Charge Fractionalization on Quantum Hall Edges

We discuss the propagation and fractionalization of localized charges on the edges of quantum Hall bars of variable widths, where interactions between the edges give rise to Luttinger liquid behavior with a non-trivial interaction parameter g. We focus in particular on the separation of an initial charge pulse into a sharply defined front charge and a broader tail. The front pulse describes an adiabatically dressed electron which carries a non-integer charge, which is \sqrt{g} times the electron charge. We discuss how the presence of this fractional charge can, in principle, be detected through measurements of the noise in the current created by tunneling of electrons into the system. The results are illustrated by numerical simulations of a simplified model of the Hall bar.Comment: 15 page

Are there sharp fractional charges in Luttinger liquids?

We examine charge fractionalization by chiral separation in a one-dimensional fermion system described by Luttinger liquid theory. The focus is on the question of whether the fractional charges are quantum mechanically sharp, and in the analysis we make a distinction between the global charge, which is restricted by boundary conditions, and the local charge where a background contribution is subtracted. We show, by way of examples, that fractional charges of arbitrary values, all which are quantum mechanically sharp, can be introduced by different initial conditions. Since the system is gapless, excitations of arbitrary low frequency contribute to the fluctuations, it is important to make a precise definition of sharp charges, and this we we do by subtraction of the ground state contribution. We very briefly comment on the relevance of our analysis for proposed experiments.Comment: One reference update

Acoustic characteristics and learner profiles of low, mid and high-level second language fluency

In the context of 90 adult Japanese learners of English with diverse L2 experience and 10 native speakers, this study examined the linguistic characteristics and learner profiles of low, mid and high-level fluency performance. The participants’ spontaneous speech samples were first rated by 10 native listeners for global fluency on a 9-point scale (1 =dysfluent, 9 = very fluent), and then divided into four proficiency groups via cluster analyses: low (n = 29), mid (n = 30), high (n = 31) and native (n = 10). Next, the dataset was analyzed for the number of pauses in mid/final clauses, articulation rate and the frequency of repetitions/self-corrections. According to the results of a series of ANOVAs, the number of final-clause pauses differentiated low and mid-level fluency performance; the number of mid-clause pauses differentiated mid and high-level performance; and articulation rate differentiated high and nativelike performance. The analyses also found that the participants’ L2 fluency was significantly associated with their length of residence profiles (0-18 years), but not with their age of arrival profiles (19-40 years)

Evaluating the capacity of human gut microorganisms to colonize the zebrafish larvae (Danio rerio)

Indexación: Scopus.In this study we evaluated if zebrafish larvae can be colonized by human gut microorganisms. We tested two strategies: (1) through transplantation of a human fecal microbiota and (2) by successively transplanting aerotolerant anaerobic microorganisms, similar to the colonization in the human intestine during early life. We used conventionally raised zebrafish larvae harboring their own aerobic microbiota to improve the colonization of anaerobic microorganisms. The results showed with the fecal transplant, that some members of the human gut microbiota were transferred to larvae. Bacillus, Roseburia, Prevotella, Oscillospira, one unclassified genus of the family Ruminococcaceae and Enterobacteriaceae were detected in 3 days post fertilization (dpf) larvae; however only Bacillus persisted to 7 dpf. Successive inoculation of Lactobacillus, Bifidobacterium and Clostridioides did not improve their colonization, compared to individual inoculation of each bacterial species. Interestingly, the sporulating bacteria Bacillus clausii and Clostridioides difficile were the most persistent microorganisms. Their endospores persisted at least 5 days after inoculating 3 dpf larvae. However, when 5 dpf larvae were inoculated, the proportion of vegetative cells in larvae increased, revealing proliferation of the inoculated bacteria and better colonization of the host. In conclusion, these results suggest that it is feasible to colonize zebrafish larvae with some human bacteria, such as C. difficile and Bacillus and open an interesting area to study interactions between these microorganisms and the host. © 2018 Valenzuela, Caruffo, Herrera, Medina, Coronado, Feijóo, Muñoz, Garrido, Troncoso, Figueroa, Toro, Reyes-Jara, Magne and Navarrete.https://www.frontiersin.org/articles/10.3389/fmicb.2018.01032/ful

GBS Platform Evaluation Using Field Instrumentation

A case history of the foundation behaviour of an offshore gravity base structure (GBS) is presented. The platform rests on an overconsolidated fissured clay, bounded, top and bottom, by pervious sand layers. Sixteen piezometers have been placed within this 30 m layer. Based on one-dimensional consolidation theory, independent analyses using both settlement and pore pressure measurements indicated a high degree of consolidation had occurred much sooner than was estimated in the initial design phase. These analyses indicated that laboratory oedometer tests underpredicted the coefficient of consolidation by one to two orders of magnitude. Updated settlements and stability analyses yielded 50% of the initially anticipated settlement and a 20% increase in the available safety factor. In addition, the certainty that the theory relating pore pressure to settlements was appropriate, led to confidence in the piezometer performance, and in turn the procedure used to install them

The Level 0 Trigger Decision Unit for the LHCb experiment

The Level 0 Decision Unit (L0DU) is one of the main components of the first trigger level (named level 0) of the LHCb experiment. This 16 layers custom board receives data from the calorimeter, muon and pile-up sub-triggers and computes the level 0 decision, reducing the rate from 40MHz to 1MHz. The processing is implemented in FPGA using a 40MHz synchronous pipelined architecture. The L0DU algorithm is fully configured via the Experiment Control System without any firmware reprogramming. An overall L0DU latency of less than 450ns has been achieved. The board was installed in the experimental area in April 2007 and since then has played a major role in the commissioning of the experiment

Robust sure independence screening for nonpolynomial dimensional generalized linear models

We consider the problem of variable screening in ultra-high-dimensional generalized linear models (GLMs) of nonpolynomial orders. Since the popular SIS approach is extremely unstable in the presence of contamination and noise, we discuss a new robust screening procedure based on the minimum density power divergence estimator (MDPDE) of the marginal regression coefficients. Our proposed screening procedure performs well under pure and contaminated data scenarios. We provide a theoretical motivation for the use of marginal MDPDEs for variable screening from both population as well as sample aspects; in particular, we prove that the marginal MDPDEs are uniformly consistent leading to the sure screening property of our proposed algorithm. Finally, we propose an appropriate MDPDE-based extension for robust conditional screening in GLMs along with the derivation of its sure screening property. Our proposed methods are illustrated through extensive numerical studies along with an interesting real data application

Robust Sure Independence Screening for Non-polynomial dimensional Generalized Linear Models

We consider the problem of variable screening in ultra-high dimensional (of non-polynomial order) generalized linear models (GLMs). Since the popular SIS approach is extremely unstable in the presence of contamination and noises, which may frequently arise in the large scale sample data (e.g., Omics data), we discuss a new robust screening procedure based on the minimum density power divergence estimator (MDPDE) of the marginal regression coefficients. Our proposed screening procedure performs extremely well both under pure and contaminated data scenarios. We also theoretically justify the use of this marginal MDPDEs for variable screening from the population as well as sample aspects; in particular, we prove that these marginal MDPDEs are uniformly consistent leading to the sure screening property of our proposed algorithm. We have also proposed an appropriate MDPDE based extension for robust conditional screening in the GLMs along with the derivation of its sure screening property.Comment: Work in Progres

Natural peptides with antioxidant activity from Atlantic cod and Atlantic salmon residual material

Summary. Water-soluble peptides/proteins with molecular weight below 10 kDa were isolated from residual material of cod (liver, skin, and cod mix i.e. skin, frames, and viscera), and salmon (skin, and salmon mix i.e. skin, frames, and viscera) by cut-off filtration. Peptide motifs with reported bioactivity were identified in all samples by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) (Orbitrap), bioinformatics, and database search. Peptides with potential type 2 diabetes, cardio system, immunomodulation, prolyl endopeptidase (PEP), and antioxidant activity were detected. The potential antioxidant activity in the samples was confirmed by two antioxidant assays, namely hydroxyl radical scavenging activity (HRSA), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical cation decolorization assay. In these assays the salmon samples were found to possess higher antioxidant activity than the cod samples. All samples except the cod skin were found to have higher antioxidant activity than alanine-histidine (AH), a dipeptide with known antioxidant activity. Industrial relevance. Residual material from fisheries and aquaculture makes up large quantities of material. Although previously regarded as waste this material has valuable components that are of interest for the biotech industry. The fractionation process utilized in this work offers the possibility for simple isolation of interesting peptides with antioxidant activity. This method should be of interest for the food industry and biotech industry for product development