Repositorio Digital Universidad Simón Bolívar
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Tejido adiposo epicárdico, adiponectina y leptina: Una fuente potencial de riesgo cardiovascular en Enfermedad renal crónica
No full textThe importance of cardiometabolic factors in the inception and progression of atherosclerotic
cardiovascular disease is increasingly being recognized. Beyond diabetes mellitus and metabolic
syndrome, other factors may be responsible in patients with chronic kidney disease (CKD) for the
high prevalence of cardiovascular disease, which is estimated to be 5- to 20-fold higher than in the
general population. Although undefined uremic toxins are often blamed for part of the increased
risk, visceral adipose tissue, and in particular epicardial adipose tissue (EAT), have been the focus of
intense research in the past two decades. In fact, several lines of evidence suggest their involvement
in atherosclerosis development and its complications. EAT may promote atherosclerosis through
paracrine and endocrine pathways exerted via the secretion of adipocytokines such as adiponectin
and leptin. In this article we review the current knowledge of the impact of EAT on cardiovascular
outcomes in the general population and in patients with CKD. Special reference will be made to
adiponectin and leptin as possible mediators of the increased cardiovascular risk linked with EAT
Forecasting electric load demand through advanced statistical techniques
No full textTraditional forecasting models have been widely used for decision-making in production, finance and energy. Such is the case of the ARIMA models, developed in the 1970s
by George Box and Gwilym Jenkins [1], which incorporate characteristics of the past models of the same series, according to their autocorrelation. This work compares advanced statistical methods for determining the demand for electricity in Colombia, including the SARIMA,
econometric and Bayesian methods
Internet of Things applied to Aquifer Monitoring Systems: A survey
No full textThe interaction between the oceanic and continental basins has been of general interest among the scientific community of multiple disciplines, from the physical perspective of how the interaction of fresh and salt waters mutually modulate their hydrodynamic behavior, and how this in turn determines the transport of sediments, nutrients and other tracers, in addition to inducing changes in the morphodynamics of the river and / or coastal-oceanic zone. Due to the importance of technology for the prevention of different environmental phenomena, this article aims to show the systematic review of the literature about different applications that allow software and hardware interaction to support decision making in the sense of aquifers
Conditions of human talent management that favor the development of dynamic capabilities
No full textSe estudia y analiza las condiciones de la gestión del talento humano que favorecen el desarrollo de
capacidades dinámicas de un grupo de directivos de empresas. Se planteó una investigación cuantitativa,
mediante la aplicación de una encuesta compuesta por catorce ítems medidos en una escala tipo Likert,
dirigida a setenta líderes ubicados en empresas de diferentes sectores de la economía en la ciudad de
Barranquilla, Colombia. Los resultados muestran que el espacio compartido de conocimiento y el estilo de
dirección de liderazgo que promueva la transformación y el cambio tienen un impacto positivo en el desarrollo
de capacidades dinámicas de los líderes, para adaptarse a las condiciones cambiantes de entornoThe conditions of human talent management that favor the development of dynamic capabilities of a group of
business executives are studied and analyzed. Quantitative research was proposed through the application of
a survey composed of fourteen items measured on a Likert scale, addressed to seventy leaders of companies
from different sectors of the economy, located in the city of Barranquilla, Colombia. The results show that the
shared knowledge space and a leadership style that promotes transformation and changes have positive
impact on the development of the dynamic capabilities of the leaders, to adapt themselves to the changing
corporate environmental conditions
Natural language explanation model for decision trees
No full textThis study describes a model of explanations in natural language for classification
decision trees. The explanations include global aspects of the classifier and local aspects of the
classification of a particular instance. The proposal is implemented in the ExpliClas open source
Web service [1], which in its current version operates on trees built with Weka and data sets with
numerical attributes. The feasibility of the proposal is illustrated with two example cases, where
the detailed explanation of the respective classification trees is shown
University-enterprise-state relationship. An analysis from higher education institutions of Barranquilla-Colombia, for the development of their innovation capacity
No full textSe analiza la relación universidad-empresa-estado, desde las instituciones de educación superior para el
desarrollo de capacidad de innovación en Barranquilla, Colombia. Se propuso una revisión de las actividades
que involucran relaciones con el sector externo realizadas por este tipo de instituciones. Se planteó una
investigación cualitativa apoyada en la revisión documental que resultó valiosa para contrastar los referentes
bibliográficos con las acciones realizadas por las instituciones. Los principales hallazgos destacan que acorde
al tipo de carácter académico, las universidades son quienes actualmente fortalecen sus procesos de
docencia como su misión tradicional, y paralelamente desarrollan actividades de investigación y extensión
que contribuyen al desarrollo del país. Como resultado final se encontró que, la triada universidad- empresaestado es la alianza adecuada para el desarrollo de innovaciones que respondan a las necesidades y
oportunidades del entorno.The university-business-state relationship, from the point of view of the innovation capacity of the higher
education institutions in Barranquilla, Colombia is analyzed. A review of the activities that involve relations with
the external sector made by this type of institutions was proposed. A qualitative research was carried on based
on the documentary review that was valuable to contrast the bibliographic references with the actions carried
out by the institutions. The main findings indicate that according to the type of academic character, Universities
are the institutions that strengthen their teaching processes as their traditional mission, and also develop
research and extension activities that contribute to the development of the country. As a final result, it was
found that the triad university-business-state is the appropriate alliance for the development of innovations that
respond to the needs and opportunities of the surroundings
Energy savings measures in compressed air systems
No full textCompressed air is one of the most widely used application energies in the industry, such as good transportability, safety, purity, cleanliness, storage capacity and ease of use. In many countries, compressed air systems account for approximately 10% of the industry’s total electricity consumption. Despite all its advantages, compressed air is expensive, only between 10% and 30% of the energy consumed reaches the point of final use. Energy is lost as heat, leaks, pressure drop, misuse, among others. Energy efficiency measures such as: reducing compressor pressure, lowering air inlet temperature, adequate storage capacity, recovering residual heat from the air compressor and reducing leakage, can produce energy savings between 20% and 60%, with an average return on investment lower than 2 years. This paper analyzes the main energy efficiency measures that can be applied in the CASs, the potential energy savings, implementation costs and return rate of each of them are being calculated giving a necessary tool for companies in their objectives to reduce greenhouse gas emissions and energy consumption
Data mining and neural networks to determine the financial market prediction
No full textPredicting stock market movements has been a complex task for years by gaining the increasing interest of researchers and investors present all around the world. These have tried to get ahead of the way in order to know the levels of return and thus reduce the risk they face in investments [1]. Capital markets are areas of fundamental importance for the development of economies and their good management that favors the transition from savings to investment through the purchase and sale of shares [2]. These actions are so important that they are influenced by economic, social, political, and cultural variables. Therefore, it is reasonable to consider the value of an action in an instant not as a deterministic variable but as a random variable, considering its temporal trajectory as a stochastic process
Measuring the financial performance of MSMEs through artificial neural networks
No full textGiven the importance of micro, small and medium-sized enterprises (MSMEs) in Colombia, both in terms of the number of enterprises and the generation of employment, it is important to know their nature, as well as the main determinants of their financial performance. In this sense, this paper aims to provide relevant information for the formulation of strategies, programs and public policies that promote practices within companies and thus improve the performance of this segment of organizations
Interaction with soil bacteria affects the growth and amino acid content of piriformospora indica
No full textExploration of the e ect of soil bacteria on growth and metabolism of beneficial root
endophytic fungi is relevant to promote favorable associations between microorganisms of the plant
rhizosphere. Hence, the interaction between the plant-growth-promoting fungus Piriformospora indica
and di erent soil bacteria was investigated. The parameters studied were fungal growth and its
amino acid composition during the interaction. Fungus and bacteria were confronted in dual
cultures in Petri dishes, either through agar or separated by a Perspex wall that only allowed the
bacterial volatiles to be e ective. Fungal growth was stimulated by Azotobacter chroococcum, whereas
Streptomyces anulatus AcH 1003 inhibited it and Streptomyces sp. Nov AcH 505 had no e ect. To analyze
amino acid concentration data, targeted metabolomics was implemented under supervised analysis
according to fungal-bacteria interaction and time. Orthogonal partial least squares-discriminant
analysis (OPLS-DA) model clearly discriminated P. indica–A. chroococcum and P. indica–S. anulatus
interactions, according to the respective score plot in comparison to the control. The most observable
responses were in the glutamine and alanine size groups: While Streptomyces AcH 1003 increased the
amount of glutamine, A. chroococcum decreased it. The fungal growth and the increase of alanine
content might be associated with the assimilation of nitrogen in the presence of glucose as a carbon
source. The N-fixing bacterium A. chroococcum should stimulate fungal amino acid metabolism via
glutamine synthetase-glutamate synthase (GS-GOGAT). The data pointed to a stimulated glycolytic
activity in the fungus observed by the accumulation of alanine, possibly via alanine aminotransferase.
The responses toward the growth-inhibiting Streptomyces AcH 1003 suggest an (oxidative) stress
response of the fungus