The Perilous Hunt: Symbols in Hispanic and European Balladry

In the symbolic language of ballads, a lady’s costly dress tells of the beauty of the body beneath it or of the wearer’s happiness; a lost hawk or hound foreshadows the hunter’s fate long before the plot reaches a turning point. In her original and far-reaching study of such familiar narrative elements, Edith Randam Rogers adds much to our understanding of poetic expression in the ballad tradition. In focusing on individual motifs as they appear in different ballads, different languages, and different periods, Rogers proves the existence of a reliable lingua franca of symbolism in European balladry. Lines or even whole stanzas that have defied interpretation often come to life when the reader is aware of the meaning of a particular motif in such an international vocabulary of images. Thus this book makes available important new critical tools sure to have significant results for ballad scholarship. Edith Randam Rogers is professor of Spanish at the University of Colorado at Denver. A considerable achievement in the use of the comparative method in the study of traditional folk balladry”—Choice.https://uknowledge.uky.edu/upk_spanish_literature/1017/thumbnail.jp

Improving Reversible Capacities of High-Surface Lithium Insertion Materials – The Case of Amorphous TiO2

Chemisorbed water and solvent molecules and their reactivity with components from the electrolyte in high-surface nanostructured electrodes remains a contributing factor towards capacity diminishment on cycling in lithium ion batteries due to the limit in maximum annealing temperature. Here we report a marked improvement in the capacity retention of amorphous TiO2 by the choice of preparation solvent, control of annealing temperature and the presence of surface functional groups. Careful heating of the amorphous TiO2 sample prepared in acetone under vacuum lead to complete removal of all molecular solvent and an improved capacity retention of 220 mAh/g over 50 cycles at a C/10 rate. Amorphous TiO2 when prepared in ethanol and heated under vacuum showed an even better capacity retention of 240 mAh/g. From FTIR Spectroscopy and Electron Energy Loss Spectroscopy measurements, the improved capacity is attributed to the complete removal of ethanol and the presence of very small fractions of residual functional groups coordinated to oxygen-deficient surface titanium sites. These displace the more reactive chemisorbed hydroxyl groups, limiting reaction with components from the electrolyte and possibly enhancing the integrity of the solid electrolyte interface (SEI). The present research provides a facile strategy to improve the capacity retention of nanostructured electrode materials

Advances in design of high-performance heterostructured scintillators for time-of-flight positron emission tomography

Core to advancing time-of-flight positron emission tomography (ToF-PET) toward a less invasive, more flexible procedure with a higher diagnostic power is the development of enhanced radiation detector materials. One promising avenue is the development of heterostructured scintillators where multiple materials work in synergy to exceed the performance of each individual component. Applied to ToF-PET detectors, one component contributes predominantly to the absorption of gamma rays and the other to the creation of ultra-fast photons. Whilst other authors have proposed various concepts, heterostructured scintillators are still in their infancy and scientifically guiding their development remains a challenge. Toward this aim and based on simulation and modeling developments, heterostructure properties are directly linked to ToF-PET performance. This is made possible by redefining the notions of detector photo-peak efficiency and timing response, as defined for monolithic detectors, in the context of heterostructured scintillators. Their overall potential is then discussed as a function of the materials and design used. This provides a quantitative framework to rapidly and efficiently support the advancement of heterostructured detectors for ToF-PET technology.Engineering and Physical Sciences Research Council (EPSRC): EP/S013652/

Fast emitting nanocomposites for high-resolution ToF-PET imaging based on multicomponent scintillators

Time-of-Flight Positron Emission Tomography is a medical imaging technique, based on the detection of two back-to-back {\gamma}-photons generated from radiotracers injected in the body. Its limit is the ability of employed scintillation detectors to discriminate in time the arrival of {\gamma}-pairs, i.e. the coincidence time resolution (CTR). A CTR < 50 ps that would enable fast imaging with ultralow radiotracer dose. Monolithic materials do not have simultaneously the required high light output and fast emission characteristics, thus the concept of scintillating heterostructure is proposed, where the device is made of a dense scintillator coupled to a fast-emitting light material. Here we present a composite polymeric scintillator, whose density has been increased upon addition of hafnium oxide nanoparticles. This enhanced by +300% its scintillation yield, surpassing commercial plastic scintillators. The nanocomposite is coupled to bismuth germanate oxide (BGO) realizing a multilayer scintillator. We observed the energy sharing between its components, which activate the nanocomposite fast emission enabling a net CTR improvement of 25% with respect to monolithic BGO. These results demonstrate that a controlled loading with dense nanomaterials is an excellent strategy to enhance the performance of polymeric scintillators for their use in advanced radiation detection and imaging technologies

A mathematical examination of the impact of mould transparency to infrared radiation on solidification during the investment casting process

Investment casting is a highly dynamic process during which multiple competing physical phenomena are at work. Those seeking to understand and simulate such processes computationally are confronted with a considerable task, balancing accuracy with efficiency. Approximations and models based on well-understood and documented fundamental physics are powerful tools in a modeller's arsenal. Driven by observed discrepancies between experimental thermocouple measurements and simulation predictions of casting temperatures, this work explores the additional alloy cooling mechanism of mould transparency to infrared radiation, targeting a new mathematical approximation applicable in such situations. Direct attenuation, scattering from coarse sand, sand distribution in the mould and material temperatures play a role in the extent of radiation transparency that must be considered. From this model, estimation of the additional cooling rate resulting from expected mould transparency can be determined and applied as a corrective measure to computation fluid dynamics (CFD) simulation results that do not capture this phenomenon

Two-dimensional perovskite functionalized fiber-type heterostructured scintillators

A fiber-type heterostructured scintillator based on bismuth germanate (Bi4Ge3O12) functionalized with the 2D-perovskite butylammonium lead bromide ((BA)2PbBr4) has been fabricated, and its scintillation performance analyzed toward its use for fast timing applications such as time-of-flight Positron Emission Tomography. The pixel shows energy sharing between the matrix and filler component, confirming that the two components are in synergy

The Genomic and Immune Landscapes of Lethal Metastatic Breast Cancer

TCR repertoire; Breast cancer; Clade mutationsRepertori TCR; Càncer de mama; Mutacions cladeRepertorio TCR; Cáncer de mama; Mutaciones cladoThe detailed molecular characterization of lethal cancers is a prerequisite to understanding resistance to therapy and escape from cancer immunoediting. We performed extensive multi-platform profiling of multi-regional metastases in autopsies from 10 patients with therapy-resistant breast cancer. The integrated genomic and immune landscapes show that metastases propagate and evolve as communities of clones, reveal their predicted neo-antigen landscapes, and show that they can accumulate HLA loss of heterozygosity (LOH). The data further identify variable tumor microenvironments and reveal, through analyses of T cell receptor repertoires, that adaptive immune responses appear to co-evolve with the metastatic genomes. These findings reveal in fine detail the landscapes of lethal metastatic breast cancer

Reliability of Quantitative Real-Time PCR for Bacterial Detection in Cystic Fibrosis Airway Specimens

The cystic fibrosis (CF) airway microbiome is complex; polymicrobial infections are common, and the presence of fastidious bacteria including anaerobes make culture-based diagnosis challenging. Quantitative real-time PCR (qPCR) offers a culture-independent method for bacterial quantification that may improve diagnosis of CF airway infections; however, the reliability of qPCR applied to CF airway specimens is unknown. We sought to determine the reliability of nine specific bacterial qPCR assays (total bacteria, three typical CF pathogens, and five anaerobes) applied to CF airway specimens. Airway and salivary specimens from clinically stable pediatric CF subjects were collected. Quantitative PCR assay repeatability was determined using triplicate reactions. Split-sample measurements were performed to measure variability introduced by DNA extraction. Results from qPCR were compared to standard microbial culture for Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae, common pathogens in CF. We obtained 84 sputa, 47 oropharyngeal and 27 salivary specimens from 16 pediatric subjects with CF. Quantitative PCR detected bacterial DNA in over 97% of specimens. All qPCR assays were highly reproducible at quantities ≥102 rRNA gene copies/reaction with coefficient of variation less than 20% for over 99% of samples. There was also excellent agreement between samples processed in duplicate. Anaerobic bacteria were highly prevalent and were detected in mean quantities similar to that of typical CF pathogens. Compared to a composite gold standard, qPCR and culture had variable sensitivities for detection of P. aeruginosa, S. aureus and H. influenzae from CF airway samples. By reliably quantifying fastidious airway bacteria, qPCR may improve our understanding of polymicrobial CF lung infections, progression of lung disease and ultimately improve antimicrobial treatments