Transport through a quantum ring, a dot and a barrier embedded in a nanowire in magnetic field

We investigate the transport through a quantum ring, a dot and a barrier embedded in a nanowire in a homogeneous perpendicular magnetic field. To be able to treat scattering potentials of finite extent in magnetic field we use a mixed momentum-coordinate representation to obtain an integral equation for the multiband scattering matrix. For a large embedded quantum ring we are able to obtain Aharanov-Bohm type of oscillations with superimposed narrow resonances caused by interaction with quasi-bound states in the ring. We also employ scattering matrix approach to calculate the conductance through a semi-extended barrier or well in the wire. The numerical implementations we resort to in order to describe the cases of weak and intermediate magnetic field allow us to produce high resolution maps of the ``near field'' scattering wave functions, which are used to shed light on the underlying scattering processes.Comment: RevTeX, 13 pages with included postscript figures, high resolution version available at http://hartree.raunvis.hi.is/~vidar/Rann/VG_04.pd

Parametric Inversion of Brillouin spectra using L-curve criterion to enhance the accuracy of distributed strain measurement

International audienceTo ensure stability and durability of engineering structure in natural soil, optical fiber sensors have gained interest over last decade. In addition to conventional geophysical sensors, Brillouin spectra based sensor enables to perform distributed strain measurement. Its algorithm performs a strain measurement with a 40cm spatial sampling over several kilometers. The monitoring of engineering installations needs a centimeter spatial sampling and a better strain accuracy. Previous works highlighted that the industrialized algorithm has great limitation for the exploitation of the local information contained into Brillouin spectra. Indeed, based on its asymmetry and broadening, it is possible to estimate local Brillouin frequencies with a better strain accuracy. We propose here to apply a parametric inverse method using L-curve criterion to estimate the strain with a 5cm spatial sampling. To validate this method, a one-to-one scale experiment has been implemented by optical fiber cable at several depths. Comparing the distributed strain provided by the Brillouin based sensor and our algorithm with a reference strain sensor, the proposed algorithm successfully fulfills the combination of a 5cm spatial sampling over kilometers and a high strain accuracy

Structures of the (Imidazole)nH+ ... Ar (n=1,2,3) complexes determined from IR spectroscopy and quantum chemical calculations

Here, we present new cryogenic infrared spectra of the (Imidazole)$_{n}H^+$ (n=1,2,3) ions. The data was obtained using helium tagging infrared predissociation spectroscopy. The new results were compared with the data obtained by Gerardi et al. (Chem. Phys. Lett. 501:172–178, 2011) using the same technique but with argon as a tag. Comparison of the two experiments, assisted by theoretical calculations, allowed us to evaluate the preferable attachment positions of argon to the (Imidazole)$_{n}H^+$ frame. Argon attaches to nitrogen-bonded hydrogen in the case of the (Imidazole)$H^+$ ion, while in (Imidazole)$_{2}H^+$ and (Imidazole)$_{3}H^+$ the preferred docking sites for the argon are in the center of the complex. This conclusion is supported by analyzing the spectral features attributed to the N–H stretching vibrations. Symmetry adapted perturbation theory (SAPT) analysis of the non-covalent forces between argon and the (Imidazole)$_{n}H^+$ (n=1,2,3) frame revealed that this switch of docking preference with increasing complex size is caused by an interplay between induction and dispersion interactions

Multimessenger search for sources of gravitational waves and high-energy neutrinos: Initial results for LIGO-Virgo and IceCub

We report the results of a multimessenger search for coincident signals from the LIGO and Virgo gravitational-wave observatories and the partially completed IceCube high-energy neutrino detector, including periods of joint operation between 2007–2010. These include parts of the 2005–2007 run and the 2009–2010 run for LIGO-Virgo, and IceCube’s observation periods with 22, 59 and 79 strings. We find no significant coincident events, and use the search results to derive upper limits on the rate of joint sources for a range of source emission parameters. For the optimistic assumption of gravitational-wave emission energy of 10−2  M⊙c2 at ∼150  Hz with ∼60  ms duration, and high-energy neutrino emission of 1051  erg comparable to the isotropic gamma-ray energy of gamma-ray bursts, we limit the source rate below 1.6×10−2  Mpc−3 yr−1. We also examine how combining information from gravitational waves and neutrinos will aid discovery in the advanced gravitational-wave detector era

Junimea Vinului Iași – un grup local de inițiativă și promovare oenologică

This paper presents the Junimea Vinului Iași group description. This group is made up of wine lovers with different backrounds and hase as a aim to promote the culture of wine quality. The group holds regular meetings were they discussed various oenological topics, also wine tastings and promoting various wine producers in cyberspace and beyond. As a result of a year of activity, the group has developed co-opting various subject areas and develop a series of recommendations that are promoted via internet (social media networking)

Rezultatele preliminare ale tratamentului cu tocilizumab al pacienţilor cu artrită reumatoidă

Conferinţa naţională în medicina internă din Republica Moldova cu participare internaţională, 19-20 mai 2011, Chişinău, Republica MoldovaSummary. IL-6 plays an important role in the inflammatory cascade in rheumatoid arthritis (RA). Tocilizumab is one of the most innovative biological products, which aims at inhibiting the action of IL-6 proliferation, thereby reducing the inflammatory response and enhances the development of RA. The results presented in this paper are preliminary because the surveillance period was not completed in all patients included.Actualitate: IL-6 joacă un rol important în procesul inflamatoriu în artrita reumatoidă (AR). Tocilizumabul este unul dintre cele mai noi preparate biologice, acţiunea căruia ţinteşte inhibiţia proliferării IL-6, astfel diminuând răspunsul inflamator şi ameliorând evoluţia AR. Rezultatele prezentate în această lucrare sunt preliminare, pentru că perioada de supraveghere nu a fost încheiată la toţi pacienţii incluşi în studiu.Scopul lucrării. Acest studiu a avut scopul de a evalua eficacitatea şi inofensivitatea preparatului tocilizumab în combinaţie cu metotrexat (MTX) şi a aprecia influenţa tratamentului biologic asupra parametrilor clinici şi paraclinici ai AR. Totodată, am evaluat comparativ rezultatele din grupul de tratament cu monoterapie cu MTX al pacienţilor cu AR. Material şi metode. Studiul a inclus 68 de pacienţi cu AR (6 bărbaţi şi 62 de femei) conform criteriilor ACR, cu durata lungă a maladiei (durata medie a bolii până la 9,45 ani). Toţi pacienţii aveau sub 60 ani, nu aveau comorbidităţi severe, istoric de tuberculoză sau hepatită virală. Bolnavii au fost randomizaţi în 2 grupuri, comparabile ca vârstă şi durată a maladiei. Primul grup (A) a fost constituit din 38 de persoane, care au administrat 6 perfuzii lunare cu tocilizumab (8 mg/kg) în combinaţie cu MTX (10 mg/săptămână) şi metilprednisolon 4 mg zilnic. Cel de al doilea grup (B) a inclus 30 de pacienţi pe tratament cu MTX (10- 15 mg/săptămână) şi metilprednisolon 4 mg zilnic. Pacienţii au fost examinaţi înainte de randomizare, conform unui plan comprehensiv. Rezultate. Toţi bolnavii din grupul A au remarcat o diminuare a redorii matinale de la 145 ± 12,41 până la 30 ± 9,14 min. (p <0,005), în comparaţie cu o ameliorare mai modestă a acestui simptom în grupul B (de la 156 ± 15,06 min. până la 100 ± 10,31 min.). Pacienţii din grupul A au înregistrat o scădere a numărului de articulaţii tumefiate, de la 9,58 ± 1,91 până la 2,28 ± 1,96 (p <0,05), în timp ce în grupul B această evoluţie a fost mai puţin importantă (de la 7,13 ± 0,47 până la 6,24 ± 1,21). Am înregistrat, de asemenea, o dinamică pozitivă a indicilor de laborator, în particular a VSH, cu o valoare medie care a scăzut de la 45 ± 4,45 până la 20 ± 4,23 (p <0,005) în grupul A, în comparaţie cu grupul B (de la 36 ± 2,96 până la 30 ± 3,45, fără valoare statistică). Proteina C-reactivă, la fel, a înregistrat o dinamică pozitivă în grupul A – de la 7,50 ± 2,67 până la 2,75 ± 1,96 (p <0,05). Scorul DAS-28 s-a ameliorat la 73,68% din pacienţii cu tocilizumab versus 36,67% în grupul B. Scorul HAQ, apreciat înainte şi în timpul tratamentului, s-a ameliorat impresionant la 81,58% din pacienţi începând cu a doua perfuzie, comparativ cu 53,33% din bolnavii grupului B în cele 6 luni de tratament. Concluzii. Pacienţii cu AR trataţi cu tocilizumab au demonstrat o reducere impresionantă a redorii matinale, a indicelui DAS-28, inclusiv a numărului de articulaţii dureroase, în special tumefiate; a VSH şi proteinei C-reactive. Ca rezultat al eficacităţii clinice a preparatului biologic tocilizumab, la pacienţii din acest grup a fost înregistrată o ameliorare mai importantă a calităţii vieţii, evaluate în baza chestionarului HAQ

Shedding light on the performance of a pyrosequencing assay for drug-resistant tuberculosis diagnosis

BACKGROUND: Rapid molecular diagnostics, with their ability to quickly identify genetic mutations associated with drug resistance in Mycobacterium tuberculosis clinical specimens, have great potential as tools to control multi- and extensively drug-resistant tuberculosis (M/XDR-TB). The Qiagen PyroMark Q96 ID system is a commercially available pyrosequencing (PSQ) platform that has been validated for rapid M/XDR-TB diagnosis. However, the details of the assay’s diagnostic and technical performance have yet to be thoroughly investigated in diverse clinical environments. METHODS: This study evaluates the diagnostic performance of the PSQ assay for 1128 clinical specimens from patients from three areas of high TB burden. We report on the diagnostic performance of the PSQ assay between the three sites and identify variables associated with poor PSQ technical performance. RESULTS: In India, the sensitivity of the PSQ assay ranged from 89 to 98 % for the detection of phenotypic resistance to isoniazid, rifampicin, fluoroquinolones, and the injectables. In Moldova, assay sensitivity ranged from 7 to 94 %, and in South Africa, assay sensitivity ranged from 71 to 92 %. Specificity was high (94–100 %) across all sites. The addition of eis promoter sequencing information greatly improved the sensitivity of kanamycin resistance detection in Moldova (7 % to 79 %). Nearly all (89.4 %) sequencing reactions conducted on smear-positive, culture-positive specimens and most (70.8 %) reactions conducted on smear-negative, culture-positive specimens yielded valid PSQ reads. An investigation into the variables influencing sequencing failures indicated smear negativity, culture negativity, site (Moldova), and sequencing of the rpoB, gyrA, and rrs genes were highly associated with poor PSQ technical performance (adj. OR > 2.0). CONCLUSIONS: This study has important implications for the global implementation of PSQ as a molecular TB diagnostic, as it demonstrates how regional factors may impact PSQ diagnostic performance, while underscoring potential gene targets for optimization to improve overall PSQ assay technical performance. TRIAL REGISTRATION: ClinicalTrials.gov (#NCT02170441). Registered 12 June 2014. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-016-1781-y) contains supplementary material, which is available to authorized users