Inferred Attractiveness: A generalized mechanism for sexual selection that can maintain variation in traits and preferences over time

Sexual selection by mate choice is a powerful force that can lead to evolutionary change, and models of why females choose particular mates are central to understanding its effects. Predominant mate choice theories assume preferences are determined solely by genetic inheritance, an assumption still lacking widespread support. Moreover, preferences often vary among individuals or populations, fail to correspond with conspicuous male traits, or change with context, patterns not predicted by dominant models. Here, we propose a new model that explains this mate choice complexity with one general hypothesized mechanism, “Inferred Attractiveness.” In this model, females acquire mating preferences by observing others’ choices and use context-dependent information to infer which traits are attractive. They learn to prefer the feature of a chosen male that most distinguishes him from other available males. Over generations, this process produces repeated population-level switches in preference and maintains male trait variation. When viability selection is strong, Inferred Attractiveness produces population-wide adaptive preferences superficially resembling “good genes.” However, it results in widespread preference variation or nonadaptive preferences under other predictable circumstances. By casting the female brain as the central selective agent, Inferred Attractiveness captures novel and dynamic aspects of sexual selection and reconciles inconsistencies between mate choice theory and observed behavior

The mediating effect of task presentation on collaboration and children's acquisition of scientific reasoning

There has been considerable research concerning peer interaction and the acquisition of children's scientific reasoning. This study investigated differences in collaborative activity between pairs of children working around a computer with pairs of children working with physical apparatus and related any differences to the development of children's scientific reasoning. Children aged between 9 and 10 years old (48 boys and 48 girls) were placed into either same ability or mixed ability pairs according to their individual, pre-test performance on a scientific reasoning task. These pairs then worked on either a computer version or a physical version of Inhelder and Piaget's (1958) chemical combination task. Type of presentation was found to mediate the nature and type of collaborative activity. The mixed-ability pairs working around the computer talked proportionally more about the task and management of the task; had proportionally more transactive discussions and used the record more productively than children working with the physical apparatus. Type of presentation was also found to mediated children's learning. Children in same ability pairs who worked with the physical apparatus improved significantly more than same ability pairs who worked around the computer. These findings were partially predicted from a socio-cultural theory and show the importance of tools for mediating collaborative activity and collaborative learning

Socioeconomic benefit to individuals of achieving 2020 targets for four neglected tropical diseases controlled/eliminated by innovative and intensified disease management

__Background__ The control or elimination of neglected tropical diseases (NTDs) has targets defined by the WHO for 2020, reinforced by the 2012 London Declaration. We estimated the economic impact to individuals of meeting these targets for human African trypanosomiasis, leprosy, visceral leishmaniasis and Chagas disease, NTDs controlled or eliminated by innovative and intensified disease management (IDM). __Methods__ A systematic literature review identified information on productivity loss and out-of-pocket payments (OPPs) related to these NTDs, which were combined with projections of the number of people suffering from each NTD, country and year for 2011±2020 and 2021±2030. The ideal scenario in which the WHO's 2020 targets are met was compared with a counterfactual scenario that assumed the situation of 1990 stayed unaltered. Economic benefit equaled the difference between the two scenarios. Values are reported in 2005 US, purchasing power parity-adjusted, discounted at 3% per annum from 2010. Probabilistic sensitivity analyses were used to quantify the degree of uncertainty around the base-case impact estimate. __Results__ The total global productivity gained for the four IDM-NTDs was I 23.1 (I$15.9 ±I$ 34.0) billion in 2011±2020 and I$35.9 (I$ 25.0 ±I$51.9) billion in 2021±2030 (2.5th and 97.5th percentiles in brackets), corresponding to US$ 10.7 billion (US$7.4 ±US$ 15.7) and US$16.6 billion (US$ 11.6 ±US$24.0). Reduction in OPPs was I$ 14 billion (US$6.7 billion) and I$ 18 billion (US$ 10.4 billion) for the same periods. __Conclusions__ We faced important limitations to our work, such as finding no OPPs for leprosy. We had to combine limited data from various sources, heterogeneous background, and of variable quality. Nevertheless, based on conservative assumptions and subsequent uncertainty analyses, we estimate that the benefits of achieving the targets are considerable. Under plausible scenarios, the economic benefits far exceed the necessary investments by endemic country governments and their development partners. Given the higher frequency of NTDs among the poorest households, these investments represent good value for money in the effort to improve well-being, distribute the world's prosperity more equitably and reduce inequity

Beyond Hybridity to the Politics of Scale: International Intervention and 'Local' Politics

The evident failures of international peacebuilding and statebuilding interventions (PSBIs) have recently prompted a focus on the interaction between interventions and target societies and states. Especially popular has been the ‘hybridity’ approach, which understands forms of peace and governance emerging through the mixing of local and international agendas and institutions. This article argues that hybridity is a highly problematic optic. Despite contrary claims, hybridity scholarship falsely dichotomizes ‘local’ and ‘international’ ideal-typical assemblages, and incorrectly presents outcomes as stemming from conflict and accommodation between them. Scholarship in political geography and state theory provides better tools for explaining PSBIs’ outcomes as reflecting socio-political contestation over power and resources. We theorize PSBIs as involving a politics of scale, where different social forces promote and resist alternative scales and modes of governance, depending on their interests and agendas. Contestation between these forces, which may be located at different scales and involved in complex, tactical, multi-scalar alliances, explains the uneven outcomes of international intervention. We demonstrate this using a case study of East Timor, focusing on decentralization and land policy

Spectroscopy of 91Zr51 at medium to high spins

Identification of near-yrast states in the β-stable nucleus 91Zr51 has been carried out using the fusion evaporation reaction, 82Se(13C,4n)91Zr at an incident beam energy of 50 MeV. States above the reported r = 6 μs, Iπ = 21/2+ isomeric level at Ex = 3167 keV have been identified for the first time in this work, a tentative decay scheme of near-yrast states to excitation energies in excess of 10 MeV has been constructed. These states are of relevance to shell model structures formed via limited valence-space configurations in this semi-magic N = 51 nucleus

A steady-state genetic algorithm with resampling for noisy inventory control

Noisy fitness functions occur in many practical applications of evolutionary computation. A standard technique for solving these problems is fitness resampling but this may be inefficient or need a large population, and combined with elitism it may overvalue chromosomes or reduce genetic diversity. We describe a simple new resampling technique called Greedy Average Sampling for steady-state genetic algorithms such as GENITOR. It requires an extra runtime parameter to be tuned, but does not need a large population or assumptions on noise distributions. In experiments on a well-known Inventory Control problem it performed a large number of samples on the best chromosomes yet only a small number on average, and was more effective than four other tested technique

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele