Depression and cognition: new insights from the Lorenz curve and the Gini index

This ex post facto prospective study reports the use of statistical techniques known as the Lorenz curve and Gini index to analyze the content of depressive cognitions as a function of attributional negative style (i.e., internal, global and stable causal attributions for failure or negative events, as proposed by the learned helplessness model) and negative cognitive triad (i.e., a negative view of oneself, ones future and ones world, according to Beck’s cognitive model of depression). These statistical techniques revealed that attributional style was poorly related with depression level, whereas the negative cognitive triad showed a close relationship and provided a more accurate description of the depressive cognitive pattern. We also document how the Lorenz curve and Gini index can be used to assess the predictive capacity of different instruments or the strength of the relationship between different variables and psychological disorders, and to evaluate different models proposed to explain these disorders. This pioneering study reveals the potential usefulness in Psychology of these statistical techniques, mainly used in Economical sciences, for analyzing the validity of different factors and possible predictors of specific psychological disorders, or to enhance existing instruments, as our present study with depression shows.La principal aportación del actual estudio prospectivo ex post facto es el uso de técnicas estadísticas conocidas como la Curva de Lorenz o el Índice de Gini, para analizar el contenido de las cogniciones depresivas, en función del estilo atribucional (i.e., atribuciones internas, estables y globales para las causas del fracaso o de sucesos negativos, como propone el modelo de la indefensión aprendida) y la triada cognitiva negativa (i.e., una visión negativa de sí mismo, del mundo y del futuro, acorde al modelo cognitivo de Beck de la depresión). Tanto las curvas de Lorenz, como los índices de Gini, revelaron que, mientras el estilo atribucional estaba poco relacionado con el nivel de depresión, la triada cognitiva negativa mostraba una alta relación, lo que sugiere que esta última constituye una mejor descripción del contenido cognitivo de los pensamientos depresivos. Al mismo tiempo, este estudio documenta como ambas técnicas, Índice de Gini y Curva de Lorenz, pueden usarse para evaluar tanto la capacidad predictiva de diferentes instrumentos o técnicas de medida psicológicas, como la validez de las variables propuestas por los modelos teóricos que pretenden explicar trastornos psicológicos concretos. Este estudio pionero revela por tanto, la utilidad potencial de estas técnicas estadísticas en Psicología tanto para analizar los factores o predictores de trastornos psicológicos específicos, como para potenciar los instrumentos de medida existentes, como se ha mostrado en este trabajo para la depresión.O presente estudo prospectivo ex post facto relata o uso de técnicas estatísticas conhecidas como a Curva de Lorenz ou o Índice de Gini, para analisar o conteúdo das cognições depressivas, em função do estilo atribucional (i.e., atribuições internas, estáveis e globais para as causas do fracasso ou de acontecimentos negativos, como propõe o modelo do desânimo aprendido) e a tríade cognitiva (i.e., uma visão negativa de si mesmo, do mundo e do futuro, de acordo com o modelo cognitivo de Beck da depressão). Tanto as curvas de Lorenz, como os índices de Gini, revelaram que, apesar de o estilo atribucional estar pouco relacionado com o nível de depressão, a tríade cognitiva mostrava uma alta relação, o que sugere que esta última constitui uma melhor descrição do conteúdo cognitivo dos pensamentos depressivos. Ao mesmo tempo, este estudo documenta como ambas as técnicas, Índice de Gini e Curva de Lorenz, se podem usar para avaliar tanto a capacidade preditiva de diferentes instrumentos ou técnicas de medida psicológicas, como a validade das variáveis propostas pelos modelos teóricos que pretendem explicar perturbações psicológicas concretas. Este estudo pioneiro revela portanto, a utilidade potencial destas técnicas estatísticas em Psicologia tanto para analisar os factores ou preditores de perturbações psicológicas específicas, como para potenciar os instrumentos de medida existentes, como se mostrou neste trabalho para a depressão.This research was supported by a DGICYT grant to A. Maldonado (PB 98-1352) and (MTN2004-03672) to R. Pérez-Ocón

MoMA Algorithm: A Bottom-Up Modeling Procedure for a Modular System under Environmental Conditions

The functioning of complex systems relies on subsystems (modules) that in turn are composed of multiple units. In this paper, we focus on modular systems that might fail due to wear on their units or environmental conditions (shocks). The lifetimes of the units follow a phase-type distribution, while shocks follow a Markovian Arrival Process. The use of Matrix-Analytic methods and a bottom-up approach for constructing the system generator is proposed. The use of modular structures, as well as its implementation by the Modular Matrix-Analytic (MoMA) algorithm, make our methodology flexible in adapting to physical changes in the system, e.g., incorporation of new modules into the current model. After the model for the system is built, the modules are seen as a ‘black box’, i.e., only the contribution of the module as a whole to system performance is considered. However, if required, our method is able to keep track of the events within the module, making it possible to identify the state of individual units. Compact expressions for different reliability measures are obtained with the proposed description, optimal maintenance strategies based on critical operative states are suggested, and a numerical application based on a k-out-of-n structure is developed.Spanish Ministry of Science and Innovation-State Research Agency PID2020-120217RB-I00 PID2021-123737NB-I00Junta de Andalucia B-FQM-284-UGR20 CEX2020-001105-/AEI/10.13039/50110001103

Association of Urinary Levels of Bisphenols A, F, and S with Endometriosis Risk: Preliminary Results of the End EA Study

Aim: The aim of this study was to explore associations of urinary concentrations of bisphenols A (BPA), S (BPS), and F (BPF) and of thiobarbituric acid reactive substances (TBARS) with the risk of endometriosis in women of childbearing age. Results: After adjustment for urinary creatinine, age, BMI, parity, and residence, endometriosis risk was increased with each 1 log unit of BPA [OR 1.5; 95%CI 1.0–2.3] and Sbisphenols [OR 1.5; 95%CI 0.9–2.3] but was not associated with the presence of BPS and BPF. Classification of the women by tertiles of exposure revealed statistically significant associations between endometriosis risk and the second tertile of exposure to BPA [OR 3.7; 95%CI 1.3–10.3] and Sbisphenols [OR 5.4; 95%CI 1.9–15.6]. In addition, TBARS concentrations showed a close-to-significant relationship with increased endometriosis risk [OR 1.6; 95%CI 1.0–2.8], and classification by TBARS concentration tertile revealed that the association between endometriosis risk and concentrations of BPA [OR 2.0; 95%CI 1.0–4.1] and Sbisphenols [OR 2.2; 95%CI 1.0–4.6] was only statistically significant for women in the highest TBARS tertile (>4.23 uM). Conclusion: Exposure to bisphenols may increase the risk of endometriosis, and oxidative stress may play a crucial role in this association. Further studies are warranted to verify these findings.Instituto de Salud Carlos III: PI17/01743; Instituto de Salud Carlos III: PI16/01820; Instituto de Salud Carlos III: PI16/01812; Instituto de Salud Carlos III: PI16/01858; Instituto de Salud Carlos III: PI17/01526; Instituto de Salud Carlos III: IFI18/00052; Instituto de Salud Carlos III: FI17/00316; Instituto de Salud Carlos III: INT18/00060; European Commission: H2020-EJP-HBM4EU

Regular insulin added to total parenteral nutrition vs subcutaneous glargine in non-critically ill diabetic inpatients, a multicenter randomized clinical trial: INSUPAR trial

Background: There is no established insulin regimen in T2DM patients receiving parenteral nutrition. Aims: To compare the effectiveness (metabolic control) and safety of two insulin regimens in patients with diabetes receiving TPN. Design: Prospective, open-label, multicenter, clinical trial on adult inpatients with type 2 diabetes on a non-critical setting with indication for TPN. Patients were randomized on one of these two regimens: 100% of RI on TPN or 50% of Regular insulin added to TPN bag and 50% subcutaneous Gl. Data were analyzed according to intention-to-treat principle. Results: 81 patients were on RI and 80 on GI. No differences were observed in neither average total daily dose of insulin, programmed or correction, nor in capillary mean blood glucose during TPN infusion (165.3 +/- 35.4 in RI vs 172.5 +/- 43.6 mg/dL in GI; p = 0.25). Mean capillary glucose was significantly lower in the GI group within two days after TPN interruption (160.3 +/- 45.1 in RI vs 141.7 +/- 43.8 mg/dL in GI; p = 0.024). The percentage of capillary glucose above 180 mg/dL was similar in both groups. The rate of capillary glucose <= 70 mg/dL, the number of hypoglycemic episodes per 100 days of TPN, and the percentage of patients with non-severe hypoglycemia were significantly higher on GI group. No severe hypoglycemia was detected. No differences were observed in length of stay, infectious complications, or hospital mortality. Conclusion: Effectiveness of both regimens was similar. GI group achieved better metabolic control after TPN interruption but non-severe hypoglycemia rate was higher in the GI group. (C) 2019 The Author(s). Published by Elsevier Ltd

Fish Oil Enriched Intravenous Lipid Emulsions Reduce Triglyceride Levels in Non-Critically Ill Patients with TPN and Type 2 Diabetes. A Post-Hoc Analysis of the INSUPAR Study

There are no studies that have specifically assessed the role of intravenous lipid emulsions (ILE) enriched with fish oil in people with diabetes receiving total parenteral nutrition (TPN). The objective of this study was to assess the metabolic control (glycemic and lipid) and in-hospital complications that occurred in non-critically ill inpatients with TPN and type 2 diabetes with regard to the use of fish oil emulsions compared with other ILEs. We performed a post-hoc analysis of the Insulin in Parenteral Nutrition (INSUPAR) trial that included patients who started with TPN for any cause and that would predictably continue with TPN for at least five days. The study included 161 patients who started with TPN for any cause. There were 80 patients (49.7%) on fish oil enriched ILEs and 81 patients (50.3%) on other ILEs. We found significant decreases in triglyceride levels in the fish oil group compared to the other patients. We did not find any differences in glucose metabolic control: mean capillary glucose, glycemic variability, and insulin dose, except in the number of mild hypoglycemic events that was significantly higher in the fish oil group. We did not observe any differences in other metabolic, liver or infectious complications, in-hospital length of stay or mortality

The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients

Background: Mortality due to COVID-19 is high, especially in patients requiring mechanical ventilation. The purpose of the study is to investigate associations between mortality and variables measured during the first three days of mechanical ventilation in patients with COVID-19 intubated at ICU admission. Methods: Multicenter, observational, cohort study includes consecutive patients with COVID-19 admitted to 44 Spanish ICUs between February 25 and July 31, 2020, who required intubation at ICU admission and mechanical ventilation for more than three days. We collected demographic and clinical data prior to admission; information about clinical evolution at days 1 and 3 of mechanical ventilation; and outcomes. Results: Of the 2,095 patients with COVID-19 admitted to the ICU, 1,118 (53.3%) were intubated at day 1 and remained under mechanical ventilation at day three. From days 1 to 3, PaO2/FiO2 increased from 115.6 [80.0-171.2] to 180.0 [135.4-227.9] mmHg and the ventilatory ratio from 1.73 [1.33-2.25] to 1.96 [1.61-2.40]. In-hospital mortality was 38.7%. A higher increase between ICU admission and day 3 in the ventilatory ratio (OR 1.04 [CI 1.01-1.07], p = 0.030) and creatinine levels (OR 1.05 [CI 1.01-1.09], p = 0.005) and a lower increase in platelet counts (OR 0.96 [CI 0.93-1.00], p = 0.037) were independently associated with a higher risk of death. No association between mortality and the PaO2/FiO2 variation was observed (OR 0.99 [CI 0.95 to 1.02], p = 0.47). Conclusions: Higher ventilatory ratio and its increase at day 3 is associated with mortality in patients with COVID-19 receiving mechanical ventilation at ICU admission. No association was found in the PaO2/FiO2 variation

Analysis of k-Out-of-N-Systems with Different Units under Simultaneous Failures: A Matrix-Analytic Approach

An N-system with different units submitted to shock and wear is studied. The shocks cause damage and, eventually, simultaneous failures of several units. The units can also fail due to internal failures. At random times, the system is inspected, and the down units are simultaneously replaced by identical ones. The arrival of shocks is governed by a Markovian arrival process. The operational times and the interarrival times between inspections follow phase-type distributions. The generator of the multidimensional Markov process modeling the system is constructed. This is performed introducing indicator functions for the different transition rates among the units using the algorithm of Kronecker. This is a general Markov process that can be applied for modeling different reliability systems depending on the structure of the units and how the systems operate. The general model is applied to the study of k-out-of-N systems, calculating the main performance measures. A practical example is presented showing the approximation of the model to a system with units following different Weibull distributions

Optimizing Costs in a Reliability System under Markovian Arrival of Failures and Reposition by K-Policy Inspection

This paper presents an N warm standby system under shocks and inspections governed by Markovian arrival processes. The inspections detect the number of down units, and their replacement is carried out if there are a minimum K of failed units. This is a policy of the type (K, N) used in inventory theory. The study is performed via the up and down periods of the system (cycle); the distribution of these random times and the expected costs for each period comprising the cycle are determined on the basis of individual costs due to maintenance actions (per inspection and replacement of every unit) and others due to operation or inactivity of the system, per time unit. Intermediate addressed calculus are the distributions of the number of inspections by cycle and the expected cost involving every inspection, depending on the number of replaced units. The system is studied in transient and stationary regimes, and some reliability measures of interest and the cost rate are calculated. An optimization of these quantities is performed in terms of the number K in a numerical example. This general model extends to many others in the literature, and, by using the matrix-analytic method, compact and algorithmic expressions are achieved, facilitating its potential application

On first-passage times in increasing Markov processes

We obtain the sufficient conditions for an increasing Markov process to belong to the NBUC or DMRL reliability classes. This study extends the existing literature on IFR, IFRA, and NBUE classes.First-passage times Life distributions NBUC and DMRL processes

Two shock and wear systems under repair standing a finite number of shocks

A shock and wear system standing a finite number of shocks and subject to two types of repairs is considered. The failure of the system can be due to wear or to a fatal shock. Associated to these failures there are two repair types: normal and severe. Repairs are as good as new. The shocks arrive following a Markovian arrival process, and the lifetime of the system follows a continuous phase-type distribution. The repair times follow different continuous phase-type distributions, depending on the type of failure. Under these assumptions, two systems are studied, depending on the finite number of shocks that the system can stand before a fatal failure that can be random or fixed. In the first case, the number of shocks is governed by a discrete phase-type distribution. After a finite (random or fixed) number of non-fatal shocks the system is repaired (severe repair). The repair due to wear is a normal repair. For these systems, general Markov models are constructed and the following elements are studied: the stationary probability vector; the transient rate of occurrence of failures; the renewal process associated to the repairs, including the distribution of the period between replacements and the number of non-fatal shocks in this period. Special cases of the model with random number of shocks are presented. An application illustrating the numerical calculations is given. The systems are studied in such a way that several particular cases can be deduced from the general ones straightaway. We apply the matrix-analytic methods for studying these models showing their versatility.Shock and wear model Repair Replacement Markovian arrival process Phase-type distribution