On vertex coloring without monochromatic triangles

We study a certain relaxation of the classic vertex coloring problem, namely, a coloring of vertices of undirected, simple graphs, such that there are no monochromatic triangles. We give the first classification of the problem in terms of classic and parametrized algorithms. Several computational complexity results are also presented, which improve on the previous results found in the literature. We propose the new structural parameter for undirected, simple graphs -- the triangle-free chromatic number $\chi_3$. We bound $\chi_3$ by other known structural parameters. We also present two classes of graphs with interesting coloring properties, that play pivotal role in proving useful observation about our problem. We give/ask several conjectures/questions throughout this paper to encourage new research in the area of graph coloring.Comment: Extended abstrac

Can agentic messages help?: Linguistic strategies to counteract voice‐based sexual orientation discrimination

Gay men who believe to sound ‘gay’ expect to be discriminated against because of their voices and gay-sounding men are discriminated against in the hiring process. We examined whether uttering an agency-based message decreased discrimination expectancy and enactment. In Study 1a (N = 256; gay and bisexual men) and Study 1b (N = 216; gay men), speakers uttered agentic (vs. neutral) messages. We assessed their self-perception as gay sounding, agency self-attribution and discrimination expectancy. Uttering agentic (vs. neutral) messages made the speakers self-perceive as more agentic and this decreased discrimination expectancy. Additionally, self-perception as gay sounding predicted discrimination expectancy. In Study 2 (N = 466), heterosexual participants listened to gay- and straight-sounding speakers uttering either neutral or agentic messages and rated them in terms of agency and employability. Gay-sounding speakers uttering agentic messages were less likely to be discriminated against than when uttering neutral messages. Results show the positive impact of linguistic strategies involving agentic messages to reduce discrimination expectancy and hiring biases.info:eu-repo/semantics/acceptedVersio

Transferrin changes in haemodialysed patients

Transferrin (Tf) is a glycoprotein responsible for iron transport in the human body. Physiologically in reaction with Concanavalin A, Tf occurs in four distinct variants Tf1, Tf2, Tf3 (apo-Tf) and Tf4. It was reported recently that Tf is changing, particularly during acute phase response, taking place among others in end-stage renal disease. In this study, we wanted to find the answer to three main questions: firstly, how Tf is changing in patients treated with maintenance haemodialysis (mHD), secondly, whether there are any Tf changes in the course of mHD treatment, and thirdly, what factors can affect Tf microheterogeneity in these patients. Studies were performed on 80 haemodialysed patients and 21 healthy volunteers. The Tf concentration was determined by the rocket immunoelectrophoresis, and its microheterogeneity was assessed by the ConA crossed immunoaffinity electrophoresis. During the annual observation of the distribution of the Tf variants, we have found both changes of the percentage contents of all Tf variants in the whole Tf concentration and a significant decrease in Tf2, Tf3 and Tf4 serum concentrations. Moreover, we found that decrease in the renal function, duration of mHD, and inflammation may contribute to these above-mentioned changes, which are probably the factors that should be taken into account when explaining the mechanisms of persistence of anaemia in haemodialysed patients

Skin detachment from salmon and rainbow trout

A survey aimed at relevant stakeholders highlighted loose skin as a quality concern since 2019. The issue is typically detected after storage, with indications of higher prevalence during late spring-summer in Southern-West regions, while during late summer-autumn in Northern regions. The issue seems transient, i.e. skin seems to reattach after a period. Industry statistics and experiments found no correlation between common delousing methods and loose skin. Stress prevention is crucial for fish welfare, also given the observed vulnerability of the adipose tissue under the skin to collapsing under mechanical pressure. In each case of loose skin, a glossy liquid was found between the skin and muscle, being mainly composed of fat (69%), with a higher content of 18:1n-9 and 18:2n-6 (found in plant oils), and a lower content of 22:6n-3 (found in fish oil), compared with the skeletal muscle. Also, the amino acid composition varied, indicating selective leakage. We were unable to obtain rainbow trout with loose skin, but surprisingly large differences in collagen composition were found between the species. No indications of increased activity of degrading enzymes were detected, but the extent of lipid peroxidation was higher in salmon with loose skin compared with salmon with reattached skin, as well as in soft muscle in contrast to firm muscle. Microscopic examinations did not reveal any explicit signs of abnormal connective tissue structure in salmon with loose skin. Instead, variations in the morphology of myofibers were observed. Further, transcriptomics revealed substantial changes in the muscle transcriptome, including a large array of inflammatory genes in fish with loose skin. It is concluded that the issue of loose skin arises while the fish is alive, is associated with soft muscle, and becomes apparent after a certain period post-slaughter. In addition to novel knowledge on loose skin, the project provided useful knowledge that can be utilized in future research on soft texture and fillet gaping.publishedVersio

Skin detachment from salmon and rainbow trout

A survey aimed at relevant stakeholders highlighted loose skin as a quality concern since 2019. The issue is typically detected after storage, with indications of higher prevalence during late spring-summer in Southern-West regions, while during late summer-autumn in Northern regions. The issue seems transient, i.e. skin seems to reattach after a period. Industry statistics and experiments found no correlation between common delousing methods and loose skin. Stress prevention is crucial for fish welfare, also given the observed vulnerability of the adipose tissue under the skin to collapsing under mechanical pressure. In each case of loose skin, a glossy liquid was found between the skin and muscle, being mainly composed of fat (69%), with a higher content of 18:1n-9 and 18:2n-6 (found in plant oils), and a lower content of 22:6n-3 (found in fish oil), compared with the skeletal muscle. Also, the amino acid composition varied, indicating selective leakage. We were unable to obtain rainbow trout with loose skin, but surprisingly large differences in collagen composition were found between the species. No indications of increased activity of degrading enzymes were detected, but the extent of lipid peroxidation was higher in salmon with loose skin compared with salmon with reattached skin, as well as in soft muscle in contrast to firm muscle. Microscopic examinations did not reveal any explicit signs of abnormal connective tissue structure in salmon with loose skin. Instead, variations in the morphology of myofibers were observed. Further, transcriptomics revealed substantial changes in the muscle transcriptome, including a large array of inflammatory genes in fish with loose skin. It is concluded that the issue of loose skin arises while the fish is alive, is associated with soft muscle, and becomes apparent after a certain period post-slaughter. In addition to novel knowledge on loose skin, the project provided useful knowledge that can be utilized in future research on soft texture and fillet gaping.publishedVersio

Trust predicts COVID-19 prescribed and discretionary behavioral intentions in 23 countries

The worldwide spread of a new coronavirus (SARS-CoV-2) since December 2019 has posed a severe threat to individuals well-being. While the world at large is waiting that the released vaccines immunize most citizens, public health experts suggest that, in the meantime, it is only through behavior change that the spread of COVID-19 can be controlled. Importantly, the required behaviors are aimed not only at safeguarding one s own health. Instead, individuals are asked to adapt their behaviors to protect the community at large. This raises the question of which social concerns and moral principles make people willing to do so. We considered in 23 countries (N = 6948) individuals willingness to engage in prescribed and discretionary behaviors, as well as country-level and individual-level factors that might drive such behavioral intentions. Results from multilevel multiple regressions, with country as the nesting variable, showed that publicized number of infections were not significantly related to individual intentions to comply with the prescribed measures and intentions to engage in discretionary prosocial behaviors. Instead, psychological differences in terms of trust in government, citizens, and in particular toward science predicted individuals behavioral intentions across countries. The more people endorsed moral principles of fairness and care (vs. loyalty and authority), the more they were inclined to report trust in science, which, in turn, statistically predicted prescribed and discretionary behavioral intentions. Results have implications for the type of intervention and public communication strategies that should be most effective to induce the behavioral changes that are needed to control the COVID-19 outbreak

Hepatitis C virus quasispecies in chronically infected children subjected to interferon–ribavirin therapy

Accumulating evidence suggests that certain features of hepatitis C virus (HCV), especially its high genetic variability, might be responsible for the low efficiency of anti-HCV treatment. Here, we present a bioinformatic analysis of HCV-1a populations isolated from 23 children with chronic hepatitis C (CHC) subjected to interferon–ribavirin therapy. The structures of the viral quasispecies were established based on a 132-amino-acid sequence derived from E1/E2 protein, including hypervariable region 1 (HVR1). Two types of HCV populations were identified. The first type, found in non-responders, contained a small number of closely related variants. The second type, characteristic for sustained responders, was composed of a large number of distantly associated equal-rank variants. Comparison of 445 HVR1 sequences showed that a significant number of variants present in non-responding patients are closely related, suggesting that certain, still unidentified properties of the pathogen may be key factors determining the result of CHC treatment

Naturally occurring variation in tadpole morphology and performance linked to predator regime

Divergent natural selection drives a considerable amount of the phenotypic and genetic variation observed in natural populations. For example, variation in the predator community can generate conflicting selection on behavioral, life-history, morphological, and performance traits. Differences in predator regime can subsequently increase phenotypic and genetic variations in the population and result in the evolution of reproductive barriers (ecological speciation) or phenotypic plasticity. We evaluated morphology and swimming performance in field collected Bronze Frog larvae (Lithobates clamitans) in ponds dominated by predatory fish and those dominated by invertebrate predators. Based on previous experimental findings, we hypothesized that tadpoles from fish-dominated ponds would have small bodies, long tails, and large tail muscles and that these features would facilitate fast-start speed. We also expected to see increased tail fin depth (i.e., the tail-lure morphology) in tadpoles from invertebrate-dominated ponds. Our results support our expectations with respect to morphology in affecting swimming performance of tadpoles in fish-dominated ponds. Furthermore, it is likely that divergent natural selection is playing a role in the diversification on morphology and locomotor performance in this system

Effects of Psychological Distance on Mental Abstraction: A Registered Report of Four Tests of Construal Level Theory

Construal level theory (CLT) proposes that psychological distance influences the level of abstraction at which something is mentally construed: things perceived as less probable (likelihood) or further away from the here (spatial distance), now (temporal distance), or self (social distance) are thought about more abstractly. This international multi-lab study tests four basic hypotheses derived from core assumptions of CLT and explores potential moderators and boundary conditions of the effects. Participants (N = 11,775) from 27 countries and regions were randomly assigned to one of four experimental protocols focused on different types of psychological distance (temporal, spatial, social, or likelihood), and each experiment manipulated psychological distance (close vs. distant). The protocols for temporal distance (N = 2,941) and spatial distance (N = 2,973) were direct replications of Liberman and Trope (1998, Study 1) and Fujita et al. (2006, Study 1), respectively. The remaining two protocols were paradigmatic replications, applying to social distance (N = 2,926) and likelihood (N = 2,936). The effects of psychological distance on construal level for the four present studies were (original effects within parentheses; positive effects are consistent with hypotheses): dtemporal = 0.08, 95% CI [0.003, 0.16] (cf. d = 0.92); dspatial = 0.04, 95% CI [-0.03, 0.11] (cf. d = 0.55); dsocial = -0.27, 95% CI [-0.34, -0.19]; and dlikelihood = 0.03, 95% CI [-0.05, 0.11]. Pretests indicated that valence and abstraction were confounded in response options on the outcome measure. Controlling for this confound eliminated the hypothesis-inconsistent effect of social distance, d = 0.006, 95% CI [-0.05, 0.07]. These findings provide limited evidence for the predictions of the theory and present a critical challenge for CLT