Geometries of the antiproton-nucleus optical potentials at 180 MeV

The moments of the real and the absorptive parts of the antiproton optical potentials are evaluated for the first time to study the geometries of the potentials at 180 MeV. Interesting features are revealed which are found to be comparable to the proton case in general despite the presence of strong annihilation. A few interesting deviations, however, are also found compared to the proton case.

Influence of rock depth on seismic site classification for shallow bedrock regions

Seismic site classifications are used to represent site effects for estimating hazard parameters (response spectral ordinates) at the soil surface. Seismic site classifications have generally been carried out using average shear wave velocity and/or standard penetration test n-values of top 30-m soil layers, according to the recommendations of the National Earthquake Hazards Reduction Program (NEHRP) or the International Building Code (IBC). The site classification system in the NEHRP and the IBC is based on the studies carried out in the United States where soil layers extend up to several hundred meters before reaching any distinct soil-bedrock interface and may not be directly applicable to other regions, especially in regions having shallow geological deposits. This paper investigates the influence of rock depth on site classes based on the recommendations of the NEHRP and the IBC. For this study, soil sites having a wide range of average shear wave velocities (or standard penetration test n-values) have been collected from different parts of Australia, China, and India. Shear wave velocities of rock layers underneath soil layers have also been collected at depths from a few meters to 180 m. It is shown that a site classification system based on the top 30-m soil layers often represents stiffer site classes for soil sites having shallow rock depths (rock depths less than 25 m from the soil surface). A new site classification system based on average soil thickness up to engineering bedrock has been proposed herein, which is considered more representative for soil sites in shallow bedrock regions. It has been observed that response spectral ordinates, amplification factors, and site periods estimated using one-dimensional shear wave analysis considering the depth of engineering bedrock are different from those obtained considering top 30-m soil layers.

A taxonomic mystery for more than 180 years: the identity and systematic position of Brachysaura minor (HARDWICKE & GRAY, 1827)

Brachysaura is a monotypic genus of agamid lizard found in the Indian subcontinent; the identity and systematic position of B. minor has been long debated, and it has at times been subsumed into Agama, Charasia and Laudakia, with some authors suggesting affinities to Calotes. We constructed nuclear and mitochondrial phylogenetic trees including Brachysaura and allied agamid genera to resolve its phylogenetic position. We also compared osteology and external morphology with the genera Agama, Calotes and Laudakia. Hemipenial morphology was compared with Calotes and some other agamids from South Asia. Both nuclear and mitochondrial phylogenies demonstrate that Brachysaura is nested within the widespread South and Southeast Asian genus Calotes, with which it also shares certain external morphological, osteological and hemipenial characters. Adaptations to ground dwelling in Brachysaura minor has resulted in unique modifications to its body plan, which is likely why generic allocation has been long confused. This study also highlights the need for an integrated systematic approach to resolve taxonomic ambiguity in Asian agamids.