Fatigue Assessment of Moorings for Floating Offshore Wind Turbines by Advanced Spectral Analysis Methods

The fatigue assessment of mooring lines for floating offshore wind turbines represents a challenging issue not only for the reliable design of the stationkeeping system but also for the economic impact on the installation and maintenance costs over the entire lifetime of the offshore wind farm. After a brief review about the state-of-art, the nonlinear time-domain hydrodynamic model of floating offshore wind turbines moored by chain cables is discussed. Subsequently, the assessment of the fatigue damage in the mooring lines is outlined, focusing on the combined-spectrum approach. The relevant fatigue parameters, due to the low-and wave-frequency components of the stress process, are estimated by two different methods. The former is based on the time-domain analysis of the filtered stress process time history. The latter, instead, is based on the spectral analysis of the stress process by two advanced methods, namely the Welch and Thomson ones. Subsequently, a benchmark study is performed, assuming as reference floating offshore wind turbine the OC4-DeepCWind semisubmersible platform, equipped with the 5 MW NREL wind turbine. The cumulative fatigue damage is determined for eight load conditions, including both power production and parked wind turbine situations. A comparative analysis between time-domain and spectral analysis methods is also performed. Current results clearly show that the endorsement of advanced spectral analysis methods can be helpful to improve the reliability of the fatigue life assessment of mooring lines

Measurement of sea waves

Sea waves constitute a natural phenomenon with a great impact on human activities, and their monitoring is essential for meteorology, coastal safety, navigation, and renewable energy from the sea. Therefore, the main measurement techniques for their monitoring are here reviewed, including buoys, satellite observation, coastal radars, shipboard observation, and microseism analysis. For each technique, the measurement principle is briefly recalled, the degree of development is outlined, and trends are prospected. The complementarity of such techniques is also highlighted, and the need for further integration in local and global networks is stressed

Sars-cov-2 detection in fecal sample from a patient with typical findings of covid-19 pneumonia on ct but negative to multiple sars-cov-2 rt-pcr tests on oropharyngeal and nasopharyngeal swab samples

Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests’ results on samples from the upper respiratory tract

Could SARS-CoV-2 Have Bacteriophage Behavior or Induce the Activity of Other Bacteriophages?

SARS-CoV-2 has become one of the most studied viruses of the last century. It was assumed that the only possible host for these types of viruses was mammalian eukaryotic cells. Our recent studies show that microorganisms in the human gastrointestinal tract affect the severity of COVID-19 and for the first time provide indications that the virus might replicate in gut bacteria. In order to further support these findings, in the present work, cultures of bacteria from the human microbiome and SARS-CoV-2 were analyzed by electron and fluorescence microscopy. The images presented in this article, in association with the nitrogen (15N) isotope-labeled culture medium experiment, suggest that SARS-CoV-2 could also infect bacteria in the gut microbiota, indicating that SARS-CoV-2 could act as a bacteriophage. Our results add new knowledge to the understanding of the mechanisms of SARS-CoV-2 infection and fill gaps in the study of the interactions between SARS-CoV-2 and non-mammalian cells. These findings could be useful in suggesting specific new pharmacological solutions to support the vaccination campaign

Comparison of emotional approaches of medical doctors against COVID-19 pandemic: Eastern and Western Mediterranean countries

Background: Pandemics are states of disease that occur worldwide and sharply increase in populations. It causes life events which trigger anxiety, depression, anger, sleep deprivation, emotional distress and stress. World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a pandemic on March 11, pointing to the over 118,000 cases in over 110 countries. Many healthcare workers became ill during the pandemic and some among them died. In this study, we aimed to evaluate and compare level of stress against COVID-19 pandemic among doctors from Turkey and Italy. Methods: This research is a cross-sectional study in which Perceived Stress Scale (PSS-10) and Secondary Traumatic Stress Scale (STSS) are administered online via social networks. All data collection tools were delivered to individuals between 1 and 15 June 2020 and filled in online with Google Forms application. In total, 618 individuals were included in this study and all of them were medical doctors. Results: Higher PS and STS levels were found related to female gender, being married, working in pandemic hospital and older ages. Stress levels were found statistically higher in Turkish doctors when compared to Italian doctors for both stress scales (Turkish/Italian PSS:20.18 ± 7.90/ 19.35 ± 6.71, STSS: 44.19 ± 13.29/ 38.83 ± 13.74). Conclusion: The number of doctors per 1000 of population is lower and per capita visits to a physician are higher in Turkey when compared to Italy. Besides pandemic, these heavier working conditions, increased weekly working hours can cause stress for Turkish doctors. Reporting information such this study is important and international collaborations are essential to plan future prevention strategies. We need to strengthen international ties and build more international collaborations rather than staying within our national silos. Additionally, interventions to promote mental well-being in health care professionals exposed to COVID-19 need to be immediately implemented

Chemical composition and biological activities of oregano and lavender essential oils

Folk medicine uses wild herbs, especially from the Lamiaceae family, such as oregano and lavender, in the treatment of many diseases. In the present study, we investigated the antibacterial activity of the essential oils of Origanum glandulosum Desf. and Lavandula dentata L. against multidrug-resistant Klebsiella pneumoniae strains. The chemical composition of essential oils and their effect on the ultrastructure of the tested bacteria and on the release of cellular components that absorb at 260 nm were studied. Furthermore, the cytotoxicity and the production of reactive oxygen species in human lymphocytes treated with essential oils were evaluated. Thymol (33.2%) was the major constituent in O. glandulosum, and β-pinene (17.3%) was the major constituent in L. dentata. We observed ultrastructural damage in bacteria and increased release of cellular material. Furthermore, ROS production in human lymphocytes treated with essential oils was lower than in untreated lymphocytes and no cytotoxicity was observed. Therefore, the essential oils of lavender and oregano could be used as a source of natural antibacterial and antioxidant agents with potential pharmacological applications

The geometrical nature of optical resonances : from a sphere to fused dimer nanoparticles

We study the electromagnetic response of smooth gold nanoparticles with shapes varying from a single sphere to two ellipsoids joined smoothly at their vertices. We show that the plasmonic resonance visible in the extinction and absorption cross sections shifts to longer wavelengths and eventually disappears as the mid-plane waist of the composite particle becomes narrower. This process corresponds to an increase of the numbers of internal and scattering modes that are mainly confined to the surface and coupled to the incident field. These modes strongly affect the near field, and therefore are of great importance in surface spectroscopy, but are almost undetectable in the far field

Is parental longevity associated with the cardiovascular risk and the successful aging of their offspring? Results from the multinational MEDIS study

The aim of the present study was to evaluate the role of parental longevity and parental cardiovascular disease (CVD) history in CVD risk and successful aging of a random sample of older adults living in the Mediterranean basin and who participated in the MEDiterranean Islands (MEDIS) study. During 2005 to 2011, 2663 elders were voluntarily enrolled. A multidimensional successful aging index consisting of 10 components was used. Paternal and maternal longevity was defined as those older participants of whom both parents lived above the age of 90. The burden of CVD-related factors (CVD-RFs) was calculated as the total score of 4 major CVD-RFs (range 0-4). After adjustment, parental longevity was inversely associated with the burden of CVD-RFs ( P = .04). Moreover, parental longevity was positively associated with the older adults' successful aging score (β-coefficient [95% confidence interval]: .38 [0.06-0.71]). Parent's long living was revealed as an important factor for successful aging and for reduced CVD risk, suggesting that further research is needed in the genetic predisposition of longevity

Regulatory noncoding and predicted pathogenic coding variants of ccr5 predispose to severe covid-19

Genome-wide association studies (GWAS) found locus 3p21.31 associated with severe COVID-19. CCR5 resides at the same locus and, given its known biological role in other infection diseases, we investigated if common noncoding and rare coding variants, affecting CCR5, can predispose to severe COVID-19. We combined single nucleotide polymorphisms (SNPs) that met the suggestive significance level (P ≤ 1 × 10−5 ) at the 3p21.31 locus in public GWAS datasets (6406 COVID-19 hospitalized patients and 902,088 controls) with gene expression data from 208 lung tissues, Hi-C, and Chip-seq data. Through whole exome sequencing (WES), we explored rare coding variants in 147 severe COVID-19 patients. We identified three SNPs (rs9845542, rs12639314, and rs35951367) associated with severe COVID-19 whose risk alleles correlated with low CCR5 expression in lung tissues. The rs35951367 resided in a CTFC binding site that interacts with CCR5 gene in lung tissues and was confirmed to be associated with severe COVID-19 in two independent datasets. We also identified a rare coding variant (rs34418657) associated with the risk of developing severe COVID-19. Our results suggest a biological role of CCR5 in the progression of COVID-19 as common and rare genetic variants can increase the risk of developing severe COVID-19 by affecting the functions of CCR5