A C0 interior penalty method for 4th order PDE's

Fourth order Partial Differential Equations (PDE's) arise in many different physic's fields. As an example, the research group for Mathematical and Computational Modeling at UPC LaCàN is studying flexoelectricity, a very promising field which aims to replace some of the uses of piezoelectric materials, and whose equations involve 4th order derivatives. This work provides a method to solve these 4th order PDE's using the Finite Element Method (FEM) with C0 elements, which provides many advantages with respect to other methods that involve using C1 elements or decoupling the equation. The method is developed over the equations of the deformation of a Kirchoff plate, which is also a 4th order PDE. This method is then successfully validated with numerical experiments, both physical and artificial. An analysis of the convergence as well as the method's sensitivity to a newly added parameter is also provided. Due to the success of the method, LaCàN group will use this method to solve flexoelectricity's PDE's

Comparing Fixed and Adaptive Computation Time for Recurrent Neural Networks

Adaptive Computation Time for Recurrent Neural Networks (ACT) is one of the most promising architectures for variable computation. ACT adapts to the input sequence by being able to look at each sample more than once, and learn how many times it should do it. In this paper, we compare ACT to Repeat-RNN, a novel architecture based on repeating each sample a fixed number of times. We found surprising results, where Repeat-RNN performs as good as ACT in the selected tasks. Source code in TensorFlow and PyTorch is publicly available at https://imatge-upc.github.io/danifojo-2018-repeatrnn/Comment: Accepted as workshop paper at ICLR 201

Dispersion measuring techniques

A study of chromatic dispersion (CD) in optical fibers, its effects on signal propagation, the devices to compensate it and the methods for its characterization. We have presented the exper- imental setups for the most popular frequency domain methods for CD measurement, Peucheret and Modulation Phase Shift Method (MPSM), as well as for an advanced method with improved performance, the Asymmetric Mode and Bias Control method (AMBC), whose theoretical basis have also been described. Experimental measures of the D parameter of CD for both 75km of standard single-mode fiber and a Dispersion Compensating Fiber Bragg Grating (DC-FBG) with all 3 methods have shown good agreement.2016/201

Constructivism in Choral Music Education: Supplemental Activities for the Traditional Choral Ensemble

Constructivism in music education can help teachers and students alike better their educational experience by working as a collaborative team. In the choral classroom, constructivist teaching establishes the teacher as the facilitator of learning rather than the “teacher as conductor.” Teachers help foster the musical-thinking of the ensemble. Students learn and retain information when teachers can support learners’ understanding of musical ideas and work within the student’s zone of proximal development. Through the use of teacher-guided questioning, cognitive apprenticeship, informal music-making, CMP, problem-solving, and Understanding by Design, students become active participants. Included are supplemental activities for the traditional choir classroom that give a sense of how to provide meaningful lessons to students through a constructivist lens. Each activity is objective-based, working from what the students will know or be able to do by the end of the activity, to how to foster the learning in a way that builds past experiences into new experiences

Can the endogenous nature of financial capitalism explain the recent dynamics for inequality?: a brief study on top-income households

Economic inequality and asymmetric income growth has long been a fierce battleground for opposite theoretical beliefs. In a context of a post-crisis scenario, as the one we live today, it matters above all a clear assessment whether the changes in modern capitalism into a financial-led type, is responsible for widening the gap among the richest and the poorest. Setting this goal in mind, an empirical study was conducted for forty-one countries during thirty-six years accessing the inequality via the income held by top ladder households: Top One Percent (TOP1) and Top Ten Percent (TOP10). The conclusions redrawn point for dissimilar behavioral dynamics between the incomes held by TOP1 and TOP10. Economies characterized by less reliance on global trade, higher percent of rural population, acuter educational disparities and more consumption aversion tend to generate higher returns for the TOP1 solely. Accompanying this set-up it is also noticeable two curious phenomena: firstly, the tendency of enlargement of the "ultra rich" wealth in situations oh high unemployment and lower life expectancy and secondly the non dependence of TOP1 income from the contemporaneous evolution of GDP which induces the idea of a "protective shield" in adverse economic situations for the national elites.A desigualdade económica e o crescimento assimétrico do rendimento têm sido um campo de batalha feroz para teorias antagónicas. No contexto de um cenário pós-crise, como o que vivemos hoje, importa acima de tudo, um esclarecimento se as mudanças recentes no capitalismo moderno são responsáveis por aumentar a diferença entre ricos e pobres. Tendo em vista este objetivo, num estudo empírico foi conduzida a modelização da evolução da desigualdade através do rendimento dos agregados familiares superiores: top um por cento (TOP1) e top dez por cento (TOP10). As conclusões obtidas apontam para uma dinâmica comportamental diferente entre os rendimentos do TOP1 e do TOP10: economias caracterizadas por uma menor dependência do comércio global, maior percentagem da população rural e disparidades educacionais assim como maior aversão ao consumo tendem a gerar maiores retornos para o TOP1 exclusivamente. Acompanhando esta realidade, verificam-se também dois fenómenos curiosos: primeiramente, a tendência para a ampliação da riqueza dos ultra ricos em situações de desemprego e menor esperança média de vida e, em segundo lugar, a não dependência do rendimento do TOP1 face à evolução contemporânea de PIB que induz a ideia de um "escudo protetor" para as elites nacionais aquando de situações económicas adversas

Condições Socioculturais e Econômicas que Contribuem para a Migração Ilegal no Distrito de Omo Nada, Zona Jimma, Estado Regional Nacional de Oromia, Sudoeste da Etiópia

Despite the fact that factors contributed to illegal migration (migrant smuggling and human trafficking) vary from context to context, there is scant of information for Omo Nada district, Jimma zone, Oromia National Regional State, South West Ethiopia. Thus, this study tried to explore the socio-cultural and economic factors that contributed to illegal migration of returnees to Omo Nada district. To this end, in-depth interviews, key informant interviews and focus group discussions were undertaken to collect qualitative data required for the study. The data was transcribed and analyzed thematically. Accordingly, the results of the findings showed that poverty, unemployment, lack of skills, influence of brokers/smugglers/traffickers, family pressure, religious and absence of legal means particularly for males are the major complex and reinforcing factors that gave rise to the illegal migration of the study participants.  The returnees’ subjective experiences of these factors and the meaning they gave to migration such as “means to escape poverty, alternative way to success and a key to unlock poverty” also motivated them to migrate.A pesar de que los factores que contribuyen a la migración ilegal (tráfico de migrantes y trata de personas) varían de un contexto a otro, hay poca información sobre el distrito de Omo Nada, la zona de Jimma, el Estado Regional Nacional de Oromia y el suroeste de Etiopía. Por lo tanto, este estudio trató de explorar los factores socio-culturales y económicos que contribuyeron a la migración ilegal de los retornados al distrito de Omo Nada. Con este fin, se realizaron entrevistas en profundidad, entrevistas con informantes clave y discusiones de grupos focales para recopilar datos cualitativos requeridos para el estudio. Los datos fueron transcritos y analizados temáticamente. En consecuencia, los resultados de los hallazgos mostraron que la pobreza, el desempleo, la falta de habilidades, la influencia de los corredores / traficantes / traficantes, la presión familiar, los religiosos y la ausencia de medios legales, especialmente para los hombres, son los principales factores complejos y de refuerzo que dieron origen a lo ilegal. Migración de los participantes del estudio. Las experiencias subjetivas de los retornados de estos factores y el significado que dieron a la migración como "medios para escapar de la pobreza, una forma alternativa de éxito y una clave para desbloquear la pobreza" también los motivaron a migrar.Apesar do fato de que fatores contribuidores para a migração ilegal (contrabando de migrantes e tráfico de seres humanos) variam de contexto para contexto, há pouca informação sobre o distrito de Omo Nada, zona de Jimma, Estado Regional Nacional de Oromia, Sudoeste da Etiópia. Assim, este estudo tentou explorar os fatores socioculturais e econômicos que contribuíram para a migração ilegal de retornados para o distrito de Omo Nada. Para este fim, foram realizadas entrevistas em profundidade, entrevistas com informantes-chave e discussões em grupo para coletar dados qualitativos necessários para o estudo. Os dados foram transcritos e analisados por temas. Assim, a análise dos resultados mostra que a pobreza, desemprego, falta de habilidades, influência de corretores/contrabandistas/traficantes, pressão familiar, religiosas e ausência de meios legais, particularmente para os homens, são os principais fatores complexos e reforçadores que deram origem à migração ilegal dos participantes do estudo. As experiências subjetivas dos retornados desses fatores e o significado que deram à migração, como “meios para escapar da pobreza, caminho alternativo para o sucesso e uma chave para liberar a pobreza”, também os motivaram a migrar

Experiências de Migração Ilegal de Retornados para o Distrito de Omo Nada, Zona Jimma, Estado Regional Nacional de Oromia, Sudoeste da Etiópia

Despite the fact that the illegal migration experiences of the returnees are important to design effective programs to reintegrate them into the community, there is scanty of information for the returnees to Omo Nada district.  The purpose of this study is to investigate the physical, economic and social abuse and exploitation faced by the returnees en route and in the place of destination. To this end, in-depth interviews, key informant interviews and focus group discussions were undertaken to collect qualitative data required for the study. The data was transcribed and analyzed thematically.  The results of the findings showed that the migrants were physically exhausted en route with hunger and thirst, subjected to physical abuse such as insults, beating, slapping, kicking, and bodily burn from the smugglers.  Injuries inflicted included bodily wounds, broken limbs and ribs. In addition to the physical abuse, the smugglers and traffickers robbed, and exploited migrants economically charging them for extra services at different transit points. This in turn made the migrants ended in debt bondage. Women became subject to sexual abuse by smugglers and by employers. The abuse continued in the country of destination by employers themselves. Economic exploitation took the form of long working hours with little rest, difficult workloads, reduced pay or wages withheld altogether. Punishment was particularly harsh for those with few or no skills. In addition, the situation deprived the study participants from getting sufficient or healthy food and theircommunication with their families left behind in the home country was restricted.  Women, usually domestic workers, had been subject to sexual abuse by employers and their families.A pesar del hecho de que las experiencias de migración ilegal de los retornados son importantes para diseñar programas efectivos para reintegrarlos a la comunidad, existe poca información para los retornados al distrito de Omo Nada. El propósito de este estudio es investigar el abuso físico, económico y social y la explotación que enfrentan los retornados en el camino y en el lugar de destino. Con este fin, se llevaron a cabo entrevistas en profundidad, entrevistas con informantes clave y grupos de discusión para recopilar datos cualitativos necesarios para el estudio. Los datos fueron transcritos y analizados temáticamente. Los resultados de los hallazgos mostraron que los migrantes estaban físicamente exhaustos en el camino con hambre y sed, sometidos a abusos físicos como insultos, golpes, bofetadas, patadas y quemaduras corporales por parte de los traficantes. Las lesiones infligidas incluyeron heridas corporales, extremidades y costillas rotas. Además del abuso físico, los traficantes y traficantes robaron y explotaron a los migrantes que les cobran económicamente por servicios adicionales en diferentes puntos de tránsito. Esto a su vez hizo que los migrantes terminaran en la servidumbre por deudas. Las mujeres fueron objeto de abuso sexual por parte de contrabandistas y empleadores. El abuso continuó en el país de destino por parte de los propios empleadores. La explotación económica tomó la forma de largas horas de trabajo con poco descanso, cargas de trabajo difíciles, salarios reducidos o salarios retenidos por completo. El castigo fue particularmente duro para aquellos con pocas o ninguna habilidad. Además, la situación privó a los participantes del estudio de obtener alimentos suficientes o saludables y se restringió su comunicación con sus familias que quedaron en el país de origen. Las mujeres, generalmente trabajadoras domésticas, habían sido objeto de abuso sexual por parte de los empleadores y sus familias.Apesar do fato de que as experiências de migração ilegal dos retornados são importantes para projetar programas efetivos para reintegrá-los à comunidade, há escassa informação para os retornados ao distrito de Omo Nada. O objetivo deste estudo é investigar o abuso e a exploração física, econômica e social enfrentados pelos retornados em trânsito e no local de destino. Para este fim, entrevistas em profundidade, entrevistas com informantes-chave e discussões em grupo foram realizadas para coletar dados qualitativos necessários para o estudo. Os dados foram transcritos e analisados por temas. Os resultados das descobertas mostraram que os migrantes estavam fisicamente exaustos no caminho com fome e sede, sujeitos a abusos físicos como insultos, espancamentos, tapa, chutes e queimaduras corporais dos contrabandistas. Lesões infligidas incluíam feridas corporais, membros quebrados e costelas. Além do abuso físico, os contrabandistas e traficantes roubavam e exploravam os migrantes economicamente, cobrando-os por serviços extras em diferentes pontos de trânsito. Isso, por sua vez, fez com que os migrantes terminassem em servidão por dívida. As mulheres ficaram sujeitas a abuso sexual por contrabandistas e empregadores. O abuso continuou no país de destino pelos próprios empregadores. A exploração econômica assumiu a forma de longas jornadas de trabalho com pouco descanso, cargas de trabalho difíceis, salários reduzidos ou salários totalmente retidos. A punição foi particularmente dura para aqueles com pouca ou nenhuma habilidade. Além disso, a situação privou os participantes do estudo de obter alimentos suficientes ou saudáveis, e sua comunicação com as famílias deixadas no país de origem foi restrita. As mulheres, geralmente domésticas, foram vítimas de abuso sexual por empregadores e suas famílias

Comparing fixed and adaptive computation time for recurrent neural networks

Deep networks commonly perform better than shallow ones, but allocating the proper amount of computation for each particular input sample remains an open problem. This issue is particularly challenging in sequential tasks, where the required complexity may vary for different tokens in the input sequence. Adaptive Computation Time (ACT) was proposed as a method for dynamically adapting the computation at each step for Recurrent Neural Networks (RNN). ACT introduces two main modifications to the regular RNN formulation: (1) more than one RNN steps may be executed between an input sample is fed to the layer and and this layer generates an output, and (2) this number of steps is dynamically predicted depending on the input token and the hidden state of the network. In our work, we aim at gaining intuition about the contribution of these two factors to the overall performance boost observed when augmenting RNNs with ACT. We design a new baseline, Repeat-RNN, which performs a constant number of RNN state updates larger than one before generating an output. Surprisingly, such uniform distribution of the computational resources matches the performance of ACT in the studied tasks. We hope that this finding motivates new research efforts towards designing RNN architectures that are able to dynamically allocate computational resources. TL;DR: Comparison of Adaptive Computation Time with Fixed computation time for RNN's gives surprising resultsPostprint (author's final draft

Complementation of two mutant p53: Implications for loss of heterozygosity in cancer

AbstractRemarkably, a cancer cell rarely possesses two mutant p53 proteins. Instead, mutation of one allele is usually associated with loss of the second p53 allele. Why do not two mutant p53 co-exist? We hypothesize that two different p53 may complement each other, when expressed at equal levels. By titrating trans-deficient and DNA-binding-deficient p53 in cells with mutant p53 and by co-transfecting distinct mutant p53 in p53-null cells, we demonstrated activation of p53-dependent transcription. We suggest that, due to complementation of two mutant p53, cancer cells need to delete the second p53 allele rather than mutate it

Visible-emitting Cu(i) complexes with N-functionalized benzotriazole-based ligands

Luminescent mono- and dinuclear cationic heteroleptic Cu(I) complexes [Cu(N∧N′)(P)2]+, [Cu(N∧N′)(P∧P)]+ or [Cu2(N∧N′)2(μ-P∧P)2]2+ containing bidentate N-donor ligands (N∧N′) with benzotriazole, pyridine, pyrimidine or substituted triazine moieties in combination with mono- (P) and bidentate (P∧P) phosphines were synthesized and characterized. Eight single-crystal X-ray diffraction structures were obtained and showed marked distortions from the ideal tetrahedral geometry around Cu(I). Cyclic voltammetry on selected complexes showed reduction processes around −2 V vs. ferrocene/ferrocenium and irreversible oxidation close to 1 V. The long-wavelength absorptions were observed in the range of 350 to 450 nm and attributed to MLCT transitions. Upon excitation with near-UV and violet light, the complexes exhibited emissions from bright yellow (max 538 nm) to red (max 637 nm). Emission maxima, luminescence lifetimes and photoluminescence quantum yields that reach up to 0.92 on powder samples resulted in strong dependence on the choice of the coordinated ligands, the acceptor character of the N∧N′ ligands in particular. DFT calculations confirmed the electrochemical and photophysical outcomes and strongly suggested that the emission has a metal-to-ligand charge transfer (MLCT) nature, with intersystem crossing affording triplet emitting states