133 research outputs found

    Dynamical analysis and constraints for the HD 196885 system

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    The HD\,196885 system is composed of a binary star and a planet orbiting the primary. The orbit of the binary is fully constrained by astrometry, but for the planet the inclination with respect to the plane of the sky and the longitude of the node are unknown. Here we perform a full analysis of the HD\,196885 system by exploring the two free parameters of the planet and choosing different sets of angular variables. We find that the most likely configurations for the planet is either nearly coplanar orbits (prograde and retrograde), or highly inclined orbits near the Lidov-Kozai equilibrium points, i = 44^{\circ} or i = 137^{\circ} . Among coplanar orbits, the retrograde ones appear to be less chaotic, while for the orbits near the Lidov-Kozai equilibria, those around \omega= 270^{\circ} are more reliable, where \omega_k is the argument of pericenter of the planet's orbit with respect to the binary's orbit. From the observer's point of view (plane of the sky) stable areas are restricted to (I1, \Omega_1) \sim (65^{\circ}, 80^{\circ}), (65^{\circ},260^{\circ}), (115^{\circ},80^{\circ}), and (115^{\circ},260^{\circ}), where I1 is the inclination of the planet and \Omega_1 is the longitude of ascending node.Comment: 10 pages, 7 figures. A&A Accepte

    Hematopoietic Stem/Progenitor Cells Express Functional Mitochondrial Energy-Dependent Cystic Fibrosis Transmembrane Conductance Regulator

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    Bone marrow-derived hematopoietic stem/progenitor cells (HSPCs) encompass a wide array of cell subsets with different capacities of engraftment and injured tissue-regenerating potential. The characterization/isolation of the stem cell subpopulations represents a major challenge to improve the efficacy of transplantation protocols used in regenerative medicine. Cystic fibrosis (CF) is one of the diseases whose hope of cure relies on the successful application of cell-based gene therapy. This study was aimed at characterizing murine HSPCs on the basis of their bioenergetic competence and CF transmembrane conductance regulator (CFTR) expression. Positively immunoselected Sca-1(+) HSPCs encompassed 2 populations distinguished by their different size, Sca-1 expression and mitochondrial content. The smaller were the cells, the higher was Sca-1 expression and the lower was the intracellular density of functional mitochondria. Reverse transcription-polymerase chain reaction and western blotting revealed that HSPCs expressed CFTR mRNA and protein, which was also functional, as assessed by spectrofluorimetric and patch-clamp techniques. Inhibition of mitochondrial oxidative phosphorylation by oligomycin resulted in a 70% decrease of both the intracelluar adenosine triphosphate content and CFTR-mediated channel activity. Finally, HSPCs with lower Sca-1 expression and higher mitochondrial content displayed higher CFTR levels. Our findings identify 2 subpopulations in HSPCs and unveil a so-far unappreciated relationship between bioenergetic metabolism and CFTR in HSPC biology

    Proxy evidence for state-dependence of climate sensitivity in the Eocene greenhouse

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    Despite recent advances, the link between the evolution of atmospheric CO2 and climate during the Eocene greenhouse remains uncertain. In particular, modelling studies suggest that in order to achieve the global warmth that characterised the early Eocene, warmer climates must be more sensitive to CO2 forcing than colder climates. Here, we test this assertion in the geological record by combining a new high-resolution boron isotope-based CO2 record with novel estimates of Global Mean Temperature. We find that Equilibrium Climate Sensitivity (ECS) was indeed higher during the warmest intervals of the Eocene, agreeing well with recent model simulations, and declined through the Eocene as global climate cooled. These observations indicate that the canonical IPCC range of ECS (1.5 to 4.5 °C per doubling) is unlikely to be appropriate for high-CO2 warm climates of the past, and the state dependency of ECS may play an increasingly important role in determining the state of future climate as the Earth continues to warm

    Tectonic Reconstructions of the Southernmost Andes and the Scotia Sea During the Opening of the Drake Passage

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    Study of the tectonic development of the Scotia Sea region started with basic lithological and structural studies of outcrop geology in Tierra del Fuego and the Antarctic Peninsula. To nineteenth- and early twentieth-century geologists, the results of these studies suggested the presence of a submerged orocline running around the margins of the Scotia Sea. Subsequent increases in detailed knowledge about the fragmentary outcrop geology from islands distributed around the margins of the Scotia Sea, and later their interpretation in the light of the plate tectonic paradigm led to large modifications in the hypothesis such that by the present day the concept of oroclinal bending in the region persists only in vestigial form. Of the early comparative lithostratigraphic work in the region, only the likenesses between Jurassic–Cretaceous basin floor and fill sequences in South Georgia and Tierra del Fuego are regarded as strong enough to be useful in plate kinematic reconstruction by permitting the interpretation of those regions’ contiguity in mid-Mesozoic times. Marine and satellite geophysical data sets reveal features of the remaining, submerged, 98 % of the Scotia Sea region between the outcrops. These data enable a more detailed and quantitative approach to the region’s plate kinematics. In contrast to long-used interpretations of the outcrop geology, these data do not prescribe the proximity of South Georgia to Tierra del Fuego in any past period. It is, however, possible to reinterpret the geology of those two regions in terms of the plate kinematic history that the seafloor has preserved

    Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

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    Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

    Contrasting styles of (U)HP rock exhumation along the Cenozoic Adria-Europe plate boundary (Western Alps, Calabria, Corsica)

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    Since the first discovery of ultrahigh pressure (UHP) rocks 30 years ago in the Western Alps, the mechanisms for exhumation of (U)HP terranes worldwide are still debated. In the western Mediterranean, the presently accepted model of synconvergent exhumation (e.g., the channel-flow model) is in conflict with parts of the geologic record. We synthesize regional geologic data and present alternative exhumation mechanisms that consider the role of divergence within subduction zones. These mechanisms, i.e., (i) the motion of the upper plate away from the trench and (ii) the rollback of the lower plate, are discussed in detail with particular reference to the Cenozoic Adria-Europe plate boundary, and along three different transects (Western Alps, Calabria-Sardinia, and Corsica-Northern Apennines). In the Western Alps, (U)HP rocks were exhumed from the greatest depth at the rear of the accretionary wedge during motion of the upper plate away from the trench. Exhumation was extremely fast, and associated with very low geothermal gradients. In Calabria, HP rocks were exhumed from shallower depths and at lower rates during rollback of the Adriatic plate, with repeated exhumation pulses progressively younging toward the foreland. Both mechanisms were active to create boundary divergence along the Corsica-Northern Apennines transect, where European southeastward subduction was progressively replaced along strike by Adriatic northwestward subduction. The tectonic scenario depicted for the Western Alps trench during Eocene exhumation of (U)HP rocks correlates well with present-day eastern Papua New Guinea, which is presented as a modern analog of the Paleogene Adria-Europe plate boundary

    Evidence-Based PET for Abdominal and Pelvic Tumours

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    Evidence-based data about the usefulness of positron emission tomography (PET) and hybrid imaging methods (PET/CT and PET/MRI) in abdominal and pelvic tumours have been collected and discussed in this chapter. These data were divided in three sections: (1) gastrointestinal tumours, (2) uro-genital tumours, (3) gynaecological tumours. Several pooled data (diagnostic and prognostic data), clinical settings (e.g. staging, restaging, treatment evaluation) and radiotracers as fluorine-18 fluorodeoxyglucose (18F-FDG), radiolabelled choline and prostate-specific membrane antigen (PSMA) were considered

    Fast low thrust trajectories for the exploration of the outer solar system

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    Low thrust missions to destinations in the outer solar system are quite common since several years. In the majority of cases they are based on solar electric ion propulsion. Owing to the low available power, they are mostly long duration missions, in which the travel time is of the order of many years, sometimes decades, even if extensive use of gravity assist maneuvers is made.. The aim of the present paper is that of investigating which are the technological requirements to decrease drastically the travel time for low thrust missions to the outer solar system, in view not only of robotic exploration but also of future human exploration of the satellites of the giant planets. In the latter case low thrust spacecraft may be used at least as cargo ship to prepare the human presence in such distant places

    High-Viscosity HPMC as a Film-Coating Agent

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    The possibility of using high viscosity grades of hydroxypropylmethylcellulose (HPMC) as a film forming agent in a conventional coating process has been investigated. Ethanol/water mixtures having different weight ratios (5 to 18) and containing up to 5 % of HPMC revealed to be suitable. The influence of some formulation additives (talc, PVP and plasticizers) on both the overall coating process and the in-vitro release profiles of ketoprofen containing coated tablets was also investigated and discussed
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