1,477 research outputs found
Measuring Entanglement in a Photonic Embedding Quantum Simulator
Measuring entanglement is a demanding task that usually requires full
tomography of a quantum system, involving a number of observables that grows
exponentially with the number of parties. Recently, it was suggested that
adding a single ancillary qubit would allow for the efficient measurement of
concurrence, and indeed any entanglement monotone associated to antilinear
operations. Here, we report on the experimental implementation of such a
device---an embedding quantum simulator---in photonics, encoding the entangling
dynamics of a bipartite system into a tripartite one. We show that bipartite
concurrence can be efficiently extracted from the measurement of merely two
observables, instead of fifteen, without full tomographic information.Comment: Updated versio
Histologic and Histomorphometric Analysis of Posterior Region of the Human Temporomandibular Disc
Objective The aim of this study was to analyze histologic and histomorphometric features of the articular disc in groups with and without disc displacement. Study design A sample of 39 temporomandibular joints TMJs (31 case specimens, 8 control specimens) from 28 patients (mean age 31.2 years) were recruited for this study. The patients were considered to be affected and treated surgically with disc repositioning when presenting painful clinical signs of disc displacement after unsuccessful nonsurgical treatment for at least 6 months. Of the control patients, 4 presented condyle fracture which required opening to be reduced for treatment, and 4 displayed active condyle hyperplasia. The posterior region of the disc was removed and sent for histologic and histomorphometric analysis. Histologic (hematoxylin-eosin) and histomorphometric (picro-Sirius red) analyses were performed. Statistically significant differences between the analyzed groups were accessed through the chi-squared test (P ≤ .05). The Mann-Whitney U test was used to observe the differences between mean values when variables did not present normal distribution [Kolmogorov-Smirnov(a) test]. Results There were no significant differences between the groups in relation to the parameters studied by histologic and histomorphometric analysis (using or not using polarization). Conclusions To the limits of this study, there were no significant histologic and histomorphometric differences in the articular disc between groups with and without TMJ dysfunction
Building the what and where systems: multi-scale lines, edges and keypoints
Computer vision for realtime applications requires tremendous computational
power because all images must be processed from the first to the last pixel. Ac
tive vision by probing specific objects on the basis of already acquired context
may lead to a significant reduction of processing. This idea is based on a few
concepts from our visual cortex (Rensink, Visual Cogn. 7, 17-42, 2000): (1) our
physical surround can be seen as memory, i.e. there is no need to construct
detailed and complete maps, (2) the bandwidth of the what and where systems
is limited, i.e. only one object can be probed at any time, and (3) bottom-up,
low-level feature extraction is complemented by top-down hypothesis testing, i.e.
there is a rapid convergence of activities in dendritic/axonal connections
Occurrence of Panstrongylus guentheri Berg (Hemiptera: Reduviidae) in Mato Grosso do Sul State, Brazil
Relata-se a primeira ocorrência de Panstrongylus guentheri Berg no Brasil. Essa espécie, até então, havia sido observada somente na Argentina, Paraguai, BolÃvia e Uruguai. Desta feita, amplia-se a distribuição geográfica desse Triatominae por meio de dois exemplares capturados nos municÃpios de Bodoquena e Itaporã, ambos no Mato Grosso do Sul. Esses exemplares estavam em ambiente intradomiciliarThe first occurrence of Panstrongylus guentheri Berg in Brazil is presented. This species had been reported only in the territories of Argentina, Paraguay, Bolivia and Uruguay. We have extended the geographic distribution of this Triatominae, with two specimens captured in Bodoquena and Itaporã cities, both in Mato Grosso do Sul State, Brazil. These specimens were found in the intradomestic environmen
Reservoir engineering with arbitrary temperatures for spin systems and quantum thermal machine with maximum efficiency
Abstract Reservoir engineering is an important tool for quantum information
science and quantum thermodynamics since it allows for preparing and/or
protecting special quantum states of single or multipartite systems or to
investigate fundamental questions of the thermodynamics as quantum thermal
machines and their efficiencies. Here we employ this technique to engineer
reservoirs with arbitrary (effective) negative and positive temperatures for a
single spin system. To this end, we firstly engineer an appropriate interaction
between a qubit system, a carbon nuclear spin, to a fermionic reservoir, in our
case a large number of hydrogen nuclear spins that acts as the spins bath. This
carbon-hydrogen structure is present in a polycrystalline adamantane, which was
used in our experimental setup. The required interaction engineering is
achieved by applying a specific sequence of radio-frequency pulses using
Nuclear Magnetic Resonance (NMR), while the temperature of the bath can be
controlled by appropriate preparation of the initial hydrogen nuclear spin
state, being the predicted results in very good agreement with the experimental
data. As an application we implemented a single qubit quantum thermal machine
which operates at a single reservoir at effective negative temperature whose
efficiency is always 100%, independent of the unitary transformation performed
on the qubit system, as long as it changes the qubit state.Comment: 7 pages, 6 figure
Exact Solution of an Evolutionary Model without Ageing
We introduce an age-structured asexual population model containing all the
relevant features of evolutionary ageing theories. Beneficial as well as
deleterious mutations, heredity and arbitrary fecundity are present and managed
by natural selection. An exact solution without ageing is found. We show that
fertility is associated with generalized forms of the Fibonacci sequence, while
mutations and natural selection are merged into an integral equation which is
solved by Fourier series. Average survival probabilities and Malthusian growth
exponents are calculated indicating that the system may exhibit mutational
meltdown. The relevance of the model in the context of fissile reproduction
groups as many protozoa and coelenterates is discussed.Comment: LaTeX file, 15 pages, 2 ps figures, to appear in Phys. Rev.
Reconfigurable silicon thermo-optical ring resonator switch based on Vernier effect control
A proof-of-concept for a new and entirely CMOS compatible
thermo-optic reconfigurable switch based on a coupled ring resonator structure is experimentally demonstrated in this paper. Preliminary results show that a single optical device is capable of combining several functionalities, such as tunable filtering, non-blocking switching and
reconfigurability, in a single device with compact footprint (~50μm x 30μm)
ToxocarÃase humana: inquérito soroepidemiológico no municÃpio de Campinas (SP), Brasil
The occurrence of human Toxocara infection was evaluated in three neighborhoods of the periphery of the Campinas municipality (Jardim Santa Mônica, Jardim São Marcos and Jardim Campineiro) in 1999. Forty residences and 138 residents were randomly selected by drawing lots and were submitted to a seroepidemiological survey, which included blood collection for the immunoenzymatic detection (ELISA) of anti-Toxocara antibodies and a blood count, and the application of a semi-structured questionnaire for the evaluation of epidemiological data. Significant levels of anti-Toxocara antibodies were detected in 23.9% of the 1999 samples. No significant difference in the frequency of infection according to age was observed. Environmental contamination with Toxocara eggs was observed in 12.3 and 14.0% of 57 soil samples collected in the same region in December 1998 and July 1999, respectively. Univariate analysis and multiple logistic regression of the data obtained from the questionnaires and of the results of the serological tests, suggest a significant influence of socioeconomic variables on the frequency of human infection with Toxocara under the conditions prevalent in the study area.Estudou-se a ocorrência de infecção humana por Toxocara em três bairros da periferia do municÃpio de Campinas (Jardim Santa Mônica, Jardim São Marcos e Jardim Campineiro). Em 1999 sortearam-se aleatoriamente 40 domicÃlios e 138 moradores foram submetidos a inquérito soroepidemiológico, que incluiu coleta de sangue para teste imunoenzimático (E.L.I.S.A.) visando pesquisa de anticorpos anti-Toxocara e hemograma, além de aplicação de questionário semi-estruturado para avaliação de dados de interesse epidemiológico. Observou-se presença de anticorpos anti-Toxocara em 23,9% das amostras, sem ocorrência de diferença significativa quando se considerou a idade ou sexo dos indivÃduos examinados. Em 57 amostras de solo da mesma região, coletadas em dezembro de 1998 e novamente em julho de 1999, estudou-se a contaminação ambiental por ovos de Toxocara, verificando-se sua presença em, respectivamente, 12,3% e 14,0% das amostras. Análises univariada e multivariada por regressão logÃstica dos dados obtidos a partir dos questionários e dos resultados da sorologia anti-Toxocara mostraram influência significativa de variáveis de ordem sócio-econômica na prevalência de infecção humana por Toxocara, nas condições presentes na área estudada
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