Soliton structures in a molecular chain model with saturation

In the present work, we study, by means of a one-dimensional lattice model, the collective excitations corresponding to intra molecular ones of a chain like proteins. It is shown that such excitations are described by the Nonlinear Schrodinger equation with saturation. The solutions obtained here are the bell solitons, bubbles, kinks and crowdons. Since they belong to different sectors on the parametric space, the bubble condensation could give place to some important changes of face in this kind of nonlinear system. Additionally, it is shown that the limiting velocity of the solitons is the velocity of sound waves corresponding to longitudinal vibrations of molecules.Comment: 12 pages, 4 figure

Contribution to the sustainability of agricultural production in greenhouses built on slope soils: a numerical study of the microclimatic behavior of a typical Colombian structure

This is the final version. Available from MDPI via the DOI in this record. The use of covered structures is an alternative increasingly used by farmers to increase crop yields per unit area compared to open field production. In Latin American countries such as Colombia, productive areas are located in with predominantly hillside soil conditions. In the last two decades, farmers have introduced cover structures adapted to these soil conditions, structures for which the behavior of factors that directly affect plant growth and development, such as microclimate, are still unknown. Therefore, in this research work, a CFD-3D model successfully validated with experimental data of temperature and air velocity was implemented. The numerical model was used to determine the behavior of air flow patterns and temperature distribution inside a Colombian passive greenhouse during daytime hours. The results showed that the slope of the terrain affects the behavior of the air flow patterns, generating thermal gradients inside the greenhouse with values between 1.26 and 16.93 ◦C for the hours evaluated. It was also found that the highest indoor temperature values at the same time were located in the highest region of the terrain. Based on the results of this study, future researches on how to optimize the microclimatic conditions of this type of sustainable productive system can be carried out

Análisis psicométrico y validez de la Escala de Disposición al Aprendizaje Interprofesional en estudiantes de enfermería en Chile

Introduction: Interprofessional education offers health students an opportunity to learn, practice, and improve communication and collaboration skills through learning experiences with other professions. It is important to determine their willingness to actively engage with other students in their learning process, which is assessed through the Readiness for Interprofessional Learning scale, one of the most widely used internationally. The objective was to adapt and validate the Readiness for Interprofessional Learning Scale to Spanish among nursing students.Method: The study design was cross-sectional quantitative, with a sample of 330 nursing students of different years. Cronbach's Alpha and exploratory and confirmatory factor analysis were performed.Results: The original scale had 23 items, only 16 met the validity and reliability criteria. The 16 items are distributed in the dimensions: Teamwork and collaboration (T: 10 items), Patient Centered Work (EP: 4 items) and Professional identity (PI: 2 items). Cronbach's alpha index for the full scale was 0.8259 (CyTE α=0.81; PC α= 0.77 and PI α=0.61).Conclusion: the RIPL scale validated in this study has adequate reliability and validity for the dimensions Teamwork and collaboration and Patient Centered Work. Elaboration of new items are required for Professional IdentityIntroducción: La educación interprofesional ofrece a los estudiantes de salud una oportunidad para aprender, practicar y mejorar las habilidades de comunicación y colaboración a través de la experiencia de aprendizaje con otras profesiones. Es importante determinar la disposición que tienen de involucrarse activamente con otros estudiantes en su proceso de aprendizaje, lo que se evalúa a través de la Escala de disposición al aprendizaje interprofesional, una de las más usadas internacionalmente. El objetivo fue adaptar y validar al español la Escala de disposición al aprendizaje interprofesional (RIPLS) en estudiantes de enfermería.Método: Diseño de estudio cuantitativo transversal, a una muestra de 330 estudiantes de enfermería de diferentes años, se realizó Alfa de Cronbach y análisis factorial exploratorio y confirmatorio.Resultados: La escala original tenía 23 ítems, solo 16 cumplen con los criterios de validez y confiabilidad. Los 16 ítems, se distribuyen en las dimensiones: Colaboración y trabajo en equipo (CyTE: 10 ítems), Trabajo centrado en el paciente (PC: 4 ítems) y Sentido e Identidad Profesional (PI: 2 ítems). El índice alfa de Cronbach de la escala completa fue de 0.8259 (CyTE α=0.81; PC α= 0.77 and PI α=0.61).Conclusión: La escala RIPL validada en este estudio tiene confiabilidad y validez adecuada para las dimensiones Trabajo en equipo y colaboración y Trabajo centrado en el paciente. Se requiere elaborar nuevos ítems para Sentido e Identidad profesional

Características y distribución de la maleza Amaranthus palmeri S. Watson (Amaranthaceae) en cultivos de soja y maíz de la provincia de Tucumán y del NOA

Amaranthus palmeri (“ataco”, “yuyo colorado”, “bledo”) es una maleza introducida desde el hemisferio norte y que fue detectada en Argentina en las campañas de 2011 – 2012 debido a su resistencia a glifosato y a inhibidores de ALS (Tuesca et.al., 2012). Morichetti et al. (2013) mencionan que en nuestro país, ya en 1966, fue coleccionada por J. H. Hunziker y G. Covas, no volviendo a ser citada ni incluida en la flora adventicia quizás por no haber logrado establecerse exitosamente. Pero, colecciones realizadas en 2012 en diferentes lotes cultivados con soja, maní, sorgo y maíz en el Sur de Córdoba y San Luis, permiten ahora incluirla como una maleza establecida y problemática de nuestra flora adventicia. El grave problema que también plantea esta maleza es que puede hibridarse con otras especies de Amaranthus, con lo cual puede transferir genes de resistencia hacia otras especies del Género (Morichetti et. al., 2013).Fil: Villagran, Liliana Fernanda. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabrera, Debora Carina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de la Vega, M.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Figueroa, O.. Asociación Argentina de Consorcios Regionales de Experimentación Agrícola; ArgentinaFil: Castro, E.. Asociación Argentina de Consorcios Regionales de Experimentación Agrícola; ArgentinaFil: Rossi, D.. Asociación Argentina de Consorcios Regionales de Experimentación Agrícola; Argentin

Shell we cook it? An experimental approach to the microarchaeological record of shellfish roasting

In this paper, we investigate the microarchaeological traces and archaeological visibility of shellfish cooking activities through a series of experimental procedures with direct roasting using wood-fueled fires and controlled heating in a muffle furnace. An interdisciplinary geoarchacological approach, combining micromorphology, FTIR (in transmission and ATR collection modes), TGA and XRD, was used to establish a baseline on the mineralogical transformation of heated shells from aragonite to calcite and diagnostic sedimentary traces produced by roasting fire features. Our experimental design focused on three main types of roasting procedures: the construction of shallow depressions with heated rocks (pebble cuvette experiments), placing shellfish on top of hot embers and ashes (fire below experiment), and by kindling short-lived fires on top of shellfish (fire above experiments). Our results suggest that similar shellfish roasting procedures will largely create microstratigraphic signatures of anthropogenically reworked combusted material spatially "disconnected" from the actual combustion locus. The construction of shallow earth ovens might entail an increased archaeological visibility, and some diagnostic signatures of in situ hearths can be obtained by fire below roasting activities. We also show that macroscopic visual modifications and mineralogical characterization of discarded shellfish might be indicative of specific cooking activities versus secondary burning.Max Planck Societyinfo:eu-repo/semantics/publishedVersio

Barred-beach morphological control on infragravity motion

A conceptual analysis of the coupling between bars and infragravity waves is performed combining laboratory experiments and numerical modeling. Experiments are carried out in a wave flume with a barred profile. The Boussinesq fully-nonlinear model SERR1D is validated with the laboratory data and a sensitivity analysis is performed next to study the influence on the infragravity wave dynamics of bar amplitude and location, and swash zone slope. A novel technique of incident and reflected motions separation that conserves temporal characteristics is applied. We observe that changing bar characteristics induces substantial variations in trapped energy. Interestingly, a modification of swash zone slope has a large influence on the reflected component, controlling amplitude and phase time-lag, and consequently on the resonant pattern. Variations of trapped infragravity energy induced by changes of swash zone slope reach 25 %. These changes in infragravity pattern consequently affect short-wave dynamics by modifying the breakpoint location and the breaking intensity. Our conceptual investigation suggests the existence of a morphological feedback through the action of evolving morphology on infragravity structures which modulates the action of short-waves on the morphology itself

Succinate in dystrophic white matter: A proton magnetic resonance spectroscopy finding characteristic for complex II deficiency

A deficiency of succinate dehydrogenase is a rare cause of mitochondrial encephalomyopathy. Three patients, 2 sisters and I boy from an unrelated family, presented with symptoms and magnetic resonance imaging signs of leukoencephalopathy. Localized proton magnetic resonance spectroscopy indicated a prominent singlet at 2.40ppm in cerebral and cerebellar white matter not present in gray matter or basal ganglia. The signal was also elevated in cerebrospinal fluid and could be identified as originating from the two equivalent methylene groups of succinate. Subsequently, an isolated deficiency of complex II (succinate:ubiquinone oxidoreductase) was demonstrated in 2 patients in muscle and fibroblasts. One of the sisters died at the age of 18 months. Postmortem examination showed the neuropathological characteristics of Leigh syndrome. Her younger sister, now 12 months old, is also severely affected; the boy, now 6 years old, follows a Milder, fluctuating clinical course. Magnetic resonance spectroscopy provides a characteristic pattern in succinate dehydrogenase deficiency

Relentless increase of resistance to fluoroquinolones and expanded-spectrum cephalosporins in Escherichia coli: 20 years of surveillance in resource-limited settings from Latin America.

AbstractPrevious studies on commensal Escherichia coli from healthy children in the Bolivian Chaco have shown remarkable resistance rates to the old antibiotics since the early 1990s, and the emergence of resistance to newer drugs (fluoroquinolones and expanded-spectrum cephalosporins) in the 2000s. Here we report the results of a new survey conducted in 2011 in the same setting. Rectal swabs were obtained from 482 healthy children (aged 6–72 months) from three urban areas of the Bolivian Chaco. Screening for antibiotic-resistant E. coli was performed by a direct plating method, as in the previous studies. The blaCTX-M genes were investigated by PCR/sequencing, and CTX-M-producing isolates were subjected to genotyping and detection of several plasmid-mediated quinolone resistance mechanisms. Results showed high rates of resistance to nalidixic acid (76%), ciprofloxacin (44%) and expanded-spectrum cephalosporins (12.4%), demonstrating a relentless increase of resistance to those drugs over the past two decades. CTX-M-type extended-spectrum beta-lactamases were found to be widespread (12%, 97% of extended-spectrum beta-lactamase producers). Compared with the previous studies, CTX-M-producing E. coli underwent a dramatic dissemination (120-fold increase since early 2000s) and a radical change of dominant CTX-M groups (CTX-M-1 and CTX-M-9 groups versus CTX-M-2 group). Most CTX-M producers were not susceptible to quinolones (91%), and 55% carried plasmid-mediated quinolone resistance genes (different combinations of aac(6')-Ib-cr, qnrB and qepA). This study shows the rapid and remarkable increasing trend for resistance to fluoroquinolones and expanded-spectrum cephalosporins in one of the poorest regions of Latin America, and underscores the need for urgent control strategies aimed at preserving the efficacy of those drugs in similar settings

Long-Standing International Cooperation in Parasitology Research: A Summary of 35 Years of Activities in the Bolivian Chaco

The Bolivian Chaco is a semiarid region with a low population density, situated in the southeast part of the Plurinational State of Bolivia. Here, despite the improvements of the last 15 years, poverty remains high in rural areas, where social vulnerability is widespread. The Guaraní ethnic group often lives in isolated communities with a low standard of hygiene and sanitation. This epidemiological scenario favors the spread of transmissible diseases, including several parasitic infections belonging to the neglected tropical diseases (NTDs) group. In this area, a long-standing research activity, built upon the synergism between local and foreign institutions, has been established since the late 1980s and helps to fill in the knowledge gap about the epidemiology dynamics of soil-transmitted helminths, vector-borne parasites, and other parasitic diseases. A 35-year history of cooperation programs in parasitology research has contributed to informing local health authorities of the NTD burden in the Bolivian Chaco and, ultimately, supports local healthcare providers in the management of parasitic diseases