Micrometer-sized ice particles for planetary-science experiments – II. Bidirectional reflectance

We have measured the bidirectional reflectance of spherical micrometer-sized water-ice particles in the visible spectral range over a wide range of incidence and emission angles. The small ice spheres were produced by spraying fine water droplets directly into liquid nitrogen. The resulting mean particle radii are 1.47 + 0.96 - 0.58 μm. Such a material shares many properties with ice in comets and at the surface of icy satellites. Measurements show that the fresh sample material is highly backscattering, contrasting with natural terrestrial snow and frost. The formation of agglomerates of particles during the sample production results in a noticeable variability of the photometric properties of the samples in their initial state. We have also observed significant temporal evolutions of the scattering behavior of the samples, shifting towards more forward scattering within some tens of hours, resulting most likely from sintering processes. All reflectance data are fitted by the Hapke photometric model (1993 and 2002 formulation) with a one/two/three-parameter Henyey-Greenstein phase function and the resulting Hapke parameters are provided. These parameters can be used to compare laboratory results with the observed photometric behaviors of astronomical objects. We show, in particular, that the optical properties of the fresh micrometer-sized ice samples can be used to reproduce the predominant backscattering in the phase curves of Enceladus and Europa.

Plan of a dictionary of Anglo-Jewish biography : [English, American, and colonial]

by Lucien Wolf

A Hebrew and English and English and Hebrew Dictionary with roots and abbreviations

by Abigail Lindo

A complete english dictionary of the roots of the world-language Volapük, invented by Mgr. Schleyer Johann Martin

comp. and transl. by Scherzinger J. Arnold

A dictionary of the Targumim, the Talmud Babli and Yerushalmi, and the Midrashic literature : with an index of scriptural quotations

compiled by Marcus Jastrow

Length of the Mitral Isthmus But Not Anatomical Location of Ablation Line Predicts Bidirectional Mitral Isthmus Block in Patients Undergoing Catheter Ablation of Persistent Atrial Fibrillation: A Randomized Controlled Trial

INTRODUCTION Mitral isthmus (MI) ablation is an effective option in patients undergoing ablation for persistent atrial fibrillation (AF). Achieving bidirectional conduction block across the MI is challenging, and predictors of MI ablation success remain incompletely understood. We sought to determine the impact of anatomical location of the ablation line on the efficacy of MI ablation. METHODS AND RESULTS A total of 40 consecutive patients (87% male; 54 ± 10 years) undergoing stepwise AF ablation were included. MI ablation was performed in sinus rhythm. MI ablation was performed from the left inferior PV to either the posterior (group 1) or the anterolateral (group 2) mitral annulus depending on randomization. The length of the MI line (measured with the 3D mapping system) and the amplitude of the EGMs at 3 positions on the MI were measured in each patient. MI block was achieved in 14/19 (74%) patients in group 1 and 15/21 (71%) patients in group 2 (P = NS). Total MI radiofrequency time (18 ± 7 min vs. 17 ± 8 min; P = NS) was similar between groups. Patients with incomplete MI block had a longer MI length (34 ± 6 mm vs. 24 ± 5 mm; P < 0.001), a higher bipolar voltage along the MI (1.75 ± 0.74 mV vs. 1.05 ± 0.69 mV; P < 0.01), and a longer history of continuous AF (19 ± 17 months vs. 10 ± 10 months; P < 0.05). In multivariate analysis, decreased length of the MI was an independent predictor of successful MI block (OR 1.5; 95% CI 1.1-2.1; P < 0.05). CONCLUSIONS Increased length but not anatomical location of the MI predicts failure to achieve bidirectional MI block during ablation of persistent AF.

Endovascular stent reconstruction of a chronic total occlusion of the inferior vena cava using bidirectional wire access and a balloon puncture by a re-entry device.

Venous angioplasty with stenting of iliac veins is an important treatment option for patients suffering from post-thrombotic syndrome due to chronic venous obstruction. Interventional treatment of a chronically occluded vena cava, however, is challenging and often associated with failure. We describe a case of a chronic total occlusion of the entire inferior vena cava that was successfully recanalized using bidirectional wire access and a balloon puncture by a re-entry catheter to establish patency of the inferior vena cava.

Neuroimmune Interactions: a Bidirectional Flow that Leads to Health and Disease

The Vedic philosophy deals with harmony and balance between the mind and the body as well as interactions with nature. This ancient approach to health and well-being is being more and more appreciated in part as we understand the intimate relationship between the immune system, our major defense mechanism and the nervous system. Like other organ systems, the immune system is dependent on the central nervous system (CNS) and the endocrine system in its role for effective defense against foreign and domestic invaders.

A Nika-English dictionary

by L. Krapf and J. Rebmann