Displaced Drude peak and bad metal from the interaction with slow fluctuations.

Scattering by slowly fluctuating degrees of freedom can cause a transient localization of the current-carrying electrons in metals, driving the system away from normal metallic behavior. We illustrate and characterize this general phenomenon by studying how signatures of localization emerge in the optical conductivity of electrons interacting with slow bosonic fluctuations. The buildup of quantum localization corrections manifests itself in the emergence of a displaced Drude peak (DDP), whose existence strongly alters the low frequency optical response and suppresses the d.c. conductivity. We find that for sufficiently strong interactions, many-body renormalization of the fluctuating field induced at metallic densities enhances electron localization and the ensuing DDP phenomenon in comparison with the well-studied low concentration limit. Our results are compatible with the frequent observation of DDPs in electronic systems where slowly fluctuating degrees of freedom couple significantly to the charge carriers.

Mechanisms for log normal concentration distributions in the environment

Log normal-like concentration distributions are ubiquitously observed in the environment. However, the mechanistic origins are not well understood. In this paper, we show that first order exponential kinetics onsets log-normal concentration distributions, under certain assumptions. Given the ubiquity of exponential kinetics, e.g., source and sink processes, this model suggests an explanation for the frequent observation in the environment, and elsewhere. We compare this model to other mechanisms affecting concentration distributions, e.g., source mixing. Finally, we discuss possible implications for data analysis and modelling, e.g., log-normal rates and fluxes.

The effect of developmental pleiotropy on the evolution of immune genes in Drosophila melanogaster

The pressure to survive relentless pathogen exposure explains the frequent observation that immune genes are among the fastest-evolving ones in the genomes of many taxa, but an intriguing proportion of immune genes also appear to be under purifying selection. Though variance in evolutionary signatures of immune genes is often attributed to differences in gene-specific interactions with microbes, this explanation neglects the possibility that immune genes pleiotropically participate in other biological processes that could constrain adaptive selection. In this study, we analyzed available transcriptomic and manual annotation data from Drosophila melanogaster to uncover substantial pleiotropic overlap in the developmental and immunological functions of genes involved in immune signaling. As developmental pleiotropy could constrain both the deployment and evolution of a gene product for immunological purposes, we predicted that pleiotropic immune genes would show stronger signatures of purifying selection than non-pleiotropic immune genes. We further predicted that, within the pleiotropic gene class, genes expressed early in development or more broadly across developmental stages would be under stronger purifying selection than genes with stage-specific functions. Using population genomics data from D. melanogaster and related species, we show that pleiotropic immune genes do undergo slightly slower evolutionary rates than those having no known developmental functions, and that signatures of purifying selection are significantly stronger for broadly-expressed pleiotropic immune genes. This study underscores the need to investigate immune system evolution in the broader context of host life history and development, and raises new questions about the evolution and maintenance of pleiotropic genetic architecture.

Beyond Last Words: Patterns of Linguistic and Interactional Behavior in a Historical Sample of Dying Hospital Patients

Patterns of linguistic and interactional behavior by people at the very end of their lives are not well described, partly because data is difficult to obtain. This paper analyzes descriptions of 486 deaths gathered from 1900 to 1904 in the first-ever clinical study of dying by noted Canadian physician, Sir William Osler. Only 16 patients were noted speaking, and only four canonical last words were reported. The most frequent observation by medical staff was that the deaths were quiet ( n = 30), though range of other behaviors were noted (e.g., moaning, delirium, seeming intention to speak). Osler's problematic study left behind data whose analysis is a small step toward empirically characterizing the linguistic and interactional details of a previously under-described phenomena as well as the importance of the social context in which they occur.

The synaptonemal complex imposes crossover interference and heterochiasmy in Arabidopsis

Meiotic crossovers (COs) have intriguing patterning properties, including CO interference, the tendency of COs to be well-spaced along chromosomes, and heterochiasmy, the marked difference in male and female CO rates. During meiosis, transverse filaments transiently associate the axes of homologous chromosomes, a process called synapsis that is essential for CO formation in many eukaryotes. Here, we describe the spatial organization of the transverse filaments in Arabidopsis (ZYP1) and show it to be evolutionary conserved. We show that in the absence of ZYP1 (zyp1a zyp1b null mutants), chromosomes associate in pairs but do not synapse. Unexpectedly, in absence of ZYP1, CO formation is not prevented but increased. Furthermore, genome-wide analysis of recombination revealed that CO interference is abolished, with the frequent observation of close COs. In addition, heterochiasmy was erased, with identical CO rates in males and females. This shows that the tripartite synaptonemal complex is dispensable for CO formation and has a key role in regulating their number and distribution, imposing CO interference and heterochiasmy.

Is dealing with errors in the classroom specific for school subjects? A study of the error climate in mathematics, German, and English

A frequent observation in the school context is that opportunities to learn from errors are often missed. However, a positive error climate may support learning from errors. For the school subject of mathematics, some findings about characteristics of the error climate already exist. But, a comparison of the error climate between different school subjects is still pending. In the present study, it is analyzed whether the error climate differs in different school subjects and whether the same interrelations between the ways in which individuals deal with errors can be found in these different school subjects. In a study with 937 students from 48 classrooms from grades 5 to 7, in different secondary schools in Germany and Austria, we assessed the error climate and individual reactions following errors in mathematics, German, and English. Small mean differences between mathematics and the two language subjects were yielded. In addition, we found medium-sized correlations between the error climate measures in the three school subjects. However, the same pattern of interrelations between error climate and the way individuals deal with errors for all three school subjects could be shown. The results suggest that the perception of the error climate is rather similar in different school subjects. This has implications, for instance, for interventions that aim at fostering the error climate.

Conductive hearing loss after surgical treatment of otosclerosis—long-term observations

Introduction: Surgical treatment of otosclerosis has been a commonly accepted method of treatment for many years. The improvement of hearing after surgery is sometimes even spectacular, and good results are obtained in many centres in over 90% of the entire operated population. However, in the years following the procedure, some patients develop permanent or progressive conductive hearing loss. The aim of the study is to present a group of patients with conductive hearing loss that appeared after the first otosclerosis surgery and to analyse the causes of its occurrence. Material and Methods: Retrospective analysis was performed on patients who were first operated on in the years 2000-2009. Their medical records were analysed by the end of 2019, which made it possible to obtain results on at least 10 years of postoperative follow-up. The group consisted of 1118 patients, aged 14-82, including 802 women and 316 men. Results: Reoperations due to conductive hearing loss were performed on 93 patients, who accounted for 8.3% of the originally operated patients. They were much more often performed on patients after stapedectomies (19.7%) than on patients after stapedotomy (5.5%). Intraoperatively, prosthesis displacement was found to be the most frequent observation (44.1%) and was often associated with erosion or necrosis of the long process of incus (28%). Less frequent reasons of hearing loss were: adhesions around the prosthesis (10.8%), too small hole in the stapes footplate (8.6%), too short prosthesis (8.6%), progression of otosclerosis (7.5%), too long prosthesis (6.4%), presence of a granuloma around the prosthesis (5.4 %), and displacement of incus (4.3%). Conclusions: Surgical treatment in otosclerosis is a widely accepted and good method. It allows improvement in hearing in the vast majority of patients treated in this way. Unfortunately, over the years, some patients develop conductive hearing loss again. Reoperation gives a chance to find the cause and improve hearing in most of these cases.

Bioorganometallic Technetium and Rhenium Chemistry: Fundamentals for Applications

Due to its long half-life of 2.111×105 y, technetium, i.e. 99Tc, offers the excellent opportunity of combining fundamental and ' classical ' organometallic or coordination chemistry with all methodologies of radiochemistry. Technetium chemistry is inspired by the applications of its short-lived metastable isomer 99mTc in molecular imaging and radiopharmacy. We present in this article examples about these contexts and the impact of purely basic oriented research on practical applications. This review shows how the chemistry of this element in the middle of the periodic system inspires the chemistry of neighboring elements such as rhenium. Reasons are given for the frequent observation that the chemistries of 99Tc and 99mTc are often not identical, i.e. compounds accessible for 99mTc, under certain conditions, are not accessible for 99Tc. The article emphasizes the importance of macroscopic technetium chemistry not only for research but also for advanced education in the general fields of radiochemistry.

The architecture of corneal stromal striae on optical coherence tomography and histology in an animal model and in humans

The purpose of this study was to use a portable optical coherence tomography (OCT) for characterization of corneal stromal striae (CSS) in an ovine animal model and human corneas with histological correlation, in order to evaluate their architectural pattern by image analysis. Forty-six eyes from female adult sheep (older than 2 years), and 12 human corneas, were included in our study. The eyes were examined in situ by a portable OCT, without enucleation. All OCT scans were performed immediately after death, and then the eyes were delivered to a qualified histology laboratory. In the ovine animal model, CSS were detected with OCT in 89.1% (41/46) of individual scans and in 93.4% (43/46) of histological slices. In human corneas, CSS were found in 58.3% (7/12) of cases. In both corneal types, CSS appeared as “V”- or “X”-shaped structures, with very similar angle values of 70.8° ± 4° on OCT images and 71° ± 4° on histological slices (p ≤ 0.01). Data analysis demonstrated an excellent degree of reproducibility and inter-rater reliability of measurements (p < 0.001). The present study demonstrated that by using a portable OCT device, CSS can be visualized in ovine and human corneas. This finding suggests their generalized presence in various mammals. The frequent observation, close to 60%, of such collagen texture in the corneal stroma, similar to a ‘truss bridge’ design, permits to presume that it plays an important structural role, aimed to distribute tensile and compressive forces in various directions, conferring resilience properties to the cornea.