IT Impact on Management Education Using the Case Method

Information technology (IT) has become rapidly accepted as a complement or substitute of the traditional learning setting, hence challenging Management education. This research examines the impact of IT platforms on Management education using the case method. We theorize that traditional learning platforms may enable instructors to engage students to increase learning performance, which in turn leads to a greater student satisfaction. Social media applications (i.e., social media for teaching activities) may amplify the relationships between traditional learning platforms, student engagement, learning performance, and student satisfaction. Using the variance-structural equation modeling technique, and the partial least squares method of estimation on a combination of survey and secondary data from 94 Spanish students from a Management course, the empirical analysis gives support to our theory

Electron Transport and Ion Diffusivity through the Solid Electrolyte Interphase in Lithium Ion Batteries with Silicon Anodes

Lithium-ion batteries (LIB) are the best option among batteries for portable electronic, power tools, and electric vehicles due to their higher energy storage, higher power, and lighter weight than other battery technologies such as Ni-based or lead acid. However, Li-ion batteries still face challenges such as safety, life, performance, and cost. One way to contribute to the solutions of these challenges and, consequently, improve the performance of Li-ion cells is to develop and design more stable passivation films at the electrode-electrolyte interface. Therefore, having a better understanding of the molecular processes that lead to the nucleation, growth, structure and morphology, as well as the electron and ion transport properties of the solid electrolyte interphase (SEI) is highly important for the development of new or improved lithium-ion batteries. In this work, computational methods, which allow studying phenomena not easily observable with experimental techniques, are used to study the electron transfer characteristics and the lithium ion diffusivity of the materials found in the SEI film formed in LIB with silicon anodes. First, ab initio computational methods are used to study the electron transfer through selected finite models of SEI films formed at the anode-electrolyte interface. A combined ab initio density functional theory (DFT) and Green’s functions approach, as implemented in the Generalized Electron Nano-Interface Program (GENIP), is used to calculate the current-voltage characteristics of selected SEI configurations. The models studied consist of a LixSiy cluster, a SEI product (LiF, Li2O or Li2CO3), and an electrolyte component, ethylene carbonate (EC). Various parameters are considered in the investigation including: various lithiated states for the anode; several thicknesses and configurations for the SEI layer; and the presence of surface oxides (SiO2 and Li2Si2O5). The trend of conductance is found to be Li2O > SiO2 > LiF > Li2CO3 > Li2Si2O5, at the same applied voltage and anode configuration. Then, lithium-ion diffusion is studied in the main components of the SEI layer using classical molecular dynamics (MD) simulations in order to provide insights and to calculate the diffusion coefficients of Li-ions at temperatures in the range of 250 K to 400 K. The compounds studied are lithium fluoride (LiF), lithium oxide (Li2O) and lithium carbonate (Li2CO3). A slight increase in the diffusivity as the temperature increases is found and since diffusion is noticeable at high temperatures, Li-ion diffusion in the range of 1300 to 1800 K is also studied and the diffusion mechanisms involved in each SEI compound are analyzed. The mechanisms of Li-ion diffusion observed include vacancy assisted and knock-off diffusion in LiF, direct exchange in Li2O, and vacancy and knock-off in Li2CO3. Moreover, the effect that an applied an electric field has in the diffusion of Li-ions at room temperature is also evaluated. The long-term goal is to eventually have more control over interface parameters such as composition, structure, porosity and thickness, and thus accurately design SEI films and therefore better Li-ion batteries. This work is a step towards this ultimate goal

Transformaciones territoriales en áreas de riesgo y vulnerabilidad

El presente trabajo tiene como objetivo realizar el estudio de los cambios territoriales a partir de la evolución en los usos de suelo y la estructura morfológica urbana en uno de los asentamientos poblacionales situados en las márgenes del arroyo El Gato. El mismo se llevará a cabo a partir de la implementación de la teledetección, con la lectura y análisis de fotografías aéreas de la zona, en varios cortes temporales: 1984, 1996 y 2004. El estudio de tales variables permitirá determinar áreas de riesgo hídrico en el área de estudio en cuestión, en el marco del trabajo realizado por el equipo abocado al estudio de inundaciones en la provincia de Buenos Aires y teniendo el cuenta, entre otros, los conceptos de riesgo y vulnerabilidad que sustentan la teoría en la cual se enmarca este equipo de trabajo

The red-bellied squirrel in Argentina and the management of introduced species as a biological and social problem

El estudio y manejo de especies exóticas invasoras ha estado principalmente enfocado en conocer el proceso de invasión y técnicas adecuadas de manejo. Sin embargo, en los últimos años los estudios que promueven la participación de diferentes grupos sociales de la comunidad en los planes de manejo han cobrado importancia. En este trabajo describimos las opiniones y actitudes predominantes de seis grupos sociales (productores y prestadores de servicios, ambientalistas, vecinos, personal de áreas protegidas, funcionarios y docentes) con respecto a la presencia de la ardilla de vientre rojo introducida en Argentina. La existencia de varios focos de invasión de ardillas en tres provincias argentinas se relaciona con liberaciones intencionales de ardillas, en ocasiones obtenidas por comercio ilegal. Las opiniones con respecto a la presencia de ardillas variaron desde una percepción negativa que consideraba que era una especie problema que debía ser controlada hasta una percepción positiva que sostiene que es una especie atractiva y vistosa. Algunos grupos mostraron una opinión predominante, mientras que otros reflejaron todo el rango de respuestas. La experiencia directa con la especie, sus atributos y el tiempo desde su introducción, el área de residencia y el grado de conocimiento sobre la problemática influyen sobre las opiniones y actitudes de las personas. Las alternativas de manejo deben planificarse para cada zona invadida teniendo en cuenta las particularidades no sólo biológicas y económicas, sino también sociales y políticas. Al mismo tiempo, resulta imprescindible una  estrategia nacional de prevención para frenar la aparición de nuevos focos de invasión. Para esto es fundamental desarrollar estrategias que reorienten la relación de las personas con los recursos del ambiente y promuevan la valoración de los ecosistemas locales y especies nativas, así como la co-responsabilidad y la participación ciudadana en la problemática de las invasiones biológicas, el tráfico de fauna y la tenencia de mascotas.The study and management of exotic invasive species has been mainly focused on understanding the invasion process and designing adequate management techniques; however, in recent years several studies have shown the importance of involving social groups of the local community in the implementation of management plans. In this study we describe opinions and attitudes of six social groups (producers and service providers, environmentalists, neighbours, personnel of protected areas, civil servants, and teachers) regarding the presence of the red-bellied squirrels introduced in Argentina. The occurrence of various invasion foci of squirrels in three Argentinian provinces results from intentional releases of individuals, sometimes obtained by illegal trade. Opinion towards the presence of squirrels ranged from a negative perception of the squirrels viewed as a problem species that needs to be controlled to a positive perception of the squirrels viewed as an attractive species. Some groups showed a predominant opinion while others reflected the whole range of responses. Personal experience with the species, its attributes and the time since its introduction, the area of residency, and the knowledge of the problems posed by this species affect the opinion and attitudes towards the presence of red-bellied squirrels. Management plans must be designed for each invasion focus not only considering biological and economic issues, but also social and political ones. At the same time, a national strategy of prevention to stop the creation of new invasion foci is urgently needed. We therefore need strategies to reorient the relationship between people and environmental resources and to promote appreciation of local ecosystems and native species as much as co-responsibility and citizen participation in the problems posed by biological invasions, and the illegal trade of wild fauna and pets.Fil: Borgnia, Mariela. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Benitez, Verónica Victoria. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Gozzi, Cecilia. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Guichon, Maria Laura. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; Argentin

Deep Learning-based Fingerprinting for Outdoor UE Positioning Utilising Spatially Correlated RSSs of 5G Networks

Outdoor user equipment (UE) localisation has attracted a significant amount of attention due to its importance in many location-based services. Typically, in rural and open areas, global navigation satellite systems (GNSS) can provide an accurate and reliable localisation performance. However, in urban areas GNSS localisation accuracy is significantly reduced due to shadowing, scattering and signal blockages. In this work, the UE positioning assisted by deep learning in 5G and beyond networks is investigated in an urban area environment. We study the impact of utilising the spatial correlation in the received signal strengths (RSSs) on the UE positioning accuracy and how to utilise such correlation with deep learning algorithms to improve the localisation accuracy. Numerical results showed the importance of utilising the spatial correlation in the RSS to improve the prediction accuracy for all of the considered models. In addition, the impact of varying the number of access points (APs) transmitters on the localisation accuracy is also investigated. Numerical results showed that a lower number of APs may be sufficient when not considering uncertainties in RSS measurements. Moreover, we study how much the degrading effect of RSS uncertainty can be compensated for by increasing the number of APs.Peer reviewe

Hydrothermal Treatment to Remove Tannins in Wholegrains Sorghum, Milled Grains and Flour

Pigmented sorghum with high content of tannins were studied in this work. Tannins bind to proteins and reduce their availability. A hydrothermal treatment was carried out to reduce tannins. A control sample of non-pigmented pericarp variety was used. After the treatment, grains were milled, and a part was separated for wholegrain flour elaboration. Several determinations were done after treatment: tannins (T), total antioxidant capacity (TAC) and total polyphenols (TPP) content. TPP and TAC in wholegrain pigmented sorghum were 3.9 to 12.3 and 2.3 to 3.5 times higher than those of non-pigmented sorghum, respectively. In all sorghum varieties the extractions of TPP decreased with milling. TAC in flour increased 3.3 times the initial value for non-pigmented sorghum, whereas for the other sorghum samples it increased slightly from 1.1 to 1.3 times the initial value. In flours there was a noticeable reduction in T, with respect to the wholegrain. It was possible to conclude that the hydrothermal treatment allowed lower levels of tannins than those established in the Codex for both wholegrain sorghum and flour. This reduction makes it possible to obtain flour which may be suitable for food processing and the recovery of tannins for other uses.Fil: Acquisgrana, María del Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Tecnológica Nacional. Facultad Regional Resistencia. Departamento de Ingeniería Química. Laboratorio de Química Teórica y Experimental; ArgentinaFil: Gómez Pamies, Laura Cecilia. Universidad Tecnológica Nacional. Facultad Regional Resistencia. Departamento de Ingeniería Química. Laboratorio de Química Teórica y Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Benitez, Elisa Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Universidad Tecnológica Nacional. Facultad Regional Resistencia. Departamento de Ingeniería Química. Laboratorio de Química Teórica y Experimental; Argentin

A century of Shope Papillomavirus in museum rabbit specimens

Sylvilagus floridanus Papillomavirus (SfPV) causes growth of large horn-like tumors on rabbits. SfPV was described in cottontail rabbits (probably Sylvilagus floridanus) from Kansa and Iowa by Richard Shope in 1933, and detected in S. audubonii in 2011. It is known almost exclusively from the US Midwest. We explored the University of Kansas Natural History Museum for historical museum specimens infected with SfPV, using molecular techniques, to assess if additional wild species host SfPV, and whether SfPV occurs throughout the host range, or just in the Midwest. Secondary aims were to detect distinct strains, and evidence for strain spatio-temporal specificity. We found 20 of 1395 rabbits in the KU collection SfPV symptomatic. Three of 17 lagomorph species (S. nuttallii, and the two known hosts) were symptomatic, while Brachylagus, Lepus and eight additional Sylvilagus species were not. 13 symptomatic individuals were positive by molecular testing, including the first S. nuttallii detection. Prevalence of symptomatic individuals was significantly higher in Sylvilagus (1.8%) than Lepus. Half of these specimens came from Kansas, though new molecular detections were obtained from Jalisco—Mexico’s first—and Nebraska, Nevada, New Mexico, and Texas, USA. We document the oldest lab-confirmed case (Kansas, 1915), predating Shope’s first case. SfPV amplification was possible from 63.2% of symptomatic museum specimens. Using multiple methodologies, rolling circle amplification and, multiple isothermal displacement amplification in addition to PCR, greatly improved detection rates. Short sequences were obtained from six individuals for two genes. L1 gene sequences were identical to all previously detected sequences; E7 gene sequences, were more variable, yielding five distinct SfPV1 strains that differing by less than 2% from strains circulating in the Midwest and Mexico, between 1915 and 2005. Our results do not clarify whether strains are host species specific, though they are consistent with SfPV specificity to genus Sylvilagus.Costs of lab work were funded by the Spanish Ministry of Science and Innovation, (Ref CGL2010-15734/BOS) awarded to JPT. RW was supported by the Programa Internacional de Captación de Talento (PICATA) de Moncloa Campus de Excelencia Internacional(http://www.campusmoncloa.es/en/calls/picata.php) while writing the manuscript. The authors thank The One University Open Access Author Fund at The University of Kansas for funding this publication. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Three component-based bi-layer and ecofriendly mulching films.

Among the agronomic practices usually employed to achieve more successful culture results, mulching (M) has been applied using a variety of materials. In particular, the employment of plastic M films has made a revolution since they offer an evapotranspiration decrease whereas the soil temperature is also controlled, thus leading to an earlier crop maturation. Additionally, pests are more easily controlled, as well as both the possible soil erosion and farming products lose due to rainfalls are minimized. Then, less herbicides and pesticides use, and a more efficient employment of water resources is achieved. As a result of this, M improves the soils organic and nutritional characteristics even though investing fewer resources than in traditional culturing. However, although plastic M has multiple benefits, some negative impacts are also associated with this farming implement. Since most plastic mulches are non-biodegradable and non-reusable, there is a necessity to remove them from the fields, and further stockpile, transport or even burn them. In the present research work bi-layer M films (Figure 1a) were prepared through simple and low-cost procedures from biodegradable, natural and renewable resources, minimizing the employment of both energy and auxiliary substances. Thus, the global objective was to straightforwardly improve agronomical practices by introducing the use of materials complying with the green chemistry, green engineering and circular economy principles. For this, poly-lactic acid (PLA), sulfated cellulose nanocrystals (S-CNC) and chitosan (CH) were employed as starting materials to develop a bi-layer eco-friendly system composed by a top hydrophobic layer (PLA) and an interior hydrophilic one (S-CNC:CH). The hydrophilic layer was prepared by forming polyelectrolyte complexes (PEC). CH was included to offer anti-microbial and elicitor capabilities.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Gastro-intestinal helminths in the red-bellied squirrel introduced in Argentina: accidental acquisitions and lack of specific parasites

Introduced species may lose their natural parasites when invading a new habitat, may acquire new, local parasites or may introduce parasites from their native range. We studied the gastro-intestinal helminth fauna associated with the red-bellied squirrel Callosciurus erythraeus (Pallas, 1778) introduced in Argentina to evaluate its role as a host of either specific or acquired parasites in two invasion foci. We analyzed entire digestive tracts of 72 red-bellied squirrels captured in the main invasion focus (Luján, province of Buenos Aires) between February and May 2011, and in a secondary focus (Cañada de Gómez, province of Santa Fe) in December 2008. We only found two nematode specimens: an adult male belonging to the genus Pterygodermatites (Paucipectines) Quentin, 1969 and another adult male belonging to the genus Stilestrongylus (Freitas, Lent and Almeida, 1973). None of these genera were previously listed for the red-bellied squirrel in introduced areas, but a species of the genus Pterygodermatites was previously reported for this squirrel in its native habitat. These results indicate that, to date, the red-bellied squirrel in Argentina is accidentally parasitised by nematodes acquired in its new environment and has no specific gastro-intestinal helminths. This could be related with a “founder effect” and/or the lack of sciurid rodents that prevent the red-bellied squirrel to be colonized by pre-adapted helminth taxa. Other factors that may play a role are the small number of mammals with arboreal habits and some “encounter barriers” in the new environment that prevent the acquisition of helminths with a wide host spectrum.Fil: Gozzi, Ana Cecilia. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Grupo de Estudios en Ecología de Mamíferos; ArgentinaFil: Guichon, Maria Laura. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Grupo de Estudios en Ecología de Mamíferos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación en Biodiversidad y Medioambiente; ArgentinaFil: Benitez, Verónica Victoria. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Grupo de Estudios en Ecología de Mamíferos; ArgentinaFil: Troyelli, Adrián. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Grupo de Estudios en Ecología de Mamíferos; ArgentinaFil: Navone, Graciela Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Estudios Parasitológicos y de Vectores (i); Argentin