Collision strengths and transition probabilities for Co II infrared forbidden lines

We calculate collision strengths and their thermally-averaged Maxwellian values for electron excitation and de-excitation between the fifteen lowest levels of singly-ionised cobalt, Co+, which give rise to emission lines in the near- and mid-infrared. Transition probabilities are also calculated and relative line intensities predicted for conditions typical of supernova ejecta. The diagnostic potential of the 10.52, 15.46 and 14.74 micro-metre transition lines is briefly discussed.Comment: 9 pages, 4 figures, 7 table

Stream Fusion, to Completeness

Stream processing is mainstream (again): Widely-used stream libraries are now available for virtually all modern OO and functional languages, from Java to C# to Scala to OCaml to Haskell. Yet expressivity and performance are still lacking. For instance, the popular, well-optimized Java 8 streams do not support the zip operator and are still an order of magnitude slower than hand-written loops. We present the first approach that represents the full generality of stream processing and eliminates overheads, via the use of staging. It is based on an unusually rich semantic model of stream interaction. We support any combination of zipping, nesting (or flat-mapping), sub-ranging, filtering, mapping-of finite or infinite streams. Our model captures idiosyncrasies that a programmer uses in optimizing stream pipelines, such as rate differences and the choice of a "for" vs. "while" loops. Our approach delivers hand-written-like code, but automatically. It explicitly avoids the reliance on black-box optimizers and sufficiently-smart compilers, offering highest, guaranteed and portable performance. Our approach relies on high-level concepts that are then readily mapped into an implementation. Accordingly, we have two distinct implementations: an OCaml stream library, staged via MetaOCaml, and a Scala library for the JVM, staged via LMS. In both cases, we derive libraries richer and simultaneously many tens of times faster than past work. We greatly exceed in performance the standard stream libraries available in Java, Scala and OCaml, including the well-optimized Java 8 streams

Reconnection and acoustic emission of quantized vortices in superfluid by the numerical analysis of the Gross-Pitaevskii equation

We study numerically the reconnection of quantized vortices and the concurrent acoustic emission by the analysis of the Gross-Pitaevskii equation. Two quantized vortices reconnect following the process similar to classical vortices; they approach, twist themselves locally so that they become anti-parallel at the closest place, reconnect and leave separately.The investigation of the motion of the singular lines where the amplitude of the wave function vanishes in the vortex cores confirms that they follow the above scenario by reconnecting at a point. This reconnection is not contradictory to the Kelvin's circulation theorem, because the potential of the superflow field becomes undefined at the reconnection point. When the locally anti-parallel part of the vortices becomes closer than the healing length, it moves with the velocity comparable to the sound velocity, emits the sound waves and leads to the pair annihilation or reconnection; this phenomena is concerned with the Cherenkov resonance. The vortices are broken up to smaller vortex loops through a series of reconnection, eventually disappearing with the acoustic emission. This may correspond to the final stage of the vortex cascade process proposed by Feynman. The change in energy components, such as the quantum, the compressible and incompressible kinetic energy is analyzed for each dynamics. The propagation of the sound waves not only appears in the profile of the amplitude of the wave function but also affects the field of its phase, transforming the quantum energy due to the vortex cores to the kinetic energy of the phase field.Comment: 11 pages, 16 figures, LaTe

Molecular characterization of resistance to rifampicin in clinical isolates of Neisseria meningitidis

AbstractAmong 3904 meningococcal isolates collected between October 2002 and June 2007 by the French Meningococcal Reference Centre, eight (0.20%) were resistant to rifampicin (Rif-R; MIC >1 mg/L) and 27 (0.69%) were intermediate-resistant to rifampicin (Rif-I; MICs between 0.38 mg/L and 1 mg/L) according to the E-test method. The MICs determined by agar dilution were lower, eliminating the E-test intermediate category. All Rif-R isolates had mutations in the rpoB gene, resulting in substitutions at or near amino acid position 552, which were absent in non-resistant isolates. These data suggest that a rifampicin clinical breakpoint of 1.0 mg/L should be adopted for Neisseria meningitidis

Utilising semantic technologies for intelligent indexing and retrieval of digital images

The proliferation of digital media has led to a huge interest in classifying and indexing media objects for generic search and usage. In particular, we are witnessing colossal growth in digital image repositories that are difficult to navigate using free-text search mechanisms, which often return inaccurate matches as they in principle rely on statistical analysis of query keyword recurrence in the image annotation or surrounding text. In this paper we present a semantically-enabled image annotation and retrieval engine that is designed to satisfy the requirements of the commercial image collections market in terms of both accuracy and efficiency of the retrieval process. Our search engine relies on methodically structured ontologies for image annotation, thus allowing for more intelligent reasoning about the image content and subsequently obtaining a more accurate set of results and a richer set of alternatives matchmaking the original query. We also show how our well-analysed and designed domain ontology contributes to the implicit expansion of user queries as well as the exploitation of lexical databases for explicit semantic-based query expansion

A case of portal hypertension due to a superior mesenteric arteriovenous fistula

Introduction: Superior mesenteric arteriovenous fistula (SMAVF) is an infrequent vascular disorder characterized by abnormal communication between high-pressure superior mesenteric artery and low-pressure superior mesenteric vein. This allows blood to bypass the intestinal capillary bed and produces portal hypertension leading to ascites and gastro-esophageal variceal bleeding. Although SMAVF can be congenital, most reported cases have been due to abdominal trauma or iatrogenic causes. Here, we report a case of SMAVF presenting as severe ascites. Case presentation: A 61-year-old female presented to the emergency department with a 1-week history of abdominal distention and discomfort. Her past medical history was significant for abdominal hysterectomy complicated by bowel resection. Initial evaluation was remarkable for severe hyponatremia and severe abdominal and pelvic ascites evidenced on computed tomography. A paracentesis was performed, fluid analysis was negative for spontaneous bacterial peritonitis. The Serum Ascites Albumin Gradient was elevated (\u3e1.1 g/dL). The hospital course was complicated by gastrointestinal bleeding requiring blood transfusions. An upper endoscopy revealed bleeding esophageal varices that were banded. A magnetic resonance of the abdomen revealed a large SMAVF between causing increased portal vein blood flow and pressure; the patient subsequently underwent embolization of the SMAVF. The patient clinically improved and was discharged on stable condition. On follow-up after discharge, cross sectional imaging revealed improved appearance of the mesenteric vasculature and resolution of the ascites. Discussion: This case illustrates the for clinicians to be vigilant for rare but reversible causes of portal hypertension that can mimic cirrhosis in order to provide appropriate diagnosis and management.https://scholarlycommons.henryford.com/merf2020caserpt/1028/thumbnail.jp

State-to-state rovibrational transition rates for CO2 in the bend mode in collisions with He atoms

Modeling environments that are not in local thermal equilibrium, such as protoplanetary disks or planetary atmospheres, with molecular spectroscopic data from space telescopes requires knowledge of the rate coefficients of rovibrationally inelastic molecular collisions. Here, we present such rate coefficients in a temperature range from 10 to 500 K for collisions of CO$_2$ with He atoms in which CO$_2$ is (de)excited in the bend mode. They are obtained from numerically exact coupled-channel (CC) calculations as well as from calculations with the less demanding coupled-states approximation (CSA) and the vibrational close-coupling rotational infinite-order sudden (VCC-IOS) method. All of the calculations are based on a newly calculated accurate ab initio four-dimensional CO$_2$-He potential surface including the CO$_2$ bend ($\nu_2$) mode. We find that the rovibrationally inelastic collision cross sections and rate coefficients from the CSA and VCC-IOS calculations agree to within 50% with the CC results at the rotational state-to-state level, except for the smaller ones and in the low energy resonance region, and to within 20% for the overall vibrational quenching rates except for temperatures below 50 K where resonances provide a substantial contribution. Our CC quenching rates agree with the most recent experimental data within the error bars. We also compared our results with data from Clary et al. calculated in the 1980's with the CSA and VCC-IOS methods and a simple atom-atom model potential based on ab initio Hartree-Fock calculations and found that their cross sections agree fairly well with ours for collision energies above 500 cm$^{-1}$, but that the inclusion of long range attractive dispersion interactions is crucial to obtain reliable cross sections at lower energies and rate coefficients at lower temperatures.Comment: The article has been accepted to the Journal of Chemical Physic

Greenfield HSA Service Learning Project

Albert M. Greenfield Elementary School is a kindergarten to eighth-grade public school in Philadelphia, Pennsylvania. The Greenfield Home and School Association (HSA) is a parent organization whose efforts to support the school include sending weekly informational newsletters and by fundraising for school improvements. The HSA recently has become concerned that Greenfield teachers may be struggling with burnout originating from increasing demands placed upon them by pandemic-related stresses. The HSA asked for help in identifying and evaluating positive psychology interventions that could be used at Greenfield to reduce teacher burnout and increase teacher well-being. Three students from the Master of Positive Psychology (MAPP) program at the University of Pennsylvania addressed the concerns of the HSA by developing well-being interventions that might be adopted by the HSA as part of their programming over the next year. The interventions proposed by the MAPP students included administering a teacher burnout and well-being survey, adopting a mission statement that incorporated a well-being purpose for the organization, developing micro-interventions that could be easily and quickly used by teachers, improving the teachers’ lounge for greater well-being, and hosting a positive psychology retreat for teachers. Each of these interventions, described in detail in this report, was intended to use the principles of positive psychology to alleviate and prevent burnout in teachers and help build and enhance the resilience of the school community post-pandemic