A kin-selection model of fairness in heterogeneous populations

Humans and other primates exhibit pro-social preferences for fairness. These preferences are thought to be reinforced by strong reciprocity, a policy that rewards fair actors and punishes unfair ones. Theories of fairness based on strong reciprocity have been criticized for overlooking the importance of individual differences in socially heterogeneous populations. Here, we explore the evolution of fairness in a heterogeneous population. We analyse the Ultimatum Game in cases where players’ roles in the game are determined by their status. Importantly, our model allows for non-random pairing of players, and so we also explore the role played by kin selection in shaping fairness. Our kin-selection model shows that, when individuals condition their behaviour on their role in the game, fairness can be understood as either altruistic or spiteful. Altruistic fairness directs resources from less valuable members of a genetic lineage to more valuable members of the same lineage, whereas spiteful fairness keeps resources away from the competitors of the actor’s high-value relatives. When individuals express fairness unconditionally it can be understood as altruistic or selfish. When it is altruistic, unconditional fairness again serves to direct resources to high-value members of genetic lineages. When it is selfish, unconditional fairness simply improves an individual’s own standing. Overall, we expand kin-selection based explanations for fairness to include motivations other than spite. We show, therefore, that one need not invoke strong reciprocity to explain the advantage of fairness in heterogeneous populations

Trapped-ion quantum error-correcting protocols using only global operations

Quantum error-correcting codes are many-body entangled states that are prepared and measured using complex sequences of entangling operations. Each element of such an entangling sequence introduces noise to delicate quantum information during the encoding or reading out of the code. It is important therefore to find efficient entangling protocols to avoid the loss of information. Here we propose an experiment that uses only global entangling operations to encode an arbitrary logical qubit to either the five-qubit repetition code or the five-qubit code, with a six-ion Coulomb crystal architecture in a Penning trap. We show that the use of global operations enables us to prepare and read out these codes using only six and ten global entangling pulses, respectively. The proposed experiment also allows the acquisition of syndrome information during readout. We provide a noise analysis for the presented protocols, estimating that we can achieve a six-fold improvement in coherence time with noise as high as $\sim 1\%$ on each entangling operation.Comment: 7 pages, 4 figures, published version, comments are welcom

Cold tolerance of the eastern subterranean termite, Reticulitermes flavipes (Isoptera: Rhinotermitidae), in Ontario.

We characterized the cold tolerance of natural populations of the Eastern subterranean termite (Reticulitermes flavipes (Kollar) [Isoptera, Rhinotermitidae]) in southwestern Ontario, Canada. We measured cold tolerance in workers from six colonies of termites established from Pelee Island in Lake Erie, and Point Pelee National Park. The mean critical thermal minimum, at which termites entered chill coma, ranged from 8.1 to 5.7°C. Mean supercooling points (SCP, the temperature at which individuals freeze) ranged from -4 to -4.6°C, and did not differ significantly between colonies, nor was SCP dependent on body size. Individuals survived brief exposure to low temperatures, as long as they did not freeze, but internal ice formation was always lethal, suggesting a freeze avoiding strategy. The LT50 (temperature at which 50% of individuals were killed by a 1 h exposure) was -5.1°C, but all individuals could survive -2°C for at least 72 h. Low temperature acclimation (12°C, 7 d) or hardening (4°C, 2 h) had no impact on the SCP, but acclimation did slightly increase the critical thermal minimum, making the termites less cold tolerant. We conclude that R. flavipes is not particularly cold tolerant, and likely relies on burrowing deep into the soil to avoid exposure to temperature to extremes

Optimal body size with respect to maximal speed for the yellow-spotted monitor lizard (Varanus panoptes; varanidae)

Studies of locomotor performance often link variation in morphology with ecology. While maximum sprint speed is a commonly used performance variable, the absolute limits for this performance trait are not completely understood. Absolute maximal speed has often been shown to increase linearly with body size, but several comparative studies covering a large range of body sizes suggest that maximal speed does not increase indefinitely with body mass but rather reaches an optimum after which speed declines. Because of the comparative nature of these studies, it is difficult to determine whether this decrease is due to biomechanical constraints on maximal speed or is a consequence of phylogenetic inertia or perhaps relaxed selection for lower maximal speed at large body size. To explore this issue, we have examined intraspecific variations in morphology, maximal sprint speed, and kinematics for the yellowspotted monitor lizard Varanus panoptes, which varied in body mass from 0.09 to 5.75 kg. We show a curvilinear relationship between body size and absolute maximal sprint speed with an optimal body mass with respect to speed of 1.245 kg. This excludes the phylogenetic inertia hypothesis, because this effect should be absent intraspecifically, while supporting the biomechanical constraints hypothesis. The relaxed selection hypothesis cannot be excluded if there is a size-based behavioral shift intraspecifically, but the biomechanical constraints hypothesis is better supported from kinematic analyses. Kinematic measurements of hind limb movement suggest that the distance moved by the body during the stance phase may limit maximum speed. This limit is thought to be imposed by a decreased ability of the bones and muscles to support body mass for larger lizards

Sampling of aryldiazonium, anilino, and aryl radicals by membrane introduction mass spectrometry: Thermolysis of aromatic diazoamino compounds

Membrane introduction mass spectrometry (MIMS) is used to sample free radicals generated by thermolysis at atmospheric pressure. This is done by heating the solid sample in a custom-made probe that is fitted with a silicone membrane to allow selective and rapid introduction of the pyrolysates into the ion source of a triple quadrupole mass spectrometer. Phenyldiazonium radical (C6H5N2) and some of its ring-substituted analogs, the methoxy anilino radical CH3OC6H4NH, and aryl radicals are generated by gas phase thermolysis of symmetrical aryl diazoamino compounds (ArNH-N2Ar). The radicals are identified by measurement of their ionization energies (IE) using threshold ionization efficiency data. A linear correlation between the ionization energy of the phenyldiazonium radicals and their Brown σ+ values is observed, and this confirms the formation of these species and validates the applicability of MIMS in sampling these radicals. The ionization energies of the aryldiazonium radicals are estimated as IE (p-CH3O-C6H4N2·), 6.74 ± 0.2 eV; IE (p-CH3-C6H4N2·), 7.72 ± 0.2 eV; IE (C6H5N2·), 7.89 ± 0.2 eV; IE (m-Cl-C6H4N2·), 7.91 ± 0.2 eV; IE (p-F-C6H4N2·), 8.03 ± 0.2 eV; and IE (m-NO2-C6H4N2·), 8.90 = 0.2 eV. The ionization energies of the aryl radicals are estimated as IE (p-CH3O-C6H4·), 7.33 ± 0.2 eV; IE (p-CH3-C6H4·), 8.31 ± 0.2 eV; IE (C6H5·), 8.44 ± 0.2 eV; IE (m-Cl-C6H4·), 8.50 ± 0.2 eV and IE (p-F-C6H4), 8.54 ± 0.2 eV. Also, the ionization energy of the p-methoxyanilino radical (p-CH3O-C6H4NH·) is estimated as 7.63 ± 0.2 eV

Operational reliability assessment of the GEOS A spacecraft

Decision theory application to GEOS A spacecraft operational reliability assessmen

Rotational Grazing Increases Wool and Lamb Production from Phalaris-Subterranean Clover Pastures in South Eastern Australia

Wool and lamb production from different grazing systems was compared in a Mediterranean environment near Hamilton in southeastern Australia. The grazing systems were based on combinations of fertiliser inputs and grazing methods that could promote the growth and persistence of phalaris (Phalaris aquatica) and increase animal production compared to ‘typical’ unimproved pastures. In the first 2 years of this experiment, the most productive systems more than doubled ewe stocking rate and wool production, and more than trebled lamb production per hectare, compared to ‘typical’ unimproved pasture, low fertility, set-stocked systems. The change to a well fertilised phalaris/subterranean clover (Trifolium subterraneum) pasture system accounted for 50-80% of these gains in productivity per hectare, with additional benefits from applying extra phosphorus (P) fertiliser and rotational grazing. These results show the potential for producers to adopt simple changes in management practices that can significantly increase wool and lamb production in southeastern Australia

Conceptualisations of children’s wellbeing at school: the contribution of recognition theory

A large study in Australian schools aimed to elucidate understandings of ‘wellbeing’ and of factors in school life that contribute to it. Students and teachers understood wellbeing primarily, and holistically, in terms of interpersonal relationships, in contrast to policy documents which mainly focused on ‘problem areas’ such as mental health. The study also drew on recognition theory as developed by the social philosopher Axel Honneth. Results indicate that recognition theory may be useful in understanding wellbeing in schools, and that empirical research in schools may give rise to further questions regarding theory

Active Temporal Multiplexing of Photons

Photonic qubits constitute a leading platform to disruptive quantum technologies due to their unique low-noise properties. The cost of the photonic approach is the non-deterministic nature of many of the processes, including single-photon generation, which arises from parametric sources and negligible interaction between photons. Active temporal multiplexing - repeating a generation process in time and rerouting to single modes using an optical switching network - is a promising approach to overcome this challenge and will likely be essential for large-scale applications with greatly reduced resource complexity and system sizes. Requirements include the precise synchronization of a system of low-loss switches, delay lines, fast photon detectors, and feed-forward. Here we demonstrate temporal multiplexing of 8 'bins' from a double-passed heralded photon source and observe an increase in the heralding and heralded photon rates. This system points the way to harnessing temporal multiplexing in quantum technologies, from single-photon sources to large-scale computation.Comment: Minor revision