Albedos of Main-Belt Comets 133P/Elst-Pizarro and 176P/LINEAR

We present the determination of the geometric R-band albedos of two main-belt comet nuclei based on data from the Spitzer Space Telescope and a number of ground-based optical facilities. For 133P/Elst-Pizarro, we find an albedo of p_R=0.05+/-0.02 and an effective radius of r_e=1.9+/-0.3 km (estimated semi-axes of a~2.3 km and b~1.6 km). For 176P/LINEAR, we find an albedo of p_R=0.06+/-0.02 and an effective radius of r_e=2.0+/-0.2 km (estimated semi-axes of a~2.6 km and b~1.5 km). In terms of albedo, 133P and 176P are similar to each other and are typical of other Themis family asteroids, C-class asteroids, and other comet nuclei. We find no indication that 133P and 176P are compositionally unique among other dynamically-similar (but inactive) members of the Themis family, in agreement with previous assertions that the two objects most likely formed in-situ. We also note that low albedo (p_R<0.075) remains a consistent feature of all cometary (i.e., icy) bodies, whether they originate in the inner solar system (the main-belt comets) or in the outer solar system (all other comets).Comment: 11 pages, 3 figures, accepted for publication in ApJ

μ-calpain binds to lipid bilayers via the exposed hydrophobic surface of its Ca2+-activated conformation

μ- and m-calpain are cysteine proteases requiring micro- and millimolar Ca2+ concentrations for their activation in vitro. Among other mechanisms, interaction of calpains with membrane phospholipids has been proposed to facilitate their activation by nanomolar {[}Ca2+] in living cells. Here the interaction of non-autolysing, C115A active-site mutated heterodimeric human μ-calpain with phospholipid bilayers was studied in vitro using protein-to-lipid fluorescence resonance energy transfer and surface plasmon resonance. Binding to liposomes was Ca2+-dependent, but not selective for specific phospholipid. head groups. {[}Ca2+](0.5) for association with lipid bilayers was not lower than that required for the exposure of hydrophobic surface (detected by TNS fluorescence) or for enzyme activity in the absence of lipids. Deletion of domain V reduced the lipid affinity of the isolated small subunit (600-fold) and of the heterodimer (10- to 15-fold), thus confirming the proposed role of domain V for membrane binding. Unexpectedly, mutations in the acidic loop of the `C2-like' domain III, a putative Ca2+ and phospholipid-binding site, did not affect lipid affinity. Taken together, these results support the hypothesis that in vitro membrane binding of μ-calpain is due to the exposed hydrophobic surface of the active conformation and does not reduce the Ca2+ requirement for activation

μ-calpain binds to lipid bilayers via the exposed hydrophobic surface of its Ca2+-activated conformation

μ- and m-calpain are cysteine proteases requiring micro- and millimolar Ca2+ concentrations for their activation in vitro. Among other mechanisms, interaction of calpains with membrane phospholipids has been proposed to facilitate their activation by nanomolar {[}Ca2+] in living cells. Here the interaction of non-autolysing, C115A active-site mutated heterodimeric human μ-calpain with phospholipid bilayers was studied in vitro using protein-to-lipid fluorescence resonance energy transfer and surface plasmon resonance. Binding to liposomes was Ca2+-dependent, but not selective for specific phospholipid. head groups. {[}Ca2+](0.5) for association with lipid bilayers was not lower than that required for the exposure of hydrophobic surface (detected by TNS fluorescence) or for enzyme activity in the absence of lipids. Deletion of domain V reduced the lipid affinity of the isolated small subunit (600-fold) and of the heterodimer (10- to 15-fold), thus confirming the proposed role of domain V for membrane binding. Unexpectedly, mutations in the acidic loop of the `C2-like' domain III, a putative Ca2+ and phospholipid-binding site, did not affect lipid affinity. Taken together, these results support the hypothesis that in vitro membrane binding of μ-calpain is due to the exposed hydrophobic surface of the active conformation and does not reduce the Ca2+ requirement for activation

Electronic and structural distortions in graphene induced by carbon vacancies and boron doping

We present an ab initio study on the structural and electronic distortions of modified graphene by creation of vacancies, inclusion of boron atoms, and the coexistence of both, by means of thermodynamics and band structure calculations. In the case of coexistence of boron atoms and vacancy, the modified graphene presents spin polarization only when B atoms locate far from vacancy. Thus, when a boron atom fills single- and di-vacancies, it suppresses the spin polarization of the charge density. In particular when B atoms fill a di-vacancy a new type of rearrangement occurs, where a stable BC4 unit is formed inducing important out of plane distortions to graphene. All these findings suggest that new chemical modifications to graphene and new type of vacancies can be used for interesting applications such as sensor and chemical labeling.Comment: 22 pages, 9 figures and 3 table

Albedos of Small Jovian Trojans

We present thermal observations of 44 Jovian Trojan asteroids with diameters (D) ranging from 5 to 24 km. All objects were observed at a wavelength of 24 microns with the Spitzer Space Telescope. Measurements of the thermal emission and of scattered optical light, mostly from the University of Hawaii 2.2-meter telescope, together allow us to constrain the diameter and geometric albedo of each body. We find that the median R-band albedo of these small Jovian Trojans is about 0.12, much higher than that of "large" Trojans with D > 57 km (0.04). Also the range of albedos among the small Trojans is wider. We attribute the Trojan albedos to an evolutionary effect: the small Trojans are more likely to be collisional fragments and so their surfaces would be younger. A younger surface means less cumulative exposure to the space environment, which suggests that their surfaces would not be as dark as those of the large, primordial Trojans. In support of this hypothesis is a statistically significant correlation of higher albedo with smaller diameter in our sample alone and in a sample that includes the larger Trojans.Comment: 41 pages, 6 figures, 4 tables, AASTe

A Method to Determine the In-Air Spatial Spread of Clinical Electron Beams

We propose and analyze in detail a method to measure the in-air spatial spread parameter of clinical electron beams. Measurements are performed at the center of the beam and below the adjustable collimators sited in asymmetrical configuration in order to avoid the distortions due to the presence of the applicator. The main advantage of our procedure lies in the fact that the dose profiles are fitted by means of a function which includes, additionally to the Gaussian step usually considered, a background which takes care of the dose produced by different mechanisms that the Gaussian model does not account for. As a result, the spatial spread is obtained directly from the fitting procedure and the accuracy permits a good determination of the angular spread. The way the analysis is done is alternative to that followed by the usual methods based on the evaluation of the penumbra width. Besides, the spatial spread found shows the quadratic-cubic dependence with the distance to the source predicted by the Fermi-Eyges theory. However, the corresponding values obtained for the scattering power are differing from those quoted by ICRU nr. 35 by a factor ~2 or larger, what requires of a more detailed investigation.Comment: 11 pages, 5 Postscript figures, to be published in Medical Physic

Approximation of integration maps of vector measures and limit representations of Banach function spaces

[EN] We study whether or not the integration maps of vector measures can be computed as pointwise limits of their finite rank Radon¿Nikodým derivatives. The positive cases are obtained by using the circle of ideas related to the approximation property for Banach spaces. The negative ones are given by means of an appropriate use of the Daugavet property. As an application, we analyse when the norm in a space L 1 (m) of integrable functions can be computed as a limit of the norms of the spaces of integrable functions with respect to the Radon¿Nikodým derivatives of m.E. Jiménez Fernández was supported by Junta de Andalucía and FEDER (grant no. P09-FQM-4911 (Spain)) and by Ministerio de Economía, Industria y Competitividad (grant no. MTM2012-36740-C02- 02 (Spain)). E. A. Sánchez Pérez was supported by Ministerio de Economía, Industria y Competitividad (grant no. MTM2016-77054-C2-1-P (Spain)).Jiménez Fernández, E.; Sánchez Pérez, EA.; Werner, D. (2017). Approximation of integration maps of vector measures and limit representations of Banach function spaces. Annales Polonici Mathematici. 120(1):63-81. https://doi.org/10.4064/ap170407-21-9S6381120

A Computationally Efficient Method for Simulating Metal-Nanowire Dipole Antennas at Infrared and Longer Visible Wavelengths

This paper presents a numerically efficient approach for simulating nanowires at infrared and long optical wavelengths. A computationally efficient circuit-equivalent modeling approach based on the electric-field integral-equation (EFIE) formulation is employed to simulate the highly dispersive behavior of nanowires at short wavelengths. The proposed approach can be used both for frequency-domain and for time-domain EFIE formulations. In comparison with widely used full-wave solutions achieved through the finite-difference time-domain method, the circuit-based EFIE formulation results in a sharp reduction of the computational resources while retaining high accuracy.This work was supported in part by the Spanish Ministry of Education under Project PR2009-0443, in part by the Penn State MRSEC under NSF Grant 0213623, in part by the EU FP7/2007-2013 under Grant GA 205294 (HIRF SE project), in part by the Spanish National Projects TEC2010-20841- C04-04, CSD200800068, and DEX-5300002008105, and in part by the Junta de Andalucia Project P09-TIC5327

Una teràpia per a la bulímia

Un estudi realitzat per un equip de l'Hospital Universitari de Bellvitge, dirigit pel Dr. Fernando Fernández-Aranda i analitzat per les professores Roser Granero i Eva Penelo del Departament de Psicobiologia i de Metodologia de la Ciències de la Salut de la UAB, ha aprofundit en com la teràpia cognitiva-conductual en pacients que pateixen un trastorn de la conducta alimentària permet reduir els símptomes depressius de les afectades. El treball mostra com aquest tipus de tractament, amb una actitud positiva, permet modificar trets de caràcter que en principi estan considerats genèticament determinats.Un estudio realizado por un equipo del Hospital Universitario de Bellvitge, dirigido por el Dr. Fernando Fernández-Aranda y analizado por las profesoras Roser Granero y Eva Penelo del Departamento de Psicobiología y Metodología de la Ciencias de la Salud de la UAB, ha profundizado en cómo la terapia cognitiva-conductual en pacientes que padecen un trastorno de la conducta alimentaria permite reducir los síntomas depresivos de las afectadas. El trabajo muestra cómo este tipo de tratamiento, con una actitud positiva, permite modificar rasgos de carácter que en principio están considerados genéticamente determinados

Videojocs per tractar trastorns mentals

Un videojoc, anomenat Island, dissenyat i desenvolupat per un equip multidisciplinari de clínics, enginyers i programadors, del que forma part l'Hospital Universitari de Bellvitge i en el qual hi col·laboren les professores Roser Granero i Eva Penelo de la UAB, sembla permetre a pacients amb malalties mentals adquirir noves estratègies per afrontar-se a les pròpies emocions negatives en situacions estressants de la vida quotidiana. Aquests pacients també senten que utilitzant aquest videojoc participen més activament en el seu procés de recuperació. Així, els videojocs apareixen amb un futur prometedor com a complement a tractaments tradicionals d'aquestes malalties.Un videojuego, llamado Island, diseñado y desarrollado por un equipo multidisciplinar de clínicos, ingenieros y programadores, del que forma parte el Hospital Universitario de Bellvitge y en el que colaboran las profesoras Rosario Granero y Eva Penelo de la UAB, parece permitir a pacientes con enfermedades mentales adquirir nuevas estrategias para afrontar las propias emociones negativas en situaciones estresantes de la vida cotidiana. Estos pacientes también sienten que utilizando este videojuego participan más activamente en su proceso de recuperación. Así, los videojuegos aparecen con un futuro prometedor como complemento a tratamientos tradicionales de estas enfermedades