathematically demonstrated and validated against existing data. Implantation was performed prior to every analysis. The resulting micromotions were compared to an ingrowth threshold of 40 um to estimate extent of ingrowth. The same material models were used to evaluate medial collapse under stumbling conditions. The ingrowth results of the Monoblock were compared to retrieval. Implant performance was evaluated between the Persona and NexGen. The hardening function was able to predict yield when compared to experimental data., Biomedical Engineering | Biomaterials and Tissue Biomechanics

Background: A porous tantalum glenoid component for total shoulder replacements was introduced in 2003 to promote biologic ingrowth. However, reports of component failure prompted design modifications. The purpose of this study is to present the largest series to date, of TSR with the second-generation Trabecular Metal™ glenoid component. Method: A radiologic and clinical evaluation of the second-generation TM glenoid was conducted in consecutive cases of 76 shoulders (66 patients) with a mean follow-up of 43.2 months (range 24–72 months). Pre-operative VAS score, patient self-assessed ASES score, active shoulder range of motion, and radiologic assessment were recorded. Patients were recalled for latest follow-up clinical and radiologic evaluation. Results: On latest follow-up, the mean VAS scores (pre-op: 6.4–latest: 0.9) and ASES scores (pre-op: 36.9–latest: 88.5) improved. Active range of motion improved in all planes. There was no report of glenoid component migration, loosening, or humeral stem subsidence. The incidence of non-progressive radiolucency in the glenoid was 6.6 % (Franklin 1: 3 cases, Franklin 2: 2 cases). Post-operative complications involved dislocation (n = 2) which were reduced in ED, post-operative stiffness (n = 1), transient axillary nerve neuropraxia (n = 1), and supraspinatus tear which underwent arthroscopic repair at 16 months post-op. There were no revision surgeries for implant loosening nor glenoid component fracture at the peg–base plate junction. Conclusions: The modifications established in the second-generation TM glenoid resulted to improve early to mid-term survivorship and clinical outcomes in TSR, with promise of long-term implant stability through bony ingrowth. Level of evidence: Level IV, case series, treatment study.

The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots, even-aged mixed species forest plots, uneven-aged natural forest, uneven-aged selection forest and roadside plantattions of poplar. The FEM growth and yield data base is currently supervised by Jan den Ouden and Frits Mohren.

The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed., Peer Reviewed, Postprint (published version)

Background: Removal of biliary Fully Covered Self Expandable Metal Stents can fail due to stent migration and/or hyperplastic ingrowth/overgrowth. Methods: A case series of 5 patients with benign biliary strictures (2 post-cholecystectomy, 2 following liver transplantation and 1 related to chronic pancreatitis) is reported. The biliary stricture was treated by temporary insertion of Fully Covered Self Expandable Metal Stents. Stent removal failed due to proximal stent migration and/or overgrowth. Metal stent removal was attempted a few weeks after the insertion of another Fully Covered Metal Stent into the first one. Results: The inner Fully Covered Self Expandable Metal Stent compressed the hyperplastic tissue, leading to the extraction of both the stents in all cases. Two complications were reported as a result of the attempt to stents removal (mild pancreatitis and self-limited haemobilia). Conclusion: In the present series, the "SEMS in SEMS" technique revealed to be effective when difficulties are encountered during Fully Covered Self Expandable Metal Stents removal. © 2014 Editrice Gastroenterologica Italiana S.r.l., SCOPUS: ar.j, info:eu-repo/semantics/published

Endoscopic placement of esophageal Self-Expandable Metal Stents (SEMS) is a therapeutic option for post-surgical esophageal leaks. Partially covered SEMS are mainly designed for malignant esophageal strictures, but are used off-label to close post-surgical leaks due to their lower migration rate than fully covered SEMS, and better adherence to the esophageal wall. Partially covered esophageal SEMS can achieve post-surgical fistula healing, but their removal is difficult due to tissue ingrowth through the uncovered part. A challenging case of a difficult removal of a partially covered esophageal SEMS (remove the indefinite article) is (below) presented. © 2013 The Authors.

Background: Removal of biliary Fully Covered Self Expandable Metal Stents can fail due to stent migration and/or hyperplastic ingrowth/overgrowth. Methods: A case series of 5 patients with benign biliary strictures (2 post-cholecystectomy, 2 following liver transplantation and 1 related to chronic pancreatitis) is reported. The biliary stricture was treated by temporary insertion of Fully Covered Self Expandable Metal Stents. Stent removal failed due to proximal stent migration and/or overgrowth. Metal stent removal was attempted a few weeks after the insertion of another Fully Covered Metal Stent into the first one. Results: The inner Fully Covered Self Expandable Metal Stent compressed the hyperplastic tissue, leading to the extraction of both the stents in all cases. Two complications were reported as a result of the attempt to stents removal (mild pancreatitis and self-limited haemobilia). Conclusion: In the present series, the "SEMS in SEMS" technique revealed to be effective when difficulties are encountered during Fully Covered Self Expandable Metal Stents removal. © 2014 Editrice Gastroenterologica Italiana S.r.l., SCOPUS: ar.j, info:eu-repo/semantics/published

Det övergripande syftet med denna studie var att jämföra volymtillväxten i skog skött enligt principen Naturkultur, genom olika starka höggallringar, med skog skött enligt traditionellt trakthyggesbruk. För att besvara frågeställningarna hur volymtillväxt och inväxning skiljer sig mellan de olika behandlingarna utfördes en fältinventering, under sommaren 2012, av ett försök anlagt 1990-91. Försökslokalen var belägen i Åliden, 64ºN 20ºE, cirka 35 kilometer norr om Umeå. Försöket var anlagt i en sydvästsluttning 155 meter över havet och var tänkt att representera Västerbottens kustland. Försöket i Åliden ingick i en serie om tolv block med fyra behandlingar per block. Behandlingarna var dels två naturkulturbehandlingar där skog lämnats (Gles och Tät), en naturkulturbehandling där 90 procent av skogen avverkats och en behandling enligt traditionellt trakthyggesbruk (Kal och Kont). I behandlingarna Gles och Tät mättes totalt fyra provytor á 314 m2 inom respektive behandling. I Kal och Kont har fyra ytor kontrollmätts inom varje behandling i syfte att uppskatta ståndortsindex. Behandlingen Gles hade en tillväxt på 3,2 m3sk ha-1 år-1 men hade inte återhämtat det volymuttag som gjordes vid gallringen. Medeltillväxten sedan försöksutläggningen var likartad i Tät, 3,0 m3sk ha-1 år-1. Inväxningen förbi 6 centimeter i brösthöjd var 13 respektive 7 stammar ha-1 år-1 i Gles och Tät. Boniteten för behandlingarna Kal och Kont, vilken grundade sig på ståndortsindex uppskattat från trädens höjdutveckling. Kal och Kont hade en beräknad bonitet på 6,3 respektive 7,3 m3sk ha-1 år-1. Volymtillväxten i behandlingarna Gles och Tät hade en positiv korrelation med stående volym efter behandling., The overall aim of this study was to compare the silviculture principle Naturkultur with the even-aged silviculture system which is common in the Nordic countries today. To answer the question how the volume increment increment and recruitment vary between these two different management ideas a field trial established 1990-91 was re inventoried in the summer of 2012. The study area was situated in Åliden, 64ºN 20ºE, approximately 35 kilometres north of Umeå. The trail was placed on a southwest slope at 155 a. s. l. The site was supposed to represent the coastland of Västerbotten. The experimental site in Åliden was one of 12 sites with four treatments at each block. The different treatments that were tested consisted of three logging intervals according to Naturkultur and one traditional logging according to the even-aged clear-cut system. The loggings according to Naturkultur were named Kal, Gles and Tät with 90, 45 and 14 percent of the standing volume removed in the respective treatment. The traditional clear-cut was named Kont and here were 100 percent of the standing volume removed. The results from this study indicate that it takes 22 years for the treatment Tät to recover the volume loss due to harvesting. Even the treatment Gles had a good volume growth but did not reach the pre-harvesting level. Site productivity was similar for Gles and Tät with 3.2 respectively 3.0 m3sk ha-1 year-1, however site productivity for Kal and Kont was estimated to 6.3 respectively 7.3 m³sk ha-1 year-1. Volume yield was positively correlated with standing volume after treatment. The ingrowth past a dbh of 6 centimeters was 13 respectively 7 stems ha-1 år-1 in Gles and Tät.