Lianas in tropical dry seasonal forests have a high hydraulic efficiency but not always a higher embolism resistance than lianas in rainforests.

BACKGROUND AND AIMS: Lianas have higher relative abundance and biomass in drier seasonal forests than rainforests, but whether this difference is associated with their hydraulic strategies is unclear. Here, we investigate whether lianas of seasonally dry forests are safer and more efficient in water transport than rainforest ones, explaining liana abundance patterns. METHODS: We measured hydraulic traits on five pairs of congeneric lianas of the tribe Bignonieae in two contrasting forest sites: the wet 'Dense Ombrophilous Forest' in the Central Amazonia (~ 2 dry months) and the drier 'Semideciduous Seasonal Forest' in the inland Atlantic Forest (~6 dry months). We also gathered a broader database, including 197 trees and 58 liana species from different tropical forests, to compare hydraulic safety between habits and forest types. KEY RESULTS: Bignonieae lianas from both forests had high and similar hydraulic efficiency and exhibited variability in resistance to embolism across forest types when phylogenetic relationships are taken into account. Three genera had higher hydraulic safety in the seasonal forest than in the rainforest, but species across both forests had similar positive hydraulic safety margin despite lower predawn water potential values of seasonal forest' lianas. We did not find the safety-efficiency trade-off. Merging our results with previously published data evidenced a high variability of resistance to embolism in both trees and lianas, independent of forest types. CONCLUSIONS: The high hydraulic efficiency of lianas detected here probably favors their rapid growth across tropical forests, but differences in hydraulic safety highlight that some species are highly vulnerable and may rely on other mechanisms to cope with drought. Future research on the lethal dehydration threshold and the connection between hydraulic resistance strategies and liana abundance could offer further insights into tropical forest dynamics under climatic threats.

Role of fiberoptic endoscopic evaluation of swallowing (FEES) in children with suspected dysphagia.

OBJECTIVE: To assess FEES findings in defining oral feeding safety in children with suspected dysphagia, comparing them with clinical feeding evaluation results. METHODS: This study comprised a case series involving children with suspected dysphagia, referred for evaluation by otolaryngologists and speech-language pathologists (SLPs) at a Brazilian quaternary public university hospital. These children underwent both clinical evaluations and fiberoptic endoscopic evaluation of swallowing (FEES), with a comprehensive collection of demographic and clinical data. Subsequently, the authors performed a comparative analysis of findings from both assessments. RESULTS: Most patients successfully completed the FEES procedure (93.7%), resulting in a final number of 60 cases included in the study. The prevalence of dysphagia was confirmed in a significant 88% of these cases. Suspected aspiration on clinical SLP evaluation was present in 34 patients. Of these, FEES confirmed aspiration or penetration in 28 patients. Among the 35 patients with aspiration or penetration on FEES, 7 (20%) had no suspicion on SLP clinical assessment. All seven patients in whom clinical SLP evaluation failed to predict penetration/aspiration had neurological disorders. The median age of the children was 2.8 years, and 49 (81.6%) had neurological disorders, while 35 (58.3%) had chronic pulmonary disease. The most prevalent complaints were choking (41.6%) and sialorrhea (23.3%). CONCLUSION: FEES can diagnose structural anomalies of the upper aerodigestive tract and significantly contribute to the detection of aspiration and penetration in this group of patients with suspected dysphagia, identifying moderate and severe dysphagia even in cases where clinical assessment had no suspicion.

Bilateral acute depigmentation of the iris (BADI) and bilateral acute iris transillumination (BAIT): A case series from a center in Brazil.

Bilateral acute depigmentation of the iris and bilateral acute iris transillumination (BAIT) are similar clinical entities. The former causes acute-onset depigmentation of the iris stroma without transillumination, whereas the latter causes depigmentation of the iris pigment epithelium with transillumination. The etiopathogenesis of these conditions is not yet fully understood, but the proposed causes include the use of systemic antibiotics (especially moxifloxacin) and viral triggers. We present a case series of five female patients with a mean age of 41 (32-45) years, all of whom suffered acute onset of bilateral pain and redness of the eyes after moxifloxacin use (oral or topical). It is important for ophthalmologists to be aware of the two forms of iris depigmentation since this case series suggests that SARS-CoV-2 or its empirical treatment with moxifloxacin may trigger iris depigmentation. If this is the case, clinicians will likely see increased incidences of bilateral acute depigmentation of the iris and bilateral acute iris transillumination during and after the COVID-19 pandemic.

Association of the IFNG +874T/A Polymorphism with Symptomatic COVID-19 Susceptibility.

Tumor necrosis factor (TNF) and interferon-gamma (IFNγ) are important inflammatory mediators in the development of cytokine storm syndrome (CSS). Single nucleotide polymorphisms (SNPs) regulate the expression of these cytokines, making host genetics a key factor in the prognosis of COVID-19. In this study, we investigated the associations of the TNF -308G/A and IFNG +874T/A polymorphisms with COVID-19. We analyzed the frequencies of the two polymorphisms in the control groups (CG: TNF -308G/A, n = 497; IFNG +874T/A, n = 397), a group of patients with COVID-19 (CoV, n = 222) and among the subgroups of patients with nonsevere (n = 150) and severe (n = 72) COVID-19. We found no significant difference between the genotypic and allelic frequencies of TNF -308G/A in the groups analyzed; however, both the frequencies of the high expression genotype (TT) (CoV: 13.51% vs. CG: 6.30%; p = 0.003) and the *T allele (CoV: 33.56% vs. CG: 24. 81%; p = 0.001) of the IFNG +874T/A polymorphism were higher in the COVID-19 group than in the control group, with no differences between the subgroups of patients with nonsevere and severe COVID-19. The *T allele of IFNG +874T/A (rs2430561) is associated with susceptibility to symptomatic COVID-19. These SNPs provided valuables clues about the potential mechanism involved in the susceptibility to developing symptomatic COVID-19.

The Staphylococcus aureus regulatory program in a human skin-like environment.

Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20%-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like medium (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant Staphylococcus aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted quantitative reverse transcription-PCR (qRT-PCR) experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. This improved adherence to corneocytes was dependent on both acidic pH and growth in SLM. These results support the potential utility of SLM as an in vitro model for assessing staphylococcal physiology and metabolism on human skin. IMPORTANCE: Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed medium that strives to replicate the human skin surface environment and demonstrates roles for adhesins clumping factor A (ClfA), serine-rich repeat glycoprotein adhesin (SraP), and the fibronectin binding proteins (Fnbps) in human corneocyte adherence.

One sixth of Amazonian tree diversity is dependent on river floodplains.

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.

Severe COVID-19 and long COVID are associated with high expression of STING, cGAS and IFN-α.

The cGAS-STING pathway appears to contribute to dysregulated inflammation during coronavirus disease 2019 (COVID-19); however, inflammatory factors related to long COVID are still being investigated. In the present study, we evaluated the association of cGAS and STING gene expression levels and plasma IFN-α, TNF-α and IL-6 levels with COVID-19 severity in acute infection and long COVID, based on analysis of blood samples from 148 individuals, 87 with acute COVID-19 and 61 in the post-COVID-19 period. Quantification of gene expression was performed by real-time PCR, and cytokine levels were quantified by ELISA and flow cytometry. In acute COVID-19, cGAS, STING, IFN-α, TNF-α, and IL-6 levels were higher in patients with severe disease than in those with nonsevere manifestations (p < 0.05). Long COVID was associated with elevated cGAS, STING and IFN-α levels (p < 0.05). Activation of the cGAS-STING pathway may contribute to an intense systemic inflammatory state in severe COVID-19 and, after infection resolution, induce an autoinflammatory disease in some tissues, resulting in long COVID.

Sensitivity and specificity of the EAT-10 and SDQ-DP in identifying the risk of dysphagia in Parkinson's disease.

BACKGROUND: The early identification of risk for dysphagia in patients with Parkinson's disease (PD) is essential for the prevention of nutritional and pulmonary complications. OBJECTIVE: To analyze the sensitivity and specificity of the Swallowing Disturbance Questionnaire (SDQ-PD) and the Eating Assessment Tool (EAT-10) in identifying dysphagia risk in patients with early and intermediate stages of PD. METHODS: Twenty-nine patients with PD participated in the study. EAT-10 and SDQ-PD questionnaires were applied, and a videofluoroscopic swallowing study. Dysphagia Outcome and Severity Scale (DOSS) was used to classify the presence and severity of dysphagia, and the Penetration-Aspiration Scale (PAS) was used to identify the presence of penetration/aspiration. In the statistical analysis, the sensitivity and specificity of the risk questionnaires were calculated, as well as positive predictive value, negative predictive value, and accuracy. RESULTS: EAT-10 to identify the risk of penetration/aspiration revealed a sensitivity of 71.42% and specificity of 45.45%; in the identification of the presence of dysphagia, the sensitivity was 47.61%, and the specificity was 12.5%. The SDQ-PD questionnaire for risk of penetration/aspiration demonstrated a sensitivity of 28.57%, and a specificity of 68.18%. In terms of identifying the presence of dysphagia, the sensitivity was 20%, while the specificity was 44.44%. CONCLUSION: The SDQ-PD revealed low sensitivity and low specificity to identify the presence of dysphagia and/or penetration/aspiration in patients with early and intermediate stages of PD in this sample. Despite its low specificity, the EAT-10 exhibited good sensitivity in indicating the risk of penetration/aspiration.

ANTECEDENTES: A identificação precoce de risco para disfagia nos pacientes com doença de Parkinson (DP) é fundamental para a prevenção de complicações nutricionais e pulmonares. OBJETIVO: Analisar a sensibilidade e especificidade dos questionários Swallowing Disturbance Questionnaire (SDQ-PD) e Eating Assessment Tool (EAT-10) para a identificação do risco de disfagia em pacientes com DP nos estágios iniciais e intermediários da doença. MéTODOS: Participaram 29 pacientes com DP. Foi realizado a aplicação dos questionários EAT-10 e SDQ-PD e o exame de videofluoroscopia da deglutição. Para a classificação da presença e gravidade da disfagia foi utilizada a escala Dysphagia Outcome and Severity Scale e, para identificação da presença de penetração/aspiração, a escala Penetration-Aspiration Scale (PAS). Na análise estatística, calcularam-se a sensibilidade e a especificidade dos questionários de risco EAT-10 e SDQ-DP e o valor preditivo positivo, o valor preditivo negativo e a acurácia. RESULTADOS: A análise do EAT-10 para identificar o risco de penetração/aspiração revelou sensibilidade de 71.42% e especificidade de 45.45%; para identificar a presença de disfagia, a sensibilidade foi de 47,61% e a especificidade de 12.5%. Em relação ao questionário SDQ-PD, para identificar risco de penetração/aspiração, a sensibilidade foi de 28.57% e a especificidade de 68.18% e, para identificar a presença de disfagia, a sensibilidade foi de 20% e a especificidade de 44.44%. CONCLUSãO: O questionário SDQ-PD revelou baixa sensibilidade e baixa especificidade para identificar presença de disfagia e/ou penetração/aspiração em pacientes com DP em estágios iniciais e intermediários para essa amostra. O EAT-10 revelou boa sensibilidade na indicação de risco de penetração/aspiração, apesar de baixa especificidade.

Corrigendum: Assessment of risk scores to predict mortality of COVID-19 patients admitted to the intensive care unit.

[This corrects the article DOI: 10.3389/fmed.2023.1130218.].

Imaging features for the evaluation of skin and nail infections.

Clinical manifestations of dermatological and musculoskeletal conditions can sometimes overlap, leading to confusion in diagnosis. Patients with nail and skin infections may undergo imaging examinations with suspicions of muscle, tendon, or joint injuries. Dermatological infections often involve soft tissues and musculoskeletal structures, and their etiology can range from fungi, bacteria, viruses, to protozoa. Relying solely on physical examination may not be sufficient for accurate diagnosis and treatment planning, necessitating the use of complementary imaging exams. The objective of this paper is to present and discuss imaging findings of the main infectious conditions affecting the nail apparatus and skin. The paper also highlights the importance of imaging in clarifying diagnostic uncertainties and guiding appropriate treatment for dermatological conditions.

Use of adipose derived stem cells accelerates the healing process in third-degree burns.

INTRODUCTION: Burns are defined as a traumatic injury, usually of thermal origin, that affects the epithelial and adjacent tissue and is classified according to the depth reached. Tissue repair involved in this type of injury is often a challenge both due to its severity and the multiplicity of complications. Regenerative medicine has focused on the use of low-level laser photobiomodulation therapy (LLLT) and adipose-derived stem cells (ADSC), especially in the early stages of the process, to promote better healing and shorten repair time. Therefore, aim of this study was to evaluate the action of LLLT (660 nm) and ADSC in the repair process of burned skin tissue and investigate the association of the techniques (LLLT and ADSC). MATERIALS AND METHODS: An in vivo study was carried out using 96 rats (Wister) with a scald burn model at a temperature of 95ºC, exposing the animal's back for 14 s. Animals were randomized into seven groups and three periods, five, 14 and 21 days. The groups included GC: Control group, ADSC-: Group treated with CD49d negative cells, ADSC+ : Group treated with positive CD49d cells, CULT: Group treated with conventional isolation cells, LLLT: Group treated only with LLLT Low Power Laser, ADSC-LLLT: Group treated with CD49d negative cells and LLLT. ADSC+LLLT: Group treated with positive CD49d cells and LLLT. The groups treated with LLLT (660 nm; 5 J/cm2) received irradiation three times a week, on alternate days for five, 14 and 21 days, according to the time of biopsy. ADSC-treated groups received one to three applications of the cells in a total volume of 1000 µL starting soon after the surgical debridement of the burn. Photographic monitoring was carried out at 5, 14 and 21 days after the beginning of the experiment to assess the degree of lesion contraction. Macroscopic, morphometric and histopathological analyzes were performed. RESULTS: We showed significant re-epithelialization as well as an improvement in the healing process in the ADSC+, LLLT and ADSC+LLLT groups. We observed effects in the reduction of the inflammatory phase, increase in angiogenesis, decrease in oedema, greater collagen deposition, and better organization of the extracellular matrix compared to the other treatments. Moreover, the immunomagnetic separation of ADSC cells through the expression of the CD49d protein proved to be a useful means to obtain a more homogeneous population of cells with a role in tissue regeneration compared to the ADSC- and CULT groups. CONCLUSION: In conclusion, the association of ADSC+ with LLLT was effective in accelerating the burn repair process, stimulating cell proliferation and formation of more normal skin tissue.

Sensitivity and specificity of the EAT-10 and SDQ-DP in identifying the risk of dysphagia in Parkinson's disease / Sensibilidade e especificidade do EAT-10 e SDQ-DP na identificação do risco de disfagia na doença de Parkinson

Abstract Background The early identification of risk for dysphagia in patients with Parkinson's disease (PD) is essential for the prevention of nutritional and pulmonary complications. Objective To analyze the sensitivity and specificity of the Swallowing Disturbance Questionnaire (SDQ-PD) and the Eating Assessment Tool (EAT-10) in identifying dysphagia risk in patients with early and intermediate stages of PD. Methods Twenty-nine patients with PD participated in the study. EAT-10 and SDQ-PD questionnaires were applied, and a videofluoroscopic swallowing study. Dysphagia Outcome and Severity Scale (DOSS) was used to classify the presence and severity of dysphagia, and the Penetration-Aspiration Scale (PAS) was used to identify the presence of penetration/aspiration. In the statistical analysis, the sensitivity and specificity of the risk questionnaires were calculated, as well as positive predictive value, negative predictive value, and accuracy. Results EAT-10 to identify the risk of penetration/aspiration revealed a sensitivity of 71.42% and specificity of 45.45%; in the identification of the presence of dysphagia, the sensitivity was 47.61%, and the specificity was 12.5%. The SDQ-PD questionnaire for risk of penetration/aspiration demonstrated a sensitivity of 28.57%, and a specificity of 68.18%. In terms of identifying the presence of dysphagia, the sensitivity was 20%, while the specificity was 44.44%. Conclusion The SDQ-PD revealed low sensitivity and low specificity to identify the presence of dysphagia and/or penetration/aspiration in patients with early and intermediate stages of PD in this sample. Despite its low specificity, the EAT-10 exhibited good sensitivity in indicating the risk of penetration/aspiration.

Resumo Antecedentes A identificação precoce de risco para disfagia nos pacientes com doença de Parkinson (DP) é fundamental para a prevenção de complicações nutricionais e pulmonares. Objetivo Analisar a sensibilidade e especificidade dos questionários Swallowing Disturbance Questionnaire (SDQ-PD) e Eating Assessment Tool (EAT-10) para a identificação do risco de disfagia em pacientes com DP nos estágios iniciais e intermediários da doença. Métodos Participaram 29 pacientes com DP. Foi realizado a aplicação dos questionários EAT-10 e SDQ-PD e o exame de videofluoroscopia da deglutição. Para a classificação da presença e gravidade da disfagia foi utilizada a escala Dysphagia Outcome and Severity Scale e, para identificação da presença de penetração/aspiração, a escala Penetration-Aspiration Scale (PAS). Na análise estatística, calcularam-se a sensibilidade e a especificidade dos questionários de risco EAT-10 e SDQ-DP e o valor preditivo positivo, o valor preditivo negativo e a acurácia. Resultados A análise do EAT-10 para identificar o risco de penetração/aspiração revelou sensibilidade de 71.42% e especificidade de 45.45%; para identificar a presença de disfagia, a sensibilidade foi de 47,61% e a especificidade de 12.5%. Em relação ao questionário SDQ-PD, para identificar risco de penetração/aspiração, a sensibilidade foi de 28.57% e a especificidade de 68.18% e, para identificar a presença de disfagia, a sensibilidade foi de 20% e a especificidade de 44.44%. Conclusão O questionário SDQ-PD revelou baixa sensibilidade e baixa especificidade para identificar presença de disfagia e/ou penetração/aspiração em pacientes com DP em estágios iniciais e intermediários para essa amostra. O EAT-10 revelou boa sensibilidade na indicação de risco de penetração/aspiração, apesar de baixa especificidade.

The potential of galactomannan from Caesalpinia ferrea on erosive dentin wear reduction in vitro.

Gels containing juca seed galactomannan (JSG) were evaluated for their potential to prevent the progression of dentin erosive wear in an in vitro study with four experimental groups (n = 9). The treatments included distilled water (DW), 0.05% stannous fluoride (121 ppm F), and 0.5% or 1% JSG. The specimens underwent a cycle (3 times/day) consisting of immersion in 1% citric acid (5 minutes), treatment (5 minutes), and artificial saliva exposure (2 hours/overnight) for 5 days. Surface changes were assessed using mechanical profilometry (wear), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using ANOVA followed by Tukey's post-test (p < 0.05). The negative control group exhibited the highest wear (6.0 µm ± 3.5), significantly differing from the group treated with 0.05% stannous fluoride gel (p = 0.007), which showed less dentin loss. The groups treated with 0.5% and 1% JSG showed results similar to the negative control (p = 0.661; p = 0.212, respectively) and the stannous fluoride group (p = 0.103; p = 0.379, respectively). In the SEM images, the specimen treated with stannous fluoride showed obliterated tubules, while the JSG gels formed crystals on the dentin surface, as confirmed by the presence of oxygen and calcium in the EDS analysis. Although the JSG gels showed similar results to the stannous fluoride, did not exhibit superior efficacy at the tested concentrations.

The Staphylococcus aureus regulatory program in a human skin-like environment.

Staphylococcus aureus is a Gram-positive pathogen responsible for the majority of skin and soft tissue infections (SSTIs). S. aureus colonizes the anterior nares of approximately 20-30% of the population and transiently colonizes the skin, thereby increasing the risk of developing SSTIs and more serious infections. Current laboratory models that mimic the skin surface environment are expensive, require substantial infrastructure, and limit the scope of bacterial physiology studies under human skin conditions. To overcome these limitations, we developed a cost-effective, open-source, chemically defined media recipe termed skin-like media (SLM) that incorporates key aspects of the human skin surface environment and supports growth of several Staphylococcal species. We utilized SLM to investigate the transcriptional response of methicillin-resistant S. aureus (MRSA) following growth in SLM compared to a commonly used laboratory media. Through RNA-seq analysis, we observed the upregulation of several virulence factors, including genes encoding functions involved in adhesion, proteolysis, and cytotoxicity. To further explore these findings, we conducted qRT-PCR experiments to determine the influence of media composition, pH, and temperature on the transcriptional response of key factors involved in adhesion and virulence. We also demonstrated that MRSA primed in SLM adhered better to human corneocytes and demonstrated adhesin-specific phenotypes that previously required genetic manipulation. These results support the potential utility of SLM as an in vitro model for assessing Staphylococcal physiology and metabolism on human skin. Importance: Staphylococcus aureus is the major cause of skin diseases, and its increased prevalence in skin colonization and infections present a need to understand its physiology in this environment. The work presented here outlines S. aureus upregulation of colonization and virulence factors using a newly developed media that strives to replicate the human skin surface environment, and demonstrates roles for adhesins ClfA, SraP, and Fnbps in human corneocyte adherence.

S. aureus drives itch and scratch-induced skin damage through a V8 protease-PAR1 axis.

Itch is an unpleasant sensation that evokes a desire to scratch. The skin barrier is constantly exposed to microbes and their products. However, the role of microbes in itch generation is unknown. Here, we show that Staphylococcus aureus, a bacterial pathogen associated with itchy skin diseases, directly activates pruriceptor sensory neurons to drive itch. Epicutaneous S. aureus exposure causes robust itch and scratch-induced damage. By testing multiple isogenic bacterial mutants for virulence factors, we identify the S. aureus serine protease V8 as a critical mediator in evoking spontaneous itch and alloknesis. V8 cleaves proteinase-activated receptor 1 (PAR1) on mouse and human sensory neurons. Targeting PAR1 through genetic deficiency, small interfering RNA (siRNA) knockdown, or pharmacological blockade decreases itch and skin damage caused by V8 and S. aureus exposure. Thus, we identify a mechanism of action for a pruritogenic bacterial factor and demonstrate the potential of inhibiting V8-PAR1 signaling to treat itch.

Mapping density, diversity and species-richness of the Amazon tree flora.

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution.

Sugarcane: an unexpected habitat for black yeasts in Chaetothyriales.

Sugarcane (Saccharum officinarum, Poaceae) is cultivated on a large scale in (sub)tropical regions such as Brazil and has considerable economic value for sugar and biofuel production. The plant is a rich substrate for endo- and epiphytic fungi. Black yeasts in the family Herpotrichiellaceae (Chaetothyriales) are colonizers of human-dominated habitats, particularly those rich in toxins and hydrocarbon pollutants, and may cause severe infections in susceptible human hosts. The present study assessed the diversity of Herpotrichiellaceae associated with sugarcane, using in silico identification and selective isolation. Using metagenomics, we identified 5833 fungal sequences, while 639 black yeast-like isolates were recovered in vitro. In both strategies, the latter fungi were identified as members of the genera Cladophialophora, Exophiala, and Rhinocladiella (Herpotrichiellaceae), Cyphellophora (Cyphellophoraceae), and Knufia (Trichomeriaceae). In addition, we discovered new species of Cladophialophora and Exophiala from sugarcane and its rhizosphere. The first environmental isolation of Cladophialophora bantiana is particularly noteworthy, because this species up to now is exclusively known from the human host where it mostly causes fatal brain disease in otherwise healthy patients.

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia.

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.

The potential of galactomannan from Caesalpinia ferrea on erosive dentin wear reduction in vitro

Abstract Gels containing juca seed galactomannan (JSG) were evaluated for their potential to prevent the progression of dentin erosive wear in an in vitro study with four experimental groups (n = 9). The treatments included distilled water (DW), 0.05% stannous fluoride (121 ppm F), and 0.5% or 1% JSG. The specimens underwent a cycle (3 times/day) consisting of immersion in 1% citric acid (5 minutes), treatment (5 minutes), and artificial saliva exposure (2 hours/overnight) for 5 days. Surface changes were assessed using mechanical profilometry (wear), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The data were analyzed using ANOVA followed by Tukey's post-test (p < 0.05). The negative control group exhibited the highest wear (6.0 µm ± 3.5), significantly differing from the group treated with 0.05% stannous fluoride gel (p = 0.007), which showed less dentin loss. The groups treated with 0.5% and 1% JSG showed results similar to the negative control (p = 0.661; p = 0.212, respectively) and the stannous fluoride group (p = 0.103; p = 0.379, respectively). In the SEM images, the specimen treated with stannous fluoride showed obliterated tubules, while the JSG gels formed crystals on the dentin surface, as confirmed by the presence of oxygen and calcium in the EDS analysis. Although the JSG gels showed similar results to the stannous fluoride, did not exhibit superior efficacy at the tested concentrations.

Resumo Géis contendo galactomanana da semente de jucá (GSJ) foram avaliados quanto ao seu potencial na prevenção da progressão do desgaste erosivo dentinário em um estudo in vitro com quatro grupos experimentais (n = 9). Os tratamentos incluíram água destilada (AD), 0,05% de fluoreto de estanho (121 ppm F) e 0,5% ou 1% de GSJ. Os espécimes passaram por um ciclo (3 vezes ao dia) que consistia em imersão em ácido cítrico 1% (5 minutos), tratamento (5 minutos) e exposição a saliva artificial (2 horas/durante a noite) por 5 dias. As alterações de superfície foram avaliadas utilizando perfilometria mecânica (desgaste), microscopia eletrônica de varredura (MEV) e espectroscopia de raios-X por dispersão de energia (EDS). Os dados foram analisados por ANOVA, seguida do pós-teste de Tukey (p < 0,05). O grupo controle negativo apresentou o maior desgaste (6,0 µm ± 3,5), diferindo significativamente do grupo tratado com gel de fluoreto de estanho a 0,05% (p = 0,007), que apresentou menor perda de dentina. Os grupos tratados com 0,5% e 1% de GSJ apresentaram resultados semelhantes ao grupo controle negativo (p = 0,661; p = 0,212, respectivamente) e ao grupo de fluoreto de estanho (p = 0,103; p = 0,379, respectivamente). Nas imagens de MEV, o espécime tratado com fluoreto de estanho mostrou túbulos obliterados, enquanto os géis GSJ formaram cristais na superfície da dentina, como confirmado pela presença de oxigênio e cálcio na análise de EDS. Embora os géis GSJ tenham apresentado resultados semelhantes ao fluoreto de estanho, eles não demonstraram eficácia superior nas concentrações testadas.