Applying the dynamics of evolution to achieve reliability in master-worker computing

We consider Internet-based master-worker task computations, such as SETI@home, where a master process sends tasks, across the Internet, to worker processes; workers execute and report back some result. However, these workers are not trustworthy, and it might be at their best interest to report incorrect results. In such master-worker computations, the behavior and the best interest of the workers might change over time. We model such computations using evolutionary dynamics, and we study the conditions under which the master can reliably obtain task results. In particular, we develop and analyze an algorithmic mechanism based on reinforcement learning to provide workers with the necessary incentives to eventually become truthful. Our analysis identifies the conditions under which truthful behavior can be ensured and bounds the expected convergence time to that behavior. The analysis is complemented with illustrative simulations.This work is supported by the Cyprus Research Promotion Foundation grant TΠE/ΠΛHPO/0609(BE)/05, the National Science Foundation (CCF-0937829, CCF-1114930), Comunidad de Madrid grants S2009TIC-1692 and MODELICO-CM, Spanish PRODIEVO and RESINEE grants and MICINN grant EC2011-29688-C02-01, and National Natural Science Foundation of China grant 61020106002.Publicad

Diferencias cualitativas en la forma en que niños y niñas utilizan la imaginación en tareas creativas

En esta comunicación abordamos un tema a menudo controvertido: las diferencias en creatividad en función del sexo de los sujetos. Este estudio fue llevado a cabo con una muestra compuesta por 1277 sujetos, 754 varones y 523 mujeres, 697 niños de entre 9 y 12 años y 580 adolescentes de 13 a 18 años. Para la evaluación de la creatividad se utilizó la Prueba de Imaginación Creativa PIC-N (niños) y PIC-J (adolescentes). Nuestros resultados mostraron que tanto las niñas como las adolescentes obtuvieron mejores puntuaciones en la mayor parte de los índices de creatividad que los niños y chicos de estas edades. Estas diferencias entre sexos fueron mayores en los niños más jóvenes. Estos resultados parecen indicar que existen importantes diferencias cualitativas, más que cuantitativas, en la forma en que niños y niñas utilizan la imaginación en tareas creativas. Consideramos que estas diferencias cualitativas pueden deberse en parte a diferencias biológicas en los ritmos de maduración cerebral de niños y niñas, pero fundamentalmente son debidas a diferencias en los estilos de aprendizaje, las expectativas, y la motivación en el desarrollo de niños y niñas.In this paper, we approach the relationship between two issues which stir up a wide controversy: gender and creativity. The investigation was conducted with a sample of 1277 subjects, 754 males and 523 females: 697 elementary students (9 to 12 years of age) and 580 adolescents (13 to 18 years of age). Our results indicate that in divergent thinking tests females of all ages obtained better results in almost all scores. Greater differences were found in younger children. These results seem to indicate that there are important qualitative, rather than quantitative, differences in the way boys and girls use their imagination in creativity tasks. We consider that these qualitative differences are probably due in part to genetic or biological factors, that might explain the difference between sexes in creative achievement in different domains. But mostly, we believe that these qualitative differences are also due to differences in learning styles, expectations, and motivations, in the development of boys and girls.peerReviewe

Achieving Reliability in Master-worker Computing via Evolutionary Dynamics

The proceeding at: 18th International Conference on Parallel and Distributed Computing, Euro-Par 2012), took place 2012, August 27-31, in Rhodes Island, Greece.This work considers Internet-based task computations in which a master process assigns tasks, over the Internet, to rational workers and collect their responses. The objective is for the master to obtain the correct task outcomes. For this purpose we formulate and study the dynamics of evolution of Internet-based master-worker computations through reinforcement learning.This work is supported by the Cyprus Research Promo-tion Foundation grant TΠE/ΠΛHPO/0609(BE)/05, NSF grants CCF-0937829, CCF-1114930, Comunidad de Madrid grant S2009TIC-1692, Spanish MOSAICO and RESINEE grants and MICINN grant TEC2011-29688-C02-01, and National Natural Science Foundation of China grant 61020106002.Publicad

Associations between Dark Triad and Ambivalent Sexism: Sex Differences among Adolescents

The Dark Triad traits (DT; Machiavellianism, psychopathy, and narcissism) have been repeatedly labeled as a constellation of traits that are characterized by a dishonest and self-focused approach to interpersonal relations. Personality psychologists suggest that these traits make some people more susceptible than others to intergroup bias, threat, and aggression. Thus, in order to delve into a psychological profile prone to accepting and justifying sexist attitudes, the aims of the current study were to analyze the presence of DT and sexist attitudes in a sample of 367 adolescents (Mage = 15.12, SD = 0.88; 50.1% males), find out the relationships that DT has with both hostile and benevolent sexism, and analyze the relevant differences between sexes in these relationships. The results indicated higher scores in DT and Ambivalent sexism for males. The correlations of Machiavellianism with psychopathy, and psychopathy with narcissism revealed significantly higher associations in males than females. The structural equation modeling of the bifactorial model, characterized by a global latent factor that encompasses the common characteristics of DT—along with the three specific factors of Machiavellianism, psychopathy, and narcissism—showed that the global latent factor of DT was related to both hostile and benevolent sexism in males and females. Singularly, narcissism was related to benevolent sexism in males, and psychopathy was related to hostile sexism in females. Finally, this research discusses the implications of these results on the implementation of positive models of interpersonal relationships in adolescence towards dating violence preventionThis research was funded by Ministry of Education, Culture and Sports of Spain under the program “Ayudas para la formación de profesorado universitario” (FPU17/02607)S

The action of obestatin in skeletal muscle repair: stem cell expansion, muscle growth, and microenvironment remodeling

The development of therapeutic strategies for skeletal muscle diseases, such as physical injuries and myopathies, depends on the knowledge of regulatory signals that control the myogenic process. The obestatin/GPR39 system operates as an autocrine signal in the regulation of skeletal myogenesis. Using a mouse model of skeletal muscle regeneration after injury and several cellular strategies, we explored the potential use of obestatin as a therapeutic agent for the treatment of trauma-induced muscle injuries. Our results evidenced that the overexpression of the preproghrelin, and thus obestatin, and GPR39 in skeletal muscle increased regeneration after muscle injury. More importantly, the intramuscular injection of obestatin significantly enhanced muscle regeneration by simulating satellite stem cell expansion as well as myofiber hypertrophy through a kinase hierarchy. Added to the myogenic action, the obestatin administration resulted in an increased expression of VEGF/VEGFR2 and the consequent microvascularization, with no effect on collagen deposition in skeletal muscle. Furthermore, the potential inhibition of myostatin during obestatin treatment might contribute to its myogenic action improving muscle growth and regeneration. Taken together, our data demonstrate successful improvement of muscle regeneration, indicating obestatin is a potential therapeutic agent for skeletal muscle injury and would benefit other myopathies related to muscle regeneration

Effectiveness of the mantente REAL program for preventing alcohol use in spanish adolescents

Mantente REAL is a school-based universal program to prevent drug use and other problematic behaviors specifically designed to be implemented in schools at the beginning of adolescence. This program, which is a culturally adapted version of the Keepin’ it REAL intervention, focuses on skills training for resisting social pressure to use drugs and improving psychosocial development. This study aims to evaluate the effectiveness of Mantente REAL on alcohol use in the Spanish context. The sample was composed of 755 adolescents from 12 state secondary schools in Spain, aged 11 to 15 (M = 12.24, SD = 0.56), 47.1% females. The 12 schools were randomly assigned to control and experimental groups, six to each condition. Pre-test and post-test questionnaires data were collected to evaluate the effectiveness of the program. The results indicated that a culturally adapted version of Mantente REAL was effective in preventing alcohol use among youth from northern and southern Spain. Students participating in the program demonstrated changes in the desired direction on alcohol frequency and intoxication episodes. Implications of these results regarding intervention programs aimed at preventing substance use in adolescence are discussed“Mantente REAL” es un programa universal que utiliza la escuela para prevenir el consumo de drogas y otras conductas problemáticas diseñado específicamente para ser implementado en las escuelas al comienzo de la adolescencia. Este programa, que es una versión culturalmente adaptada de la intervención Keepin’ it REAL, se centra en el entrenamiento de habilidades para resistir la presión social para consumir drogas y mejorar el desarrollo psicosocial. Este estudio tiene como objetivo evaluar la eficacia de “Mantente REAL” en el consumo de alcohol en el contexto español. La muestra estuvo compuesta por 755 adolescentes de 12 escuelas secundarias públicas en España, de 11 a 15 años (M = 12.24, DT = 0.56), el 47.1% mujeres. Las 12 escuelas fueron asignadas aleatoriamente a grupo control y experimental, seis en cada condición. Los datos se recopilaron a través de cuestionarios antes y después de la intervención para evaluar la eficacia del programa. Los resultados indicaron que la versión culturalmente adaptada de “Mantente REAL” fue eficaz para prevenir el consumo de alcohol entre los jóvenes del norte y sur de España. Los estudiantes que participaron en el programa demostraron cambios en la dirección deseada en la frecuencia del alcohol y los episodios de intoxicación. Se discuten las implicaciones de estos resultados con respecto a los programas de intervención destinados a prevenir el consumo de sustancias en la adolescenciaThis study was funded by the Global Center for Applied Health Research (Arizona State University) and supported by the Programa de Axudas á etapa posdoutoral da Xunta de Galicia (Consellería de Cultura, Educación e Ordenación Universitaria) and by FEDER/Ministerio de Ciencia, Innovación y Universidades – Agencia Estatal de Investigación (Grant PSI2015-65766-R) – under the Axuda para a consolidación e estruturación de unidades de investigación competitivas e outras accións de fomento nas universidades do SUG (GRC, 2018)S

Preclinical studies with glioblastoma brain organoid co-cultures show efficient 5-ALA photodynamic therapy

Abstract: Background: The high recurrence of glioblastoma (GB) that occurs adjacent to the resection cavity within two years of diagnosis urges an improvement of therapies oriented to GB local control. Photodynamic therapy (PDT) has been proposed to cleanse infiltrating tumor cells from parenchyma to ameliorate short long-term progression-free survival. We examined 5-aminolevulinic acid (5-ALA)- mediated PDT effects as therapeutical treatment and determined optimal conditions for PDT efficacy without causing phototoxic injury to the normal brain tissue. Methods: We used a platform of Glioma Initiation Cells (GICs) infiltrating cerebral organoids with two different glioblastoma cells, GIC7 and PG88. We measured GICs-5-ALA uptake and PDT/5-ALA activity in dose-response curves and the efficacy of the treatment by measuring proliferative activity and apoptosis. Results: 5-ALA (50 and 100  g/mL) was applied, and the release of protoporphyrin IX (PpIX) fluorescence measures demonstrated that the emission of PpIX increases progressively until its stabilization at 24 h. Moreover, decreased proliferation and increased apoptosis corroborated the effect of 5-ALA/PDT on cancer cells without altering normal cells. Conclusions: We provide evidence about the effectiveness of PDT to treat high proliferative GB cells in a complex in vitro system, which combines normal and cancer cells and is a useful tool to standardize new strategic therapies

Clonación de genotipos adultos y juveniles de Quercus suber y Q. ilex tolerantes a Phytophthora cinnamomi

El síndrome de “la seca” está generando desde hace décadas la pérdida de masas de Quercus mediterráneos provocando grandes pérdidas económicas y ecológicas. Por ello, en 2019 el subgrupo de “Mejora Genética y Fisiología” del Grupo de Trabajo sobre Seca del Ministerio para la Transición Ecológica y el Reto Demográfico impulsó el Programa Nacional para la Conservación y Mejora de Recursos Genéticos de Encina y Alcornoque. Este programa contempla la clonación y la conservación de material tolerante a Phytophthora cinnamomi y/o sequía, seleccionado en anteriores proyectos de investigación. Aplicando técnicas de cultivo in vitro, embriogénesis somática y proliferación de yemas axilares, se pretende clonar una selección de individuos dentro de las progenies más tolerantes, y los mejores genotipos adultos evaluados a través de esas progenies. Las hojas son el explanto elegido para inducir embriones somáticos en material juvenil y adulto de alcornoque; en material de encina adulto el explanto inicial es el tegumento del embrión inmaduro. Las líneas embriogénicas generadas han sido conservadas a largo plazo mediante su crioconservación (almacenamiento en nitrógeno líquido). La proliferación de yemas axilares se emplea para clonar genotipos juveniles de ambas especies. La clonación del material permitirá disponer de copias suficientes que permitan la evaluación de su tolerancia en ensayos de campo

Crowd computing as a cooperation problem: an evolutionary approach

Cooperation is one of the socio-economic issues that has received more attention from the physics community. The problem has been mostly considered by studying games such as the Prisoner's Dilemma or the Public Goods Game. Here, we take a step forward by studying cooperation in the context of crowd computing. We introduce a model loosely based on Principal-agent theory in which people (workers) contribute to the solution of a distributed problem by computing answers and reporting to the problem proposer (master). To go beyond classical approaches involving the concept of Nash equilibrium, we work on an evolutionary framework in which both the master and the workers update their behavior through reinforcement learning. Using a Markov chain approach, we show theoretically that under certain----not very restrictive-conditions, the master can ensure the reliability of the answer resulting of the process. Then, we study the model by numerical simulations, finding that convergence, meaning that the system reaches a point in which it always produces reliable answers, may in general be much faster than the upper bounds given by the theoretical calculation. We also discuss the effects of the master's level of tolerance to defectors, about which the theory does not provide information. The discussion shows that the system works even with very large tolerances. We conclude with a discussion of our results and possible directions to carry this research further.This work is supported by the Cyprus Research Promotion Foundation grant TE/HPO/0609(BE)/05, the National Science Foundation (CCF-0937829, CCF-1114930), Comunidad de Madrid grant S2009TIC-1692 and MODELICO-CM, Spanish MOSAICO, PRODIEVO and RESINEE grants and MICINN grant TEC2011-29688-C02-01, and National Natural Science Foundation of China grant 61020106002.Publicad