162 research outputs found

    A method to deconvolve stellar rotational velocities

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    Rotational speed is an important physical parameter of stars and knowing the distribution of stellar rotational velocities is essential for the understanding stellar evolution. However, it cannot be measured directly but the convolution of the rotational speed and the sine of the inclination angle, vsiniv \sin i. We developed a method to deconvolve this inverse problem and obtain the cumulative distribution function (CDF) for stellar rotational velocities extending the work of Chandrasekhar & M\"unch (1950). This method is applied a) to theoretical synthetic data recovering the original velocity distribution with very small error; b) to a sample of about 12.000 field main--sequence stars, corroborating that the velocity distribution function is non--Maxwellian, but is better described by distributions based on the concept of maximum entropy, such as Tsallis or Kaniadakis distribution functions. This is a very robust and novel method that deconvolve the rotational velocity cumulative distribution function from a sample of vsiniv \sin i data in just one single step without needing any convergence criteria.Comment: Accepted in A&

    Performance, Stability, and Control Investigation at Mach Numbers from 0.4 to 0.9 of a Model of the "Swallow" with Outer Wing Panels Swept 25 degree with and without Power Simulation

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    An investigation of the performance, stability, and control characteristics of a variable-sweep arrow-wing model (the "Swallow") with the outer wing panels swept 25 deg has been conducted in the Langley 16-foot transonic tunnel. The wing was uncambered and untwisted and had RAE 102 airfoil sections with a thickness-to-chord ratio of 0.14 normal to the leading edge. Four outboard engines located above and below the wing provided propulsive thrust, and, by deflecting in the pitch direction and rotating in the lateral plane, also produced control forces. A pair of swept lateral fins and a single vertical fin were mounted on each engine nacelle to provide aerodynamic stability and control. Jets-off data were obtained with flow-through nacelles, stimulating the effects of inlet flow; jet thrust and hot-jet interference effects were obtained with faired-nose nacelles housing hydrogen peroxide gas generators. Six-component force and moment data were obtained through a Mach number range of 0.40 to 0.90 at angles of attack and angles of sideslip from 0 deg to 15 deg. Longitudinal, directional, and lateral control were obtained by deflecting the nacelle-fin combinations as elevators, rudders, and ailerons at several fixed angles for each control

    Performance assessment of Posidonia oceanica (L.) Delile restoration experiment on dead matte twelve years after planting\u2014structural and functional meadow features

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    Following the restoration of natural conditions by reducing human pressures, reforestation is currently considered a possible option to accelerate the recovery of seagrass habitats. Long-term monitoring programs theoretically represent an ideal solution to assess whether a reforestation plan has produced the desired results. Here, we report on the performance of a 20 m2 patch of Posidonia oceanica transplanted on dead matte twelve years after transplantation in the Gulf of Palermo, northwestern Sicily. Photo mosaic performed in the area allowed us to detect 23 transplanted patches of both regular and irregular shape, ranging from 0.1 to 2.7 m2 and an overall surface close to 19 m2. Meadow density was 331.6 \ub1 17.7 shoot m-2 (currently five times higher than the initial value of 66 shoots m-2), and it did not show statistical differences from a close by natural meadow (331.2 \ub1 14.9). Total primary production, estimated by lepidochronology, varied from 333.0 to 332.7 g dw m2/year, at the transplanted and natural stand, respectively. These results suggest that complete restoration of P. oceanica on dead matte is possible in a relatively short time (a decade), thus representing a good starting point for upscaling the recovery of the degraded meadows in the area

    Extended latissimus dorsi kite flap (eld-k flap). Revisiting an old place for a total autologous breast reconstruction in patients with medium to large breasts

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    Background: The latissimus dorsi (LD) flap represents one of the most reliable methods for autologous breast reconstruction. However, in many patients, the exclusive use of this technique may not guarantee the restoration of an adequate volume and projection. We report our experience with the extended latissimus dorsi kite flap (ELD-K flap), an alternative surgical approach to maximize the volume of the fleur-de-lis pattern LD flap, for total autologous breast reconstruction. Methods: Between 2016 and 2018, 23 patients were subjected to mastectomy and immediate autologous reconstruction with "extended latissimus dorsi kite flap" (ELD-K flap), technique that employs an extended version of the LD musculocutaneous flap, based on the skeletonized thoracodorsal pedicle and a trilobate skin incision with an inferiorly based vertical branch. The BREAST-Q questionnaire was administered preoperatively, and one year after surgery to evaluate the quality of life results of the patients. BREAST-Q latissimus dorsi module was also provided. Results: Average body mass index was 29.7 kg/m2 (range 25–40 kg/m2). Mild complications occurred in only six cases, and eight patients underwent treatment to improve the donor site scar outcome. Patients indicated high scores in quality of life measures with an increase in all BREAST domains from the preoperative to the postoperative period. A statistically significant increase (p < 0.05) was noted in: “overall satisfaction with breasts” (p < 0.05), “psychosocial well-being” (p < 0.05), “physical impact of the surgery” (p < 0.05). Within the LD module, participants reported a mean score of, respectively, 73.8 and 67.9 for “satisfaction with back” and “satisfaction with shoulder and back function” domains. Conclusions: The extended incision allows the recruitment of additional tissue to provide enough volume to complete the reconstruction without implants. The isolation of the vascular pedicle allows for extreme freedom and mobilization of the flap, ensuring adequate filling of the breast. ELD-K flap may expand the indications for a total autologous LD immediate breast reconstruction, representing an additional and reliable alternative in selected cohorts of patients. Level of Evidence IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266

    Intellectual disability, sensation and thinking through affect

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    Acute coronary syndromes (ACSs) represent a high-risk condition, as enhanced platelet reactivity importantly influences myocardial perfusion and procedural results after percutaneous coronary intervention (PCI). In fact, higher rate of periprocedural myocardial infarction (PMI) and reduced event-free survival have been reported in these patients. The single nucleotide polymorphism Leu33Pro of platelet glycoprotein IIIa has been related to an increased platelet reactivity, a lower response to antiplatelet agents and higher risk of stent restenosis. Therefore, our aim was to evaluate the impact of this polymorphism on PMI in patients undergoing PCI for non-ST-segment elevation MI (NSTEMI). Our population is represented by 478 consecutive patients undergoing coronary angioplasty for NSTEMI. Cardiac biomarkers were monitored at intervals from 8 to 48 h after the procedure. Genetic analysis was performed to assess the presence of Leu33Pro polymorphism. A total of 156 patients (32.6%) were polymorphic. Clinical features did not differ according to genetic status, neither pharmacological treatment pre and during angioplasty. PlA carriers had lower rate of calcifications (P = 0.01) and higher coronary tortuosity (P = 0.03) at angiography and underwent more frequently to thrombectomy (P = 0.05). PCI-related complications did not differ according to genotype. Leu33Pro polymorphism was not associated with increased risk of periprocedural myonecrosis and PMI even after correction for baseline differences, [odds ratio (OR) (95% confidence interval (CI) = 0.70 (0.44-1.13), P = 0.15 for PMI and OR (95% CI) = 0.77 (0.53-1.11), P = 0.17 for myonecrosis, respectively]. Results were confirmed in high-risk subgroups of patients. In conclusion, among patients undergoing PCI for ACS, the polymorphism Leu33Pro of platelet glycoprotein IIIa is not associated with increased risk of PMI

    WebGIS implementation for dynamic mapping and visualization of coastal geospatial data: A case study of BESS project

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    Within an E.U.-funded project, BESS (Pocket Beach Management and Remote Surveillance System), the notion of a geographic information system is an indispensable tool for managing the dynamics of georeferenced data and information for any form of territorial planning. This notion was further explored with the creation of a WebGIS portal that will allow local and regional stake-holders/authorities obtain an easy remote access tool to monitor the status of pocket beaches (PB) in the Maltese Archipelago and Sicily. In this paper, we provide a methodological approach for the implementation of a WebGIS necessary for very detailed dynamic mapping and visualization of geospatial coastal data; the description of the dataset necessary for the monitoring of coastal areas, especially the PBs; and a demonstration of a case study for the PBs of Sicily and Malta by using the methodology and the dataset used during the BESS project. Detailed steps involved in the creation of the WebGIS are presented. These include data preparation, data storage, and data publication and transformation into geo-services. With the help of different Open Geospatial Consortium pro-tocols, the WebGIS displays different layers of information for 134 PBs including orthophotos, sed-imentological/geomorphological beach characteristics, shoreline evolution, geometric and morphological parameters, shallow water bathymetry, and photographs of pocket beaches. The WebGIS allows not only for identifying, evaluating, and directing potential solutions to present and arising issues, but also enables public access and involvement. It reflects a platform for future local and regional coastal zone monitoring and management, by promoting public/private involvement in addressing coastal issues and providing local public administrations with an improved technology to monitor coastal changes and help better plan suitable interventions

    Swift observations of IBL and LBL objects

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    BL Lacs are an enigmatic class of active galactic nuclei (AGNs), characterized by the non-thermal continuum typically attributed to synchrotron and inverse Compton emission. Depending on the frequency location of the maxima of these components, they are subdivided into three subclasses LBLs, IBLs, and HBLs. We present the results of a set of observations of eight BL Lac objects of LBL and IBL type performed by the XRT and UVOT detectors onboard the Swift satellite between January 2005 and November 2006. We are mainly interested in measuring the spectral parameters, and particularly the steepness between the UV and the X-ray band, useful for determining the classification of these sources. We compare the behavior of these sources with previous XMM-Newton, BeppoSAX obser- vations and with historical data in the X-ray and in the optical band. We are also interested in classifying the sources in our sample on the basis of the observations and comparing them with their classification presented in literature. We performed X-ray spectral analysis of observed BL Lac objects using a simple powerlaw and in a few cases the log-parabolic model. We also combined the UV emission with the low energy X-ray data to We used observational data to classify sources in our sample and derived parameters of their spectral energy distribution. We found that for the IBLs X-rays low states show features of the high energy component, usually interpreted as due to inverse Compton emission. Sources in our sample exhibit a range of temporal UV and X-ray behaviors, some objects having clear and neat correlated UV and X-ray variations (e.g. ON231) and other objects showing no clear (e.g. AO 0235+164) UV and X-ray correlation. Finally, we also note that our estimates of spectral curvature are in the range of that measured for the HBLs.Comment: 10 pages, 7 figures, published in A&

    Hypovolemic shock due to severe gastrointestinal bleeding in a child taking an herbal syrup

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    We report the case of a 4-years-old boy who was admitted with hypovolemic shock due to a severe gastrointestinal bleeding. The esophagogastroduodenoscopy (EGDS) showed hiatus hernia, erosions and ulcerations of the lower esophagus, possibly due to a gastroesophageal reflux, and a small duodenal erosion. The child was previously healthy and he had never shown any symptoms related to this condition. The only product taken by the child in the previous days was a syrup containing several herbs, among which Filipendula ulmaria (L.) Maxim. and Salix spp. (known to contain salicylates), marketed as food and prescribed by his paediatrician to treat a mild cold accompanied by fever. Quali-quantitative analysis confirmed the presence of salicylates in the syrup. Naranjo algorithm showed a probable correlation between the onset of symptoms and the consumption of the herbal remedy. The child recovered after receiving intensive care. The product was withdrawn from Italian market
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