Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests.

Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, [Formula: see text]50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters [Formula: see text]50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both [Formula: see text]50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.

Genetic Ancestry, Race, and Severity of Acutely Decompensated Cirrhosis in Latin America.

BACKGROUND & AIMS: Genetic ancestry or racial differences in health outcomes exist in diseases associated with systemic inflammation (eg, COVID-19). This study aimed to investigate the association of genetic ancestry and race with acute-on-chronic liver failure (ACLF), which is characterized by acute systemic inflammation, multi-organ failure, and high risk of short-term death. METHODS: This prospective cohort study analyzed a comprehensive set of data, including genetic ancestry and race among several others, in 1274 patients with acutely decompensated cirrhosis who were nonelectively admitted to 44 hospitals from 7 Latin American countries. RESULTS: Three hundred ninety-five patients (31.0%) had ACLF of any grade at enrollment. Patients with ACLF had a higher median percentage of Native American genetic ancestry and lower median percentage of European ancestry than patients without ACLF (22.6% vs 12.9% and 53.4% vs 59.6%, respectively). The median percentage of African genetic ancestry was low among patients with ACLF and among those without ACLF. In terms of race, a higher percentage of patients with ACLF than patients without ACLF were Native American and a lower percentage of patients with ACLF than patients without ACLF were European American or African American. In multivariable analyses that adjusted for differences in sociodemographic and clinical characteristics, the odds ratio for ACLF at enrollment was 1.08 (95% CI, 1.03-1.13) with Native American genetic ancestry and 2.57 (95% CI, 1.84-3.58) for Native American race vs European American race CONCLUSIONS: In a large cohort of Latin American patients with acutely decompensated cirrhosis, increasing percentages of Native American ancestry and Native American race were factors independently associated with ACLF at enrollment.

Bornean tropical forests recovering from logging at risk of regeneration failure.

Active restoration through silvicultural treatments (enrichment planting, cutting climbers and liberation thinning) is considered an important intervention in logged forests. However, its ability to enhance regeneration is key for long-term recovery of logged forests, which remains poorly understood, particularly for the production and survival of seedlings in subsequent generations. To understand the long-term impacts of logging and restoration we tracked the diversity, survival and traits of seedlings that germinated immediately after a mast fruiting in North Borneo in unlogged and logged forests 30-35 years after logging. We monitored 5119 seedlings from germination for ~1.5 years across a mixed landscape of unlogged forests (ULs), naturally regenerating logged forests (NR) and actively restored logged forests via rehabilitative silvicultural treatments (AR), 15-27 years after restoration. We measured 14 leaf, root and biomass allocation traits on 399 seedlings from 15 species. Soon after fruiting, UL and AR forests had higher seedling densities than NR forest, but survival was the lowest in AR forests in the first 6 months. Community composition differed among forest types; AR and NR forests had lower species richness and lower evenness than UL forests by 5-6 months post-mast but did not differ between them. Differences in community composition altered community-weighted mean trait values across forest types, with higher root biomass allocation in NR relative to UL forest. Traits influenced mortality ~3 months post-mast, with more acquisitive traits and relative aboveground investment favoured in AR forests relative to UL forests. Our findings of reduced seedling survival and diversity suggest long time lags in post-logging recruitment, particularly for some taxa. Active restoration of logged forests recovers initial seedling production, but elevated mortality in AR forests lowers the efficacy of active restoration to enhance recruitment or diversity of seedling communities. This suggests current active restoration practices may fail to overcome barriers to regeneration in logged forests, which may drive long-term changes in future forest plant communities.

A restauração ativa por meio de tratamentos silviculturais (plantio de enriquecimento, corte de trepadeiras e desbaste) é considerada uma intervenção importante em florestas com exploração de madeira. No entanto, sua capacidade de melhorar a regeneração, essencial para a recuperação de longo prazo das florestas exploradas, permanece pouco compreendida, especialmente no que diz respeito à produção e sobrevivência de mudas em gerações subsequentes. Para compreender os impactos de longo prazo da exploração madeireira e da restauração, acompanhamos a diversidade, sobrevivência e características de plântulas que germinaram imediatamente após uma frutificação em massa no norte de Bornéu, em florestas com e sem exploração de madeira, 30-35 anos após o fim da extração. Monitoramos 5119 mudas desde a germinação por aproximadamente 1,5 anos em uma paisagem mista de florestas não exploradas (UL), florestas exploradas em regeneração natural (NR) e florestas exploradas restauradas ativamente por meio de tratamentos silviculturais de reabilitação (AR), 15-27 anos após a restauração. Medimos 14 traços funcionais de folhas, raízes e alocação de biomassa em 399 mudas de 15 espécies. Logo após a frutificação, as florestas UL e AR apresentaram densidades de mudas mais altas do que as florestas NR, mas a sobrevivência foi mais baixa nas florestas AR nos primeiros seis meses. A composição da comunidade diferiu entre os tipos de floresta; as florestas AR e NR teviram menor riqueza de espécies e menor equidade do que as florestas UL 5-6 meses após a frutificação, mas não diferiram entre si. As diferenças na composição da comunidade alteraram os valores de média ponderada pela comunidade das características entre os tipos de floresta com maior alocação de biomassa radicular nas florestas NR em relação às florestas UL. As características influenciaram a mortalidade aproximadamente 3 meses após a frutificação, com traços mais aquisitivos maior investimento em biomassa relativa acima do solo nas florestas AR em relação às florestas UL. Nossas descobertas de redução na sobrevivência e diversidade de plântulas sugerem que há longos retardos no recrutamento após o fim da exploração de madeira, particularmente para alguns táxons. A restauração ativa de florestas exploradas recupera a produção inicial de plântulas, mas a mortalidade elevada nas florestas AR diminui a eficácia da restauração ativa no melhorio do recrutamento e da diversidade das comunidades de mudas. Isso sugere que as práticas atuais de restauração ativa podem não superar as barreiras à regeneração em florestas exploradas, o que pode levar a mudanças de longo prazo nas comunidades florestais no futuro.

Influence of Tacrolimus Intrapatient Variability on Allograft Rejection Frequency and Survival Following Liver Transplantation.

BACKGROUND: Tacrolimus is the primary calcineurin inhibitor used in immunosuppressive regimens to prevent allograft rejection (AR) after organ transplantation. Recent studies have linked intrapatient variability (IPV) of tacrolimus with AR occurrence and reduced survival, especially in kidney transplant recipients. However, limited data are available on the impact of tacrolimus IPV on adverse outcomes after liver transplantation (LT). AIMS: The aim of this study was to assess the association between tacrolimus IPV using various methodologies with acute AR and long-term patient survival after LT. METHODS: All patients who underwent LT from January 2010 to July 2021 were retrospectively evaluated. Tacrolimus IPV was calculated for each patient using the mean and SD, mean absolute deviation (MAD), coefficient of variation (CV), and time in therapeutic range (TTR). These measures were then compared with AR within the first 24 months after LT and to long-term survival. RESULTS: Out of 234 patients, 32 (13.7%) developed AR and 183 (78.2%) survived, with a mean follow-up of 101 ± 43 months. Tacrolimus IPV, assessed by mean, SD, MAD, and CV, was 8.3 ± 2.1, 2.7 ± 1.3, 32.0% ± 11.7%, and 39.4% ± 15.4%, respectively. There was no statistically significant correlation between Tacrolimus IPV and AR or survival post-LT. CONCLUSIONS: In a large cohort of patients from diverse racial backgrounds, tacrolimus IPV was not associated with clinically relevant outcomes such as AR and survival after LT.

Retrieval of HCV patients lost to follow-up as a strategy for Hepatitis C Microelimination: results of a Brazilian multicentre study.

BACKGROUND: Several HCV patients in Brazil were lost to follow-up (LTFU) in the last two decades before achievement of sustained virological response (SVR). Strategies to recall those diagnosed but untreated patients have been used elsewhere with different success rates. AIM: To identify and retrieve LTFU patients in order to offer them the treatment with the current highly effective direct acting antiviral agents (DAAs). METHODS: Registries ofall HCV patients from three large reference centers in Brazil were retrospectively reviewed to identify those with no registry of SVR. Reasons for non-achievement of SVR were elicited in HCV-RNA + patients. All patients who were not treated or cured were contacted to offer the therapy with DAAs. RESULTS: 10,289 HCV patients (50% males, mean age 52 ± 11 years) were identified. Only 4,293 (41.7%) had been successfully treated previously. From the remaining 5,996 most were LTFU (59%), were not treated for other reasons (14.7%) or were non-responders (26.3%). After revision of the charts 3,559 were considered eligible to be retrieved. The callback success of phone calls was 18%, 13% to cellphone messages (SMS or WhatsApp) and 7% to regular mail. Five-hundred sixty patients had been already treatedor were on treatment and 234 were reported to be dead or transplanted. Finally, 201 had made an appointment and initiated antiviral treatment. CONCLUSION: Even considering the low callback rate, retrieval of LTFU patients was shown to be an important strategy forhepatitis C micro-elimination in Brazil.

Response to Ursodeoxycholic Acid May Be Assessed Earlier to Allow Second-Line Therapy in Patients with Unresponsive Primary Biliary Cholangitis.

BACKGROUND: Response to ursodeoxycholic acid (UDCA) in primary biliary cholangitis (PBC) has been traditionally assessed 1 to 2 years after treatment initiation. With the development of new drugs, some patients may benefit from an earlier introduction of second-line therapies. AIMS: This study aims to identify whether well-validated response criteria could correctly identify individuals likely to benefit from add-on second-line therapy at 6 months. METHODS: Analysis of a multicenter retrospective cohort which included only patients with clear-cut PBC. RESULTS: 206 patients with PBC (96.6% women; mean age 54 ± 12 years) were included. Kappa concordance was substantial for Toronto (0.67), Rotterdam (0.65), Paris 1 (0.63) and 2 (0.63) criteria at 6 and 12 months, whereas Barcelona (0.47) and POISE trial (0.59) criteria exhibited moderate agreement. Non-response rates to UDCA was not statistically different when assessed either at 6 or 12 months using Toronto, Rotterdam or Paris 2 criteria. Those differences were even smaller or absent in those subjects with advanced PBC. Mean baseline alkaline phosphatase was 2.73 ± 1.95 times the upper limit of normal (× ULN) among responders versus 5.05 ± 3.08 × ULN in non-responders (p < 0.001). CONCLUSIONS: After 6 months of treatment with UDCA, the absence of response by different criteria could properly identify patients who could benefit from early addition of second-line therapies, especially in patients with advanced disease or high baseline liver enzymes levels.

Choosing wisely recommendations regarding the top five list of procedures to avoid in the treatment of viral hepatitis: A position statement from the Brazilian Society of Hepatology endorsed by the Latin American Association for the Study of the liver.

INTRODUCTION AND OBJECTIVES: The Choosing Wisely (CW) initiative aims to improve daily practice supported by evidence concerning unnecessary medical tests, procedures, and treatments. This philosophy is essential in managing viral hepatitis (VH), which primary care physicians increasingly carry out. It is also essential to achieving disease elimination. Thus, the aim of our study was to propose evidence-based CW recommendations in VH. MATERIALS AND METHODS: The Brazilian Society of Hepatology (SBH) formed a panel of experts in VH who selected evidence-based CW recommendations, which were subsequently scrutinized and ranked by all members of SBH using a web-based approach. RESULTS: Five recommendations were chosen in order of importance: 1) do not order anti-HCV testing after achieving sustained virological response; 2) do not request serial HCV viral load to evaluate HCV progression, 3) do not add ribavirin to direct-acting antivirals in non-cirrhotic, naïve HCV patients; 4) do not screen for hepatocellular carcinoma in HCV patients with none to moderate fibrosis (≤ F2); 5) do not request anti-HBs after HBV vaccination, except for children born to HBV-infected mothers, hemodialysis patients, healthcare professionals, people who have had sexual contact with chronic HBV carriers, HIV-positive persons and immunocompromised individuals (hematopoietic stem-cell transplant recipients or persons receiving chemotherapy). CONCLUSIONS: CW recommendations may help general practitioners adopt a more rational and cost-effective approach in managing patients with VH in Brazil and Latin America, leading to lesser waste or harm to patients.

Risk factors for cancer in patients with primary biliary cholangitis and autoimmune hepatitis and primary biliary cholangitis overlap syndrome.

INTRODUCTION AND OBJECTIVES: Primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) and PBC overlap syndrome (AIH/PBC) have been associated with a higher risk of hepatocellular carcinoma (HCC) and extra-hepatic malignancy (EHM). This study aims to assess potential risk factors associated with cancer development in PBC and AIH/PBC. MATERIALS AND METHODS: The Brazilian Cholestasis Study Group database was reviewed to compare clinical and laboratory features of PBC patients with HCC and EHM with those without cancer. RESULTS: Among the 752 PBC patients enrolled, 64 of them with AIH/PBC, 87 cancers were identified in 72 patients, including 20 cases of HCC and 67 of EHM. Patients with HCC had a higher prevalence of cirrhosis (95% vs. 32.5% of those subjects without cancer, p≤0.001), smoking (55% vs. 12.3%, p≤0.001), CREST syndrome (30% vs 7.6%, p=0.003) and prior azathioprine (30% vs 8%, p= 0.005) and prednisone (35% vs 14%, p= 0.018) use, whereas patients with EHM had a higher prevalence of smoking (42.3% vs 12.4% of those subjects without cancer, p= <0.001), AMA positivity (96.6% vs 80.1%, p≤0.001), azathioprine therapy (21% vs 7.9%, p= 0.01) and concurrent other autoimmune diseases. In multivariate analysis, cirrhosis, obesity and prior azathioprine therapy were independent risk factors for HCC, while Sjogren syndrome and psoriasis were associated with EHM. Fibrates reduced EHM risk. CONCLUSIONS: The prevalence of EHM is higher when compared to HCC in PBC patients. Cirrhosis, obesity, prior azathioprine use, and concurrent autoimmune diseases were significantly associated with cancer in PBC.

Telemonitoring of the Continuum of Care of Hepatitis C During the COVID-19 Pandemic in Brazil.

Introduction: To accomplish elimination of hepatitis C virus (HCV) by 2030, as proposed by the World Health Organization, the Brazilian Ministry of Health outlined the Hepatitis C Elimination Plan, which provides coverage of all critical steps in the continuum of care (CoC) of hepatitis C. As expected, the advent of COVID-19 pandemic has disrupted the CoC of hepatitis C worldwide. The Brazilian Liver Institute launched a remote patient monitoring (RPM) program to assist the general population at risk in HCV testing and to provide linkage and retention to care for HCV-positive subjects. The RPM program was also designed to relink HCV-positive patients lost to follow-up during the COVID-19 pandemic due to their limited access to the health care system. Methods: The HCV telemonitoring number was highly advertised in Brazilian media. The RPM program was conducted by dedicated health care personnel trained to follow a predefined script designed to provide awareness, ensure consistent information for educational purposes, and recruit eligible participants to be tested for HCV. Results: From August 2020 to December 2021, 3,738 subjects entered in contact with RPM. There were 26,884 interactions (mean 7.2 interactions per participant), mostly by WhatsApp (78%). Twenty out of those 221 subjects (9%) who tested were HCV positive. Those subjects altogether with 128 other patients with HCV, tested elsewhere, were followed in the HCV CoC. Up to now, 94% of them were linked to care, 24% are undergoing treatment and 8% achieved sustained virological response (SVR). Conclusions: Our preliminary results showed that HCV CoC telemonitoring was a feasible and useful strategy to follow HCV at-risk subjects through all cascade of care until SVR during the COVID-19 health care disruption. It could be used beyond the defervescence of SARS-CoV-2 pandemic to ensure linkage to care of those HCV-positive patients.

Divergence of hydraulic traits among tropical forest trees across topographic and vertical environment gradients in Borneo.

Fine-scale topographic-edaphic gradients are common in tropical forests and drive species spatial turnover and marked changes in forest structure and function. We evaluate how hydraulic traits of tropical tree species relate to vertical and horizontal spatial niche specialization along such a gradient. Along a topographic-edaphic gradient with uniform climate in Borneo, we measured six key hydraulic traits in 156 individuals of differing heights in 13 species of Dipterocarpaceae. We investigated how hydraulic traits relate to habitat, tree height and their interaction on this gradient. Embolism resistance increased in trees on sandy soils but did not vary with tree height. By contrast, water transport capacity increased on sandier soils and with increasing tree height. Habitat and height only interact for hydraulic efficiency, with slope for height changing from positive to negative from the clay-rich to the sandier soil. Habitat type influenced trait-trait relationships for all traits except wood density. Our data reveal that variation in the hydraulic traits of dipterocarps is driven by a combination of topographic-edaphic conditions, tree height and taxonomic identity. Our work indicates that hydraulic traits play a significant role in shaping forest structure across topographic-edaphic and vertical gradients and may contribute to niche specialization among dipterocarp species.

Small and slow is safe: On the drought tolerance of tropical tree species.

Understanding how evolutionary history and the coordination between trait trade-off axes shape the drought tolerance of trees is crucial to predict forest dynamics under climate change. Here, we compiled traits related to drought tolerance and the fast-slow and stature-recruitment trade-off axes in 601 tropical woody species to explore their covariations and phylogenetic signals. We found that xylem resistance to embolism (P50) determines the risk of hydraulic failure, while the functional significance of leaf turgor loss point (TLP) relies on its coordination with water use strategies. P50 and TLP exhibit weak phylogenetic signals and substantial variation within genera. TLP is closely associated with the fast-slow trait axis: slow species maintain leaf functioning under higher water stress. P50 is associated with both the fast-slow and stature-recruitment trait axes: slow and small species exhibit more resistant xylem. Lower leaf phosphorus concentration is associated with more resistant xylem, which suggests a (nutrient and drought) stress-tolerance syndrome in the tropics. Overall, our results imply that (1) drought tolerance is under strong selective pressure in tropical forests, and TLP and P50 result from the repeated evolutionary adaptation of closely related taxa, and (2) drought tolerance is coordinated with the ecological strategies governing tropical forest demography. These findings provide a physiological basis to interpret the drought-induced shift toward slow-growing, smaller, denser-wooded trees observed in the tropics, with implications for forest restoration programmes.

Anti-mitochondrial Antibody-Negative Primary Biliary Cholangitis Is Part of the Same Spectrum of Classical Primary Biliary Cholangitis.

BACKGROUND: Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease in which anti-mitochondrial antibodies (AMA) are the diagnostic hallmark. Whether AMA-negative PBC patients represent a different phenotype of disease is highly debated. AIMS: The purpose of our study was to compare AMA-positive and AMA-negative PBC patients in a large non-white admixed Brazilian cohort. METHODS: The Brazilian Cholestasis Study Group multicentre database was reviewed to assess demographics, clinical features and treatment outcomes of Brazilian PBC patients, stratifying data according to AMA status. RESULTS: A total of 464 subjects (95.4% females, mean age 56 ± 5 years) with PBC were included. Three hundred and eighty-four (83%) subjects were AMA-positive, whereas 80 (17%) had AMA-negative PBC. Subjects with AMA-negative PBC were significantly younger (52.2 ± 14 vs. 59.6 ± 11 years, p = 0.001) and had their first symptom at an earlier age (43.2 ± 13 vs. 49.5 ± 12 years, p = 0.005). Frequency of type 2 diabetes was significantly increased in subjects with AMA-negative PBC (22.5% vs. 12.2%, p = 0.03). Lower IgM (272.2 ± 183 vs. 383.2 ± 378 mg/dL, p = 0.01) and triglycerides (107.6 ± 59.8 vs.129.3 ± 75.7 mg/dL, p = 0.025) and higher bilirubin (3.8 ± 13.5 vs. 1.8 ± 3.4 mg/dL, p = 0.02) levels were also observed in this subgroup. Response to ursodeoxycholic acid varied from 40.5 to 63.3% in AMA-positive and 34 to 62.3% in AMA-negative individuals, according to different response criteria. Outcomes such as development of liver-related complications, death and requirement for liver transplantation were similar in both groups. CONCLUSIONS: AMA-negative PBC patients are similar to their AMA-positive counterparts with subtle differences observed in clinical and laboratory features.

Clinical features and treatment outcomes of primary biliary cholangitis in a highly admixed population.

INTRODUCTION AND OBJECTIVES: Little is known about primary biliary cholangitis (PBC) in non-whites. The purpose of this study was to evaluate clinical features and outcomes of PBC in a highly admixed population. MATERIAL AND METHODS: The Brazilian Cholestasis Study Group multicentre database was reviewed to assess demographics, clinical features and treatment outcomes of Brazilian patients with PBC. RESULTS: 562 patients (95% females, mean age 51 ± 11 years) with PBC were included. Concurrent autoimmune diseases and overlap with autoimmune hepatitis (AIH) occurred, respectively, in 18.9% and 14%. After a mean follow-up was 6.2 ± 5.3 years, 32% had cirrhosis, 7% underwent liver transplantation and 3% died of liver-related causes. 96% were treated with ursodeoxycholic acid (UDCA) and 12% required add-on therapy with fibrates, either bezafibrate, fenofibrate or ciprofibrate. Response to UDCA and to UDCA/fibrates therapy varied from 39%-67% and 42-61%, respectively, according to different validated criteria. Advanced histological stages and non-adherence to treatment were associated with primary non-response to UDCA, while lower baseline alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels correlated with better responses to both UDCA and UDCA/fibrates. CONCLUSIONS: Clinical features of PBC in highly admixed Brazilians were similar to those reported in Caucasians and Asians, but with inferior rates of overlap syndrome with AIH. Response to UDCA was lower than expected and inversely associated with histological stage and baseline AST and ALP levels. Most of patients benefited from add-on fibrates, including ciprofibrate. A huge heterogeneity in response to UDCA therapy according to available international criteria was observed and reinforces the need of global standardization.

Linking plant hydraulics and the fast-slow continuum to understand resilience to drought in tropical ecosystems.

Tropical ecosystems have the highest levels of biodiversity, cycle more water and absorb more carbon than any other terrestrial ecosystem on Earth. Consequently, these ecosystems are extremely important components of Earth's climatic system and biogeochemical cycles. Plant hydraulics is an essential discipline to understand and predict the dynamics of tropical vegetation in scenarios of changing water availability. Using published plant hydraulic data we show that the trade-off between drought avoidance (expressed as deep-rooting, deciduousness and capacitance) and hydraulic safety (P50 - the water potential when plants lose 50% of their maximum hydraulic conductivity) is a major axis of physiological variation across tropical ecosystems. We also propose a novel and independent axis of hydraulic trait variation linking vulnerability to hydraulic failure (expressed as the hydraulic safety margin (HSM)) and growth, where inherent fast-growing plants have lower HSM compared to slow-growing plants. We surmise that soil nutrients are fundamental drivers of tropical community assembly determining the distribution and abundance of the slow-safe/fast-risky strategies. We conclude showing that including either the growth-HSM or the resistance-avoidance trade-off in models can make simulated tropical rainforest communities substantially more vulnerable to drought than similar communities without the trade-off. These results suggest that vegetation models need to represent hydraulic trade-off axes to accurately project the functioning and distribution of tropical ecosystems.

Plant traits controlling growth change in response to a drier climate.

Plant traits are increasingly being used to improve prediction of plant function, including plant demography. However, the capability of plant traits to predict demographic rates remains uncertain, particularly in the context of trees experiencing a changing climate. Here we present data combining 17 plant traits associated with plant structure, metabolism and hydraulic status, with measurements of long-term mean, maximum and relative growth rates for 176 trees from the world's longest running tropical forest drought experiment. We demonstrate that plant traits can predict mean annual tree growth rates with moderate explanatory power. However, only combinations of traits associated more directly with plant functional processes, rather than more commonly employed traits like wood density or leaf mass per area, yield the power to predict growth. Critically, we observe a shift from growth being controlled by traits related to carbon cycling (assimilation and respiration) in well-watered trees, to traits relating to plant hydraulic stress in drought-stressed trees. We also demonstrate that even with a very comprehensive set of plant traits and growth data on large numbers of tropical trees, considerable uncertainty remains in directly interpreting the mechanisms through which traits influence performance in tropical forests.

Brazilian Society of Hepatology and Brazilian College of Radiology practice guidance for the use of elastography in liver diseases.

In 2015 the European Association for the Study of Liver Diseases (EASL) and the Asociación Latinoamericana para el Estudio del Hígado (ALEH) published a guideline for the use of non-invasive markers of liver disease. At that time, this guideline focused on the available data regarding ultrasonic-related elastography methods. Since then, much has been published, including new data about XL probe use in transient elastography, magnetic resonance elastography, and non-invasive liver steatosis evaluation. In order to draw evidence-based guidance concerning the use of elastography for non-invasive assessment of fibrosis and steatosis in different chronic liver diseases, the Brazilian Society of Hepatology (SBH) and the Brazilian College of Radiology (CBR) sponsored a single-topic meeting on October 4th, 2019, at São Paulo, Brazil. The aim was to establish specific recommendations regarding the use of imaging-related non-invasive technology to diagnose liver fibrosis and steatosis based on the discussion of evidence-based topics by an organizing committee of experts. It was submitted online to all SBH and CBR members. The present document is the final version of the manuscript that supports the use of this new technology as an alternative to liver biopsy.

Impact of Brazilian expanded criteria for liver transplantation in patients with hepatocellular carcinoma: a multicenter study.

INTRODUCTION AND OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the main indications for orthotopic liver transplantation (OLT). In Brazil, selection criteria for HCC is an expanded version of the Milan Criteria (MC), the so-called "Brazilian Milan Criteria" (BMC). Our aims were to evaluate post-OLT outcomes in patients with HCC and analyze the BMC performance. MATERIALS AND METHODS: We conducted a multicenter, retrospective cohort study, analyzing medical records of 1,059 liver transplant recipients with HCC. Tumor was staged according to MC and BMC and correlated with overall survival (OS) and disease-free survival (DFS). We compared the ability of MC and BMC to predict OS and DFS using Delta C-statistic. RESULTS: Post-OLT OS were 63% in five years and HCC recurrence was observed in 8% of patients. At diagnosis, 85% of patients were within MC. Patients within MC at diagnosis and in the explant showed a higher OS and DFS than patients outside MC and within BMC and patients outside both criteria (p < 0.001). Patients outside MC in the explant had an increased risk of tumor recurrence (HR: 3.78; p < 0.001) and poor survival (HR:1.77; p = 0.003). The BMC presented a lower performance than MC in properly classifying patients regarding recurrence risk. CONCLUSIONS: In a large Brazilian cohort of HCC patients submitted to liver transplantation, we observed satisfactory overall survival and recurrence rates. However, patients transplanted within the Brazilian expanded criteria had lower OS and DFS when compared to patients within MC, which may generate future discussions regarding the criteria currently used.

Ultrasound: a suitable technology to improve the extraction and techno-functional properties of vegetable food proteins.

Vegetable-based proteins may be extracted from different sources using different extraction methods, among them, ultrasound-assisted extraction stands out. This review presents the current knowledge on ultrasound-assisted extraction (UAE) and the functional properties of extracted vegetable proteins. Ultrasound generates cavitation in a liquid medium, defined as gas and vapor microbubbles collapse under pressure changes large enough to separate them in the medium. Cavitation facilitates the solvent and solid interaction, increasing yield and reducing extraction periods and temperature used. Moreover, ultrasound treatment changed extracted protein properties such as solubility, hydrophobicity, emulsifying and foam, water and oil absorption capacity, viscosity, and gelatinization. Ultrasound-assisted extraction is a promising technique for the food technology sector, presenting low environmental impact, lower energy and solvent consumption, and it is in accordance with green chemistry technology and sustainable concepts.

Convergent evolution of tree hydraulic traits in Amazonian habitats: implications for community assemblage and vulnerability to drought.

Amazonian droughts are increasing in frequency and severity. However, little is known about how this may influence species-specific vulnerability to drought across different ecosystem types. We measured 16 functional traits for 16 congeneric species from six families and eight genera restricted to floodplain, swamp, white-sand or plateau forests of Central Amazonia. We investigated whether habitat distributions can be explained by species hydraulic strategies, and if habitat specialists differ in their vulnerability to embolism that would make water transport difficult during drought periods. We found strong functional differences among species. Nonflooded species had higher wood specific gravity and lower stomatal density, whereas flooded species had wider vessels, and higher leaf and xylem hydraulic conductivity. The P50 values (water potential at 50% loss of hydraulic conductivity) of nonflooded species were significantly more negative than flooded species. However, we found no differences in hydraulic safety margin among species, suggesting that all trees may be equally likely to experience hydraulic failure during severe droughts. Water availability imposes a strong selection leading to differentiation of plant hydraulic strategies among species and may underlie patterns of adaptive radiation in many tropical tree genera. Our results have important implications for modeling species distribution and resilience under future climate scenarios.

Small tropical forest trees have a greater capacity to adjust carbon metabolism to long-term drought than large canopy trees.

The response of small understory trees to long-term drought is vital in determining the future composition, carbon stocks and dynamics of tropical forests. Long-term drought is, however, also likely to expose understory trees to increased light availability driven by drought-induced mortality. Relatively little is known about the potential for understory trees to adjust their physiology to both decreasing water and increasing light availability. We analysed data on maximum photosynthetic capacity (Jmax , Vcmax ), leaf respiration (Rleaf ), leaf mass per area (LMA), leaf thickness and leaf nitrogen and phosphorus concentrations from 66 small trees across 12 common genera at the world's longest running tropical rainfall exclusion experiment and compared responses to those from 61 surviving canopy trees. Small trees increased Jmax , Vcmax , Rleaf and LMA (71, 29, 32, 15% respectively) in response to the drought treatment, but leaf thickness and leaf nutrient concentrations did not change. Small trees were significantly more responsive than large canopy trees to the drought treatment, suggesting greater phenotypic plasticity and resilience to prolonged drought, although differences among taxa were observed. Our results highlight that small tropical trees have greater capacity to respond to ecosystem level changes and have the potential to regenerate resilient forests following future droughts.