Logarithmic Vertex Algebras

We introduce and study the notion of a logarithmic vertex algebra, which is a vertex algebra with logarithmic singularities in the operator product expansion of quantum fields; thus providing a rigorous formulation of the algebraic properties of quantum fields in logarithmic conformal field theory. We develop a framework that allows many results about vertex algebras to be extended to logarithmic vertex algebras, including in particular the Borcherds identity and Kac Existence Theorem. Several examples are investigated in detail, and they exhibit some unexpected new features that are peculiar to the logarithmic case.Comment: 62 page

Periwinkles and parasites: the occurrence and phenotypic effects of parasites in Littorina saxatilis and L. arcana in northeastern England

Littorina saxatilis is a common intertidal gastropod on shores of the North Atlantic, and an 24 important study species for evolutionary investigations. Its congener L. arcana is much less 25 widely distributed, but both species are common at Old Peak, Yorkshire, UK. The parasite 26 profiles of L. saxatilis and L. arcana from this shore were determined histologically, revealing 27 a ciliated protist, Protophrya ovicola, an unidentified apicomplexan (present in <1% L. 28 saxatilis) and three trematode parasites tentatively assigned to Renicola sp., Microphallus 29 similis and M. pygmaeus. The profile data include prevalence information and associated 30 histology. Protophrya ovicola associated predominantly with the wave ecotype of L. saxatilis 31 (65%) rather than the crab ecotype (16%). Microphallus similis occurred at a higher 32 prevalence in the L. arcana population (38%) in comparison with the L. saxatilis population 33 (11%). Overall, there appeared to be a lower prevalence of trematodes in the high-shore L. 34 saxatilis. By modelling occurrence of individual parasites and shell morphometrics, an 35 assessment of parasite-associated morphological change was conducted. We conclude that 36 parasitism appeared not to cause shell-shape change, but rather that snails of a certain shell 37 shape were more likely to display infection. Records of parasites in L. saxatilis and L. arcana 38 are briefly reviewed, showing that the diversity of parasites reported here is relatively low

Fluctuating asymmetry, parasitism and reproductive fitness in two species of gammarid crustacean

Fluctuating asymmetry (FA), defined as random deviations from perfect bilateral symmetry, is assumed to reflect developmental instability. FA is predicted to increase in response to environmental stress, including parasite infection. In addition, based on theory we predict a higher FA in sexually selected traits, due to their greater sensitivity to stress. We investigated the relationships between FA, parasitism and reproductive fitness in 2 species of gammarid crustacean, incorporating both sexual and non-sexual traits. We tested the hypothesis that gammarids infected by vertically transmitted Microsporidia will display higher levels of FA than those infected by horizontally transmitted trematodes, because vertically transmitted Microsporidia can be present at the earliest stages of host development. We found little evidence for a relationship between FA and fecundity in Gammarus spp.; however, egg diameter for infected female Gammarus duebeni was significantly smaller than uninfected female G. duebeni. FA was not correlated with brood size in females or with sperm number in males. In contrast to our prediction, we report a lower relative FA in response to sexual traits than non-sexual traits. However, FA in sexual traits was found to be higher in males than females, supporting the theory that sexual selection leads to increased FA. Additionally, we report a negative correlation between FA and both trematode (Podocotyle atomon) and PCR-positive microsporidian (Nosema granulosis and Dictyocoela duebenum) infections and interpret these results in the context of the parasites’ transmission strategies. FA in G. duebeni and G. zaddachi appears to associate with trematode and microsporidian presence, although reproductive fitness is less altered by infection

Cucumispora ornata n. sp. (Fungi: Microsporidia) infecting invasive 1 ‘demon shrimp’

Dikerogammarus haemobaphes, the ‘demon shrimp’, is an amphipod native to the Ponto-Caspian region. This species invaded the UK in 2012 and has become widely established. Dikerogammarus haemobaphes has the potential to introduce non-native pathogens into the UK, creating a potential threat to native fauna. This study describes a novel species of microsporidian parasite infecting 72.8% of invasive D. haemobaphes located in the River Trent, UK. The microsporidium infection was systemic throughout the host; mainly targeting the sarcolemma of muscle tissues. Electron microscopy revealed this parasite to be diplokaryotic and have 7-9 turns of the polar filament. The microsporidium is placed into the ‘Cucumispora’ genus based on host histopathology, fine detail parasite ultrastructure, a highly similar life-cycle and SSU rDNA sequence phylogeny. Using this data this novel microsporidian species is named Cucumispora ornata, where ‘ornata’ refers to the external beading present on the mature spore stage of this organism. Alongside a taxonomic discussion, the presence of a novel Cucumispora sp. in the United Kingdom is discussed and related to the potential control of invasive Dikerogammarus spp. in the UK and the health of native species which may come into contact with this parasite

Podocotyle atomon (Trematoda: Digenea) impacts reproductive behaviour, survival and physiology in Gammarus zaddachi (Amphipoda)

The Trematoda are a group of phylogenetically diverse metazoan parasites that exhibit complex life cycles that often pass through invertebrate and vertebrate hosts. Some trematodes influence their host’s behaviour to benefit transmission. Their parasitic influence may impact host population size by inhibiting an individual’s reproductive capacity. We assessed the impact of infection by Podocotyle atomon on the reproductive behaviour and fecundity of its amphipod intermediate host, Gammarus zaddachi, using laboratory and field studies. Parasite prevalence was high in the field, with males more likely to be infected (prevalence in males 64%, in females 39%). Males also suffered a higher parasite burden than females. Infected females were less active, but we found no evidence for a reduction in female reproductive success. Infected females also had comparable pairing success to uninfected females. In males, infection reduced survival and fecundity, with mortality being highest, and sperm numbers lowest, in heavily infected individuals. Trematode parasites are sometimes associated with altered host fecundity, but studies often lack the relevant experimental data to explore the evolution of the trait. We discuss this among information specific to the effect of P. atomon infection in G. zaddachi

The Secondary Electron Yield of Technical Materials and its Variation with Surface Treatments

Secondary electron emission of surfaces exposed to oscillating electromagnetic field is at the origin of the multipacting effect that could severely perturb the operation of particle accelerators. This contribution tries to illustrate by measurement results, the origin of the secondary electron emission as well as the main reasons for the discrepancies between technical materials and pure metals. The variation of the secondary electron yield with the incident electron energy will be discussed for various types of technical surfaces. The influence of a gas condensation on these surfaces will also be addressed in the context of the LHC accelerator. Various treatments aiming at a permanent reduction of the secondary electron yield will be presented. A special attention will be paid to the decrease of the secondary electron yield under electron or photon impact and to its possible beneficial consequences for the processing of devices prone to multipacting

Targeting the Hippo/YAP/TAZ signalling pathway: Novel opportunities for therapeutic interventions into skin cancers

\ua9 2022 The Authors. Experimental Dermatology published by John Wiley &amp; Sons Ltd.Skin cancers are by far the most frequently diagnosed human cancers. The closely related transcriptional co-regulator proteins YAP and TAZ (WWTR1) have emerged as important drivers of tumour initiation, progression and metastasis in melanoma and non-melanoma skin cancers. YAP/TAZ serve as an essential signalling hub by integrating signals from multiple upstream pathways. In this review, we summarize the roles of YAP/TAZ in skin physiology and tumorigenesis and discuss recent efforts of therapeutic interventions that target YAP/TAZ in in both preclinical and clinical settings, as well as their prospects for use as skin cancer treatments

The approach to coronary bifurcation treatment and its outcomes in Poland: The single center experience

Background: Coronary bifurcation lesions pose therapeutic problems during percutaneous coronary interventions. The aim of this study was to analyze the strategy of coronary bifurcation treatment and associated angiographic as well as clinical outcomes in a large hospital in Northern Poland. Methods: Between January 2012 and January 2014 patients with stable coronary artery disease or non-ST-elevation acute coronary syndrome (NSTE-ACS) were treated with regular drug-eluting stents (rDES) or dedicated bifurcation stents (BiOSS Expert® or BiOSS LIM®). Clinical and angiographic controls were planned at 12 months. The primary endpoint was major adverse cardiovascular events (MACE) rate composed of cardiac death, myocardial infarction, and target lesion revascularization (TLR) at 12 months. Results: In total, 152 patients were enrolled in whom 158 stents were deployed (99 BiOSS stents and 59 rDES). Left anterior descending artery (50%) was the dominant target vessel followed by left circum¬flex (25%). There was no stent implantation failure. In 10 (6.3%) patients rDES was required within the side branch. At 12 months MACE rate was 11.2%, whereas TLR rate was 7.9%. In the logistic regression analysis final kissing balloon technique was the prognostic factor for better clinical outcome, whereas NSTE-ACS and true bifurcations were risk factors of a poor outcome. Conclusions: Percutaneous coronary bifurcation treatment is a safe and effective procedure, and pro¬visional T-stenting is the preferred technique. Both rDES as well as dedicated bifurcation stents enabled a simple and fast bifurcation treatment option with comparable MACE and TLR rates. (Cardiol J 2017; 24, 6: 589–596

Dedicated bifurcation stents or regular drug eluting stents in distal left main stenosis: A retrospective study

  Background: In the distal left main (LM) atherosclerosis mainly develops within bifurcation or trifur­cation. The aim of this study was to analyze the strategy of distal LM stenosis treatment and associated clinical outcomes in a large hospital in Northern Poland. Methods: The study population consisted of consecutive patients with stable coronary artery disease or acute coronary syndrome (ACS) and distal LM stenosis who were hospitalized between June 2012 and June 2013. Patients were treated with regular drug-eluting stents (rDES), including bioresorbable vascular scaffolds, or dedicated bifurcation stents (BiOSS LIM®). Clinical outcomes were analyzed at 12, 24 and 36 months. Primary endpoint was cumulative major adverse cardiovascular events (MACE) inducing rate of cardiac death, myocardial infarction, and target lesion revascularization (TLR) after 36 months. Results: One hundred and two patients were identified, 90 of whom were treated with percutaneous coronary intervention (56 rDES, including 9 Absorb, and 34 BiOSS) with no stent implantation fail­ure. In 15 (16.7%) patients rDES was required within side branch (SB). After 36 months MACE rate was 19.0% (BiOSS: 18.8% vs. rDES 19.2%), whereas TLR rate was 10.7% (BiOSS 12.5% vs. rDES 9.6%). In logistic regression for 36-month TLR rate proximal optimization technique (OR 0.311, 95% CI 0.211–0.644) was a prognostic factor of better clinical outcome, whereas non-ST-elevation ACS (OR 2.211, 95% CI 1.642–5.110), ST-elevation myocardial infarction (OR 2.771, 95% CI 1.325–7.209) and SB stenting (OR 1.141, 95% CI 1.002–1.881) were risk factors of poor outcome. Conclusions: Regular drug-eluting stents as well as dedicated bifurcation BiOSS LIM® stents enabled a simple and fast distal LM treatment option with a single stent. Both resulted in comparable MACE and TLR rates