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Saturn’s rings have been estimated to be as young as about 100 to 400 million years old according to the hypothesis that non-icy micrometeoroid bombardment acts to darken the rings over time and the Cassini observation indicated that the ring particles appear to be relatively clean. These young age estimates assume that the rings formed out of pure water ice particles with a high accretion efficiency of impacting non-icy micrometeoroid material (η≳ 10%). Here we show, using numerical simulations of hypervelocity micrometeoroid impacts on a ring particle, that non-icy material may not be as readily accreted as previously thought. We found that the complete vaporization and expansion of non-icy impactor material on energetic collision with a ring particle leads to the formation of charged nanoparticles and ions that are subsequently removed from the rings through collision with Saturn, gravitational escape or electromagnetic drag into Saturn’s atmosphere. Despite uncertainties in our models that assume no porosity, strength or ring particle granularity, we suggest minimal accretion of non-icy materials would occur following micrometeoroid impact. This pollution resistance mechanism implies a low accretion efficiency (η≲ 1%). Thus we suggest that the apparent youth of Saturn’s rings could be due to pollution resistance, rather than indicative of young formation age.

In this note, the problem of data-driven saturated state feedback design for polynomial nonlinear systems is solved by means of a sum-of-squares (SOS) approach. This new strategy combines recent results in the dissipativity theory and data-driven feedback control using noisy input-state data. SOS optimization is employed in this work for controller design and to deliver an estimate of the closed-loop domain of attraction under saturated feedback. Numerical examples allow the reader to verify the usefulness of our strategy, which is the first in literature to provide a data-driven and dissipativity-based approach for solving the problem of input saturation for continuous-time polynomial systems.

ABSTRACTModelling customer loyalty has been a central issue in customer relationship management, particularly in digital subscription business models. To guarantee news media sustainability, publishers implemented subscription models that need to define successful retention strategies. Thus, churn management has become pivotal in the media subscription business. The present study aims to understand what drives subscribers to churn by performing a Machine Learning approach to model the propensity to churn of online subscribers of a Portuguese newspaper. Two models were developed, tested, and evaluated in two timeframes. The first one considered all Business to Consumer (B2C) subscriptions, and the second only the B2C non-recurring subscriptions. The experimental results revealed important patterns of churners, which allowed the marketing and editorial teams to implement churn prevention and retention measures.

Mobile phones share location records, offering the opportunity to monitor and understand emerging population dynamics in urban centers. With the aim of supporting urban planning, this study introduces a scalable methodology grounded on extracting and organizing spatiotemporal statistics from decomposed population density data. The proposed methodology serves three major purposes: (i) assess the predictability of spatiotemporal citizen density patterns; (ii) detect emerging spatiotemporal trends in population density; and (iii) uncover multi-level seasonality patterns with guarantees of actionability. Additionally, it makes available an open-access tool for deploying the proposed methodology and analyzing mobile phone network data with easy-to-use spatiotemporal visualization and navigation facilities. The results obtained from real-world, large-scale mobile data in Lisbon, Portugal, demonstrate the effectiveness and validity of the proposed methodology in extracting actionable statistics in linear time to guide both tactic and strategic urban planning.

Sjögren's disease is a chronic autoimmune disease with an unmet need for targeted therapies. The aim of the TWINSS study is to evaluate the safety and efficacy of iscalimab, a monoclonal antibody against CD40, in patients with active Sjögren's disease.

This article presents a mass sensor based on a 3-degree-of-freedom (DoF) mode localized piezoelectric bulk acoustic wave (BAW) resonator system operating in the contour extensional mode. It features a quality factor of ~4200 under atmospheric pressure at a resonance frequency of ~6.36 MHz. More than three orders of magnitude enhancement (~1700 times) of the normalized mass sensitivity based on the amplitude ratio (AR) change were achieved compared to that based on the frequency shift. The mass resolution thereof was obtained as 1.2 pg (for the AR change output) and 0.727 pg (for the frequency shift output), respectively. Compared with the previously reported mass sensor based on coupled BAW resonators, the presented device achieved an enhanced performance in terms of both quality factor (~2.37 times higher), stability (~100 and ~3.5 times better for the AR change and frequency shift), and mass resolution (~307 and ~2.97 times better for the AR change and frequency shift). Moreover, the stability of the 3-DoF system with the AR change output was enhanced since there was only a ~1.65-fold difference in the mass resolution in terms of the frequency shift and AR change, compared to ~170-fold in the previous study. Furthermore, the novel device operated with a Q-factor of ~305 in deionized (DI) water, demonstrating the considerable potential of such devices for future sensing applications in a liquid environment.

Catheter ablation for atrial fibrillation (AF) including pulmonary vein isolation and possibly further substrate ablation is the most common electrophysiological procedure. Severe complications are uncommon, but their detailed assessment in a large worldwide cohort is lacking.

Introduction:Recently, university counseling services have been faced with an increasing number of students seeking psychological support. However, human resources and time constraints limit the services to respond adequately. Recently, national guidelines for Mental Health Services in Higher Education recommended the stepped care approach to increase efficiency. The present study aimed to explore the implementation of a stepped care model in a Portuguese public university, analyzing students’ sociodemographic and clinical characteristics, and presenting the flow of the stepped care approach and the students’ waiting periods in each step. Methods:An observational study was conducted in the University of Coimbra’s health services between May 2019 and June 2021. Descriptive statistics were performed to describe the sociodemographic and clinical characteristics of the sample, the flow of the stepped care approach, and students’ waiting periods. Results:We enrolled 295 students in the present study. The findings of this study revealed that over 40% had a clinical diagnosis of anxiety or depressive disorders. In terms of students’ flow within the stepped care model, 82% of students sought psychological help through self-referral. Concerning the implementation of the stepped care model, results have shown that most students wait less than a month to access each step. Discussion/Conclusions:Although preliminary, our results suggest that the stepped care model might be a useful service organization, mainly in a community in which accessibility to services and speed of response are particularly important. Most students being self-referred highlight the importance of direct contact between the university community and the health services. Additionally, anxiety and mood disorders were the most prevalent diagnoses in our sample, which also points to the relevance of a stepped care approach, since other studies have highlighted its advantages for this kind of clinical population.

Introduction: Acromegaly is associated with a possible increased risk of neoplasias, like colorectal cancer (CRC), although magnitude of this risk is unclear. Objectives: Evaluate frequency of colonic adenomatous polyps and CRC in patients with acromegaly at first and subsequent colonoscopies; correlate risk factors of CRC and disease activity of acromegaly with colonoscopy findings and analyze relationship of acromegaly as a risk factor for CRC and the best period for screening this neoplasia. Methods: Patients ≥18 years-old with acromegaly were included. A questionnaire involving characteristics of follow-up of acromegaly and risk factors of CRC was created. Biochemical and colonoscopic data were collected through medical records. Only full-length colonoscopies with satisfactory colonic preparation were included. Results: 123 patients (77 women) were included (mean age at diagnosis of 43.1 years and mean follow-up of 13.7 years). In baseline colonoscopy, 80.5% had non-neoplastic findings, 14.6% non-advanced adenomas, 3.3% advanced adenomas and 1.6% CRC. At end of the study, 3 (2.4%) patients were diagnosed with CRC. No patient under 50 years had a neoplastic lesion on colonoscopy. We observed a positive statistically significant relationship between smoking (p= 0.026), age at diagnosis of acromegaly (p< 0.001), age at baseline colonoscopy (p= 0.002), and risk of adenomas and/or CRC at initial colonoscopy. Conclusions: Smoking and advanced age were positively related to a higher risk of developing premalignant/malignant colonic lesions. Age ( > 50 years) was the most robust variable. Our data suggest that screening age for CRC in acromegaly should be reviewed.

Using a new set of semidefinite constraints called recurrent dissipativity-based inequalities (DBIs), this letter presents an iterative procedure to design polynomial feedback control laws for polynomial nonlinear systems, let it be a static state feedback or a linear static output feedback (SOF) controller one needs to determine. In addition to that, the problem of linear SOF design for linear time-invariant (LTI) systems is solved as well. In the case of polynomial systems, we use sum-of-squares (SOS) programming for controller design and to provide an estimate of the closed-loop domain of attraction. In the case of LTI models, a set of linear matrix inequalities (LMIs) is employed in an iterative strategy to determine a stabilizing gain. Numerical simulations on a few examples borrowed from literature are provided in order to emphasize the advantages of our new dissipativity-based control (DBC) method.

Fear-related pathologies are among the most prevalent psychiatric conditions, having inappropriate learned fear and resistance to extinction as cardinal features. Exposure therapy represents a promising therapeutic approach, the efficiency of which depends on inter-individual variation in fear extinction learning, which neurobiological basis is unknown. We characterized a model of extinction learning, whereby fear-conditioned mice were categorized as extinction (EXT)-success or EXT-failure, according to their inherent ability to extinguish fear. In the lateral amygdala, GluN2A-containing NMDAR are required for LTP and stabilization of fear memories, while GluN2B-containing NMDAR are required for LTD and fear extinction. EXT-success mice showed attenuated LTP, strong LTD and higher levels of synaptic GluN2B, while EXT-failure mice showed strong LTP, no LTD and higher levels of synaptic GluN2A. Neurotrophin 3 (NT3) infusion in the lateral amygdala was sufficient to rescue extinction deficits in EXT-failure mice. Mechanistically, activation of tropomyosin receptor kinase C (TrkC) with NT3 in EXT-failure slices attenuated lateral amygdala LTP, in a GluN2B-dependent manner. Conversely, blocking endogenous NT3-TrkC signaling with TrkC-Fc chimera in EXT-success slices strengthened lateral amygdala LTP. Our data support a key role for the NT3-TrkC system in inter-individual differences in fear extinction in rodents, through modulation of amygdalar NMDAR composition and synaptic plasticity.

In this paper, a sample of tin-free steel tinplate from a tomato paste was analyzed for electrochemical corrosion. The dependence between the variables pH, NaCl content and temperature was evaluated through factorial design. For the body it is possible to verify the presence of Sn thin layer. On the other hand, in the samples of the bottom and the top it is not possible to observe this layer. At low temperatures (below 22 °C) and NaCl concentration from 500 to 2000 ppm the pH do not influence the corrosion rate (CR). Furthermore, for NaCl concentration values below 2000 ppm the temperature does not seem to influence the CR. Thus, working at a chloride concentration below 2000 ppm, the corrosion rate seems to remain the same for changes in pH and temperature.

Austenitic stainless steels are widely used due to their resistance to corrosion and to the possibility of using them at temperatures above 600 °C. Plasma nitriding and nitrocarburizing consist of a thermochemical process that introduces nitrogen and nitrogen/carbon, in atomic form, allowing the formation of second phases of these elements with the substrate. These thermochemical treatments of plasma nitriding and nitrocarburizing were performed on austenitic stainless steel AISI 312 at temperatures of 400 °C and 500 °C, obtaining thicknesses of around 12 μm and 24 μm, respectively. Mechanical properties of indentation were obtained using a Hit 300 nanoindenter (Anton Paar), in a load-unload cycle and with a depth of up to 10% of the layer, with Berkovich indenter. The elastic moduli obtained for the nitrided layers were 281 ± 21 GPa (400 °C) and 163 ± 32 GPa (500 °C) and for the nitrocarburized were 214 ± 12 GPa (400 °C) and 169 ± 25 GPa (500 °C). The indentation nanohardness obtained for the nitrided layers were 14.1 ± 1.0 GPa (400 °C) and 3.5 ± 1.2 GPa (500 °C) and for the nitrocarburized layers were 10.8 ± 0.8 GPa (400 °C) and 4.3 ± 1.2 GPa (500 °C). Therefore, these results indicate slightly higher values for the two mechanical properties indentation (elastic modulus and nanohardness) at 400 °C than at 500 °C caused by nitriding compared to nitrocarburizing treatment; however, when considering the percentages of standard deviations, the treatments at 500 °C present much higher values for these properties, as compared to the treatments at 400 °C, a behavior associated with the presence of chromium and iron nitrides.

Purpose: This cross-sectional study aimed to assess bone mineral density (BMD), bone microarchitecture and fracture prevalence in women with chronic postsurgical hypoparathyroidism (hypoPT). Methods: Twenty-seven women with postsurgical hypoPT and 44 age-matched healthy women were included. Dual-energy X-ray absorptiometry was used to evaluate areal BMD and vertebral fracture assessment. High-resolution peripheral quantitative computed tomography assessed microarchitecture and volumetric BMD at the distal radius and tibia. Biochemical parameters, including fibroblast growth factor 23, C-terminal cross-linking telopeptide of type I collagen (ICTP), and procollagen type I N-terminal propeptide (P1NP), were also measured. Previous low-impact fractures were assessed and the 10-year fracture risk was estimated using the FRAX tool for the Brazilian population. Results: No participant had prevalent clinical fractures, and both groups showed low risk for major and hip based on FRAX tool, but two hypoPT patients had moderate to severe morphometric vertebral fractures. Women with hypoPT had increased aBMD in the lumbar spine, femoral neck and total hip (p< 0.05) and higher cortical vBMD in the radius (p= 0.020) and tibia (p< 0.001). Trabecular bone was not affected. Both P1NP and ICTP suggested low bone turnover rates, but no significant correlation was observed between bone density or microstructure and any of the biochemical parameters. Conclusions: The prevalence of fragility fractures was low in HypoPT women and compatible with low fracture risk estimated by the FRAX tool. Patients had a higher aBMD and cortical vBMD than those of healthy control women, but the association with decreased bone turnover remains unclear.

With the advancement technology for reinforced concrete structures, it becomes increasingly feasible to use this technology for steel structures. The objective of this work is to present the formulation of the optimization problem of steel beams with external pretension with straight or polygonal tracing cables, considering the environmental and economic impacts. For the objective function formulation, the minimization of CO2emission and cost in the design of the structure were considered. As constraints were established the states limits imposed by ABNT NBR 8800:2008. The program was developed within the MATLAB Platform (MATLAB®. Guia do usuário R2016a (2016) The Math Works Inc) and the optimization problem solution was obtained through the native genetic algorithms method. Routine validation was performed using examples found in the literature and an analysis of the predominant collapse modes was performed. The results indicate that monosymmetric profiles have gains when it comes to reducing CO2emissions and cost when compared to doubly symmetrical profiles, in addition it was observed that straight cables generate better values of CO2emission and cost when compared to polygonal cables.

•TERRA is repressed in primary human hematopoietic cells (in the bone marrow and peripheral blood), regardless of their telomere lengths.•TERRA is dysregulated in a subset of AML characterized by higher R-loop formation and low TERTand RNAseH2expression.