Nuclear Charge Radius of

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope ^{26m}Al. The measured isotope shift to ^{27}Al in the 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of ^{26m}Al, resulting in R_{c}=3.130(15) fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed ß decay of ^{26m}Al. Its corrected Ft value, important for the estimation of V_{ud} in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s.

Further Evidence for Shape Coexistence in

Isomers close to doubly magic _{28}^{78}Ni_{50} provide essential information on the shell evolution and shape coexistence near the Z=28 and N=50 double shell closure. We report the excitation energy measurement of the 1/2^{+} isomer in _{30}^{79}Zn_{49} through independent high-precision mass measurements with the JYFLTRAP double Penning trap and with the ISOLTRAP multi-reflection time-of-flight mass spectrometer. We unambiguously place the 1/2^{+} isomer at 942(10) keV, slightly below the 5/2^{+} state at 983(3) keV. With the use of state-of-the-art shell-model diagonalizations, complemented with discrete nonorthogonal shell-model calculations which are used here for the first time to interpret shape coexistence, we find low-lying deformed intruder states, similar to other N=49 isotones. The 1/2^{+} isomer is interpreted as the bandhead of a low-lying deformed structure akin to a predicted low-lying deformed band in ^{80}Zn, and points to shape coexistence in ^{79,80}Zn similar to the one observed in ^{78}Ni. The results make a strong case for confirming the claim of shape coexistence in this key region of the nuclear chart.

Applying machine learning methods for the analysis of two-dimensional mass spectra.

In a measurement of isomeric yield-ratios in fission, the Phase-Imaging Ion-Cyclotron-Resonance technique, which projects the radial motions of ions in the Penning trap (JYFLTRAP) onto a position-sensitive micro-channel plate detector, has been applied. To obtain the yield ratio, that is the relative population of two states of an isomer pair, a novel analysis procedure has been developed to determine the number of detected ions in each state, as well as corrections for the detector efficiency and decay losses. In order to determine the population of the states in cases where their mass difference is too small to reach full separation, a Bayesian Gaussian Mixture model was implemented. The position-dependent efficiency of the micro-channel plate detector was calibrated by mapping it with 133Cs+ ions, and a Gaussian Process was trained with the position data to construct an efficiency function that could be used to correct the recorded distributions. The obtained numbers of counts of excited and ground-state ions were used to derive the isomeric yield ratio, taking into account decay losses as well as feeding from precursors.

High-precision measurements of the hyperfine structure of cobalt ions in the deep ultraviolet range.

High-precision hyperfine structure measurements were performed on stable, singly-charged [Formula: see text]Co ions at the IGISOL facility in Jyväskylä, Finland using the collinear laser spectroscopy technique. A newly installed light collection setup enabled the study of transitions in the 230 nm wavelength range from low-lying states below 6000 cm[Formula: see text]. We report a 100-fold improvement on the precision of the hyperfine A parameters, and furthermore present newly measured hyperfine B paramaters.

Intra-dialytic intracranial pressure monitoring in a patient with lumbo-peritoneal shunt for idiopathic intracranial hypertension.

We present the case of a 25-year-old female with End-Stage Renal Disease (ESRD) and Idiopathic Intracranial Hypertension (IIH) who developed severe headaches during haemodialysis (HD). The headaches resolved several hours after each HD session. We were able to diagnose dialysis disequilibrium syndrome (DDS) following intracranial pressure (ICP) monitoring and use a novel strategy to treat her symptoms.

Impact of Nuclear Deformation and Pairing on the Charge Radii of Palladium Isotopes.

The impact of nuclear deformation can been seen in the systematics of nuclear charge radii, with radii generally expanding with increasing deformation. In this Letter, we present a detailed analysis of the precise relationship between nuclear quadrupole deformation and the nuclear size. Our approach combines the first measurements of the changes in the mean-square charge radii of well-deformed palladium isotopes between A=98 and A=118 with nuclear density functional calculations using Fayans functionals, specifically Fy(std) and Fy(Δr,HFB), and the UNEDF2 functional. The changes in mean-square charge radii are extracted from collinear laser spectroscopy measurements on the 4d^{9}5s ^{3}D_{3}→4d^{9}5p ^{3}P_{2} atomic transition. The analysis of the Fayans functional calculations reveals a clear link between a good reproduction of the charge radii for the neutron-rich Pd isotopes and the overestimated odd-even staggering: Both aspects can be attributed to the strength of the pairing correlations in the particular functional which we employ.

Evidence of a sudden increase in the nuclear size of proton-rich silver-96.

Understanding the evolution of the nuclear charge radius is one of the long-standing challenges for nuclear theory. Recently, density functional theory calculations utilizing Fayans functionals have successfully reproduced the charge radii of a variety of exotic isotopes. However, difficulties in the isotope production have hindered testing these models in the immediate region of the nuclear chart below the heaviest self-conjugate doubly-magic nucleus 100Sn, where the near-equal number of protons (Z) and neutrons (N) lead to enhanced neutron-proton pairing. Here, we present an optical excursion into this region by crossing the N = 50 magic neutron number in the silver isotopic chain with the measurement of the charge radius of 96Ag (N = 49). The results provide a challenge for nuclear theory: calculations are unable to reproduce the pronounced discontinuity in the charge radii as one moves below N = 50. The technical advancements in this work open the N = Z region below 100Sn for further optical studies, which will lead to more comprehensive input for nuclear theory development.

High-Precision Q-Value Measurement Confirms the Potential of

The ground-state-to-ground-state ß-decay Q value of ^{135}Cs(7/2^{+})→^{135}Ba(3/2^{+}) has been directly measured for the first time. The measurement was done utilizing both the phase-imaging ion-cyclotron resonance technique and the time-of-flight ion-cyclotron resonance technique at the JYFLTRAP Penning-trap setup and yielded a mass difference of 268.66(30) keV between ^{135}Cs(7/2^{+}) and ^{135}Ba(3/2^{+}). With this very small uncertainty, this measurement is a factor of 3 more precise than the currently adopted Q value in the Atomic Mass Evaluation 2016. The measurement confirms that the first-forbidden unique ß^{-}-decay transition ^{135}Cs(7/2^{+})→^{135}Ba(11/2^{-}) is a candidate for antineutrino mass measurements with an ultralow Q value of 0.44(31) keV. This Q value is almost an order of magnitude smaller than those of nuclides presently used in running or planned direct (anti)neutrino mass experiment.

Erratum: Precision Mass Measurements on Neutron-Rich Rare-Earth Isotopes at JYFLTRAP: Reduced Neutron Pairing and Implications for r-Process Calculations [Phys. Rev. Lett. 120, 262701 (2018)].

This corrects the article DOI: 10.1103/PhysRevLett.120.262701.

Variation in training requirements within general surgery: comparison of 23 countries.

Background: Many differences exist in postgraduate surgical training programmes worldwide. The aim of this study was to provide an overview of the training requirements in general surgery across 23 different countries. Methods: A collaborator affiliated with each country collected data from the country's official training body website, where possible. The information collected included: management, teaching, academic and operative competencies, mandatory courses, years of postgraduate training (inclusive of intern years), working-hours regulations, selection process into training and formal examination. Results: Countries included were Australia, Belgium, Canada, Colombia, Denmark, Germany, Greece, Guatemala, India, Ireland, Italy, Kuwait, the Netherlands, New Zealand, Russia, Saudi Arabia, South Africa, South Korea, Sweden, Switzerland, UK, USA and Zambia. Frameworks for defining the outcomes of surgical training have been defined nationally in some countries, with some similarities to those in the UK and Ireland. However, some training programmes remain heterogeneous with regional variation, including those in many European countries. Some countries outline minimum operative case requirement (range 60-1600), mandatory courses, or operative, academic or management competencies. The length of postgraduate training ranges from 4 to 10 years. The maximum hours worked per week ranges from 38 to 88 h, but with no limit in some countries. Conclusion: Countries have specific and often differing requirements of their medical profession. Equivalence in training is granted on political agreements, not healthcare need or competencies acquired during training.

Antecedentes: Existen muchas diferencias entre los programas de formación quirúrgica de posgrado del mundo. El objetivo de este estudio fue proporcionar una visión general de los requisitos formativos en cirugía general en 23 países diferentes. Métodos: En cada uno de los países participantes, un colaborador recopiló datos de la página web del organismo oficial encargado de la formación, si era posible. La información incluyó: gestión, formación, competencias académicas y operatorias, cursos obligatorios, años de formación de postgrado (que incluía el período de internado), regulaciones sobre las horas de trabajo, proceso de selección para la formación y existencia de un examen final. Resultados: Se incluyeron los datos de Australia, Bélgica, Canadá, Colombia, Dinamarca, Alemania, Grecia, Guatemala, India, Irlanda, Italia, Kuwait, Países Bajos, Nueva Zelanda, Rusia, Arabia Saudita, Sudáfrica, Corea del Sur, Suecia, Suiza, Reino Unido, Estados Unidos de América y Zambia. En algunos países existen los marcos normativos para definir los resultados del programa de formación, con ciertas semejanzas a los del Reino Unido e Irlanda. Sin embargo, algunos programas de formación, incluso en muchos países europeos, son muy heterogéneos con variaciones regionales. Pocos países describen el número mínimo de procedimientos quirúrgicos (rango 60 a 1.600), los cursos obligatorios o competencias quirúrgicas, académicos o de gestión exigidos. La duración de la formación postgraduada osciló de los 4 a los 10 años. El número de horas trabajadas máximas por semana oscilaron entre 38 y 88, sin límite en algunos países. Conclusión: Cada país tiene unos requisitos específicos, a menudo diferentes, para la formación de sus médicos. La convalidación se otorga por acuerdos políticos, más que por las necesidades médicas o por las competencias adquiridas durante la formación.

Spring-mass characteristics during human locomotion: Running experience and physiological considerations of blood lactate accumulation.

The aim of this study was to examine how running experience affects leg stiffness (Kleg) and spring-mass characteristics during running stages associated with the onset of blood lactate accumulation (OBLA). Seven trained (66.9 ± 4.8 kg; 182 ± 4.0 cm; 23.1 ± 3.1 years) and 13 untrained (78.5 ± 7.6 kg; 182 ± 3.0 cm; 20.3 ± 1.5 years) runners completed an incremental treadmill run. Running velocity was increased by 1 km.h-1 every four minutes and blood lactate samples were taken at every stage, in addition to a 10 s video recording using 'Runmatic'. Once 4 mmol L-1 (OBLA; the second lactate turn point) had been reached one more stage was completed. Spring-mass characteristics across groups and at pre-OBLA, OBLA and post-OBLA were compared. The velocity at OBLA was higher for the trained runners compared to the untrained runners (18 ± 0.7 vs 11 ± 1.3 km.h-1, p < 0.001). Kleg was similar between untrained and trained runners across each stage (15.8 ± 0.3 vs 14.3 ± 0.3 kN.m) and did not change between stages, yet spring-mass characteristics differed between groups. Vertical stiffness increased in the trained runners from pre-OBLA to post-OBLA (45.5 ± 3.35-51.9 ± 3.61 kN-1), but not in untrained runners (35.0 ± 5.2-39.6 ± 5.7 kN-1). Kleg was strongly related to Fpeak for trained runners only (r = 0.79; untrained runners, r = 0.34). Kleg was unaffected by physiological training status and was maintained across all OBLA stages. Trained runners appear to have optimised their spring-mass system in a homogenous manner, whilst less consistent spring-mass characteristics were observed in untrained runners.

Large Impact of the Decay of Niobium Isomers on the Reactor ν[over ¯]_{e} Summation Calculations.

Even mass neutron-rich niobium isotopes are among the principal contributors to the reactor antineutrino energy spectrum. They are also among the most challenging to measure due to the refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The ß-intensity distributions of ^{100gs,100m}Nb and ^{102gs,102m}Nb ß decays have been determined using the total absorption γ-ray spectroscopy technique. The measurements were performed at the upgraded Ion Guide Isotope Separator On-Line facility at the University of Jyväskylä. Here, the double Penning trap system JYFLTRAP was employed to disentangle the ß decay of the isomeric states. The new data obtained in this challenging measurement have a large impact in antineutrino summation calculations. For the first time the discrepancy between the summation model and the reactor antineutrino measurements in the region of the shape distortion has been reduced.

The Cloacal Microbiome Changes with the Breeding Season in a Wild Bird.

The symbiotic microbial communities, or "microbiomes," that reside on animals are dynamic, and can be affected by the behavior and physiology of the host. These communities provide many critical beneficial functions for their hosts, but they can also include potential pathogens. In birds, bacteria residing in the cloaca form a complex community, including both gut and sexually-transmitted bacteria. Transmission of cloacal bacteria among individuals is likely during the breeding season, when there is direct cloacal contact between individuals. In addition, the major energetic investment in reproduction can draw resources away from immune responses that might otherwise prevent the successful establishment of microbes. We assessed dynamic variation in the cloacal microbiome of free-living rufous-collared sparrows (Zonotrichia capensis) through sequential breeding and non-breeding seasons. We found that the cloacal bacterial communities differed between the sexes when they were in breeding condition. Further, in males, but not in females, the bacterial community became more diverse with the onset of reproduction, and then decreased in diversity as males transitioned to non-breeding condition. Individuals sampled across sequential breeding seasons did not accumulate more bacterial taxa over seasons, but bacterial community composition did change. Our results suggest that the cloacal microbiome in birds is dynamic and, especially in males, responsive to breeding condition.

Glucocorticoids and "Stress" Are Not Synonymous.

Reference to glucocorticoids as "stress hormones" has been growing in prevalence in the literature, including in comparative and environmental endocrinology. Although glucocorticoids are elevated in response to a variety of stressors in vertebrate animals, the primary functions of glucocorticoids are not responding to stressors and they are only one component of complex suite of physiological and behavioral responses to stressors. Thus, the use of the short-hand phrase "stress hormone" can be misleading. Further, simply measuring glucocorticoids is not equivalent to measuring a stress response, nor is manipulating glucocorticoids equivalent to exposing an animal to a stressor. In this commentary we highlight the problems with using functional names for hormones, and of treating cortisol or corticosterone as synonymous with stress. We provide recommendations to add clarity to the presentation of research on this topic, and to avoid conflation of glucocorticoids with stressors and the stress response in the design of experiments.

Los Glucocorticoides y el "Estrés" no Son Sinónimos (Glucocorticoids and "Stress" Are Not Synonymous) La referencia a los glucocorticoides como "hormonas del estrés" ha aumentado en prevalencia en la literatura, incluso en endocrinología comparativa y ecológica. Aunque los glucocorticoides están elevados en respuesta a una variedad de factores de estrés en animales vertebrados, las funciones primarias de los glucocorticoides no responden a los factores de estrés y son solo un componente de un conjunto complejo de respuestas fisiológicas y de comportamiento a los factores de estrés. Por lo tanto, el uso de la frase abreviada "hormona del estrés" puede ser engañoso. Además, simplemente medir glucocorticoides no es equivalente a medir una respuesta al estrés, ni manipular glucocorticoides equivalente a exponer a un animal a un factor estresante. En este comentario destacamos los problemas con el uso de nombres funcionales para las hormonas y con el tratamiento del cortisol o la corticosterona como sinónimo de estrés. Brindamos recomendaciones para agregar claridad a la presentación de investigaciones sobre este tema y para evitar la combinación de glucocorticoides con factores estresantes y la respuesta al estrés en el diseño de los experimentos. Translated to Spanish by J. Heras (herasj01@gmail.com).

Glucocorticóides e "Stress" Não São Sinônimos (Glucocorticoids and "Stress" Are Not Synonymous) A referência aos glicocorticóides como "hormônios do estresse" vem se tornando prevalente em literatura, inclusive na endocrinologia comparada e ecológica. Embora os glicocorticóides sejam elevados em resposta a uma variedade de estressores em vertebrados, as funções primárias de glicocorticóides são a de não responder aos causadores do stress e eles são apenas um componente dentro de um complexo conjunto de respostas fisiológicas e comportamentais aos estressores. Assim, o uso da frase curta "hormônio do estresse" pode ser errôneo. Além disso, simplesmente medir glicocorticóides não é equivalente a medir uma resposta ao estresse, nem a manipulação de glicocorticoides é equivalente a expor um animal a um estressor. Neste comentário, destacamos os problemas com o uso de nomes funcionais para hormônios e o tratamento de cortisol ou corticosterona como sinônimos de estresse. Nós provemos recomendações para adicionar clareza à apresentação de pesquisas deste tópico e para evitar a o tratamento direto de glicocorticoides como estressores e a resposta ao estresse no planejamento de experimentos. Translated to Portuguese by Diego Vaz (dbistonvaz@vims.edu).

A Mathematical Modeling Approach to the Cort-Fitness Hypothesis.

The Cort-Fitness Hypothesis has generated much interest from investigators integrating field endocrinology with evolutionary biology, ecology, and conservation. The hypothesis was developed to test the assumption that if glucocorticoid levels increase with environmental challenges and fitness decreases with environmental challenges, then there should be a negative relationship between baseline glucocorticoid levels and fitness. Indeed, studies across diverse taxa have found that the relationship between baseline glucocorticoid levels and fitness are not consistent: some studies show a positive relationship, others negative, and some show no correlation. Hence, a deeper understanding of the mechanisms underlying the relationship between baseline glucocorticoid levels, environmental challenges, and fitness is needed. We propose a mathematical model representing the links between baseline glucocorticoid levels, environmental challenges, and fitness. Our model describes how variation in the predictability and intensity of environmental challenges, reproductive strategies, and fitness metrics can all contribute to the variability observed in empirical tests of the Cort-Fitness Hypothesis. We provide qualitative results showing that much of the inconsistency in previous studies can be explained and we discuss how the model can be used to inform future Cort-Fitness studies.

Un enfoque de modelado matemático para la hipótesis de Cort-Fitness (A Mathematical Modeling Approach to The Cort-Fitness Hypothesis) La hipótesis de Cort-Fitness ha generado mucho interés por parte de los investigadores que integran la endocrinología de campo con la biología evolutiva, la ecología y la conservación. La hipótesis se desarrolló para probar el supuesto de que si los niveles de glucocorticoides aumentan con los desafíos ambientales y la aptitud física disminuye con los ambientales, entonces debería existir una relación negativa entre los niveles de glucocorticoides de referencia y la aptitud física. De hecho, los estudios en diversos taxones han encontrado que la relación entre los niveles de glucocorticoides de referencia y la aptitud no son consistentes: algunos estudios muestran una relación positiva, otros negativos y otros no muestran correlación. Por lo tanto, se necesita una comprensión más profunda de los mecanismos subyacentes en la relación entre los niveles de glucocorticoides de referencia, los desafíos ambientales y la aptitud. Proponemos un modelo matemático que representa los vínculos entre los niveles basales de glucocorticoides, los desafíos ambientales y la aptitud. Nuestro modelo describe cómo la variación en la previsibilidad e intensidad de los desafíos ambientales, las estrategias reproductivas y las métricas de aptitud pueden contribuir a la variabilidad observada en las pruebas empíricas de la hipótesis de Cort-Fitness. Proporcionamos resultados cualitativos que muestran que gran parte de la variación en estudios anteriores se puede explicar y discutimos cómo se puede usar el modelo para informar futuros estudios de Cort-Fitness. Translated to Spanish by J Heras (herasj01@gmail.com).

Uma Abordagem Matématica de Modelagem para a Hipótese Cort-Fitness (A Mathematical Modeling Approach to The Cort-Fitness Hypothesis) A hipótese de cort-fitness gerou muito interesse de pesquisadores ao integrar endocrinologia de campo com biologia evolutiva, ecologia e conservação. A hipótese foi desenvolvida para testar a suposição de que, se os níveis de glicocorticóides aumentam com os desafios ambientais e o fitness diminui, então deve haver uma relação negativa entre os níveis basais de glicocorticóides e o fitness. De fato, estudos com diversos táxons descobriram que a relação entre os níveis basais de glicocorticoides e o fitness não são consistentes: alguns mostram uma relação positiva, outros uma negativa e há ainda os que não mostram correlação alguma. Assim, é necessária uma compreensão mais profunda dos mecanismos subjacentes à relação entre os níveis basais de glicocorticóides, os desafios ambientais e o fitness. Propomos um modelo matemático que representa as ligações entre os níveis basais de glicocorticoides, os desafios ambientais e o fitness. Nosso modelo descreve como a variação na previsibilidade e intensidade dos desafios ambientais, estratégias reprodutivas e métricas de fitness podem contribuir para a variabilidade observada nos testes empíricos da hipótese cort-fitness. Nós fornecemos resultados qualitativos mostrando que grande parte da variação em estudos anteriores pode ser explicada e discutimos como o modelo pode ser usado para informar futuros estudos sobre o cort-fitness. Translated to Portuguese by G Sobral (gabisobral@).

Discovery of an Exceptionally Strong ß-Decay Transition of

A significant fraction of stars between 7 and 11 solar masses are thought to become supernovae, but the explosion mechanism is unclear. The answer depends critically on the rate of electron capture on ^{20}Ne in the degenerate oxygen-neon stellar core. However, because of the unknown strength of the transition between the ground states of ^{20}Ne and ^{20}F, it has not previously been possible to fully constrain the rate. By measuring the transition, we establish that its strength is exceptionally large and that it enhances the capture rate by several orders of magnitude. This has a decisive impact on the evolution of the core, increasing the likelihood that the star is (partially) disrupted by a thermonuclear explosion rather than collapsing to form a neutron star. Importantly, our measurement resolves the last remaining nuclear physics uncertainty in the final evolution of degenerate oxygen-neon stellar cores, allowing future studies to address the critical role of convection, which at present is poorly understood.

Tales of testosterone: Advancing our understanding of environmental endocrinology through studies of neotropical birds.

Studies of birds have greatly advanced our understanding of how testosterone modulates complex phenotypes, specifically its role in mediating male reproductive and associated behaviors. Yet most of the foundational studies have been limited to northern latitude breeding species despite the fact that they represent only a small fraction of worldwide avian diversity. In contrast, phylogenetic, life-history, and mating system diversity all reach their apex in neotropical avifauna and yet these birds, along with more southern latitude species, remain very poorly understood from an endocrine perspective. Despite the relatively limited previous work on taxa breeding in Central and South America, empirical findings have had a disproportionately large impact on our understanding of testosterone's role in everything from geographic variation to behavioral roles and neuroplasticity. Here, we synthesize how studies of neotropical breeding avifauna have advanced our understanding of how testosterone's actions can and are associated with the broad patterns of phenotypic diversity that we see in birds. In addition, we outline how these studies can be used individually or in a comparative context to address fundamental questions about the environmental endocrinology of testosterone and to understand the diversity of roles that testosterone plays in mediating behavioral variation, reproductive strategies, and associated life-history trade-offs.

Precision Mass Measurements on Neutron-Rich Rare-Earth Isotopes at JYFLTRAP: Reduced Neutron Pairing and Implications for r-Process Calculations.

The rare-earth peak in the r-process abundance pattern depends sensitively on both the astrophysical conditions and subtle changes in nuclear structure in the region. This work takes an important step towards elucidating the nuclear structure and reducing the uncertainties in r-process calculations via precise atomic mass measurements at the JYFLTRAP double Penning trap. ^{158}Nd, ^{160}Pm, ^{162}Sm, and ^{164-166}Gd have been measured for the first time, and the precisions for ^{156}Nd, ^{158}Pm, ^{162,163}Eu, ^{163}Gd, and ^{164}Tb have been improved considerably. Nuclear structure has been probed via two-neutron separation energies S_{2n} and neutron pairing energy metrics D_{n}. The data do not support the existence of a subshell closure at N=100. Neutron pairing has been found to be weaker than predicted by theoretical mass models. The impact on the calculated r-process abundances has been studied. Substantial changes resulting in a smoother abundance distribution and a better agreement with the solar r-process abundances are observed.

The influence of aquaculture unit proximity on the pattern of Lepeophtheirus salmonis infection of anadromous Salmo trutta populations on the isle of Skye, Scotland.

A total of 230 anadromous Salmo trutta (brown trout) were sampled in five sheltered coastal fjords (or sea lochs) on the Isle of Skye, Scotland, U.K., in 2016 at varying distances from active Atlantic salmon Salmo salar farms. Statistical models were developed to investigate potential correlations between salmon lice Lepeophtheirus salmonis burdens on S. trutta hosts and their proximity to S. salar farm cages. Significant correlations were found between lice burdens and fish fork length and proximity to the nearest S. salar farm. The probability of the presence of L. salmonis on fish hosts increased with fish host size and with distance from the nearest S. salar farm, but total lice burdens were highest in fish sampled near S. salar farms and decreased with distance. The proportion of different life-cycle stages of L. salmonis were also dependent on S. salar farm proximity, with higher juvenile lice numbers recorded at sites near S. salar farm cages. These results highlight the complexity of the relationship between S. trutta and L. salmonis infections on wild fish and emphasize the requirement of further research to quantify these effects to better inform conservation and management strategies, particularly in areas of active S. salar farm facilities.