Time filter

Source Type

De-Sola J.,Complutense University of Madrid | Talledo H.,Saint Ignatius of Loyola University | Rubio G.,Hospital Universitario 12 Of Octubre | de Fonseca F.R.,Complutense University of Madrid | And 2 more authors.
Frontiers in Psychiatry | Year: 2017

This research aims to study the existing relationships among the factors of state anxiety, depression, impulsivity, and alcohol consumption regarding problematic mobile phone use, as assessed by the Mobile Phone Problem Use Scale. The study was conducted among 1,126 participants recruited among the general Spanish population, aged 16-65 years, by assessing the predictive value of these variables regarding this problematic use. Initially tobacco use was also considered being subsequently refused because of the low internal consistency of the scale used. In general terms, the results show that this problematic use is mainly related to state anxiety and impulsivity, through the dimensions of Positive and Negative Urgency. Considering its predictive value, multiple regression analysis reveals that state anxiety, positive and negative urgency, and alcohol consumption may predict problematic mobile phone use, ruling out the influence of depression. © 2017 De-Sola, Talledo, Rubio and de Fonseca.


Perez F.C.,Amec Foster Wheeler | Ale J.D.,Saint Ignatius of Loyola University
Proceedings of the 5th International Conference on Geotechnical and Geophysical Site Characterisation, ISC 2016 | Year: 2016

In this research a dynamic characterization in function of mean stress of share wave velocities and his corresponding maximum shear modulus (Vs, Gmax) of ROM (run of mine) ore stacking were carried out based on MASW survey. In addition a triaxial compression tests (consolidated undrained, CU of 6″ diameter) have been carried out to determine the mechanical properties of the ROM ore stacking of sandstone crushed material. The study has focused on the understanding of the two-dimensional non-linear dynamic response of a heap leach pad located in a higher seismicity Andean region of Peru. This geostructure modeled in Finite Differences Method software (FLAC, Itasca) was subjected to an Operating Basis Earthquake (OBE) obtained from a spectral matching in the time domain (Abrahamson, 1993). A constitutive Mohr-Coulomb Model with stress-level dependent is used to simulate the stress-strain behavior of the ore material. The slope stability and the permanent deformations at the end of this excitation are evaluated. As well as, the development of the deformations during the earthquake are present here in. © 2016 Australian Geomechanics Society.


CACERES A.,Saint Ignatius of Loyola University | MELO M.,University of Cape Town | BARLOW J.,Lancaster University | FAUSTINO DE LIMA R.,University of Lisbon | MILLS M.S.L.,Plateau State University
Bird Conservation International | Year: 2017

Natural habitats are being rapidly lost due to human activities. It is therefore vital to understand how these activities influence biodiversity so that suitable guidelines can be established for conservation. This is particularly important in understudied, high biodiversity, areas such as the Angolan Escarpment. Here we examine which habitat characteristics drive bird diversity and endemic species presence at Kumbira Forest, a key site in the Central Escarpment Forest. Bird diversity was sampled by 10 min bird point counts, whereas habitat characteristics were measured by a combination of ground-based vegetation surveys and remotely sensed data modelling of Landsat images. GLM, multi-model inference and model averaging were used to determine the most important variables driving species richness and the presence of endemics. The remote sensing variables performed poorly in predicting presence of Red-crested Turaco Tauraco erythrolophus and Gabela Bushshrike Laniarius amboimensis but they contributed significantly to explain species richness and Gabela Akalat Sheppardia gabela presence, both of which were associated with greater canopy cover. Liana density and elevation were also important explanatory variables in certain cases. Conservation actions at Kumbira should focus on increasing canopy cover and maintaining forest integrity (as measured by liana density), as these actions are likely to have the most positive outcomes for the avifauna. Copyright © BirdLife International 2017


Cardenas-Quintana H.,Federico Villarreal National University | Roldan Arbieto L.,Saint Ignatius of Loyola University
Revista Chilena de Nutricion | Year: 2013

Objective: To determine the nutritional status of non-institutionalized elderly (NE) and their relationship with different socioeconomic conditions. Method: 300 NE residents of Metropolitan Lima from different socioeconomic levels were randomly selected. The nutritional status was determined using Body Mass Index (BMI) and brachial perimeter. The NE was classified according to BMI: normal from 22 to 27, overweight from 27.1 to 29.9 and obesity ≥ 30 kg/m2. The dietary intake was evaluated with a reminder survey of 24 hours. Results: The prevalence of overweight was 48.3% (26% overweight and 22.3% obese) without significant differences between socioeconomic levels (SS) (p=0.088). Greater obesity in women than in men was observed with significant differences between SS (p=0.030). The highest prevalence of obesity was observed in females of SS medium (32%). The SS significantly influenced lipid consumption, vitamin C and calcium. The consumption of energy, protein, carbohydrates, fiber, iron and phosphorus, did not differ significantly with SS. Conclusions: The nutritional status and nutrient intake of NE showed no relation with socioeconomic level.


Un Jan A.,Saint Ignatius of Loyola University | Contreras V.,Cantaros Peruanos
Computers in Human Behavior | Year: 2016

The purpose of this paper is to propose a model to anticipate the success in the use of a Knowledge Management System (KMS) by doctoral researchers. Doctoral researchers who are preparing their doctoral dissertation are requested to prepare a tool to manage the knowledge they are collecting. The tool is based on data base techniques, and the researchers will use this tool to collect data about the knowledge they use. Doctoral researchers will perceive satisfaction in the use of this tool, depending on internal aspects that they could previously perceive, such as ease of use, usefulness, or quality. Also, there could be external aspects such as rewards, trust and social norms that could affect the perceived satisfaction. As a conclusion, the correct identification of internal and external aspects can improve the success in the use of a KMS. © 2016 Elsevier Ltd. All rights reserved.


Cisneros F.H.,Saint Ignatius of Loyola University | Paredes D.,Saint Ignatius of Loyola University | Arana A.,Saint Ignatius of Loyola University | Cisneros-Zevallos L.,Texas A&M University
Journal of Agricultural and Food Chemistry | Year: 2014

The effect of roasting of Sacha-inchi (Plukenetia volubilis L.) seeds on the oxidative stability and composition of its oil was investigated. The seeds were subjected to light, medium and high roasting intensities. Oil samples were subjected to high-temperature storage at 60 °C for 30 days and evaluated for oxidation (peroxide value and p-anisidine), antioxidant activity (total phenols and DPPH assay), and composition (tocopherol content and fatty acid profile). Results showed that roasting partially increased oil oxidation and its antioxidant capacity, slightly decreased tocopherol content, and did not affect the fatty acid profile. During storage, oxidation increased for all oil samples, but at a slower rate for oils from roasted seeds, likely due to its higher antioxidant capacity. Also, tocopherol content decreased significantly, and a slight modification of the fatty acid profile suggested that α-linolenic acid oxidized more readily than other fatty acids present. © 2014 American Chemical Society.


Pacheco M.P.,Saint Ignatius of Loyola University | Velazquez M.G.N.,Research Center en Quimica Aplicada | Escamilla G.C.,Research Center Cientifica Of Yucatan Ac
Revista Latinoamericana de Metalurgia y Materiales | Year: 2016

In this work we have studied the permeability of polymer films that had a core and shell composed by polystyrene and poly (butyl acrylate) in a mass relation of 40 and 60, respectively. Permeability coefficient measurements were made in the Permeation Chamber "Voyager". The permeated gases were nitrogen, oxygen, methane and carbon dioxide at a temperature of 35 °C and pressures of 2 and 4 atmospheres. According to the results, the permeabilities of the films using latex obtained by polymerization in microemulsion were lower compared to those obtained using latex core-shell polymer obtained by emulsion polymerization and this is due to that smaller diameter nanoparticles were obtained by microemulsion polymerization than those obtained by emulsion. Also, a direct relationship between the coefficient of permeability of gases with critical temperatures of the gases was found.


Sotomayor S.,Saint Ignatius of Loyola University | Barbieri C.,North Carolina State University
International Journal of Tourism Research | Year: 2016

Surf tourism is a multibillion dollar industry expected to continue expanding. Despite such economic significance, the surf tourism literature has gaps related to surf tourism segments. In response, this study applied the serious leisure framework to profile serious surfers and contrast their sociodemographic composition and travel behaviors. Although more serious surfers are more avid travelers in the quest for the perfect wave as compared with less serious surfers, preference for local attractions and conveniences did not vary between groups. In addition to contributing the scholarship of serious leisure and surf tourism, this study provides insights for the surf tourism industry. © 2015 John Wiley & Sons, Ltd.


Becerra-Castro E.M.,Saint Ignatius of Loyola University | Becerra-Castro E.M.,Agrarian National University | De Araujo L.E.E.,University of Campinas
Journal of the Optical Society of America B: Optical Physics | Year: 2016

We describe cross focusing in a four-level atomic medium under electromagnetically induced transparency. We show that due to the giant Kerr nonlinearity experienced by the atoms, cross focusing between weak signal and probe fields (both fields with intensities below line saturation level) is possible. By applying different intensity masks to the signal field, different lenses (cylindrical, Fresnel, Gaussian) can be induced in the atomic sample. Focusing of the probe beam is analyzed in terms of the excitation parameters (signal Rabi frequency and detuning, as well as optical depth of the atomic medium). © 2016 Optical Society of America.


Gutierrez-Cardenas J.M.,Saint Ignatius of Loyola University
Proceedings - IEEE 38th Annual International Computers, Software and Applications Conference Workshops, COMPSACW 2014 | Year: 2014

Steganography is the art of concealing information within different types of media objects such as images or audio files. Its counterpart, Steganalysis, is the study of methods that uncover information in a suspicious file, which has being altered for stego purposes. Its techniques rely on the inspection of changes at the pixel information level. In this paper, we propose a method for Secret-key Steganography that uses a picture to conceal a message with unaltered pixel information, so it would be secure against Steganalysis inspection techniques. This is possible using a technique derived from code obfuscation using random numbers. In summary, we will modify the stego-key transmitted during the communication process, which maps the information in the unaltered cover image. So the original message will be reconstructed by the receiver using the seeds of Pseudo-Random Number Generators, included in the stego-key. The proposed technique is secure against classical steganalysis attacks because it leaves the original and generated stego images unchanged. © 2014 IEEE.

Loading Saint Ignatius of Loyola University collaborators
Loading Saint Ignatius of Loyola University collaborators