Impact of an improved shortwave radiation scheme in the MAECHAM5 General Circulation Model

International audienceIn order to improve the representation of ozone absorption in the stratosphere of the MAECHAM5 general circulation model, the spectral resolution of the shortwave radiation parameterization used in the model has been increased from 4 to 6 bands. Two 20-years simulations with the general circulation model have been performed, one with the standard and the other with the newly introduced parameterization respectively, to evaluate the temperature and dynamical changes arising from the two different representations of the shortwave radiative transfer. In the simulation with the increased spectral resolution in the radiation parameterization, a significant warming of almost the entire model domain is reported. At the summer stratopause the temperature increase is about 6 K and alleviates the cold bias present in the model when the standard radiation scheme is used. These general circulation model results are consistent both with previous validation of the radiation scheme and with the offline clear-sky comparison performed in the current work with a discrete ordinate 4 stream scattering line by line radiative transfer model. The offline validation shows a substantial reduction of the daily averaged shortwave heating rate bias (1?2 K/day cooling) that occurs for the standard radiation parameterization in the upper stratosphere, present under a range of atmospheric conditions. Therefore, the 6 band shortwave radiation parameterization is considered to be better suited for the representation of the ozone absorption in the stratosphere than the 4 band parameterization. Concerning the dynamical response in the general circulation model, it is found that the reported warming at the summer stratopause induces stronger zonal mean zonal winds in the middle atmosphere. These stronger zonal mean zonal winds thereafter appear to produce a dynamical feedback that results in a dynamical warming (cooling) of the polar winter (summer) mesosphere, caused by an increased downward (upward) circulation in the winter (summer) hemisphere. In addition, the comparison of the two simulations performed with the general circulation model shows that the increase in the spectral resolution of the shortwave radiation and the associated changes in the cloud optical properties result in a warming (0.5?1 K) and moistening (3%?12%) of the upper tropical troposphere. By comparing these modeled differences with previous works, it appears that the reported changes in the solar radiation scheme contribute to improve the model mean temperature also in the troposphere

The Spectral Signature of Dust Scattering and Polarization in the Near IR to Far UV. I. Optical Depth and Geometry Effects

Spectropolarimetry from the near IR to the far UV of light scattered by dust provides a valuable diagnostic of the dust composition, grain size distribution and spatial distribution. To facilitate the use of this diagnostic, we present detailed calculations of the intensity and polarization spectral signature of light scattered by optically thin and optically thick dust in various geometries. The polarized light radiative transfer calculations are carried out using the adding-doubling method for a plane-parallel slab, and are extended to an optically thick sphere by integrating over its surface. The calculations are for the Mathis, Rumple & Nordsieck Galactic dust model, and cover the range from 1 $\mu m$ to 500 \AA. We find that the wavelength dependence of the scattered light intensity provides a sensitive probe of the optical depth of the scattering medium, while the polarization wavelength dependence provides a probe of the grain scattering properties, which is practically independent of optical depth. We provide a detailed set of predictions, including polarization maps, which can be used to probe the properties of dust through imaging spectropolarimetry in the near IR to far UV of various Galactic and extragalactic objects. In a following paper we use the codes developed here to provide predictions for the dependence of the intensity and polarization on grain size distribution and composition.Comment: 29 pages + 21 figures, accepted for the Astrophysical Journal Supplement February 2000 issue. Some revision, mostly in the introduction and the conclusions, and a couple of correction

Integrating Human-Centred Design Approach into Sustainable-Oriented 3D Printing Systems

Modern 3D printing systems have become pervasive and widely used both in professional and in informal contexts, including sustainable-oriented ones. However, the risk to create very effective but non-sustainable solutions is very high since 3D printing systems could potentially increase the environmental emergencies and the unsustainable growth. In the transition process toward sustainable ways of production and consumption, the so-called human factor still plays an important role in the achievement of sustainable-oriented actions; it drives the adoption of proper lifestyles that directly and indirectly influence the ways through which such technologies are used. Therefore, future Sustainable 3D Printing Systems should integrate the humans in the systems’ development. This study presents two important results: (a) it presents a set of interdisciplinary ‘Sustainable 3D Printing Systems’, which compose a promising sustainable-oriented scenario useful to support the transition processes toward sustainable designs and productions, and (b) it proposes a new strategy for the integration of human-centred aspects into Sustainable 3D Printing Systems, by combining insights from human-centred design approach

Colorectal cancer-screening program improves both short- and long-term outcomes: a single-center experience in Trieste

Screening programs (SC) have been proven to reduce both incidence and mortality of CRC. We retrospectively analyzed patients who underwent surgical treatment for CRC between 01/2011 and 01/2017. The current screening program in our region collects patients aged from 50 to 69. For this reason, out of a total of 600 patients, we compared 125 patients with CRC founded during the SC to 162 patients who presented with symptoms and were diagnosed between\ua050\u201369\ua0years old (NO-SC). 45% patients in the SC group were diagnosed as AJCC stage I vs 27% patients in the NO-SC group; 14% vs 20% were stage II, 14% vs 26% were stage III, and 3% vs 14% were stage IV (p 0.002). We found a significant difference in surgical approach: 89% SC vs 56% NO-SC patients had laparoscopic surgery (p 0.002). In the NO-SC group, 16% patients underwent resection in an emergency setting. Only 5% patients in the SC group had postoperative complications vs 14% patients in the NO-SC group (p 0.03). We had a 2-year OS of 86%, being 95% in the SC group and 80% in the NO-SC group (p 0.002). Likewise, the whole 2-year DFS was 77%, whereas it was 90% in the SC group and 66% in the NO-SC group (p 0.002). Screening significantly improves early diagnosis and accelerated surgical treatment. We obtained earlier stages at diagnosis, a less invasive surgical approach, and lower rates of complications and emergency surgery, all this leading to an improvement in both OS and DFS

Patients over 65 years with Acute Complicated Calculous Biliary Disease are Treated Differently - Results and Insights from the ESTES Snapshot Audit

Background: Accrued comorbidities are perceived to increase operative risk. Surgeons may offer operative treatments less often to their older patients with acute complicated calculous biliary disease (ACCBD). We set out to capture ACCBD incidence in older patients across Europe and the currently used treatment algorithms. Methods: The European Society of Trauma and Emergency Surgery (ESTES) undertook a snapshot audit of patients undergoing emergency hospital admission for ACCBD between October 1 and 31 2018, comparing patients under and C 65 years. Mortality, postoperative complications, time to operative intervention, post-acute disposition, and length of hospital stay (LOS) were compared between groups. Within the C 65 cohort, comorbidity burden,mortality, LOS, and disposition outcomes were further compared between patients undergoing operative and non-operative management. Results: The median age of the 338 admitted patients was 67 years; 185 patients (54.7%) of these were the age of 65 or over. Significantly fewer patients C 65 underwent surgical treatment (37.8% vs. 64.7%, p\0.001). Surgical complications were more frequent in the C 65 cohort than younger patients, and the mean postoperative LOS was significantly longer. Postoperative mortality was seen in 2.2% of patients C 65 (vs. 0.7%, p = 0.253). However, operated elderly patients did not differ from non-operated in terms of comorbidity burden, mortality, LOS, or postdischarge rehabilitation need. Conclusions: Few elderly patients receive surgical treatment for ACCBD. Expectedly, postoperative morbidity, LOS, and the requirement for post-discharge rehabilitation are higher in the elderly than younger patients but do not differ from elderly patients managed non-operatively. With multidisciplinary perioperative optimization, elderly patients may be safely offered optimal treatment. Trial Registration ClinicalTrials.gov (Trial # NCT03610308)

Prevalence and follow-up of occult HCV infection in an Italian population free of clinically detectable infectious liver disease.

BACKGROUND: Occult hepatitis C virus infection (OCI) is a recently described phenomenon characterized by undetectable levels of HCV-RNA in serum/plasma by current laboratory assays, with identifiable levels in peripheral blood mononuclear cells (PBMCs) and/or liver tissue by molecular tests with enhanced sensitivity. Previous results from our group showed an OCI prevalence of 3.3% in a population unselected for hepatic disease. The present study aimed to evaluate OCI prevalence in a larger cohort of infectious liver disease-free (ILDF) subjects. Clinical follow-up of OCI subjects was performed to investigate the natural history of the infection. METHODS AND FINDINGS: 439 subjects referred to a Turin Blood Bank for phlebotomy therapy were recruited. They included 314 ILDF subjects, 40 HCV-positive subjects and 85 HBV-positive subjects, of whom 7 were active HBV carriers. Six subjects (4/314 ILDF subjects [1.27%] and 2/7 active HBV carriers [28%]) were positive for HCV-RNA in PBMCs, but negative for serological and virological markers of HCV, indicating OCI. HCV genotypes were determined in the PBMCs of 3/6 OCI subjects two had type 1b; the other had type 2a/2c. OCI subjects were followed up for at least 2 years. After 12 months only one OCI persisted, showing a low HCV viral load (3.73×10(1) UI/ml). By the end of follow-up all OCI subjects were negative for HCV. No seroconversion, alteration of liver enzyme levels, or reduction of liver synthesis occurred during follow-up. CONCLUSIONS: This study demonstrated the existence of OCI in ILDF subjects, and suggested a high OCI prevalence among active HBV carriers. Follow-up suggested that OCI could be transient, with a trend toward the decrease of HCV viral load to levels undetectable by conventional methods after 12-18 months. Confirmation studies with a longer follow-up period are needed for identification of the OCI clearance or recurrence rates, and to characterize the viruses involved

A Lyman-alpha-only AGN from the Sloan Digital Sky Survey

The Sloan Digital Sky Survey has discovered a z=2.4917 radio-loud active galactic nucleus (AGN) with a luminous, variable, low-polarization UV continuum, H I two-photon emission, and a moderately broad Lyman-alpha line (FWHM = 1430 km/s) but without obvious metal-line emission. SDSS J113658.36+024220.1 does have associated metal-line absorption in three distinct, narrow systems spanning a velocity range of 2710 km/s. Despite certain spectral similarities, SDSS J1136+0242 is not a Lyman-break galaxy. Instead, the Ly-alpha and two-photon emission can be attributed to an extended, low-metallicity narrow-line region. The unpolarized continuum argues that we see SDSS J1136+0242 very close to the axis of any ionization cone present. We can conceive of two plausible explanations for why we see a strong UV continuum but no broad-line emission in this `face-on radio galaxy' model for SDSS J1136+0242: the continuum could be relativistically beamed synchrotron emission which swamps the broad-line emission; or, more likely, SDSS J1136+0242 could be similar to PG 1407+265, a quasar in which for some unknown reason the high-ionization emission lines are very broad, very weak, and highly blueshifted.Comment: AJ, in press, 10 pages emulateapj forma

Reasons and Means to Model Preferences as Incomplete

Literature involving preferences of artificial agents or human beings often assume their preferences can be represented using a complete transitive binary relation. Much has been written however on different models of preferences. We review some of the reasons that have been put forward to justify more complex modeling, and review some of the techniques that have been proposed to obtain models of such preferences

The non-convex shape of (234) Barbara, the first Barbarian

Asteroid (234) Barbara is the prototype of a category of asteroids that has been shown to be extremely rich in refractory inclusions, the oldest material ever found in the Solar System. It exhibits several peculiar features, most notably its polarimetric behavior. In recent years other objects sharing the same property (collectively known as "Barbarians") have been discovered. Interferometric observations in the mid-infrared with the ESO VLTI suggested that (234) Barbara might have a bi-lobated shape or even a large companion satellite. We use a large set of 57 optical lightcurves acquired between 1979 and 2014, together with the timings of two stellar occultations in 2009, to determine the rotation period, spin-vector coordinates, and 3-D shape of (234) Barbara, using two different shape reconstruction algorithms. By using the lightcurves combined to the results obtained from stellar occultations, we are able to show that the shape of (234) Barbara exhibits large concave areas. Possible links of the shape to the polarimetric properties and the object evolution are discussed. We also show that VLTI data can be modeled without the presence of a satellite.Comment: 10 pages, 6 figure