On Pillai’s problem with X-coordinates of Pell equations and powers of 2 II

In this paper, we show that if (X_n, Y_n) is the nth solution of the Pell equation X^2−dY^2= ±1 for some non-square d, then given any int eger c, the equation c = X_n−2^m has at most 2 integer solutions (n, m)withn ≥ 0andm ≥ 0, except for the only pair (c, d)=(−1, 2). Moreover, we show that this bound is optimal. Additionally, we propose a conjecture about the number of solutions of Pillai’s problem in linear recurrent sequences

Psychophysiological correlates of peritraumatic dissociative responses in survivors of life-threatening cardiac events

The psychophysiological startle response pattern associated with peritraumatic dissociation (DISS) was studied in 103 survivors of a life-threatening cardiac event (mean age 61.0 years, SD 13.95). Mean time period since the cardiac event was 37 (79 IQD) months. All patients underwent a psychodiagnostic evaluation (including the Peritraumatic Dissociative Experiences Questionnaire) and a psychophysiological startle experience which comprised the delivery of 15 acoustic startle trials. Magnitude and habituation to trials were measured by means of electromyogram (EMG) and skin conductance responses (SCR). Thirty-two (31%) subjects were indexed as patients with a clinically significant level of DISS symptoms. High-level DISS was associated with a higher magnitude of SCR (ANOVA for repeated measures p = 0.017) and EMG (p = 0.055) and an impaired habituation (SCR slope p = 0.064; EMG slope p = 0.005) in comparison to subjects with no or low DISS. In a subgroup analysis, high-level DISS patients with severe post-traumatic stress disorder (PTSD; n = 11) in comparison to high-level DISS patients without subsequent PTSD (n = 19) exhibited higher EMG amplitudes during all trials (repeated measures analysis of variance IF = 5.511, p = 0.026). The results demonstrate exaggerated startle responses in SCR and EMG measures - an abnormal defensive response to high-intensity stimuli which indicates a steady state of increased arousal. DISS patients without PTSD exhibited balanced autonomic responses to the startle trials. DISS may, therefore, unfold malignant properties only in combination with persistent physiological hyperarousability. Copyright (C) 2002 S. Karger AG, Basel

Clarification of Sugar Cane Juice (Saccharum Officinarum) Through the Use of National Cocoa Muclago (Theobroma Cacao L)

The investigation was carried out at 980 m.s.n. in the San Ramón compound of the El Corazón Parish, Pangua canton, Cotopaxi province, Ecuador. The variables to be evaluated in the sugar cane juice clarification process were the viscosity (20, 25 and 30 cp) and the concentration of Ragnar variety cocoa shell mucilage (0.75, 1.5, and 2.25%), to determine the spectral color and saturation in the sugarcane juice. 10 liters of juice were used in each experimental unit, taking the clarified syrup samples in amber bottles and refrigerating them until further analysis on the colorimeter was conducted. For the statistical evaluation of the results of the saturation percentage, normality tests were performed according to the Shapiro-Wilk statistic; applying the Friedman and Holm test of multiple comparisons, allowed to identify the combination of a1b2 (25 cp * 2.25%) as the best juice clarification treatment, and, managing to establish the descriptive data, thus: spectral color at 576 nm, saturation 46.91%; standard deviation 2.75; median 46.36%; variance 7.6 and a range of 5.43. Keywords: syrup, spectral, flocculant, cachaza. Resumen La investigación se realizó a 980 msnm en el recinto San Ramón de la Parroquia El Corazón, cantón Pangua, provincia Cotopaxi, Ecuador. Las variables a evaluar en el proceso de clarificación de jugo de caña de azúcar fueron la viscosidad (20, 25 y 30 cp) y la concentración de mucílago de cáscara de cacao variedad Ragnar (0,75%, 1,5% y 2,25%), para determinar el color espectral y de saturación en el jugo de caña de azúcar. En cada unidad experimental se usó 10 litros de jugo, tomando las muestras de jarabe clarificado en botellas tipo ámbar y refrigerándolas hasta posterior análisis en el colorímetro. Para la evaluación estadística de los resultados del porcentaje de saturación, se realizaron pruebas de normalidad según el estadístico de Shapiro-Wilk; aplicando el test de Friedman y Holm de comparaciones múltiples, permitieron identificar como mejor tratamiento de clarificación de jugo a la combinación a1b2 (25 cp * 2,25%), y, logrando establecer los datos descriptivos, así: color espectral en 576 nm, saturación 46,91%; desviación estándar 2,75; mediana 46,36%; varianza 7,6 y un rango de 5,43. Palabras clave: jarabe, espectral, floculante, cachaza

Fe, Caridad Y Educación: Una Mirada De Género Sobre Las Mujeres De La Asociación Del Sagrado Corazón De Jesús. Guadalajara De Buga (1873-1930)

Resumen El propósito de este escrito es visibilizar la participación de las mujeres en la Asociación del Sagrado Corazón de Jesús entre 1873 a 1930 en la ciudad de Guadalajara de Buga (Valle-Colombia). Así mismo, enunciar los discursos de género acerca del ideal de mujer católica, los roles y obras que debían ejercer dentro de la Asociación y la comunidad religiosa local. Summary The purpose of this paper is to highlight the participation of women in the Association of the Sacred Heart of Jesus between 1873-1930 in the city of Guadalajara de Buga (Valle-Colombia). Also, state the gender discourses about ideal Catholic woman, roles and works to be exercised within the Association and the religious community

Caracterización Molecular de la Diversidad Fúngica de los Bosques Llucud y Palictahua: Potencialidades en Control Biológico/Molecular Characterization of Diversity Fungic of the Llucud and Palictahua Forests: Potential in Biological Control

Dentro de los microorganismos más abundantes que se pueden encontrar en formaciones ecosistémicas naturales como los bosques andinos del Ecuador se encuentran los hongos microscópicos, los cuales desempeñan funciones cruciales en dichos ecosistemas. Por lo cual el objetivo de esta investigación fue caracterizar molecularmente la diversidad de hongos presentes en los bosques nativos Llucud y Palictahua, estableciendo sus potencialidades de uso en el control biológico de plagas y enfermedades que afectan a los cultivos agrícolas y cuyo control en su mayoría se lo realiza con plaguicidas químicos. Mediante secuenciación de próxima generación (NGS por sus siglas en inglés) de las muestras compuestas de suelo tomadas del horizonte “A” (rizósfera) de cada bosque, se identificaron 56 especies de hongos en Palictahua y 38 en Llucud, presentándose en ambos bosques un total de 6 hongos con importantes potencialidades para su uso en el control biológico, dentro de las cuales se encontraron: Brachyphoris oviparasitica (nematófago), Simplicillium (entomopatógeno y micoparásito), Hamamotoa lignophila (levadura con actividad Killer) en Llucud, y Metarhizium robertsii (entomopatógeno), Brachyphoris oviparasitica (nematófago) y Paraphaeosphaeria parmeliae (micoparásito) en Palictahua. El Bosque Palictahua presentó mayor diversidad de hongos que el bosque Llucud, sin embargo es importante cuidar ambos bosques, pues poseen una gran riqueza microbiana con un sinnúmero de posibilidades de uso en la medicina, industria, biotecnología y otros campos. Among the most abundant microorganisms that can be found in natural ecosystem formations such as the Andean forests of Ecuador are microscopic fungi, which play crucial roles in these ecosystems. So that the objective of this research was to molecularly characterize the diversity of fungi present in the native forests Llucud and Palictahua, establishing their potential for use in the biological control of pests and diseases that affect agricultural crops and whose control is mostly carried out with chemical pesticides. Through next-generation sequencing (NGS for its acronym in English) of compound samples of soil took from “A” horizon (rhizosphere). 56 species of fungi were identified in Palictahua and 38 in Llucud, presenting in both forests a total of 6 fungi with significant potential for use in biological control, among which were found: Brachyphoris oviparasitica (nematophagous), Simplicillium sp. (entomopathogen and mycoparasite), Hamamotoa lignophila (yeast with Killer activity) in Llucud, and Metarhizium robertsii (entomopathogen), Brachyphoris oviparasitica (nematophagous) and Paraphaeosphaeria parmeliae (mycoparasite) in Palictahua. The Palictahua forest presented greater diversity of fungi than the Llucud forest, however it is important to take care of both forests, since they have a great microbial richness with a myriad of possibilities of use in medicine, industry, biotechnology and other fields. Palabras clave: Biodiversidad, Microbiota, Plaguicidas. Keywords: Biodiversity, Microbiota, Pesticides

Joint route selection and split level management for 5G C-RAN

This work tackles the problem faced by network/infrastructure providers of jointly selecting routing and functional split level to satisfy requests from virtual mobile network operators (vMNOs). We build a novel system model that brings together all the involved elements and features, embracing split levels defined by the 3GPP and packet switch fronthaul network. To our best knowledge, this is the first work that provides a solution for multiple vMNO requests considering the two aforementioned sub-problems (i.e. split selection and routing). We use the model defined to formulate an optimization problem, which is characterized by the exponential size of its search space. We propose two heuristic approaches to address this problem: (1) a greedy scheme, and (2) an evolutionary algorithm, which is also improved with a specialized initialization. We conduct extensive experiments to assess the performance and behavior of the proposed methods, over varying network instances. When possible, we also perform comparisons with respect to the optimal solution and a well-known commercial solver. Our results indicate that the proposed techniques represent appropriate trade-offs between solution quality and execution time, and can serve complementary goals: the quality of the results yielded by our evolutionary method are better, but at the cost of longer execution times; in contrast, our greedy algorithm offers a reasonably appropriate performance, with an execution time that is notably lower. Our experiments show that it is possible to produce near-optimal results to the above complex problem through computationally efficient algorithmic solutions.This paper has been partially supported by the Secretary of Public Education of Mexico (SEP) and Cinvestav through research grant 262, and the National Council of Research and Technology (CONACYT) through grant ERANetLACFONCICYT No. 272278. Luis Diez and Ramon Agüero acknowledge the funding by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, MINECO-FEDER) by means of the project FIERCE: Future Internet Enabled Resilient smart CitiEs (RTI2018-093475-AI00)

Pathogenicity of Entomopathogenic Fungi on the Weevil of the Andes (Premnotrypes vorax Hustache) of the Potato (Solanum tuberosum L.) in Chimborazo Province, Ecuador

From thirty native isolates of entomopathogenic fungi, which were obtained from corpses of larvae and adults of Andean weevil (Premnotrypes vorax Hustache); two fungi with entomopathogenic characteristics were selected through laboratory tests, which will be used in a program of integrated management of this pest in the Ecuadorian inter-Andean region. The pathogenicity of the 30 isolates was determined by the mortality that they caused in larvae and adults and it was expressed in percentage; for this, a complete randomized design (CRD) was used. The LC50 and TL50 were determined by Probit analysis. The two selected isolates corresponded to: Metarhizium anisopliae (Metschnikoff 1879) Sorokin 1883 (A13) and  Beauveria bassiana (Bals.-Criv.) Vuill. 1912 (A21), which proved to be the best, because they caused the highest mortality in larvae of the fourth instar and adults of P. vorax. The Probit analysis showed that LC50 for A21 isolate (B. bassiana) in fourth instar larvae was obtained with a concentration of 1,75x109 spores/ml and 1,08x109 spores/ml for adults. Instead for A13 isolate (M. anisopliae), the LC50 was obtained with a concentration of 1,65x109 spores/ml for larvae and 2,42x109 spores/ml for adults. The LT50 for the selected isolates at the indicated concentrations, was 4,84 and 4,32 days for larvae with A13 and A21 isolates respectively, while, for adults, the shortest time was obtained with A21 isolate in 4.36 days, compared with A13 isolate, that delayed 20,70 days. The larval stage of P. vorax was the most susceptible to A13 isolate, on the other hand, larvae and adults were equally susceptible to A21 isolate at the indicated concentrations. According to the results obtained, the two selected isolates can be used as an alternative to the use of conventional agrochemicals, which will contribute to a more ecological production

Urbanisation is associated with prevalence of childhood asthma in diverse, small rural communities in Ecuador

BACKGROUND: Studies conducted in transitional communities from Africa and Asia have pointed to the process of urbanisation as being responsible for the increase in asthma prevalence in developing regions. In Latin America, there are few published data available on the potential impact of urbanisation on asthma prevalence. The aim of the present study was to explore how the process of urbanisation may explain differences in asthma prevalence in transitional communities in north-eastern Ecuador. METHODOLOGY/PRINCIPAL FINDINGS: An ecological study was conducted in 59 communities in Esmeraldas Province, Ecuador. Indicators of urbanisation were grouped into three indices representing the processes associated with urbanisation: socioeconomic, lifestyle and urban infrastructure. Categorical principal components analysis was used to generate scores for each index and a fourth index--a summary urbanisation index--was derived from the most representative variables in each of the three indices. The authors analysed the associations between community asthma prevalence and the indices, as well as with each indicator variable of every group. The overall prevalence of asthma was 10.1% (range 0-31.4% between communities). Three of the four indices presented significant associations with community asthma prevalence: socioeconomic (r = 0.295, p = 0.023), lifestyle (r = 0.342, p = 0.008) and summary urbanisation index (r = 0.355, p = 0.006). Variables reflecting better socioeconomic status and a more urban lifestyle were associated with greater asthma prevalence. CONCLUSIONS: These data provide evidence that the prevalence of asthma increases with increasing levels of urbanisation in transitional communities, and factors associated with greater socioeconomic level and changes towards a more urban lifestyle may be particularly important

Tipification methods and molecular epidemiology of staphylocuccus aureus with methicillin resistance

El interés actual del estudio de Staphylococcus aureus deriva de su elevada frecuencia de cepas resistentes a los antibióticos que causa frecuentes brotes de infección, especialmente, el S. aureus con resistencia a meticilina (SARM). El objetivo de esta revisión fue estudiar la estructura genética poblacional y el origen de los aislamientos de SARM. La tipificación del cassette cromosómico mec estafilocócico es el método más importante para identificar y definir la naturaleza clonal del S. aureus con resistencia a meticilina. Los estudios de epidemiología molecular evidencian un patrón de diseminación de unas pocas cepas que son las responsables del importante problema mundial. Existe el predominio de clones pandémicos de SARM asociado a infecciones hospitalarias (SARM-AH), que ha han sido reemplazados en la actualidad por clones de origen comunitario (SARM-AC). En Colombia, predomina el clon pediátrico y el chileno entre los aislamientos hospitalarios. Sin embargo, en la actualidad una variante del clon comunitario USA300 prevalece en las infecciones adquiridas en la comunidad y en el hospital, desplazando los clones hospitalarios como ocurre en el resto de mundo. El entendimiento de la epidemiología y clonalidad de las infecciones por S. aureus tiene importantes implicaciones en el control de la emergencia de cepas con multirresistencia y el esparcimiento de clones resistentes y sensibles a meticilina.Recent interest in the study of Staphylococcus aureus derives from the high frequency of antibiotic-resistant strains that cause frequent outbreaks of infection, especially Methicillinresistant S. aureus (MRSA). The objective of this review was to study the population genetic structure and the origin of MRSA isolation. Classification of staphylococcal cassette chromosomemec (SCCmec) is the most important method to identify and define the S. aureus methicillin-resistant clonal nature. Molecular epidemiologic studies have demonstrated dissemination patterns of few strains which are responsible for the important worldwide problem. There is a predominance of pandemic clones of MRSA associated to hospital-acquired infections (HA-MRSA) which has been replaced today by community-acquired strains (CA-MRSA). In Colombia, the pediatric clone and the Chilean clone predominate between hospital isolations. However, currently, there is a variant community clone USA300 prevailing in infections acquired in the community and in the hospital, displacing HA-MRSA as it happens in the rest of world. Understanding the epidemiology and clonality of S. aureus infections has important implications for future efforts to control of the emergence of multidrug-resistant strains and the spread of clones resistant and sensible to methicillin