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101.
J. Randall Flanagan Gerben Rotman Andreas F. Reichelt Roland S. Johansson 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2013,368(1628)
When watching an actor manipulate objects, observers, like the actor, naturally direct their gaze to each object as the hand approaches and typically maintain gaze on the object until the hand departs. Here, we probed the function of observers'' eye movements, focusing on two possibilities: (i) that observers'' gaze behaviour arises from processes involved in the prediction of the target object of the actor''s reaching movement and (ii) that this gaze behaviour supports the evaluation of mechanical events that arise from interactions between the actor''s hand and objects. Observers watched an actor reach for and lift one of two presented objects. The observers'' task was either to predict the target object or judge its weight. Proactive gaze behaviour, similar to that seen in self-guided action–observation, was seen in the weight judgement task, which requires evaluating mechanical events associated with lifting, but not in the target prediction task. We submit that an important function of gaze behaviour in self-guided action observation is the evaluation of mechanical events associated with interactions between the hand and object. By comparing predicted and actual mechanical events, observers, like actors, can gain knowledge about the world, including information about objects they may subsequently act upon. 相似文献
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103.
In subtropical China, large‐scale phylogeographic comparisons among multiple sympatric plants with similar ecological preferences are scarce, making generalizations about common response to historical events necessarily tentative. A phylogeographic comparison of two sympatric Chinese beeches (Fagus lucida and F. longipetiolata, 21 and 28 populations, respectively) was conducted to test whether they have responded to historical events in a concerted fashion and to determine whether their phylogeographic structure is exclusively due to Quaternary events or it is also associated with pre‐Quaternary events. Twenty‐three haplotypes were recovered for F. lucida and F. longipetiolata (14 each one and five shared). Both species exhibited a species‐specific mosaic distribution of haplotypes, with many of them being range‐restricted and even private to populations. The two beeches had comparable total haplotype diversity but F. lucida had much higher within‐population diversity than F. longipetiolata. Molecular dating showed that the time to most recent common ancestor of all haplotypes was 6.36 Ma, with most haplotypes differentiating during the Quaternary. [Correction added on 14 October 2013, after first online publication: the time unit has been corrected to ‘6.36’.] Our results support a late Miocene origin and southwards colonization of Chinese beeches when the aridity in Central Asia intensified and the monsoon climate began to dominate the East Asia. During the Quaternary, long‐term isolation in subtropical mountains of China coupled with limited gene flow would have lead to the current species‐specific mosaic distribution of lineages. 相似文献
104.
Giulia Andrighetto Jordi Brandts Rosaria Conte Jordi Sabater-Mir Hector Solaz Daniel Villatoro 《PloS one》2013,8(6)
Material punishment has been suggested to play a key role in sustaining human cooperation. Experimental findings, however, show that inflicting mere material costs does not always increase cooperation and may even have detrimental effects. Indeed, ethnographic evidence suggests that the most typical punishing strategies in human ecologies (e.g., gossip, derision, blame and criticism) naturally combine normative information with material punishment. Using laboratory experiments with humans, we show that the interaction of norm communication and material punishment leads to higher and more stable cooperation at a lower cost for the group than when used separately. In this work, we argue and provide experimental evidence that successful human cooperation is the outcome of the interaction between instrumental decision-making and the norm psychology humans are provided with. Norm psychology is a cognitive machinery to detect and reason upon norms that is characterized by a salience mechanism devoted to track how much a norm is prominent within a group. We test our hypothesis both in the laboratory and with an agent-based model. The agent-based model incorporates fundamental aspects of norm psychology absent from previous work. The combination of these methods allows us to provide an explanation for the proximate mechanisms behind the observed cooperative behaviour. The consistency between the two sources of data supports our hypothesis that cooperation is a product of norm psychology solicited by norm-signalling and coercive devices. 相似文献
105.
Earlier migration in males than in females is the commonest pattern in migrating passerines and is positively related to size dimorphism and dichromatism. The early arrival of males is a costly trait that may confer reproductive advantages in terms of better territories and/or mates. Given the physiological cost of migration, early migrants are those in best condition and accordingly the prevalence, load, and/or diversity of parasites is expected to increase in both sexes for late migrants. To test this hypothesis, we sampled 187 trans-Saharan migrant garden warblers Sylvia borin and 64 resident serins Serinus serinus (as a control for potential circannual patterns in parasite load) during spring migration in Spain. We assessed the prevalence of blood parasites (Haemoproteus, Plasmodium, and Leucocytozoon) and the prevalence and load of intestinal parasites (mainly coccidians and spirurids). The relationship between parasite (prevalence, load, and richness) and the timing of passage through a stopover area was tested using generalized linear models. Protandry occurs in the monomorphic garden warbler and males migrated on average 5.5 days before females. Intestinal parasite richness increased with the date of migration. The timing of migration was unrelated to the presence or load of the other parasite groups analyzed. Our results support the idea that the timing of migration is a condition-dependent trait and suggests that multiple intestinal parasite infestations could delay migration in birds. Even in monomorphic species parasites may play a role in sexual selection by delaying the arrival of the most infected individuals at breeding grounds, thereby further increasing the benefits of mating with early-arriving individuals. 相似文献
106.
Gemma Navarro Estefania Moreno Jordi Bonaventura Marc Brugarolas Daniel Farré David Aguinaga Josefa Mallol Antoni Cortés Vicent Casadó Carmen Lluís Sergi Ferre Rafael Franco Enric Canela Peter J. McCormick 《PloS one》2013,8(4)
Under normal conditions the brain maintains a delicate balance between inputs of reward seeking controlled by neurons containing the D1-like family of dopamine receptors and inputs of aversion coming from neurons containing the D2-like family of dopamine receptors. Cocaine is able to subvert these balanced inputs by altering the cell signaling of these two pathways such that D1 reward seeking pathway dominates. Here, we provide an explanation at the cellular and biochemical level how cocaine may achieve this. Exploring the effect of cocaine on dopamine D2 receptors function, we present evidence of σ1 receptor molecular and functional interaction with dopamine D2 receptors. Using biophysical, biochemical, and cell biology approaches, we discovered that D2 receptors (the long isoform of the D2 receptor) can complex with σ1 receptors, a result that is specific to D2 receptors, as D3 and D4 receptors did not form heteromers. We demonstrate that the σ1-D2 receptor heteromers consist of higher order oligomers, are found in mouse striatum and that cocaine, by binding to σ1 -D2 receptor heteromers, inhibits downstream signaling in both cultured cells and in mouse striatum. In contrast, in striatum from σ1 knockout animals these complexes are not found and this inhibition is not seen. Taken together, these data illuminate the mechanism by which the initial exposure to cocaine can inhibit signaling via D2 receptor containing neurons, destabilizing the delicate signaling balance influencing drug seeking that emanates from the D1 and D2 receptor containing neurons in the brain. 相似文献
107.
108.
Luis Alberto Henríquez-Hernández Almudena Valenciano Palmira Foro-Arnalot María Jesús álvarez-Cubero José Manuel Cozar José Francisco Suárez-Novo Manel Castells-Esteve Adriana Ayala-Gil Pablo Fernández-Gonzalo Montse Ferrer Ferrán Guedea Gemma Sancho-Pardo Jordi Craven-Bartle María José Ortiz-Gordillo Patricia Cabrera-Roldán Estefanía Herrera-Ramos Pedro C. Lara 《PloS one》2013,8(7)
Background
Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics.Objective
To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias.Design, Setting, and Participants
A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArray® NT Cycler.Outcome Measurements and Statistical Analysis
Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer.Results and Limitations
We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics.Conclusion
Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out. 相似文献109.
Naeemah Abrahams Shanaaz Mathews Lorna J. Martin Carl Lombard Nadine Nannan Rachel Jewkes 《PLoS medicine》2016,13(4)
BackgroundHomicide of children is a global problem. The under-5-y age group is the second largest homicide age group after 15–19 y olds, but has received little research attention. Understanding age and gender patterns is important for assisting with developing prevention interventions. Here we present an age and gender analysis of homicides among children under 5 y in South Africa from a national study that included a focus on neonaticide and infanticide.ConclusionsHomicide of children is an extreme form or consequence of violence against children. This national study provides one of the first analyses of neonaticide and infanticide by age and gender and shows the failure of reproductive and mental health and social services to identify and help vulnerable mothers. Multi-sectoral prevention strategies are needed. 相似文献
110.