Nutrient inputs from human activities, such as agriculture and sewage discharge, influence algal blooms in water bodies. In Ecuador, the Daule River receives wastewater discharges. In addition, poor agricultural practices, including the unsuitable use of fertilisers in combination with soil erosion and surface runoff processes, increase the nutrient load to the river. Considering this, the objective of this study was to evaluate environmental and biological variables using statistical analysis to identify the parameters that influence algal blooms in the main stem of the Daule River. The methodology consisted of two phases: (i) data collection, including water sampling and laboratory work for the analysis of nutrients and phytoplankton, and (ii) statistical analysis, which includes univariate, bivariate, inferential and multivariate analysis (STATICO technique). The results showed that pH and dissolved oxygen were the main drivers of diatoms (Polymyxus coronalis and Aulacoseira granulate) and the charophyte Mougeotia sp. Similarly, ammonium-N was the main driver of the diatom Ulnaria ulna and the cyanobacteria Planktothrix cf. agardhii. The outcomes of this study identified the main environmental variables driving blooms of the five most abundant species, providing a basis for the development of ecological models in the context of land use and climate change.
Research on sustainable careers often overlooks professionals in under-represented regions. In dynamic labor markets, such as Latin America, there is limited evidence on how individuals build meaningful and healthy career paths over time. Guided by the sustainable careers model, this study addresses this gap by validating a Spanish version of the career sustainability scale and testing its predictive value in the Mexican context. Two studies were conducted, with cross-sectional survey data. Study 1 confirmed the scale's four-factor structure and solid psychometric properties, via EFA/CFA, internal consistency, and measurement invariance by gender, and showed concurrent associations with job autonomy, work engagement, and intention to quit. Study 2 tested a moderated mediation model. Psychological capital mediated the effects of career sustainability on life satisfaction, psychological health, and task performance. Social isolation reduced the indirect effect only for psychological capital. These findings support a view of sustainable careers shaped by personal resources and social contexts and extend this research in Spanish-speaking settings, offering practical implications for well-being and performance in emerging labor markets.
Fractional quantum dynamics provides a natural framework to describe nonlocal temporal behavior and memory effects in quantum systems. Building on this idea, we develop a fractional Green’s function formulation for the time-dependent Schrödinger equation based on the Caputo fractional derivative, which enables a systematic treatment of fractional-order quantum evolution. When applied to an extended two-level Rabi model, a paradigmatic setting for coherent quantum control, we find that even the static Hamiltonian term leads to non-trivial spin dynamics with damping features directly linked to fractional temporal nonlocality. Upon introduction of a periodic driving field, the fractional regime produces controllable damping and dephasing governed by the order of the fractionality, which could be observed through the Loschmidt echo and autocorrelation function, offering potential routes to probe fractional quantum dynamics experimentally. Our findings open pathways to explore memory-induced dynamical phenomena in other systems effectively described by two-level approximations, such as graphene-like materials and topological SSH chains, where non-integer-order evolution may reveal novel topological or relaxation regimes.
Blockchain technology has fundamentally transformed the landscape of secure and transparent transactions within decentralized networks. Combined with advanced cryptographic techniques, Blockchain offers significant improvements in security and reliability, addressing critical concerns about data integrity, confidentiality, and trust. This review delves into recent advancements in Cryptography and Blockchain, focusing on their application to secure communications and transactions in Data Networks. Through a state-of-the-art analysis, this paper examines key cryptographic methods, including encryption, digital signatures, and consensus algorithms, strengthening Security Data Networks. In conclusion, this study underscores the potential of Blockchain Technology reshaping data security and transparency across various sectors, and also paving the way for enhanced trust and operational efficiency in digital ecosystems.
This article examines the existence of solutions to a Volterra-type integral equation in the space of functions of bounded-variation. Conditions on the given functions are established to guarantee the existence of such solutions. Furthermore, it is shown that any two solutions are equal almost everywhere. The possibility of extending solutions to larger intervals is also explored.
