Arthropod communities in fungal fruitbodies are weakly structured by climate and biogeography across European beech forests

Aim The tinder fungus Fomes fomentarius is a pivotal wood decomposer in European beech Fagus sylvatica forests. The fungus, however, has regionally declined due to centuries of logging. To unravel biogeographical drivers of arthropod communities associated with this fungus, we investigated how space, climate and habitat amount structure alpha and beta diversity of arthropod communities in fruitbodies of F. fomentarius. Location Temperate zone of Europe. Taxon Arthropods. Methods We reared arthropods from fruitbodies sampled from 61 sites throughout the range of European beech and identified 13 orders taxonomically or by metabarcoding. We estimated the total number of species occurring in fruitbodies of F. fomentarius in European beech forests using the Chao2 estimator and determined the relative importance of space, climate and habitat amount by hierarchical partitioning for alpha diversity and generalized dissimilarity models for beta diversity. A subset of fungi samples was sequenced for identification of the fungus’ genetic structure. Results The total number of arthropod species occurring in fruitbodies of F. fomentarius across European beech forests was estimated to be 600. Alpha diversity increased with increasing fruitbody biomass; it decreased with increasing longitude, temperature and latitude. Beta diversity was mainly composed by turnover. Patterns of beta diversity were only weakly linked to space and the overall explanatory power was low. We could distinguish two genotypes of F. fomentarius, which showed no spatial structuring. Main conclusion Fomes fomentarius hosts a large number of arthropods in European beech forests. The low biogeographical and climatic structure of the communities suggests that fruitbodies represent a habitat that offers similar conditions across large gradients of climate and space, but are characterized by high local variability in community composition and colonized by species with high dispersal ability. For European beech forests, retention of trees with F. fomentarius and promoting its recolonization where it had declined seems a promising conservation strategy

Where are we now with European forest multi-taxon biodiversity and where can we head to?

The European biodiversity and forest strategies rely on forest sustainable management (SFM) to conserve forest biodiversity. However, current sustainability assessments hardly account for direct biodiversity indicators. We focused on forest multi-taxon biodiversity to: i) gather and map the existing information; ii) identify knowledge and research gaps; iii) discuss its research potential. We established a research network to fit data on species, standing trees, lying deadwood and sampling unit description from 34 local datasets across 3591 sampling units. A total of 8724 species were represented, with the share of common and rare species varying across taxonomic classes: some included many species with several rare ones (e.g., Insecta); others (e.g., Bryopsida) were represented by few common species. Tree-related structural attributes were sampled in a subset of sampling units (2889; 2356; 2309 and 1388 respectively for diameter, height, deadwood and microhabitats). Overall, multitaxon studies are biased towards mature forests and may underrepresent the species related to other developmental phases. European forest compositional categories were all represented, but beech forests were overrepresented as compared to thermophilous and boreal forests. Most sampling units (94%) were referred to a habitat type of conservation concern. Existing information may support European conservation and SFM strategies in: (i) methodological harmonization and coordinated monitoring; (ii) definition and testing of SFM indicators and thresholds; (iii) data-driven assessment of the effects of environmental and management drivers on multi-taxon forest biological and functional diversity, (iv) multi-scale forest monitoring integrating in-situ and remotely sensed information. Forest biodiversity Multi-taxon Sustainable management Biodiversity conservation Forest stand structurepublishedVersio

State Forestry in Belgium since the End of the Eighteenth Century

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Clinical outcome and toxicity after simultaneous integrated boost IMRT in head and neck squamous cell cancer patients.

A simultaneous integrated boost (SIB) intensity modulated radiotherapy (IMRT) in patients with head and neck squamous cell carcinoma (HNSCC) allows to irradiate different target volumes to different dose levels within a single treatment session without increasing the toxicity.info:eu-repo/semantics/publishe

Internal mammary lymph node irradiation contributes to heart dose in breast cancer.

We assessed the impact of internal mammary chain radiotherapy (IMC RT) to the radiation dose received by the heart in terms of heart dose-volume histogram (DVH). Thirty-six consecutive breast cancer patients presenting with indications for IMC RT were enrolled in a prospective study. The IMC was treated by a standard conformal RT technique (50 Gy). For each patient, a cardiac DVH was generated by taking into account the sole contribution of IMC RT. Cardiac HDV were compared according to breast cancer laterality and the type of previous surgical procedure, simple mastectomy or breast conservative therapy (BCT). The contribution of IMC RT to the heart dose was significantly greater for patients with left-sided versus right-sided tumors (13.8% and 12.8% for left-sided tumors versus 3.9% and 4.2% for right-sided tumors in the BCT group and the mastectomy group, respectively; p < 0.0001). There was no statistically significant difference in IMC contribution depending on the initial surgical procedure. IMC RT contributes to cardiac dose for both left-sided and right-sided breast cancers, although the relative contribution is greater in patients with left-sided tumors.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Medical physics principles of radiosurgery.

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Shielding disk position in intra-operative electron radiotherapy (IOERT): A Monte Carlo study

Purpose: In IOERT breast treatments, a shielding disk is frequently used to protect the underlying healthy structures. The disk is usually composed of two materials, a low-Z material intended to be oriented towards the beam and a high-Z material. As tissues are repositioned around the shield before treatment, the disk is no longer visible and its correct alignment with respect to the beam is guaranteed. This paper studies the dosimetric characteristics of four possible clinical positioning scenarios of the shielding disk. A new alignment method for the shielding disk in the beam is introduced. Finally, it suggests a new design for the shielding disk. Methods: As the first step, the IOERT machine “Mobetron 1000” was modeled by using Monte Carlo simulation, tuning the MC model until an excellent match with the measured PDDs and profiles was achieved. Four possible shielding disk positioning scenarios were considered, determining the dosimetric impact. Furthermore, in our center, to prevent beam misalignment, we have developed a shielding disk equipped with guiding rods. Having ascertained a correct alignment between the disk and the beam, we can propose a new internal design of the shielding disk that can improve the dose distribution with a better coverage of the treated area. Results: All MC simulations were performed with a 12 MeV beam, the maximum energy of Mobetron 1000 and a 5.5 cm diameter flat tip applicator, this applicator being the most clinically used. The simulations were compared with measurements performed in a water phantom and showed good results within 2.2% of root mean square difference (RMSD). The misplacement positions of the shielding disk have dosimetric impacts in the treatment volume and a small translation could have a significant influence on healthy tissues. The D-scenario is the worst which could happens when the shielding disk is flipped upside down, giving up to 144% dose instead of 90% at the surface of the Pb/Al shielding disk. A new shielding design used, together with our alignment tool, is able to give a more homogeneous dose in the target area. Conclusions: The accuracy of shielding disk position can still be problematic in IOERT dosimetry. Any method that can ascertain the good alignment between the shielding disk and the beam is beneficial for the dose distribution and is a prerequisite for an optimized shield internal design that could improve the coverage of the treated area and the protection of healthy tissues.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Monte Carlo dose calculations of shielding disks with different material combinations in intraoperative electron radiation therapy (IOERT)

Shielding disks play an important role in intraoperative electron radiation therapy, and different designs are currently used in clinical practice. This paper investigates the dosimetric impact of the shielding disk used during intraoperative electron radiation therapy (IOERT).info:eu-repo/semantics/publishe

3D Monte Carlo dosimetry of intraoperative electron radiation therapy (IOERT)

Purpose: This paper studies the feasibility of using Monte Carlo (MC) for treatment planning of intraoperative electron radiation therapy (IOERT) procedure to get 3D dose by using patient's CT images. Methods: The IOERT treatment planning was performed using the following successive steps: I) The Mobetron 1000® machine was modelled with the EGSnrc MC codes. II) The MC model was validated with measurements of percentage depth doses and profiles for three energies (12, 9, 6) MeV. III) CT images were imported as DICOM files. IV) Contouring of the planning target volume (PTV) and the organs at risk was done by the radiation oncologist. V) The medical physicist with the radiation oncologist, had chosen the same parameters of IOERT procedures like energy, applicator (type, size) and using or not bolus. VI) Finally, dose calculation and analysis of 3D maps was carried out. Results: The tuning process of the MC model provides good results, as the maximum value of the root mean square deviation (RMSD) was less than 3% between the MC simulated PDDs and the measured PDDs. The contouring and dose analysis review were easy to conduct for the classical treatment planning system. The radiation oncologist had many tools for dose analysis such as DVH and color wash for all the slides. Summation of the 3D dose of IOERT with other radiotherapy plans is possible and helpful for total dose estimation. Archiving and documentation is as good as treatment planning system (TPS). Conclusions: The method displayed in this paper provides a step forward for IOERT Dosimetry and allows to obtain accurate dosimetry of treated volumes.SCOPUS: ar.jinfo:eu-repo/semantics/publishe