Improved magnetic charged system search optimization algorithm with application to satellite formation flying

This paper is devoted to the implementation and application of an improved version of the metaheuristic algorithm called magnetic charged system search. Some modifications and novelties are introduced and tested. Firstly, the authors’ attempt is to develop a self-adaptive and user-friendly algorithm which can automatically set all the preliminary parameters (such as the numbers of particles, the maximum iterations number) and the internal coefficients. Indeed, some mathematical laws are proposed to set the parameters and many coefficients can dynamically change during the optimization process based on the verification of internal conditions. Secondly, some strategies are suggested to enhance the performances of the proposed algorithm. A chaotic local search is introduced to improve the global best particle of each iteration by exploiting the features of ergodicity and randomness. Moreover, a novel technique is proposed to handle bad-defined boundaries; in fact, the possibility to self-enlarge the boundaries of the optimization variables is considered, allowing to achieve the global optimum even if it is located on the boundaries or outside. The algorithm is tested through some benchmark functions and engineering design problems, showing good results, followed by an application regarding the problem of time-suboptimal manoeuvres for satellite formation flying, where the inverse dynamics technique, together with the B-splines, is employed. This analysis proves the ability of the proposed algorithm to optimize control problems related to space engineering, obtaining better results with respect to more common and used algorithms in literature

Comment on ‘The latency period of mesothelioma among a cohort of British asbestos workers (1978–2005)': the effect of left censoring

none4noWe read with extreme interest the article by Frost on mesothelioma latency period among asbestos workers (Frost, 2013). Despite the main aim of the study being to investigate ‘the determinants of mesothelioma latency among a cohort of asbestos workers, paying particular attention to indicators of intensity of asbestos exposure’ (Frost, 2013), the reported lack of evidence of an association between duration of exposure and latency attracted some attention. Commenters argued that right censoring occurring in the underlying cohort could have biased an analysis restricted to cases (Consonni et al, 2014; Mirabelli and Zugna, 2014).openFarioli, A; Mattioli, S; Curti, S; Violante, F SFarioli, A; Mattioli, S; Curti, S; Violante, F

Dual-layer spectral CT fusion imaging for lung biopsies: more accurate targets, diagnostic samplings, and biomarker information?

The increasingly widespread use of computed tomography (CT) has increased the number of detected lung lesions, which are then subjected to needle biopsy to obtain histopathological diagnosis. Obtaining high-quality biopsy specimens is fundamental for diagnosis and biomolecular characterisation that guide therapy decision-making. In order to obtain samples with high diagnostic potential, fusion imaging techniques, such as fusion between positron emission tomography and CT, have been introduced to target the biopsy where there more viable neoplastic cells can be sampled. Nowadays, dual-layer spectral CT represents a novel technology enabling an increased tissue characterisation. In particular, Z-effective images, i.e., colour-coded images based on the effective atomic number of tissue components, provide a higher level of discrimination than usual imaged based on x-ray attenuation in Hounsfield units and offer the potential of a better tissue characterisation. Our hypothesis is based on the future use of data provided by spectral CT, in particular by Z-effective images, as a guide for appropriate biopsy sampling for histopathological and biomolecular characterisation in the era of patient tailored-therapy

New fully empirical calibrations of strong-line metallicity indicators in star-forming galaxies

We derive new empirical calibrations for strong-line diagnostics of gas-phase metallicity in local star-forming galaxies by uniformly applying the Te method over the full metallicity range probed by the Sloan Digital Sky Survey (SDSS). To measure electron temperatures at high metallicity, where the auroral lines needed are not detected in single galaxies, we stacked spectra of more than 110 000 galaxies from the SDSS in bins of log[O ii]/Hβ and log[O iii]/Hβ. This stacking scheme does not assume any dependence of metallicity on mass or star formation rate, but only that galaxies with the same line ratios have the same oxygen abundance. We provide calibrations which span more than 1 dex in metallicity and are entirely defined on a consistent absolute Te metallicity scale for galaxies. We apply our calibrations to the SDSS sample and find that they provide consistent metallicity estimates to within 0.05 dex.MC acknowledges financial support from INAF for his PhD fellowship. RM acknowledges support from the ERC Advanced Grant 695671 "QUENCH'' and support from the Science and Technology Facilities Council (STFC). Funding for the SDSS and SDSS-II has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the U.S. Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society and the Higher Education Funding Council for England. The SDSS Web Site is http://www.sdss.org/

Copper deficiency-associated myelopathy in cryptogenic hyperzincemia: A case report

Copper deficiency syndrome is an underestimated cause of posterior myelitis. We describe the case of a 41-year-old woman, who developed a subacute ataxic paraparesis associated with low back pain. Her 3T spine MRI showed a thin hyperintense FS-Echo T2 longitudinally extensive lesion involving the posterior columns of the cervical cord (from C2 to C6). An extensive diagnostic work-up excluded other causes of myelopathy and blood tests pointed out hypocupremia and mild hyperzincemia. Patients affected by this rare form of oligoelement deficiency typically develop progressive posterior column dysfunction with sensory ataxia and spasticity, sometimes associated with sensori-motor polyneuropathy. Clinical and radiological characteristics of posterior myelopathy due to copper deficiency are briefly reviewed. Physicians should be aware of this condition since a prompt introduction of copper supplementation can avoid progression of the neurological damage. (www.actabiomedica.it)

Ileocecal reservoir reconstruction after total mesorectal excision: functional results of the long-term follow-up

Background: The aim of this study is to obtain functional results of the long-term follow-up after TME and ileocecal interposition as rectal replacement. Methods: The study included patients operated on between March 1993 and August 1997 who received an ileocecal interposition as rectal replacement. Follow-up was carried out 3 and 5 years postoperatively. For statistical analysis, the paired t-test, rank test (Wilcoxon), and chi-square or Fisher's exact test were applied; level of significance, P<0.05. Results: Forty-four patients were included in the studies. Of these, five were not available and four patients could not be evaluated (dementia 1, radiation proctitis 1, fistula 1, pouchitis 1). Seventeen patients died during the observation period; 12 died of the disease. Recurrence of the disorder occurred in 2 of 35 patients (5.7%); 26 and 18 patients, 3 and 5 years postoperatively, respectively remained in the study. At 5 years, 78% of the patients were continent; mean stool frequency was 2.5±1.6 per day. Conclusions: Functional results and subjective assessment of ileocecal interposition were constant at 3 and 5 years postoperatively. If construction of a colonic J-pouch is not possible due to lack of colonic length, especially after prior colonic resections, the ileocecal interpositional reservoir may offer an alternative to rectal replacemen

A fully automated pipeline for a robust conjunctival hyperemia estimation

Purpose: Many semi-automated and fully-automated approaches have been proposed in literature to improve the objectivity of the estimation of conjunctival hyperemia, based on image processing analysis of eyes’ photographs. The purpose is to improve its evaluation using faster fully-automated systems and independent by the human subjectivity. Methods: In this work, we introduce a fully-automated analysis of the redness grading scales able to completely automatize the clinical procedure, starting from the acquired image to the redness estimation. In particular, we introduce a neural network model for the conjunctival segmentation followed by an image processing pipeline for the vessels network segmentation. From these steps, we extract some features already known in literature and whose correlation with the conjunctival redness has already been proved. Lastly, we implemented a predictive model for the conjunctival hyperemia using these features. Results: In this work, we used a dataset of images acquired during clinical practice.We trained a neural network model for the conjunctival segmentation, obtaining an average accuracy of 0.94 and a corresponding IoU score of 0.88 on a test set of images. The set of features extracted on these ROIs is able to correctly predict the Efron scale values with a Spearman’s correlation coefficient of 0.701 on a set of not previously used samples. Conclusions: The robustness of our pipeline confirms its possible usage in a clinical practice as a viable decision support system for the ophthalmologists

Pocket-sized, wireless-Bluetooth ultrasound system to perform diagnostic and low-complexity interventional procedures in bedridden patients during the COVID-19 pandemic: from intensive care unit to domiciliary service?

The use of a pocked-sized, wireless-Bluetooth ultrasound portable system with display images presented on a tablet facilitated the work of our radiologists during the first wave of coronavirus disease 2019 (COVID-19) to perform diagnostic and interventional procedures in bedridden patients. The device is equipped with a battery-powered probe without cables that transmits images to a tablet (or a cell phone) through a dedicated App. We hypothesise in future to extend diagnostic and low-complexity interventional procedures from hospitalised patients to at-home patients who are not able to mobilise out of bed or are difficult to transport. This domiciliary service might also reduce the overhead of hospital accesses

p-TSA-Based DESs as &#8220;Active Green Solvents&#8221; for Microwave Enhanced Cyclization of 2-Alkynyl-(hetero)-arylcarboxylates: an Alternative Access to 6-Substituted 3,4-Fused 2-Pyranones

In this paper, we describe the use of p-TSA based Deep Eutectic Solvents (DESs) as alternative environmental-friendly \u201cactive\u201d solvents for the microwave-mediated synthesis of 6-substituted 3,4-fused 2-pyranones, and in particular isocoumarins, starting from 2-alkynyl-(hetero)arylcarboxylates. When the alkyne terminus bears a neutral or an electron-donating group (EDG), the reactions are fast, clean and highly regioselective, to give the 6-endo-dig cyclization products in good to excellent yields. For substrates bearing an electron-withdrawing group (EWG) on the alkyne end, the regioselectivity can be tuned by adding a small amount of silver(I) triflate as co-catalyst. DES was demonstrated to be reusable without loss of efficiency in terms of reaction yields. Based on experimental evidences and previous findings, two competitive mechanisms working simultaneously are proposed to explain the outcomes and the regioselectivity issues