The implications of unconfounding multisource performance ratings.

The multifaceted structure of multisource job performance ratings has been a subject of research and debate for over 30 years. However, progress in the field has been hampered by the confounding of effects relevant to the measurement design of multisource ratings and, as a consequence, the impact of ratee-, rater-, source-, and dimension-related effects on the reliability of multisource ratings remains unclear. In separate samples obtained from 2 different applications and measurement designs (N1 [ratees] = 392, N1 [raters] = 1,495; N2 [ratees] = 342, N2 [raters] = 2,636), we, for the first time, unconfounded all systematic effects commonly cited as being relevant to multisource ratings using a Bayesian generalizability theory approach. Our results suggest that the main contributors to the reliability of multisource ratings are source-related and general performance effects that are independent of dimension-related effects. In light of our findings, we discuss the interpretation and application of multisource ratings in organizational contexts. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Common guillemot (Uria aalge) eggs are not self-cleaning.

Birds are arguably the most evolutionarily successful extant vertebrate taxon, in part because of their ability to reproduce in virtually all terrestrial habitats. Common guillemots, Uria aalge, incubate their single egg in an unusual and harsh environment; on exposed cliff ledges, without a nest, and in close proximity to conspecifics. As a consequence, the surface of guillemot eggshells is frequently contaminated with faeces, dirt, water and other detritus, which may impede gas exchange or facilitate microbial infection of the developing embryo. Despite this, guillemot chicks survive incubation and hatch from eggs heavily covered with debris. To establish how guillemot eggs cope with external debris, we tested three hypotheses: (1) contamination by debris does not reduce gas exchange efficacy of the eggshell to a degree that may impede normal embryo development; (2) the guillemot eggshell surface is self-cleaning; (3) shell accessory material (SAM) prevents debris from blocking pores, allowing relatively unrestricted gas diffusion across the eggshell. We showed that natural debris reduces the conductance of gases across the guillemot eggshell by blocking gas exchange pores. Despite this problem, we found no evidence that guillemot eggshells are self-cleaning, but instead showed that the presence of SAM on the eggshell surface largely prevents pore blockages from occurring. Our results demonstrate that SAM is a crucial feature of the eggshell surface in a species with eggs that are frequently in contact with debris, acting to minimise pore blockages and thus ensure a sufficient rate of gas diffusion for embryo development.

Everything that you have ever been told about assessment center ratings is confounded.

Despite a substantial research literature on the influence of dimensions and exercises in assessment centers (ACs), the relative impact of these 2 sources of variance continues to raise uncertainties because of confounding. With confounded effects, it is not possible to establish the degree to which any 1 effect, including those related to exercises and dimensions, influences AC ratings. In the current study (N = 698) we used Bayesian generalizability theory to unconfound all of the possible effects contributing to variance in AC ratings. Our results show that ≤1.11% of the variance in AC ratings was directly attributable to behavioral dimensions, suggesting that dimension-related effects have no practical impact on the reliability of ACs. Even when taking aggregation level into consideration, effects related to general performance and exercises accounted for almost all of the reliable variance in AC ratings. The implications of these findings for recent dimension- and exercise-based perspectives on ACs are discussed. (PsycINFO Database Record

Weak patriline effects are present in the cuticular hydrocarbon profiles of isolated Formica exsecta ants but they disappear in the colony environment.

Chemical recognition cues are used to discriminate among species, con-specifics, and potentially between patrilines in social insect colonies. There is an ongoing debate about the possible persistence of patriline cues despite evidence for the mixing of colony odors via a "gestalt" mechanism in social insects, because patriline recognition could lead to nepotism. We analyzed the variation in recognition cues (cuticular hydrocarbons) with different mating frequencies or queen numbers in 688 Formica exsecta ants from 76 colonies. We found no increase in the profile variance as genetic diversity increased, indicating that patriline effects were absent or possibly obscured by a gestalt mechanism. We then demonstrated that an isolated individual's profile changed considerably relative to their colony profile, before stabilizing after 5 days. We used these isolated individuals to eliminate the masking effects of the gestalt mechanism, and we detected a weak but statistically significant patriline effect in isolated adult workers and also in newly emerged callow workers. Thus, our evidence suggests that genetic variation in the cuticular hydrocarbon profile of F. exsecta ants (n-alkanes and alkenes) resulted in differences among patrilines, but they were obscured in the colony environment, thereby avoiding costly nepotistic behaviors.

Trends in telemedicine assessment indicate neglect of key criteria for predicting success.

PURPOSE: This innovative analysis aims to quantify the use of evaluation criteria in telemedicine and to identify current trends in metric adoption. The focus is to determine the frequency of actual performance metric reporting in telemedicine evaluation, in contrast to systematic reviews where assessment of study quality is the goal. DESIGN/METHODOLOGY/APPROACH: Automated literature search identified telemedicine studies reporting quantitative performance metrics. Studies were classified by telemedicine class; store-and-forward (SAF), real-time consultation (RTC) and telecare (TC), and study stage. Studies were scanned for evaluation metric reporting, i.e. clinical outcomes, satisfaction, patient quality and cost measures. FINDINGS: Evaluation metric use was compared among telemedicine classes, and between pilot and routine use stages. Diagnostic accuracy was reported significantly more frequently in pilots for RTC and TC. Cost measures were more frequently reported in routine use for TC. Clinical effectiveness and hospital attendance were better reported in routine use for SAF. Comparison also revealed different evaluation strategies. In pilots, SAF favoured diagnostic accuracy, compared to RTC and TC. TC preferred clinical effectiveness evaluations and TC more frequently assessed patient satisfaction. Cost was only reported in less than 20 per cent of studies, but most frequently in RTC. Routine use led to increased reporting of all metrics, except diagnostic accuracy. Clinical effectiveness reporting increased significantly with routine use for RTC and SAF, but declined for TC. ORIGINALITY/VALUE: Clinical outcomes and patient satisfaction were reported frequently in telemedicine studies, but reporting of other performance metrics was rare. Understanding current trends in metric reporting will facilitate better design of future telemedicine evaluations.

Conspecific ant aggression is correlated with chemical distance, but not with genetic or spatial distance.

Five possible mechanisms might underlie kin recognition in social groups: spatial location, familiarity through prior association, phenotype matching, recognition alleles, or rejecting unfamiliar cues. Kin recognition by phenotype matching relies on a strong correlation between genotype and phenotype. Aggression bioassays are the standard method for investigating recognition in animals, particularly social insect interactions among nestmates and non-nestmates. These bioassays typically pay little regard to how outcomes are determined by differences in chemical recognition cues of the test subjects, because the system of signal coding was unknown until recently. We exploited the known nestmate recognition system of the ant Formica exsecta to investigate aggression between 24 pairs of colonies across a range of chemical (Z9-alkene & n-alkanes), genetic, and spatial distances. The whole Z9-alkene chemical profile was the only significant (p < 0.001) predictor of aggression levels. Aggression was a nonlinear step function of Z9-alkene chemical distance, where a small change in chemical profile resulted in a rapid behavioural transition from non-aggression to overt aggression. These findings raise questions surrounding our current understanding of recognition systems, because they support phenotype matching to a colony chemical profile without a significant genetic or spatial component.

Modelling complex biological systems using an agent-based approach.

Many of the complex systems found in biology are comprised of numerous components, where interactions between individual agents result in the emergence of structures and function, typically in a highly dynamic manner. Often these entities have limited lifetimes but their interactions both with each other and their environment can have profound biological consequences. We will demonstrate how modelling these entities, and their interactions, can lead to a new approach to experimental biology bringing new insights and a deeper understanding of biological systems.

Sex allocation: size matters for red spider mites.

Many animals can adjust the sex ratio of their offspring according to their parental ability to invest. In spider mites, larger eggs are likely to be fertilized and produce diploid females, whereas smaller eggs produce haploid males.

Nutritional ecology: a first vegetarian spider.

Mutualisms are ubiquitous in nature and equally commonplace is their exploitation. A well-known mutualism has been found to be exploited from a surprising source: the first described vegetarian spider dines on trophic structures produced by acacia trees to reward their mutualistic protective ants.

Sympatric speciation: perfume preferences of orchid bee lineages.

Female attraction to an environmentally derived mating signal released by male orchid bees may be tightly linked to shared olfactory preferences of both sexes. A change in perfume preference may have led to divergence of two morphologically distinct lineages.

Interspecific communication: treehopper alarms make ants come running.

Stable mutualisms are ubiquitous in nature and this presents a puzzle for evolutionary biology. A new study of interactions between treehoppers and ants shows that honest communication coordinates anti-predator behaviour to improve the efficiency of the service ants provide.

Chemical coevolution: host-parasite arms race runs hot and cold.

Coevolution is a major process operating across biological communities at a range of spatial scales. Rapid ecological change makes it vital that we understand how coevolution proceeds if we are to conserve genetic diversity, combat disease and predict the effects of species invasions.

Social evolution: pathways to ant unicoloniality.

Unicolonial ant species live in interlinked populations known as super-colonies, where workers and queens move freely. New research suggests that low intra-specific resource competition leads to an absence of inter-colony aggression.

Kin recognition: knowing who's boss in wasp colonies.

Paper wasps recognise the dominant individual in their colony and surrender reproduction to this alpha individual. Contrary to expectations her dominance status is not signalled by a chemical indicator of fertility.

Insect communication: 'no entry' signal in ant foraging.

Forager ants lay attractive trail pheromones to guide nestmates to food, but the effectiveness of foraging networks might be improved if pheromones could also be used to repel foragers from unrewarding routes. Here we present empirical evidence for such a negative trail pheromone, deployed by Pharaoh's ants (Monomorium pharaonis) as a 'no entry' signal to mark an unrewarding foraging path. This finding constitutes another example of the sophisticated control mechanisms used in self-organized ant colonies.

Trail geometry gives polarity to ant foraging networks.

Pheromone trails are used by many ants to guide foragers between nest and food. But how does a forager that has become displaced from a trail know which way to go on rejoining the trail? A laden forager, for example, should walk towards the nest. Polarized trails would enable ants to choose the appropriate direction, thereby saving time and reducing predation risk. However, previous research has found no evidence that ants can detect polarity from the pheromone trail alone. Pharaoh's ants (Monomorium pharaonis) produce elaborate trail networks throughout their foraging environment. Here we show that by using information from the geometry of trail bifurcations within this network, foragers joining a trail can adaptively reorientate themselves if they initially walk in the wrong direction. The frequency of correct reorientations is maximized when the trail bifurcation angle is approximately 60 degrees, as found in natural networks. These are the first data to demonstrate how ant trails can themselves provide polarity information. They also demonstrate previously unsuspected sophistication in the organization and information content of networks in insect societies.

Coupled computational simulation and empirical research into the foraging system of Pharaoh's ant (Monomorium pharaonis).

The Pharaoh's ant (Monomorium pharaonis), a significant pest in many human environments, is phenomenally successful at locating and exploiting available food resources. Several pheromones are utilized in the self-organized foraging of this ant but most aspects of the overall system are poorly characterised. Agent-based modelling of ants as individual complex X-machines facilitates study of the mechanisms underlying the emergence of trails and aids understanding of the process. Conducting simultaneous modelling, and simulation, alongside empirical biological studies is shown to drive the research by formulating hypotheses that must be tested before the model can be verified and extended. Integration of newly characterised behavioural processes into the overall model will enable testing of general theories giving insight into division of labour within insect societies. This study aims to establish a new paradigm in computational modelling applicable to all types of multi-agent biological systems, from tissues to animal societies, as a powerful tool to accelerate basic research.