Symbolic Logic meets Machine Learning: A Brief Survey in Infinite Domains

The tension between deduction and induction is perhaps the most fundamental issue in areas such as philosophy, cognition and artificial intelligence (AI). The deduction camp concerns itself with questions about the expressiveness of formal languages for capturing knowledge about the world, together with proof systems for reasoning from such knowledge bases. The learning camp attempts to generalize from examples about partial descriptions about the world. In AI, historically, these camps have loosely divided the development of the field, but advances in cross-over areas such as statistical relational learning, neuro-symbolic systems, and high-level control have illustrated that the dichotomy is not very constructive, and perhaps even ill-formed. In this article, we survey work that provides further evidence for the connections between logic and learning. Our narrative is structured in terms of three strands: logic versus learning, machine learning for logic, and logic for machine learning, but naturally, there is considerable overlap. We place an emphasis on the following "sore" point: there is a common misconception that logic is for discrete properties, whereas probability theory and machine learning, more generally, is for continuous properties. We report on results that challenge this view on the limitations of logic, and expose the role that logic can play for learning in infinite domains

c-Myc Regulates Self-Renewal in Bronchoalveolar Stem Cells

BACKGROUND: Bronchoalveolar stem cells (BASCs) located in the bronchoalveolar duct junction are thought to regenerate both bronchiolar and alveolar epithelium during homeostatic turnover and in response to injury. The mechanisms directing self-renewal in BASCs are poorly understood. METHODS: BASCs (Sca-1(+), CD34(+), CD31(-) and, CD45(-)) were isolated from adult mouse lung using FACS, and their capacity for self-renewal and differentiation were demonstrated by immunostaining. A transcription factor network of 53 genes required for pluripotency in embryonic stem cells was assessed in BASCs, Kras-initiated lung tumor tissue, and lung organogenesis by real-time PCR. c-Myc was knocked down in BASCs by infection with c-Myc shRNA lentivirus. Comprehensive miRNA and mRNA profiling for BASCs was performed, and significant miRNAs and mRNAs potentially regulated by c-Myc were identified. We explored a c-Myc regulatory network in BASCs using a number of statistical and computational approaches through two different strategies; 1) c-Myc/Max binding sites within individual gene promoters, and 2) miRNA-regulated target genes. RESULTS: c-Myc expression was upregulated in BASCs and downregulated over the time course of lung organogenesis in vivo. The depletion of c-Myc in BASCs resulted in decreased proliferation and cell death. Multiple mRNAs and miRNAs were dynamically regulated in c-Myc depleted BASCs. Among a total of 250 dynamically regulated genes in c-Myc depleted BASCs, 57 genes were identified as potential targets of miRNAs through miRBase and TargetScan-based computational mapping. A further 88 genes were identified as potential downstream targets through their c-Myc binding motif. CONCLUSION: c-Myc plays a critical role in maintaining the self-renewal capacity of lung bronchoalveolar stem cells through a combination of miRNA and transcription factor regulatory networks

Prevalência de deficiência auditiva referida e fatores associados em uma população de idosos da cidade de Manaus: um estudo de base populacional

RESUMO: Objetivo: estimar a prevalência de deficiência auditiva referida e fatores associados em idosos da cidade de Manaus. Métodos: realizou-se um estudo seccional de base populacional em 646 sujeitos com 60 anos ou mais entrevistados durante 2013. A amostra foi obtida com o delineamento transversal, com amostragem por conglomerados, dois estágios de seleção e auto ponderada. Os dados foram analisados pelo teste Qui-quadrado e Regressão de Poisson. Resultados: prevalência de perda auditiva referida de 25,7%. Os fatores que se mantiveram significantemente associados após modelo multivariado foram: viver sozinho (RP= 1,34), dependência em Atividades Instrumentais de Vida Diária (RP=1,61), labirintite (RP=1,33), Mal de Parkinson (RP=2,02), dificuldade de compreensão (RP=1,69), deficiência visual (RP=1,94) e dificuldade de comunicação (RP=1,34). Os impactos na comunicação apontaram que a perda auditiva foi 68% maior entre em os indivíduos com dificuldade de fala em comparação aos que não referiram tal dificuldade, reforçando a limitação que a perda auditiva pode trazer à comunicação. Conclusão: a prevalência de perda auditiva entre idosos aponta para a necessidade de se conhecer a magnitude desse déficit para a saúde pública, e contribuir para a construção de estratégias de identificação dessas perdas, possibilitando a minimização desses efeitos neste grupo

Glassy state in Bacillus subtilis spore analyzed by differential scanning calorimetry

Thermal properties of dried spores of Bacillus subtilis, investigated by differential scanning calorimetry (DSC), were studied. A reversible heat capacity shift ascribable to glass\u2013rubber transition was observed at 90\u2013115 -C. The transition was found to be a pressure-inhibited volumeactivated event. The decoated spores and the extracted peptidoglycan material exhibited glass transition, suggesting that the cortex could be involved in the event. Furthermore, the glass transition was evident when spores were treated with strong acid, and when the isogenic strain PS578 was scanned, indicating that core integrity and core components are not involved in the occurrence of the event. These results suggest that in the dried B. subtilis spores an amorphous biomaterial, possibly the cortex peptidoglycan, is present as a glass

TN-Grid and gene@home project: volunteer computing for bioinformatics

The ability to reconstruct and find genes that belong or are connected to a gene regulatory network is of essential importance in biology, in order to understand how the biological processes of an organism work. The main limitation in performing gene network expansion is related to the huge amount of computations needed to discover new candidate genes. Given these premises we decided to adopt the BOINC platform that allows us to use the very powerful computational resources of the volunteers. We set up a BOINC server in which we developed a specific work generator that implements our gene network expansion algorithm. Furthermore, we developed an ad hoc version of the PC algorithm (PC++) able to run in the BOINC environment, on the client computers. We present and discuss some statistics and preliminary scientific results of the gene@home BOINC project, the first one hosted by the TN-Grid infrastructur

Uso de séries temporais na análise de vazão de água na represa de furnas Use of time series analysis for the water outflow at furnas dam

Com este trabalho teve-se como principal objetivo analisar o comportamento da série de vazão de água na barragem de Furnas, empregando análise de séries temporais e estudando o efeito de sazonalidade, tendência e intervenção. Para a análise, foram considerados modelos de séries temporais com e sem a presença de intervenção. Os dados referem-se à vazão (m³/s) da Barragem de Furnas - MG, coletada diariamente no período de janeiro de 1963 a dezembro de 1994. Foi realizada uma média mensal dos dados, em que cada média representa uma observação, num total de 372. Observou-se que a série de vazão fica bem ajustada utilizando modelos sazonais e a incorporação do parâmetro de intervenção forneceu informações complementares na análise.<br>This work aimed to fit time series models to the series of water outflow at Furnas Dam. We studied the effect of trend, seasonality and intervention factor in the analysis. Data were colleted daily from January of 1963 to December of 1994 at Furnas Dam. We considered Box & Jenkins models models with and without the intervention factor. We noted that the series of water outflow are fitted by SARIMA models and the intervention factor gave us more information