Alley coppice—a new system with ancient roots

International audience& Context Current production from natural forests will not satisfy future world demand for timber and fuel wood, and new land management options are required. & Aims We explore an innovative production system that combines the production of short rotation coppice in wide alleys with the production of high-value trees on narrow strips of land; it is an alternative form of alley cropping which we propose to call 'alley coppice'. The aim is to describe this alley coppice system and to illustrate its potential for produc-ing two diverse products, namely high-value timber and ener-gy wood on the same land unit. & Methods Based on a comprehensive literature review, we compare the advantages and disadvantages of the alley cop-pice system and contrast the features with well-known existing or past systems of biomass and wood production. & Results We describe and discuss the basic aspects of alley coppice, its design and dynamics, the processes of competi-tion and facilitation, issues of ecology, and areas that are open for future research. & Conclusion Based on existing knowledge, a solid founda-tion for the implementation of alley coppice on suitable land is presented, and the high potential of this system could be shown

HLA-DP on Epithelial Cells Enables Tissue Damage by NKp44+ Natural Killer Cells in Ulcerative Colitis

Background & aims: Ulcerative colitis (UC) is characterized by severe inflammation and destruction of the intestinal epithelium, and is associated with specific risk single nucleotide polymorphisms in HLA class II. Given the recently discovered interactions between subsets of HLA-DP molecules and the activating natural killer (NK) cell receptor NKp44, genetic associations of UC and HLA-DP haplotypes and their functional implications were investigated.Methods: HLA-DP haplotype and UC risk association analyses were performed (UC: n = 13,927; control: n = 26,764). Expression levels of HLA-DP on intestinal epithelial cells (IECs) in individuals with and without UC were quantified. Human intestinal 3-dimensional (3D) organoid cocultures with human NK cells were used to determine functional consequences of interactions between HLA-DP and NKp44.Results: These studies identified HLA-DPA1∗01:03-DPB1∗04:01 (HLA-DP401) as a risk haplotype and HLA-DPA1∗01:03-DPB1∗03:01 (HLA-DP301) as a protective haplotype for UC in European populations. HLA-DP expression was significantly higher on IECs of individuals with UC compared with controls. IECs in human intestinal 3D organoids derived from HLA-DP401pos individuals showed significantly stronger binding of NKp44 compared with HLA-DP301pos IECs. HLA-DP401pos IECs in organoids triggered increased degranulation and tumor necrosis factor production by NKp44+ NK cells in cocultures, resulting in enhanced epithelial cell death compared with HLA-DP301pos organoids. Blocking of HLA-DP401-NKp44 interactions (anti-NKp44) abrogated NK cell activity in cocultures.Conclusions: We identified an UC risk HLA-DP haplotype that engages NKp44 and activates NKp44+ NK cells, mediating damage to intestinal epithelial cells in an HLA-DP haplotype-dependent manner. The molecular interaction between NKp44 and HLA-DP401 in UC can be targeted by therapeutic interventions to reduce NKp44+ NK cell-mediated destruction of the intestinal epithelium in UC

HLA-DPA1*02:01~B1*01:01 is a risk haplotype for primary sclerosing cholangitis mediating activation of NKp44+ NK cells

Objective Primary sclerosing cholangitis (PSC) is characterised by bile duct strictures and progressive liver disease, eventually requiring liver transplantation. Although the pathogenesis of PSC remains incompletely understood, strong associations with HLA-class II haplotypes have been described. As specific HLA-DP molecules can bind the activating NK-cell receptor NKp44, we investigated the role of HLA-DP/NKp44-interactions in PSC. Design Liver tissue, intrahepatic and peripheral blood lymphocytes of individuals with PSC and control individuals were characterised using flow cytometry, immunohistochemical and immunofluorescence analyses. HLA-DPA1 and HLA-DPB1 imputation and association analyses were performed in 3408 individuals with PSC and 34 213 controls. NK cell activation on NKp44/HLA-DP interactions was assessed in vitro using plate-bound HLA-DP molecules and HLA-DPB wildtype versus knock-out human cholangiocyte organoids. Results NKp44+NK cells were enriched in livers, and intrahepatic bile ducts of individuals with PSC showed higher expression of HLA-DP. HLA-DP haplotype analysis revealed a highly elevated PSC risk for HLA-DPA1*02:01~B1*01:01 (OR 1.99, p=6.7×10-50). Primary NKp44+NK cells exhibited significantly higher degranulation in response to plate-bound HLA-DPA1*02:01-DPB1*01:01 compared with control HLA-DP molecules, which were inhibited by anti-NKp44-blocking. Human cholangiocyte organoids expressing HLA-DPA1*02:01-DPB1*01:01 after IFN-γ-exposure demonstrated significantly increased binding to NKp44-Fc constructs compared with unstimulated controls. Importantly, HLA-DPA1*02:01-DPB1*01:01-expressing organoids increased degranulation of NKp44+NK cells compared with HLA-DPB1-KO organoids. Conclusion Our studies identify a novel PSC risk haplotype HLA-DP A1*02:01~DPB1*01:01 and provide clinical and functional data implicating NKp44+NK cells that recognise HLA-DPA1*02:01-DPB1*01:01 expressed on cholangiocytes in PSC pathogenesis

HLA-DP on Epithelial Cells Enables Tissue Damage by NKp44⁺ Natural Killer Cells in Ulcerative Colitis

Background &amp; Aims: Ulcerative colitis (UC) is characterized by severe inflammation and destruction of the intestinal epithelium, and is associated with specific risk single nucleotide polymorphisms in HLA class II. Given the recently discovered interactions between subsets of HLA-DP molecules and the activating natural killer (NK) cell receptor NKp44, genetic associations of UC and HLA-DP haplotypes and their functional implications were investigated. Methods: HLA-DP haplotype and UC risk association analyses were performed (UC: n = 13,927; control: n = 26,764). Expression levels of HLA-DP on intestinal epithelial cells (IECs) in individuals with and without UC were quantified. Human intestinal 3-dimensional (3D) organoid cocultures with human NK cells were used to determine functional consequences of interactions between HLA-DP and NKp44. Results: These studies identified HLA-DPA1∗01:03-DPB1∗04:01 (HLA-DP401) as a risk haplotype and HLA-DPA1∗01:03-DPB1∗03:01 (HLA-DP301) as a protective haplotype for UC in European populations. HLA-DP expression was significantly higher on IECs of individuals with UC compared with controls. IECs in human intestinal 3D organoids derived from HLA-DP401pos individuals showed significantly stronger binding of NKp44 compared with HLA-DP301pos IECs. HLA-DP401pos IECs in organoids triggered increased degranulation and tumor necrosis factor production by NKp44+ NK cells in cocultures, resulting in enhanced epithelial cell death compared with HLA-DP301pos organoids. Blocking of HLA-DP401–NKp44 interactions (anti-NKp44) abrogated NK cell activity in cocultures. Conclusions: We identified an UC risk HLA-DP haplotype that engages NKp44 and activates NKp44+ NK cells, mediating damage to intestinal epithelial cells in an HLA-DP haplotype–dependent manner. The molecular interaction between NKp44 and HLA-DP401 in UC can be targeted by therapeutic interventions to reduce NKp44+ NK cell–mediated destruction of the intestinal epithelium in UC.</p

Determining Juvenile-Mature Wood Transition in Scots Pine Using Latewood Density

Segmented regression models are applied successfully to estimate the cambial age of juvenile-mature wood transition in Scots pine sample trees from slow-grown stands. Mean ring density, earlywood, and latewood density profiles from 99 trees were determined by X-ray densitometric analysis of disks taken at 4-m stem height. The cambial age of transition from juvenile to mature wood is described according to segmented regression models based on latewood density profiles. The time series nature of the density data was considered by using generalized nonlinear regression and restricted maximum likelihood regression procedures. The quadratic-linear fit shows the transition at cambial age of about 22 with a standard deviation of 5 to 7 yr. Segmented regression models are an effective tool to get objective estimates of the juvenile-mature wood transition from density profiles

Modelling juvenile-mature wood transition in Scots pine (Pinus sylvestris L.) using nonlinear mixed-effects models

Nonlinear mixed-effects-models are applied successfully to estimate the cambial age of juvenile-mature wood transition in Scots pine sample trees from slow-grown stands. Till now segmented regression models are applied separately for each pith-to-bark-profile of wood density. The nonlinear mixed-effects-model overcomes this limitation while consistently and efficiently estimating the transition point for the whole sample. Furthermore standard errors can be calculated and impacts of stand and tree variables on the shape of pith-to-bark-curves can be tested. Mean ring density, earlywood, and latewood density profiles from 99 trees were determined by X-ray densitometric analysis of disks taken at 4-m stem height. The cambial age of transition from juvenile to mature wood is described according to nonlinear mixed-effects-models based on latewood density profiles. The time-series nature of the data are taken into account. The segmented quadratic-linear model shows the transition at cambial age of 21.77, which vary with the probability of 0.95 within the interval of [18.31; 26.85]. Impacts of tree variables or stands on the location of the transition point were not found, but impacts of stands on the shape of pith-to-bark-curves.Des modèles mixtes non linéaires ont été utilisés avec succès afin d'estimer l'âge (compté depuis la moelle) du passage bois juvénile-bois adulte pour des pins sylvestres provenant de peuplements à croissance lente. Jusqu'à présent, des modèles de régression segmentés étaient ajustés individuellement à chaque profil de densité du bois de la moelle à l'écorce. Le modèle mixte non linéaire permet de dépasser cette limitation en estimant de manière efficace et cohérente l'âge du point de passage pour l'ensemble de la population échantillonnée. En outre, des variances peuvent être estimées et les impacts des peuplements et des caractéristiques des arbres sur la forme des profils de densité du bois de la moelle à l'écorce peuvent être testés. À cette fin, les profils de densité moyenne de cerne, de densité du bois initial et de densité du bois final de 99 arbres ont été mesurés par exploration microdensitométrique de clichés radiographiques obtenus à partir d'échantillons prélevés dans des disques découpés à 4 mètres de hauteur. L'âge compté depuis la moelle du passage bois juvénile-bois adulte a été identifié à partir de modèles mixtes non linéaires appliqués aux profils de densité du bois final. La nature longitudinale des données a été prise en compte. Le modèle segmenté linéaire quadratique retenu permet d'identifier un âge moyen de passage du bois juvénile au bois adulte de 21,77 ans assorti d'un intervalle de confiance à 5 % de 18,31 à 26,85 ans. Si les impacts des variables "caractéristiques des arbres" et "peuplement" sur l'âge de passage bois juvénile-bois adulte n'ont pas été identifiés comme significatifs, le peuplement est apparu avoir un effet sur la forme des courbes d'évolution de la moelle à l'écorce du caractère considéré

Modelling juvenile-mature wood transition in Scots pine (Pinus sylvestris L.) using nonlinear mixed-effects models

Nonlinear mixed-effects-models are applied successfully to estimate the cambial age of juvenile-mature wood transition in Scots pine sample trees from slow-grown stands. Till now segmented regression models are applied separately for each pith-to-bark-profile of wood density. The nonlinear mixed-effects-model overcomes this limitation while consistently and efficiently estimating the transition point for the whole sample. Furthermore standard errors can be calculated and impacts of stand and tree variables on the shape of pith-to-bark-curves can be tested. Mean ring density, earlywood, and latewood density profiles from 99 trees were determined by X-ray densitometric analysis of disks taken at 4-m stem height. The cambial age of transition from juvenile to mature wood is described according to nonlinear mixed-effects-models based on latewood density profiles. The time-series nature of the data are taken into account. The segmented quadratic-linear model shows the transition at cambial age of 21.77, which vary with the probability of 0.95 within the interval of [18.31; 26.85]. Impacts of tree variables or stands on the location of the transition point were not found, but impacts of stands on the shape of pith-to-bark-curves.Modélisation du passage bois juvénile-bois adulte chez le pin sylvestre (Pinus sylvestris L.) à l’aide de modèles mixtes non linéaires. Des modèles mixtes non linéaires ont été utilisés avec succès afin d’estimer l’âge (compté depuis la moelle) du passage bois juvénile-bois adulte pour des pins sylvestres provenant de peuplements à croissance lente. Jusqu’à présent, des modèles de régression segmentés étaient ajustés individuellement à chaque profil de densité du bois de la moelle à l’écorce. Le modèle mixte non linéaire permet de dépasser cette limitation en estimant de manière efficace et cohérente l’âge du point de passage pour l’ensemble de la population échantillonnée. En outre, des variances peuvent être estimées et les impacts des peuplements et des caractéristiques des arbres sur la forme des profils de densité du bois de la moelle à l’écorce peuvent être testés. À cette fin, les profils de densité moyenne de cerne, de densité du bois initial et de densité du bois final de 99 arbres ont été mesurés par exploration microdensitométrique de clichés radiographiques obtenus à partir d’échantillons prélevés dans des disques découpés à 4 mètres de hauteur. L’âge compté depuis la moelle du passage bois juvénile-bois adulte a été identifié à partir de modèles mixtes non linéaires appliqués aux profils de densité du bois final. La nature longitudinale des données a été prise en compte. Le modèle segmenté linéaire quadratique retenu permet d’identifier un âge moyen de passage du bois juvénile au bois adulte de 21,77 ans assorti d’un intervalle de confiance à 5 % de 18,31 à 26,85 ans. Si les impacts des variables “caractéristiques des arbres” et “peuplement” sur l’âge de passage bois juvénile-bois adulte n’ont pas été identifiés comme significatifs, le peuplement est apparu avoir un effet sur la forme des courbes d’évolution de la moelle à l’écorce du caractère considéré

Potentially increased sawmill yield from hardwoods using X-ray computed tomography for knot detection

International audienceAbstractContextOne of the most important wood defects affecting the value yield from European beech (Fagus sylvatica [L.]) logs is knots that are visible on the sawn wood surface. The non-invasive technology of X-ray computed tomography (CT) can be used for the assessment of log internal features, especially the geometry and position of knots before primary breakdown to support the decision of value-optimised log rotation in sawmills.AimsThe objective of this study was to test whether value-optimised log rotation can be performed successfully by using the CT-derived knowledge of internal knottiness for the hardwood species beech.MethodsSize parameters of 670 knots were measured and their position was marked in CT images from 33 logs. The 3D-reconstructed logs were virtually sawn in 12 different rotational angles using the software InnoSIM. This allowed visual grading of the simulated sawn wood and the calculation of product volume and value.ResultsThe results show that if optimal rotation was applied to each single log, both total volume as well as total product value yield could be improved by up to 24 % compared with the average yield of all simulated rotational angles.ConclusionIn this small-scale study, it is demonstrated that CT technology could be used to support the decision about optimal rotational angle of beech logs to maximise volume and value yield