Bipolarity in the querying of temporal databases

A database represents part of reality by containing data representing properties of real objects or concepts. To many real-world concepts or objects, time is an essential aspect and thus it should often be (implicitly) represented by databases, making these temporal databases. However, like other data, the time-related data in such databases may also contain imperfections such as uncertainties. One of the main purposes of a database is to allow the retrieval of information or knowledge deduced from its data, which is often done by querying the database. Because users may have both positive and negative preferences, they may want to query a database in a bipolar way. Moreover, their demands may have some temporal aspects. In this paper, a novel technique is presented, to query a valid-time relation containing uncertain valid-time data in a heterogeneously bipolar way, allowing every elementary query constraint a specific temporal constraint

A Relational Model for the Possibilistic Valid-time Approach

In real world, it is very common that some objects or concepts have properties with a time-variant or timerelated nature. Modelling this kind of objects or concepts in a (relational) database schema is possible, but time-variant and time-related attributes have an impact on the consistency of the entire database and must be appropriately managed. Therefore, temporal database models have been proposed to deal with this problem in the literature. Time can be affected by imprecision, vagueness and / or uncertainty, since existing time measuring devices are inherently imperfect. Additionally, human beings manage time using temporal indications and temporal notions, which may also be imprecise. However, the imperfection in human-used temporal indications is supported by human interpretation, whereas information systems need appropriate support in order to accomplish this task. Several proposals for dealing with such imperfections when modelling temporal data exist. Some of these proposals transform the temporal data into a compact representation but there is not a formal model for managing and handling uncertainty regarding temporal information. In this work we present a novel model to deal with imprecision in valid-time databases together with the definition and implementation of the data manipulation language, DML.Junta de Andalucia P07-TIC-03175 BES-2009-013805 TIN2008-0206

Aspects of dealing with imperfect data in temporal databases

In reality, some objects or concepts have properties with a time-variant or time-related nature. Modelling these kinds of objects or concepts in a (relational) database schema is possible, but time-variant and time-related attributes have an impact on the consistency of the entire database. Therefore, temporal database models have been proposed to deal with this. Time itself can be at the source of imprecision, vagueness and uncertainty, since existing time measuring devices are inherently imperfect. Accordingly, human beings manage time using temporal indications and temporal notions, which may contain imprecision, vagueness and uncertainty. However, the imperfection in human-used temporal indications is supported by human interpretation, whereas information systems need extraordinary support for this. Several proposals for dealing with such imperfections when modelling temporal aspects exist. Some of these proposals consider the basis of the system to be the conversion of the specificity of temporal notions between used temporal expressions. Other proposals consider the temporal indications in the used temporal expressions to be the source of imperfection. In this chapter, an overview is given, concerning the basic concepts and issues related to the modelling of time as such or in (relational) database models and the imperfections that may arise during or as a result of this modelling. Next to this, a novel and currently researched technique for handling some of these imperfections is presented

Life satisfaction: A comparative study between informal and formal workers

The life satisfaction of workers is measured by objective and subjective indicators, the latter not always considered by the governments of the countries. The objectives of this research were to analyze the relationship between the perception of having money, free time, health and a peaceful old age with the life satisfaction of informal and formal workers; and to compare the perception of the aforementioned variables, according to the type of worker (informal and formal). The methodological approach was correlational-exploratory, with surveys of 200 workers. The variables correlated as expected for the total sample, that is, positively and significantly between money, free time, health and old age with life satisfaction. When correlations are made by type of workers, the results are different. Through the application of Student's t test, no significant differences were found between the two types of workers, as expected by the political and economic area of Chile, believing that a formal worker and with objective welfare conditions, could present greater satisfaction with life, even in one item of the scale, informal workers have a higher perception. These results contribute to the science of subjective wellbeing and reaffirm its postulates on this side of the world.Peer ReviewedPostprint (published version

Mental health in health care workers: Engagement, burnout and healthy organizational practices in times of COVID-19

The work routine of workers has been modified by the COVID-19 pandemic and may vary according to the management of their organizations. The objectives of this research were to analyze the relationship between the perception of healthy organizational practices and workers' engagement and burnout and to determine which healthy organizational practices have a greater relationship with the engagement and burnout of employees in times of COVID-19. The methodological approach was correlational-exploratory, with surveys of 162 workers in 4 health centers in Chile. The variables correlated as expected for the total sample, i.e., positively and significantly between healthy organizational practices and engagement and negatively and significantly with burnout. The main practices that are related to increased engagement are career development, information, and skill development; and burnout is reconciliation, well-being, and communication. This research adds to the fundamentals that the mental health of workers is related to the type of management carried out by organizations.Peer ReviewedPostprint (published version

Bipolar fuzzy querying of temporal databases

Temporal databases handle temporal aspects of the objects they describe with an eye to maintaining consistency regarding these temporal aspects. Several techniques have allowed these temporal aspects, along with the regular aspects of the objects, to be defined and queried in an imprecise way. In this paper, a new technique is proposed, which allows using both positive and negative -possibly imprecise- information in querying relational temporal databases. The technique is discussed and the issues which arise are dealt with in a consistent way

We need engaged workers! A structural equation modeling study from the positive organizational psychology in times of COVID-19 in Chile

The COVID-19 pandemic has substantially impacted mental health—workers at institutions are not exempt. In our research, from positive organizational psychology, specifically from the healthy and resilient organization (HERO) model, we analyzed the relationship between healthy organizational practices–engagement and workers’ burnout, and evaluated the mediation role of engagement between healthy organizational practices and worker burnout levels during the COVID-19 pandemic, through structural equation models of a cross-sectional survey-based study. We collected data from a sample of 594 Chilean workers. Our results of the correlations and structural equations demonstrate the relationship between PHOs with engagement (ß = 0.51; p < 0.001) and burnout (ß = -0.44; p < 0.001), in addition to the mediating effect of engagement between HOP with burnout (ß = -0.66; p < 0.001). In conclusion, our findings suggest that healthy organizational practices promoted worker engagement and decreased worker burnout during the COVID-19 pandemic, contributing to the postulates of the HERO model. In addition, we were able to visualize a similar scenario, which showed that burnout during a pandemic decreases when worker engagement mediates the relationship with HOP.Peer ReviewedPostprint (published version

Preparation and characterization of a supramolecular hydrogel made of phospholipids and oleic acid with a high water content

A hydrogel formed with phospholipids and fatty acids would be of great interest in the medical field due to the biological relevance that these molecules have in living organisms. However, the tendency of phospholipid mixtures to form vesicular or micellar aggregates at high water content hinders the formation of this type of hydrogel. In this study, a highly hydrated hydrogel (95% water) was formed with hydrogenated phosphatidylcholine and oleic acid. The preparation method involved a freeze-heating cycle of the aqueous lipid mixture, favouring the supramolecular aggregation of these molecules into a microscopic spongy morphology. Confocal fluorescence imaging showed that the microstructure of the hydrogel is made from the aggregation of giant multilamellar vesicles (5-20 μm diameter) while transmission electron microscopy revealed the existence of nanosized unilamellar vesicles (150 nm diameter) coexisting with lipid lamellae. Despite this type of aggregation, X-ray scattering experiments performed on the hydrogel show almost no correlation between lipid membranes. In terms of rheological properties, the material shows a prevalent elastic behaviour and low structural strength, a consequence of non-covalent interactions. With such properties and composition, this structured but easily deformable material might become a useful tool for biomedical applications

Un servei de dinamització sòcio-econòmica per a les comaques de muntanya: el cas de l'Alt Urgell

El despoblament de les comarques de muntanya repercuteix no sols en un desarrelament de les persones afectades, sinó també en l'equilibri territorial general, ja que augmenta la congestió de les zones urbanes. Al marge del Plans de muntanya, per potenciar i recuperar aquelles comarques, cal trobar activitats alternatives i complementàries de l'agricultura i la ramaderia tradicionals. A l'Alt Urgell s'està fent una primera experiència en aquest sentit