Emory University

About: Emory University is a education organization based out in Atlanta, Georgia, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 51959 authors who have published 122469 publications receiving 6010698 citations.

Causal reasoning with forces

Abstract: Causal composition allows people to generate new causal relations by combining existing causal knowledge. We introduce a new computational model of such reasoning, the force theory, which holds that people compose causal relations by simulating the processes that join forces in the world, and compare this theory with the mental model theory (Khemlani, Barbey, & Johnson-Laird, 2014) and the causal model theory (Sloman, Barbey, & Hotaling, 2009), which explain causal composition on the basis of mental models and structural equations, respectively. In one experiment, the force theory was uniquely able to account for people’s ability to compose causal relationships from complex animations of real-world events. In three additional experiments, the force theory did as well as or better than the other two theories in explaining the causal compositions people generated from linguistically presented causal relations. Implications for causal learning and the hierarchical structure of causal knowledge are discussed.

Prevalence and patterns of cognitive impairment in sporadic ALS.

Abstract: Objective: To investigate the prevalence and nature of cognitive changes associated with sporadic amyotrophic lateral sclerosis (ALS) using a large scale study. Methods: Consecutive patients with sporadic ALS (n = 279) underwent comprehensive neurologic evaluation and neuropsychological testing. Testing data from normal controls (n = 129) were used for classification and comparison purposes. Results: On non-motor, non-speed-dependent tasks, 51% of patients with ALS had evidence of cognitive impairment compared to 5% of controls. Cluster analysis suggested four patient subgroups: 49% intact, 32% with mild impairment, 13% with moderate impairment, and 6% with severe impairment. Forty-one patients (15%) met criteria for frontotemporal dementia (FTD). ALS patient subgroups, excluding the intact group, performed significantly lower on tests of executive function and memory than normal controls. Patients with more severe disease also had deficits in confrontation naming. Although memory function declined with increasing severity of overall cognitive impairment, only two patients had the severe memory loss typical of Alzheimer disease. Cognitive impairment was correlated with clinical measures of word-finding, phrase length, and motor programming. Cognitive impairment was not correlated with depression scores or severity or duration of motor or bulbar symptoms. Patients with bulbar vs limb-onset ALS were not different in either level of impairment or pattern of performance. Conclusions: These data confirm the presence of cognitive impairment in 50% of patients with ALS and particularly implicate executive dysfunction and mild memory decline in the disease process. More severe impairment occurs in a subset of patients with ALS and has features consistent with FTD.

Comparative genomics of the neglected human malaria parasite Plasmodium vivax

Abstract: The human malaria parasite Plasmodium vivax is responsible for 25-40% of the approximately 515 million annual cases of malaria worldwide. Although seldom fatal, the parasite elicits severe and incapacitating clinical symptoms and often causes relapses months after a primary infection has cleared. Despite its importance as a major human pathogen, P. vivax is little studied because it cannot be propagated continuously in the laboratory except in non-human primates. We sequenced the genome of P. vivax to shed light on its distinctive biological features, and as a means to drive development of new drugs and vaccines. Here we describe the synteny and isochore structure of P. vivax chromosomes, and show that the parasite resembles other malaria parasites in gene content and metabolic potential, but possesses novel gene families and potential alternative invasion pathways not recognized previously. Completion of the P. vivax genome provides the scientific community with a valuable resource that can be used to advance investigation into this neglected species.

What's different about social media networks? a framework and research agenda

Abstract: In recent years, we have witnessed the rapid proliferation and widespread adoption of a new class of information technologies, commonly known as social media. Researchers often rely on social network analysis (SNA) when attempting to understand these technologies, often without considering how the novel capabilities of social media platforms might affect the underlying theories of SNA, which were developed primarily through studies of offline social networks. This article outlines several key differences between traditional offline social networks and online social media networks by juxtaposing an established typology of social network research with a well-regarded definition of social media platforms that articulates four key features. The results show that at four major points of intersection, social media has considerable theoretical implications for SNA. In exploring these points of intersection, this study outlines a series of theoretically distinct research questions for SNA in social media contexts. These points of intersection offer considerable opportunities for researchers to investigate the theoretical implications introduced by social media and lay the groundwork for a robust social media agenda potentially spanning multiple disciplines.