Compressing Binary Decision Diagrams

The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1-2 bits per node. Empirical results for our compression technique are presented, including comparisons with previously introduced techniques, showing that the new technique dominate on all tested instances.Comment: Full (tech-report) version of ECAI 2008 short pape

Ontogeny of electric organ and electric organ discharge in Campylomormyrus rhynchophorus (Teleostei: Mormyridae)

The aim of this study was a longitudinal description of the ontogeny of the adult electric organ of Campylomormyrus rhynchophorus which produces as adult an electric organ discharge of very long duration (ca. 25 ms). We could indeed show (for the first time in a mormyrid fish) that the electric organ discharge which is first produced early during ontogeny in 33-mm-long juveniles is much shorter in duration and has a different shape than the electric organ discharge in 15-cm-long adults. The change from this juvenile electric organ discharges into the adult electric organ discharge takes at least a year. The increase in electric organ discharge duration could be causally linked to the development of surface evaginations, papillae, at the rostral face of the electrocyte which are recognizable for the first time in 65-mm-long juveniles and are most prominent at the periphery of the electrocyte.Leibniz-Gemeinschaft http://dx.doi.org/10.13039/501100001664Peer Reviewe

Permafrost-carbon mobilization in Beringia caused by deglacial meltwater runoff, sea-level rise and warming

During the last deglaciation (18–8 kyr BP), shelf flooding and warming presumably led to a large-scale decomposition of permafrost soils in the mid-to-high latitudes of the Northern Hemisphere. Microbial degradation of old organic matter released from the decomposing permafrost potentially contributed to the deglacial rise in atmospheric CO2 and also to the declining atmospheric radiocarbon contents (Δ14C). The significance of permafrost for the atmospheric carbon pool is not well understood as the timing of the carbon activation is poorly constrained by proxy data. Here, we trace the mobilization of organic matter from permafrost in the Pacific sector of Beringia over the last 22 kyr using mass-accumulation rates and radiocarbon signatures of terrigenous biomarkers in four sediment cores from the Bering Sea and the Northwest Pacific. We find that pronounced reworking and thus the vulnerability of old organic carbon to remineralization commenced during the early deglaciation (~16.8 kyr BP) when meltwater runoff in the Yukon River intensified riverbank erosion of permafrost soils and fluvial discharge. Regional deglaciation in Alaska additionally mobilized significant fractions of fossil, petrogenic organic matter at this time. Permafrost decomposition across Beringia's Pacific sector occurred in two major pulses that match the Bølling-Allerød and Preboreal warm spells and rapidly initiated within centuries. The carbon mobilization likely resulted from massive shelf flooding during meltwater pulses 1A (~14.6 kyr BP) and 1B (~11.5 kyr BP) followed by permafrost thaw in the hinterland. Our findings emphasize that coastal erosion was a major control to rapidly mobilize permafrost carbon along Beringia's Pacific coast at ~14.6 and ~11.5 kyr BP implying that shelf flooding in Beringia may partly explain the centennial-scale rises in atmospheric CO2 at these times. Around 16.5 kyr BP, the mobilization of old terrigenous organic matter caused by meltwater-floods may have additionally contributed to increasing CO2 levels

Cross-Language Question Re-Ranking

We study how to find relevant questions in community forums when the language of the new questions is different from that of the existing questions in the forum. In particular, we explore the Arabic-English language pair. We compare a kernel-based system with a feed-forward neural network in a scenario where a large parallel corpus is available for training a machine translation system, bilingual dictionaries, and cross-language word embeddings. We observe that both approaches degrade the performance of the system when working on the translated text, especially the kernel-based system, which depends heavily on a syntactic kernel. We address this issue using a cross-language tree kernel, which compares the original Arabic tree to the English trees of the related questions. We show that this kernel almost closes the performance gap with respect to the monolingual system. On the neural network side, we use the parallel corpus to train cross-language embeddings, which we then use to represent the Arabic input and the English related questions in the same space. The results also improve to close to those of the monolingual neural network. Overall, the kernel system shows a better performance compared to the neural network in all cases.Comment: SIGIR-2017; Community Question Answering; Cross-language Approaches; Question Retrieval; Kernel-based Methods; Neural Networks; Distributed Representation

Exosomal release of L-plastin by breast cancer cells facilitates metastatic bone osteolysis

Bone metastasis from breast and prostate carcinomas is facilitated by activation of bone-resorbing osteoclasts. Using proteomics approaches, we have identified peroxiredoxin-4 (PRDX4) as a cancer-secreted mediator of osteoclastogenesis. We now report characterization of L-plastin in the conditioned media (CM) of MDA-MB-231 human breast cancer cells using immunoblotting and mass spectrometry. The osteoclastogenic potential of MDAMB-231 CM with siRNA-silenced L-plastin was significantly reduced. L-plastin was detected in cancer-derived exosomes, and inhibition of exosomal release significantly decreased the osteoclastogenic capacity of MDA-MB-231 CM. When added to osteoclast precursors primed with RANKL for 2 days, recombinant L-plastin induced calcium/NFATc1-mediated osteoclastogenesis to the levels similar to continuous treatment with RANKL. Using shRNA, we generated MDA-MB-231 cells lacking L-plastin, PRDX4, or both and injected these cell populations intratibially in CD-1 immunodeficient mice. Micro-CT and histomorphometric analysis demonstrated a complete loss of osteolysis when MDA-MB-231 cells lacking both L-plastin and PRDX4 were injected. A meta-analysis established an increase in L-plastin and PRDX4 mRNA expression in numerous human cancers, including breast and prostate carcinomas. This study demonstrates that secreted L-plastin and PRDX4 mediate osteoclast activation by human breast cancer cells

Conceitos de química dos ingressantes nos cursos de graduação do Instituto de Química da Universidade de São Paulo

A diagnostic instrument was developed to evaluate the basic chemistry concepts held by freshmen students of the three Chemistry undergraduate courses offered by the University of São Paulo. The instrument minimizes the use of algorithms or memorization by students and values high-order cognitive skills. Analysis of the students' performances reveals systematic use of "displacement reaction" as an algorithm and a mechanical use of Le Chatelier's Principle. Failure in comprehending the chemical equation and chemical language drives students to alternative models for chemical reactions in aqueous solution. For instance, reaction would occur between "ionic pairs" and/or between species situated in separate compartments

O marketing comportamental no processo de fidelização do consumidor online - Estudo de caso: FNAC.PT

Mestrado em Controlo de Gestão e dos NegóciosCom a crescente complexidade que os mercados apresentam atualmente, tornou-se obrigatório para as empresas redesenharem novas estratégias – diferenciadoras e inovadoras – que acompanhem estas constantes mutações. Nesta nova era, intitulada era da informação, a internet possibilita uma economia à escala global, onde a circulação e a troca de dados é feita de forma livre, rápida e sem barreiras geográficas. Todos esses fatores impulsionaram que o consumidor assumisse um novo papel nas relações comerciais: mais ativo, mais exigente, bastante mais informado e, por consequência, mais desconfiado e caprichoso. De facto, surgiram novos desafios que estimularam a renovação de alguns parâmetros do marketing tradicional. O conceito de brand equity ganhou relevância, assim como se tornou fulcral para a empresa ter o cliente como centro dos seus esforços, numa perspetiva de marketing one-to-one, de forma a responder aos seus desejos. Nesta fase, em que a internet e o consumidor estão intimamente ligados, cabe às empresas retirar o maior proveito desta relação: por um lado, satisfazer os caprichos e as expetativas dos consumidores, com a informação absorvida dos dados que o marketing comportamental disponibiliza, e por outro, aproveitar um novo canal de comunicação para chegar mais rápida e eficazmente ao consumidor. Contudo, para que as empresas consigam efetivamente alcançar novos consumidores e principalmente que os consigam fidelizar num contexto de e-commerce é crucial a implementação de estratégias ao nível do marketing digital que permitam às empresas explorar e beneficiar dos paradigmas do novo contexto atual.With the increasing complexity of the markets at present, it became mandatory for companies to redesign their strategies – in a differentiating and innovative way - that will follow these constant changes. In this new era, called by the information age, the internet allows a global economy, where the circulation and exchange of data is done freely, quickly and without barriers. All these factors have improved for the consumer to acquire a new role in business relationships: more active, more demanding, much more informed and, therefore, more suspicious. In fact, new challenges have emerged which stimulated the renewal of some parameters of traditional marketing. The concept of brand equity gained prominence, and became central to the companies to have the customer as the center of their efforts, in a marketing one-to-one perspective and hoping to meet their expectations. At this stage, when the Internet and the consumer are closely linked, it is for the companies take full advantage of this relationship: on the one hand, satisfy the whims and desires of consumers supported the data absorbed by behavioral marketing, and secondly, make a new channel communication (which can be much more efficient than traditional). However, for companies to be able to effectively reach new consumers and especially able to retain them in the context of e-commerce, it is crucial the implementation of digital strategies that allow companies to explore and benefit from new paradigms of the current context