The pre-eminent role of directional selection in generating extreme morphological change in glyptodonts (Cingulata; Xenarthra).

The prevalence of stasis on macroevolution has been classically taken as evidence of the strong role of stabilizing selection in constraining morphological change. Rates of evolution calculated over longer timescales tend to fall below the expected under genetic drift, suggesting that directional selection signals are erased at longer timescales. Here, we investigated the rates of morphological evolution of the skull in a fossil lineage that underwent extreme morphological modification, the glyptodonts. Contrary to what was expected, we show here that directional selection was the primary process during the evolution of glyptodonts. Furthermore, the reconstruction of selection patterns shows that traits selected to generate a glyptodont morphology are markedly different from those operating on extant armadillos. Changes in both direction and magnitude of selection are probably tied to glyptodonts' invasion of a specialist-herbivore adaptive zone. These results suggest that directional selection might have played a more critical role in the evolution of extreme morphologies than previously imagined.

Selection and Constraints in the Ecomorphological Adaptive Evolution of the Skull of Living Canidae (Carnivora, Mammalia).

The association between phenotype and ecology is essential for understanding the environmental drivers of morphological evolution. This is a particularly challenging task when dealing with complex traits, such as the skull, where multiple selective pressures are at play and evolution might be constrained by ontogenetic and genetic factors. I integrate morphometric tools, comparative methods, and quantitative genetics to investigate how ontogenetic constraints and selection might have interacted during the evolution of the skull in extant Canidae. The results confirm that the evolution of cranial morphology was largely adaptive and molded by changes in diet composition. While the investigation of the adaptive landscape reveals two main selective lines of least resistance (one associated with size and one associated with functional shape features), rates of evolution along size were higher than those found for shape dimensions, suggesting the influence of constraints on morphological evolution. Structural modeling analyses revealed that size, which is the line of most genetic/phenotypic variation, might have acted as a constraint, negatively impacting dietary evolution. Constraints might have been overcome in the case of selection for the consumption of large prey by associating strong selection along both size and shape directions. The results obtained here show that microevolutionary constraints may have played a role in shaping macroevolutionary patterns of morphological evolution.

High evolutionary constraints limited adaptive responses to past climate changes in toad skulls.

Interactions among traits that build a complex structure may be represented as genetic covariation and correlation. Genetic correlations may act as constraints, deflecting the evolutionary response from the direction of natural selection. We investigated the relative importance of drift, selection, and constraints in driving skull divergence in a group of related toad species. The distributional range of these species encompasses very distinct habitats with important climatic differences and the species are primarily distinguished by differences in their skulls. Some parts of the toad skull, such as the snout, may have functional relevance in reproductive ecology, detecting water cues. Thus, we hypothesized that the species skull divergence was driven by natural selection associated with climatic variation. However, given that all species present high correlations among skull traits, our second prediction was of high constraints deflecting the response to selection. We first extracted the main morphological direction that is expected to be subjected to selection by using within- and between-species covariance matrices. We then used evolutionary regressions to investigate whether divergence along this direction is explained by climatic variation between species. We also used quantitative genetics models to test for a role of random drift versus natural selection in skull divergence and to reconstruct selection gradients along species phylogeny. Climatic variables explained high proportions of between-species variation in the most selected axis. However, most evolutionary responses were not in the direction of selection, but aligned with the direction of allometric size, the dimension of highest phenotypic variance in the ancestral population. We conclude that toad species have responded to selection related to climate in their skulls, yet high evolutionary constraints dominated species divergence and may limit species responses to future climate change.

Morphological integration during postnatal ontogeny: implications for evolutionary biology.

How covariance patterns of phenotypes change during development is fundamental for a broader understanding of evolution. There is compelling evidence that mammalian cranium covariance patterns change during ontogeny. However, it is unclear to what extent variation in covariance patterns during ontogeny can impact the response to selection. To tackle this question, we explored: (a) the extent to which covariance patterns change during postnatal ontogeny; (b) in which ontogenetic stages covariance patterns differ the most; and (c) the extent to which the phenotypic covariance pattern at different ontogenetic stages can be explained by the same processes determining additive genetic covariance. We sampled the postnatal ontogenetic series for both marsupials and placentals. Within each ontogenetic series, we compared covariance matrices (P-matrices) at different ontogenetic stages. Furthermore, we compared these P-matrices to two target matrices [adult P-matrix and an additive genetic covariance matrix (G-matrix)]. Our results show that for all ontogenetic series, covariance patterns from weaning onward are conserved and probably shaped by the same processes determining the G-matrix. We conclude that irrespective of eventual differences in how selection operates during most of the postnatal ontogeny, the net response to such pressures will probably not be affected by ontogenetic differences in the covariance pattern.

Rules of teeth development align microevolution with macroevolution in extant and extinct primates.

Macroevolutionary biologists have classically rejected the notion that higher-level patterns of divergence arise through microevolutionary processes acting within populations. For morphology, this consensus partly derives from the inability of quantitative genetics models to correctly predict the behaviour of evolutionary processes at the scale of millions of years. Developmental studies (evo-devo) have been proposed to reconcile micro- and macroevolution. However, there has been little progress in establishing a formal framework to apply evo-devo models of phenotypic diversification. Here we reframe this issue by asking whether using evo-devo models to quantify biological variation can improve the explanatory power of comparative models, thus helping us bridge the gap between micro- and macroevolution. We test this prediction by evaluating the evolution of primate lower molars in a comprehensive dataset densely sampled across living and extinct taxa. Our results suggest that biologically informed morphospaces alongside quantitative genetics models allow a seamless transition between the micro- and macroscales, whereas biologically uninformed spaces do not. We show that the adaptive landscape for primate teeth is corridor like, with changes in morphology within the corridor being nearly neutral. Overall, our framework provides a basis for integrating evo-devo into the modern synthesis, allowing an operational way to evaluate the ultimate causes of macroevolution.

Evaluation of the antiproliferative activity of the leaves from Arctium lappa by a bioassay-guided fractionation.

Arctium lappa L. (Asteraceae) is used in folk medicine around the World, and shows several kinds of biological activity, particularly in vitro antitumor activity in different cell lines. This study evaluated the antiproliferative activity of the crude extract, semipurified fractions, and isolated compounds from the leaves of A. lappa, through bioassay-guided testing in Caco-2 cells. The crude extract was obtained with a 50% hydroethanolic extract and then partitioned with hexane, ethyl acetate, and n-butanol. The ethyl-acetate fraction (EAF) showed antiproliferative activity. This fraction was subjected to sequential column chromatography over silica gel to afford onopordopicrin (1), mixtures of 1 with dehydromelitensin-8-(4'-hydroxymethacrylate) (2), a mixture of 2 with dehydromelitensin (3), mixture of 1 with melitensin (4), dehydrovomifoliol (5), and loliolide (6). The compounds were identified by spectroscopic methods (NMR, MS) and comparison with literature data. This is the first description of compounds 2-5 from this species. The compounds tested in Caco-2 cells showed the following CC(50) (µg/mL) values: 1: 19.7 ± 3.4, 1 with 2: 24.6 ± 1.5, 2 with 3: 27 ± 11.7, 1 with 4: 42 ± 13.1, 6 30 ± 6.2; compound 5 showed no activity.

A common mechanism drives the alignment between the micro- and macroevolution of primate molars.

A central challenge for biology is to reveal how different levels of biological variation interact and shape diversity. However, recent experimental studies have indicated that prevailing models of evolution cannot readily explain the link between micro- and macroevolution at deep timescales. Here, we suggest that this paradox could be the result of a common mechanism driving a correlated pattern of evolution. We examine the proportionality between genetic variance and patterns of trait evolution in a system whose developmental processes are well understood to gain insight into how such alignment between morphological divergence and genetic variation might be maintained over macroevolutionary time. Primate molars present a model system by which to link developmental processes to evolutionary dynamics because of the biased pattern of variation that results from the developmental architecture regulating their formation. We consider how this biased variation is expressed at the population level, and how it manifests through evolution across primates. There is a strong correspondence between the macroevolutionary rates of primate molar divergence and their genetic variation. This suggests a model of evolution in which selection is closely aligned with the direction of genetic variance, phenotypic variance, and the underlying developmental architecture of anatomical traits.

Evaluation of Antioxidant Potential of Commercial Cinnamon Samples and Its Vasculature Effects.

Growing concerns on free radicals are the oxidative processes associated with physiological damage. The consumption of functional foods and use of plants with antioxidant capacity are widespread. Given the importance of determining antioxidant capacity in relation to the therapeutic effect, this study was aimed at evaluating cinnamon extract (Cinnamomum sp.) in commercial samples by spectrophotometric and voltammetric methods and assessing the vascular activity of some samples. The spectrophotometric methods performed were DPPH (1,1-diphenyl-2-picrihydrazine), ABTS (2,21-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)), and Folin-Ciocalteu radical sequestration assays. For the electrochemical experiments, a three-electrode system was used, consisting of carbon paste electrode, platinum wire, and Ag/AgCl/KClsat, representing the working, auxiliary, and reference electrodes, respectively. The electroanalytical methods used were differential pulse, square wave, and cyclic voltammetries. The extracts were prepared in hydroalcoholic solution. A calibration curve with gallic acid was calculated to quantify their equivalent amounts in the analyzed extract. The correlation between the electrochemical approach and the total phenols calculated by the ABTS, DPPH, and Folin-Ciocalteu methods was 0.63, 0.7, and 0.73, respectively, with 1 being an ideal directly proportional correlation. The correlation between spectrophotometric methods was 0.83. A biosensor was developed in a carbon paste electrode using the enzyme laccase, obtained by the fungus Marasmiellus colocasiae. It was observed that the antioxidant profile of the cinnamon samples had an analytical sign improvement of up to 4 times when compared with the electrode without the modification. The samples were analyzed by mass spectrometer, and the main chemical markers found were coumarin, cinnamaldehyde, and eugenol. Pharmacological trials showed that these samples also induce a significant vasorelaxant effect associated to antioxidant potential on vascular injury induced by oxidative stress. Thus, cinnamon showed a high antioxidant capacity, in agreement with the results obtained in other studies, emphasizing its importance as a functional food.

Electroanalytical Enzyme Biosensor Based on Cordia superba Enzyme Extract for the Detection of Phytomarkers in Kombucha.

Antioxidants are responsible for many beneficial health effects and are highly present in natural products, such as kombucha. Biosensors' development targeting antioxidants and phytomarkers are an active research field. This work aimed to propose a voltammetric polyphenolxidase (Cordia superba) biosensor for catechin and total phenolic compounds quantification in kombucha samples. Optimizations were performed on the biosensor of Cordia superba to improve the accuracy and selectivity, such as enzyme-substrate interaction time, analytical responses for different patterns and signal differences with the carbon paste and modified carbon paste electrode. Kombucha probiotic drink samples were fermented for 7 to 14 days at a controlled temperature (28 ± 2 °C). A linear curve was made for catechin with a range of 10.00 to 60.00 µM, with a limit of detection of 0.13 µM and limit of quantification of 0.39 µM. The biosensor proposed in this work was efficient in determining the patterns of phenolic compounds in kombucha.

Prevalence of renal involvement among pediatric patients hospitalized due to coronavirus disease 2019: A multicenter study. / Prevalencia de compromiso renal en pacientes pediátricos internados con enfermedad por coronavirus 2019: estudio multicéntrico.

INTRODUCTION: Renal involvement among pediatric patients with coronavirus disease 2019 (COVID-19) ranges between 1.2% and 44%. Given the limited information available locally, the primary objective of this study was to estimate the prevalence of renal involvement in our setting. POPULATION AND METHODS: Cross-sectional study conducted in 13 Argentine sites between March and December 2020. Patients aged 1 month to 18 years hospitalized due to COVID-19 and with at least one measurement of serum creatinine and/or a urinalysis were included. Those with a known kidney disease were excluded. Renal involvement was defined as the presence of acute kidney injury (AKI), proteinuria, hematuria, leukocyturia and/or arterial hypertension (HTN). RESULTS: Among 528 eligible medical records, 423 patients were included (55.0% were males; median age: 5.3 years). The clinical presentation was asymptomatic in 31%; mild, in 39.7%; moderate, in 23.9%; severe, in 1.2%; critical, in 0.7%; and 3.5% had multisystem inflammatory syndrome in children (MIS-C). Two patients (0.47%) died. The prevalence of renal involvement was 10.8% (95% confidence interval: 8.2-14.2); it was described as leukocyturia (16.9%), proteinuria (16.0%), hematuria (13.2%), HTN (3.7%), and AKI (2.3%). No patient required dialysis. Renal involvement was associated with severe forms of disease (p < 0.0001). CONCLUSIONS: The prevalence of renal involvement among pediatric patients hospitalized due to COVID-19 in 13 Argentine sites was 10.8%; severe forms of disease prevailed.

Introducción. El compromiso renal (CR) en niños internados con enfermedad por coronavirus 2019 (COVID-19, por su sigla en inglés) varía entre el 1,2 % y el 44 %. Dado que existe limitada información local, el objetivo primario de este estudio fue estimar la prevalencia de CR en nuestro medio. Población y métodos. Estudio transversal realizado en 13 centros de Argentina entre marzo y diciembre de 2020. Se incluyeron pacientes internados con COVID-19, de 1 mes a 18 años y que tuvieran al menos una determinación de creatinina sérica y/o de orina completa. Se excluyeron aquellos con enfermedad renal conocida. Se consideró CR la presencia de lesión renal aguda (LRA), proteinuria, hematuria, leucocituria y/o hipertensión arterial (HTA). Resultados. De 528 historias clínicas elegibles, se incluyeron las de 423 pacientes (el 55,0 % de sexo masculino, mediana de edad 5,3 años). El cuadro clínico fue asintomático en el 31 %, leve en el 39,7 %, moderado en el 23,9 %, grave en el 1,2 %, crítico en el 0,7 %, y el 3,5 % presentó síndrome inflamatorio multisistémico pediátrico (SIMP). Dos pacientes (0,47 %) fallecieron. La prevalencia de CR fue del 10,8 % (intervalo de confianza 95% 8,2-14,2), expresada por leucocituria (16,9 %), proteinuria (16,0 %), hematuria (13,2 %), HTA (3,7 %) y LRA (2,3 %). Ninguno requirió diálisis. Presentar CR se asoció (p <0,0001) con formas graves de enfermedad. Conclusión. La prevalencia de CR en pacientes pediátricos internados con COVID-19 en 13 centros de nuestro país fue del 10,8 % y predominó en las formas clínicas graves.

Enzymatic Electroanalytical Biosensor Based on Maramiellus colocasiae Fungus for Detection of Phytomarkers in Infusions and Green Tea Kombucha.

In this work, we developed an enzymatic voltammetric biosensor for the determination of catechin and gallic acid in green tea and kombucha samples. The differential pulse voltammetry (DPV) methodology was optimized regarding the amount of crude enzyme extract, incubation time in the presence of the substrates, optimal pH, reuse of the biosensor, and storage time. Samples of green tea and kombucha were purchased in local markets in the city of Goiânia-GO, Brazil. High performance liquid chromatography (HPLC) and Folin-Ciocalteu spectrophotometric techniques were performed for the comparison of the analytical methods employed. In addition, two calibration curves were made, one for catechin with a linear range from 1 to 60 µM (I = -0.152 * (catechin) - 1.846), with a detection limit of 0.12 µM and a quantification limit of 0.38 µM and one for gallic acid with a linear range from 3 to 60 µM (I = -0.0415 * (gallic acid) - 0.0572), with a detection limit of 0.14 µM and a quantification limit of 0.42 µM. The proposed biosensor was efficient in the determination of phenolic compounds in green tea.

Coding behavioural data for cladistic analysis: using dynamic homology without parsimony.

Many of the controversies around the concept of homology rest on the subjectivity inherent to primary homology propositions. Dynamic homology partially solves this problem, but there has been up to now scant application of it outside of the molecular domain. This is probably because morphological and behavioural characters are rich in properties, connections and qualities, so that there is less space for conflicting character delimitations. Here we present a new method for the direct optimization of behavioural data, a method that relies on the richness of this database to delimit the characters, and on dynamic procedures to establish character state identity. We use between-species congruence in the data matrix and topological stability to choose the best cladogram. We test the methodology using sequences of predatory behaviour in a group of spiders that evolved the highly modified predatory technique of spitting glue onto prey. The cladogram recovered is fully compatible with previous analyses in the literature, and thus the method seems consistent. Besides the advantage of enhanced objectivity in character proposition, the new procedure allows the use of complex, context-dependent behavioural characters in an evolutionary framework, an important step towards the practical integration of the evolutionary and ecological perspectives on diversity. © The Willi Hennig Society 2010.

Cardiopulmonary effects of matching positive end-expiratory pressure to abdominal pressure in concomitant abdominal hypertension and acute lung injury.

BACKGROUND: To evaluate the cardiopulmonary effects of positive end-expiratory pressure (PEEP) equalization to intra-abdominal pressure (IAP) in an experimental model of intra-abdominal hypertension (IAH) and acute lung injury (ALI). METHODS: Eight anesthetized pigs were submitted to IAH of 20 mm Hg with a carbon dioxide insufflator for 30 minutes and then submitted to lung lavage with saline and Tween (2.5%). Pressure x volume curves of the respiratory system were performed by a low flow method during IAH and ALI, and PEEP was subsequently adjusted to 27 cm . H2O for 30 minutes. RESULTS: IAH decreases pulmonary and respiratory system static compliances and increases airway resistance, alveolar-arterial oxygen gradient, and respiratory dead space. The presence of concomitant ALI exacerbates these findings. PEEP identical to AP moderately improved oxygenation and respiratory mechanics; however, an important decline in stroke index and right ventricle ejection fraction was observed. CONCLUSIONS: Simultaneous IAH and ALI produce important impairments in the respiratory physiology. PEEP equalization to AP may improve the respiratory performance, nevertheless with a secondary hemodynamic derangement.

Electroanalysis Applied to Compatibility and Stability Assays of Drugs: Carvedilol Study Case.

Carvedilol (CRV) is a non-selective blocker of α and ß adrenergic receptors, which has been extensively used for the treatment of hypertension and congestive heart failure. Owing to its poor biopharmaceutical properties, CRV has been incorporated into different types of drug delivery systems and this necessitates the importance of investigating their compatibility and stability. In this sense, we have investigated the applicability of several electroanalytical tools to assess CRV compatibility with lipid excipients. Voltammetric and electrochemical impedance spectroscopy techniques were used to evaluate the redox behavior of CRV and lipid excipients. Results showed that Plurol® isostearic, liquid excipient, and stearic acid presented the greatest anode peak potential variation, and these were considered suitable excipients for CRV formulation. CRV showed the highest stability at room temperature and at 50 °C when mixed with stearic acid (7% w/w). The results also provided evidence that electrochemical methods might be feasible to complement standard stability/compatibility studies related to redox reactions.

Measuring the magnitude of morphological integration: The effect of differences in morphometric representations and the inclusion of size.

The magnitude of morphological integration is a major aspect of multivariate evolution, providing a simple measure of the intensity of association between morphological traits. Studies concerned with morphological integration usually translate phenotypes into morphometric representations to quantify how different morphological elements covary. Geometric and classic morphometric representations translate biological form in different ways, raising the question if magnitudes of morphological integration estimates obtained from different morphometric representations are compatible. Here we sought to answer this question using the relative eigenvalue variance of the covariance matrix obtained for both geometric and classical representations of empirical and simulated datasets. We quantified the magnitude of morphological integration for both shape and form and compared results between representations. Furthermore, we compared integration values between shape and form to evaluate the effect of the inclusion or not of size on the quantification of the magnitude of morphological integration. Results show that the choice of morphological representation has significant impact on the integration magnitude estimate, either for shape or form. Despite this, ordination of the integration values within representations is relatively the same, allowing for similar conclusions to be reached using different methods. However, the inclusion of size in the dataset significantly changes the estimates of magnitude of morphological integration, hindering the comparison of this statistic obtained from different spaces. Morphometricians should be aware of these differences and must consider how biological hypothesis translate into predictions about integration in each particular choice of representation.

Electrochemical Characterization of Central Action Tricyclic Drugs by Voltammetric Techniques and Density Functional Theory Calculations.

This work details the study of the redox behavior of the drugs cyclobenzaprine (CBP), amitriptyline (AMP) and nortriptyline (NOR) through voltammetric methods and computational chemistry. Results obtained in this study show that the amine moiety of each compound is more likely to undergo oxidation at 1a at Ep1a ≈ 0.69, 0.79, 0.93 V (vs. Ag/AgCl/KClsat) for CBP, AMP and NOR, respectively. Moreover, CBP presented a second peak, 2a at Ep2a ≈ 0.98 V (vs. Ag/AgCl/KClsat) at pH 7.0. Furthermore, the electronic structure calculation results corroborate the electrochemical assays regarding the HOMO energies of the lowest energy conformers of each molecule. The mechanism for each anodic process is proposed according to electroanalytical and computational chemistry findings, which show evidence that the methods herein employed may be a valuable alternative to study the redox behavior of structurally similar drugs.

Evolution of morphological integration in the skull of Carnivora (Mammalia): Changes in Canidae lead to increased evolutionary potential of facial traits.

Morphological integration refers to the fact that different phenotypic traits of organisms are not fully independent from each other, and tend to covary to different degrees. The covariation among traits is thought to reflect properties of the species' genetic architecture and thus can have an impact on evolutionary responses. Furthermore, if morphological integration changes along the history of a group, inferences of past selection regimes might be problematic. Here, we evaluated the stability and evolution of the morphological integration of skull traits in Carnivora by using evolutionary simulations and phylogenetic comparative methods. Our results show that carnivoran species are able to respond to natural selection in a very similar way. Our comparative analyses show that the phylogenetic signal for pattern of integration is lower than that observed for morphology (trait averages), and that integration was stable throughout the evolution of the group. That notwithstanding, Canidae differed from other families by having higher integration, evolvability, flexibility, and allometric coefficients on the facial region. These changes might have allowed canids to rapidly adapt to different food sources, helping to explain not only the phenotypic diversification of the family, but also why humans were able to generate such a great diversity of dog breeds through artificial selection.

Cranial adaptations for feeding on snails in species of Sibynomorphus (Dipsadidae: Dipsadinae).

Neotropical "goo-eating" dipsadine snakes display a set of morphological and histo-chemical adaptations linked to the capture of their soft-bodied, viscous invertebrate prey. Within this group, species from the genus Sibynomorphus feed chiefly on snails and slugs. Here, we analyzed a series of skull and mandible characters in S. mikanii, S. neuwiedi and S. turgidus using geometric morphometrics, with the aim of assessing morphological adaptations related to slug- and snail-feeding in that genus. We further compared the results with Leptodeira annulata, a species that feeds on vertebrates. To evaluate shape differences of the skull and mandible between species we performed a multivariate analysis of variance and a linear discriminant analysis. Our results show that the narrow, elongate skull in S. mikanii may help with slug ingestion, while asymmetry in teeth number and mandibular shape in S. neuwiedi and S. turgidus are likely related to snail feeding.