Break-up of Rydberg superatoms via dipole-dipole interactions

We investigate resonant dipole-dipole interactions between two "superatoms" of different angular momentum, consisting of two Rydberg-blockaded atom clouds where each of them carries initially a coherently shared single excitation. We demonstrate that the dipole-dipole interaction breaks up the superatoms by removing the excitations from the clouds. The dynamics is akin to an ensemble average over systems where only one atom per cloud participates in entangled motion and excitation transfer. Our findings should thus facilitate the experimental realization of adiabatic exciton transport in Rydberg systems by replacing single sites with atom clouds.Comment: 10 pages, 5 figure

Kicking electrons

The concept of dominant interaction hamiltonians is introduced and applied to classical planar electron-atom scattering. Each trajectory is governed in different time intervals by two variants of a separable approximate hamiltonian. Switching between them results in exchange of energy between the two electrons. A second mechanism condenses the electron-electron interaction to instants in time and leads to an exchange of energy and angular momentum among the two electrons in form of kicks. We calculate the approximate and full classical deflection functions and show that the latter can be interpreted in terms of the switching sequences of the approximate one. Finally, we demonstrate that the quantum results agree better with the approximate classical dynamical results than with the full ones.Comment: version 2: references adde

Imaging foreign bodies in head and neck trauma: a pictorial review

Open injuries bear the risk of foreign body contamination. Commonly encountered materials include gravel debris, glass fragments, wooden splinters or metal particles. While foreign body incorporation is obvious in some injury patterns, other injuries may not display hints of being contaminated with foreign body materials. Foreign objects that have not been detected and removed bear the risk of leading to severe wound infections and chronic wound healing disorders. Besides these severe health issues, medicolegal consequences should be considered. While an accurate clinical examination is the first step for the detection of foreign body materials, choosing the appropriate radiological imaging is decisive for the detection or non-detection of the foreign material. Especially in cases of impaired wound healing over time, the existence of an undetected foreign object needs to be considered. Here, we would like to give a practical radiological guide for the assessment of foreign objects in head and neck injuries by a special selection of patients with different injury patterns and various foreign body materials with regard to the present literature

Non-adiabatic dynamics in Rydberg gases with random atom positions

Assemblies of highly excited Rydberg atoms in an ultracold gas can be set into motion by a combination of van-der-Waals and resonant dipole-dipole interactions. Thereby, the collective electronic Rydberg state might change due to non-adiabatic transitions, in particular if the configuration encounters a conical interaction. For the experimentally most accessible scenario, in which the Rydberg atoms are initially randomly excited in a three-dimensional bulk gas under blockade conditions, we numerically show that non-adiabatic transitions can be common when starting from the most energetic repulsive BO-surface. We outline how this state can be selectively excited using a microwave resonance, and demonstrate a regime where almost all collisional ionization of Rydberg atoms can be traced back to a prior non-adiabatic transition. Since Rydberg ionisation is relatively straightforward to detect, the excitation and measurement scheme considered here renders non-adiabatic effects in Rydberg motion easier to demonstrate experimentally than in scenarios considered previously.Comment: 7 pages, 6 figure

Evolving Statistical Methodologies for Safeguards

Statistical methodologies for safeguards were developed at an early stage of safeguards’ history and are rooted in the criteria-driven, facility-based approach which has long underpinned the International Atomic Energy Agency’s (IAEA) conclusions. While their principles and approaches remain generally valid in the framework of a State-level evaluation, their scope, previously restricted to material balance areas (MBA) within facilities, needs to be expanded to include the analysis of nuclear material flows, inventories and balances for a whole State, taking into account the increasing use of random inspection schemes in State-level approaches (SLA) and the implications for the statistical analysis of data collected according to these patterns. In addition to this undertaking, which poses a number of methodological challenges, new approaches are needed to address increasingly large and diversified data flows, to optimize the distribution of limited statistical analysis resources, to align them with the State-level technical objectives (TO) identified through the acquisition path analysis (APA) performed by the State evaluation groups (SEGs) and to develop probabilistic methods for the quantification of their targeted and achieved attainment. In addition, statistical evaluation results of State declared and verification data need to be consolidated and compared to information from other sources. Last but not least, considerable progress was made in the field of information technology (IT) and statistical methodologies since they were first applied to safeguards several decades ago. The current migration of the IAEA safeguards IT platform under the Modernization of Safeguards Information technology (MOSAIC) project has provided a unique opportunity to adapt and evolve methodologies and to integrate them into new software tools. This paper reviews the efforts undertaken in recent years by the Nuclear Fuel Cycle Information Analysis Section within the Safeguards Department Division of Information Management to review, upgrade, consolidate, and evolve safeguards statistical methodologies and describes the progress accomplished to date

Impact of the adjacent bone on pseudarthrosis in mandibular reconstruction with fibula free flaps

Abstract Background Mechanical and morphological factors have both been described to influence the rate of pseudarthrosis in mandibular reconstruction. By minimizing mechanical confounders, the present study aims to evaluate the impact of bone origin at the intersegmental gap on osseous union. Methods Patients were screened retrospectively for undergoing multi-segment fibula free flap reconstruction of the mandible including the anterior part of the mandible and osteosynthesis using patient-specific 3D-printed titanium reconstruction plates. Percentage changes in bone volume and width at the bone interface between the fibula/fibula and fibula/mandible at the anterior intersegmental gaps within the same patient were determined using cone-beam computed tomography (CBCT). Additionally, representative samples of the intersegmental zones were assessed histologically and using micro-computed tomography (µCT). Results The bone interface (p = 0.223) did not significantly impact the change in bone volume at the intersegmental gap. Radiotherapy (p < 0.001), time between CBCT scans (p = 0.006) and wound healing disorders (p = 0.005) were independent risk factors for osseous non-union. Preliminary analysis of the microstructure of the intersegmental bone did not indicate morphological differences between fibula–fibula and fibula–mandible intersegmental bones. Conclusions The bone interface at the intersegmental gap in mandibular reconstruction did not influence long-term bone healing significantly. Mechanical and clinical properties seem to be more relevant for surgical success

An integrative systematic revision and biogeography of Rhynchocalamus snakes (Reptilia, Colubridae) with a description of a new species from Israel

[Background] The colubrid snakes of the genus Rhynchocalamus are seldom studied and knowledge of their ecology and life history is scarce. Three species of Rhynchocalamus are currently recognized, R. satunini (from Turkey eastwards to Iran), R. arabicus (Yemen and Oman), and R. melanocephalus (from the Sinai Peninsula northwards to Turkey). All are slender, secretive, mainly nocturnal and rare fossorial snakes. This comprehensive study is the first to sample all known Rhynchocalamus species in order to review the intra-generic phylogenetic relationships and historical biogeography of the genus.[Methods] We revised the systematics of Rhynchocalamus using an integrative approach and evaluated its phylogeography. The phylogenetic position within the Colubridae and the phylogenetic relationships within the genus were inferred using 29 individuals belonging to the three known species, with additional sampling of two other closely-related genera, Muhtarophis and Lytorhynchus. We analysed three mitochondrial (12S, 16S, cytb) and one nuclear (c-mos) gene fragments. Phylogenetic trees were reconstructed using maximum likelihood and Bayesian inference methods; the latter method also used to provide the first time-calibrated molecular phylogeny of the genus. We generated a nuclear network and carried out a topology test and species delimitation analysis. Morphological comparisons were used to differentiate among species and to describe a new species from Israel. The studied material was comprised of 108 alcohol-preserved specimens, 15 photographs, and data from the literature for the examination of 17 mensural, 14 meristic, and two categorical characters.[Results] The molecular results support Rhynchocalamus as monophyletic, and as having split from its sister genus Lytorhynchus during the Late Oligocene. The three recognized species of Rhynchocalamus comprise four independently evolving groups. The molecular results reveal that the genus began to diverge during the Middle Miocene. We revealed that the best-studied species, R. melanocephalus, is paraphyletic. A population, formally ascribed to this species, from the Negev Mountain area in southern Israel is phylogenetically closer to R. arabicus from Oman than to the northern populations of the species from Israel, Syria and Turkey. Herein we describe this population as a new species: Rhynchocalamus dayanae sp. nov.[Discussion] We identify four species within Rhynchocalamus: R. satunini, R. arabicus, R. melanocephalus, and R. dayanae sp. nov., the latter, to the best of our knowledge, is endemic to southern Israel. The onset of Rhynchocalamus diversification is very old and estimated to have occurred during the Middle Miocene, possibly originating in the Levant region. Radiation probably resulted from vicariance and dispersal events caused by continuous geological instability, sea-level fluctuations and climatic changes within the Levant region.This work was funded by grant CGL2015-70390-P from the Ministerio de Economía y Competitividad, Spain (co-funded by FEDER - EU). Karin Tamar is supported by the Steinhardt Museum of Natural History, Israel National Center for Biodiversity Studies, Tel-Aviv University, 6997801 Tel-Aviv, Israel.Peer reviewe

Statistical error model-based and GUM-based analysis of measurement uncertainties in nuclear safeguards – a reconciliation

At the occasion of the Consultants Group Meeting held to review the “International Target Values 2010 for Measurement Uncertainties in Safeguarding Nuclear Material”, discussions between experts highlighted theneed to improve communication between different safeguards measurement communities, e.g. laboratory analysts, non-destructive assay specialists, safeguards data evaluators, and to reconcile their approaches to estimating measurement uncertainties. The purpose of this paper is to contr ibute to reaching a common understanding of the terminology and methodologies used by different professional groups in the field of uncertainty quantification

Alpine-Himalayan orogeny drove correlated morphological, molecular, and ecological diversification in the Persian dwarf snake (Squamata: Serpentes: Eirenis persicus)

The Persian dwarf snake Eirenis (Pseudocyclophis) persicus (Anderson, 1872) has a wide distribution range in south-western Asia. This species group was comprehensively studied here using traditional biometry, geometric morphometrics, ecological niche modelling, and genetics. Our analyses revealed that E.persicus is split into two clades. A western clade, bearing at least two different species: E.persicus, distributed in south-western Iran, and an undescribed species from south-eastern Turkey and western Iran. The eastern clade consists of at least three species: Eirenis nigrofasciatus, distributed across north-eastern Iraq, and western and southern Iran; Eirenis walteri, distributed across eastern Iran, southern Turkmenistan, and western and southern Pakistan, and Eirenis angusticeps, distributed in north-eastern Pakistan. Ecological niche modelling revealed that the distribution of the species in the western clade are mainly affected by winter precipitation, and those in the eastern clade are mainly affected by the minimum temperature of the coldest month. A molecular clock analysis revealed that the divergence and diversification of the E.persicus species group mainly correspond to Eocene to Pliocene orogeny events subsequent to the Arabia-Eurasia collision. This study confirms that specimens with the unique morphology of having 13 dorsal scale rows on the anterior dorsum, occurring in the Suleiman Mountains in central Pakistan, can be referred to Eirenis mcmahoni (Wall, 1911). However, at this moment we have insufficient data to evaluate the taxonomy of this species