2,986 research outputs found
Deterministic generation of large-scale entangled photonic cluster state from interacting solid state emitters
The ability to create large highly entangled `cluster' states is crucial for
measurement-based quantum computing. We show that deterministic multi-photon
entanglement can be created from coupled solid state quantum emitters without
the need for any two-qubit gates and regardless of whether the emitters are
identical. In particular, we present a general method for controlled
entanglement creation by making direct use of the always-on exchange
interaction, in combination with single-qubit operations. This is used to
provide a recipe for the generation of two-dimensional, cluster-state entangled
photons that can be carried out with existing experimental capabilities in
quantum dots
Fault-tolerance thresholds for the surface code with fabrication errors
The construction of topological error correction codes requires the ability
to fabricate a lattice of physical qubits embedded on a manifold with a
non-trivial topology such that the quantum information is encoded in the global
degrees of freedom (i.e. the topology) of the manifold. However, the
manufacturing of large-scale topological devices will undoubtedly suffer from
fabrication errors---permanent faulty components such as missing physical
qubits or failed entangling gates---introducing permanent defects into the
topology of the lattice and hence significantly reducing the distance of the
code and the quality of the encoded logical qubits. In this work we investigate
how fabrication errors affect the performance of topological codes, using the
surface code as the testbed. A known approach to mitigate defective lattices
involves the use of primitive SWAP gates in a long sequence of syndrome
extraction circuits. Instead, we show that in the presence of fabrication
errors the syndrome can be determined using the supercheck operator approach
and the outcome of the defective gauge stabilizer generators without any
additional computational overhead or the use of SWAP gates. We report numerical
fault-tolerance thresholds in the presence of both qubit fabrication and gate
fabrication errors using a circuit-based noise model and the minimum-weight
perfect matching decoder. Our numerical analysis is most applicable to 2D
chip-based technologies, but the techniques presented here can be readily
extended to other topological architectures. We find that in the presence of 8%
qubit fabrication errors, the surface code can still tolerate a computational
error rate of up to 0.1%.Comment: 10 pages, 15 figure
Otroacizzia soriae sp. nov., a new Miocene psyllid (Insecta, Hemiptera, Psyllidae) from Dominican amber
new species of the fossil genus Otroacizzia Klimaszewski, 1996 (Hemiptera, Psyllidae) is described as Otroacizzia soriae sp. nov. on the basis of a female specimen. This species is preserved in mid-Miocene amber from La Toca mines, Dominican Republic. The genus Otroacizzia is the most diverse psylloid genus in Dominican amber, with four known species. The new species differs from the three previously known species by the presence of a subapical dark band in the fore wing from the anterior part of the end of vein Rs to the end of vein Cu1b, which has a gap in the middle of the cell c1. Other differences in the fore wing are the presence of a strongly curved vein Cu1b and a cell c1 clearly longer than cell m1. Finally, the antennal segment 3 of the new species is one and a half times longer than segment 4.Se describe una nueva especie del género fósil Otroacizzia Klimaszewski, 1996 (Hemiptera, Psyllidae) a partir de un ejemplar hembra: Otroacizzia soriae sp. nov. Esta especie está conservada en ámbar del Mioceno medio de las minas de La Toca en República Dominicana. Con cuatro especies conocidas, el género Otroacizzia es el género de psiloideo con mayor diversidad en el ámbar dominicano. La nueva especie difiere de las tres especies ya conocidas por la presencia de una banda oscura subapical en el ala anterior desde la parte anterior del final de la vena Rs hasta el final de la vena Cu1b, la cual presenta una discontinuidad en el medio de la celda c1. Otras diferencias en el ala anterior son la presencia de una vena Cu1b fuertemente curvada y una celda c1 claramente más larga que la celda m1. Finalmente, el tercer segmento antenal de la nueva especie es una vez y media más largo que el cuarto segmento
The economic value of information provided by milk biomarkers under different scenarios : case-study of an ex-ante analysis of fat-to-protein ratio and fatty acid profile to detect subacute ruminal acidosis in dairy cows
Monitoring systems (MS) provide additional information that many developers and researchers expect will reduce the uncertainty surrounding decision-making in livestock production and therefore enhance management decisions. However, the actual economic value of the information (VoI) yielded by MS has hardly been investigated. The aim of this study was to fill that void based on two objectives. The first is to estimate the VoI of MS prior to implementation using decision analysis based on scarce data from different sources. The second objective is to identify which factors most influence the VoI of MS and to develop recommendations about the focus of future MS development. To illustrate our objectives, we used a case study of two milk biomarkers used to monitor subacute ruminal acidosis (SARA) in dairy cows: fat-to-protein ratio (FPR) and the fatty acid profile (FAP). FPR is presently used to monitor SARA, while FAP is a newly developed test, currently in the pre-commercial phase, with reports of better accuracy than FPR. A stochastic decision tree model was used to estimate the expected monetary value of three levels of information with regards to SARA: (i) no monitoring, monitoring (ii) with FPR or (iii) with FAP. The VoI of FPR and FAP were calculated as the difference in expected monetary value of monitoring with FPR and FAP as compared with no monitoring, respectively. Several scenarios were modeled using sensitivity and elasticity analyses. The aim was not only to compensate for the scarcity of data for some variables, but also to identify under which conditions decisions based on FAP monitoring were indeed the best. In all the scenarios, monitoring SARA with FPR had the lowest expected monetary value. No monitoring was a better decision in 70% of the iterations in the scenario that described the most probable situation. The VoI of FAP was positive when SARA prevalence was between 0.21 and 0.79 with its maximum value at 0.61, when the treatment costs were lower than (sic)116/case/year and when the disease costs were higher than (sic)260/case/year. Moreover, an increase of specificity of the FAP to 0.95 yielded a positive VoI, whereas an increase of its sensitivity to 1.0 still yielded a negative VoI, suggesting that developers of the FAP should focus on improving its specificity rather than its sensitivity. To avoid suboptimal use of finite resources while developing MS, we recommend ex-ante investigation of the VoI of the MS under development
A heuristic approach to the decision-making process of energy prosumers in a circular economy
Renewable distributed energy and self-consumption are promising and sustainable solutions in the energy-transition scenario for moving toward a circular economy. In this future scheme, prosumers are expected to play a leading role in the forthcoming sustainable energy market, facing new technical, economic, and financial challenges as energy producers at a small scale. In fact, the adoption of photovoltaic (PV) self-consumption systems requires mobilizing capital for investment and their interaction with the market. In this scenario, the aim of this paper was to explore insights into the decision-making process of prosumers to enhance the understanding of self-consumption deployment and to support effective policymaking. This study contributes to the state of the art by defining and classifying determinants of the energy prosumers’ decision-making process and their relevance using a heuristic approach. Potential measuring tools and methods are analyzed through a specific case study of Spanish prosumers
A Lagrangian analysis of the variation in moisture sources related to drier and wetter conditions in regions around the Mediterranean Basin
Here, we describe our use of the Lagrangian 3-D FLEXPART model to investigate the variation in sources of moisture related to the drier and wetter conditions of the different regions that surround the Mediterranean Basin. We carried out seasonal analyses for the period from March 2000 to February 2005, and identified those years with the highest and lowest rates of precipitation by season, averaged over eight different continental regions. The variation in specific humidity along the 10-day backward trajectories of the particles identified over the target areas was tracked for the selected period, and the characteristics of the moisture sources were then compared between wetter and drier conditions by season. Although they only represented a relatively short period, the results suggest that in most of the years chosen, the moisture sources were more extensive and/or more intense during wetter periods. The contribution of the north Atlantic as a source of moisture is apparent for the Iberian Peninsula, for France and for Central North Africa. Otherwise, the Mediterranean Sea is the predominant source for Eastern North Africa, and for the Italian and Balkan Peninsulas. Local sources provide moisture for the Eastern Mediterranean and Western North Africa
Accidental poisoning with Wedelia glauca (“sunchillo”) in a bull confirmed by analysis of rumen content
Wedelia glauca is an invasive, perennial plant of the Asteraceae family native to South America. Its toxicity is attributed to the presence of a hepatotoxic terpenoid known as atractyloside, a powerful inhibitor of cellular respiration and ATP synthesis. Cattle are the most frequently poisoned species, and the course of this poisoning is hyperacute or acute. Occasionally, it is possible to find fragments of plants in the rumen contents and indentify the dermis structure of the plants, as they do not undergo significant changes in spite of the mechanic and enzymatic activities occurring in the rumen. The macroscopic and microscopic anatomopathologic findings of a natural Wedelia glauca poisoning case in a Hereford bull are reported. It was confirmed by micrographic analysis of plant fragments found in the rumen contents and also in bales used to feed those animals
Quality of life after upper third molar removal : a prospective longitudinal study
Third molar extraction is a very common procedure in Dentistry. The aim of this study was to evaluate the quality of life (QoL) and satisfaction of patients undergoing extraction of an upper third molar under local anesthesia. A second objective was to describe the evolution of self-reported pain measured in a visual analogue scale (VAS) in the 7 days after surgery and its relationship with pre- and intraoperative factors. A prospective longitudinal cohort study was made. Fifty-five patients received a questionnaire assessing social and working isolation, eating and speaking ability, diet modifications, sleep impairment, physical appearance, discomfort at suture removal and overall satisfaction. Pain was registered daily on a VAS scale. A descriptive and bivariate analysis of the data was performed. Forty-seven patients were included. Pain decreased lineally across the 7 days, and relief was significant between days 2 and 3. Intraoperative complications were significantly associated with pain. The complication that showed the highest pain score was the tuberosity fracture. Upper third molar removal significantly affects the patient?s quality of life, particularly during the first 2 days after extraction
Análisis de la pervivencia, difusión y productividad de la revista Ars Pharmaceutica
The primary objective of this work was to study the bibliometric indicators of survival, circulation and productivityof the pharmaceutical magazine Ars Pharmaceutica, up until the year 2003. Numerous revisions of periodical publicationdirectories ISSN (International Standard Serial Number, ULRICH’S (Periodicals Directory), and the UniversalClassifi cations Decimal, together with specialised national and international data bases were consulted. The data basesof an international nature included IPA (International Pharmaceutical Abstracts), SCI Expanded (Science Citation IndexExpanded), MEDLINE (Index Medicus), EMBASE (Excerpta Medica), BIOSIS PREVIEWS, ANALYTICAL ABSTRACTS,FSTA (Food Science and Technology Abstracts), SCIFINDER ACHOLAR and CITATION INDEX, while those fallingwithin a national sphere included the IME (Indice Medico Español) Spanish Medical Index and the ICYT, (ÍndiceEspañol de Ciencia y Tecnología) Spanish Science and Technology index. Appropriate search strategy techniques wereemployed in the retrieval of the data in all of the data bases consulted. According to the results obtained, analysis ofthe data base information available shows that Ars Pharmaceutica, with 43 years of existence can be considered asan well accepted journal of considerable dissemination, occupying a preferential position, in comparison with othersjournals of the same discipline.El objetivo principal de este trabajo es el estudio de algunos de los indicadores bibliométricos de la revista ArsPharmaceutica hasta el año 2003, tales como la pervivencia, circulación y productividad; para ello se han efectuadorevisiones en los directorios de publicaciones periódicas ISSN (International Standard Serial Number / Número InternacionalNormalizado de Publicaciones Seriadas), el ULRICH’S (Periodicals Directory), y la CDU (Clasifi cación DecimalUniversal), así como en bases de datos especializadas, nacionales e internacionales; como nacionales, el IME (Índice Médico Español) e ICYT (Índice Español de Ciencia y Tecnología) y como internacionales el IPA (InternationalPharmaceutical Abstracts), SCI Expanded (Science Citation Index Expanded), MEDLINE (Index Medicus), EMBASE (ExcerptaMedica), BIOSIS PREVIEWS, ANALYTICAL ABSTRACTS, FSTA (Food Science and Technology Abstracts),SCIFINDER SCHOLAR y CHEMISTRY CITATION INDEX, empleándose la adecuada estrategia de búsqueda pararecuperar la información en cada una de las bases de datos utilizada. Según los resultados obtenidos, se puede considerarque la Ars Pharmaceutica, con 43 años de vigencia y una notable difusión en las bases de datos analizadas,ocupa un lugar preferente entre las revistas científi cas de su misma disciplina
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