Number-resolved master equation approach to quantum transport under the self-consistent Born approximation

We construct a particle-number(n)-resolved master equation (ME) approach under the self-consistent Born approximation (SCBA) for quantum transport through mesoscopic systems. The formulation is essentially non-Markovian and incorporates the interlay of the multi-tunneling processes and many-body correlations. The proposed n-SCBA-ME goes completely beyond the scope of the Born-Markov master equation, being applicable to transport under small bias voltage, in non-Markovian regime and with strong Coulomb correlations. For steady state, it can recover not only the exact result of noninteracting transport under arbitrary voltages, but also the challenging nonequilibrium Kondo effect. Moreover, the n-SCBA-ME approach is efficient for the study of shot noise.We demonstrate the application by a couple of representative examples, including particularly the nonequilibrium Kondo system.Comment: arXiv admin note: substantial text overlap with arXiv:1302.638

Full counting statistics of renormalized dynamics in open quantum transport system

The internal dynamics of a double quantum dot system is renormalized due to coupling respectively with transport electrodes and a dissipative heat bath. Their essential differences are identified unambiguously in the context of full counting statistics. The electrode coupling caused level detuning renormalization gives rise to a fast-to-slow transport mechanism, which is not resolved at all in the average current, but revealed uniquely by pronounced super-Poissonian shot noise and skewness. The heat bath coupling introduces an interdot coupling renormalization, which results in asymmetric Fano factor and an intriguing change of line shape in the skewness.Comment: 9 pages, 5 figure

A imigração chinesa em Portugal e a sua integração linguística e cultural na sociedade portuguesa

No mundo de hoje, mesmo que a maioria das pessoas convivam num território chamado “país”, existem numerosos conjuntos de pessoas a fazer movimentos migratórios transfronteiriços. Com a sua população enorme total, a China tornou-se no país com mais emigrantes no mundo. Especialmente época recente, com o desenvolvimento económico chinês e o desenvolvimento das políticas de favorecimento aos imigrantes na Europa, a população dos imigrantes chineses nos países europeus está a aumentar em grande escala. Entre eles está Portugal, que também acolheu bastantes imigrantes chineses, país onde são mais de 20 mil. Neste estudo analisam-se principalmente a situação actual, as causas, os modos e as teorias da migração internacional, os fluxos migratórios da China e a sua distribuição mundial, na Europa e, em particular, em Portugal. Este contexto permite entender a imigração chinesa em Portugal, a sua evolução histórica e as características da comunidade. Foram ainda feitos dois questionários para recolher dados concretos sobre a integração linguística e cultural dos imigrantes chineses na sociedade portuguesa. Portugal está a tornar-se cada vez mais multicultural. Com o crescimento notável da população dos imigrantes chineses, os estudos sobre esta comunidade tornam-se essenciais tanto no aspecto social, como no aspecto linguístico e cultural.In today’s world, even though most people live together in exclusive areas referred to as “countries”, many of them still participate in cross-border migration. With its massive total population, China has become the country with the most emigrants in the world. Especially recently, with rapid Chinese economic development and the creation of policies favoring migrants in Europe, the population of Chinese immigrants in European countries is increasing on a large scale. Among them is Portugal, which has received quite a few Chinese immigrants, totaling to over 20 thousands now. This study mainly analyzed the current situation, the causes, the methods and theories of international migration, migration flows from china and its global distribution in Europe, particularly in Portugal. This context allows us to understand Chinese immigration in Portugal as well as its historical development and community features. There were also two questionnaires which were made to collect concrete data on the linguistic and cultural integration of Chinese immigrants in Portuguese society. Portugal is becoming increasingly multicultural. With the remarkable growth of the population of Chinese immigrants, studies of this community have become essential not only for the social aspect, but also in regards to linguistics and local culture

From Copy to Practice: Follower’s Learning Behavior in Forex Social Trading

Forex social trading platforms endows novice investors with opportunities to trade on foreign exchange markets by mimicking the investment strategies of sophisticated traders. But concurrently, the copy-trading mechanism underlying these platforms foster a conducive learning environment whereby inexperience followers could evolve into independent traders by observing and learning from the trading behaviors of prominent traders. Drawing on observational learning theory, we advance learning efficiency and effectiveness as focal yardsticks to encapsulate followers’ learning performance and explore their effects on the profitability of followers’ first independent trades. Preliminary analysis conducted on a leading forex social trading platform reveals that traders’ trading consistency amplifies followers’ learning efficiency whereas traders’ profitability bolsters followers’ learning effectiveness. Furthermore, while our empirical findings attest to the criticality of learning effectiveness on followers’ ability to profit from their initial independent trades, speeding up the learning process may not guarantee better performance

Lactobacillus reuteri in digestive system diseases: focus on clinical trials and mechanisms

ObjectivesDigestive system diseases have evolved into a growing global burden without sufficient therapeutic measures. Lactobacillus reuteri (L. reuteri) is considered as a new potential economical therapy for its probiotic effects in the gastrointestinal system. We have provided an overview of the researches supporting various L. reuteri strains’ application in treating common digestive system diseases, including infantile colic, diarrhea, constipation, functional abdominal pain, Helicobacter pylori infection, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases.MethodsThe summarized literature in this review was derived from databases including PubMed, Web of Science, and Google Scholar.ResultsThe therapeutic effects of L. reuteri in digestive system diseases may depend on various direct and indirect mechanisms, including metabolite production as well as modulation of the intestinal microbiome, preservation of the gut barrier function, and regulation of the host immune system. These actions are largely strain-specific and depend on the activation or inhibition of various certain signal pathways. It is well evidenced that L. reuteri can be effective both as a prophylactic measure and as a preferred therapy for infantile colic, and it can also be recommended as an adjuvant strategy to diarrhea, constipation, Helicobacter pylori infection in therapeutic settings. While preclinical studies have shown the probiotic potential of L. reuteri in the management of functional abdominal pain, inflammatory bowel disease, diverticulitis, colorectal cancer and liver diseases, its application in these disease settings still needs further study.ConclusionThis review focuses on the probiotic effects of L. reuteri on gut homeostasis via certain signaling pathways, and emphasizes the importance of these probiotics as a prospective treatment against several digestive system diseases

Tet3 regulates synaptic transmission and homeostatic plasticity via DNA oxidation and repair.

Contrary to the long-held belief that DNA methylation of terminally differentiated cells is permanent and essentially immutable, post-mitotic neurons exhibit extensive DNA demethylation. The cellular function of active DNA demethylation in neurons, however, remains largely unknown. Tet family proteins oxidize 5-methylcytosine to initiate active DNA demethylation through the base-excision repair (BER) pathway. We found that synaptic activity bi-directionally regulates neuronal Tet3 expression. Functionally, knockdown of Tet or inhibition of BER in hippocampal neurons elevated excitatory glutamatergic synaptic transmission, whereas overexpressing Tet3 or Tet1 catalytic domain decreased it. Furthermore, dysregulation of Tet3 signaling prevented homeostatic synaptic plasticity. Mechanistically, Tet3 dictated neuronal surface GluR1 levels. RNA-seq analyses further revealed a pivotal role of Tet3 in regulating gene expression in response to global synaptic activity changes. Thus, Tet3 serves as a synaptic activity sensor to epigenetically regulate fundamental properties and meta-plasticity of neurons via active DNA demethylation