A well preserved skeleton of the fossil shark Cosmopolitodus hastalis from the late Miocene of Peru, featuring fish remains as fossilized stomach contents

Both the preservation of the poorly mineralized skeleton of sharks and the preservation of stomach contents are rarely observed in the fossil record. Here we report on a partial skeleton of a lamniform shark, including portions of the visceral arches and the anterior segment of the vertebral column, collected from the late Miocene beds of the Pisco Formation exposed at Cerro Yesera (Ica Desert, South Peru). Based on the morphology of the preserved teeth, this specimen was determined as a juvenile of the extinct lamnid species Cosmopolitodus hastalis. The shark skeleton includes remains of fish (featuring a pilchard determined as Sardinops sp. cf. S. sagax) in the abdominal region. These fish remains are interpreted herein as the fossilized stomach contents of the shark. For the first time, piscivory is demonstrated in a juvenile individual of Cosmopolitodus hastalis. This result is consistent with the current knowledge about the feeding habits of immature individuals of extant lamniform shark species (including Carcharodon carcharias and Isurus oxyrinchus). Our report further outlines the fundamental role of schooling pilchards in the late Miocene trophic chains of the highly productive coastal waters off present South Peru. Moreover, the find of this well preserved shark skeleton strengthens the qualification of the Pisco Formation as a Fossil-Lagerstätte, and emphasizes the role of early mineralization processes in cases of exceptional preservation

A rhinopristiform sawfish (Genus pristis) from the middle eocene (lutetian) of southern Peru and its regional implications

Modern sawfishes (Rhinopristiformes: Pristidae) are circumglobally distributed in warm waters and are common in proximal marine and even freshwater habitats. The fossil record of modern pristid genera (i.e., Pristis and Anoxypristis) dates back to the early Eocene and is mostly represented by isolated rostral spines and oral teeth, with phosphatised rostra representing exceptional occurrences. Here, we report on a partial pristid rostrum, exhibiting several articulated rostral spines, from middle Eocene strata of the Paracas Formation (Yumaque Member) exposed in the southern Peruvian East Pisco Basin. This finely preserved specimen shows anatomical structures that are unlikely to leave a fossil record, e.g., the paracentral grooves that extend along the ventral surface of the rostrum. Based on the morphology of the rostral spines, this fossil sawfish is here identified as belonging to Pristis. To our knowledge, this discovery represents the geologically oldest known occurrence of Pristidae from the Pacific Coast of South America. Although the fossil record of pristids from the East Pisco Basin spans from the middle Eocene to the late Miocene, sawfishes are no longer present in the modern cool, upwelling-influenced coastal waters of southern Peru. Given the ecological preferences of the extant members of Pristis, the occurrence of this genus in the Paracas deposits suggests that middle Eocene nearshore waters in southern Peru were warmer than today. The eventual disappearance of pristids from the coastal waters off southern Peru might be interpreted as reflecting the late Cenozoic trend of strengthening of the Humboldt Current

Stray light evaluation for the astrometric gravitation probe mission

The main goal of the Astrometric Gravitation Probe mission is the verification of General Relativity and competing gravitation theories by precise astrometric determination of light deflection, and of orbital parameters of selected Solar System objects. The key element is the coherent combination of a set of 92 circular entrance apertures, each feeding an elementary inverted occulter similar to the one developed for Solar Orbiter/METIS.1 This provides coronagraphic functions over a relevant field of view, in which all stars are observed for astrometric purposes with the full resolution of a 1 m diameter telescope. The telescope primary mirror acts as a beam combiner, feeding the 92 pupils, through the internal optics, toward a single focal plane. The primary mirror is characterized by 92 output apertures, sized according to the entrance pupil and telescope geometry, in order to dump the solar disk light beyond the instrument. The astronomical objects are much fainter than the solar disk, which is angularly close to the inner field of view of the telescope. The stray light as generated by the diffraction of the solar disk at the edges of the 92 apertures defines the limiting magnitude of observable stars. In particular, the stray light due to the diffraction from the pupil apertures is scattered by the telescope optics and follows the same optical path of the astronomical objects; it is a contribution that cannot be eliminated and must therefore be carefully evaluated. This paper describes the preliminary evaluation of this stray light contribution

AGP (Astrometric Gravitation Probe) optical design report

This paper describes the current opto-mechanical design of AGP, a mission designed for astrometric verification of General Relativity (GR) and competing gravitation theories by means of precise determination of light deflection on field stars, and of orbital parameters of selected Solar System objects. The optical concept includes a planar rear-view mirror for simultaneous imaging on the CCD mosaic detector of fields of view also from the direction opposite to the Sun, affected by negligible deflection, for the sake of real time calibration. The precision of astrometric measurements on individual stars will be of order of 1 mas, over two fields separated by few degrees around the Sun and observed simultaneously. We describe the optical design characteristics, with particular reference to manufacturing and tolerancing aspects, evidencing the preservation of very good imaging performance over the range of expected operating conditions

Higher 90-Day Mortality after Surgery for Hip Fractures in Patients with COVID-19: A Case-Control Study from a Single Center in Italy

The mortality of hip fracture (HF) patients is increased by concomitant COVID-19; however, evidence is limited to only short follow-up. A retrospective matched case-control study was designed with the aim to report the 90-day mortality and determine the hazard ratio (HR) of concomitant HF and COVID-19 infection. Cases were patients hospitalized for HF and diagnosed with COVID-19. Controls were patients hospitalized for HF not meeting the criteria for COVID-19 diagnosis and were individually matched with each case through a case-control (1:3) matching algorithm. A total of 89 HF patients were treated during the study period, and 14 of them were diagnosed as COVID-19 positive (overall 15.7%). Patients' demographic, clinical, and surgical characteristics were similar between case and control groups. At 90 days after surgery, 5 deaths were registered among the 14 COVID-19 cases (35.7%) and 4 among the 42 HF controls (9.5%). COVID-19-positive cases had a higher risk of mortality at 30 days (HR = 4.51; p = 0.0490) and 90 days (HR = 4.50; p = 0.025) with respect to controls. Patients with concomitant HF and COVID-19 exhibit high perioperative mortality, which reaches a plateau of nearly 30-35% after 30 to 45 days and is stable up to 90 days. The mortality risk is more than four-fold higher in patients with COVID-19

Nuevo espécimen de Carcharodon hastalis (Lamniformes Lamnidae) en sedimentitas de la Formación Pisco: evidencias de su paleoecología trófica

En los últimos años, los registros de vertebrados fósiles con preservación excepcional expuestos en la cuenca Pisco, se han incrementado notablemente (Clarke et al., 2010; Lambert et al., 2010, 2015; Bianucci et al., 2010, 2014; Stucchi et al., 2016 entre otros) y los afloramientos de la Formación Pisco han puesto en evidencia no solo una amplia diversidad de taxones fósiles asociados sino además, una fosilización excepcional que la distingue de otras formaciones en diferentes latitudes. El presente trabajo, como producto de la actualización de la Carta Geológica Nacional, se suma a los hallazgos concernientes a los seláceos fósiles y amplia el registro nacional limitado mayormente a sus dientes. Para el presente caso, se pone en evidencia un esqueleto fósil parcial que conserva además de las mandíbulas y algunos dientes, los discos vertebrales articulados e incluso parte de lo que se infiere como su contenido estomacal consistente en sardinas fósiles (Sardinops sp.). El hallazgo fue realizado en el cerro Yesera en la margen izquierda del río Ica, al SO de la localidad de Callango, distrito de Ocucaje, departamento de Ica (Figura 1). Estratigráficamente corresponde a niveles de la Formación Pisco, y en tiempo correspondería a niveles del Mioceno superior (aprox. 9 Ma). La sistemática paleontológica utilizada sigue a lo propuesto por Ehret et al., (2012

Comparison and combination of a hemodynamics/biomarkers-based model with simplified PESI score for prognostic stratification of acute pulmonary embolism: findings from a real world study

Background: Prognostic stratification is of utmost importance for management of acute Pulmonary Embolism (PE) in clinical practice. Many prognostic models have been proposed, but which is the best prognosticator in real life remains unclear. The aim of our study was to compare and combine the predictive values of the hemodynamics/biomarkers based prognostic model proposed by European Society of Cardiology (ESC) in 2008 and simplified PESI score (sPESI).Methods: Data records of 452 patients discharged for acute PE from Internal Medicine wards of Tuscany (Italy) were analysed. The ESC model and sPESI were retrospectively calculated and compared by using Areas under Receiver Operating Characteristics (ROC) Curves (AUCs) and finally the combination of the two models was tested in hemodinamically stable patients. All cause and PE-related in-hospital mortality and fatal or major bleedings were the analyzed endpointsResults: All cause in-hospital mortality was 25% (16.6% PE related) in high risk, 8.7% (4.7%) in intermediate risk and 3.8% (1.2%) in low risk patients according to ESC model. All cause in-hospital mortality was 10.95% (5.75% PE related) in patients with sPESI score ≥1 and 0% (0%) in sPESI score 0. Predictive performance of sPESI was not significantly different compared with 2008 ESC model both for all cause (AUC sPESI 0.711, 95% CI: 0.661-0.758 versus ESC 0.619, 95% CI: 0.567-0.670, difference between AUCs 0.0916, p=0.084) and for PE-related mortality (AUC sPESI 0.764, 95% CI: 0.717-0.808 versus ESC 0.650, 95% CI: 0.598-0.700, difference between AUCs 0.114, p=0.11). Fatal or major bleedings occurred in 4.30% of high risk, 1.60% of intermediate risk and 2.50% of low risk patients according to 2008 ESC model, whereas these occurred in 1.80% of high risk and 1.45% of low risk patients according to sPESI, respectively. Predictive performance for fatal or major bleeding between two models was not significantly different (AUC sPESI 0.658, 95% CI: 0.606-0.707 versus ESC 0.512, 95% CI: 0.459-0.565, difference between AUCs 0.145, p=0.34). In hemodynamically stable patients, the combined endpoint in-hospital PE-related mortality and/or fatal or major bleeding (adverse events) occurred in 0% of patients with low risk ESC model and sPESI score 0, whilst it occurred in 5.5% of patients with low-risk ESC model but sPESI ≥1. In intermediate risk patients according to ESC model, adverse events occurred in 3.6% of patients with sPESI score 0 and 6.65% of patients with sPESI score ≥1.Conclusions: In real world, predictive performance of sPESI and the hemodynamic/biomarkers-based ESC model as prognosticator of in-hospital mortality and bleedings is similar. Combination of sPESI 0 with low risk ESC model may identify patients with very low risk of adverse events and candidate for early hospital discharge or home treatment.