1,743 research outputs found
Neural responses to ambiguity involve domain-general and domain-specific emotion processing systems
Extant research has examined the process of decision making under uncertainty, specifically in situations of ambiguity. However, much of this work has been conducted in the context of semantic and low-level visual processing. An open question is whether ambiguity in social signals (e.g., emotional facial expressions) is processed similarly or whether a unique set of processors come on-line to resolve ambiguity in a social context. Our work has examined ambiguity using surprised facial expressions, as they have predicted both positive and negative outcomes in the past. Specifically, whereas some people tended to interpret surprise as negatively valenced, others tended toward a more positive interpretation. Here, we examined neural responses to social ambiguity using faces (surprise) and nonface emotional scenes (International Affective Picture System). Moreover, we examined whether these effects are specific to ambiguity resolution (i.e., judgments about the ambiguity) or whether similar effects would be demonstrated for incidental judgments (e.g., nonvalence judgments about ambiguously valenced stimuli). We found that a distinct task control (i.e., cingulo-opercular) network was more active when resolving ambiguity. We also found that activity in the ventral amygdala was greater to faces and scenes that were rated explicitly along the dimension of valence, consistent with findings that the ventral amygdala tracks valence. Taken together, there is a complex neural architecture that supports decision making in the presence of ambiguity: (a) a core set of cortical structures engaged for explicit ambiguity processing across stimulus boundaries and (b) other dedicated circuits for biologically relevant learning situations involving faces
Analysis of maritime support vessels and acquisition methods utilized to support maritime irregular warfare
MBA Professional ReportAs the U.S. military continuously aligns the appropriate platforms to conduct Maritime Irregular Warfare (MIW), Special Operations Command (SOCOM) has leased/chartered civilian ships to provide the appropriate vessels needed to support operations in Operation Enduring Freedom-Philippines (OEF-P). The framework of this study showcases three specific vessels with their corresponding capabilities on cost per day basis. Our findings and analyses may aid commanders in determining the most appropriate vessel and cost-effective acquisition method to accomplish specific MIW missions in not only OEF-P, but also in other MIW environments. Based on the analysis and recommendations presented in this project, decision makers in this arena will have a mechanism from which to make a more informed decision regarding the acquisition of vessels supporting MIW. Decision makers will be able to evaluate various potential MIW scenarios; identify specific vessel capabilities to meet their operational requirements; and acquire vessels more cost-effectively based on total daily rate costs.http://archive.org/details/analysisofmariti109451051
Infrared Observations of the Helix Planetary Nebula
We have mapped the Helix (NGC 7293) planetary nebula (PN) with the IRAC instrument on the Spitzer Space Telescope. The Helix is one of the closest bright PNs and therefore provides an opportunity to resolve the small-scale structure in the nebula. The emission from this PN in the 5.8 and 8 Όm IRAC bands is dominated by the pure rotational lines of molecular hydrogen, with a smaller contribution from forbidden line emission such as [Ar III] in the ionized region. The IRAC images resolve the "cometary knots," which have been previously studied in this PN. The "tails" of the knots and the radial rays extending into the outer regions of the PN are seen in emission in the IRAC bands. IRS spectra on the main ring and the emission in the IRAC bands are consistent with shock-excited H_2 models, with a small (~10%) component from photodissociation regions. In the northeast arc, the H_2 emission is located in a shell outside the Hα emission
VascularĂą targeted nanocarriers: design considerations and strategies for successful treatment of atherosclerosis and other vascular diseases
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134422/1/wnan1414_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134422/2/wnan1414.pd
Sharing Emergency Planning Assumptions: Management Views Differ
Effective disaster management requires advanced planning. News media centers, public information hot-lines, and on-site volunteer procedures must be established in anticipation of large scale emergencies. In the following article, Kartez reviews the disaster planning programs and policies of 250 public agencies associated with disaster-prone communities. The study describes managerial perspectives of disaster planning policy. The article is a guide for planners concerned with the complexities of community crisis mitigation
Base excision repair apurinic/apyrimidinic endonucleases in apicomplexan parasite Toxoplasma gondii
DNA repair is essential for cell viability and proliferation. In addition to reactive oxygen produced as a byproduct of their own metabolism, intracellular parasites also have to manage oxidative stress generated as a defense mechanism by the host. The spontaneous loss of DNA bases due to hydrolysis and oxidative DNA damage in intracellular parasites is great, but little is known about the type of DNA repair machineries that exist in these early-branching eukaryotes. However, it is clear, processes similar to DNA base excision repair (BER) must exist to rectify spontaneous and host-mediated damage in Toxoplasma gondii. Here we report that T. gondii, an opportunistic protozoan pathogen, possesses two apurinic/apyrimidinic (AP) endonucleases that function in DNA BER. We characterize the enzymatic activities of Toxoplasma exonuclease III (ExoIII, or Ape1) and endonuclease IV (EndoIV, or Apn1), designated TgAPE and TgAPN, respectively. Over-expression of TgAPN in Toxoplasma conferred protection from DNA damage, and viable knockouts of TgAPN were not obtainable. We generated an inducible TgAPN knockdown mutant using a ligand-controlled destabilization domain to establish that TgAPN is critical for Toxoplasma to recover from DNA damage. The importance of TgAPN and the fact that humans lack any observable APN family activity highlights TgAPN as a promising candidate for drug development to treat toxoplasmosis
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