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Two-sided matching is an important research area that has had a major impact on the design of real-world matching markets. One consistent feature in many of the real-world applications is that they impose new feasibility constraints that lead to research challenges. We survey developments in the field of two-sided matching with various constraints, including those based on regions, diversity, multi-dimensional capacities, and matroids.

Admission to universities is organised in a centralised scheme in Hungary. In this paper we investigate two major specialities of this application: ties and common quotas. A tie occur when some students have the same score at a programme. If not enough seats are available for the last tied group of applicants at a programme then there are three reasonable policies used in practice: 1) all must be rejected, as in Hungary 2) all can be accepted, as in Chile 3) a lottery decides which students are accepted from this group, as in Ireland. Even though student-optimal stable matchings can be computed efficiently for each of the above three cases, we developed (mixed) integer programming (IP) formulations for solving these problems, and compared the solutions obtained by the three policies for a real instance of the Hungarian application from 2008. In the case of Hungary common quotas arise from the faculty quotas imposed on their programmes and from the national quotas set for state-financed students in each subject. The overlapping structure of common quotas makes the computational problem of finding a stable solution NP-hard, even for strict rankings. In the case of ties and common quotas we propose two reasonable stable solution concepts for the Hungarian and Chilean policies. We developed (mixed) IP formulations for solving these stable matching problems and tested their performance on the large scale real instance from 2008 and also for one from 2009 under two different assumptions. We demonstrate that the most general case is also solvable in practice by IP technique.

Photonic nanoarchitectures of butterfly wings can serve as biotemplates to prepare semiconductor thin films of ZnO by atomic layer deposition. The resulting biotemplated ZnO nanoarchitecture preserves the structural and optical properties of the natural system, while it will also have the features of the functional material. The ZnO-coated wings can be used directly in heterogeneous photocatalysis to decompose pollutants dissolved in water upon visible light illumination. We used the photonic nanoarchitectures of different Morpho butterflies with different structural colors as biotemplates and examined the dependence of decomposition rates of methyl orange and rhodamine B dyes on the structural color of the biotemplates and the thickness of the ZnO coating. Using methyl orange, we measured a ten-fold increase in photodegradation rate when the 20 nm ZnO-coated wings were compared to similarly coated glass substrates. Using rhodamine B, a saturating relationship was found between the degradation rate and the thickness of the deposited ZnO on butterfly wings. We concluded that the enhancement of the catalytic efficiency can be attributed to the slow light effect due to a spectral overlap between the ZnO-coated Morpho butterfly wings reflectance with the absorption band of dyes, thus the photocatalytic performance could be changed by the tuning of the structural color of the butterfly biotemplates. The photodegradation mechanism of the dyes was investigated by liquid chromatography–mass spectroscopy.

The iridescent structural colours of butterflies, generated by photonic nanoarchitectures, often function as species-specific sexual signals; therefore, they are reproduced precisely from generation to generation. The wing scales of oakblue hairstreak butterflies (genus Arhopala , Theclinae, Lycaenidae, Lepidoptera) contain multi-layer photonic nanoarchitectures, which can generate a wide range of structural colours, from violet to green. By scanning (SEM) and cross-sectional transmission electron microscopy (TEM) investigation, the colour tuning mechanism of the cover scales was explored. We revealed that the characteristic size change of structural elements in similar photonic nanoarchitectures led to different structural colours that were examined by various reflectance spectrophotometry techniques. The measured structural properties of the naturally tuned photonic nanoarchitectures were used to calculate wing reflectances, which were compared with the measurement results. We found that the simulated structural colours were systematically redshifted by 95–126 nm as compared with the measured normal-incidence reflectance results. This is attributed to the swelling of the chitinous multi-layer structures during the standard TEM sample preparation and the tilt of the cover scales, which both affect the apparent layer thicknesses in the TEM cross-sections. We proposed a simulation correction and compared the results with the layer thicknesses measured on cryogenically prepared non-embedded SEM cross-sections.

The nymphalid butterfly Euphaedra neophron (Hopffer, 1855) is the only structurally coloured species representing the genus along the Indian Ocean coast in East Africa and Southern Africa, with a distribution from southern Somalia to the Kwa-Zulu-Natal region of South Africa. The range of E. neophron is subdivided to several, geographically distinct populations, currently recognised as subspecies by taxonomists on the basis of violet, blue, and green-coloured morphs. We investigated the optical mechanism of all these morphs by various materials science techniques. We found that the structural colour is generated by the lower lamina of the cover scales and the different colours are tuned according to their thickness, which was also proved by modelling. The colour tuning of the different subspecies does not reflect any clinal pattern, be it geographical or altitudinal.

We introduce a new two-sided stable matching problem that describes the summer internship matching practice of an Australian university. The model is a case between two models of Kamada and Kojima on matchings with distributional constraints. We study three solution concepts, the strong and weak stability concepts proposed by Kamada and Kojima, and a new one in between the two, called cutoff stability. Kamada and Kojima showed that a strongly stable matching may not exist in their most restricted model with disjoint regional quotas. Our first result is that checking its existence is NP-hard. We then show that a cutoff stable matching exists not just for the summer internship problem but also for the general matching model with arbitrary heredity constraints. We present an algorithm to compute a cutoff stable matching and show that it runs in polynomial time in our special case of summer internship model. However, we also show that finding a maximum size cutoff stable matching is NP-hard, but we provide a Mixed Integer Linear Program formulation for this optimisation problem., Extended version of our AAMAS 2020 paper "Summer Internship Matching with Funding Constraints"

Solar radiation is a cheap and abundant energy for water remediation, hydrogen generation by water splitting, and CO2 reduction. Supported photocatalysts have to be tuned to the pollutants to be eliminated. Spectral engineering may be a handy tool to increase the efficiency or the selectivity of these. Photonic nanoarchitectures of biological origin with hierarchical organization from nanometers to centimeters are candidates for such applications. We used the blue wing surface of laboratory-reared male Polyommatus icarus butterflies in combination with atomic layer deposition (ALD) of conformal ZnO coating and octahedral Cu2O nanoparticles (NP) to explore the possibilities of engineering the optical and catalytic properties of hybrid photonic nanoarchitectures. The samples were characterized by UV-Vis spectroscopy and optical and scanning electron microscopy. Their photocatalytic performance was benchmarked by comparing the initial decomposition rates of rhodamine B. Cu2O NPs alone or on the butterfly wings, covered by a 5 nm thick layer of ZnO, showed poor performance. Butterfly wings, or ZnO coated butterfly wings with 15 nm ALD layer showed a 3 to 3.5 times enhancement as compared to bare glass. The best performance of almost 4.3 times increase was obtained for the wings conformally coated with 15 nm ZnO, deposited with Cu2O NPs, followed by conformal coating with an additional 5 nm of ZnO by ALD. This enhanced efficiency is associated with slow light effects on the red edge of the reflectance maximum of the photonic nanoarchitectures and with enhanced carrier separation through the n-type ZnO and the p-type Cu2O heterojunction. Properly chosen biologic photonic nanoarchitectures in combination with carefully selected photocatalyst(s) can significantly increase the photodegradation of pollutants in water under visible light illumination.

We study generalized Shapley-Scarf exchange markets where each agent is endowed with multiple units of an indivisible and agent-specific good and monetary compensations are not possible. An outcome is given by a circulation which consists of a balanced exchange of goods. We focus on circulation rules that only require as input ordinal preference rankings of individual goods, and agents are assumed to have responsive preferences over bundles of goods. We study the properties of serial dictatorship rules which allow agents to choose either a single good or an entire bundle sequentially, according to a fixed ordering of the agents. We also introduce and explore extensions of these serial dictatorship rules that ensure individual rationality. The paper analyzes the normative and incentive properties of these four families of serial dictatorships and also shows that the individually rational extensions can be implemented with efficient graph algorithms., PBiró gratefully acknowledges the financial support by the Hungarian Academy of Sciences, Momentum Grant No. LP2021-2, and by the Hungarian Scientific Research Fund, OTKA, Grant No. K143858. F. Klijn gratefully acknowledges financial support from AGAUR–Generalitat de Catalunya (2017-SGR-1359) and the Spanish Agencia Estatal de Investigación (AEI) through grants ECO2017-88130-P and PID2020-114251GB-I00 (funded by MCIN/ AEI /10.13039/501100011033) and the Severo Ochoa Programme for Centres of Excellence in R&D (Barcelona School of Economics, SEV-2015-0563 and CEX2019-000915-S). S. Pápai gratefully acknowledges financial support from an FRQSC grant titled “Formation des coalitions et des réseaux dans les situations économiques et sociales avec des externalités” (SE-144698)

We allocate objects to agents as exemplified primarily by school choice. Welfare judgments of the object-allocating agency are encoded as edge weights in the acceptability graph. The welfare of an allocation is the sum of its edge weights. We introduce the constrained welfare-maximizing solution, which is the allocation of highest welfare among the Pareto-efficient allocations. We identify conditions under which this solution is easily determined from a computational point of view. For the unrestricted case, we formulate an integer program and find this to be viable in practice as it quickly solves a real-world instance of kindergarten allocation and large-scale simulated instances. Incentives to report preferences truthfully are discussed briefly.

Porous butterfly wings with hierarchically organized structures from nanometer to centimeter scales were tested as substrates for carrying plasmonic Au and Ag/Au nanoparticles with potential application in photocatalysis. Wings exhibiting structural color generated by chitin-air nanocomposites were used. Hundreds of butterfly species possess these types of color-generating photonic nanoarchitectures, producing color by a similar mechanism to manmade photonic crystals. Artificial photonic crystals are known to enhance photocatalytic processes through the slow light effect. The impact of pure water, water-based sodium citrate solution, and Au and Ag/Au alloy nanoparticles on the optical properties of the natural photonic structures were separated. While water and aqueous sodium citrate solutions change the wing reflectance by the alteration of the wing scale position with respect to the wing plane, Au and Ag/Au alloy nanoparticles form a new, hybrid nanostructure with the chitin nanoarchitecture modifying the structural color of the butterfly wings. The optical properties of the new types of hybrid photonic nanoarchitectures (consisting of butterfly wings and plasmonic nanoparticles) are different from those of the components.

The photocatalytic activity of a flat surface can be increased by micro- and nanostructuring the interface to increase the area of the contact surface between the photocatalyst and the solute, and moreover, to optimize charge carrier transfer. Further enhancement can be achieved by using photonic nanostructures, which exhibit photonic band gap (PBG). Structurally coloured butterfly wings offer a rich ‘library’ of PBGs in the visible spectral range which can be used as naturally tuned sample sets for biotemplating. We used conformal atomic layer deposition of ZnO on the wings of various butterfly species ( Arhopala asopia , Hypochrysops polycletus , Morpho sulkowskyi , Polyommatus icarus ) possessing structural colour extending from the near UV to the blue wavelength range, to test the effects arising from the nanostructured surfaces and from the presence of different types of PBGs. Aqueous solutions of rhodamine B were used to test the enhancement of photocatalytic activity that was found for all ZnO-coated butterfly wings. The best reaction rate of decomposing rhodamine B when illuminated with visible light was found in 15 nm ZnO coated M. sulkowskyi wing, the reflectance of which had the highest overlap with the absorption band of the dye and had the highest reflectance intensity.

Behavioral and physiological ecologists have long been interested in explaining the causes and consequences of trait variation, with a focus on individual differences in mean values. However, the majority of phenotypic variation typically occurs within individuals, rather than among individuals (as indicated by average repeatability being less than 0.5). Recent studies have further shown that individuals can also differ in the magnitude of variation that is unexplained by individual variation or environmental factors (i.e., residual variation). The significance of residual variation, or why individuals differ, is largely unexplained, but is important from evolutionary, methodological, and statistical perspectives. Here, we broadly reviewed literature on individual variation in behavior and physiology, and located 39 datasets with sufficient repeated measures to evaluate individual differences in residual variance. We then analyzed these datasets using methods that permit direct comparisons of parameters across studies. This revealed substantial and widespread individual differences in residual variance. The magnitude of individual variation appeared larger in behavioral traits than in physiological traits, and heterogeneity was greater in more controlled situations. We discuss potential ecological and evolutionary implications of individual differences in residual variance and suggest productive future research directions., Animals are typically quite unpredictable in behavior with the majority of variance unexplained. We returned to raw data of previously published work, and found almost ubiquitously that individuals vary in their predictability. We discuss potential ecological and evolutionary implications of individual differences in residual variance and suggest productive future research directions.

Robins in the family Petroicidae are characteristic of the woodland bird community that is threatened in Australia as a result of habitat loss and fragmentation. Flame Robin (Petroica phoenicea) populations declined by 56% between 1980 and 2000, with habitat loss likely being the primary cause. Given that Flame Robins primarily breed at high elevation, populations may become more isolated due to anthropogenic change, resulting in increased inbreeding and loss of genetic diversity that may accelerate local extinction. We estimated the genetic structure and recent gene flow among four populations (n = 70 birds) of this vulnerable (NSWSC) species across a 670 km portion of its range in temperate south-eastern Australia using 14 genetic markers. We found no significant differences in genetic diversity amongst populations and little population structuring – only the northernmost population showing a weak signal of differentiation. However, we detected little recent migration between the northern and southern sites, possibly due to recent fragmentation. We conclude that habitat loss is a conservation concern for this Vulnerable species and further work and ongoing genetic monitoring is needed, particularly given high elevation breeding sites that are vulnerable in the face of a changing climate.

Jelen essze betekintest kivan nyujtani a nem szorosan ezzel foglalkozo olvaso szamara a 2020. evi kozgazdasagi Nobel-dijasok, Paul Robert Milgrom es Robert Butler Wilson szakteruletebe, az aukcioelmeletbe. Ahhoz, hogy megertsuk, milyen megfontolasokbol es milyen cellal kaptak a Nobel-dijat, erdemes egyet hatralepve, nagyobb tavolsagbol nezni a kozgazdasagtan e teruletere. Emiatt nem kifejezetten csak az ő nevukhoz kotődő eredmenyekről szamolunk itt be, hanem attekintjuk az ide vezető utat is. Vegul kitekintest adunk a temakor jovőjere nezve, a mernoki kozgazdasagtan es piactervezes interdiszciplinaris teruleteinek rovid ismertetesevel.

This paper seeks to provide insight into the field of auction theory to the general readership, the area of the 2020 Nobel laureates in Economic Sciences, Paul Milgrom and Robert Wilson. To understand for what reasons and for what purpose they were awarded the Nobel Prize, it is worth taking a step back, looking at this area of economics from a greater distance. For this reason, we not only report the results associated specifically with their names here, but we also review the path to get here. Finally, we provide an outlook for the future of the topic with a brief description of the interdisciplinary areas of engineering economics and market design.

In kidney exchange programmes patients with end-stage renal failure may exchange their willing, but incompatible living donors among each other. National kidney exchange programmes are in operation in ten European countries, and some of them have already conducted international exchanges through regulated collaborations. The exchanges are selected by conducting regular matching runs (typically every three months) according to well-defined constraints and optimisation criteria, which may differ across countries. In this work we give integer programming formulations for solving international kidney exchange problems, where the optimisation goals and constraints may be different in the participating countries and various feasibility criteria may apply for the international cycles and chains. We also conduct simulations showing the long-run effects of international collaborations for different pools and under various national restrictions and objectives. We compute the expected gains of the cooperation between two countries with different pool sizes and different restrictions on the cycle-length. For instance, if country A allows 3-way cycles and country B allows 2-way cycles only, whilst the pool size of country A is four times larger than the pool size of country B (which is a realistic case for the relation of Spain and France, respectively), then the increase in the number of transplants will be about 2% for country A and about 37% for country B.

International audience; Strong and ongoing artificial selection in domestic animals has resulted in amazing phenotypic responses that benefit humans, but often at a cost to an animal's health, and problems related to inbreeding depression, including a higher incidence of cancer. Despite high rates of cancer in domesticated species, little attention has been devoted to exploring the hypothesis that persistent artificial selection may also favour the evolution of compensatory anticancer defences. Indeed, there is evidence for effective anti‐cancer defences found in several domesticated species associated with different cancer types. We also suggest that artificial selection can favour the “domestication” of inherited oncogenic mutations in rare instances, retaining those associated to late and/or less aggressive cancers, and that by studying these seemingly rare anticancer adaptations, novel cancer treatments may be found.

Attempts to unravel the proximate and ultimate causes of individual behavioural and life history variation have often pointed to predicted correlations between behavioural, physiological and life history traits, forming pace-of-life syndromes (POLS). The POLS hypothesis predicts that high levels of production (growth, fecundity) require high levels of foraging effort and risk taking, supported by high metabolism. Despite tremendous interest in this topic, the POLS hypothesis still has limited empirical support, which has led to calls for more stringent empirical tests of the hypothesis and its assumptions. To that end, we examined the associations between risk-taking behaviour (boldness), resting metabolic rate (RMR) and somatic growth rate in a marine gastropod, Littoraria irrorata, under controlled laboratory conditions using a longitudinal repeated measures design. After accounting for the effects of sex, size and time (trial number), a multivariate mixed model revealed that bolder individuals had higher RMR, and grew faster, whereas RMR and growth were not strongly correlated. Further, if individuals were bolder than their average on a given day, then their RMR was also higher. Our study represents rare and compelling support for the POLS hypothesis, simultaneously studying its three key components (behaviour, energetics and life history), the success of which we attribute to careful control, concurrent sampling of each trait, and rigorous analysis of the among- and within-individual patterns of variation and covariance.

In this essay, composer Dániel Péter Biró reveals his methodology and trajectory as a professor of music composition in the last 16 years. Biró explains how can one teaches a creative artistic process nowadays, in a globalized musical culture, which is full of possibilities for development of cultural diversity while simultaneously providing students distractions driven by capitalist paradigms. How can one help each student to develop his/her own musical language? For this task, Biró talks about how composition today is creative process highly grounded in intellectual and interdisciplinary approaches, sharing similarities with other areas of research such as philosophy and history. For this task, the composer relies on musical analysis in his seminars and individual lessons as one of the strongest methodologies to learn composition, alongside integrating music technology and contemporary performance practice research. [note by editor].