36 research outputs found
Quantum field tomography
We introduce the concept of quantum field tomography, the efficient and
reliable reconstruction of unknown quantum fields based on data of correlation
functions. At the basis of the analysis is the concept of continuous matrix
product states, a complete set of variational states grasping states in quantum
field theory. We innovate a practical method, making use of and developing
tools in estimation theory used in the context of compressed sensing such as
Prony methods and matrix pencils, allowing us to faithfully reconstruct quantum
field states based on low-order correlation functions. In the absence of a
phase reference, we highlight how specific higher order correlation functions
can still be predicted. We exemplify the functioning of the approach by
reconstructing randomised continuous matrix product states from their
correlation data and study the robustness of the reconstruction for different
noise models. We also apply the method to data generated by simulations based
on continuous matrix product states and using the time-dependent variational
principle. The presented approach is expected to open up a new window into
experimentally studying continuous quantum systems, such as encountered in
experiments with ultra-cold atoms on top of atom chips. By virtue of the
analogy with the input-output formalism in quantum optics, it also allows for
studying open quantum systems.Comment: 31 pages, 5 figures, minor change
Quantum state tomography by continuous measurement and compressed sensing
The need to perform quantum state tomography on ever larger systems has
spurred a search for methods that yield good estimates from incomplete data. We
study the performance of compressed sensing (CS) and least squares (LS)
estimators in a fast protocol based on continuous measurement on an ensemble of
cesium atomic spins. Both efficiently reconstruct nearly pure states in the
16-dimensional ground manifold, reaching average fidelities FCS = 0.92 and FLS
= 0.88 using similar amounts of incomplete data. Surprisingly, the main
advantage of CS in our protocol is an increased robustness to experimental
imperfections
Open Data Portal Prototype for the Conservation of Biodiversity of the ‘Universidad Nacional de Loja’
This article describes the possibilities of research and development that exist in the ‘Universidad Nacional de Loja’ (UNL) in the field of biodiversity through the use and exploitation of information and communication technology (ICT) resources. First, the existing methodologies, processes, and initiatives for the publication of open data was explored. Subsequently, a brief description of the biodiversity conservation centers maintained by the UNL was made, highlighting the IT initiatives that have been carried out. Finally, the results of the proposal include the methodology for the release of open data and the creation of the prototype of the biodiversity open data portal of the UNL.
Keywords: programming, open data, biodiversity, botany, artificial intelligenc
Biology, comercial catch and potencial use of tucunare (Cichla monoculus, Pisces: Cichlidae) in Ucayali, Perú
De febrero de 1999 a enero del 2000 se analizaron 250 ejemplares de Cichla monoculus "tucunaré" provenientes de Pucallpa y Yarinacocha, para conocer sus caracterÃsticas biológico pesqueras que conlleven a su adecuado manejo y utilización. Se obtuvo la relación longitud-peso, proporción sexual global, época de desove, talla de madurez y alimentación. La relación Longitud Estándar (LE)-Peso Eviscerado (PE) es isométrica para ambos sexos, hallándose la ecuación conjunta (PE 0,0184*LE3,0963) La proporción sexual global es cercana a 1:1. La época de desove coincide con la creciente del rÃo Ucayali (octubre-enero). La talla de madurez para las hembras es calculada en 26,5 cm de LE, proponiéndose esta talla para el manejo de su pesquerÃa en Ucayali. Su alimentación está constituida principalmente por peces, predominando el orden Characiformes (Cheirodon, Ctenobrycon, Hoplias, Leporinus, Psectrogaster. Se hallan también en la dieta representantes de los órdenes Siluriformes (Corydoras, Hypostominae, Loricariinae, Pimelodidae), Perciformes (Aequidens, Crenicichla) y Gymnotiformes (Stern opygidae), por lo que su actividad alimenticia ocurrirá en horas del dÃa y crepusculares. Se sugiere que C. mococulus sea probado en cultivos, principalmente extensivos, por ser una especie que suele reproducirse en ambientes lénticos, siendo además posible utilizarla como controlador de peces indeseables en estanques, considerando las tallas apropiadas de siembra.Biological characterization of fisheries is essential for an adequate use and management. From February 1999 to January 2000 length-weight ratio, global sexual proportion, egg laying season, mature length, and feeding habit data were recorded from 250 specimens of Cichla monoculus "tucunaré". The standard length (SL) - eviscerated weight (SL-EW) ratio is isometric for both males and females with a joint relation EW = 0,0184* SL 3,0963. Global sexual proportion is near 1:1. Egg laying is during the Ucayali river wet season (October-January). Calculated mature length for females is about 26,5 cm SL and it is proposed as catch length for regulatory purposes. Tucunare feeds mainly from fishes, predominantly median and small Characiformes (Cheirodon. Ctenobrycon, Hoplias, Leporinus and Psectrogaster. But also Siluriformes (Corydoras, Hypostominae, Loricariinae, Pimelodidae), Perciformes (Aequidens, Crenicichla) and Gymnotiformes (Sternopygidae) which suggests that the feeding occurs at daylight and sunset. C. monoculus has potential use for fish farming, specially in extensive method. Coming from lentic environments, it reproduces naturally annually, and can also be used as a fish controller
Identification of genes associated with environmental persistence in Campylobacter jejuni and Campylobacter coli isolates from processing in a broiler abattoir.
The aim of this study was to determine the prevalence of the htrA, htrB and ppk1 genes -all of which are related to environmental persistence- in C. jejuni and C. coli isolates obtained from abattoir samples at the arrival of broilers (initial stage) and in meat products after processing (final stage). A total of 119 DNA extracts (55 C. jejuni and 64 C. coli) were included in the study. Identification of genes was performed by conventional PCR (one for each gene). The overall prevalence was 40.3%, 93.3% and 68.9% for the htrA, htrB and ppk1 genes, respectively. Statistically significant differences were found (p