Maximally-localized Wannier functions for entangled energy bands

We present a method for obtaining well-localized Wannier-like functions (WFs) for energy bands that are attached to or mixed with other bands. The present scheme removes the limitation of the usual maximally-localized WFs method (N. Marzari and D. Vanderbilt, Phys. Rev. B 56, 12847 (1997)) that the bands of interest should form an isolated group, separated by gaps from higher and lower bands everywhere in the Brillouin zone. An energy window encompassing N bands of interest is specified by the user, and the algorithm then proceeds to disentangle these from the remaining bands inside the window by filtering out an optimally connected N-dimensional subspace. This is achieved by minimizing a functional that measures the subspace dispersion across the Brillouin zone. The maximally-localized WFs for the optimal subspace are then obtained via the algorithm of Marzari and Vanderbilt. The method, which functions as a postprocessing step using the output of conventional electronic-structure codes, is applied to the s and d bands of copper, and to the valence and low-lying conduction bands of silicon. For the low-lying nearly-free-electron bands of copper we find WFs which are centered at the tetrahedral interstitial sites, suggesting an alternative tight-binding parametrization.Comment: 13 pages, with 9 postscript figures embedded. Uses REVTEX and epsf macro

Ovarian Abscess With Spontaneous Vaginal Drainage.

The occurrence of a rare ovarian abscess, spontaneously drained through the vagina after an abdominal hysterectomy is described. The treatment was an oophorectomy. The various forms of primary ovarian abscess are discussed in connection with these observations. This case illustrates the need for adequate manipulation of the gonad during pelvic surgery in order to avoid parenchymal contamination and the subsequent formation of such abscesses.11561596159

Comment on "Critique of q-entropy for thermal statistics" by M. Nauenberg

It was recently published by M. Nauenberg [1] a quite long list of objections about the physical validity for thermal statistics of the theory sometimes referred to in the literature as {\it nonextensive statistical mechanics}. This generalization of Boltzmann-Gibbs (BG) statistical mechanics is based on the following expression for the entropy: S_q= k\frac{1- \sum_{i=1}^Wp_i^q}{q-1} (q \in {\cal R}; S_1=S_{BG} \equiv -k\sum_{i=1}^W p_i \ln p_i) . The author of [1] already presented orally the essence of his arguments in 1993 during a scientific meeting in Buenos Aires. I am replying now simultaneously to the just cited paper, as well as to the 1993 objections (essentially, the violation of "fundamental thermodynamic concepts", as stated in the Abstract of [1]).Comment: 7 pages including 2 figures. This is a reply to M. Nauenberg, Phys. Rev. E 67, 036114 (2003

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging

We present a measurement of the top quark pair ($t\bar{t}$) production cross section ($\sigma_{t\bar{t}}$) in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using 230 pb$^{-1}$ of data collected by the D0 experiment at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), missing transverse energy, and jets in the final state. We employ lifetime-based b-jet identification techniques to further enhance the $t\bar{t}$ purity of the selected sample. For a top quark mass of 175 GeV, we measure $\sigma_{t\bar{t}}=8.6^{+1.6}_{-1.5}(stat.+syst.)\pm 0.6(lumi.)$ pb, in agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let

Stability of the monoclinic phase in the ferroelectric perovskite PbZr(1-x)TixO3

Recent structural studies of ferroelectric PbZr(1-x)TixO3 (PZT) with x= 0.48, have revealed a new monoclinic phase in the vicinity of the morphotropic phase boundary (MPB), previously regarded as the the boundary separating the rhombohedral and tetragonal regions of the PZT phase diagram. In the present paper, the stability region of all three phases has been established from high resolution synchrotron x-ray powder diffraction measurements on a series of highly homogeneous samples with 0.42 <=x<= 0.52. At 20K the monoclinic phase is stable in the range 0.46 <=x<= 0.51, and this range narrows as the temperature is increased. A first-order phase transition from tetragonal to rhombohedral symmetry is observed only for x= 0.45. The MPB, therefore, corresponds not to the tetragonal-rhombohedral phase boundary, but instead to the boundary between the tetragonal and monoclinic phases for 0.46 <=x<= 0.51. This result provides important insight into the close relationship between the monoclinic phase and the striking piezoelectric properties of PZT; in particular, investigations of poled samples have shown that the monoclinic distortion is the origin of the unusually high piezoelectric response of PZT.Comment: REVTeX file, 7 figures embedde

BB flavour tagging using charm decays at the LHCb experiment

An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes $B^+ \to J/\psi \, K^+$ and $B^0 \to J/\psi \, K^{*0}$ using $3.0\mathrm{\,fb}^{-1}$ of data collected by the LHCb experiment at $pp$ centre-of-mass energies of $7\mathrm{\,TeV}$ and $8\mathrm{\,TeV}$. Its tagging power on these samples of $B \to J/\psi \, X$ decays is $(0.30 \pm 0.01 \pm 0.01) \%$.Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm

Evidence for the strangeness-changing weak decay Ξb−→Λb0π−\Xi_b^-\to\Lambda_b^0\pi^-

Using a $pp$ collision data sample corresponding to an integrated luminosity of 3.0~fb$^{-1}$, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay $\Xi_b^-\to\Lambda_b^0\pi^-$. No $b$ hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be ${{f_{\Xi_b^-}}\over{f_{\Lambda_b^0}}}{\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) = (5.7\pm1.8^{+0.8}_{-0.9})\times10^{-4}$, where $f_{\Xi_b^-}$ and $f_{\Lambda_b^0}$ are the $b\to\Xi_b^-$ and $b\to\Lambda_b^0$ fragmentation fractions, and ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ is the branching fraction. Assuming $f_{\Xi_b^-}/f_{\Lambda_b^0}$ is bounded between 0.1 and 0.3, the branching fraction ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ would lie in the range from $(0.57\pm0.21)\%$ to $(0.19\pm0.07)\%$.Comment: 7 pages, 2 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm

Fine-needle Aspiration Biopsy For Breast Lesions: A Comparison Between Two Devices For Obtaining Cytological Samples

Context and Objective: Fine-needle aspiration biopsy has been accepted worldwide for breast lesions. However, some questions remain, including the appropriateness of the puncture method. The objective of this work was to compare aspirates obtained by the auto-vacuum device and by the syringe pistol holder. Design and Setting: Randomized trial for validation of diagnostic method, at Hospital das Clinicas do Universidade Federal de Goiás and Hospital Araújo Jorge, Goiânio. Methods: 351 patients presenting breast lumps underwent fine-needle aspiration biopsy, either with the auto-vacuum device or the syringe pistol holder. A single cytopathologist analyzed all of the cytology slides. The rates of insufficient material, cellularity, cell distortion and background hemorrhage were evaluated. Results: The percentages of insufficient material were 16% and 22% (p = 0.18), for the auto-vacuum and pistol aspirates, respectively. Good cellularity was seen in 34% of autovacuum and 29% of pistol samples (p = 0.4). Cell distortion was seen in 31 and 26 cases, respectively (p = 07). Background hemorrhage occurred in 63 (35%) and 54 cases (31%) (p = 0.2), for auto-vacuum and pistol. The sensitivity was 88% and 86%; specificity 99% and 100%, positive predictive value 96% and and 100%, negative predictive value 96% and 95% and total occuracy 76% and 75% for the auto-vacuum and pistol, respectively. Conclusion: The results obtained from the two fine-needle aspiration biopsy methods were equivalent. Therefore, the auto-vacuum device is a good option for obtaining aspirates for cytology.1236271276Catania, S., Ciatto, S., Breast cytology: Instruments and technique (1992) Breast Cytology in Clinical Practice, pp. 11-60. , In: Ciatto S, editor. London: Martin DunitzDe Freitas Jr., R., Hamed, H., Fentiman, I., Fine needle aspiration cytology of palpable breast lesions (1992) Br J Clin Pract, 46 (3), pp. 187-190Franzen, S., Zajicek, J., Aspiration biopsy in diagnosis of palpable lesions of the breast. Critical review of 3479 consecutive biopsies Acta (1968) Radiol Ther Phys Biol, 7 (4), pp. 241-262Souza, J.A., Freitas Jr., R., Moreita, M.A.R., Philocreon, G.R., Acurácia da sensação tátil da PAAF no diagnóstico de less̄ocs mamárias (1995) Rev Bras Mastologia, 5 (3), pp. 7-10Freitas Júnior, R., Hamed, H., Millis, R.R., Tomas, N.M.A., Fentiman, I.S., Fine needle aspiration of breast lesions using auto-vacuum dispositive (1996) Rev Bras Mastologia, 6 (3), pp. 126-128de Freitas Júnior, R., Giraldo, P.C., Rerrori, O., Vieira-Matos, A.N., Tambascia, J.K., Fine needle aspiration biopsy of solid tumours by auto-vacuum system: A study in rats (1992) Eur J Surg Oncol, 18 (6), pp. 605-607Boccato, P., How to treat the aspirated material (1992) Breast Cytology in Clinical Practice, pp. 61-64. , In: Ciatto, S, editor London: Martin Dunitz(1987) International Union Against Cancer, , UICC. TNM classification of malignant tumors. Berlin: Springer-Verlag(1982) Am J Clin Pathol, 78 (6), pp. 806-816. , The World Health Organization Histological Typing of Breast Tumors - Second Edition. The World OrganizationGelabert, H.A., Hsiu, J.G., Mullen, J.T., Jaffe, A.H., D'Amato, N.A., Prospective evaluation of the rate of fine-needle aspiration biopsy in the diagnosis and management of patiencs with palpable solid breast lesions (1990) Am Surg, 56 (4), pp. 263-267Rouquayrol, M.Z., Epidemiologia e saúde (1988), Rio de Janeiro: Medsi - Editora CientíficaRoberts, J.C., Rainsbury, R.M., 'Tactile sensation: A new clinical sign during fine needle aspiration of breast lumps Ann (1994) R Coll Surg Eng, 76 (2), pp. 136-138Henderson, M.A., McCready, D.R., A simple technique for fine needle aspiration cytology (1994) J Am Coll Surg, 179 (4), pp. 471-473Sasaki, J., Izu, K., Automatic fine needle aspiration pistol specially designed for small tumors (1998) Acta Cytol, 42 (3), pp. 829-830Tao, L.C., Smith, J.W., Fine-needle aspiration biopsy using a newly-developed pencil-grip syringe holder (1999) Diagn Cytopathol, 20 (2), pp. 99-104Parel, J.J., Garrell, P.C., Smallwood, J.A., Fine needle aspiration cytology of breast masses: An evaluation of its accuracy and reasons for diagnostic failure (1987) Ann R Coll Surg Engl, 69 (4), pp. 156-159Abele, J., Stanley, M.W., Rollnis, S.D., Miller, T.R., What constitutes an adequate smear in fine-needle aspiration cytology of the breast? (1998) Cancer, 84 (1), pp. 57-61Zajdela, A., Ghossein, N.A., Pilleron, J.P., Ennuyer, A., The value of aspiration cytology in the diagnosis of breast cancer: Experience at the Fondation Curie (1975) Cancer, 35 (2), pp. 499-506Layfield, L.J., Dodd, L.G., Cytologically low grade malignancies: An important interpretative pitfall responsible for false negative diagnoses in fine-needle aspiration of the breast (1996) Diagn Cytopathol, 15 (3), pp. 250-259Feichter, G.E., Haberthür, F., Gobat, S., Dalquen, P., Breast cytology. Statistical analysis and cytohistologic correlations (1997) Acta Cytol, 41 (2), pp. 327-332Arisio, R., Cuccorese, C., Accinelli, G., Mano, M.P., Bordon, R., Fessia, L., Role of fine-needle aspiration biopsy in breast lesions: Analysis of a series of 4,110 cases (1998) Diagn Cytopathol, 18 (6), pp. 462-467Ariga, R., Bloom, K., Reddy, V.B., Fine-needle aspiration of clinically suspicious palpable breast masses with histopathologic correlation (2002) Am J Surg, 184 (5), pp. 410-41

Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex

Absolute luminosity measurements with the LHCb detector at the LHC

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic "van der Meer scan" method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overall precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.Comment: 48 pages, 19 figures. Results unchanged, improved clarity of Table 6, 9 and 10 and corresponding explanation in the tex