683 research outputs found
Temperature-independent quantum logic for molecular spectroscopy
We propose a fast and non-destructive spectroscopic method for single
molecular ions that implements quantum logic schemes between an atomic ion and
the molecular ion of interest. Our proposal relies on a hybrid coherent
manipulation of the two-ion system, using optical or magnetic forces depending
on the types of molecular levels to be addressed (Zeeman, rotational,
vibrational or electronic degrees of freedom). The method is especially suited
for the non-destructive precision spectroscopy of single molecular ions, and
sets a starting point for new hybrid quantum computation schemes that combine
molecular and atomic ions, covering the measurement and entangling steps.Comment: v3. Substantially enlarged manuscript with details of derivations and
calculations in two appendices. To appear in PR
Strategic investments and multinational firms under oligopoly
We have developed a simple oligopoly model in which foreign direct investment (FDI) decisions are determined in an endogenous fashion. There is a host oligopoly facing competition from a foreign oligopoly in the form of either foreign investment or exports. Then, we propose a multi-stage game to stress the role played by the interactions among foreign rival firms´ decisions, and we identify some of the determinants of a switch from an exporting strategy to an FDI strategy. A delay in the investment is more likely found for big enough country-specific fixed costs and low values of the oligopoly profitability. Our model provides a theoretical basis which leads to predictions in line with previous empirical studies.
Urea y pasta de soya como fuentes de nitrógeno para borregas gestantes
El presente trabajo realizado en el instituto de Investigaciones de Rowett en Aberdeen, Escocia, se llevó a cabo para estudiar el grado de utilización de una fuente de nitrógeno no proteico en comparación con una fuente convencional de proteína ofrecida
Ultracold + collisions in a magnetic field: on the role of the potential energy surface
The collision dynamics of in
the presence of a magnetic field is studied within the close-coupling formalism
in the range between 10 nK and 50 mK. A recent global {\em ab initio} potential
energy surface (PES) is employed and its effect on the dynamics is analyzed and
compared with previous calculations where an experimentally derived PES was
used [New J. Phys {\bf 11}, 055021 (2009)]. In contrast to the results using
the older PES, magnetic field dependence of the low-field-seeking state in the
ultracold regime is characterized by quite a large background scattering
length, , and, in addition, cross sections exhibit broad and pronounced
Feshbach resonances. The marked resonance structure is somewhat surprising
considering the influence of inelastic scattering, but it can be explained by
resorting to the analytical van der Waals theory, where the short range
amplitude of the entrance channel wave function is enhanced by the large
. This strong sensitivity to the short range of the {\em ab initio} PES
persists up to relatively high energies (10 mK). After this study and despite
quantitative predictions are very difficult, it can be concluded that the ratio
between elastic and spin relaxation scattering is generally small, except for
magnetic fields which are either low or close to an asymmetric Fano-type
resonance. Some general trends found here, such as a large density of
quasibound states and a propensity towards large scattering lengths, could be
also characteristic of other anisotropic molecule-molecule systems.Comment: 24 pages, 8 figure
Assessment of periapical status : a comparative study using film-based periapical radiographs and digital panoramic images
Aim: To compare the use of film-based periapical radiographs and digital panoramic images displayed on monitor and glossy paper in the assessment of the periapical status of the teeth. Methodology: A total of 86 subjects were examined. All participants underwent a full-mouth radiographic survey (14 periapical radiographs) and a digital panoramic radiography. The periapical status of all appraised teeth was assessed. Results: Periapical radiographs allowed the assessment of the periapical status of a significantly higher percentage of teeth (87.4%) Digital radiography had a significantly reduced potential to allow assessment of the periapical status (p<0.01). Only 58.0% and 34.3% of teeth could be appraised using digital panoramic images displayed on monitor and glossy paper respectively (p<0.01). The total percentage of teeth with periapical pathosis was four-fold higher when assessed with digital panoramic images displayed on glossy paper compared with periapical radiographs (p<0.01). Conclusions: Periapical radiographs allowed the assessment of a significantly higher percentage of teeth when comparing to digital radiography, which had a significantly lower potency in the assessment of periapical status of the teeth. Digital panoramic images displayed on a monitor resulted in a significantly higher percentage of appraised teeth compared to digital images displayed on glossy paper. Apical periodontitis was scored more often on paper than on screen, and more often on screen than in periapical radiographs
Solvent-assisted in situ synthesis of cysteamine-capped silver nanoparticles
Silver nanoparticles offer a huge potential for biomedical applications owing to their exceptional
properties and small size. Specifically, cysteamine-capped silver nanoparticles could form the
basis for new anticancer therapies combining the cytotoxic effect of the silver core with the
inherent antitumor activity of cysteamine, which inhibit cancer cell proliferation and suppress
invasion and metastasis. In addition, the capability of the cysteamine coating monolayer to
couple a variety of active principles and targeting (bio)molecules of interest proves key to
the tailoring of this platform in order to exploit the pathophysiology of specific tumor types.
Nevertheless, the chain length and conformational flexibility of cysteamine, together with its
ability to attach to the surface of silver nanoparticles via both the thiol and the amine group, have
made the in situ synthesis of these particles an especially challenging task. Herein we report a
solvent-assisted in situ synthesis method that solves this problem. The obtained nanoparticles
have been fully characterized by UV–visible absorption spectroscopy, Fourier transform
infrared spectroscopy, transmission electron microscopy, electron diffraction measurement, high
resolution transmission electron microscopy, scanning transmission electron microscopy, energy
dispersive x-ray spectroscopy nanoanalysis, and dynamic light scattering measurement. Our
synthesis method achieves extremely high yield and surface coating ratio, and colloidal stability
over a wide range of pH values including physiological pH. Additionally, we have demonstrated
that cysteamine-capped nanoparticles obtained by this method can be conjugated to an antibody
for active targeting of the epidermal growth factor receptor, which plays an important role in
the pathogenesis and progression of a wide variety of tumors, and induce cell death in human
squamous carcinoma cells. We believe this method can be readily extended to combinations of
noble metals and longer chain primary, secondary, ternary or even quaternary aminethiolsEspaña, Junta de Andalucía P10- FQM-6615España, Ministerio de Economia y Competitividad CTP2016-80206-
Decoupling music notation to improve end-to-end Optical Music Recognition
Inspired by the Text Recognition field, end-to-end schemes based on Convolutional Recurrent Neural Networks (CRNN) trained with the Connectionist Temporal Classification (CTC) loss function are considered one of the current state-of-the-art techniques for staff-level Optical Music Recognition (OMR). Unlike text symbols, music-notation elements may be defined as a combination of (i) a shape primitive located in (ii) a certain position in a staff. However, this double nature is generally neglected in the learning process, as each combination is treated as a single token. In this work, we study whether exploiting such particularity of music notation actually benefits the recognition performance and, if so, which approach is the most appropriate. For that, we thoroughly review existing specific approaches that explore this premise and propose different combinations of them. Furthermore, considering the limitations observed in such approaches, a novel decoding strategy specifically designed for OMR is proposed. The results obtained with four different corpora of historical manuscripts show the relevance of leveraging this double nature of music notation since it outperforms the standard approaches where it is ignored. In addition, the proposed decoding leads to significant reductions in the error rates with respect to the other cases.This paper is part of the project I+D+i PID2020-118447RA-I00 (MultiScore), funded by MCIN/AEI/10.13039/501100011033. The first author is supported by grant FPU19/04957 from the Spanish Ministerio de Universidades. The second author is supported by grant ACIF/2021/356 from “Programa I+D+i de la Generalitat Valenciana“. The third author is supported by grant APOSTD/2020/256 from “Programa I+D+i de la Generalitat Valenciana”
Biofilm formation of Flavobacterium psychrophilum on various substrates
The ability of Flavobacterium psychrophilum to adhere to and form biofilms on different types of materials used on rainbow trout (Oncorhynchus mykiss) farms was evaluated in this study. F. psychrophilum NCIMB 1947T, was inoculated onto a variety of different surfaces, including stainless steel, plastic, glass, wood, and zinc pyrithione encapsulated antibacterial plastic. The samples were then cultured in a humidified chamber or transferred into fish tanks containing either (1) freshwater or (2) filtered lake water. The formation of biofilms was quantified by fluorescent microscopy. F. psychrophilum formed biofilms on all of the surfaces tested; however, the adherence of the bacterium to the antibacterial plastic was much lower than the attachment observed on the other surfaces, illustrating the bacteriostatic properties of this material for F. psychrophilum. Moreover, bacterial numbers were greater on the surfaces maintained in lake water compared with those maintained in freshwater. The mineral composition of the lake water may have been responsible for the increased bacterial adherence observed between the two types of water. Treatment of the water, regular cleaning of equipment and the use of antimicrobial material to house the fish may help reduce biofilm formation by F. psychrophilum in fish farming systems
Capillary Gas Chromatography-Mass Spectromety (CGC-MS) Analysis and Antioxidant Activities of Phenolic and Components of Guarana and Derivatives
The GC-MS analysis of phenolic compounds present in guarana (Paullinia cupana), an important product of the Amazonian forest consumed in supplements or in soft drinks has been the subject of study. The therapeutic properties and possible protective effects reported for guarana and derivative products could be associated with the antioxidant activity of their phenolics content. The purpose of this study is i) to provide molecular structural information about the composition of guarana in phenolics; ii) to ascertain the effect of solvent type on the extraction procedure; and iii) to determine the antioxidant activity of powders, pericarp, pulp seeds, capsules and bar from Paullinia cupana, as oxygen radical absorbance capacity with fluorescein (ORACFL). Three more phenolic compounds, Quercetin, (+)-Catechin and (-)-Epicatechin have been identified in this report as trimethylsilyl (TMS) derivatives. The amount of total phenolics found in plant materials containing guarana varied from 25.10 to 124.99 mg of gallic acid/g dry sample whereas that the antioxidant activity ranged from 441.5 to 1468.3 μmol TEAC/g dry sample. A high correlation was found between the estimated phenolic contents and the TEAC values (r = 0.937, P < 0.01) for all the types of guarana samples tested
Audit of dental reports (II) : first Phase-II study in a Spanish Faculty of Dentistry
As a measure for correction of deficiencies registered through an audit of dental records in the Comprehensive Dentistry Clinic of the Dentistry Faculty of the University of Seville, we elaborated a new format for dental records which was used in 70 patients, carrying out a monitoring audit (Phase V) by applying the same quality criteria and criteria for data collection used in the initial audit (Phase III). We calculated the indices of fulfilment of 46 quality criteria, extending fulfilment percentage to 41 criteria, while statistically significant differences were found in 25 criteria. The standard prefixed as appropriate (75 %) was reached in 29 criteria (against the 12 criteria in which such standard was reached in the first dental audit). It is essential that faculties of dentistry develop systems for dental record revision which may help students achieve the competence of registering dental-care steps appropriately, teachers identify and give response to educational problems, and clinic administration prevent and correct conflicts, at the same time that they all ensure quality in service provision, ease relations with customers and protect users against legal vulnerability
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