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The purpose of this work is to develop a procedure to obtain the normal modes of a coronal loop from time-dependent numerical simulations with the aim of better understanding observed transverse loop oscillations. To achieve this goal, in this paper we present a new method and test its performance with a problem for which the normal modes can be computed analytically. In a follow-up paper, the application to the simulations of Rial et al. is tackled. The method proceeds iteratively and at each step consists of (i) a time-dependent numerical simulation followed by (ii) the Complex Empirical Orthogonal Function (CEOF) analysis of the simulation results. The CEOF analysis provides an approximation to the normal mode eigenfunctions that can be used to set up the initial conditions for the numerical simulation of the following iteration, in which an improved normal mode approximation is obtained. The iterative process is stopped once the global difference between successive approximate eigenfunctions is below a prescribed threshold. The equilibrium used in this paper contains material discontinuities that result in one eigenfunction with a jump across these discontinuities and two eigenfunctions whose normal derivatives are discontinuous there. After six iterations, the approximations to the frequency and eigenfunctions are accurate to ≲0.7% except for the eigenfunction with discontinuities, which displays a much larger error at these positions. [ABSTRACT FROM AUTHOR]

Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show that the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves). [ABSTRACT FROM AUTHOR]

The spatial variation of physical quantities, such as the mass density, across solar atmospheric waveguides governs the timescales and spatial scales for wave damping and energy dissipation. The direct measurement of the spatial distribution of density, however, is difficult, and indirect seismology inversion methods have been suggested as an alternative. We applied Bayesian inference, model comparison, and model-averaging techniques to the inference of the cross-field density structuring in solar magnetic waveguides using information on periods and damping times for resonantly damped magnetohydrodynamic transverse kink oscillations. Three commonly employed alternative profiles were used to model the variation of the mass density across the waveguide boundary. Parameter inference enabled us to obtain information on physical quantities such as the Alfvén travel time, the density contrast, and the transverse inhomogeneity length scale. The inference results from alternative density models were compared and their differences quantified. Then, the relative plausibility of the considered models was assessed by performing model comparison. Our results indicate that the evidence in favor of any of the three models is minimal, unless the oscillations are strongly damped. In such a circumstance, the application of model-averaging techniques enables the computation of an evidence-weighted inference that takes into account the plausibility of each model in the calculation of a combined inversion for the unknown physical parameters. [ABSTRACT FROM AUTHOR]

Background: A 25-hydroxyvitamin D (25OHD) may exert immunomodulatory effects on respiratory health, which may translate to improvements in exercise physiology. Thus, we aimed to investigate whether plasma 25OHD is associated with lung function and aerobic fitness in people with cystic fibrosis (pwCF)., Methods: A multicentre retrospective review of pwCF (> 9 years old) attending the Royal Hospital for Sick Children (Edinburgh) or Wessex CF-Unit (Southampton) was performed between July 2017 and October 2019. Demographic and clinical data were collected. Plasma 25OHD measured closest in time to clinical cardiopulmonary exercise testing and/or spirometry [forced expiratory volume (FEV 1 )% predicted] was recorded. Pancreatic insufficiency was diagnosed based on faecal elastase of < 100 µg g -1 . We performed multiple-regression analysis with aerobic fitness outcomes [peak oxygen uptake (VO 2 peak )] and FEV 1 % predicted as primary outcomes., Results: Ninety pwCF [mean ± SD age: 19.1 ± 8.6 years, 54 (60%) children, 48 (53%) males and 88 (98%) Caucasian] were included. 25OHD deficiency and insufficiency was 15 (17%) and 44 (49%), respectively. 25OHD deficiency and insufficiency was significantly associated with pancreatic insufficiency (χ 2  = 4.8, p = 0.02). Plasma 25OHD was not significantly associated with FEV 1 % predicted (r 2  = 0.06, p = 0.42, 95% CI = -0.09 to 0.19) or VO 2 peak (r 2  = 0.04, p = 0.07, 95% CI = -011 to 0.005) in all pwCF. However, 25OHD was significantly associated with both FEV 1 % (r 2  = 0.15, p = 0.02, 95% CI = 1.99-2.64) and VO 2 peak (r 2  = 0.13, p = 0.05, 95% CI = -0.26 to -0.005) in the paediatric cohort., Conclusions: We showed that 25OHD is associated with improved lung function and aerobic fitness in children and adolescents with CF. Mechanistic and high-quality prospective studies including both lung function and aerobic fitness as primary outcomes are now warranted., (© 2021 The British Dietetic Association Ltd.)

Vaccines may induce positive non-specific immune responses to other pathogens. This study aims to evaluate if influenza vaccination in the 2019-2020 season had any effect on the risk of SARS-CoV-2 confirmed infection in a cohort of health workers. During the first SARS-CoV-2 epidemic wave in Spain, between March and May 2020, a cohort of 11,201 health workers was highly tested by RT-qPCR and/or rapid antibody test when the infection was suspected. Later in June, 8665 of them were tested for total antibodies in serum. A total of 890 (7.9%) health workers were laboratory-confirmed for SARS-CoV-2 infection by any type of test, while no case of influenza was detected. The adjusted odds ratio between 2019-2020 influenza vaccination and SARS-CoV-2 confirmed infection was the same (1.07; 95% CI, 0.92-1.24) in both comparisons of positive testers with all others (cohort design) and with negative testers (test-negative design). Among symptomatic patients tested by RT-qPCR, the comparison of positive cases and negative controls showed an adjusted odds ratio of 0.86 (95% CI, 0.68-1.08). These results suggest that influenza vaccination does not significantly modify the risk of SARS-CoV-2 infection. The development of specific vaccines against SARS-CoV-2 is urgent.

Background: The development of cystic fibrosis (CF)-related diabetes (CFRD) in paediatric groups is associated with a reduced aerobic fitness. However, this has yet to be investigated in adults with more severe lung disease., Methods: Cardiopulmonary exercise and glycaemic control tests were retrospectively analysed in 46 adults with CF (age: 26.9 y [range: 16.3-66.5 y]; forced expiratory volume in 1s: 65.3% [range: 26.8-105.7%]; 26 males), diagnosed with CFRD (n = 19), impaired glucose tolerance (IGT; n = 8) or normal glucose tolerance (NGT; n = 19)., Results: Maximal oxygen uptake (V˙O 2max ) was reduced in adults with IGT and CFRD compared to their age- and gender-matched counterparts with NGT (p < 0.05); however, there was no difference when lung function was included as a covariate (all p > 0.05). V˙O 2max was greater in adults who experienced post-reactive hypoglycaemia vs. NGT without hypoglycaemia (p < 0.05). The frequency of ventilatory limitation (84%, 63% and 37%, respectively; p < 0.05) but not ventilation-perfusion mismatch (42%, 38% and 16%, respectively; p > 0.05), was greater with CFRD and IGT vs. NGT. There was also no difference in arterial oxygen saturation changes between groups (p > 0.05). Gender and body mass index were significant predictors of V˙O 2max (adjusted R 2  = 0.37, p < 0.01), but glycaemic control did not explain additional variance (p > 0.05)., Conclusions: Adults with CF-related dysglycaemia had a reduced V˙O 2max compared to age- and gender-matched counterparts, due to a greater degree of CF lung disease in these populations., Competing Interests: Declaration of Competing Interest None., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

Tuna are globally distributed species of major commercial importance and some tuna species are a major source of protein in many countries. Tuna are characterized by dynamic distribution patterns that respond to climate variability and long-term change. Here, we investigated the effect of environmental conditions on the worldwide distribution and relative abundance of six tuna species between 1958 and 2004 and estimated the expected end-of-the-century changes based on a high-greenhouse gas concentration scenario (RCP8.5). We created species distribution models using a long-term Japanese longline fishery dataset and two-step generalized additive models. Over the historical period, suitable habitats shifted poleward for 20 out of 22 tuna stocks, based on their gravity centre (GC) and/or one of their distribution limits. On average, tuna habitat distribution limits have shifted poleward 6.5 km per decade in the northern hemisphere and 5.5 km per decade in the southern hemisphere. Larger tuna distribution shifts and changes in abundance are expected in the future, especially by the end-of-the-century (2080-2099). Temperate tunas (albacore, Atlantic bluefin, and southern bluefin) and the tropical bigeye tuna are expected to decline in the tropics and shift poleward. In contrast, skipjack and yellowfin tunas are projected to become more abundant in tropical areas as well as in most coastal countries' exclusive economic zones (EEZ). These results provide global information on the potential effects of climate change in tuna populations and can assist countries seeking to minimize these effects via adaptive management., (© 2019 John Wiley & Sons Ltd.)

This study presents a methodology for the automated analysis of commercial medium-range sonar signals for detecting presence/absence of bluefin tuna (Tunnus thynnus) in the Bay of Biscay. The approach uses image processing techniques to analyze sonar screenshots. For each sonar image we extracted measurable regions and analyzed their characteristics. Scientific data was used to classify each region into a class ("tuna" or "no-tuna") and build a dataset to train and evaluate classification models by using supervised learning. The methodology performed well when validated with commercial sonar screenshots, and has the potential to automatically analyze high volumes of data at a low cost. This represents a first milestone towards the development of acoustic, fishery-independent indices of abundance for bluefin tuna in the Bay of Biscay. Future research lines and additional alternatives to inform stock assessments are also discussed., Competing Interests: The authors have declared that no competing interests exist.

Questions surrounding the chronology, place, and character of the initial human colonization of the Americas are a long-standing focus of debate. Interdisciplinary debate continues over the timing of entry, the rapidity and direction of dispersion, the variety of human responses to diverse habitats, the criteria for evaluating the validity of early sites, and the differences and similarities between colonization in North and South America. Despite recent advances in our understanding of these issues, archaeology still faces challenges in defining interdisciplinary research problems, assessing the reliability of the data, and applying new interpretative models. As the debates and challenges continue, new studies take place and previous research reexamined. Here we discuss recent exploratory excavation at and interdisciplinary data from the Monte Verde area in Chile to further our understanding of the first peopling of the Americas. New evidence of stone artifacts, faunal remains, and burned areas suggests discrete horizons of ephemeral human activity in a sandur plain setting radiocarbon and luminescence dated between at least ~18,500 and 14,500 cal BP. Based on multiple lines of evidence, including sedimentary proxies and artifact analysis, we present the probable anthropogenic origins and wider implications of this evidence. In a non-glacial cold climate environment of the south-central Andes, which is challenging for human occupation and for the preservation of hunter-gatherer sites, these horizons provide insight into an earlier context of late Pleistocene human behavior in northern Patagonia.

Magnetic waves are a relevant component in the dynamics of the solar atmosphere. Their significance has increased because of their potential as a remote diagnostic tool and their presumed contribution to plasma heating processes. We discuss our current understanding of coronal heating by magnetic waves, based on recent observational evidence and theoretical advances. The discussion starts with a selection of observational discoveries that have brought magnetic waves to the forefront of the coronal heating discussion. Then, our theoretical understanding of the nature and properties of the observed waves and the physical processes that have been proposed to explain observations are described. Particular attention is given to the sequence of processes that link observed wave characteristics with concealed energy transport, dissipation and heat conversion. We conclude with a commentary on how the combination of theory and observations should help us to understand and quantify magnetic wave heating of the solar atmosphere., (© 2015 The Author(s) Published by the Royal Society. All rights reserved.)

Background: Chyle leak complicates 1.3-10.8 % of pancreatic resections. Universal use of parenteral nutrition following pancreatic resection may reduce the incidence of chyle leak. However, this denies the majority of patients who do not develop chyle leak the benefits of enteral nutrition (EN). The present study aimed to identify risk factors for chyle leak following pancreatic resection within a single institution where EN was used universally., Methods: All patients who underwent pancreatic resection between January 2007 and December 2010 were identified retrospectively. The patients had been treated according to a common unit protocol of enteral feeding; those developing chyle leak were switched to a medium-chain triglyceride (MCT) regimen. Clinical progress and recovery after surgery was evaluated. Multivariate analysis was performed to identify factors associated with chyle leak., Results: A total of 245 patients underwent major pancreatic resection (231 pancreatoduodenectomy, 14 total pancreatectomy). Chyle leak complicated 40 cases (16.3 %). After multivariate analysis, both extensive lymphadenectomy (P = 0.002) and postoperative portal/mesenteric venous thrombosis (PVT) (P = 0.009) were independently linked with a higher incidence of chyle leak. The development of chyle leak was not associated with poorer survival or prolonged duration of hospital stay. It was associated with a significantly increased duration of abdominal drainage and reduced likelihood of early hospital discharge (P = 0.026)., Conclusions: Universal use of enteral feeding is associated with a high rate of chyle leak following pancreatic resection. Patients undergoing extensive lymphadenectomy or those who develop PVT postoperatively are at increased risk. Development of chyle leak was not associated with additional morbidity or mortality following implementation of an MCT regimen. The implication is that reactive management of chyle leak with conversion to a MCT predominant diet is safe.

Background: In dentistry, allergic reactions to Ti implants have not been studied, nor considered by professionals. Placing permanent metal dental implants in allergic patients can provoke type IV or I reactions. Several symptoms have been described, from skin rashes and implant failure, to non-specific immune suppression., Objective: Our objective was to evaluate the presence of titanium allergy by the anamnesis and examination of patients, together with the selective use of cutaneous and epicutaneous testing, in patients treated with or intending to receive dental implants of such material., Material and Methods: Thirty-five subjects out of 1500 implant patients treated and/or examined (2002-2004) were selected for Ti allergy analysis. Sixteen presented allergic symptoms after implant placement or unexplained implant failures [allergy compatible response group (ACRG)], while 19 had a history of other allergies, or were heavily Ti exposed during implant surgeries or had explained implant failures [predisposing factors group (PFG)]. Thirty-five controls were randomly selected (CG) in the Allergy Centre. Cutaneous and epicutaneous tests were carried out., Results: Nine out of the 1500 patients displayed positive (+) reactions to Ti allergy tests (0.6%): eight in the ACRG (50%), one in the PFG (5.3%)(P=0.009) and zero in the control group. Five positives were unexplained implant failures (five out of eight)., Conclusions: Ti allergy can be detected in dental implant patients, even though its estimated prevalence is low (0.6%). A significantly higher risk of positive allergic reaction was found in patients showing post-op allergy compatible response (ACRG), in which cases allergy tests could be recommended.

In the last decade we have been overwhelmed by an avalanche of discoveries of magnetohydrodynamic (MHD) waves by the Solar and Heliospheric Observatory and Transition Region and Coronal Explorer observatories. Both standing and propagating versions of fast magnetoacoustic and slow magnetoacoustic MHD waves have been detected. Information on the damping times and damping distances of these waves is less detailed and less accurate than that on periods and amplitudes. Nevertheless, observations show the damping times and damping lengths are often short. Also, different types of MHD waves in different types of magnetic structures likely require different damping mechanisms. The phenomenon of fast damping is well documented for the standing fast magnetosonic kink waves in coronal loops. This paper concentrates on standing fast magnetosonic waves. It reports on results on periods and damping times due to resonant absorption in one-dimensional and two-dimensional models of coronal loops. Special attention is given to multiple modes.

Resonantly damped fast kink quasi-modes are computed in fully resistive magnetohydrodynamics for fully non-uniform two-dimensional equilibrium models. The equilibrium model is a straight cylindrically symmetric flux tube with a plasma density that is non-uniform both across and along the loop. The variation of density across the loop can cover the whole loop. Our results indicate that the period and damping of coronal loop oscillations mainly depend on the density contrast and the inhomogeneity length-scale and are independent of the details of longitudinal stratification. This study extends previous studies on coronal loop oscillations, and allows for a better comparison between observations and theory.

Aim: A randomised clinical trial was designed to compare the immediate efficacy (48-96 h) of two treatments with bioadhesive gels with different concentrations of potassium nitrate (NK 5% versus NK 10%) on dentine hypersensitivity (DH). We evaluated DH by means of the use of the evaporative stimulus (ES), as the main outcome, using a placebo control group as reference., Patients and Methods: Forty-five consecutive patients who, after stimulation with a blast of air, had at least one tooth with DH > or = 2 according to the verbal ratings scale (VRS) scale were selected. They were randomly treated with a bioadhesive gel with 5% NK, 10% NK or a placebo gel without NK. The DH was evaluated at baseline, days 2, 4, 7 and 14 by an examiner blind to the procedure. The response to the ES with a blast of air, to the tactile stimulation with a probe and the subjective evaluation of the patient measured on the VRS scale were recorded. Statistical analysis was made using the Kruskal-Wallis test., Results: A greater reduction of DH after ES was observed after 48 h of treatment in the NK10% group (35.8%) compared to the NK5% group and placebo group (11.8% and 13.4%, respectively). This difference increased significantly at 96 h (p=0.003). No significant differences were observed for the other variables. These preliminary results may support the usefulness of an NK 10% gel to reduce the DH after stimulation with a blast of air during the first 4 days of its appearance.

In regard to the limited literature on the subject, and the contradictions observed, we can not conclude that the types of manual brushes produce clinically important effects on the patients' gingival health, or that these effects can be detected consistently. However, the best results have been obtained with new brush designs, and future studies are necessary to clarify the existing contradictions. There is a clear need of long-term studies which comparatively evaluate the ability to reduce gingivitis and plaque with the newly designed brushes. On the other hand, there is evidence that supports the use of powered toothbrushes in the general population, especially those of the oscillating-rotating and counter-rotational type, as they have shown their ability to reduce gingival bleeding or inflammation, and dental plaque with greater efficacy than manual brushes. There is a clear need of long-term trials on the efficacy of powered brushes in orthodontic patients. With the existing studies we can conclude that there is limited evidence that orthodontic patients using a powered toothbrush show a slight, but significant, reduction of bleeding, compared with users of manual brushes. No conclusion can be made concerning the type of brush to be used. The techniques of interproximal oral hygiene, fundamentally the use of dental floss and interproximal brushes, appear to add additional benefits, in terms of plaque reduction, when they are associated with conventional manual brushes. Further long-term studies are necessary to confirm their efficacy in the reduction of gingival bleeding or inflammation. The choice of the type of technique must be made in relation to the characteristics of the patient: dental floss could be indicated in individuals with closed interdental spaces, and inter-proximal brushes in periodontal patients, or in those with open embrasures.

Background: Power-driven toothbrushes (PDT) have been designed to improve the efficacy of oral hygiene. It is not clear how they compare in efficacy with manual toothbrushes in cause-related periodontal therapy., Objectives: To evaluate the effectiveness of the use of a PDT as compared with a manual toothbrush (MT), in terms of gingival bleeding or inflammation resolution, in cause-related periodontal therapy., Material and Methods: An electronic (MEDLINE and Cochrane Oral Health Group Specialised Trials Register) and a manual search were made to detect studies which permitted the evaluation of the efficacy of PDT in the reduction of gingival bleeding or inflammation, and their effect on other secondary variables. Only randomized studies in adults, published in English up to June 2001, which compared a PDT with an MT, and evaluated the evolution of gingival bleeding or inflammation were included. The selection of articles, extraction of data and assessment of validity were made independently by several reviewers., Results: Twenty-one studies were finally selected. The heterogeneity of the data prevented a quantitative analysis. A higher efficacy in the reduction of gingival bleeding or inflammation in the PDT patients was detected in 10 studies. This effect appears to be related to the capacity to reduce plaque, and is more evident in counter-rotational and oscillating-rotating brushes. No solid evidence was found for a higher efficacy of sonic brushes. In short-term studies with prophylaxis after initial examination, independently of the type of PDT tested, no significant differences were found., Conclusion: The use of PDT, especially counter-rotational and oscillating-rotating brushes, can be beneficial in reducing the levels of gingival bleeding or inflammation. There is a need for methodological homogeneity in future studies in this field to enable quantitative analysis of their results.