Invariant elliptic curves as attractors in the projective plane

Let f be a rational self-map of P^2 which leaves invariant an elliptic curve C with strictly negative transverse Lyapunov exponent. We show that C is an attractor, i.e. it possesses a dense orbit and its basin is of strictly positive measure

Understanding the use of media analysis in public health research through food tax debates (HEALTHEI Project): a scoping review. UK Public Health Science Conference 24th November 2023

Background: Poor diet is a major public health concern. In 2021, 63·8% of adults and 22·2% of reception-age children were either overweight or obese in England. Fiscal interventions have become a popular policy measure to reduce obesity and encourage healthy eating. Such measures are highly controversial, leading to media debate promoting pro-tax and anti-tax arguments. To better understand food tax debates and the use of media analysis in public health research, we conducted a scoping review of media analyses using food taxes as a case study. Methods: In this scoping review, we searched SCOPUS, PubMed and EBSCOhost databases on Feb 14–22, 2023, using keyword variations for “food”, “tax” and “media analysis”. Results were restricted to English-only, peer-reviewed journal articles. The initial results were manually screened through an iterative process to exclude articles that did not analyse a food tax, were non-English language, were not peer-reviewed and/or did not use media analysis as the primary method. Modelled on Arksey and O’Malley’s (2005) five-stage review protocol, two researchers used a coding framework to independently code all articles and checked result quality through regular discussion. Extracted data included article title, author, year, country, tax type, media sources used, identified media frames, and research aims, methods, results, and conclusions. Results are reported according to PRISMA guidelines and data files submitted to FigShare Repository (non-accessible). Findings: Of 1087 articles reviewed, 19 were eligible to be included in the study. Articles were published between 2013 and 2023, with 2021 having the highest concentration of studies carried out mainly in the UK and USA. Despite search terms encompassing a range of food products, the retrieved media analyses focused on three types of food product taxes: sugar-sweetened beverages (SSB), meat, and groceries. Most articles explored arguments for and against policy implementation, with some investigating stakeholder representation. Results demonstrate that stakeholders’ arguments, both positive and negative, are consistent across countries and food products. Interpretation: The consistency of how both pro-tax and anti-tax arguments are presented in the media demonstrates the importance of coordination between stakeholder groups to influence policy adoption. To our knowledge, this is the first study to investigate media analysis across a diverse range of food products

Epitope tagging of endogenous genes in diverse human cell lines

Epitope tagging is a powerful and commonly used approach for studying the physical properties of proteins and their functions and localization in eukaryotic cells. In the case of Saccharomyces cerevisiae, it has been possible to exploit the high efficiency of homologous recombination to tag proteins by modifying their endogenous genes, making it possible to tag virtually every endogenous gene and perform genome-wide proteomics experiments. However, due to the relative inefficiency of homologous recombination in cultured human cells, epitope-tagging approaches have been limited to ectopically expressed transgenes, with the attendant limitations of their nonphysiological transcriptional regulation and levels of expression. To overcome this limitation, a modification and extension of adeno-associated virus-mediated human somatic cell gene targeting technology is described that makes it possible to simply and easily create an endogenous epitope tag in the same way that it is possible to knock out a gene. Using this approach, we have created and validated human cell lines with epitope-tagged alleles of two cancer-related genes in a variety of untransformed and transformed human cell lines. This straightforward approach makes it possible to study the physical and biological properties of endogenous proteins in human cells without the need for specialized antibodies for individual proteins of interest

Expression and activity profiles of DPP IV/CD26 and NEP/CD10 glycoproteins in the human renal cancer are tumor-type dependent

[Background] Cell-surface glycoproteins play critical roles in cell-to-cell recognition, signal transduction and regulation, thus being crucial in cell proliferation and cancer etiogenesis and development. DPP IV and NEP are ubiquitous glycopeptidases closely linked to tumor pathogenesis and development, and they are used as markers in some cancers. In the present study, the activity and protein and mRNA expression of these glycoproteins were analysed in a subset of clear-cell (CCRCC) and chromophobe (ChRCC) renal cell carcinomas, and in renal oncocytomas (RO).[Methods] Peptidase activities were measured by conventional enzymatic assays with fluorogen-derived substrates. Gene expression was quantitatively determined by qRT-PCR and membrane-bound protein expression and distribution analysis was performed by specific immunostaining.Peer reviewe

The Geometry of the Critically Periodic Curves in the Space of Cubic Polynomials

We provide an algorithm for computing the Euler characteristic of the curves in consisting of all polynomials with a periodic critical point of period p in the space of critically marked complex cubic polynomials. The curves were introduced in [Milnor 09, Bonifant etal. 10], and the algorithm applies the main results of [DeMarco and Pilgrim 11b]. The output is shown for periods p <= 26