2,119 research outputs found

    Coevolutionary Investments in Human Speech and Trade

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    We propose a novel explanation for the emergence of language in modern humans, and the lack thereof in other hominids. A coevolutionary process, where trade facilitates speech and speech facilitates trade, driven by expectations and potentially influenced by geography, gives rise to multiple stable development trajectories. While the trade-speech equilibrium is not an inevitable outcome for modern humans, we do find that it is a relatively likely result given that our species evolved in Africa under climatic conditions supporting relatively high population densities.Institutional and Behavioral Economics,

    fMRI biomarkers of social cognitive skills training in psychosis: Extrinsic and intrinsic functional connectivity.

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    Social cognitive skills training interventions for psychotic disorders have shown improvement in social cognitive performance tasks, but little was known about brain-based biomarkers linked to treatment effects. In this pilot study, we examined whether social cognitive skills training could modulate extrinsic and intrinsic functional connectivity in psychosis using functional magnetic resonance imaging (fMRI). Twenty-six chronic outpatients with psychotic disorders were recruited from either a Social Cognitive Skills Training (SCST) or an activity- and time-matched control intervention. At baseline and the end of intervention (12 weeks), participants completed two social cognitive tasks: a Facial Affect Matching task and a Mental State Attribution Task, as well as resting-state fMRI (rs-fMRI). Extrinsic functional connectivity was assessed using psychophysiological interaction (PPI) with amygdala and temporo-parietal junction as a seed region for the Facial Affect Matching Task and the Mental State Attribution task, respectively. Intrinsic functional connectivity was assessed with independent component analysis on rs-fMRI, with a focus on the default mode network (DMN). During the Facial Affect Matching task, we observed stronger PPI connectivity in the SCST group after intervention (compared to baseline), but no treatment-related change in the Control group. Neither group showed treatment-related changes in PPI connectivity during the Mental State Attribution task. During rs-fMRI, we found treatment-related changes in the DMN in the SCST group, but not in Control group. This study found that social cognitive skills training modulated both extrinsic and intrinsic functional connectivity in individuals with psychotic disorders after a 12-week intervention. These findings suggest treatment-related changes in functional connectivity as a potential brain-based biomarker of social cognitive skills training

    Competitive Exclusion, Diversification, and the Origins of Agriculture

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    The beginnings of agriculture, or the agricultural revolution, is now recognized to be the widespread adoption of known practices – a change in behavior – as opposed to a phenomenon of discovery and innovation. In this paper, we combine elements of three theories—climate change, property rights, and competitive exclusion—to create a paleoeconomic model of agriculture and its diffusion. We focus on climate change as a necessary trigger, which combined with group property rights and competitive exclusion processes produced conditions sufficient for the diffusion of early agriculture. In contrast to other models in which farming emerges as technological progress or climate makes it a more productive option than hunting, farming emerges in our model even if farmers are poor hunters and cannot sustain themselves with agriculture alone. Moreover, the strategy of farming can invade the system even if farmers initially generate lower per capita consumption than hunters. The key is that the simple innovation of property rights over an immobile resource can help to insulate farmers from competitive ecological pressures.Farm Management, Research and Development/Tech Change/Emerging Technologies,

    Disturbances in the spontaneous attribution of social meaning in schizophrenia

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    Background. Schizophrenia patients show disturbances on a range of tasks that assess mentalizing or 'Theory of Mind' (ToM). However, these tasks are often developmentally inappropriate, make large demands on verbal abilities and explicit problem-solving skills, and involve after-the-fact reflection as opposed to spontaneous mentalizing. Method. To address these limitations, 55 clinically stable schizophrenia out-patients and 44 healthy controls completed a validated Animations Task designed to assess spontaneous attributions of social meaning to ambiguous abstract visual stimuli. In this paradigm, 12 animations depict two geometric shapes' interacting' with each other in three conditions: (1) ToM interactions that elicit attributions of mental states to the agents, (2) Goal-Directed (GO) interactions that elicit attributions of simple actions, and (3) Random scenes in which no interaction occurs. Verbal descriptions of each animation are rated for the degree of Intentionality attributed to the agents and for accuracy. Results. Patients had lower Intentionality ratings than controls for ToM and GO scenes but the groups did not significantly differ for Random scenes. The descriptions of the patients less closely matched the situations intended by the developers of the task. Within the schizophrenia group, performance on the Animations Task showed minimal associations with clinical symptoms. Conclusions. Patients demonstrated disturbances in the spontaneous attribution of mental states to abstract visual stimuli that normally evoke such attributions. Hence, in addition to previously established impairment on mentalizing tasks that require logical inferences about others' mental states, individuals with schizophrenia show disturbances in implicit aspects of mentalizing

    The SED of the TeV BLLac 1ES 1426+428 after correction for the TeV--IR absorption

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    The recent HEGRA detection and spectrum of 1ES 1426+428 at TeV energies, once corrected for absorption using present estimates of the diffuse extragalactic IR background, suggest that the high energy peak of the Spectral Energy Distribution (SED) could be much higher than the synchrotron one (Lc/Ls>10L_c/L_s>10), and lie at energies above 8-10 TeV. To see if such an SED could be accounted for, we have applied a "finite injection time" SSC model, and present here some preliminary results. Within this model, we found the need of an external ("ambient") contribution to the energy density of seed photons, in order to account for both the high Compton dominance and the hard spectrum.Comment: 4 pages, 5 figures, to appear in the proceedings of the conference "Relativistic jets in the Chandra and XMM era", Bologna, 23-27/9/02 (New Astr. Rev.

    Asymptotic Dynamics in Quantum Field Theory

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    A crucial element of scattering theory and the LSZ reduction formula is the assumption that the coupling vanishes at large times. This is known not to hold for the theories of the Standard Model and in general such asymptotic dynamics is not well understood. We give a description of asymptotic dynamics in field theories which incorporates the important features of weak convergence and physical boundary conditions. Applications to theories with three and four point interactions are presented and the results are shown to be completely consistent with the results of perturbation theory.Comment: 18 pages, 3 figure

    The effect of Holstein-Friesian genotype and feeding system on selected performance parameters of dairy cows on grass-based systems of milk production in Ireland

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    End of project reportThe overall objective of this project was to assess, the effect of strain of Holstein-Friesian dairy cow, pasture-based feed system (FS) and their interaction on animal performance in terms of milk productivity and lactation profile, body weight (BW), body condition score (BCS), feed intake and energy balance (EB), reproductive performance and overall economic profitability

    An Advocacy Approach for More Effective Program Delivery And Coordination: A Case Study of Maine\u27s Housing Rehab Techs

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    A detailed case analysis of the Maine Housing Rehabilitation Project provides an exploratory observation of the innovative use of human resources at the federal, state and regional levels through an evolutionary development process of housing rehabilitation technicians. Functioning largely as advocate planners and human service delivery administrators through self-expanded roles, these individuals were able to promote change in the context of this intergovernmental environment. The analysis presented here reveals findings of intrastate regional differences between the urban and rural areas. Low income citizens appear to be the main beneficiaries of a proactive style of leadership that was performed by the most productive rehab techs. The autonomy of their roles afforded all technicians a degree of freedom to produce different results through experimentation
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