An outbreak of SARS-CoV-2 was confirmed after an academic party in Helsinki, Finland, in 2022. All 70 guests were requested to fill in follow-up questionnaires; serologic analyses and whole-genome sequencing (WGS) were conducted when possible.

Of those participating – all but one with ≥3 vaccine doses – 21/53 (40%) had test-confirmed symptomatic COVID-19: 7% of those with earlier episodes and 76% of those without. Half (11/21) were febrile, but none needed hospitalisation. WGS revealed subvariant BA.2.23.

Compared to vaccination alone, our data suggest remarkable protection by hybrid immunity against symptomatic infection, particularly in instances of recent infections with homologous variants.

Design representations are important tools for designers in the design process. To help designers choose the appropriate representation, taxonomies have been proposed based on type, degree of fidelity, and when to use them. However, Design representations may also play an important role in designers' communication with users and enabling users as co-designers. Therefore, new taxonomies, focusing on design representations’ potential mediating roles in collaborative design processes with users, have been developed. The purpose of this interview study, with twelve designers within Swedish industry, was thus to investigate how designers use design representations in communication with users in the design process. The study indicates that the designers mainly interacted with users in order for them to answer specific design questions or to evaluate design solutions. If design representations’ value for facilitating communication and collaboration with users should be emphasized, we need to shift from teaching mainly taxonomies related to fidelity levels or when to use them in the design process, and rather educate future designers about design representations inherent potential to mediate and enhance the dialogue with users.

In order to better understand the stakeholder choices of knowledge-based organisational actors, this study focuses on a novel application of Huber's (2012) dimensions of proximity salience, namely spatial proximity, social proximity and cognitive proximity. The population of the study is made up of knowledge-based organisational actors involved in developing an innovation ecosystem, in terms of stakeholder network creation. The extent to which the three proximity dimensions of stakeholder salience is evident in the stakeholder choices of these innovation-focused actors seeking knowledge-based collaborators is explored. Our findings show how various forms of proximity prompt the decision of who to work with among a diverse population of experts involved in building a cross-national innovation ecosystem. The various explanations that motivate stakeholder choice matched Huber's proximity dimensions. The findings provide new insight into stakeholder choice among knowledge-based organisations, and highlight a new proximity dimension indirectly linked to cognition proximity. Termed the “potential proximity” dimension, it involves attraction to stakeholders that represent strategic value.

We use historical census data to show that Sweden exhibited high levels of intergenerational occupational mobility several decades before the rise of the welfare state. Mobility rates were higher than in other nineteenth- and twentieth-century European countries, closer to those observed in the highly mobile nineteenth-century United States. We leverage mobility variation across Swedish municipalities to shed light on potential determinants: economic growth and migration are positively correlated with mobility, consistent with the patterns observed across countries.

The bacterium Neisseria meningitidis causes life-threatening disease worldwide, typically with a clinical presentation of sepsis or meningitis, but can be carried asymptomatically as part of the normal human oropharyngeal microbiota. The aim of this study was to examine N. meningitidis carriage with regard to prevalence, risk factors for carriage, distribution of meningococcal lineages and persistence of meningococcal carriage. Throat samples and data from a self-reported questionnaire were obtained from 2744 university students (median age: 23 years) at a university in Sweden on four occasions during a 12-month period. Meningococcal isolates were characterised using whole-genome sequencing. The carriage rate among the students was 9.1% (319/3488; 95% CI 8.2–10.1). Factors associated with higher carriage rate were age ≤22 years, previous tonsillectomy, cigarette smoking, drinking alcohol and attending parties, pubs and clubs. Female gender and sharing a household with children aged 0–9 years were associated with lower carriage. The most frequent genogroups were capsule null locus (cnl), group B and group Y and the most commonly identified clonal complexes (cc) were cc198 and cc23. Persistent carriage with the same meningococcal strain for 12 months was observed in two students. Follow-up times exceeding 12 months are recommended for future studies investigating long-term carriage of N. meningitidis.

Iodine deficiency may cause thyroid dysfunction. The iodine intake in a population is measured by urinary iodine concentration (UIC) in spot samples or 24-h urinary iodine excretion (24UIE). 24UIE is considered the gold standard and may be estimated using an equation including UIC, urinary creatinine concentration, sex and age (e24UIE). The aims of this study were to evaluate the preferable timing of UIC when using this equation and assess the variability of UIE. Sixty healthy non-smoking women (n 31) and men (n 29) were included in Gothenburg, Sweden. Twelve urine samples were collected at six fixed times on two separate days. Variability was calculated for UIC, 24UIE, e24UIE, iodine excretion per hour (iHr) and UIC adjusted for creatinine and specific gravity. Median 24UIE was 156 µg/24 h and the median UIC (all spot samples) was 104 µg/l. UIC (P < 0·001), 24UIE (P = 0·001) and e24UIE (P < 0·001) were significantly higher in men. e24UIE was relatively similar to 24UIE. However, when e24UIE was calculated from UIC in the first void, it was about 15 % lower than 24UIE (P < 0·001). iHr was lowest in the morning and highest in the afternoon. Median iHr was higher in men (7·4 v. 5·3 µg/h, P < 0·001). The variability of UIE was higher within individuals than between individuals. This study suggests that most time points for estimation of individual 24UIE are appropriate, but they should preferably not be collected in the first void.

Mathematics is a fundamental tool of research. Although potentially applicable in every discipline, the amount of training in mathematics that students typically receive varies greatly between different disciplines. In those disciplines where most researchers do not master mathematics, the use of mathematics may be held in too much awe. To demonstrate this I conducted an online experiment with 200 participants, all of which had experience of reading research reports and a postgraduate degree (in any subject). Participants were presented with the abstracts from two published papers (one in evolutionary anthropology and one in sociology). Based on these abstracts, participants were asked to judge the quality of the research. Either one or the other of the two abstracts was manipulated through the inclusion of an extra sentence taken from a completely unrelated paper and presenting an equation that made no sense in the context. The abstract that included the meaningless mathematics tended to be judged of higher quality. However, this “nonsense math effect” was not found among participants with degrees in mathematics, science, technology or medicine.

A gender difference in risk preferences, with women being more averse to risky choices, is a robust experimental finding. Speculating on the sources of this difference, Croson and Gneezy recently pointed to the tendency for women to experience emotions more strongly and suggested that feeling more strongly about negative outcomes would lead to greater risk-aversion. Here we test this hypothesis in an international survey with 424 respondents from India and 416 from US where we ask questions about a hypothetical lottery. In both countries we find that emotions about outcomes are stronger among women, and that this effect partially mediates gender difference in willingness to enter the lottery.

Although cats are extremely common, pet owners seem to have a poor understanding of their natural behaviour and needs and a large number end up in cat shelters. In Sweden, no records exist of the number of cat shelters or their activities. The aim of this study was to investigate the occurrence of cat shelters in Sweden. We found 62 cat shelters during 2006; the year in which this study was conducted. Questionnaires were sent to these shelters with questions concerning: received animals, reasons for relinquishing cats, cat husbandry and how the shelter was run. The most common reason for relinquishing a cat was that the cat was homeless; another common reason was that the owner had an allergy to cats. The shelters had, on average, space for 29 cats, but this varied from six-to-100, and they received on average ten cats per month. This means that a total of around 7,400 cats enter the 62 shelters in Sweden each year. On average, the cats stayed more than three months in the shelter. Less than 10% of the relinquished cats were euthanised. Our study reveals that there are shelters that continuously receive unwanted cats. The majority of these cats are said to be homeless, therefore in order to minimise the number of cats in shelters in Sweden, the focus should be on reducing the number of homeless cats.

In this reply, we reiterate the main point of our 2012 paper, which was that the measure of inequality used by Norton and Ariely (2011) was too difficult for it to yield meaningful results. We describe additional evidence for this conclusion, and we also challenge the conclusion that political differences in perceived and desired inequality are small.

Experiments on economic games typically fail to find positive reputational effects of using peer punishment of selfish behavior in social dilemmas. Theorists had expected positive reputational effects because of the potentially beneficial consequences that punishment may have on norm violators’ behavior. Going beyond the game-theoretic paradigm, we used vignettes to study how various social factors influence approval ratings of a peer who reprimands a violator of a group-beneficial norm. We found that ratings declined when punishers showed anger, and this effect was mediated by perceived aggressiveness. Thus the same emotions that motivate peer punishers may make them come across as aggressive, to the detriment of their reputation. However, the negative effect of showing anger disappeared when the norm violation was sufficiently severe. Ratings of punishers were also influenced by social distance, such that it is less appropriate for a stranger than a friend to reprimand a violator. In sum, peer punisher ratings were very high for a friend reprimanding a severe norm violation, but particularly poor for a stranger showing anger at a mild norm violation. We found no effect on ratings of whether the reprimand had the beneficial consequence of changing the violator’s behavior. Our findings provide insight into how peer punishers can avoid negative reputational effects. They also point to the importance of going beyond economic games when studying peer punishment.

Biases in people’s judgments of time saved by increasing the speed of an activity have been studied mainly with hypothetical scenarios (Svenson, 2008). The present study asked whether the classic time-saving bias persists as a perceptual bias when we control the speed of an activity and assess the perceived time elapsed at different speeds. Specifically, we investigated the time-saving bias in a driving simulator. Each participant was asked to first drive a distance at a given speed and then drive the same distance again at the speed she or he judged necessary to gain exactly three minutes in travel time compared to the first trip. We found that that the time-saving bias applies to active driving and that it affects the choice of driving speed. The drivers’ time-saving judgements show that the perception of the time elapsed while driving does not eliminate the time-saving bias.

In markets with asymmetric information, only sellers have knowledge about the quality of goods. Sellers may of course make a declaration of the quality, but unless there are sanctions imposed on false declarations or reputations are at stake, such declarations are tantamount to cheap talk. Nonetheless, in an experimental study we find that most people make honest declarations, which is in line with recent findings that lies damaging another party are costly in terms of the liar's utility. Moreover, we find in this experimental market that deceptive sellers offer lower prices than honest sellers, which could possibly be explained by the same wish to limit the damage to the other party. However, when the recipient of the offer is a social tie we find no evidence for lower prices of deceptive offers, which seems to indicate that the rationale for the lower price in deceptive offers to strangers is in fact profit-seeking (by making the deal more attractive) rather than moral.

It is known that presentation of a meaningful label (e.g., "The Teamwork Game") can influence decisions in economic games. A common view is that such labels cue associations to preexisting mental models of situations, a process here called frame selection. In the absence of such cues, participants may still spontaneously associate a game with a preexisting frame. We used the public goods game to compare the effect of such spontaneous frame selection with the effect of label framing. Participants in a condition where the public goods game was labeled "The Teamwork Game" tended to contribute at the same level as participants who spontaneously associated the unlabeled game with teamwork, whereas those who did not associate the the unlabeled game with teamwork tended to make lower contributions. We conclude that neutrally described games may be subject to spontaneous frame selection effects comparable in size to the effects of label framing.

A strategy activated in one task may be transferred to subsequent tasks and prevent activation of other strategies that would otherwise come to mind, a mechanism referred to as procedural priming. In a novel application of procedural priming we show that it can make or break cognitive illusions. Our test case is the 1/k illusion, which is based on the same unwarranted mathematical shortcut as the MPG illusion and the time-saving bias. The task is to estimate distances between values of fractions on the form 1/k. Most people given this task intuitively base their estimates on the distances between the denominators (i.e., the reciprocals of the fractions), which may yield very poor estimations of the true distances between the fractions. As expected, the tendency to fall for this illusion is related to cognitive style (Study 1). In order to apply procedural priming we constructed versions of the task in which the illusion is weak, in the sense that most people do not fall for it anymore. We then gave participants both “strong illusion” and “weak illusion” versions of the task (Studies 2 and 3). Participants who first did the task in the weak illusion version would often persist with the correct strategy even in the strong illusion version, thus breaking the otherwise strong illusion in the latter task. Conversely, participants who took the strong illusion version first would then often fall for the illusion even in the weak illusion version, thus strengthening the otherwise weak illusion in the latter task.