High preseason temperature variability drives convergence of xylem phenology in the Northern Hemisphere conifers.

Wood growth is key to understanding the feedback of forest ecosystems to the ongoing climate warming. An increase in spatial synchrony (i.e., coincident changes in distant populations) of spring phenology is one of the most prominent climate responses of forest trees. However, whether temperature variability contributes to an increase in the spatial synchrony of spring phenology and its underlying mechanisms remains largely unknown. Here, we analyzed an extensive dataset of xylem phenology observations of 20 conifer species from 75 sites over the Northern Hemisphere. Along the gradient of increase in temperature variability in the 75 sites, we observed a convergence in the onset of cell enlargement roughly toward the 5th of June, with a convergence in the onset of cell wall thickening toward the summer solstice. The increase in rainfall since the 5th of June is favorable for cell division and expansion, and as the most hours of sunlight are received around the summer solstice, it allows the optimization of carbon assimilation for cell wall thickening. Hence, the convergences can be considered as the result of matching xylem phenological activities to favorable conditions in regions with high temperature variability. Yet, forest trees relying on such consistent seasonal cues for xylem growth could constrain their ability to respond to climate warming, with consequences for the potential growing season length and, ultimately, forest productivity and survival in the future.

Predicting 60-Day Mortality in a Home-Care Service: Development of a New Inter-RAI 49-Frailty Index in Patients with Chronic Disease and without a Cancer Diagnosis.

OBJECTIVE: Frailty Index (FI) is used to define the level of frailty in various clinical settings. Fifteen- and 26-item FIs have been demonstrated to predict 1-year mortality and intensity of care in home care (HC) and palliative home care (PHC). The objective of this study was to develop a new FI to predict the 60-day risk of death or transition to a PHC service after the initiation of an HC service in patients with chronic disease and without a cancer diagnosis. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Patients 18 years and older followed in an HC service of a "Frailty Department-Local Palliative Care Network" from January 1, 2017, to October 31, 2021. METHODS: A 49-item FI (FI-49) was developed selecting variables within the standardized international Residential Assessment Instrument assessments (interRAI-HC) and compared to existing FIs with 15 and 26 variables. RESULTS: A total of 2099 patients were included in the study with a median age of 80.0 years (IQR: 72.0-86.0) and a predominantly female population (62.4%). Among these patients, 8% died or were transferred to PHC within the 60-day follow-up. The FI-49 demonstrated a higher ability to predict 60-day mortality (C index 0.8165, 95% CI 0.7848-0.8481) compared to the 26- and 15-item FI. An FI-49 cutoff of 0.33 was also selected to provide clinicians with a more practical approach (C-index of 0.7044, 95% CI 0.6796-0.7292). CONCLUSION AND IMPLICATION: The FI-49 is a good predictor of short-term mortality or transition to palliative care among older patients referred to an HC service. The automatic calculation of this tool could facilitate more appropriate care planning and the correct allocation of healthcare resources, especially considering the rapid ageing of the population.

A critical thermal transition driving spring phenology of Northern Hemisphere conifers.

Despite growing interest in predicting plant phenological shifts, advanced spring phenology by global climate change remains debated. Evidence documenting either small or large advancement of spring phenology to rising temperature over the spatio-temporal scales implies a potential existence of a thermal threshold in the responses of forests to global warming. We collected a unique data set of xylem cell-wall-thickening onset dates in 20 coniferous species covering a broad mean annual temperature (MAT) gradient (-3.05 to 22.9°C) across the Northern Hemisphere (latitudes 23°-66° N). Along the MAT gradient, we identified a threshold temperature (using segmented regression) of 4.9 ± 1.1°C, above which the response of xylem phenology to rising temperatures significantly decline. This threshold separates the Northern Hemisphere conifers into cold and warm thermal niches, with MAT and spring forcing being the primary drivers for the onset dates (estimated by linear and Bayesian mixed-effect models), respectively. The identified thermal threshold should be integrated into the Earth-System-Models for a better understanding of spring phenology in response to global warming and an improved prediction of global climate-carbon feedbacks.

White rot fungal impact on the evolution of simple phenols during decay of silver fir wood by UHPLC-HQOMS.

INTRODUCTION: Silver fir (Abies alba Mill.) is one of the most valuable conifer wood species in Europe. Among the main opportunistic pathogens that cause root and butt rot on silver fir are Armillaria ostoyae and Heterobasidion abietinum. Due to the different enzymatic pools of these wood-decay fungi, different strategies in metabolizing the phenols were available. OBJECTIVE: This work explores the changes in phenolic compounds during silver fir wood degradation. METHODOLOGY: Phenols were analyzed before and after fungus inoculation in silver fir macerated wood after 2, 4 and 6 months. All samples were analyzed using high-performance liquid chromatography coupled to a hybrid quadrupole-orbitrap mass spectrometer. RESULTS: Thirteen compounds, including simple phenols, alkylphenyl alcohols, hydroxybenzoketones, hydroxycinnamaldehydes, hydroxybenzaldehydes, hydroxyphenylacetic acids, hydroxycinnamic acids, hydroxybenzoic acids and hydroxycoumarins, were detected. Pyrocatechol, coniferyl alcohol, acetovanillone, vanillin, benzoic acid, 4-hydroxybenzoic acid and vanillic acid contents decreased during the degradation process. Methyl vanillate, ferulic acid and p-coumaric were initially produced and then degraded. Scopoletin was accumulated. Pyrocatechol, acetovanillone and methyl vanillate were found for the first time in both degrading and non-degrading wood of silver fir. CONCLUSIONS: Despite differences in the enzymatic pool, both fungi caused a significant decrease in the amounts of phenolic compounds with the accumulation of the only scopoletin. Principal component analysis revealed an initial differentiation between the degradation activity of the two fungal species during degradation, but similar phenolic contents at the end of wood degradation.

Conhecimento da população acerca dos benefícios da imunização infantil: uma revisão integrativa / Conocimiento de la población sobre los bene cios de la inmunización infantil: una revisión integrativa / Population knowledge about the bene ts of child immunization: an integrative review

Analisar através de evidências cientificas, o nível de conhecimento da população acerca dos benefícios da imunização infantil. Método: Trata-se de uma revisão integrativa da literatura acerca dos benefícios da imunização infantil, publicada nos últimos 7 anos, dentro das seguintes bases de dados: SciELO, Science direct, biblioteca virtual em Saúde e PubMed. Resultados: Foram analisados 495 artigos, dos quais 7 artigos foram selecionados para esta revisão integrativa, a qual foi realizada de maio a junho de 2020. Foi possível perceber que há uma porcentagem ainda grande da população mundial que opta pela não imunização de suas crianças, onde a grande maioria se dá em países subdesenvolvidos, por falta de visibilidade da mídia e baixa escolaridade, principalmente. Conclusão: Campanhas de vacinação e esclarecimento sobre vacinas devem ser realizadas de forma sistemática.(AU)

Objective: To analyze through scientific evidence, the population's level of knowledge about the benefits of childhood immunization. Method: This is an integrative literature review on the benefits of childhood immunization, published inM the last 7 years, in the following databases: SciELO, Science direct, Virtual Health Library and PubMed. Results: 495 articles were analyzed, of which 7 articles were selected for this integrative review. It was possible to notice that there is a still large percentage of the world population that chooses not to immunize their children, where the vast majority takes place in underdeveloped countries, mainly due to lack of media visibility and low education level. Conclusion: Vaccination campaigns and information about vaccines must be carried out systematically.(AU)

Objetivo: Analizar através de evidencia cientifica, el nível de conocimento de la población sobre los benefícios de la inmunización infantil. Método: Se trata de una revisión bibliográfica sobre los benefícios de la imunización infantil, publicada en los últimos 7 años, dentro de las seguientes bases de datos: SciELO, Science direct, Virtual Health Library e PubMed. Resultados: Se analizaron 495 artículos, de los cuales se seleccionaron 7 artículos para esta revisión integradora. Se pudo notar que todavia hay um gran porcentaje de la población mundial que opta por no vacunar a sus hijos, donde la gran mayoría se da em países subdesarrollados, debido a la falta de visibilidad en los medios y la baja educación, especialmente. Conclusión: Las campañas de vacunación y la información sobre vacunas deben realizarse de forma sistemática.(AU)

European primary forest database v2.0.

Primary forests, defined here as forests where the signs of human impacts, if any, are strongly blurred due to decades without forest management, are scarce in Europe and continue to disappear. Despite these losses, we know little about where these forests occur. Here, we present a comprehensive geodatabase and map of Europe's known primary forests. Our geodatabase harmonizes 48 different, mostly field-based datasets of primary forests, and contains 18,411 individual patches (41.1 Mha) spread across 33 countries. When available, we provide information on each patch (name, location, naturalness, extent and dominant tree species) and the surrounding landscape (biogeographical regions, protection status, potential natural vegetation, current forest extent). Using Landsat satellite-image time series (1985-2018) we checked each patch for possible disturbance events since primary forests were identified, resulting in 94% of patches free of significant disturbances in the last 30 years. Although knowledge gaps remain, ours is the most comprehensive dataset on primary forests in Europe, and will be useful for ecological studies, and conservation planning to safeguard these unique forests.

Avaliação do pé nos portadores de diabetes melitus / Evaluation of the foot in melitus diabetes

Objetivo: Avaliar o pé dos indivíduos portadores de Diabetes Melitus atendidos na atenção básica de um município do interior paulista. Método: Trata-se de um estudo quantitativo. Foram examinados 100 pés dos portadores de diabetes, no período de 1 a 31 de julho de 2019, aos usuários dos serviços de saúde do município (Estratégia Saúde da Família (ESF) e Unidade Básicas de Saúde (UBS)). Resultados: Houve predominância do sexo feminino, 56% declararam que continham ensino fundamental incompleto. A hipertensão arterial foi a comorbidade mais citada. Na avaliação da história clinica associada aos cuidados com os pés, 87% dos entrevistados, declararam que nunca tiveram nenhum tipo de ulceração nos pés. Na inspeção e avaliação dos pés dos entrevistados, constatou-se que 94% não tinham nenhum tipo de lesões nos pés. Conclusão: O estudo reforçou a importância da participação dos profissionais de saúde atuando na prevenção do pé diabético.(AU)

Objective: To evaluate the foot of individuals with Diabetes Melitus assisted in primary care in a city in the interior of São Paulo. Method: This is a quantitative study. One hundred feet of people with diabetes were examined, between the 1st and 31st of July, 2019, users of health services in the municipality (Family Health Strategy (ESF) and Basic Health Units (UBS). Results: There was a predominance of females, 56% declared that they had incomplete primary education. Hypertension was the most cited comorbidity. In the evaluation of the clinical history associated with foot care, 87% of the interviewees stated that they had never had any type of foot ulceration. Upon inspection and assessment of the respondents' feet, it was found that 94% did not have any type of foot injury. Conclusion: The study reinforced the importance of the participation of health professionals working in the prevention of diabetic foot.(AU)

Objetivo: Evaluar el pie de personas con Diabetes Melitus atendidas en atención primaria en una ciudad del interior de São Paulo. Método: Este es un estudio cuantitativo. Se examinaron cien pies de personas con diabetes, del 1 al 31 de julio de 2019, usuarios de los servicios de salud del municipio (Estrategia Salud de la Familia (ESF) y Unidades Básicas de Salud (UBS). Resultados: Predominó el sexo femenino, el 56% declaró tener educación primaria incompleta. La hipertensión fue la comorbilidad más citada. En la evaluación de la historia clínica asociada al cuidado de los pies, el 87% de los entrevistados afirmó no haber tenido nunca ningún tipo de ulceración del pie. Tras la inspección y evaluación de los pies de los encuestados, se encontró que el 94% no tenía ningún tipo de lesión en el pie. Conclusión: El estudio reforzó la importancia de la participación de los profesionales sanitarios que trabajan en la prevención del pie diabético.(AU)

Photoperiod and temperature as dominant environmental drivers triggering secondary growth resumption in Northern Hemisphere conifers.

Wood formation consumes around 15% of the anthropogenic CO2 emissions per year and plays a critical role in long-term sequestration of carbon on Earth. However, the exogenous factors driving wood formation onset and the underlying cellular mechanisms are still poorly understood and quantified, and this hampers an effective assessment of terrestrial forest productivity and carbon budget under global warming. Here, we used an extensive collection of unique datasets of weekly xylem tissue formation (wood formation) from 21 coniferous species across the Northern Hemisphere (latitudes 23 to 67°N) to present a quantitative demonstration that the onset of wood formation in Northern Hemisphere conifers is primarily driven by photoperiod and mean annual temperature (MAT), and only secondarily by spring forcing, winter chilling, and moisture availability. Photoperiod interacts with MAT and plays the dominant role in regulating the onset of secondary meristem growth, contrary to its as-yet-unquantified role in affecting the springtime phenology of primary meristems. The unique relationships between exogenous factors and wood formation could help to predict how forest ecosystems respond and adapt to climate warming and could provide a better understanding of the feedback occurring between vegetation and climate that is mediated by phenology. Our study quantifies the role of major environmental drivers for incorporation into state-of-the-art Earth system models (ESMs), thereby providing an improved assessment of long-term and high-resolution observations of biogeochemical cycles across terrestrial biomes.

Predicting care intensity in geriatric home care patients: a comparison of different measures.

BACKGROUND: Dependency in older ages is increasing. Many older persons receive care while living in the community. We aimed to identify the predictive value of four clinical measurements to predict home care intensity in older patients following discharge from hospital to home care over 90 days. METHODS: We included 425 inpatients from the "Frailty Department-Local Palliative Care Network" of the local social health authority (ASST) Lecco, Italy (mean age 75.4 years, SD 14.5; female 75.5%). Changes in Health, End-stage disease, and Signs and Symptoms, light version (CHESS-Lite), activities of daily living (ADL), frailty, and the Service Urgency Algorithm. Receiver operative curves were used to calculate the area under the curve (AUC) for predicting Home Care Intensity coefficient (ratio of the number of days when any home care was provided 90 days post-discharge). The interRAI Contact Assessment Instrument was used to calculate these measures. RESULTS: Analysis was stratified using six different home care intensity score cut-offs. CHESS-Lite had a higher AUC for predicting home care intensity at all cut-off levels but was best for predicting the highest level of home care intensity (≥ 0.8) where the AUC was 0.71 (0.64-0.79). The frailty index also had an acceptable AUC. ADL had the lowest AUC. CONCLUSIONS: Health instability measured with CHESS-Lite has a high predictive value for identifying home care intensity in geriatric patients after discharge from hospital to home, especially in persons with higher home care intensity scores. Geriatric patients with high health instability should be focused on at discharge to prioritize assessment and initiate timely services for home care support.

Early-Warning Signals of Individual Tree Mortality Based on Annual Radial Growth.

Tree mortality is a key driver of forest dynamics and its occurrence is projected to increase in the future due to climate change. Despite recent advances in our understanding of the physiological mechanisms leading to death, we still lack robust indicators of mortality risk that could be applied at the individual tree scale. Here, we build on a previous contribution exploring the differences in growth level between trees that died and survived a given mortality event to assess whether changes in temporal autocorrelation, variance, and synchrony in time-series of annual radial growth data can be used as early warning signals of mortality risk. Taking advantage of a unique global ring-width database of 3065 dead trees and 4389 living trees growing together at 198 sites (belonging to 36 gymnosperm and angiosperm species), we analyzed temporal changes in autocorrelation, variance, and synchrony before tree death (diachronic analysis), and also compared these metrics between trees that died and trees that survived a given mortality event (synchronic analysis). Changes in autocorrelation were a poor indicator of mortality risk. However, we found a gradual increase in inter-annual growth variability and a decrease in growth synchrony in the last ∼20 years before mortality of gymnosperms, irrespective of the cause of mortality. These changes could be associated with drought-induced alterations in carbon economy and allocation patterns. In angiosperms, we did not find any consistent changes in any metric. Such lack of any signal might be explained by the relatively high capacity of angiosperms to recover after a stress-induced growth decline. Our analysis provides a robust method for estimating early-warning signals of tree mortality based on annual growth data. In addition to the frequently reported decrease in growth rates, an increase in inter-annual growth variability and a decrease in growth synchrony may be powerful predictors of gymnosperm mortality risk, but not necessarily so for angiosperms.

Clinical Features of Kidney Transplant Recipients Admitted to the Intensive Care Unit.

INTRODUCTION: There is a paucity of data regarding the complications in kidney transplant patients who may require intensive care unit (ICU) management, despite being the most common solid organ transplant worldwide. OBJECTIVE: To identify the main reasons for ICU admission and to determine the factors associated with hospital mortality in kidney transplant recipients. DESIGN: This single-center retrospective cohort study was conducted between September 2013 and June 2014, including all consecutive kidney transplant patients requiring ICU admission. We collected data on patient demographics, transplant characteristics, clinical data, and prognostic scores. The independent determinants of hospital mortality were identified by multiple logistic regression analysis. We also assessed the performance of Simplified Acute Physiology Score 3 (SAPS 3) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores. RESULTS: We analyzed data from 413 patients, the majority of whom were admitted late after renal transplantation (1169 days; 63-3003 days). The main reason for admission was sepsis (33.2%), followed by cardiovascular disease (16%). Age (odds ratio [OR] 1.05, confidence interval [CI], 1.01-1.09), SAPS 3 score (OR 1.04, CI, 1.01-1.08), the need for mechanical ventilation (OR 26.47, CI, 10.30-68.08), and vasopressor use (OR 3.34, CI, 1.37-8.13) were independently associated with hospital mortality. The performance of SAPS 3 and APACHE II scores was poor in this population and overestimated the mortality rates. CONCLUSION: Sepsis was the main reason for ICU admission in kidney transplant recipients, followed by cardiovascular disease. Age and disease severity were associated with hospital mortality.

The influence of slope on Spartium junceum root system: morphological, anatomical and biomechanical adaptation.

Root systems have a pivotal role in plant anchorage and their mechanical interactions with the soil may contribute to soil reinforcement and stabilization of slide-prone slopes. In order to understand the responses of root system to mechanical stress induced by slope, samples of Spartium junceum L., growing in slope and in plane natural conditions, were compared in their morphology, biomechanical properties and anatomical features. Soils sampled in slope and plane revealed similar characteristics, with the exception of organic matter content and penetrometer resistance, both higher in slope. Slope significantly influenced root morphology and in particular the distribution of lateral roots along the soil depth. Indeed, first-order lateral roots of plants growing on slope condition showed an asymmetric distribution between up- and down-slope. Contrarily, this asymmetric distribution was not observed in plants growing in plane. The tensile strength was higher in lateral roots growing up-slope and in plane conditions than in those growing down-slope. Anatomical investigations revealed that, while roots grown up-slope had higher area covered by xylem fibers, the ratio of xylem and phloem fibers to root diameter did not differ among the three conditions, as also, no differences were found for xylem fiber cell wall thickness. Roots growing up-slope were the main contributors to anchorage properties, which included higher strength and higher number of fibers in the xylematic tissues. Results suggested that a combination of root-specific morphological, anatomical and biomechanical traits, determines anchorage functions in slope conditions.

A synthesis of radial growth patterns preceding tree mortality.

Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1-100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks.

Soil attributes and microclimate are important drivers of initial deadwood decay in sub-alpine Norway spruce forests.

Deadwood is known to significantly contribute to global terrestrial carbon stocks and carbon cycling, but its decay dynamics are still not thoroughly understood. Although the chemistry of deadwood has been studied as a function of decay stage in temperate to subalpine environments, it has generally not been related to time. We therefore studied the decay (mass of deadwood, cellulose and lignin) of equal-sized blocks of Picea abies wood in soil-mesocosms over two years in the Italian Alps. The 8 sites selected were along an altitudinal sequence, reflecting different climate zones. In addition, the effect of exposure (north- and south-facing slopes) was taken into account. The decay dynamics of the mass of deadwood, cellulose and lignin were related to soil parameters (pH, soil texture, moisture, temperature) and climatic data. The decay rate constants of Picea abies deadwood were low (on average between 0.039 and 0.040y(-1)) and of lignin close to zero (or not detectable), while cellulose reacted much faster with average decay rate constants between 0.110 and 0.117y(-1). Our field experiments showed that local scale factors, such as soil parameters and topographic properties, influenced the decay process: higher soil moisture and clay content along with a lower pH seemed to accelerate wood decay. Interestingly, air temperature negatively correlated with decay rates or positively with the amount of wood components on south-facing sites. It exerted its influence rather on moisture availability, i.e. the lower the temperature the higher the moisture availability. Topographic features were also relevant with generally slower decay processes on south-facing sites than on north-facing sites owing to the drier conditions, the higher pH and the lower weathering state of the soils (less clay minerals). This study highlights the importance of a multifactorial consideration of edaphic parameters to unravel the complex dynamics of initial wood decay.

Modeling the influence of alternative forest management scenarios on wood production and carbon storage: A case study in the Mediterranean region.

Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of forest ES represent future challenges. In this study, we developed a spatially explicit method based on a multi-scale approach (MiMoSe-Multiscale Mapping of ecoSystem services) to assess the current and future potential of a given forest area to provide ES. To do this we modified and improved the InVEST model in order to adapt input data and simulations to the context of Mediterranean forest ecosystems. Specifically, we integrated a GIS-based model, scenario model, and economic valuation to investigate two ES (wood production and carbon sequestration) and their trade-offs in a test area located in Molise region (Central Italy). Spatial information and trade-off analyses were used to assess the influence of alternative forest management scenarios on investigated services. Scenario A was designed to describe the current Business as Usual approach. Two alternative scenarios were designed to describe management approaches oriented towards nature protection (scenario B) or wood production (scenario C) and compared to scenario A. Management scenarios were simulated at the scale of forest management units over a 20-year time period. Our results show that forest management influenced ES provision and associated benefits at the regional scale. In the test area, the Total Ecosystem Services Value of the investigated ES increases 85% in scenario B and decreases 82% in scenario C, when compared to scenario A. Our study contributes to the ongoing debate about trade-offs and synergies between carbon sequestration and wood production benefits associated with socio-ecological systems. The MiMoSe approach can be replicated in other contexts with similar characteristics, thus providing a useful basis for the projection of benefits from forest ecosystems over the future.

Synchronisms and correlations of spring phenology between apical and lateral meristems in two boreal conifers.

Phenological synchronisms between apical and lateral meristems could clarify some aspects related to the physiological relationships among the different organs of trees. This study correlated the phenological phases of bud development and xylem differentiation during spring 2010-14 in balsam fir (Abies balsamea Mill.) and black spruce [(Picea mariana Mill. (BSP)] of the Monts-Valin National Park (Quebec, Canada) by testing the hypothesis that bud development occurs after the reactivation of xylem growth. From May to September, we conducted weekly monitoring of xylem differentiation using microcores and bud development with direct observations on terminal branches. Synchronism between the beginning of bud development and xylem differentiation was found in both species with significant correlations between the phases of bud and xylem phenology. Degree-day sum was more appropriate in assessing the date of bud growth resumption, while thermal thresholds were more suitable for cambium phenology. Our results provide new knowledge on the dynamics of spring phenology and novel information on the synchronisms between two meristems in coniferous trees. The study demonstrates the importance of precisely defining the phases of bud development in order to correctly analyse the relationships with xylem phenology.

Tree-ring stable isotopes reveal twentieth-century increases in water-use efficiency of Fagus sylvatica and Nothofagus spp. in Italian and Chilean mountains.

Changes in intrinsic water use efficiency (iWUE) were investigated in Fagus sylvatica and Nothofagus spp. over the last century. We combined dendrochronological methods with dual-isotope analysis to investigate whether atmospheric changes enhanced iWUE of Fagus and Nothofagus and tree growth (basal area increment, BAI) along latitudinal gradients in Italy and Chile. Post-maturation phases of the trees presented different patterns in δ13C, Δ13C, δ18O, Ci (internal CO2 concentration), iWUE, and BAI. A continuous enhancement in isotope-derived iWUE was observed throughout the twentieth century, which was common to all sites and related to changes in Ca (ambient CO2 concentration) and secondarily to increases in temperature. In contrast to other studies, we observed a general increasing trend of BAI, with the exception of F. sylvatica in Aspromonte. Both iWUE and BAI were uncoupled with the estimated drought index, which is in agreement with the absence of enduring decline in tree growth. In general, δ13C and δ18O showed a weak relationship, suggesting the major influence of photosynthetic rate on Ci and δ13C, and the minor contribution of the regulation of stomatal conductance to iWUE. The substantial warming observed during the twentieth century did not result in a clear pattern of increased drought stress along these latitudinal transects, because of the variability in temporal trends of precipitation and in specific responses of populations.

Rattlesnake hemoglobins: Functional properties and tetrameric stability.

The present work analyzed the tetrameric stability of the hemoglobins from the rattlesnake C. durissus terrificus using analytical gel filtration chromatography, SAXS and osmotic stress. We show that the dissociation mechanism proposed for L. miliaris hemoglobin does not apply for these hemoglobins, which constitute stable tetramers even at low concentrations.