Localization of fermions in different domain wall models

Localization of fermions is studied in different gravitational domain wall models. These are generalizations of the brane-world models considered by Randall and Sundrum, but which also allow gravitational localization. Therefore, they might be considered as possible realistic scenarios for phenomenology.Comment: RevTeX, 6 pages, 10 figure

The Tisa initiative: An overview of market access issues

This paper aims to provide insights into the market access issues arising in such negotiations. Should TISA negotiations result in participants exchanging the best commitments they have so far undertaken in their preferential trade agreements (PTAs) - a reasonable starting point - 'TISA market access commitments would go well beyond GATS commitments and services offers tabled in the Doha Round. While this would be in itself a significant outcome (especially in terms of predictability and stability), we also highlight, however, that the real economic benefits would be reduced by the fact that a number of participants have already exchanged significant concessions amongst themselves through bilateral PTAs. Further, and more importantly, exchanging 'best PTA' commitments would not meet the participants' most important export interests. These have often remained unaddressed in many of the previous bilateral negotiations or involve countries not currently participating in TISA. Addressing better these export interests would require going beyond an exchange of 'best PTA' commitments among TISA participants - with the more difficult policy and negotiating decisions that this implies - and/or seeking to expand the group of participants. We also discuss the different forms that such a plurilateral agreement may take vis-à-vis the WTO framework

Strengthening measurements from the edges: application-level packet loss rate estimation

Network users know much less than ISPs, Internet exchanges and content providers about what happens inside the network. Consequently users cannot either easily detect network neutrality violations or readily exercise their market power by knowledgeably switching ISPs. This paper contributes to the ongoing efforts to empower users by proposing two models to estimate -- via application-level measurements -- a key network indicator, i.e., the packet loss rate (PLR) experienced by FTP-like TCP downloads. Controlled, testbed, and large-scale experiments show that the Inverse Mathis model is simpler and more consistent across the whole PLR range, but less accurate than the more advanced Likely Rexmit model for landline connections and moderate PL

Effect of energy density and virginiamycin supplementation in diets on growth performance and digestive function of finishing steers.

ObjectiveThis study was determined the influence of virginiamycin supplementation on growth-performance and characteristics of digestion of cattle with decreasing dietary net energy value of the diet for maintenance (NEm) from 2.22 to 2.10 Mcal/kg.MethodsEighty crossbred beef steers (298.2±6.3 kg) were used in a 152-d performance evaluation consisting of a 28-d adaptation period followed by a 124-d growing-finishing period. During the 124-d period steers were fed either a lesser energy dense (LED, 2.10 Mcal/kg NEm) or higher energy dense (HED, 2.22 Mcal/kg NEm) diet. Diets were fed with or without 28 mg/kg (dry matter [DM] basis) virginiamycin in a 2×2 factorial arrangement. Four Holstein steers (170.4±5.6 kg) with cannulas in the rumen (3.8 cm internal diameter) and proximal duodenum were used in 4×4 Latin square experiment to study treatment effects on characteristics of digestion.ResultsNeither diet energy density nor virginiamycin affected average daily gain (p>0.10). As expected, dry matter intake and gain efficiency were greater (p<0.01) for LED- than for HED-fed steers. Virginiamycin did not affect estimated net energy value of the LED diet. Virginiamycin increased estimated NE of the HED diet. During daylight hours when the temperature humidity index averaged 81.3±2.7, virginiamycin decreased (p<0.05) ruminal temperature. Virginiamycin did not influence (p>0.10) ruminal or total tract digestion. Ruminal (p = 0.02) and total tract digestion (p<0.01) of organic matter, and digestible energy (p<0.01) were greater for HED vs LED. Ruminal microbial efficiency was lower (p<0.01) for HED vs LED diets.ConclusionThe positive effect of virginiamycin on growth performance of cattle is due to increased efficiency of energy utilization, as effects of virginiamycin on characteristics of digestion were not appreciable. Under conditions of high ambient temperature virginiamycin may reduce body temperature

Bayesian additive regression trees for probabilistic programming

Bayesian additive regression trees (BART) is a non-parametric method to approximate functions. It is a black-box method based on the sum of many trees where priors are used to regularize inference, mainly by restricting trees' learning capacity so that no individual tree is able to explain the data, but rather the sum of trees. We discuss BART in the context of probabilistic programming languages (PPL), i.e., we present BART as a primitive that can be used as a component of a probabilistic model rather than as a standalone model. Specifically, we introduce the Python library PyMC-BART, which works by extending PyMC, a library for probabilistic programming. We showcase a few examples of models that can be built using PyMC-BART, discuss recommendations for the selection of hyperparameters, and finally, we close with limitations of our implementation and future directions for improvement.Comment: 22 pages, 17 figure

Supporting strategy using system dynamics

This paper presents a protocol for supporting strategy development via system dynamics (SD) modeling in consultation with Chief Executive Officers (CEOs) of small organizations; it also reports on the effectiveness of this protocol one year after an initial study was conducted. The protocol was applied in five small organizations; it involves the development of a SD model that is used to generate scenarios of alternative strategic situations an organization may face. We found that when the CEOs identified more feedback loops and causal relationships among key resources through their modeling analyses, they increased their capacities to generate new strategic ideas through more developed mental models. However, those CEOs who were not able to generate alternative strategic ideas to overcome the challenges of scenarios presented during the simulation sessions found it difficult to make strategic decisions when the scenarios occurred one year after our intervention. This finding suggests that SD modeling can affect firm performance when the facilitation process helps CEOs reflect on potential strategic actions that can be taken in the future. When CEOs cannot change their strategic plans by imagining what should be done in a challenging scenario, they are not able to address challenging situations when they arise

Quantum simulation of Anderson and Kondo lattices with superconducting qubits

We introduce a mapping between a variety of superconducting circuits and a family of Hamiltonians describing localized magnetic impurities interacting with conduction bands. This includes the Anderson model, the single impurity one- and two-channel Kondo problem, as well as the 1D Kondo lattice. We compare the requirements for performing quantum simulations using the proposed circuits to those of universal quantum computation with superconducting qubits, singling out the specific challenges that will have to be addressed.Comment: Longer versio

In vitro activity of bedaquiline against rapidly growing nontuberculous mycobacteria

Bedaquiline (BDQ) has been proven to be effective in the treatment of multidrug-resistant tuberculosis. We hypothesized that BDQ could be a potential agent to treat nontuberculous mycobacterial (NTM) infection. The objective of this study was to evaluate the in vitro activity of BDQ against rapidly growing mycobacteria by assessing the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) against 18 NTM strains. For MIC determination we performed the resazurin microtitre assay broth dilution, and for the MBC the c.f.u. was determined. BDQ exhibited a strong inhibitory effect against most NTM tested; however, for some NTM strains the MBC was significantly higher than the MIC. A new finding is that Mycobacterium flavescens has a mutation in the gene atpE associated with natural resistance to BDQ. These preliminary promising results demonstrate that BDQ could be potentially useful for the treatment of NTM

Laser Induced Heating of Group IV Nanowires

Semiconductor nanowires (NWs) are fundamental structures for nanoscale devices. The excitation of NWs with laser beams results in thermal effects that can substantially change the spectral shape of the spectroscopic data. In particular, the interpretation of the Raman spectrum is greatly influenced by excitation induced temperature. A study of the interaction of the NWs with the excitation laser beam is essential to interpret the spectra. We present herein a finite element analysis of the interaction between the laser beam and the NWs. The resultas are applied to the interpretation of the Raman spectrum of bundles of NW