The importance of time of day for magnetic body alignment in songbirds.

Spontaneous magnetic alignment is the simplest known directional response to the geomagnetic field that animals perform. Magnetic alignment is not a goal directed response and its relevance in the context of orientation and navigation has received little attention. Migratory songbirds, long-standing model organisms for studying magnetosensation, have recently been reported to align their body with the geomagnetic field. To explore whether the magnetic alignment behaviour in songbirds is involved in the underlying mechanism for compass calibration, which have been suggested to occur near to sunset, we studied juvenile Eurasian reed warblers (Acrocephalus scirpaceus) captured at stopover during their first autumn migration. We kept one group of birds in local daylight conditions and an experimental group under a 2 h delayed sunset. We used an ad hoc machine learning algorithm to track the birds' body alignment over a 2-week period. Our results show that magnetic body alignment occurs prior to sunset, but shifts to a more northeast-southwest alignment afterwards. Our findings support the hypothesis that body alignment could be associated with how directional celestial and magnetic cues are integrated in the compass of migratory birds.

Electrochromic evaluation of airbrushed water-dispersible W18O49nanorods obtained by microwave-assisted synthesis.

Motivated by the technological relevance of tungsten oxide nanostructures as valuable materials for energy saving technology, electrochemical and electrochromic characteristics of greener processed nanostructured W18O49-based electrodes are discussed in this work. For the purpose, microwave-assisted water-dispersible W18O49nanorods have been synthesized and processed into nanostructured electrodes. An airbrushing technique has been adopted as a cost-effective large-area scalable methodology to deposit the W18O49nanorods onto conductive glass. This approach preserves the morphological and crystallographic habit of native nanorods and allows highly homogeneous transparent coating where good electronic coupling between nanowires is ensured by a mild thermal treatment (250 °C, 30 min). Morphological and structural characteristics of active material were investigated from the synthesis to the nanocrystal deposition process by transmission and scanning electron microscopy, x-ray diffraction, atomic force microscopy and Raman spectroscopy. The as-obtained nanostructured film exhibited good reversible electrochemical features through several intercalation-deintercalation cycles. The electrochromic properties were evaluated on the basis of spectro-electrochemical measurements and showed significant optical contrast in the near-infrared region and high coloration efficiency at 550 nm.

Should we operate on all patients with COVID-19 and proximal femoral fractures? An analysis of thirty, sixty, and ninety day mortality rates based on patients' clinical presentation and comorbidity: a multicentric study in Northern Italy.

PURPOSE: This study aims to evaluate 30-60-90-day mortality of operated proximal femur fractures (PFFs) suffering from COVID-19 and correlation with patients' clinical presentation and comorbidities. METHODS: Between February 1, 2020, and December 31, 2020, patients with COVID-19 infection and surgically treated PFF were included. Patients' demographic characteristics, oxygen (O2) therapy, comorbidities, and AO type fracture were collected. Chi-square test or Fisher test and hazard ratio were used to assessing the correlation between mortality rate, patient characteristics, and COVID-19 status. Kaplan-Meyer curve was used to analyze 30-60-90-day mortality. Level of significance was set as p < 0.05. RESULTS: Fifty-six patients (mean age of 82.7 ± 8.85 years) were included. Thirty-day mortality rate was 5%, which increased to 21% at 60 days and 90 days. Eleven patients died, eight due to AO type A-like and three due to AO type B-like fractures. No significant difference in mortality rate between patients with cardiopulmonary comorbidity or no cardiopulmonary comorbidity was found (p = 0.67); a significant difference in patients with chronic obstructive pulmonary disease (COPD) or history of pulmonary embolism (PE) and patients without COPD was found (p = 0.0021). A significant difference between asymptomatic/mild symptomatic COVID-19 status and symptomatic COVID-19 status was found (p = 0.0415); a significant difference was found for O2 therapy with < 4 L/min and O2 therapy ≥ 4 L/min (p = 0.0049). CONCLUSION: Thirty-day mortality rate of COVID-19 infection and PFFs does not differ from mortality rate of non-COVID-19 PFFs. However, patients with pre-existing comorbidities and symptomatic COVID-19 infection requiring a high volume of O2 therapy have a higher incidence of 60-90-day mortality when surgically treated.

Transplantation during the COVID-19 pandemic: nothing noble is accomplished without danger.

The global health crisis due to the fast spread of coronavirus disease (COVID-19) has caused major disruption in all aspects of healthcare. Transplantation is one of the most affected sectors, as it relies on a variety of services that have been drastically occupied to treat patients affected by COVID-19. With this report from two transplant centers in Italy, we aim to reflect on resource organization, organ allocation, virus testing and transplant service provision during the course of the pandemic and to provide actionable information highlighting advantages and drawbacks.To what extent can we preserve the noble purpose of transplantation in times of increased danger? Strategies to minimize risk exposure to the transplant population and health- workers include systematic virus screening, protection devices, social distancing and reduction of patients visits to the transplant center. While resources for the transplant activity are inevitably reduced, new dilemmas arise to the transplant community: further optimization of time constraints during organ retrievals and implantation, less organs and blood products donated, limited space in the intensive care unit and the duty to maintain safety and outcomes.

SARS-CoV2 and immunosuppression: A double-edged sword.

Severe acute respiratory syndrome Coronavirus 2 (SARS-Cov2) outbreak has caused a pandemic rapidly impacting on the way of life of the entire world. This impact in the specific setting of transplantation and immunosuppression has been poorly explored to date. Discordant data exist on the impact of previous coronavirus outbreaks on immunosuppressed patients. Overall, only a very limited number of cases have been reported in literature, suggesting that transplanted patients not necessarily present an increased risk of severe SARS-Cov2-related disease compared to the general population. We conducted a literature review related to the impact of immunosuppression on coronavirus infections including case reports and series describing immunosuppression management in transplant recipients. The role of steroids, calcineurin inhibitors, and mycophenolic acid has been explored more in detail. A point-in-time snapshot of the yet released literature and some considerations in relation to the use of immunosuppression in SARS-Cov2 infected transplant recipients are provided here for the physicians dealing with immunocompromised patients.

Magnetic body alignment in migratory songbirds: a computer vision approach.

Several invertebrate and vertebrate species have been shown to align their body relative to the geomagnetic field. Many hypotheses have been proposed to explain the adaptive significance of magnetic body alignment outside the context of navigation. However, experimental evidence to investigate alternative hypotheses is still limited. We present a new setup to track the preferential body alignment relative to the geomagnetic field in captive animals using computer vision. We tested our method on three species of migratory songbirds and provide evidence that they align their body with the geomagnetic field. We suggest that this behaviour is involved in the underlying mechanism for compass orientation and calibration, which may occur near to sunrise and sunset periods. Our method could easily be extended to other species and used to test a large set of hypotheses to explain the mechanisms behind the magnetic body alignment and the magnetic sense in general.

Magnetic storms disrupt nocturnal migratory activity in songbirds.

Birds possess a magnetic sense and rely on the Earth's magnetic field for orientation during migration. However, the geomagnetic field can be altered by solar activity at relative unpredictable intervals. How birds cope with the temporal geomagnetic variations caused by solar storms during migration is still unclear. We addressed this question by reproducing the effect of a solar storm on the geomagnetic field and monitoring the activity of three songbird species during autumn migration. We found that only the European robin reduced nocturnal migratory restlessness in response to simulated solar storms. At the same time, robins increased activity during early morning. We suggest that robins reduced activity at night when the perception of magnetic information would be strongly disrupted by temporal variations of the magnetic field, to extend their migration during daytime when several visual cues become available for orientation. The other two species, chiffchaff and dunnock, showing low or no nocturnal migratory activity, did not respond to the solar storm by changing activity.

Tailoring water stability of cellulose nanopaper by surface functionalization.

Cellulose nanopaper (CNP) features appealing properties, including transparency, flatness, a low thermal expansion coefficient and thermal stability, often outperforming conventional paper. However, free-standing crystalline cellulose films usually swell in water or upon moisture sorption, compromising part of their outstanding properties. This remains a major problem whenever working in a water environment is required. Freestanding cellulose nanopaper is prepared by solution casting water suspensions of cellulose nanocrystals with an average width of 10 nm and an average aspect ratio of 28, isolated from Avicel by acid hydrolysis and extensively characterized by AFM and FE-SEM measurements and GPC detection of their degree of polymerization. We demonstrate by elemental analyses, FT-IR, Raman spectroscopy, XRD measurements and water contact angle detection that wet treatment with lauroyl chloride results in surface hydrophobization of nanopaper. The hydrophobized nanopaper, C12-CNP, shows a more compact surface morphology than the starting CNP, due to the effect of chemical functionalization, and presents enhanced resistance to water, as assessed by electrochemical permeation experiments. The new hydrophobized nanopaper is a promising substrate for thin film devices designed to work in a humid environment.

Distinctive diffusive properties of swimming planktonic copepods in different environmental conditions.

Suspensions of small planktonic copepods represent a special category in the realm of active matter, as their size falls within the range of colloids, while their motion is so complex that it cannot be rationalized according to basic models of self-propelled particles. Indeed, the wide range of individual variability and swimming patterns resemble the behaviour of much larger animals. By analysing hundreds of three-dimensional trajectories of the planktonic copepod Clausocalanus furcatus, we investigate the possibility of detecting how the motion of this species is affected by different external conditions, such as the presence of food and the effect of gravity. While this goal is hardly achievable by direct inspection of single organism trajectories, we show that this is possible by focussing on simple average metrics commonly used to characterize colloidal suspensions, such as the mean square displacement and the dynamic correlation functions. We find that the presence of food leads to the onset of a clear localization that separates a short-time ballistic from a long-time diffusive regime. Such a benchmark reflects the tendency of C. furcatus to remain temporally feeding in a limited space and disappears when food is absent. Localization is clearly evident in the horizontal plane, but is negligible in the vertical direction, due to the effect of gravity. Our results suggest that simple average descriptors may provide concise and useful information on the swimming properties of planktonic copepods, even though single organism behaviour is strongly heterogeneous.

Exploring the boundaries of quantum mechanics: advances in satellite quantum communications.

Recent interest in quantum communications has stimulated great technological progress in satellite quantum technologies. These advances have rendered the aforesaid technologies mature enough to support the realization of experiments that test the foundations of quantum theory at unprecedented scales and in the unexplored space environment. Such experiments, in fact, could explore the boundaries of quantum theory and may provide new insights to investigate phenomena where gravity affects quantum objects. Here, we review recent results in satellite quantum communications and discuss possible phenomena that could be observable with current technologies. Furthermore, stressing the fact that space represents an incredible resource to realize new experiments aimed at highlighting some physical effects, we challenge the community to propose new experiments that unveil the interplay between quantum mechanics and gravity that could be realizable in the near future.This article is part of a discussion meeting issue 'Foundations of quantum mechanics and their impact on contemporary society'.

A New Precision Spectroscopy Based Method for Boltzmann Constant Determination and Primary Thermometry.

We propose a new independent thermometry method, line strength ratio thermometry (LRT), based on optical spectroscopy measurement of the line strength intensity ratio R between pairs of molecular transitions. Due to strong dependence of R on kT, a given measurement uncertainty δR for R reflects in a small uncertainty of kT determination. By assuming experimental uncertainties of R and T to be those reported in literature, we foresee a k determination at the 5 ppm level, which is better than the most precise k determination by using Doppler broadening thermometry (DBT). In the frame of a new definition of the SI Kelvin unit, based on k as fixed constant, once the k constant is exactly established, LRT is proposed as a high resolution noncontact thermometry technique for absolute temperature measurements of gas samples at the ppm level.

Route simulations, compass mechanisms and long-distance migration flights in birds.

Bird migration has fascinated humans for centuries and routes crossing the globe are now starting to be revealed by advanced tracking technology. A central question is what compass mechanism, celestial or geomagnetic, is activated during these long flights. Different approaches based on the geometry of flight routes across the globe and route simulations based on predictions from compass mechanisms with or without including the effect of winds have been used to try to answer this question with varying results. A major focus has been use of orthodromic (great circle) and loxodromic (rhumbline) routes using celestial information, while geomagnetic information has been proposed for both a magnetic loxodromic route and a magnetoclinic route. Here, we review previous results and evaluate if one or several alternative compass mechanisms can explain migration routes in birds. We found that most cases could be explained by magnetoclinic routes (up to 73% of the cases), while the sun compas s could explain only 50%. Both magnetic and geographic loxodromes could explain <25% of the routes. The magnetoclinic route functioned across latitudes (1°S-74°N), while the sun compass only worked in the high Arctic (61-69°N). We discuss the results with respect to orientation challenges and availability of orientation cues.

Instantaneous threat escape and differentiated refuge demand among zooplankton taxa.

Most animals, including aquatic crustacean zooplankton, perform strong avoidance movements when exposed to a threat, such as ultraviolet radiation (UVR). We here show that the genera Daphnia and Bosmina instantly adjust their vertical position in the water in accordance with the present UVR threat, i.e., seek refuge in deeper waters, whereas other taxa show less response to the threat. Moreover, Daphnia repeatedly respond to UVR pulses, suggesting that they spend more energy on movement than more stationary taxa, for example, during days with fluctuating cloud cover, illustrating nonlethal effects in avoiding UVR threat. Accordingly, we also show that the taxa with the most contrasting behavioral responses differ considerably in photoprotection, suggesting different morphological and behavioral strategies in handling the UVR threat. In a broader context, our studies on individual and taxa specific responses to UVR provide insights into observed spatial and temporal distribution in natural ecosystems.

Interference at the Single Photon Level Along Satellite-Ground Channels.

Quantum interference arising from the superposition of states is striking evidence of the validity of quantum mechanics, confirmed in many experiments and also exploited in applications. However, as for any scientific theory, quantum mechanics is valid within the limits in which it has been experimentally verified. In order to extend such limits, it is necessary to observe quantum interference in unexplored conditions such as moving terminals at large distances in space. Here, we experimentally demonstrate single photon interference at a ground station due to the coherent superposition of two temporal modes reflected by a rapidly moving satellite a thousand kilometers away. The relative speed of the satellite induces a varying modulation in the interference pattern. The measurement of the satellite distance in real time by laser ranging allows us to precisely predict the instantaneous value of the interference phase. We then observed the interference patterns with a visibility up to 67% with three different satellites and with a path length up to 5000 km. Our results attest to the viability of photon temporal modes for fundamental tests of physics and quantum communication in space.

Experimental Satellite Quantum Communications.

Quantum communication (QC), namely, the faithful transmission of generic quantum states, is a key ingredient of quantum information science. Here we demonstrate QC with polarization encoding from space to ground by exploiting satellite corner cube retroreflectors as quantum transmitters in orbit and the Matera Laser Ranging Observatory of the Italian Space Agency in Matera, Italy, as a quantum receiver. The quantum bit error ratio (QBER) has been kept steadily low to a level suitable for several quantum information protocols, as the violation of Bell inequalities or quantum key distribution (QKD). Indeed, by taking data from different satellites, we demonstrate an average value of QBER=4.6% for a total link duration of 85 s. The mean photon number per pulse µ_{sat} leaving the satellites was estimated to be of the order of one. In addition, we propose a fully operational satellite QKD system by exploiting our communication scheme with orbiting retroreflectors equipped with a modulator, a very compact payload. Our scheme paves the way toward the implementation of a QC worldwide network leveraging existing receivers.

Induced tolerance expressed as relaxed behavioural threat response in millimetre-sized aquatic organisms.

Natural selection shapes behaviour in all organisms, but this is difficult to study in small, millimetre-sized, organisms. With novel labelling and tracking techniques, based on nanotechnology, we here show how behaviour in zooplankton (Daphnia magna) is affected by size, morphology and previous exposure to detrimental ultraviolet radiation (UVR). All individuals responded with immediate downward swimming to UVR exposure, but when released from the threat they rapidly returned to the surface. Large individuals swam faster and generally travelled longer distances than small individuals. Interestingly, individuals previously exposed to UVR (during several generations) showed a more relaxed response to UVR and travelled shorter total distances than those that were naive to UVR, suggesting induced tolerance to the threat. In addition, animals previously exposed to UVR also had smaller eyes than the naive ones, whereas UVR-protective melanin pigmentation of the animals was similar between populations. Finally, we show that smaller individuals have lower capacity to avoid UVR which could explain patterns in natural systems of lower migration amplitudes in small individuals. The ability to change behavioural patterns in response to a threat, in this case UVR, adds to our understanding of how organisms navigate in the 'landscape of fear', and this has important implications for individual fitness and for interaction strengths in biotic interactions.

Response of recurrent BRAFV600E mutated ganglioglioma to Vemurafenib as single agent.

BACKGROUND: Ganglioglioma (GG) and pilocytic astrocytoma (PA) represent the most frequent low-grade gliomas (LGG) occurring in paediatric age. LGGs not amenable of complete resection (CR) represent a challenging subgroup where traditional treatments often fail. Activation of the MAP Kinase (MAPK) pathway caused by the BRAFV600E mutation or the KIAA1549-BRAF fusion has been reported in pediatric GG and PA, respectively. CASE PRESENTATION: We report on a case of BRAFV600E mutated cervicomedullary GG treated with standard chemotherapy and surgery. After multiple relapse, BRAF status was analyzed by immunohistochemistry and sequencing showing a BRAFV600E mutation. Treatment with Vemurafenib as single agent was started. For the first time, a radiological and clinical response was obtained after 3 months of treatment and sustained after 6 months. CONCLUSION: Our experience underline the importance of understanding the driver molecular alterations of LGG and suggests a role for Vemurafenib in the treatment of pediatric GG not amenable of complete surgical resection.