Stable isotope analysis provides a powerful tool to identify the energy sources which fuel consumers, to understand trophic interactions and to infer consumer trophic position (TP), an important concept that describes the ecological role of consumers in food webs. However, current methods for estimating TP using stable isotopes are limited and do not fulfil the complete potential of the isotopic approach. For instance, researchers typically use point estimates for key parameters including trophic discrimination factors and isotopic baselines, and do not explicitly include variance associated with these parameters when calculating TP. We present “tRophicPosition,” anrpackage incorporating a Bayesian model for the calculation of consumer TP at the population level using stable isotopes, with one or two baselines. It combines Markov Chain Monte Carlo simulations through JAGS and statistical and graphical analyses using R. We model consumer and baseline observations using relevant statistical distributions, allowing them to be treated as random variables. The calculation of TP—a random parameter—for one baseline follows standard equations linking¹⁵N enrichment per trophic level and the trophic position of the baseline (e.g. a primary producer or primary consumer). In the case of two baselines, a simple mixing model incorporating δ¹³C allows for the differentiation between two distinct sources of nitrogen, thus including heterogeneity derived from alternatives sources of δ¹⁵N. Methods currently implemented in “tRophicPosition” include loading, plotting and summarizing stable isotope data either from multiple sites and/or communities or a local assemblage; loading trophic discrimination factors from an internal database or generating them; defining and initializing a Bayesian model of TP; sampling posterior parameters; analysing, comparing and plotting posterior estimates of TP and other parameters; and calculating a parametric (non‐Bayesian) TP estimate. Additionally, full documentation including examples, multiple vignettes and code are available for download.

Following study of the external morphology and its unmatched variability throughout ontogeny and a re-examination of selected morphological characters based on many specimens of diplomystids from Central and South Chile, we revised and emended previous specific diagnoses and considerDiplomystes chilensis,D. nahuelbutaensis,D. camposensis, andOlivaichthys viedmensis(Baker River) to be valid species. Another group, previously identified asDiplomystessp.,D. spec.,D. aff.chilensis, andD. cf.chilensisinhabiting rivers between Rapel and Itata Basins is given a new specific name (Diplomystes incognitus) and is diagnosed. An identification key to the Chilean species, including the new species, is presented. All specific diagnoses are based on external morphological characters, such as aspects of the skin, neuromast lines, and main lateral line, and position of the anus and urogenital pore, as well as certain osteological characters to facilitate the identification of these species that previously was based on many internal characters. Diplomystids below 150 mm standard length (SL) share a similar external morphology and body proportions that make identification difficult; however, specimens over 150 mm SL can be diagnosed by the position of the urogenital pore and anus, and a combination of external and internal morphological characters. According to current knowledge, diplomystid species have an allopatric distribution with each species apparently endemic to particular basins in continental Chile and one species (O. viedmensis) known only from one river in the Chilean Patagonia, but distributed extensively in southern Argentina.

Despite significant advancements in early diagnosis and treatment, breast cancer (BC) remains a major global health challenge. Ongoing research is essential to identify novel risk factors, implement innovative screening programs, and develop personalized treatment approaches. Among the various risk factors, infection with certain oncogenic viruses has emerged as a potential contributor to BC development. Increasing evidence suggests that bovine leukemia virus (BLV) may contribute to zoonotic infections in humans, with a potential role in BC initiation and progression. This review evaluates clinical and experimental data on BLV presence in both malignant and non-malignant breast tissues, exploring potential mechanisms through which BLV may access human breast tissue and contribute to carcinogenesis. Current data reveal a higher prevalence of BLV infection in BC tissues compared to non-tumor tissues, correlating with an increased risk of BC development. In this context, dairy and meat products from BLV-infected animals have been proposed as potential transmission sources. BLV-encoded proteins disrupt key oncogenic pathways, which support their possible role in breast carcinogenesis. However, the interpretation of these findings is limited by potential confounding factors such as genetic predisposition, environmental exposures, and dietary influences. Further research, including well-controlled epidemiological studies, longitudinal cohorts, and mechanistic investigations into BLV proteins in human breast cells, is necessary to determine its role in BC development.

A study including morphological characters and mitogenomics of South American and Australian fishes previously assigned to Percichthyidae was conducted. Results generated from these different data sets reveal major disagreements concerning the content and interpretation of the so-called percichthyids. A phylogenetic analysis based on 54 morphological characters suggests the existence of two major clades: (1) Percichthyidae, including the South American Percichthys and the Australian taxa Macquaria australasica, Macquaria (= Plectroplites), and Maccullochella; (2) Perciliidae with the South American genus Percilia at the base plus more advanced Australian genera Nannoperca, Nannatherina, Bostockia, and Gadopsis. In contrast, molecular and mitogenomic evidence suggests only one clade (Percichthyidae), with the exclusion of species of Macquaria (= Percalates). Additionally, the results reveal the existence of various taxonomic problems, such as the current interpretation of only one species of Percichthys in Argentina, an interpretation that is not supported by the present study; the existence of cryptic species of Percilia as well as of Gadopsis, Nannoperca, and Macquaria that will increase the diversity of the genera; and the need for an extensive revision of species previously assigned to Percalates versus Macquaria. Disagreements point to the need to develop further research on the so-called percichthyids and perciliids.