Chirality in Bare and Passivated Gold Nanoclusters

Chiral structures have been found as the lowest-energy isomers of bare (Au$_{28}$ and Au$_{55}) and thiol-passivated (Au$_{28}(SCH$_{3})$_{16}$and Au$_{38}(SCH_{3})_{24}) gold nanoclusters. The degree of chirality existing in the chiral clusters was calculated using the Hausdorff chirality measure. We found that the index of chirality is higher in the passivated clusters and decreases with the cluster size. These results are consistent with the observed chiroptical activity recently reported for glutahione-passivated gold nanoclusters, and provide theoretical support for the existence of chirality in these novel compounds.Comment: 5 pages, 1 figure. Submitted to PR

Equivalence of two optical quality metrics to predict the visual acuity of multifocal pseudophakic patients

This article studies the relationship between two metrics, the area under the modulation transfer function (MTFa) and the energy efficiency (EE), and their ability to predict the visual quality of patients implanted with multifocal intraocular lenses (IOLs). The optical quality of IOLs is assessed in vitro using two metrics, the MTFa and EE. We measured them for three different multifocal IOLs with parabolic phase profile using image formation, through-focus (TF) scanning, three R, G, B wavelengths, and two pupils. We analyzed the correlation between MTFa and EE. In parallel, clinical defocus curves of visual acuity (VA) were measured and averaged from sets of patients implanted with the same IOLs. An excellent linear correlation was found between the MTFa and EE for the considered IOLs, wavelengths and pupils (R2 > 0.9). We computed the polychromatic TF-MTFa, TF-EE, and derived mathematical relationships between each metrics and clinical average VA. MTFa and EE proved to be equivalent metrics to characterize the optical quality of the studied multifocal IOLs and also in terms of clinical VA predictability

The Second INTEGRAL AGN Catalogue

The INTEGRAL mission provides a large data set for studying the hard X-ray properties of AGN and allows testing of the unified scheme for AGN. We present analysis of INTEGRAL IBIS/ISGRI, JEM-X, and OMC data for 199 AGN supposedly detected by INTEGRAL above 20 keV. The data analysed here allow a significant spectral extraction on 148 objects and an optical variability study of 57 AGN. The slopes of the hard X-ray spectra of Seyfert 1 and Seyfert~2 galaxies are found to be consistent within the uncertainties, whereas higher cut-off energies and lower luminosities are measured for the more absorbed / type 2 AGN. The intermediate Seyfert 1.5 objects exhibit hard X-ray spectra consistent with those of Seyfert 1. When applying a Compton reflection model, the underlying continua appear the same in Seyfert 1 and 2 with photon index 2, and the reflection strength is about R = 1, when assuming different inclination angles. A significant correlation is found between the hard X-ray and optical luminosity and the mass of the central black hole in the sense that the more luminous objects appear to be more massive. There is also a general trend toward the absorbed sources and type 2 AGN having lower Eddington ratios. The black holemass appears to form a fundamental plane together with the optical and X-ray luminosity of the form Lv being proportional to Lx^0.6 M^0.2, similar to that found between radio luminosity Lr, Lx, and M. The unified model for Seyfert galaxies seems to hold, showing in hard X-rays that the central engine is the same in Seyfert 1 and 2, but seen under different inclination angles and absorption. (Abridged)Comment: 26 pages, 16 figures, accepted for publication in A&A. Corrections by language editor included in version

Intermediate deviation regime for the full eigenvalue statistics in the complex Ginibre ensemble

We study the Ginibre ensemble of $N \times N$ complex random matrices and compute exactly, for any finite $N$, the full distribution as well as all the cumulants of the number $N_r$ of eigenvalues within a disk of radius $r$ centered at the origin. In the limit of large $N$, when the average density of eigenvalues becomes uniform over the unit disk, we show that for $0<r<1$ the fluctuations of $N_r$ around its mean value $\langle N_r \rangle \approx N r^2$ display three different regimes: (i) a typical Gaussian regime where the fluctuations are of order ${\cal O}(N^{1/4})$, (ii) an intermediate regime where $N_r - \langle N_r \rangle = {\cal O}(\sqrt{N})$, and (iii) a large deviation regime where $N_r - \langle N_r \rangle = {\cal O}({N})$. This intermediate behaviour (ii) had been overlooked in previous studies and we show here that it ensures a smooth matching between the typical and the large deviation regimes. In addition, we demonstrate that this intermediate regime controls all the (centred) cumulants of $N_r$, which are all of order ${\cal O}(\sqrt{N})$, and we compute them explicitly. Our analytical results are corroborated by precise "importance sampling" Monte Carlo simulations.Comment: 10 pages, 3 Figure

Mesozooplankton community structure during summer months in the bay of Cádiz.

Mesozooplankton organisms (>250 μm) were sampled at two stations (inner and outer Bay) in the Bay of Cádiz between May and July 2008. Samples were analysed by means of a semi-automated technique in order to give a preliminary view of the mesoozooplankton community structure in the Bay, based on taxonomic diversity and biomass distribution among size classes. The abundance of organisms increased from May to July in accordance with the increase in temperature and Chlorophyll a (Chla) concentrations. Abundances were higher in the outer Bay station, where Chla concentrations are greater and the water column is more stable. The community changed from being meroplankton- to holoplankton-based due to an increase of Calanoida and especially Cladocera individuals (mainly Penilia avirostris), which are known to peak acutely in the summer. The analysis of Normalised Biomass-Size spectra revealed fairly steep slopes (average -1.3) and relatively high departures from steady state (r2 = 0.8 – 0.94), expectable in a coastal system such as the Bay of Cádiz were disturbance factors are introduced from benthic and tidal processes, together with anthropogenic pressure

Crustal Thickness Variation Across the Sea of Marmara Region, NW Turkey: A Reflection of Modern and Ancient Tectonic Processes

The Marmara region in Turkey is an important geological setting, both from a tectonic and a seismic hazard/risk perspective. We present a new map of crustal thickness variation across this complex region to better understand the interplay of past and present tectonic processes that have formed present‐day structure. Maps of crustal thickness are created using Ps converted phases and receiver function (RF) analysis of earthquakes recorded at all publicly available seismic stations and stations in the national monitoring network (run by AFAD Disaster and Emergency Management Authority Turkey). RFs are converted from time to depth using a local 3‐D full‐waveform tomographic model and are combined in multiphase common conversion point stacks. Direct P to S converted arrivals and associated multiples are mapped to produce continuous maps of the Moho discontinuity. Results show Moho depths ranging from 26–41 km with a regional trend of westward thinning reflecting the effects of the extensional regime in western Anatolia and the neighboring Aegean Sea. The thinnest crust is observed beneath the western end of the Sea of Marmara, attributed to transtensional basin opening. A distinct region of increased crustal thickness bounded by the West Black Sea Fault in the west, and the northern strand of the North Anatolian Fault in the south, defines the ancient crustal terrane of the Istanbul Zone. Isostatic arguments indicate that the thickened crust and lower elevation in the Istanbul Zone require it to be underlain by thicker lithosphere, a conclusion that is consistent with its hypothesized origin near the Odessa shelf

THE HISTORY OF THE DENTAL SYRINGE

La historia de la odontología debe ser estudiada desde una dimensión amplia para incluir todos los factores, hechos, personajes, teorías, instituciones e instrumental, que posibilitaron la consolidación de la ésta, como una práctica social. Sin embargo, el estudio de la historia del instrumental es un tópico virgen, reseñado de manera muy somera. El propósito de este artículo es presentar una reseña histórica de la jeringa de uso odontológico, toda vez que su historia indica, en alguna medida, la evolución de las teorías sobre la práctica anestésica.[Castro JA, Amaya LJ. Historia de la jeringa odontológica. Ustasalud Odontología 2003; 2: 114 - 118]The history of dentistry should be widely studied. It includes facts, important people, theories, institutions and instruments, that made dentistry important in society. The history of the instruments has not been studied extensively. The purpose of this paper is to show a review about the dental syringe, since it develops the evolution of the anaesthetics

Influencia del vínculo afectivo madre/hijo en el desarrollo de la autonomía de los niños en sutiación de discapaciada de la Fundación Ángeles de Amor, Ibagué Tolima

Tablas, Gráficas, Formatos.El presente proyecto de investigación titulado influencia del vínculo afectivo madre/hijo en el desarrollo de la autonomía de los niños en situación de discapacidad de la fundación ángeles de amor de la ciudad de Ibagué, tuvo como objetivo analizar la influencia del vínculo afectivo madre / hijo en el desarrollo de la autonomía en 23 niños en situación de discapacidad vinculados a la institución antes mencionada. Para ello se realizó un proceso investigativo desde un enfoque cualitativo de tipo descriptivo a través del cual, mediante la aplicación de instrumentos como la entrevista abierta y estructurada, la escala índice de Barthel y la escala de valoración de la autonomía social se lograron identificar los aspectos característicos del vínculo afectivo, reconociendo el nivel de autonomía de los niños en situación de discapacidad de acuerdo con su desarrollo físico y cognitivo; así mismo se logró describir cómo el desarrollo de la autonomía incide en el proceso de inserción social de los niños. El análisis de resultados permitió evidenciar que el tipo de vínculo desarrollado entre una madre y un hijo incide directamente en el proceso de autonomía personal y social de este último, el cual se caracteriza por ser seguro, ambivalente o evitativo y que desde una concepción amplia del vínculo este se refleja en las conductas, formas de relación, actitudes y comportamiento de los niños dentro de su contexto social específico. En ese sentido, como producto del ejercicio investigativo se presenta una propuesta de intervención a través de la cual se pretende el fortalecimiento del vínculo seguro madre/hijo y como consecuencia de este el desarrollo de la autonomía acorde con las posibilidades de cada participante para lo cual se toma como punto departida cada una de las situaciones de discapacidad de los participantes.This research project influence the bonding between mother / child in developing the autonomy of disabled children at the foundation of love angels city of Ibague, aimed to analyze the influence of bonding between mother / son in the development of autonomy in 23 disabled children at the institution linked above. This was achieved by an investigative process from a descriptive qualitative approach by which, through the application of tools such as the open interview, scale and Barthel index rating scale social autonomy is able to identify the characteristic features of bonding, recognizing the level of autonomy of children with disabilities according to their physical and cognitive development, likewise was achieved describe how the development of autonomy affects the social integration process of children. The analysis of results allowed noting the type of bond developed between a mother and a child directly affects the process of personal and social autonomy of the latter, which is known for being secure, ambivalent or avoidant and from a broad conception of link this is reflected in the behaviors, ways of relating, attitudes and behavior of children within their specific social context. In that sense, as a product of research exercise presents a proposal of intervention through which it seeks to secure bond strengthening mother / son and as a result of this the development of autonomy according to the capabilities of each participant for which is taken as departida each disability situations participants

Innovative acrylic thermoplastic composites versus conventional composites: Improving the impact performances

This study focuses on the benefits to the mechanical performance against impact loading offered by glass fiber reinforced (GFR) acrylic thermoplastic polymers, based on new room temperature cure methyl-methacrylate (MMA) matrix. Glass fiber reinforcement is a common solution for a wide variety of engineering applications based on thermoset matrices. However, its use presents some disadvantages such as adequate control of manufacturing temperature, problematic recycling and low damage tolerance. In contrast, acrylic polymers presents a high potential as an alternative matrix for thermoset composites due to their superior mechanical properties, manufacturing at low temperatures and recycled possibilities. In order to compare the mechanical behavior under impact loading of acrylic thermoplastic composites versus conventional composites, Charpy impact test and low velocity impact tests are carried out. The GFR acrylic laminate composites considered are compared to conventional composites manufactured with epoxy and polyester resins in terms of impact resistance and damage evolution. This study covers an impact energy rate from 10 to 60 J and analyses the maximum load, deflection, absorbed energy and associated damage, showing a better performance of the new GPR. acrylic thermoplastic polymers with respect to conventional GFR composites