Recent publications
Despite the progress in the measurement and accessibility of plant trait information, acquiring sufficiently complete data from enough species to answer broad‐scale questions in plant functional ecology and biogeography remains challenging. A common way to overcome this challenge is by imputation, or ‘gap‐filling' of trait values. This has proven appropriate when focusing on the overall patterns emerging from the database being imputed. However, some applications force the imputation procedure out of its original scope, using imputed values independently from the imputation context, and specific trait values for a given species are used as input for computing new variables. We tested the performance of three widely used imputation methods (Bayesian hierarchical probabilistic matrix factorization, multiple imputation by chained equations with predictive mean matching, and Rphylopars) on a database of tropical tree and shrub traits. By applying a leave‐one‐out procedure, we assessed the accuracy and precision of the imputed values and found that out‐of‐context use of imputed values may bias the estimation of different variables. We also found that low redundancy (i.e. low predictability of a new value on the basis of existing values) in the dataset, not uncommon for empirical datasets, is likely the main cause of low accuracy and precision in the imputed values. We therefore suggest the use of a leave‐one‐out procedure to test the quality of the imputed values before any out‐of‐context application of the imputed values, and make practical recommendations to avoid the misuse of imputation procedures. Furthermore, we recommend not publishing gap‐filled datasets, publishing instead only the empirical data, together with the imputation method applied and the corresponding script to reproduce the imputation. This will help avoid the spread of imputed data, whose accuracy, precision, and source are difficult to assess and track, into the public domain.
Background
Rapidly progressive dementia (RPD) is a group of neurological diseases, where three etiologies are particularly relevant: neurodegenerative, prion and autoimmune encephalitis (AIE) diseases.
Objective
The aim of this study is to conduct a systematic review and meta-analysis of the frequency of these etiologies causing RPD in worldwide and Latin America (LatAm).
Methods
A systematic review and meta-analysis were conducted. A bibliographic search of publications related to the etiologies of RPD was done. The etiologies, the timeframe definition (<1 year versus <2 years) and the study's place of origin were analyzed.
Results
A total of 10 articles were selected for the analysis in this study (n = 1006 patients). Three studies were originated in LatAm cohorts (two from Argentina and one from Brazil). The global prevalence of RPD due to neurodegenerative disease was 23% CI95% [11%; 42%]; prion diseases, 16% CI95% [9%; 28%]; and AIE, 12% CI95% [6%; 22%]. Comparing each overall proportion of etiologies of LatAm versus non-LatAm there were statistically significant differences for AIE (25% versus 8%, respectively, p < 0.01). In the case of timeframe definitions, the comparison of the etiological percentage did not show statistically significant differences.
Conclusions
From our results, approximately a half of the causes of RPD were due to neurodegenerative, prion, and AIE diseases. Future studies will be needed to analyze this issue both globally and regionally.
Proton-coupled electron transfer (PCET) is a common reaction in biological systems, with potential implications for DNA damage and repair. This study showed that tris-(2-pyridine carboxylate) chromium (III) (complex 1) exhibited an increased electrochemical reaction rate in the presence of a strong acid, suggesting that PCET via proton donation promotes the reduction reaction. Conversely, complex 1 with picolinic acid showed a decreased electrochemical exchange constant, suggesting kinetic control by slow electronic exchange, consistent with PCET. Bis(pyridine-2,6-dicarboxylate) chromate (III) of sodium (complex 2), showed potential shifts and broadening of signals in the presence of dipicolinic and ascorbic acids, further supporting the involvement of PCET. Overall, the study highlighted the modulation of the electrochemical behavior of the chromium complexes through proton-coupled shifts in reduction potentials and kinetics, shedding light on their potential interactions with cellular reductant agents and protons. The weaker interactions of complexes 1 and 2 with BSA and DNA, together with their lower bioavailability and solubility compared to CQDP, contribute to our understanding of the potential biological effects of the chromium complexes studied. This abstract provides a comprehensive overview of the results of the study, highlighting the significance of the PCET reactions and their potential implications for biological processes and health effects.
Repetitive elements are the main components of many plant genomes and play a crucial role in the variation of genome size and structure, ultimately impacting species diversification and adaptation. Alstroemeriaceae exhibits species with large genomes, not attributed to polyploidy. In this study, we analysed the repetitive fraction of the genome of Bomarea edulis through low-coverage sequencing and in silico characterization, and compared it to the repeats of Alstroemeria longistaminea, a species from a sister genus that has been previously characterized. LTR-retrotransposons were identified as the most abundant elements in the B. edulis genome (50.22%), with significant variations in abundance for specific lineages between the two species. The expansion of the B. edulis genome was likely due to three main lineages of LTR retrotransposons, Ty3/gypsy Tekay and Retand and Ty1/copia SIRE, all represented by truncated elements which were probably active in the past. Furthermore, the proportion of satDNA (~ 7%) was six times higher in B. edulis compared to A. longistaminea, with most families exhibiting a dispersed, uniform distribution in the genome. SatDNAs, thus, contributed to some extent to genome obesity. Despite diverging around 29 Mya, both species still share some satDNA families and retrotransposons. However, differences in repeat abundances and sequence variants led to genome differentiation despite their similar sizes and structure.
Tissue-repair regulatory T cells (trTregs) comprise a specialized cell subset essential for tissue homeostasis and repair. While well-studied in sterile injury models, their role in infection-induced tissue damage and antimicrobial immunity is less understood. We investigated trTreg dynamics during acute Trypanosoma cruzi infection, marked by extensive tissue damage and strong CD8+ immunity. Unlike sterile injury models, trTregs significantly declined in secondary lymphoid organs and non-lymphoid target tissues during infection, correlating with systemic and local tissue damage, and downregulation of function-associated genes in skeletal muscle. This decline was linked to decreased systemic IL-33 levels, a key trTreg growth factor, and promoted by the Th1 cytokine IFN-γ. Early recombinant IL-33 treatment increased trTregs, type 2 innate lymphoid cells, and parasite-specific CD8+ cells at specific time points after infection, leading to reduced tissue damage, lower parasite burden, and improved disease outcome. Our findings not only provide novel insights into trTregs during infection but also highlight the potential of optimizing immune balance by modulating trTreg responses to promote tissue repair while maintaining effective pathogen control during infection-induced injury.
We conducted experimental pollinations, controlled visits, and observed pollinators’ behaviour to identify activity supporting Cucurbita maxima var. zapallito fruit production. We predict that (a) stigmas artificially pollinated with pinned native bees (Eucera fervens) will have more pollen grains and will produce heavier commercial fruits than those pollinated with exotic bees (Apis mellifera); (b) the differences in fruit weight between the native and exotic bees are expected to increase with the intensity of artificial pollination; (c) controlling E. fervens visits in natural pollination will show fruit trends similar to artificial pollination. Unlike A. mellifera, E. fervens reached flowers by contacting stigmas or the anthers with their abdomen, depositing more pollen grains (> 80) than A. mellifera. Artificial pollination treatments with the two pinned-bee types resulted in fruits of similar weights regardless of pollination intensity. Conversely, in natural pollination, weight differences were observed when the number of visits increased. E. fervens provided at least 132 pollen grains with > 3 visits: the threshold necessary for producing commercial fruits. The visitation frequency registered exceeded this minimum reaching one visit every 10 min. Other factors, such as pollination date and plant, influenced fruit production. Few visits are enough for obtaining commercial fruits: being an immature fruit, squash does not require seed development, besides species with separate flowers developed strategies to achieve rapid pollen saturation. Squash crops rely on the ecological pollination service provided by bees underscoring the conservation value of native bee species.
Concerns over malnutrition, synthetic additives and post-harvest waste highlight the need for innovation in food technology, turning towards underutilized crops. Plant-based beverages offer sustainable dietary alternatives and the increasing demand for such products makes the exploration of native crops particularly relevant. This study focuses on the development of a beverage derived from the native South American fruit kurugua (Sicana odorifera), combined with chia oil (Salvia hispanica L.) and stevia (Stevia rebaudiana Bertoni) as a natural sweetener, aiming to provide a nutritious, environmentally friendly option with appealing sensory attributes. The beverage was formulated using whole kurugua fruit flour (WKF) and chia oil (CO). Comprehensive analyses of the physicochemical properties, centesimal composition, caloric value, minerals, amino acid profile, and fatty acid content revealed that the beverage is rich in carbohydrates (2.16 ± 0.11 g/100 mL), dietary fiber (1.89 ± 0.04 g/100 mL), zinc (2.53 ± 0.16 mg/100 mL), polyunsaturated fatty acids (2.39 g/100 mL), AA (Glu + Gln, 248 g AA/g of WKF and WKCOB-L protein and 168 mg AA/ g of WKCOB protein/100 mL) and exhibits strong antioxidant activity. This is the first report on a product enriched with essential fatty acids with totally natural ingredients based on kurugua and chia oil, which has potential in healthy and vegan nutrition. This formulation supports the sustainable use and conservation of kurugua, offering a high-nutrient alternative for diets.
The focus of this work was to evaluate the differences between the thermal and mechanical effects generated by ultrasound waves on the properties of corn starch, which facilitate the subsequent enzymatic hydrolysis for the generation of porous starches. The results showed that both the thermal and mechanical effects have the capacity to disorganize/alter the structure of starch, impacting on its properties. Characteristics such as particle size, pasting and thermal properties (peak viscosity 1400–1800 cp. and gelatinization enthalpy 4.5–11 J/g) of starch and water absorption were the most affected, while crystallinity was practically unmodified (crystallinity % 23–25). The thermal effect induced by the ultrasound treatment caused most of the alterations in the properties of corn starch. It was associated with the partial gelatinization of the material due to an increase in the system’s temperature (up to 65° C). The effect of the mechanical phenomenon of the treatment by ultrasound waves contributed to a lesser extent compared to the thermal effect. The mechanical effect can extend over time, without the aggravating factor of causing starch gelatinization. The combination of both effects could synergistically modify the granular structure of starch. In conclusion, ultrasound waves as a pre-treatment to enzymatic hydrolysis can cause structural disorganization of starch granules and facilitate the subsequent enzymatic attack for the production of porous starches.
Background and Aims
An expansion of fat mass is an integral feature of patients with heart failure and preserved ejection fraction (HFpEF). While body mass index (BMI) is the most common anthropometric measure, a measure of central adiposity—the waist-to-height ratio (WHtR)—focuses on body fat content and distribution; is not distorted by bone or muscle mass, sex, or ethnicity; and may be particularly relevant in HFpEF.
Methods
The PARAGON-HF trial randomized 4796 patients with heart failure and ejection fraction ≥45% to valsartan or sacubitril/valsartan. The current work characterizes the association of BMI and WHtR with clinical features, outcomes, and the response to neprilysin inhibition.
Results
About half (49%) of the participants were considered obese by BMI (≥30 kg/m2), but nearly every patient (96%) had central adiposity (WHtR ≥0.5). Among patients who were not obese (BMI <30 kg/m2), 860 (37%) had marked central adiposity (WHtR ≥0.6). Higher BMI and WHtR were both associated with higher risk of total heart failure hospitalizations, but as compared with BMI, WHtR was linearly associated with heart failure outcomes and identified a higher proportion of patients who had a particularly elevated risk (i.e., 30% or greater). An obesity-survival paradox (i.e., improved outcomes in those with greater adiposity) was apparent with BMI in unadjusted analyses, but it was not observed with WHtR. Although neprilysin inhibition appeared to have greater effects on heart failure outcomes in patients with higher BMI and WHtR, analyses of interaction with obesity metrics did not show significant heterogeneity across the range of values for adiposity.
Conclusions
In PARAGON-HF, in contrast with BMI, nearly every patient with HFpEF had central adiposity (as assessed by WHtR), and the risks of adverse heart failure events were more robustly related to WHtR. These data challenge the current reliance on BMI as an appropriate metric of adiposity, and they suggest that—rather than obesity-related HFpEF being regarded as a select HFpEF subgroup—central adiposity is a ubiquitous feature of HFpEF.
Increasing soil organic carbon (SOC) in agroecosystems is a key objective for enhancing agricultural sustainability and mitigating climate change. Arbuscular mycorrhizal fungi (AMF) can increase yield and provide several other ecosystem services. Still, studies conducted in agricultural soils have shown that their effects on SOC can be either positive, neutral or negative. In this study, we conducted a quantitative review of the literature to evaluate the role of AMF in influencing SOC across various crop species and conditions.
Through a systematic search of publications, we compiled a dataset comprising 62 trials from 19 studies including field and pot experiments that directly manipulated the mycorrhizal status of plants. We conducted a meta‐analysis to quantitatively evaluate the role of AMF on SOC across several crop species and conditions.
We found an overall positive effect of AMF on SOC, with an average increase of 21.5%. However, this positive effect was statistically significant only in pot experiments whereas in field experiments, the effect was mainly modulated by texture and organic matter content. The effect of AMF on SOC did not vary with crop species' functional type, AMF inoculation sources (single or mixed AMF species) or other soil variables considered.
Our results highlight the significant potential for AMF‐mediated mechanisms to promote SOC accumulation in agricultural soils, although this effect is context‐dependent. However, future research with different approaches and scales is needed to evaluate the impact of AMF on SOC dynamics in agricultural systems and elucidate the mechanisms behind their contribution to SOC accrual.
Read the free Plain Language Summary for this article on the Journal blog.
Current food systems face critical challenges, including biodiversity loss, environmental degradation, and failure to meet global nutritional needs. Indigenous Peoples and Local Communities (IPLCs) are vital in addressing these issues through their local ecological knowledge and diverse use of local food plants. Ethnobotanical research provides insights into sustainable biodiversity management and resilient food systems. The Atlantic Forest (AF), a South American biodiversity hotspot with over 20,000 plant species (40% endemic), exemplifies the importance of preserving biocultural diversity. This review synthesizes data from 89 studies, documenting 6654 use-reports (UR) of 731 plant species used across 10 cultural groups and ecoregions. These include native (e.g., Eugenia uniflora, Psidium guajava, Manihot esculenta) and introduced species (e.g., Citrus spp., Carica papaya, Zea mays). Cultivated plants dominate food use; however, native wild plants are essential, especially in rural areas, for their contributions to dietary diversity, ecological functions, and cultural heritage. Among the many significant families, Myrtaceae, with 71 species (63 native), is notable for its diversity, ecological importance, and cultural integration. Nearly half of the species are unique to specific communities and ecoregions, highlighting the need for further documentation in less-explored areas. The findings underscore the value of traditional ecological knowledge in biodiversity conservation worldwide and call for integrating IPLC knowledge into sustainable management strategies to address the environmental and social challenges threatening the AF’s biocultural diversity.
The swimming motility of bacteria is driven by the action of bacterial flagellar motors, whose outermost structure is a long and thin helicoidal filament. When rotated, the fluid medium exerts an anisotropic viscous drag on the flagellar filaments, ultimately leading to bacterial propulsion. The flagellar filaments are protein-based flexible structures that can break due to interactions with fluid flows. Here, we study the evolution of flagellar filaments in the soil bacterium Bradyrhizobium diazoefficiens after being exposed to shear flows created in long microchannels, for shear rates between 1 and 105 s−1, and for durations between tens of milliseconds and minutes. We demonstrate that the average swimming speed and fraction of swimming cells decrease after exposition to shear, but both parameters can recover, at least partially, with time. These observations support the hypothesis that shear flows cut flagellar filaments but that reversibly damaged bacterial flagellar motors can be restored, thanks to filament regeneration. By fitting our observations with phenomenological expressions, we obtain the individual growth rates of the two different flagellar filaments that B. diazoefficiens possesses, showing that the lateral filaments have a recovery time of about 40 min while the subpolar one requires more than 4.5 h to regrow. Our work demonstrates that simple monitoring of bacterial motility after exposition to shear can be used to characterize the process of flagellar filament breakup and growth, a phenomenon widely present in bacteria swimming in porous soil and exposed to shear flows due to rainfall and watering systems.
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