Drought increases Norway spruce susceptibility to the Eurasian spruce bark beetle and its associated fungi.

Drought affects the complex interactions between Norway spruce, the bark beetle Ips typographus and associated microorganisms. We investigated the interplay of tree water status, defense and carbohydrate reserves with the incidence of bark beetle attack and infection of associated fungi in mature spruce trees. We installed roofs to induce a 2-yr moderate drought in a managed spruce stand to examine a maximum of 10 roof and 10 control trees for resin flow (RF), predawn twig water potentials, terpene, phenolic and carbohydrate bark concentrations, and bark beetle borings in field bioassays before and after inoculation with Endoconidiophora polonica and Grosmannia penicillata. Drought-stressed trees showed more attacks and significantly longer fungal lesions than controls, but maintained terpene resin defenses at predrought levels. Reduced RF and lower mono- and diterpene, but not phenolic concentrations were linked with increased host selection. Bark beetle attack and fungi stimulated chemical defenses, yet G. penicillata reduced phenolic and carbohydrate contents. Chemical defenses did not decrease under mild, prolonged drought in our simulated small-scale biotic infestations. However, during natural mass attacks, reductions in carbon fixation under drought, in combination with fungal consumption of carbohydrates, may deplete tree defenses and facilitate colonization by I. typographus.

Insights into the Value of Lyso-Gb1 as a Predictive Biomarker in Treatment-Naïve Patients with Gaucher Disease Type 1 in the LYSO-PROOF Study.

Gaucher disease (GD) is a rare autosomal recessive disorder arising from bi-allelic variants in the GBA1 gene, encoding glucocerebrosidase. Deficiency of this enzyme leads to progressive accumulation of the sphingolipid glucosylsphingosine (lyso-Gb1). The international, multicenter, observational "Lyso-Gb1 as a Long-term Prognostic Biomarker in Gaucher Disease"-LYSO-PROOF study succeeded in enrolling a cohort of 160 treatment-naïve GD patients from diverse geographic regions and evaluated the potential of lyso-Gb1 as a specific biomarker for GD. Using genotypes based on established classifications for clinical presentation, patients were stratified into type 1 GD (n = 114) and further subdivided into mild (n = 66) and severe type 1 GD (n = 48). Due to having previously unreported genotypes, 46 patients could not be classified. Though lyso-Gb1 values at enrollment were widely distributed, they displayed a moderate and statistically highly significant correlation with disease severity measured by the GD-DS3 scoring system in all GD patients (r = 0.602, p < 0.0001). These findings support the utility of lyso-Gb1 as a sensitive biomarker for GD and indicate that it could help to predict the clinical course of patients with undescribed genotypes to improve personalized care in the future.

Psychological Aspects of Infertility - Results from an Actor-Partner Interdependence Analysis.

Introduction For some patients, undergoing medical treatment for infertility is a cause of major emotional stress which the couple needs to deal with together; it can be said that infertility is a shared stressor. From the literature it is known that a subjectively perceived sense of self-efficacy supports the patient's ability to cope adaptively with an illness. As the basis for this study, we assumed that high levels of self-efficacy are associated with low psychological risk scores (e.g., for anxiety or depressiveness), both in the patient themselves and in their partner. Accordingly, in infertility patients, targeted support to promote helpful self-efficacy expectations could represent a new counselling strategy that could enable psychologically vulnerable patients to better cope with the treatment procedure and treatment failures of medically assisted reproduction, making these patients less at risk with regard to psychosocial factors. Methods 721 women and men attending five fertility centers in Germany (Heidelberg, Berlin), Austria (Innsbruck), and Switzerland (St. Gallen, Basel) completed the SCREENIVF-R questionnaire to identify psychological risk factors for amplified emotional problems, as well as the ISE scale to measure self-efficacy. Using paired t-tests and the actor-partner interdependence model, we analyzed the data of 320 couples. Results Considering the study participants as couples, women had a higher risk score than men for four out of five risk factors (depressiveness, anxiety, lack of acceptance, helplessness). In all of the risk areas, it was possible to identify a protective effect from self-efficacy on the patient's own risk factors (actor effect). There was a negative correlation between the men's self-efficacy level and the women's feelings of depressiveness and helplessness (partner effect, man → woman). The women's self-efficacy levels had a positive correlation with acceptance and access to social support in the men (partner effect, woman → man). Conclusion Because infertility is generally something that a couple has to deal with together, future studies should focus on couples as the unit of analysis instead of just analyzing the men and women separately. In addition, couples therapy should be the gold standard in psychotherapy for infertility patients.

Analysing medical predictors for the outcome of infertility treatment: a 5-year follow-up survey.

PURPOSE: For many couples, bearing children is a common life goal; however it cannot always be fulfilled. Undergoing infertility treatment does not always guarantee pregnancies and live births. Couples experience miscarriages and even discontinue infertility treatment. Significant medical predictors for the outcome of infertility treatment have yet to be fully identified. METHODS: To further our understanding, a cross-sectional 5-year follow-up survey was undertaken, in which 95 women and 82 men that have been treated at the Women's Hospital of Heidelberg University participated. Binary logistic regressions, parametric and non-parametric methods were used for our sample to determine the relevance of biological (infertility diagnoses, maternal and paternal age) and lifestyle factors (smoking, drinking, over- and underweight) on the outcome of infertility treatment (clinical pregnancy, live birth, miscarriage, dropout rate). In addition, chi-square tests were used to examine differences in the outcome depending on the number of risk factors being present. RESULTS: In the binary logistic regression models for clinical pregnancies, live births and drop outs were statistically significant only for the maternal age, whereas the maternal and paternal BMI, smoking, infertility diagnoses and infections showed no significant predicting effect on any of the outcome variables. A correlation between the number of risk factors and the outcome of infertility treatment could not be excluded. CONCLUSION: The results confirm that maternal age has an effect on infertility treatment, whereas the relevance of other possible medical predictors remains unclear. Further large-scale studies should be considered to increase our knowledge on their predictive power.

Partners matter: The psychosocial well-being of couples when dealing with endometriosis.

BACKGROUND: Endometriosis is often associated with severe dysmenorrhea, pelvic pain and dyspareunia and has a high impact on daily life as well as sexuality. Quality of partnership positively influences the course of various diseases and ability to cope with emotional and physical distress. However, studies focusing on the male partners of endometriosis patients are rare, and even less is known about the reciprocal relationship in these couples. Therefore, this study aims to explore the interrelations in couples with endometriosis in matters of psychological distress, sexual and partnership satisfaction and social support. METHODS: The cross-sectional study was conducted in two university-affiliated fertility centres in Germany and Austria with n = 104 female/male couples affected by endometriosis. Participants completed a questionnaire regarding endometriosis, partnership, sexuality, stress, anxiety, depression and social support. Both women and men were asked about the impact of women's endometriosis-related pain (IEP) on their everyday life (e.g. leisure time). Data were analysed using the Actor-Partner-Interdependence Model. RESULTS: Significant partner effects were evident: High depression, anxiety and stress scores in women were associated with a higher IEP in men (all p ≤ 0.01), reciprocally high stress and depression scores in men were correlated with a higher IEP in women (all p ≤ 0.05). Less sexual satisfaction in women was associated with a higher IEP in men (p = 0.040). There was a significant reciprocal association between the perceived lack of understanding from the social environment and a higher IEP, for both women (p = 0.022) and men (p = 0.027). CONCLUSIONS: The male partner should be taken into account when counselling or treating women with endometriosis. Our study shows a high interdependence and reciprocal influence from both partners-positively and negatively-concerning psychological distress and sexual satisfaction. Furthermore, there ought to be more awareness for the psychosocial impact of endometriosis, especially in regard to social support and understanding. Talking about and improving sexual satisfaction as well as enhancing stress reducing techniques may hold great benefits for dealing with endometriosis. Registration number The study is registered with the German Clinical Trials Register (DRKS), number DRKS00014362.

Physiological and anatomical responses to drought stress differ between two larch species and their hybrid.

KEY MESSAGE: Hybrid saplings were more reactive to soil water deficit than Japanese and European larch. European larch had hydraulically safer wood and anisohydric behavior, Japanese and hybrid larch showed isohydric strategy. ABSTRACT: Deciduous larch species could be an alternative to evergreen conifers in reforestation, but little is known about drought sensitivity of their saplings. The effect of an experimental drought on hydraulics and quantitative wood anatomy was tested on saplings of European larch (EL, Larix decidua), Japanese larch (JL, Larix kaempferi) and their hybrid (HL). Across species, biomass, transpiration rate and relative water content were higher in controls than in drought stressed trees, but transpiration efficiency was lower. JL had the highest transpiration efficiency under drought, and EL the lowest, coinciding with slower growth of EL. Wood of EL formed before drought was hydraulically safer as shown by higher wall/lumen ratio and lower pit cavity area. EL neither had a significant increase in transpiration efficiency nor a reduction in transpiration rate under drought, suggesting that the stomata remained open under soil water deficit. HL saplings were the most reactive to water shortage, indicated by intra-annual density fluctuations and a decrease in relative water content of the sapwood. Significant reduction in transpiration by HL suggested a higher stomatal sensitivity, while the same leaf surface area was maintained and radial growth was still similar to its best parent, the JL. The latter showed a significantly lower leaf surface area under drought than controls. EL, with its hydraulically safer wood, followed an anisohydric behavior, while JL and HL revealed an isohydric strategy. Altogether, our results suggest species dependent acclimations to drought stress, whereby HL followed the strategy of JL rather than that of EL. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00468-021-02129-4.

Container volume affects drought experiments in grapevines: Insights on xylem anatomy and time of dehydration.

Plant stress experiments are commonly performed with plants grown in containers to better control environmental conditions. Nevertheless, the container can constrain plant growth and development, and this confounding effect is generally ignored, particularly in studies on woody species. Here, we evaluate the effect of the container volume in drought experiments using grapevine as a model plant. Grapevines grown in small (7 L, S) or large (20 L, L) containers were subjected to drought stress and rewatering treatments. We monitored plant stomatal conductance (gs ), midday stem water potential (Ψs ), and photosynthetic rate (AN ) throughout the experiment. The effect of the container volume on the stem and petiole xylem anatomy, as well as on the total leaf area (LA), was assessed before drought imposition. The results showed that LA did not differ between plants in L or S containers, but S vines exhibited a higher theoretical hydraulic conductance at the petiole level. Under drought L and S similarly reduced gs and AN , but plants in S containers reached lower Ψs than those in L. Nevertheless, upon rewatering droughted plants in S containers exhibited a faster stomata re-opening than those in L, probably as a consequence of the differences in the stress degree experienced and the biochemical adjustment at the leaf level. Therefore, a suitable experimental design should consider the container volume used in relation to the desired traits to be studied for unbiased results.

Lignin Quantification of Papyri by TGA-Not a Good Idea.

Papyri belong to the oldest writing grounds in history. Their conservation is of the highest importance in preserving our cultural heritage, which is best achieved based on an extensive knowledge of the materials' constituents to choose a tailored conservation approach. Thermogravimetric Analysis (TGA) has been widely employed to quantify cellulose and lignin in papyrus sheets, yielding reported lignin contents of 25% to 40%. In this work, the TGA method conventionally used for papyrus samples was repeated and compared to other lignin determination approaches (Klason-lignin and acetyl bromide-soluble lignin). TGA can lead to a large overestimation of the lignin content of commercial papyrus sheets (~27%) compared to the other methods (~5%). A similar overestimation of the lignin content was found for the pith and rind of the native papyrus plant. We concluded that the TGA method should, therefore, not be used for lignin quantification.

Factors Influencing Success Rate of Intracytoplasmic Sperm Injection with Azoospermic Male Patients.

Introduction Azoospermia affects about 1% of men, of whom up to 15% inquire about infertility treatment. Information about predictive factors for these couples is very limited. Patients, Materials and Methods We performed a retrospective analysis of the clinical records of 118 cycles of intracytoplasmic sperm injection treatment after testicular sperm extraction for male azoospermia carried out between January 2008 and October 2015. Of those, 66 were first, 35 second, and 17 third cycles. Statistical significance was set at p < 0.05. Predictive factors for successful pregnancy were evaluated and included male/female age, male/female body mass index, male/female nicotine use, and histological results of testes biopsies. Results Embryo quality and the number of embryos transferred were positively associated with pregnancy success (p = 0.003). Males whose partners conceived had a significantly lower body mass index than those whose partners did not conceive (p = 0.023). Neither female weight nor age nor smoking status of the male or female were significant factors. In cases with tubular atrophy ≥ SIGG grade 4 the chance of pregnancy was poor, irrespective of the existence of mature sperm and the number of cycles performed. Conclusion Overweight male patients should be advised about weight reduction prior to treatment, and counseling about success rates should include histological and sperm-positive biopsy results.

Major central nervous system complications after allogeneic stem cell transplantation: A large retrospective study on 888 consecutive adult patients.

OBJECTIVES: Major complications affecting the central nervous system (CNS) present a challenge after allogeneic stem cell transplantation (allo-SCT). METHODS: Incidence, risk factors, and outcome were retrospectively analyzed in 888 patients in a monocentric study. RESULTS: Cumulative incidence (CI) of major CNS complications at 1 year was 14.8% (95%CI 12.3%-17.2%). Median follow-up is 11 months. CNS complications were documented in 132 patients: in 36 cases, classified metabolic; 26, drug-related neurotoxicity (14 attributed to cyclosporine A, 4 to antilymphocyte globulin); 11, cerebrovascular (ischemic n = 8, bleeding n = 3); 9, infections; 9, psychiatric; and 9, malignant. The cause of CNS symptoms remained unclear for 37 patients (28%). Multivariate analysis demonstrated an association of CNS complication with patient age (P < .001). The estimated OS of patients with any CNS complication was significantly lower than in patients without neurological complications (P < .001), and the CI of non-relapse mortality (NRM) was higher for patients with CNS complication (P < .001). A significant negative impact on survival can only be demonstrated for metabolic CNS complications and CNS infections (NRM, P < .0001 and P = .0003, respectively), and relapse (P < .0001). CONCLUSION: CNS complications after allo-SCT are frequent events with a major contribution to morbidity and mortality. In particular, the situations of unclear neurological complications need to be clarified by intensive research.

Predictors for the Early Termination of a Psychological Intervention During Treatment with Assisted Reproductive Technologies.

Introduction Assisted reproductive technologies are typically perceived by couples as being an emotional burden. The objective of the study "Positive Ausrichtung bei unerfülltem Kinderwunsch" [Positive adjustment in infertility] (PACI) is to examine the efficacy and acceptance of a smartphone-supported psychosocial intervention during infertility treatment. In this investigation, the early drop-out of study subjects from the study is of primary interest. The objective of the investigation was to find predictors for ending a psychological intervention prematurely. Materials and Methods There are data available from an eight-month randomised, controlled study in which 141 patients and their partners participated. Sociodemographic and fertility-related data were collected at the start of the study. The couples received the ScreenIVF questionnaire at two points in time. As part of a post-evaluation, a survey was conducted on the efficacy of the psychological online intervention. To analyse the data, a dyadic data structure was used in order to determine connections within the study subject couples between the selected stress indicators and the drop-out. In addition, a "risk score" as a possible predictor for the drop-out was tested. Results The descriptive observation of the sample indicates in this interim assessment that the study subjects recruited are less stressed patient couples. Actor-partner interdependence models indicate statistically significant connections between the stress indicators of anxiety, little social support and helplessness and an early drop-out. Conclusions The statistically significant effects found in this study with regard to the stress indicators in connection with drop-outs from psychosocial intervention studies indicate that it is advisable to continue to seek measures for people undergoing stressful medical treatments in order to motivate and support them and thus optimally utilise the opportunities of a medical treatment. The number of patients who endure their ART treatment may also increase as a result, which could lead in turn to increased patient satisfaction over the long term (and thus possibly to higher pregnancy rates).

Using the CODIT model to explain secondary metabolites of xylem in defence systems of temperate trees against decay fungi.

BACKGROUND: In trees, secondary metabolites (SMs) are essential for determining the effectiveness of defence systems against fungi and why defences are sometimes breached. Using the CODIT model (Compartmentalization of Damage/Dysfunction in Trees), we explain defence processes at the cellular level. CODIT is a highly compartmented defence system that relies on the signalling, synthesis and transport of defence compounds through a three-dimensional lattice of parenchyma against the spread of decay fungi in xylem. SCOPE: The model conceptualizes 'walls' that are pre-formed, formed during and formed after wounding events. For sapwood, SMs range in molecular size, which directly affects performance and the response times in which they can be produced. When triggered, high-molecular weight SMs such as suberin and lignin are synthesized slowly (phytoalexins), but can also be in place at the time of wounding (phytoanticipins). In contrast, low-molecular weight phenolic compounds such as flavonoids can be manufactured de novo (phytoalexins) rapidly in response to fungal colonization. De novo production of SMs can be regulated in response to fungal pathogenicity levels. The protective nature of heartwood is partly based on the level of accumulated antimicrobial SMs (phytoanticipins) during the transitionary stage into a normally dead substance. Effectiveness against fungal colonization in heartwood is largely determined by the genetics of the host. CONCLUSION: Here we review recent advances in our understanding of the role of SMs in trees in the context of CODIT, with emphasis on the relationship between defence, carbohydrate availability and the hydraulic system.We also raise the limitations of the CODIT model and suggest its modification, encompassing other defence theory concepts. We envisage the development of a new defence system that is modular based and incorporates all components (and organs) of the tree from micro- to macro-scales.

Drought-induced dieback of Pinus nigra: a tale of hydraulic failure and carbon starvation.

Ongoing climate change is apparently increasing tree mortality rates, and understanding mechanisms of drought-induced tree decline can improve mortality projections. Differential drought impact on conspecific individuals within a population has been reported, but no clear mechanistic explanation for this pattern has emerged. Following a severe drought (summer 2012), we monitored over a 3-year period healthy (H) and declining (D) Pinus nigra trees co-occurring in a karstic woodland to highlight eventual individual-specific physiological differences underlying differential canopy dieback. We investigated differences in water and carbon metabolism, and xylem anatomy as a function of crown health status, as well as eventual genotypic basis of contrasting drought responses. H and D trees exploited the same water pools and relied on similar hydraulic strategies to cope with drought stress. Genetic analyses did not highlight differences between groups in terms of geographical provenance. Hydraulic and anatomical analyses showed conflicting results. The hydraulic tracheid diameter and theoretical hydraulic conductivity were similar, but D trees were characterized by lower water transport efficiency, greater vulnerability to xylem conduit implosion and reduced carbohydrate stores. Our results suggest that extreme drought events can have different impacts on conspecific individuals, with differential vulnerability to xylem embolism likely playing a major role in setting the fate of trees under climate change.

The potential of Mid-Infrared spectroscopy for prediction of wood density and vulnerability to embolism in woody angiosperms.

Xylem resistance to embolism formation determines the species-specific drought tolerance and the survival prospects of plants under extreme climatic conditions. Fourier Transform-Infrared (FTIR) spectroscopy is a cost-effective and rapid analytical tool with potential beyond its current use in plant physiology. We tested the use of FTIR spectroscopy as a method for estimating wood density (WD) and xylem resistance to embolism formation (P50) in 24 angiosperm species. Higher WD was associated with more negative P50 (r2 = 0.41). Partial least squares regression was applied to establish models of FTIR spectra and the reference data. They showed a high predictive quality for WD (r2 = 0.73), whereas the prediction of P50 was weaker (r2 = 0.49). By including WD in the model as an additional factor influencing P50, its predictive power significantly increased (r2 = 0.59). The spectral range in the model elaboration has been also narrowed (bands of lignin, cellulose, hemicellulose), but this did not influence the model descriptors, suggesting that for P50 prediction broad spectral range is more informative than narrow band regions reflecting main wood constituents. In conclusion, FTIR spectroscopy associated with WD measurements has proven to be a promising alternative to traditional methods for screening of individual- or species-specific resistance to embolism in angiosperms.

Prediction of hydraulic conductivity loss from relative water loss: new insights into water storage of tree stems and branches.

More frequently occurring, drought waves call for a deeper understanding of tree hydraulics and fast and easily applicable methods to measure drought stress. The aim of this study was to establish empirical relationships between the percent loss of hydraulic conductivity (PLC) and the relative water loss (RWL) in woody stem axes with different P50 , i.e. the water potential (Ψ) that causes 50% conductivity loss. Branches and saplings of temperate conifer (Picea abies, Larix decidua) and angiosperm species (Acer campestre, Fagus sylvatica, Populus x canescens, Populus tremula, Sorbus torminalis) and trunk wood of mature P. abies trees were analyzed. P50 was calculated from hydraulic measurements following bench top dehydration or air injection. RWL and PLC were fitted by linear, quadratic or cubic equations. Species- or age-specific RWLs at P50 varied between 10 and 25% and P88 , the Ψ that causes 88% conductivity loss, between 18 and 44%. P50 was predicted from the relationship between Ψ and the RWL. The predictive quality for P50 across species was almost 1:1 (r2 = 0.99). The approach presented allows thus reliable and fast prediction of PLC from RWL. Branches and saplings with high hydraulic vulnerability tended to have lower RWLs at P50 and at P88 . The results are discussed with regard to the different water storage capacities in sapwood and survival strategies under drought stress. Potential applications are screening trees for drought sensitivity and a fast interpretation of diurnal, seasonal or drought induced changes in xylem water content upon their impact on conductivity loss.

Pre-Pregnancy Levels of Peripheral Natural Killer Cells as Markers for Immunomodulatory Treatment in Patients with Recurrent Miscarriage.

Immunological risk factors in patients with recurrent miscarriage (RM) are discussed controversially. Abnormalities of natural killer cells (NK) have been described in RM patients. Lipid infusions are known to modulate lymphocyte subsets. The aim of this study was to identify immune parameters that predict success of treatment with lipid infusions in RM patients with elevated NK. In sum, n = 341 couples with RM were screened for established risk factors and peripheral lymphocyte subpopulations as well as uterine NK cells. We identified n = 136 patients with ≥ 2 consecutive RM and elevated NK. So far, n = 40 RM patients with NK disorders were treated with lipid infusions starting at positive pregnancy test, every 2 weeks until 12 + 0 weeks of gestation (GW) or miscarriage. The pre-pregnancy immune diagnostics in idiopathic RM (iRM) patients with ongoing pregnancy were compared to the group with miscarriages and healthy controls (n = 15). Pre-pregnancy immune diagnostics differed significantly between the groups, with significant higher levels of peripheral NK (% and /µL) in iRM patients who miscarried again compared to controls (p = 0.0035 and p = 0.0019). Furthermore, iRM patients show lower percentages of CD3+ lymphocytes than healthy controls (p = 0.0049). In n = 22/40 (55%) patients, pregnancy is ongoing >12 + 0 GW. RM patients with very high pre-pregnancy peripheral NK (pNK) lymphocytes might not benefit from lipid infusions. Pre-pregnancy immunomodulatory treatment in RM patients might be helpful to lower pNK levels and establish an immune environment which is supportive for fetal development.

Wood traits related to size and life history of trees in a Panamanian rainforest.

Wood structure differs widely among tree species and species with faster growth, higher mortality and larger maximum size have been reported to have fewer but larger vessels and higher hydraulic conductivity (Kh). However, previous studies compiled data from various sources, often failed to control tree size and rarely controlled variation in other traits. We measured wood density, tree size and vessel traits for 325 species from a wet forest in Panama, and compared wood and leaf traits to demographic traits using species-level data and phylogenetically independent contrasts. Wood traits showed strong phylogenetic signal whereas pairwise relationships between traits were mostly phylogenetically independent. Trees with larger vessels had a lower fraction of the cross-sectional area occupied by vessel lumina, suggesting that the hydraulic efficiency of large vessels permits trees to dedicate a larger proportion of the wood to functions other than water transport. Vessel traits were more strongly correlated with the size of individual trees than with maximal size of a species. When individual tree size was included in models, Kh scaled positively with maximal size and was the best predictor for both diameter and biomass growth rates, but was unrelated to mortality.

Novel Hydraulic Vulnerability Proxies for a Boreal Conifer Species Reveal That Opportunists May Have Lower Survival Prospects under Extreme Climatic Events.

Top dieback in 40-60 years old forest stands of Norway spruce [Picea abies (L.) Karst.] in southern Norway is supposed to be associated with climatic extremes. Our intention was to learn more about the processes related to top dieback and in particular about the plasticity of possible predisposing factors. We aimed at (i) developing proxies for P 50 based on anatomical data assessed by SilviScan technology and (ii) testing these proxies for their plasticity regarding climate, in order to (iii) analyze annual variations of hydraulic proxies of healthy looking trees and trees with top dieback upon their impact on tree survival. At two sites we selected 10 tree pairs, i.e., one healthy looking tree and one tree with visual signs of dieback such as dry tops, needle shortening and needle yellowing (n = 40 trees). Vulnerability to cavitation (P 50) of the main trunk was assessed in a selected sample set (n = 19) and we thereafter applied SilviScan technology to measure cell dimensions (lumen (b) and cell wall thickness (t)) in these specimen and in all 40 trees in tree rings formed between 1990 and 2010. In a first analysis step, we searched for anatomical proxies for P 50. The set of potential proxies included hydraulic lumen diameters and wall reinforcement parameters based on mean, radial, and tangential tracheid diameters. The conduit wall reinforcement based on tangential hydraulic lumen diameters ((t/b ht)(2)) was the best estimate for P 50. It was thus possible to relate climatic extremes to the potential vulnerability of single annual rings. Trees with top dieback had significantly lower (t/b ht)(2) and wider tangential (hydraulic) lumen diameters some years before a period of water deficit (2005-2006). Radial (hydraulic) lumen diameters showed however no significant differences between both tree groups. (t/b ht)(2) was influenced by annual climate variability; strongest correlations were found with precipitation in September of the previous growing season: high precipitation in previous September resulted in more vulnerable annual rings in the next season. The results are discussed with respect to an "opportunistic behavior" and genetic predisposition to drought sensitivity.