20 research outputs found
Nonlinear Optimization of a New Polynomial Tyre Model.
Tyre behavior is strongly nonlinear. This article presents the validation of a new
polynomial tyre model with real test data, analyzing the convergence properties during the
optimization process to calculate the values of the parameters. A multivariate model with 13
parameters is shown, including normal load and camber angle. The article reviews the methods of
getting polynomial approximations of the magic formula tyre model used to develop the new
polynomial model, the numerical optimization methods who calculate the parameters of the model
from real test data and it explains how the terms of the Jacobian matrix are modified when we
impose constraints to the curve; this can be useful to improve the adjustment in some areas of the
curve. The convergence properties are shown both for the magic formula tyre model and for this
polynomial tyre model.
The proposed model presents a fast convergence both in one and in 3 variables. This is an additional
advantage to its excellent analytical properties, the model is very easy to compute and can be easily
derived and integrated. It is very well adapted for real time computing.pre-print534 K
Fast Computing on Vehicle Dynamics Using Chebyshev Series Expansions.
This article focusses on faster computation techniques
to integrate mechanical models in electronic advanced active
safety applications. It shows the different techniques of
approximation in series of functions and differential equations
applied to vehicle dynamics. This allows the achievement of
approximate polynomial and rational solutions with a very fast
and efficient computation. Firstly, the whole theoretical basic
principles related to the techniques used are presented:
orthogonality of functions, function expansion in Chebyshev and
Jacobi series, approximation through rational functions, the
Minimax-Remez algorithm, orthogonal rational functions
(ORF’s) and the perturbation of dynamic systems theory, that
reduces the degree of the expansion polynomials used.
As an application, it is shown the obtaining of approximate
solutions to the longitudinal dynamics, vertical dynamics, steering
geometry and a tyre model, all obtained through development in
series of orthogonal functions with a computation much faster
than those of its equivalents in the classic vehicle theory. These
polynomial partially symbolic solutions present very low errors
and very favourable analytical properties due to their simplicity,
becoming ideal for real time computation as those required for
the simulation of evasive manoeuvres prior a crash. This set of
techniques had never been applied to vehicle dynamics before.pre-print748 K
Gender differences in anxiety, attitudes, and fear among nursing undergraduates coping with CPR training with PPE kit for COVID
Producción CientíficaBackground: The aim of this study was to examine the attitudes, fears, and anxiety level of nursing students faced with a critical clinical simulation (cardiopulmonary reanimation) with and without personal protective equipment (PPE). Methods: A pilot before–after study as conducted from 21 to 25 June 2021, with 24 students registered in the nursing degree of the Faculty of Health Sciences of the Castilla-La Mancha University (UCLM) in the city of Talavera de la Reina (Toledo, Spain). From 520 possible participants, only 24 were selected according to the exclusion and inclusion criteria. The STAI Manual for the State-Trait Anxiety Inventory, a self-evaluation questionnaire, was used to study trait STAI (basal anxiety), trait STAI before CPR, state STAI after CPR, total STAI before CPR, and total STAI after CPR as the main variables. A t-test was used to study the STAI variables according to sex and the physiological values related to the anxiety level of participants. An ANOVA statistical test was used to perform a data analysis of the STAI variables. Results: A total of 54.2% of participants (IC 95% 35.1–72.1) suffered from global anxiety before the cardiopulmonary reanimation maneuvers (CPR). The results of the STAI before CPR maneuvers showed significant differences according to gender in state anxiety (p = 0.04), with a higher level of anxiety in women (22.38 ± 7.69 vs. 15.82 ± 7.18). Conclusions: This study demonstrates different levels of anxiety in terms of gender suffered by nursing students in high-pressure environments, such as a CPR situation
Damage in a large systemic lupus erythematosus cohort from the Spanish Society of Rheumatology Lupus Registry (RELESSER) with emphasis on the cardiovascular system: a longitudinal analysis
Objective To assess organ damage, with emphasis on the cardiovascular system, over the different stages of the disease in a large SLE cohort.Methods Multicentre, longitudinal study of a cohort of 4219 patients with SLE enrolled in the Spanish Society of Rheumatology Lupus Registry. Organ damage was ascertained using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). We longitudinally analysed SDI (globally and for each domain) over time only in the 1274 patients whose dates of damage events had been recorded.Results During the first year after diagnosis of SLE, 20% of the 1274 patients presented with new damage manifestations. At years 2 and 3, new damage was recorded in 11% and 9% of patients. The annual percentage of patients with new damage after year 5 decreased to 5%. In the first year with the disease, most damage was accumulated in the musculoskeletal, neuropsychiatric and renal systems; in later stages, most damage was in the musculoskeletal, ocular and cardiovascular systems. Considering 'cerebrovascular accident' and 'claudication for 6 months' as cardiovascular items, the cardiovascular system was the second most affected system during the early stages of SLE, with 19% of the patients who presented with damage affected at first year after diagnosis. During the late stages, 20-25% of the patients presenting with new damage did so in this modified cardiovascular domain of the SDI.Conclusions New damage occurs mainly during the first year following diagnosis of SLE. Cardiovascular damage is relevant in both the early and the late stages of the disease. Strategies to prevent cardiovascular damage should be implemented early after diagnosis of SLE
Political leaders' identity leadership and civic citizenship behavior:The mediating role of trust in fellow citizens and the moderating role of economic inequality
Identity leadership captures leaders efforts to create and promote a sense of shared group membership (i.e., a sense of “we” and of “us”) among followers. The present research report tests this claim by drawing on data from 26 countries that are part of the Global Identity Leadership Development (GILD) project to examine the relationship between political leaders' identity leadership and civic citizenship behavior (N = 6787). It also examines the contributions of trust and economic inequality to this relationship. Political leaders' identity leadership (PLIL) was positively associated with respondents' people-oriented civic citizenship behaviors (CCB-P) in 20 of 26 countries and civic citizenship behaviors aimed at one's country (CCB-C) in 23 of 26 countries. Mediational analyses also confirmed the indirect effects of PLIL via trust in fellow citizens on both CCB-P (in 25 out of 26 countries) and CCB-C (in all 26 countries). Economic inequality moderated these effects such that the main and indirect effects of trust in one's fellow citizens on CCB-C were stronger in countries with higher economic inequality. This interaction effect was not observed for CCB-P. The study highlights the importance of identity leadership and trust in fellow citizens in promoting civic citizenship behavior, especially in the context of economic inequality.</p
Political leaders' identity leadership and civic citizenship behavior:The mediating role of trust in fellow citizens and the moderating role of economic inequality
Identity leadership captures leaders efforts to create and promote a sense of shared group membership (i.e., a sense of “we” and of “us”) among followers. The present research report tests this claim by drawing on data from 26 countries that are part of the Global Identity Leadership Development (GILD) project to examine the relationship between political leaders' identity leadership and civic citizenship behavior (N = 6787). It also examines the contributions of trust and economic inequality to this relationship. Political leaders' identity leadership (PLIL) was positively associated with respondents' people-oriented civic citizenship behaviors (CCB-P) in 20 of 26 countries and civic citizenship behaviors aimed at one's country (CCB-C) in 23 of 26 countries. Mediational analyses also confirmed the indirect effects of PLIL via trust in fellow citizens on both CCB-P (in 25 out of 26 countries) and CCB-C (in all 26 countries). Economic inequality moderated these effects such that the main and indirect effects of trust in one's fellow citizens on CCB-C were stronger in countries with higher economic inequality. This interaction effect was not observed for CCB-P. The study highlights the importance of identity leadership and trust in fellow citizens in promoting civic citizenship behavior, especially in the context of economic inequality.</p
Hydroxychloroquine is associated with a lower risk of polyautoimmunity: data from the RELESSER Registry
Objectives. This article estimates the frequency of polyautoimmunity and associated factors in a large retrospective cohort of patients with SLE. Methods. RELESSER (Spanish Society of Rheumatology Lupus Registry) is a nationwide multicentre, hospital-based registry of SLE patients. This is a cross-sectional study. The main variable was polyautoimmunity, which was defined as the co-occurrence of SLE and another autoimmune disease, such as autoimmune thyroiditis, RA, scleroderma, inflammatory myopathy and MCTD. We also recorded the presence of multiple autoimmune syndrome, secondary SS, secondary APS and a family history of autoimmune disease. Multiple logistic regression analysis was performed to investigate possible risk factors for polyautoimmunity. Results. Of the 3679 patients who fulfilled the criteria for SLE, 502 (13.6%) had polyautoimmunity. The most frequent types were autoimmune thyroiditis (7.9%), other systemic autoimmune diseases (6.2%), secondary SS (14.1%) and secondary APS (13.7%). Multiple autoimmune syndrome accounted for 10.2% of all cases of polyautoimmunity. A family history was recorded in 11.8%. According to the multivariate analysis, the factors associated with polyautoimmunity were female sex [odds ratio (95% CI), 1.72 (1.07, 2.72)], RP [1.63 (1.29, 2.05)], interstitial lung disease [3.35 (1.84, 6.01)], Jaccoud arthropathy [1.92 (1.40, 2.63)], anti-Ro/SSA and/or anti-La/SSB autoantibodies [2.03 (1.55, 2.67)], anti-RNP antibodies [1.48 (1.16, 1.90)], MTX [1.67 (1.26, 2.18)] and antimalarial drugs [0.50 (0.38, 0.67)]. Conclusion. Patients with SLE frequently present polyautoimmunity. We observed clinical and analytical characteristics associated with polyautoimmunity. Our finding that antimalarial drugs protected against polyautoimmunity should be verified in future studies
Role of MUC1 rs4072037 polymorphism and serum KL-6 levels in patients with antisynthetase syndrome
Mucin 1/Krebs von den Lungen-6 (KL-6) is proposed as a serum biomarker of several interstitial lung diseases (ILDs), including connective tissue disorders associated with ILD. However, it has not been studied in a large cohort of Caucasian antisynthetase syndrome (ASSD) patients. Consequently, we assessed the role of MUC1 rs4072037 and serum KL-6 levels as a potential biomarker of ASSD susceptibility and for the differential diagnosis between patients with ILD associated with ASSD (ASSD-ILD +) and idiopathic pulmonary fibrosis (IPF). 168 ASSD patients (149 ASSD-ILD +), 174 IPF patients and 523 healthy controls were genotyped for MUC1 rs4072037 T > C. Serum KL-6 levels were determined in a subgroup of individuals. A significant increase of MUC1 rs4072037 CC genotype and C allele frequencies was observed in ASSD patients compared to healthy controls. Likewise, MUC1 rs4072037 TC and CC genotypes and C allele frequencies were significantly different between ASSD-ILD+ and IPF patients. Additionally, serum KL-6 levels were significantly higher in ASSD patients compared to healthy controls. Nevertheless, no differences in serum KL-6 levels were found between ASSD-ILD+ and IPF patients. Our results suggest that the presence of MUC1 rs4072037 C allele increases the risk of ASSD and it could be a useful genetic biomarker for the differential diagnosis between ASSD-ILD+ and IPF patients