Randomized benchmarking of atomic qubits in an optical lattice

We perform randomized benchmarking on neutral atomic quantum bits (qubits) confined in an optical lattice. Single qubit gates are implemented using microwaves, resulting in a measured error per randomized computational gate of 1.4(1) x 10^-4 that is dominated by the system T2 relaxation time. The results demonstrate the robustness of the system, and its viability for more advanced quantum information protocols.Comment: 11 pages, 4 figure

Differential Light Shift Cancellation in a Magnetic-Field-Insensitive Transition of 87^{87}Rb

We demonstrate near-complete cancellation of the differential light shift of a two-photon magnetic-field-insensitive microwave hyperfine (clock) transition in $^{87}$Rb atoms trapped in an optical lattice. Up to $95(2)$ of the differential light shift is canceled while maintaining magnetic-field insensitivity. This technique should have applications in quantum information and frequency metrology.Comment: 5 pages, 4 figure

Infecções por Nocardia species: relato de 22 casos

Twenty-two cases of nocardial infections were diagnosed in our city between 1977- 1998. All patients whose clinical specimens showed Nocardia spp. at Gram stain, which were further confirmed by culture, were selected to be included in the study. Data from patients who were cured were compared with those from patients who died by statistical tests using EPIINFO version 6.04 software. Six isolates were identified as Nocardia asteroides complex, one as Nocardia asteroides sensu stricto and other as Nocardia brasiliensis. We had 17 cases of lung nocardiosis, being one out of them also a systemic disease. Other four cases of systemic nocardiosis were diagnosed: nocardial brain abscesses (one); nocardiosis of the jejunum (one); multiple cutaneous abscesses (one); and a case of infective nocardial endocarditis of prosthetic aortic valve. One patient had a mycetoma by N. brasiliensis. Fifteen (68.2%) out of 22 patients were immunosuppressed, being most (93.3%) by high-doses corticotherapy. Mortality by nocardial infection was 41%; mortality of systemic nocardiosis was 60%. Nocardiosis has a bad prognosis in immunosuppressed patients and also in non-immunosuppressed patients if the diagnosis is delayed. We propose that the delay in diagnosis should be examined in larger series to document its influence in the prognosis of the disease.São apresentados 22 casos de infecção por Nocardia species entre 1977 e 1998, apresentando-se seu quadro clínico e evolução. Todos os pacientes cujos espécimes clínicos mostraram microorganismos sugestivos de Nocardia spp. à coloração de Gram, confirmados posteriormente por cultura, foram incluídos no estudo. Os dados dos pacientes que obtiveram cura foram comparados com aqueles dos pacientes que foram a óbito pelo programa EPIINFO versão 6.04; nível de significância menor que 5% foi considerado estatisticamente significativo. Foram obtidos 22 casos de infecção por Nocardia spp.: seis isolamentos identificados como Nocardia asteroides complex, um como Nocardia asteroides sensu stricto e outro como Nocardia brasiliensis, enquanto os restantes foram identificados como Nocardia spp. Tivemos 17 casos de nocardiose pulmonar (um com disseminação). Tivemos outros quatro casos de nocardiose sistêmica: múltiplos abscessos cerebrais (um); endocardite infecciosa de prótese valvular aórtica (um); nocardiose de intestino delgado (um); abscessos cutâneos múltiplos por Nocardia spp (um). Um paciente apresentou micetoma por Nocardia brasiliensis. Imunossupressão esteve presente em 15 pacientes (68,2%), predominantemente por corticoterapia (93,3%). Nossa mortalidade foi 41%; a mortalidade dos pacientes com nocardiose sistêmica foi de 60%. A nocardiose tem pior prognóstico em pacientes imunossuprimidos e em pacientes com nocardiose sistêmica

Partitioning and purification of polygalacturonases produced by Aspergillus niger URM 5162 using PEG-phosphate in an aqueous two-phase system

Pectinases, or pectinolytic enzymes, are naturally produced by plants, filamentous fungi, bacteria and yeasts. The pectinases are of great importance to clarify and reduce viscosity in fruit juices, improving and increasing tbe filtration efficiency. When used in the crushing of grapes or wine must improve juice extraction, reduce the time to clarify and enhance tbe content ofterpenes in wine. The filamentous fungi most frequently used fur industrial purposes because as much as 90% ofthe enzyme can be excreted into the culture medium. The partitioning and purification of polygalacturonases (PG) produced by Aspergillus niger URM 5162 were investigated in aqueous two-phase systems (ATPS), furmed by polyetbylene glycol and phosphate salts (PE(ijlhosphate). To evaluate the effect oftbe 4 independent variables- molar mass ofpolyetbylene glycol (PEG) (400-8000 g1nol MPEG), PEG concentration (12.5-17.5%, w/w- CPEG), phosphate concentration (15-25%, ...W, CPHOS) and pH (6.0, 8.0) - on the 3 response variables: partition coefficient (K), activity yield (Y) and purification fàctor (PF), a fuctorial design (24) was used. The endo-polygalacturonases (endo-PG) were prefurentially partitioned in tbe top phase. For endo-PG, the highest values for the response variables K, Y and PF of 1.23, 74.04% and 8.18, respectively, were obtained for a CPEG of 12.5% (...W), MPEG of8000 g1nol, and CPHOS of25% (w/w) at pH 6.0. Also, exo-polygalacturonases (exo-PG) were preferentially partitioned in the top phase. ln tbis case, the highest values ofK (2.40), Y (33.33%), and PF (1.98) were obtained with a MPEG of 8000 g1nol, CPEG of 12.5% (...W), and CPHOS of25% (...W) at pH 6.0. ln both cases, MPEG had a positive influence on K, Y and PF. The conditions ofMPEG 8000 g1nol, CPEG of 12.5% (...W), and CPHOS of25% (...W) at pH 6.0 were considered the most suitable for tbe purification of PG produced by A. niger URM 5162. Furtbermore, MPEG and CPHOS were the most important independent variables. The PEG/phosphate system is a useful cost-effective altemative for PG purification

Critical behavior at superconductor-insulator phase transitions near one dimension

I argue that the system of interacting bosons at zero temperature and in random external potential possesses a simple critical point which describes the proliferation of disorder-induced topological defects in the superfluid ground state, and which is located at weak disorder close to and above one dimension. This makes it possible to address the critical behavior at the superfluid-Bose glass transition in dirty boson systems by expanding around the lower critical dimension d=1. Within the formulated renormalization procedure near d=1 the dynamical critical exponent is obtained exactly and the correlation length exponent is calculated as a Laurent series in the parameter \sqrt{\epsilon}, with \epsilon=d-1: z=d, \nu=1/\sqrt{3\epsilon} for the short range, and z=1, \nu=\sqrt{2/3\epsilon}, for the long-range Coulomb interaction between bosons. The identified critical point should be stable against the residual perturbations in the effective action for the superfluid, at least in dimensions 1\leq d \leq 2, for both short-range and Coulomb interactions. For the superfluid-Mott insulator transition in the system in a periodic potential and at a commensurate density of bosons I find \nu=(1/2\sqrt{\epsilon})+ 1/4+O(\sqrt{\epsilon}), which yields a result reasonably close to the known XY critical exponent in d=2+1. The critical behavior of the superfluid density, phonon velocity and the compressibility in the system with the short-range interactions is discussed.Comment: 23 pages, 1 Postscript figure, LaTe

The planet search program at the ESO Coude Echelle spectrometer. III. The complete Long Camera survey results

We present the complete results of the planet search program carried out at the ESO Coude Echelle Spectrometer (CES) on La Silla, using the Long Camera from Nov. 1992 to April 1998. The CES survey has monitored 37 late-type (F8V - M5V) stars in the southern hemisphere for variations in their differential radial velocities (RV) in order to detect Doppler reflex motions caused by planetary companions. This led to the discovery of the first extrasolar planet in an Earth-like orbit around the young (ZAMS) and active G0V star iota Horologii (Kuerster et al. 2000). Here we present the RV results for all survey stars and perform a statistical examination of the whole data-set. Each star is tested for RV variability, RV trends (linear and non-linear) and significant periodic signals. Beta Hyi and eps Ind are identified as long-term, low-amplitude RV variables. Furthermore, for 30 CES survey stars we determine quantitative upper mass-limits for giant planets based on our long-term RV results. We find that the CES Long Camera survey would have detected short-period (51 Peg-type) planets around all 30 stars but no planets with m sin i < 1 M_Jup at orbital separations larger than 2 AU. Finally, we demonstrate that the CES planet search can be continued without applying velocity corrections to the RV results coming from the currently installed Very Long Camera at the CES

Cytogenetical studies in five Atlantic Anguilliformes fishes

The order Anguilliformes comprises 15 families, 141 genera and 791 fish species. Eight families had at least one karyotyped species, with a prevalence of 2n = 38 chromosomes and high fundamental numbers (FN). The only exception to this pattern is the family Muraenidae, in which the eight species analyzed presented 2n = 42 chromosomes. Despite of the large number of Anguilliformes species, karyotypic reports are available for only a few representatives. In the present work, a species of Ophichthidae, Myrichthys ocellatus (2n = 38; 8m+14sm+10st+6a; FN = 70) and four species of Muraenidae, Enchelycore nigricans (2n = 42; 6m+8sm+12st+16a; FN = 68), Gymnothorax miliaris (2n = 42; 14m+18sm+10st; FN = 84), G. vicinus (2n = 42; 8m+6sm+28a; FN = 56) and Muraena pavonina (2n = 42; 6m+4sm+32a; FN = 52), collected along the Northeastern coast of Brazil and around the St Peter and St Paul Archipelago were analyzed. Typical large metacentric chromosomes were observed in all species. Conspicuous polymorphic heterochromatic regions were observed at the centromeres of most chromosomes and at single ribosomal sites. The data obtained for Ophichthidae corroborate the hypothesis of a karyotypic diversification mainly due to pericentric inversions and Robertsonian rearrangements, while the identification of constant chromosome numbers in Muraenidae (2n = 42) suggests a karyotype diversification through pericentric inversions and heterochromatin processes

HFE C282Y and H63D in adults with malignancies in a community medical oncology practice

BACKGROUND: We sought to compare frequencies of HFE C282Y and H63D alleles and associated odds ratios (OR) in 100 consecutive unrelated white adults with malignancy to those in 318 controls. METHODS: Data from patients with more than one malignancy were analyzed according to each primary malignancy. For the present study, OR ≥2.0 or ≤0.5 was defined to be increased or decreased, respectively. RESULTS: There were 110 primary malignancies (52 hematologic neoplasms, 58 carcinomas) in the 100 adult patients. Allele frequencies were similar in patients and controls (C282Y: 0.0850 vs. 0.0896, respectively (OR = 0.9); H63D: 0.1400 vs. 0.1447, respectively (OR = 0.9)). Two patients had hemochromatosis and C282Y homozygosity. With C282Y, increased OR occurred in non-Hodgkin lymphoma, myeloproliferative disorders, and adenocarcinoma of prostate (2.0, 2.8, and 3.4, respectively); OR was decreased in myelodysplasia (0.4). With H63D, increased OR occurred in myeloproliferative disorders and adenocarcinomas of breast and prostate (2.4, 2.0, and 2.0, respectively); OR was decreased in non-Hodgkin lymphoma and B-chronic lymphocytic leukemia (0.5 and 0.4, respectively). CONCLUSIONS: In 100 consecutive adults with malignancy evaluated in a community medical oncology practice, frequencies of HFE C282Y or H63D were similar to those in the general population. This suggests that C282Y or H63D is not associated with an overall increase in cancer risk. However, odds ratios computed in the present study suggest that increased (or decreased) risk for developing specific types of malignancy may be associated with the inheritance of HFE C282Y or H63D. Study of more patients with these specific types of malignancies is needed to determine if trends described herein would remain and yield significant differences