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Undergraduate biology students' molecular-level understanding of stochastic (also referred to as random or noisy) processes found in biological systems is often limited to those examples discussed in class. Therefore, students frequently display little ability to accurately transfer their knowledge to other contexts. Furthermore, elaborate tools to assess students' understanding of these stochastic processes are missing, despite the fundamental nature of this concept and the increasing evidence demonstrating its importance in biology. Thus, we developed the Molecular Randomness Concept Inventory (MRCI), an instrument composed of nine multiple-choice questions based on students' most prevalent misconceptions, to quantify students' understanding of stochastic processes in biological systems. The MRCI was administered to 67 first-year natural science students in Switzerland. The psychometric properties of the inventory were analyzed using classical test theory and Rasch modeling. Moreover, think-aloud interviews were conducted to ensure response validity. Results indicate that the MRCI yields valid and reliable estimations of students' conceptual understanding of molecular randomness in the higher educational setting studied. Ultimately, the performance analysis sheds light on the extent and the limitations of students' understanding of the concept of stochasticity on a molecular level.

Environmental factors can promote phenotypic variation through alterations in the epigenome and facilitate adaptation of an organism to the environment. Although hydrogen sulfide is toxic to most organisms, the fish Poecilia mexicana has adapted to survive in environments with high levels that exceed toxicity thresholds by orders of magnitude. Epigenetic changes in response to this environmental stressor were examined by assessing DNA methylation alterations in red blood cells, which are nucleated in fish. Males and females were sampled from sulfidic and nonsulfidic natural environments; individuals were also propagated for two generations in a nonsulfidic laboratory environment. We compared epimutations between the sexes as well as field and laboratory populations. For both the wild-caught (F0) and the laboratory-reared (F2) fish, comparing the sulfidic and nonsulfidic populations revealed evidence for significant differential DNA methylation regions (DMRs). More importantly, there was over 80% overlap in DMRs across generations, suggesting that the DMRs have stable generational inheritance in the absence of the sulfidic environment. This is an example of epigenetic generational stability after the removal of an environmental stressor. The DMR-associated genes were related to sulfur toxicity and metabolic processes. These findings suggest that adaptation of P. mexicana to sulfidic environments in southern Mexico may, in part, be promoted through epigenetic DNA methylation alterations that become stable and are inherited by subsequent generations independent of the environment.

Salinity gradients act as strong environmental barriers that limit the distribution of aquatic organisms. Changes in gene expression associated with transitions between freshwater and saltwater environments can provide insights into organismal responses to variation in salinity. We used RNA-sequencing (RNA-seq) to investigate genome-wide variation in gene expression between a hypersaline population and a freshwater population of the livebearing fish species Limia perugiae (Poeciliidae). Our analyses of gill gene expression revealed potential molecular mechanisms underlying salinity tolerance in this species, including the enrichment of genes involved in ion transport, maintenance of chemical homeostasis, and cell signaling in the hypersaline population. We also found differences in gene expression patterns associated with cell-cycle and protein-folding processes between the hypersaline and freshwater L. perugiae. Bidirectional freshwater-saltwater transitions have occurred repeatedly during the diversification of fishes, allowing for broad-scale examination of repeatable patterns in evolution. Therefore, we compared transcriptomic variation in L. perugiae with other teleosts that have made freshwater-saltwater transitions to test for convergence in gene expression. Among the four distantly related population pairs from high- and low-salinity environments that we included in our analysis, we found only ten shared differentially expressed genes, indicating little evidence for convergence. However, we found that differentially expressed genes shared among three or more lineages were functionally enriched for ion transport and immune functioning. Overall, our results-in conjunction with other recent studies-suggest that different genes are involved in salinity transitions across disparate lineages of teleost fishes.

Objective Residual sequelae after surgical repair of tetralogy of Fallot (rTOF) affect clinical outcome. We investigated the prognostic impact of right ventricular (RV) dyssynchrony in adults with rTOF years after the surgical repair.Methods Patients from the Swiss Adult Congenital HEart disease Registry were included. NT-proBNP levels, echocardiography, exercise testing and MRI data were collected. An offline strain analysis to quantify RV-ventricular and interventricular dyssynchrony was performed. The standard deviation of the time-to-peak shortening (TTP) of six RV segments defined the RV Dyssynchrony Index (RVDI). Maximal difference of TTP between RV and left ventricular segments defined the interventricular shortening delay (IVSD). Predictors of a composite adverse event (arrhythmias, hospitalisation for heart failure and death) were identified by multivariate Cox regression analysis. Their median values were used to create a risk score.Results Out of 285 included patients (mean age 34±14 years), 33 patients (12%) experienced an adverse event during a mean follow-up of 48±21 months. No correlation was found between RVDI, IVSD and clinical events. NT-proBNP, right atrial area and peak heart rate were independent predictors of outcomes. After 4 years-follow-up, no adverse events occurred in patients at low risk (score=0 points), while an adverse event occurred in 62% of patients at high risk (score=3 points, p

Abstract Telomere length and telomere shortening are thought to be critical cellular attributes and processes that are related to an individual's life span and fitness. The general pattern across most taxa is that after birth telomere length gradually decreases with age. Telomere protection and restoration mechanisms are usually assumed to reduce the rate of shortening or at most keep telomere length constant. However, here we have compiled a list of 26 articles showing that there is an increasing number of studies reporting apparent elongation of telomeres (i.e., a net increase in TL from timet to timet+1) often in a considerable proportion of the individuals studied. Moreover, the few studies which have studied telomere elongation in detail show that increases in telomere length are unlikely to be due to measurement error alone. In this article, we argue that episodes of telomere elongation deserve more attention as they could reflect individual strategies to optimise life histories and maximise fitness, which may not be reflected in the overall telomere dynamics patterns. We propose that patterns of telomere (net) elongation may be partly determined by other factors than those causing telomere shortening, and therefore deserve analyses specifically targeted to investigate the occurrence of telomere elongation. We elaborate on two ecological hypotheses that have been proposed to explain patterns of telomere elongation (the ‘excess resources elongation’ and the ‘last resort elongation’ hypothesis) and we discuss the current evidence for (or against) these hypotheses and propose ways to test them.

Scientists are increasingly using volunteer efforts of citizen scientists to classify images captured by motion-activated trail cameras. The rising popularity of citizen science reflects its potential to engage the public in conservation science and accelerate processing of the large volume of images generated by trail cameras. While image classification accuracy by citizen scientists can vary across species, the influence of other factors on accuracy is poorly understood. Inaccuracy diminishes the value of citizen science derived data and prompts the need for specific best-practice protocols to decrease error. We compare the accuracy between three programs that use crowdsourced citizen scientists to process images online: Snapshot Serengeti, Wildwatch Kenya, and AmazonCam Tambopata. We hypothesized that habitat type and camera settings would influence accuracy. To evaluate these factors, each photograph was circulated to multiple volunteers. All volunteer classifications were aggregated to a single best answer for each photograph using a plurality algorithm. Subsequently, a subset of these images underwent expert review and were compared to the citizen scientist results. Classification errors were categorized by the nature of the error (e.g., false species or false empty), and reason for the false classification (e.g., misidentification). Our results show that Snapshot Serengeti had the highest accuracy (97.9%), followed by AmazonCam Tambopata (93.5%), then Wildwatch Kenya (83.4%). Error type was influenced by habitat, with false empty images more prevalent in open-grassy habitat (27%) compared to woodlands (10%). For medium to large animal surveys across all habitat types, our results suggest that to significantly improve accuracy in crowdsourced projects, researchers should use a trail camera set up protocol with a burst of three consecutive photographs, a short field of view, and determine camera sensitivity settings based on in situ testing. Accuracy level comparisons such as this study can improve reliability of future citizen science projects, and subsequently encourage the increased use of such data.

Extreme environments test the limits of life; yet, some organisms thrive in harsh conditions. Extremophile lineages inspire questions about how organisms can tolerate physiochemical stressors and whether the repeated colonization of extreme environments is facilitated by predictable and repeatable evolutionary innovations. We identified the mechanistic basis underlying convergent evolution of tolerance to hydrogen sulfide (H2S)-a toxicant that impairs mitochondrial function-across evolutionarily independent lineages of a fish (Poecilia mexicana, Poeciliidae) from H2S-rich springs. Using comparative biochemical and physiological analyses, we found that mitochondrial function is maintained in the presence of H2S in sulfide spring P. mexicana but not ancestral lineages from nonsulfidic habitats due to convergent adaptations in the primary toxicity target and a major detoxification enzyme. Genome-wide local ancestry analyses indicated that convergent evolution of increased H2S tolerance in different populations is likely caused by a combination of selection on standing genetic variation and de novo mutations. On a macroevolutionary scale, H2S tolerance in 10 independent lineages of sulfide spring fishes across multiple genera of Poeciliidae is correlated with the convergent modification and expression changes in genes associated with H2S toxicity and detoxification. Our results demonstrate that the modification of highly conserved physiological pathways associated with essential mitochondrial processes mediates tolerance to physiochemical stress. In addition, the same pathways, genes, and-in some instances-codons are implicated in H2S adaptation in lineages that span 40 million years of evolution.

Dopamine is thought to play a crucial role in cost-benefit decision making, but so far there is no consensus on the precise role of dopamine in decision making. Here, we review the literature on dopaminergic manipulations of cost-benefit decision making in humans and evaluate how well different theoretical accounts explain the existing body of evidence. Reduced D2 stimulation tends to increase the willingness to bear delay and risk costs (i.e., wait for later rewards, take riskier options), while increased D1 and D2 receptor stimulation increases willingness to bear effort costs. We argue that the empirical findings can best be explained by combining the strengths of two theoretical accounts: in cost-benefit decision making, dopamine may play a dual role both in promoting the pursuit of psychologically close options (e.g., sooner and safer rewards) and in computing which costs are acceptable for a reward at stake. Moreover, we identify several limiting factors in the study designs of previous investigations that prevented a fuller understanding of dopamine’s role in value-based choice. Together, the proposed theoretical framework and the methodological suggestions for future studies may bring us closer to a unifying account of dopamine in healthy and impaired cost-benefit decision making.

Purpose Multiparametric magnetic resonance imaging (mpMRI) targeted biopsy has emerged as an augmentation to systematic prostate biopsy (SBx) with improved diagnostic accuracy. The purpose of this study was to determine whether biopsy modality impacted management of prostate cancer (PCa). Methods We performed a retrospective review of patients with newly diagnosed non-metastatic PCa at our institution (2014–2020). Either ultrasound-guided 12-core SBx or SBx plus ≥1targeted biopsy cores from identifiable lesions on mpMRI were performed. Patients were managed with active surveillance (AS), radiation therapy (RT), or radical prostatectomy (RP). Multivariate logistic and multinomial regression analyses were performed. Results Of 578 patients, 221(38%) proceeded with AS, 121(21%) received RT, and 236(41%) underwent RP. Median age and prostate-specific antigen (PSA) were 65.4 years and 7.2 ng/mL, respectively. On multivariate analysis, biopsy type did not predict decision to pursue treatment (p=.951). On multinomial regression analysis, biopsy type did not predict selection of AS over RP (p=.973) or RT over RP (p=.813). Alternatively, age, grade group, and PSA were significant predictors of management selection. Conclusions Biopsy technique did not impact management for patients with new PCa diagnosis. Despite paradigm shifts in obtaining tissue diagnosis, age, PSA, and grade group remain valuable indices for shared decision-making and counseling patients with PCa.

Background: The long-term outcome of adults with repaired total anomalous pulmonary venous connection (TAPVC) is poorly documented. Therefore, the present study aims to provide current clinical data on adult survivors with repaired TAPVC focusing on arrhythmia. Methods: Clinical and imaging data (prevalence and type of arrhythmias, symptoms, surgical and medical treatment, echocardiographic and cardiac magnetic resonance haemodynamic parameters) were retrospectively collected from 8 European centres and compared between patients with and without arrhythmias. Results: Fifty-seven patients were included (age 20 [16-67] years [female 28, 49%]). At the last follow-up, that is, 21 (8-51) years after surgery, 79% and 93% of patients were free of symptoms and cardiac medication, respectively. The prevalence of late arrhythmias was 21%; 9 (16%) patients showed intra-atrial re-entrant tachycardia (IART) and 2 (4%) ventricular arrhythmias. Patients with IART were older (P = 0.018) and 4 (7%) required antiarrhythmic medication. Three patients (5%) underwent an electrophysiological study, and another 3 (5%) underwent pacemaker implantation within 36 months after surgical correction, which were removed in 2 patients after 7 years. Early postoperative arrhythmias (P = 0.005), right ventricular dilatation (P = 0.003), and valvulopathy (P = 0.009) were more often present in patients with late IART. Conclusions: Adult survivors after isolated-TAPVC repair presented a high prevalence of arrhythmias. Age, right ventricular dilatation, early arrhythmias, and valvular lesions are risk factors for IART. Long-term follow-up is important as some of these currently asymptomatic patients will probably develop arrhythmias in the future. Résumé: Contexte: Les résultats de santé à long terme chez les adultes ayant subi la correction d’un retour veineux pulmonaire anormal total (RVPAT) sont mal connus. Notre étude vise donc à recueillir des données cli-niques au sujet des patients ayant subi cette intervention et ayant survécu jusqu’à l’âge adulte, en particulier pour ce qui est des arythmies. Méthodologie: Les données d’observation clinique et d’imagerie (la prévalence et le type d’arythmies, les symptômes, les traitements chirurgicaux et médicaux, et les paramètres hémodynamiques obtenus par échographie et par résonance magnétique cardiaque) ont été recueillies de façon rétrospective dans huit centres européens et comparées selon que les patients présentaient ou non une arythmie. Résultats: Cinquante-sept patients ont été retenus (âge médian : 20 [16-67] ans; 28 [49 %] femmes). Au dernier suivi, soit 21 (8-51) ans après l’intervention chirurgicale, 79 % des patients ne présentaient pas de symptômes et 93 % des patients ne prenaient pas de médicaments pour des troubles cardiaques. La prévalence d’arythmies tardives s’élevait à 21 %; neuf patients (16 %) présentaient une tachycardie par réentrée intra-atriale (TRIA) et deux patients (4 %) présentaient des arythmies ventriculaires. Les patients qui présentaient une TRIA étaient plus âgés (P = 0,018) et quatre d’entre eux (7 %) devaient prendre des médicaments antiarythmiques. Trois patients (5 %) avaient subi des études électrophysiologiques et trois autres patients (5 %) avaient subi l'implantation d’un stimulateur cardiaque au cours des 36 mois suivant la correction chirurgicale; le stimulateur cardiaque a été retiré sept ans plus tard dans deux de ces cas. Les arythmies postopératoires précoces (P = 0,005), la dilation du ventricule droit (P = 0,003) et la valvulopathie (P = 0,009) étaient plus fréquentes chez les patients qui présentaient une TRIA tardive. Conclusions: La prévalence d’arythmies chez les patients survivant jusqu’à l’âge adulte après la correction isolée d’un RVPAT était élevée. L’âge, la dilation du ventricule droit, les arythmies précoces et les lésions valvulaires sont des facteurs de risque de TRIA. Il est important d’effectuer un suivi à long terme des patients ayant subi une RVPAT puisque certains d’entre eux, asymptomatiques pour le moment, présenteront sans doute des arythmies dans les années à venir.

Public Reporting (PR) of quality data is a common instrument to support transparency, accountability, and quality improvement in modern health care systems. Although, programs exist for 30 years, signals for its efficacy are inconclusive and new measurement schemes enjoy great popularity. The aim of this study was a realist view of the current literature dealing with effects of PR and finding answers on the broad and often unquestioned use by health authorities. This review considered literature from relevant databases and included all type of studies. In a kind of map, authors organized the research based on different paradigms and theories. Results indicate, first, patients rarely use the reported data. Second, providers show limited usage as well, but it is the more promising way which could lead to quality improvement. This review suggests that PR is a popular topic in different academic fields and health care policy. Despite of its high use, PR often does not show its full potential. Pure rational approaches to describe the effect of PR fall short. Further research should strive to do better by paying more attention to the breadth, theories, and context of the field as well as collective solution-finding among academia, policy, and practice.