Pterosaurs were the first vertebrates to evolve powered flight
and comprised one of the main evolutionary radiations in terrestrial ecosystems of the Mesozoic era (approximately 252-66 million years ...ago), but their origin has remained an unresolved enigma in palaeontology since the nineteenth century
. These flying reptiles have been hypothesized to be the close relatives of a wide variety of reptilian clades, including dinosaur relatives
, and there is still a major morphological gap between those forms and the oldest, unambiguous pterosaurs from the Upper Triassic series. Here, using recent discoveries of well-preserved cranial remains, microcomputed tomography scans of fragile skull bones (jaws, skull roofs and braincases) and reliably associated postcrania, we demonstrate that lagerpetids-a group of cursorial, non-volant dinosaur precursors-are the sister group of pterosaurs, sharing numerous synapomorphies across the entire skeleton. This finding substantially shortens the temporal and morphological gap between the oldest pterosaurs and their closest relatives and simultaneously strengthens the evidence that pterosaurs belong to the avian line of archosaurs. Neuroanatomical features related to the enhanced sensory abilities of pterosaurs
are already present in lagerpetids, which indicates that these features evolved before flight. Our evidence illuminates the first steps of the assembly of the pterosaur body plan, whose conquest of aerial space represents a remarkable morphofunctional innovation in vertebrate evolution.
The lower Maastrichtian site of Basturs Poble (southern Pyrenees, Spain) is the first hadrosaur bonebed reported from Europe. It is an accumulation of disarticulated lambeosaurine skeletal elements, ...possibly belonging to Pararhabdodon isonensis. The sample shows high intraspecific morphological variability among many skeletal elements, suggesting the need for caution in choosing characters for phylogenetic analyses. Juvenile to adult individuals are represented in the sample, while hatchling remains are absent. Bone histology reveals that juveniles are over-represented and that the youngest individuals represented by tibia specimens were two years old. Adult individuals, with tibiae 550-600 mm long, were 14-15 years old when they died. However, individual variation in tibia length at skeletal maturity occurs within the sample, so individual maturity cannot be assumed on the basis of bone size alone. The Basturs Poble bonebed occurs within the upper part of the C31r magnetochron. Thus, lambeosaurine hadrosaurids were already present and abundant in the Ibero-Armorica Island at the end of the early Maastrichtian and P. isonensis spans the upper part of the lower Maastrichtian to the upper part of the upper Maastrichtian (upper part of C31r-lower part of C29r).
Heteropelta boboi
is a new archosauriform reptile from the upper Anisian of northeastern Italy represented by a fragment of dorsal armor with a row of neural arches of the dorsal vertebrae. The ...dorsal armor of the new taxon is composed of two columns of paramedian osteoderms and at least six columns of lateral osteoderms. Unlike other armored archosaurs, the osteoderms are imbricated with the posterior osteoderm overlapping the anterior one. The low neural arches bear small neural spines and long postzygapophyses. The osteoderms of the lateral columns increase in size and change in shape from the most medial to the most lateral columns. Among the Archosauriformes, only the non-archosaur proterochampsians
Vancleavea campi
,
Litorosuchus somnii
, and the doswelliids have dorsal armor comprised of more than two columns of osteoderms per side, but the morphology and arrangement of their osteoderms is unlike those of the new Italian taxon. A cladistic analysis of Archosauromorpha positions
Heteropelta boboi
as either a basal phytosaur or a basal suchian. However, a second cladistic analysis focused on armored archosaurs alternatively positions the new taxon as a basal archosauriform, basal suchian, basal loricatan or crocodylomorph. Better resolution of the phylogenetic relationships of
Heteropelta boboi
will likely be obtained only with the discovery of cranial and postcranial remains associated with its diagnostic armor elements.
is an iconic African dinosaur taxon that has been described on the basis of two nearly complete skeletons from the Lower Cretaceous Gadoufaoua locality of the Ténéré desert in Niger. The entire ...holotype and a few bones attributed to the paratype formed the basis of the original description by Taquet (1976). A mounted skeleton that appears to correspond to
has been on public display since 1975, exhibited at the Natural History Museum of Venice. It was never explicitly reported whether the Venice specimen represents a paratype and therefore, the second nearly complete skeleton reported in literature or a third unreported skeleton. The purpose of this paper is to disentangle the complex history of the various skeletal remains that have been attributed to
(aided by an unpublished field map of the paratype) and to describe in detail the osteology of the Venice skeleton. The latter includes the paratype material (found in 1970 and collected in 1972), with the exception of the left femur, the right coracoid and one manus ungual phalanx I, which were replaced with plaster copies, and (possibly) other manus phalanges. Some other elements (e.g., the first two chevrons, the right femur, the right tibia, two dorsal vertebrae and some pelvic bones) were likely added from other individual/s. The vertebral column of the paratype was articulated and provides a better reference for the vertebral count of this taxon than the holotype. Several anatomical differences are observed between the holotype and the Venice specimen. Most of them can be ascribed to intraspecific variability (individual or ontogenetic), but some are probably caused by mistakes in the preparation or assemblage of the skeletal elements in both specimens. The body length of the Venice skeleton is about 90% the linear size of the holotype. Osteohistological analysis (the first for this taxon) of some long bones, a rib and a dorsal neural spine reveals that the Venice specimen is a sub-adult; this conclusion is supported by somatic evidence of immaturity. The dorsal 'sail' formed by the elongated neural spines of the dorsal, sacral and proximal caudal vertebrae characterizes this taxon among ornithopods; a display role is considered to be the most probable function for this bizarre structure. Compared to the mid-1970s, new information from the Venice specimen and many iguanodontian taxa known today allowed for an improved diagnosis of
Biosensors based on Förster resonance energy transfer (FRET) have revolutionized cellular biology by allowing the direct measurement of biochemical processes in situ. Many genetically encoded ...sensors make use of fluorescent proteins that are limited in spectral versatility and that allow few ways to change the spectral properties once the construct has been created. In this work, we developed genetically encoded FRET biosensors based on the chemigenetic SNAP and HaloTag domains combined with matching organic fluorophores. We found that the resulting constructs can display comparable responses, kinetics, and reversibility compared to their fluorescent protein-based ancestors, but with the added advantage of spectral versatility, including the availability of red-shifted dye pairs. However, we also find that the introduction of these tags can alter the sensor readout, showing that careful validation is required before applying such constructs in practice. Overall, our approach delivers an innovative methodology that can readily expand the spectral variety and versatility of FRET-based biosensors.
Information concerning the longevity of immunity to SARS-CoV-2 following natural infection may have considerable implications for durability of immunity induced by vaccines. Here, we monitored the ...SARS-CoV-2 specific immune response in COVID-19 patients followed up to 15 months after symptoms onset. Following a peak at day 15–28 postinfection, the IgG antibody response and plasma neutralizing titers gradually decreased over time but stabilized after 6 months. Compared to G614, plasma neutralizing titers were more than 8-fold lower against variants Beta, Gamma, and Delta. SARS-CoV-2-specific memory B and T cells persisted in the majority of patients up to 15 months although a significant decrease in specific T cells, but not B cells, was observed between 6 and 15 months. Antiviral specific immunity, especially memory B cells in COVID-19 convalescent patients, is long-lasting, but some variants of concern may at least partially escape the neutralizing activity of plasma antibodies.
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•Plasma neutralizing antibodies persist in the majority of patients up to 15 months•Neutralizing activity is lower against variants of concern Delta, Beta, and Gamma•Specific memory B and T cells were present in 95% of patients up to 15 months•Specific T cells, but not B cells, were decreased between 6 and 15 months
Immunology; Immune response; Virology
A small accumulation of bones from the Norian (Upper Triassic) of the Seazza Brook Valley (Carnic Prealps, Northern Italy) was originally (1989) identified as a gastric pellet made of pterosaur ...skeletal elements. The specimen has been reported in literature as one of the very few cases of gastric ejecta containing pterosaur bones since then. However, the detailed analysis of the bones preserved in the pellet, their study by X-ray microCT, and the comparison with those of basal pterosaurs do not support a referral to the Pterosauria. Comparison with the osteology of a large sample of Middle-Late Triassic reptiles shows some affinity with the protorosaurians, mainly with Langobardisaurus pandolfii that was found in the same formation as the pellet. However, differences with this species suggest that the bones belong to a similar but distinct taxon. The interpretation as a gastric pellet is confirmed.
The commitment of multidisciplinary teams in antimicrobial stewardship programs (ASPs) is often inadequately considered, especially in surgical wards. We wanted to evaluate clinical, microbiological, ...and pharmacological outcomes before and after the implementation of an ASP in the Vascular Surgery ward of Fondazione IRCCS Policlinico San Matteo, a tertiary care hospital in Pavia, Italy.
This was a quasi-experimental quality-improvement study. The antimicrobial stewardship activity was conducted twice a week for 12 months and consisted of both prospective audit and feedback of all the ongoing antimicrobial prescriptions by the infectious diseases' consultants and educational meetings for the healthcare workers of the Vascular Surgery ward. For comparison between the study periods, Student t test (Mann-Whitney test for skewed distributions) was used for quantitative variables (ANOVA or Kruskall-Wallis for > 2 groups respectively), and Pearson's chi-squared test (Fisher exact test where appropriate) for categorical variables. 2-tailed tests were used. P-value significance cut-off was 0.05.
During the 12-month intervention period, among a total number of 698 patients, 186 prescriptions were revised, mostly leading to de-escalating an ongoing antimicrobial therapy (39, 20.97%). A statistically significant reduction in isolates of carbapenem-resistant Pseudomonas aeruginosa (p-value 0.003) and the absence of Clostridioides difficile infections were reported. No statistically significant changes were observed in terms of length of stay and all-cause in-hospital mortality. A significant decrease in the administration of carbapenems (p-value 0.01), daptomycin (p-value < 0.01) and linezolid (p-value 0.43) was registered. A significant reduction in antimicrobial costs was also observed.
The implementation of a 12-month ASP brought significant clinical and economic results, highlighting the benefits of a multidisciplinary teamwork.
•In COVID19-associated respiratory failure, lung transplantation might be an option;•Sars-CoV2 infection was recognized as a cause of HLH in severe COVID19 cases;•Post-Covid cholangiopathy is ...described as a new clinical entity;•The treatments for HLH can increase the risk of infection of transplant recipients.
Sars-CoV2 can cause severe pneumonia and acute respiratory distress syndrome (ARDS). In COVID-19-associated respiratory failure, lung transplantation might be an option (Bharat A).
A previously healthy 63-year-old man with a nasopharyngeal swab positive for SarsCoV2 and radiological evidence of interstitial lung consolidations developed acute respiratory distress that required intubation and veno-venous extracorporeal membrane oxygenation support (VV ECMO). Because of no recovery of his lung function, he underwent a bilateral lung transplant. ICU stay was complicated by several episodes of bacterial superinfections and an increase of liver function tests (LFTs). Afterward, he faced a progressive clinical worsening associated to severe anemia, further rise of indices of cholestasis, hypertriglyceridemia and hyperferritinemia. Bone marrow smear showed a picture compatible with haemophagocytic lymphohistocytosis (HLH) and first and second line therapy were started. In addition, a transjugular hepatic biopsy was performed with histopathological evidence of portal and periportal fibrosis, compatible with Covid 19-related cholangiopathy. During the hospital stay, he developed several MDR opportunistic infections. The patient died few months later from multiorgan failure secondary to septic shock. A post-mortem confirmed a diagnosis of cholangiopathy, and medullary erythro-haemophagocytosis.
Post Covid19 syndrome is a clinical entity that includes novel and old sequelae following recovery from Sars-CoV2 infections. Early identification of these diseases is crucial for adequate management and might influence the long term prognosis of these patients.
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