‘Dinosaur-bird’ macroevolution, locomotor modules and the origins of flight

S.M.N. is supported by a FPI-UAM 2019 predoctoral grant from the Autonomous University of Madrid. This research was partially funded by project CGL2013-42643P from MINECO (Spain) and PGC2018-094955-A100 from MICIU (Spain). This work is a contribution of the CIPb-UAM research group and the PMMV team (Paleoclimatology, Macroecology and Macroevolution of Vertebrates) as part of the UCM-910607 research group. We thank to all the organizing committee of the 4th International Meeting of Early-stage Researchers in Palaeontology for inviting us to participate in the Special Issue “Young Solutions to Old Issues: Discoveries in Palaeontology Research”. Funding Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Natu

Changes in the free-energy landscape of p38α MAP kinase through its canonical activation and binding events as studied by enhanced molecular dynamics simulations

p38α is a Ser/Thr protein kinase involved in a variety of cellular processes and pathological conditions, which makes it a promising pharmacological target. Although the activity of the enzyme is highly regulated, its molecular mechanism of activation remains largely unexplained, even after decades of research. By using state-of-the-art molecular dynamics simulations, we decipher the key elements of the complex molecular mechanism refined by evolution to allow for a fine tuning of p38α kinase activity. Our study describes for the first time the molecular effects of different regulators of the enzymatic activity, and provides an integrative picture of the activation mechanism that explains the seemingly contradictory X-ray and NMR data

Brote de eritema infeccioso en un centro de salud urbano

ObjetivosAnalizar las características clínicas y serológicas de un brote de eritema infeccioso en pacientes que acudieron a las 2 consultas de pediatría del Centro de Salud de Soria Norte.DiseñoEstudio descriptivo, transversal.EmplazamientoConsultas de pediatría del Centro de Salud de Soria Norte.PacientesUna vez sospechado el brote, se estudiaron niños con clínica sugestiva de eritema infeccioso que acudieron sucesivamente a las 2 consultas de pediatría de Soria Norte durante los meses de abril a agosto de 1998 y consintieron en la práctica de analítica.IntervencionesSe realizó registro de síntomas clínicos, serología, hemograma y evolución de 25 pacientes.ResultadosSe estudiaron 25 pacientes del total de casos, confirmando nuestra sospecha diagnóstica en un 84% de los casos. No se observaron diferencias en ambos sexos, con una edad media de 6,1 años, y DE, 2,015. El signo clínico más constante fue el exantema en mejillas, presente en un 100% de los casos confirmados, seguido de exantema en tronco y extremidades en un 57,1%, adenopatías en un 9,5% y fiebre en un 4,7%. En ningún caso se objetivaron complicaciones.ConclusionesLos resultados de este trabajo permiten confirmar la existencia de un brote de eritema infeccioso en nuestro medio. Consideramos útil la confirmación serológica para constatar la presencia de un brote y poder realizar un enfoque terapéutico (frente a complicaciones posibles) y preventivo adecuado. Destacamos el carácter, en general, benigno de la enfermedad.ObjectivesTo analyse the clinical and serological characteristics of an outbreak of infectious erythema in patients attending the two paediatrics clinics at the Soria Norte Health Centre.DesignCross-sectional, descriptive study.SettingPaediatrics clinics of the Soria Norte Health Centre.PatientsOnce the outbreak was suspected, the study was conducted on children with a clinical picture suggesting infectious erythema who attended successively two Soria Norte paediatrics clinics between April and August 1998 and who consented to the analyses.InterventionsThe clinical symptoms, serology, haemogram and evolution of 25 patients were recorded.Results25 patients of the total were studied and diagnostic suspicion was confirmed in 84% of the cases. There were no differences between sexes, with an average age of 6.1, SD 2.015. The most constant clinical sign was exanthem on the cheeks, present in 100% of the cases confirmed, followed by 57% exanthem on the trunk and limbs, 9.5% adenopathies and 4.7% temperature. No complications were found in any case.ConclusionsThe results of this study confirm the existence of an outbreak of infectious erythema in our area. Serological confirmation of an outbreak is useful and can lay the basis for a proper therapeutic and preventive focus (against possible complications). We highlight the generally benign nature of the disease

Quantitative analysis of morphometric data of pre-modern birds: phylogenetic versus ecological signal

Birds are one of the most diverse clades of extant terrestrial vertebrates, a diversity that first arose during the Mesozoic as a multitude of lineages of pre-neornithine (stem) birds appeared but did not survive into the Cenozoic Era. Modern birds (Neornithes) inhabit an extensive array of ecologically distinct habitats and have specific and varied foraging strategies. Likewise, the morphological disparity among Mesozoic lineages appears to underscore a significant degree of ecological diversity, yet attempts to determine lineage specific ecologies have mainly been limited to superficial narratives. In recent years, numerous studies have used various morphometric proxies to interpret the paleoecology of Mesozoic bird lineages, but largely without evaluating the interplay between ecological and phylogenetic signals. Moreover, most studies of this sort transform the original data into logarithms to control dimensionality, underestimating the biases induced upon such transformations. The goal of this study is to quantitatively address the ecomorphology of crown-group Neornithes using a dense sample of raw forelimb and hindlimb measurements, and to examine if such results can be used to infer the ecologies of Mesozoic bird lineages. To that end, scaling of limb measurements and ecological data from modern birds was assessed statistically using phylogenetic comparative methods, followed by the inclusion of fossil taxa. A strong relationship was recovered between humerus and hindlimb allometric scaling and phylogeny. Our results indicate that while some ecological classes of modern birds can be discriminated from each other, phylogenetic signature can overwhelm ecological signal in morphometric data, potentially limiting the inferences that can be made from ecomorphological studies. Furthermore, we found differential scaling of leg bones among Early Cretaceous enantiornithines and ornithuromorphs, a result hinting that habitat partitioning among different lineages could be a pervasive phenomenon in avian evolutio

Identification of new and unusual rev and nef transcripts expressed by an HIV type 1 primary isolate

We analyzed RNA splice site usage in three HIV-1 subtype B primary isolates through reverse transcriptase polymerase chain reaction (RT-PCR) amplification of spliced RNAs using a fluorescently labeled primer, with computerized size determination and quantification of PCR products, which were also identified by clone sequencing. In one isolate, P2149-3, unusual and unreported spliced transcripts were detected. This isolate preferentially used for rev RNA generation a 3' splice site (3'ss) located five nucleotides upstream of A4a, previously identified only in a T cell line-adapted virus and in a group O isolate, and designated A4d. P2149-3 also used an unreported 3'ss for rev RNA generation, designated A4h, located 20 nucleotides upstream of 3'ss A4c. Additionally, unusual nef RNAs using 3'ss A5a and A7a and with exon composition 1.3.7 were identified. The identification of several unusual and unreported spliced transcripts in an HIV-1 primary isolate suggests a greater diversity of splice site usage in HIV-1 than previously appreciated.We thank the personnel at the Genomic Unit of Centro Nacional de Microbiología, Instituto de Salud Carlos III, for technical assistance in sequencing and GeneMapper analyses. This work was funded by Ministerio de Economía y Competitividad (Spain), Plan Nacional de I+D+I, through grants SAF2007-61688 and SAF2010-2096. Sequences of PCR clones derived from P2149-3 DS transcripts have been deposited in GenBank under accession numbers JF808039–JF808078

The preliminary lattice QCD calculation of κ\kappa meson decay width

We present a direct lattice QCD calculation of the $\kappa$ meson decay width with the s-wave scattering phase shift for the isospin $I=1/2$ pion-kaon ($\pi K$) system. We employ a special finite size formula, which is the extension of the Rummukainen-Gottlieb formula for the $\pi K$ system in the moving frame, to calculate the scattering phase, which indicates a resonance around $\kappa$ meson mass. Through the effective range formula, we extract the effective $\kappa \to \pi K$ coupling constant $g_{\kappa \pi K} = 4.54(76)$ GeV and decay width $\Gamma = 293 \pm 101$ MeV. Our simulations are done with the MILC gauge configurations with $N_f=2+1$ flavors of the "Asqtad" improved staggered dynamical sea quarks on a $16^3\times48$ lattice at $(m_\pi + m_K) / m_\kappa \approx 0.8$ and lattice spacing $a \approx 0.15$ fm.Comment: To make it concise. arXiv admin note: text overlap with arXiv:1110.1422, but much of v1 text overlap with articles by same and other authors remove

A theropod trackway providing evidence of a pathological foot from the exceptional locality of Las Hoyas (upper Barremian, Serranía de Cuenca, Spain)

We describe a trackway (LH-Mg-10-16) occurring in laminated carbonated limestones of the Las Hoyas locality, Serranía de Cuenca, Spain. It is unmistakably a large theropod dinosaur trackway encompassing two unusual aspects, namely, wide-steps, and a set of equally deformed left footprints (with a dislocated digit). The layer also preserves other vertebrate trails (fish Undichna) and different impressions in the sediment. To address these complex settings, we devised a multidisciplinary approach, including the ichnological and taphonomical descriptions, characterisation of the rock lithofacies using thin-sections, 3D structured-light digitalisation with a high precision of 200-400 μm, and a geometric morphometric comparison with a large sample of bipedal dinosaur trackways. Sedimentary analyses showed that the trackway was produced in a humid, benthonic microbial mat, the consistency and plasticity of which enabled the preservation of the details of the movement of the animal. The results of the geometric analysis indicate that the 'wide-steps' of the trackway is not unusual compared to other trackways, providing evidence that it was made by a single individual with an estimated hip height approximately 2 m. Analogous pathologies in extant archosaurs that yield the combination of wide steps and deformed digits in the same trackway were considered. All results mutually support the hypothesis that a large theropod dinosaur, with a pathological foot, generated the trackway as it crossed an area of shallow water while slowly walking towards the main water source, thus stepping steadily over the benthonic mat over which multiple fish were swimming

Structural basis of a redox-dependent conformational switch that regulates the stress kinase p38α

Many functional aspects of the protein kinase p38α have been illustrated by more than three hundred structures determined in the presence of reducing agents. These structures correspond to free forms and complexes with activators, substrates, and inhibitors. Here we report the conformation of an oxidized state with an intramolecular disulfide bond between Cys119 and Cys162 that is conserved in vertebrates. The structure of the oxidized state does not affect the conformation of the catalytic site, but alters the docking groove by partially unwinding and displacing the short αD helix due to the movement of Cys119 towards Cys162. The transition between oxidized and reduced conformations provides a mechanism for fine-tuning p38α activity as a function of redox conditions, beyond its activation loop phosphorylation. Moreover, the conformational equilibrium between these redox forms reveals an unexplored cleft for p38α inhibitor design that we describe in detail.© 2023. The Author(s)

Craniofacial development illuminates the evolution of nightbirds (Strisores)

Evolutionary variation in ontogeny played a central role in the origin of the avian skull. However, its influence in subsequent bird evolution is largely unexplored. We assess the links between ontogenetic and evolutionary variation of skull morphology in Strisores (nightbirds). Nightbirds span an exceptional range of ecologies, sizes, life-history traits and craniofacial morphologies constituting an ideal test for evo-devo hypotheses of avian craniofacial evolution. These morphologies include superficially 'juvenile-like' broad, flat skulls with short rostra and large orbits in swifts, nightjars and allied lineages, and the elongate, narrow rostra and globular skulls of hummingbirds. Here, we show that nightbird skulls undergo large ontogenetic shape changes that differ strongly from widespread avian patterns. While the superficially juvenile-like skull morphology of many adult nightbirds results from convergent evolution, rather than paedomorphosis, the divergent cranial morphology of hummingbirds originates from an evolutionary reversal to a more typical avian ontogenetic trajectory combined with accelerated ontogenetic shape change. Our findings underscore the evolutionary lability of cranial growth and development in birds, and the underappreciated role of this aspect of phenotypic variability in the macroevolutionary diversification of the amniote skull

Diversidad de enemigos naturales de pulgones en cultivos de lechuga

Este trabajo ha sido subvencionado por la beca predoctoral del Ministerio de Ciencia y Tecnología: AGL2003-0753-C03-01 y forma parte de la Tesis Doctoral de I. Morales (BES-2004-5217)