Behavior of early warnings near the critical temperature in the two-dimensional Ising model

Among the properties that are common to complex systems, the presence of critical thresholds in the dynamics of the system is one of the most important. Recently, there has been interest in the universalities that occur in the behavior of systems near critical points. These universal properties make it possible to estimate how far a system is from a critical threshold. Several early-warning signals have been reported in time series representing systems near catastrophic shifts. The proper understanding of these early-warnings may allow the prediction and perhaps control of these dramatic shifts in a wide variety of systems. In this paper we analyze this universal behavior for a system that is a paradigm of phase transitions, the Ising model. We study the behavior of the early-warning signals and the way the temporal correlations of the system increase when the system is near the critical point.Comment: 20 pages, 8 figures, Submitted to PLOS ONE on Oct. 20th 2014. PONE-D-14-4718

Reaction-noise induced homochirality

Starting from the chemical master equation, we employ field theoretic techniques to derive Langevin-type equations that exactly describe the stochastic dynamics of the Frank chiral amplification model with spatial diffusion. The intrinsic multiplicative noise properties are completely and rigorously derived by this procedure. We carry out numerical simulations in two spatial dimensions. When the inherent spatio-temporal fluctuations are properly included, then complete chiral amplification results from a purely racemic initial configuration. Phase separation can also arise in which the enantiomers coexist in spatially segregated domains separated by a sharp racemic interface or boundary.Comment: 11 pages, 3 figures in colo

Evaluación de dos métodos de propagación asexual en dos clones de banano (Musa paradisiaca) con mayor eficacia en el valle del Chira - Piura, 2016.

El propósito del presente trabajo de investigación, fue evaluar dos métodos de propagación asexual en dos clones de banano (Musa paradisiaca) con mayor eficacia en el valle del Chira - Piura, 2016; en un área experimental de 76,5 m2. La investigación duró 4 meses, iniciando el 8 de julio del 2017 y finalizando el 6 de octubre del mismo año. Se utilizó el diseño experimental de Bloque Completo al Azar (BCA) con arreglo Factorial de 2 x 2, con cuatro tratamientos y cuatro repeticiones; T1: Ablación + Valery, T2: Ablación + Williams, T3: División + Valery y T4: División + Williams. Al finalizar este trabajo de investigación se concluyó que; el método más adecuado para la propagación de banano, es el método de ablación de la yema apical con 25,00 días en el clon Valery y 26,69 días en el clon Williams para el menor tiempo de emergencia, que presenta una significancia estadística con respecto al método de división de cormos de banano. Con respecto a los clones estudiados no se presentaron estadísticamente diferencias significativas siendo indiferente el uso de cualquiera de ellos y con respecto al diámetro de pseudotallos en las plantas de banano existe una diferencia estadística significativa entre los tratamientos, siendo el T2 (Ablación + Williams) con 2,03 cm de diámetro estadísticamente superior con respecto a los demás tratamientos, los resultados demuestran que T1, T3 y T4 son estadísticamente similares entre sí. Con estos resultados el productor bananero tendrá nuevas posibilidades para la multiplicación y propagación de bananos.Tesi

Environmental tipping points for sperm motility, fertilization, and embryonic development in the crown-of-thorns starfish

For broadcast spawning invertebrates such as the crown-of-thorns starfish, early life history stages (from spawning to settlement) may be exposed to a wide range of environmental conditions, and could have a major bearing on reproductive success and population replenishment. Arrested development in response to multiple environmental stressors at the earliest stages can be used to define lower and upper limits for normal development. Here, we compared sperm swimming speeds and proportion of motile sperm and rates of fertilization and early development under a range of environmental variables (temperature: 20–36 oC, salinity: 20–34 psu, and pH: 7.4–8.2) to identify environmental tipping points and thresholds for reproductive success. We also tested the effects of water-soluble compounds, derived from eggs, on sperm activity. Our results demonstrate that gametes, fertilization, and embryonic development are robust to a wide range of temperature, salinity, and pH levels that are outside the range found at the geographical limits of adult distribution and can tolerate environmental conditions that exceed expected anomalies as a result of climate change. Water-soluble compounds derived from eggs also enhanced sperm activity, particularly in environmental conditions where sperm motility was initially limited. These findings suggest that fertilization and embryonic development of crown-of-thorns starfish are tolerant to a wide range of environmental conditions, though environmental constraints on recruitment success may occur at later ontogenic stages

Price Metric for the Improvement of Accommodation Service Offers in Sucre- San Vicente Tourist Destination

Purpose:  Present a strategic study of accommodation prices based on a price metric at the level of lodging activity to improve offers of the lodging service in tourist destination Sucre-San Vicente.   Theoretical framework:  The recent state of the art literature has shown the growing need for hotel companies to obtain a sustainable competitive advantage. Due to this need, this study on lodging costs is of vital importance to determine cost standards at the level of lodging activity in Ecuador.   Design/Methodology/Approach:  The study was carried out based on the database of the Decentralized Autonomous Governments (cadastre) of the cantons Sucre and San Vicente and under the supervision of the Uleam Tourism Observatory to examine the accommodation activity and its cost for lodging.   Findings:  Among the main successes there is a close alignment between the prices offered and the prices requested by the hotels, indicating an adequate adaptation to the demand offered and the prices requested by the hotels, indicating an appropriate adaptation to the demand.   Research, Practical & Social implications: The findings support informed decision-making in hotel pricing management, benefiting both hotels by maintaining competitiveness and travellers by planning their accommodation budgets with greater confidence.   Originality/Value:  This study adds value by highlighting price alignment and a conservative rate-setting strategy in the hotel industry of Sucre-San Vicente, offering useful insights for price management and customer satisfaction

Heterogeneous cancer-associated fibroblast population potentiates neuroendocrine differentiation and castrate resistance in a CD105-dependent manner.

Heterogeneous prostatic carcinoma-associated fibroblasts (CAF) contribute to tumor progression and resistance to androgen signaling deprivation therapy (ADT). CAF subjected to extended passaging, compared to low passage CAF, were found to lose tumor expansion potential and heterogeneity. Cell surface endoglin (CD105), known to be expressed on proliferative endothelia and mesenchymal stem cells, was diminished in high passage CAF. RNA-sequencing revealed SFRP1 to be distinctly expressed by tumor-inductive CAF, which was further demonstrated to occur in a CD105-dependent manner. Moreover, ADT resulted in further expansion of the CD105+ fibroblastic population and downstream SFRP1 in 3-dimensional cultures and patient-derived xenograft tissues. In patients, CD105+ fibroblasts were found to circumscribe epithelia with neuroendocrine differentiation. CAF-derived SFRP1, driven by CD105 signaling, was necessary and sufficient to induce prostate cancer neuroendocrine differentiation in a paracrine manner. A partially humanized CD105 neutralizing antibody, TRC105, inhibited fibroblastic SFRP1 expression and epithelial neuroendocrine differentiation. In a novel synthetic lethality paradigm, we found that simultaneously targeting the epithelia and its microenvironment with ADT and TRC105, respectively, reduced castrate-resistant tumor progression, in a model where either ADT or TRC105 alone had little effect

Utilization of Blended Learning to Teach Preclinical Endodontics

Blended learning (BL) is the integration of classroom learning with an online environment. The purpose of this study was to determine whether dental students who experienced BL in a preclinical endodontic course demonstrated better manual skills, conceptual knowledge, and learning experience compared to those experiencing traditional learning. All eighty-one students (100 percent) in a preclinical endodontics course agreed to participate and were assigned to either the traditional or BL group. A root canal procedure was used to determine the level of manual skills gained by each group. Pre- and post-intervention quizzes were given to all students to evaluate conceptual knowledge gained, and the students' perspectives on the methods were evaluated with a survey. The BL group scored better than the traditional group on the manual skills exercise at a statistically significant level (p=0.0067). There were no differences in the post-intervention quiz scores between the two groups, and the students' opinions were positive regarding BL. With BL, the students were able to learn and demonstrate dental skills at a high level

Plan De Gestión Municipal Participativa Para Optimizar La Ejecución Del Gasto Público Del FONCOMÚN En La Municipalidad Distrital Las Pirias Jaén 2018

El presente estudio se origina a partir de la problemática relación a da con la ejecución del gasto público del FONCOMUN en la municipalidad distrital de la Pirias, donde gran parte de losrecursoseconómicosnosonutilizadosconuncriteriotécnico,nirespondena los planes de desarrollo concertado, donde las decisiones de inversión se toman de manera unilateral a nivel de autoridades municipales, dejando de lado la participación de la comunidad organizada en las decisiones municipales ,razón por la cual es que se plantea el presente trabajo de investigación cuyo objetivo general es: Proponer un plan de gestión participativa para optimizar la ejecución del gasto público del FONCOMUN en la Municipalidad distrital de las Pirias de Jaén–2018.. El estudio se enmarca dentro de una investigación descriptiva propositiva que parte del diagnóstico de la problemática en la ejecución del gasto público del FONCOMUN de la municipalidad distrital de la Pirias Jaen, siendo los informantes12 trabajadores del área de rentas a quienes se les aplicó un cuestionario cuyos datos fueron procesados y presentados en tablas y figuras haciendo uso de la estadística descriptiva. Luego de procesar la información y discutir los mismos, se procedió a elaborar lapropuestaconsistenteenplandegestiónmunicipalparticipativaparaoptimizarlaejecucióndel gasto público del FONCOMUN, el mismo que fue validado posteriormente mediante criterio de experto