Rotationally resolved spectroscopy of (20000) Varuna in the near-infrared

Models of the escape and retention of volatiles by minor icy objects exclude any presence of volatile ices on the surface of TNOs smaller than ~1000km in diameter at the typical temperature in this region of the solar system, whereas the same models show that water ice is stable on the surface of objects over a wide range of diameters. Collisions and cometary activity have been used to explain the process of surface refreshing of TNOs and Centaurs. These processes can produce surface heterogeneity that can be studied by collecting information at different rotational phases. The aims of this work are to study the surface composition of (20000)Varuna, a TNO with a diameter ~650km and to search for indications of rotational variability. We observed Varuna during two consecutive nights in January 2011 with NICS@TNG obtaining a set of spectra covering the whole rotation period of Varuna. After studying the spectra corresponding to different rotational phases, we did not find any indication of surface variability. In all the spectra, we detect an absorption at 2{\mu}m, suggesting the presence of water ice on the surface. We do not detect any other volatiles on the surface, although the S/N is not high enough to discard their presence. Based on scattering models, we present two possible compositions compatible with our set of data and discuss their implications in the frame of the collisional history of the Kuiper Belt. We find that the most probable composition for the surface of Varuna is a mixture of amorphous silicates, complex organics, and water ice. This composition is compatible with all the materials being primordial. However, our data can also be fitted by models containing up to a 10% of methane ice. For an object with the characteristics of Varuna, this volatile could not be primordial, so an event, such as an energetic impact, would be needed to explain its presence on the surface.Comment: 6 pages, 5 figures, to be published in A&

Advancing Economic Research on the Free and Open Source Software Mode of Production

Early contributions to the academic literature on free/libre and open source software (F/LOSS) movements have been directed primarily at identifying the motivations that account for the sustained and often intensive involvement of many people in this non-contractual and unremunerated productive activity. This issue has been particularly prominent in economists’ contributions to the literature, and it reflects a view that widespread voluntary participation in the creation of economically valuable goods that is to be distributed without charge constitutes a significant behavioral anomaly. Undoubtedly, the motivations of F/LOSS developers deserve to be studied more intensively, but not because their behaviors are unique, or historically unprecedented. In this essay we argue that other aspects of the “open source” phenomenon are just as intriguing, if not more so, and possibly are also more consequential topics for economic analysis. We describe the re-focusing and re-direction of empirical and theoretical research in an integrated international project (based at Stanford University/SIEPR) that aims at better understanding a set of less widely discussed topics: the modes of organization, governance and performance of F/LOSS development -- viewed as a collective distributed mode of production.. We discuss of the significance of tackling those questions in order to assess the potentialities of the “open source way of working” as a paradigm for a broader class of knowledge and information- goods production, and conclude with proposals for the trajectory of future research along that line.

The illness trajectory in Marilyn Monroe‘s psychological autopsy: from autism spectrum disorder to borderline personality disorder and bipolar disorder with catatonia

Objective: A mounting body of literature is showing that, in the clinical and general population, autism spectrum disorder (ASD) or autistic traits (ATs) would appear to be spread along a continuum, reaching the highest levels among individuals affected by other mental disorders, such as borderline personality disorder (BPD) and bipolar disorder (BD). Furthermore, individuals with ASD or ATs appear to be more vulnerable to psychological traumas, with greater likelihood of developing post-traumatic stress disorder (PTSD) and BD. Marilyn Monroe was a famous actress, singer and model, as well as one of the most admired stars of American cinema and a timeless icon. The present report debates the possibility to explore Marilyn Monroe’s case under a neurodevelopmental perspective according to which a ASD favored, on one hand, her worldwide success and, on the other, her mental illness trajectory. Method: The analysis is based on the review of her four biographies written by psychiatrists and clinical psychologists, her complete filmography, interviews, filmed material and personal scripts. Results: The present work reconstructed a hypothetical illness trajectory originating from a ASD and culminating in a BD with unspecified catatonia, followed by premature death whose cause has never been clarified. The description of this illness trajectory also confirms the strong impact of psychological traumas on the substrate of ASD vulnerability and its correlation with the development of BPD and BD. Conclusions: This paper suggests Marilyn Monroe as a possible prototypical case of BPD under a neurodevelopmental perspective that accounts the ASD, as reported in DSM-5-TR (2022), in verbal adult without intellectual impairment, high-functioning autism (HFA), as vulnerability background predisposing to the progression to BPD and BD with unspecified catatonia, triggered by multiple traumas

On the correlation between fragility and stretching in glassforming liquids

We study the pressure and temperature dependences of the dielectric relaxation of two molecular glassforming liquids, dibutyl phtalate and m-toluidine. We focus on two characteristics of the slowing down of relaxation, the fragility associated with the temperature dependence and the stretching characterizing the relaxation function. We combine our data with data from the literature to revisit the proposed correlation between these two quantities. We do this in light of constraints that we suggest to put on the search for empirical correlations among properties of glassformers. In particular, argue that a meaningful correlation is to be looked for between stretching and isochoric fragility, as both seem to be constant under isochronic conditions and thereby reflect the intrinsic effect of temperature

Uncertainty Propagation in Integrated Airframe Propulsion System Analysis for Hypersonic Vehicles

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90676/1/AIAA-2011-2394-420.pd

Surface Composition of Pluto's Kiladze Area and Relationship to Cryovolcanism

A link between exposures of water (H${}_{2}$O) ice with traces of an ammoniated compound (e.g., a salt) and the probable effusion of a water-rich cryolava onto the surface of Pluto has been established in previous investigations (Dalle Ore et al. 2019). Here we present the results from the application of a machine learning technique and a radiative transfer model to a water-ice-rich exposure in Kiladze area and surroundings on Pluto. We demonstrate the presence of an ammoniated material suggestive of an undetermined but relatively recent emplacement event. Kiladze lies in a region of Pluto's surface that is structurally distinct from that of the areas where similar evidence points to cryovolcanic activity at some undetermined time in the planet's history. Although the Kiladze depression superficially resembles an impact crater, a close inspection of higher-resolution images indicates that the feature lacks the typical morphology of a crater. Here we suggest that a cryolava water carrying an ammoniated component may have come onto the surface at the Kiladze area via one or more volcanic collapses, as in a resurgent volcanic caldera complex. Large regions east of Kiladze also exhibit the presence of H${}_{2}$O ice and have graben-like structures suggestive of cryovolcanic activity, but with existing data are not amenable to the detailed search that might reveal an ammoniated component.Comment: 28 pages, 11 figures, submitted to Icaru

The consequence of excess configurational entropy on fragility: the case of a polymer/oligomer blend

By taking advantage of the molecular weight dependence of the glass transition of polymers and their ability to form perfectly miscible blends, we propose a way to modify the fragility of a system, from fragile to strong, keeping the same glass properties, i.e. vibrational density of states, mean-square displacement and local structure. Both slow and fast dynamics are investigated by calorimetry and neutron scattering in an athermal polystyrene/oligomer blend, and compared to those of a pure 17-mer polystyrene considered to be a reference, of same Tg. Whereas the blend and the pure 17-mer have the same heat capacity in the glass and in the liquid, their fragilities differ strongly. This difference in fragility is related to an extra configurational entropy created by the mixing process and acting at a scale much larger than the interchain distance, without affecting the fast dynamics and the structure of the glass

NetStep: a micro-stepped distributed network simulation framework

short paper.International audienceThis paper presents NetStep, a prototype for the distributed simulation of very large scale network simulations, such as the simulation of peer-to-peer applications. We use simulation micro-steps as a means for optimizing the overlap of communications and computations, without changing the original event-driven model. As a consequence, NetStep allows for the reuse of unmodified existing sequential simulators for building large-scale distributed simulations: the overall simulation is divided both in time and space, into a large number of simulation micro-steps, each of which being executed by a legacy sequential simulator. By choosing the time-step smaller than the minimal look-ahead due to communications, we avoid the need for synchronization between Logical Processes during the simulation. Instead, the simulated communications become inputs and outputs of the simulation micro-steps, and are routed in parallel between LPs by a NetStep dedicated entity. Our prototype is based on the SimGrid sequential simulator

Effect of rearing system on body traits and fillet quality of meagre (Argyrosomus regius, Asso 1801) chilled for a short time

The purpose of this study was to evaluate qualitative traits of meagre (Argyrosomus regius) from two different rearing systems (land-based tank filled with geothermal water vs offshore sea cage) and after short-term storage at chilling temperature (1, 2, or 3 days). Fish originated from the same batch were fed the same diet. Morpho-biometric traits, L*, a*, and b* colour parameters, texture, free water, proximate composition, total lipids, fatty acids, iron, and selenium contents were analyzed in the fillets. Most parameters were affected by rearing system. Compared to tank-reared fish, caged fish were shorter, poorer in visceral fat, and had higher incidence in cavity content and liver, lower incidence in gonads and head. Caged fish also had softer fillets in the epaxial site, which showed a higher tendency towards greenish colour. Caged fish also showed higher lipid content but lower Fe and Se content. Tank-reared fish fillets were more abundant in PUFAn-3, mainly due to DHA (18.54 vs 12.95%; P<0.001) and consequently showed the best healthiness indexes. Minimal changes, mostly involving colour and texture, were detected during the first three days of refrigerated storage. During storage, no significant modification of the parameters investigated could be ascribed to the rearing system