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En este artículo se demuestra que en un modelo simple de determinación de la renta, cuando se tienen en cuenta funciones de consumo lineales, la tasa de variación del producto interior bruto (PIB) es igual al cociente entre el incremento de la inversión y la suma del consumo exógeno más la inversión inicial. Esto significa que la pendiente de la función de consumo no influye en la tasa de variación del PIB y que lo relevante para esa tasa de variación es el consumo exógeno y la inversión inicial. || In this paper, we prove that in a simple model of income determination, when taking into account linear functions, the change rate for the gross domestic product (GDP) is equal to the quotient of the increase in investment and the sum of exogenous consumption plus the initial investment. This means that the slope of the consumption function does not influence the change rate for the GDP and what matters for this variation rate is the exogenous consumption and the initial investment.

Background: Amidst current misinformation, media literacy is an essential competency for nursing professionals. This study aimed to analyze the level of media health literacy among Spanish undergraduate nursing students, stratifying the results by gender, region, and other associated factors. Methods: A cross-sectional study was conducted at five Spanish universities (N = 416) using the Spanish version of the Media Health Literacy (MeHLit-SV) Questionnaire. Results: Students presented an average media health literacy score of 48.73 points. The media health literacy level was significantly higher among students from universities in the central and northeastern regions of Spain (ANOVA Test, p = 0.0002), those who had previously studied in a city (ANOVA Test, p = 0.001), those who combined their studies with employment (ANOVA Test, p = 0.001), and those residing in communities with fewer than 500 inhabitants (ANOVA Test, p = 0.001). No differences were found based on gender. Conclusions: The media health literacy level of the students was deficient and varied according to socio-economic and socio-educational factors. Understanding the literacy level of future nurses and promoting the inclusion of this competency in their education will enable them to become leaders in improving the population's health self-care. [ABSTRACT FROM AUTHOR]

Background: Chemsex has been defined as the deliberate use of drugs for prolonged sexual intercourse between gay and bisexual men and other men who have sex with men (MSM). Drugs associated with chemsex can trigger mental health problems such as anxiety, depression, risk of psychosis and suicidal ideation, social isolation, stigmatization, and even loss of impulse control and lack of coping strategies. Currently, the increase in illicit drugs in a sexual context is considered an outbreak of a public health emergency. Objective: The aim of this study is the construction and validation of the Chem-Sex Inventory (CSI), a new scale to assess the mental health risk of chemsex behaviors. Methods: A cross-sectional design was conducted to study 563 participants. Data were collected through an online questionnaire between January and April 2023, and the construct validity of the CSI was assessed through exploratory and confirmatory factor analysis. Results: The sample was, on average, 36 years old (SD: ±9.2). The majority of gender identity was cisgender (97.7%). A factor structure was found that can be summarized in four dimensions: emotional instability, risk of psychosis, altered body perception, and risk of suicide. The confirmatory factor analysis (CFA) presents adequate reliability values, with a Cronbach's alpha above 0.87 for all dimensions and a McDonald's omega above 0.88 with a good fit of the 42 items. Conclusions: Our study has shown that the Chem-Sex Inventory (CSI) scale has factorial validity and could be used in clinical practice and research to measure the behavioral contribution of the chemsex phenomenon in MSM. [ABSTRACT FROM AUTHOR]

The present investigation studies the use of three natural precursors of volcanic origin (pozzolana, ignimbrite and pumice) in the synthesis of low-cost and environmentally friendly zeolites. The developed zeolites were evaluated as sustainable catalysts for the catalytic pyrolysis process in the chemical recycling of polypropylene. A zeolite was synthesized from each precursor. The hydrothermal treatment was performed with NaOH (3M) at 160 °C for 72 h and NH4Cl (1M) was added to convert it into proton form. The synthesized zeolites were characterized by FTIR, XRD, SEM and BET. The evaluation of the catalytic ability of the obtained zeolites was carried out with polypropylene mixed with a 4, 6 and 8 wt.% catalyst in a ceramic crucible. Pyrolysis was always carried out at 450 °C and for 30 min in a tubular furnace with a continuous flow rate of 250 L·min−1 of gaseous nitrogen. The gases generated were captured in the cooling system. The characterized zeolites show a resemblance to the ZSM-5 commercial zeolite, especially for the ignimbrite and pozzolan zeolites. Likewise, in pyrolysis, liquid products, gases and waxes were obtained. As the amount of catalyst was increased (from 4 to 8%), the yield of the desired liquid–gas products was also increased. The synthesized zeolites showed similar pyrolytic characteristics to ZSM-5, although they did not reach the same pyrolytic efficiency. Zeolites improved the pyrolysis products, especially at 8 wt.%, when compared to thermal pyrolysis. This study highlights the potential of the developed zeolite catalysts to efficiently convert PP into valuable light olefins, advancing sustainable polyolefin recycling technologies. [ABSTRACT FROM AUTHOR]

Alkali-activated slag (AAS) materials are one of the most promising alternatives to ordinary Portland cement (PC), as the AAS curing process does not require thermal activation, unlike the activation of other wastes. In addition, AAS exhibit lower porosity than PC, but experience shrinkage problems that can negatively affect their in-service implementation and durability. Shrinkage can directly impact the mechanical properties of AAS as well as the corrosion protection of steel reinforced structures in environments with chlorides, and be a factor affecting durability. The length change during the curing of these mortars can generate high stresses that are released through the formation of microcracks or cracks in their structure. Cracks can act as preferential diffusion paths for aggressive chloride ions and favor the corrosion of the reinforcement. The aim of the present work is to study the reduction in shrinkage that can be achieved for AAS using five different activators: NaOH 4 M, waterglass (WG) with two different SiO2/Na2O molar ratios (MR) and Na2CO3 solution without and with 10% MgO additions. The results reveal that AAS activated with Na2CO3 shows very reduced microcracking. The addition of expansive MgO completely eliminates microcracking but makes the mortar more porous. In the latter case, the pits become much smaller and potentially less dangerous than the ones appearing in the other studied mortars. Alkali-activated slag mortars manufactured in five different ways (Na2O fixed ratio) are tested. Shrinkage behavior of mortars is related to the corrosion of the embedded steel. Cyclic immersions in NaCl favour chloride diffusion and precipitation in reinforced mortars. Pit morphologies are related to Cl- transport through cracks, microcracks or/and porosity. WG (0.8 SiO2/Na2O MR) or Na2CO3 are promising options to activate slag for carbon steel-reinforced mortars. [ABSTRACT FROM AUTHOR]

Summary: This article presents a model predictive control for dynamic positioning (DP) of floating caisson at different draughts. This article focuses on the maneuvres related to the control of the spatial situation of the caisson in connexion with the final caisson reference point and the process of descending to the seabed desired location. Different models of the caisson in order to perform realistic simulations and to test the robustness of the controller are considered. A gain scheduling model predictive control (GSMPC) has been implemented, with parameter switch among four model predictive control (MPC) controllers. In this way, a specific MPC for the dynamics of each draught will be used in each caisson model corresponding to a draught. Furthermore, a Kalman filter has been implemented to remove the disturbances. Finally, in the simulations results it is compared the performance of the proposed controller with a clasic one and also it is checked how the proposed controller is able to position the system in all draughts with stability and accurate dynamic control of the system. [ABSTRACT FROM AUTHOR]

Nowadays, many maritime structures require precise dynamic positioning (DP) of the constructive elements that compose them. In addition, the use of preconstructed elements that are later moved to the final location has become widespread. These operations have not been automated with the risks involved in carrying out the complex operations required. To minimize these operational risks and to perform a correct DP of floating structures, a new approach based on the L1 adaptive control technique is proposed. As an example of application, a proposed L1 adaptive controller was implemented in the dynamic positioning of a floating caisson. Several simulations of the system with wave disturbances were carried out, and the results were compared with those obtained by applying other classical and advanced control techniques, such as linear quadratic Gaussian control (LQG) and model predictive control (MPC). It was concluded that the proposed L1 adaptive controller performs correct dynamic positioning and reduces the tension generated on the lines concerning the other advanced control techniques with which it was compared. This reduction in line tension leads to an important improvement due to the possibility of reducing the size of the actuators or reducing their number, with the important economic and safety repercussions that these actions entail. [ABSTRACT FROM AUTHOR]

Both education and religion are connected with the sense of identity. In the present global world, educators have a real challenge to be able to manage identity and diversity, the local and the global, especially in the "cultural" subjects, fields where to learn to think is also to learn to construct an opinion (especially in order to define "otherness", to learn to live within differences). Religious education could be, from a methodological point of view, a laboratory for an education for peace. However, we need to think beyond the dichotomy of confessional/non-confessional. A four-fold model of religious education is proposed: theocratic, national religion, secular and multi-religious. The first three are problematic for education in diversity and peace; the multi-religious option provides the best opportunity, but only if religious education is defined in a non religiocentric way, able to combine the sensibilities and points of view of different particular cultural identities, but also respecting a global, human common identity.