134 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, vsin⁥iv \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 vsin⁥iv \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

    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

    Cancer mortality trends in the Umbria region of Italy 1978–2004: a joinpoint regression analysis

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    BACKGROUND: The aim of the present paper was to analyse cancer mortality in the Umbria region, from 1978 to 2004. Mortality trends depend on a number of factors including exposures, health system interventions, and possibly artefact (e.g. classification change, variations of data completeness). Descriptive data on mortality only allow for generation of hypotheses to explain observed trends. Some clues on the respective role of possible mortality determinants may be found comparing mortality with incidence and survival data. METHODS: Mortality data for the periods 1978–1993 and 1994–2004 were supplied by the National Institute of Statistics (ISTAT) and the Regional Causes of Death Registry (ReNCaM) respectively. Sex and site-specific mortality time trends were analysed by the "joinpoint regression" method. RESULTS: For all sites combined, in both sexes, the standardised rate was first increasing before the end of the eighties and decreasing thereafter. Gastric cancer mortality showed a different trend by gender; that is the rate constantly decreased over the period among females while, for males, it was first increasing up to 1985 and decreasing thereafter. Liver cancer trend showed a pattern similar to gastric cancer. Large bowel cancer showed a gender specific trend, that is it was increasing among males and stable among females. Also lung cancer mortality varied by gender: it started to decline after 1989 among males but was steadily increasing over the study period among women. A decreasing trend for female breast cancer mortality began in 1994. Prostate cancer mortality trend is the only one showing two significant joinpoints: mortality decreased up to 1990, then it increased up to 1998 and, finally, was decreasing. CONCLUSION: Overall cancer mortality was decreasing in both sexes in Umbria and this favourable trend will probably continue and further improve since population screening against breast, cervix, and large bowel cancers were recently introduced. Besides gastric cancer, tobacco-related cancers and prostate cancer mainly contributed to mortality reduction in males, whereas breast cancer mainly contributed to declining mortality in females

    Anti-multiple myeloma potential of secondary metabolites from Hibiscus sabdariffa

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    Multiple myeloma (MM) belongs to hematological cancers and its incidence is increasing worldwide. Despite recent advances in its therapy, MM still causes many deaths every year. In fact, current therapies sometimes fail and are associated with severe adverse eects, including neurotoxicity. As a part of our ongoing efforts to discover new potential therapies against MM, we prepared Hibiscus sabdariffa extracts obtained by a microwave-assisted solvent extraction and investigate their activity by in vitro assays on the RPMI-8226 cell line. The bioguided fractionation of the crude ethanolic extract allowed the identification of HsFC as the most effective extract. We assessed cell viability (MTT and Tripan blue test), cell migration (Boyden chamber assay), and neurotoxicity (DRG neurotoxicity assay). The promising results prompted us to further fractionate HsFC and we obtained two molecules effective against RPMI-8226 cells without neurotoxic effects at their active concentrations. Moreover, both compounds are able to significantly reduce cell migration
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