3,935 research outputs found
The Hippocampus is Preferentially Associated with Memory for Spatial Context
The existence of a functional-anatomic dissociation for retrieving item versus contextual information within subregions of the medial temporal lobe (MTL) is currently under debate. We used a spatial source memory paradigm during event-related functional magnetic resonance imaging to investigate this issue. At study, abstract shapes were presented to the left or right of fixation. During test, old and new shapes were presented at fixation. Participants responded whether each shape had been previously presented on the “left,” the “right,” or was “new.” Activity associated with contextual memory (i.e., source memory) was isolated by contrasting accurate versus inaccurate memory for spatial location. Item-memory-related activity was isolated by contrasting accurate item recognition without contextual memory with forgotten items. Source memory was associated with activity in the hippocampus and parahippocampal cortex. Although item memory was not associated with unique MTL activity at our original threshold, a region-of-interest (ROI) analysis revealed item-memory-related activity in the perirhinal cortex. Furthermore, a functional-anatomic dissociation within the parietal cortex for retrieving item and contextual information was not found in any of three ROIs. These results support the hypothesis that specific subregions in the MTL are associated with item memory and memory for context
Imperfect observations in ecological studies
Every ecological data set is the result of sampling the biota at sampling locations. Such samples are rarely a census of the biota at the sampling locations and so will inherently contain biases. It is crucial to account for the bias induced by sampling if valid inference on biodiversity quantities is to be drawn from the observed data. The literature on accounting for sampling effects is large, but most are dedicated to the specific type of inference required, the type of analysis performed and the type of survey undertaken. There is no general and systematic approach to sampling. Here, we explore the unification of modelling approaches to account for sampling. We focus on individuals in ecological communities as the fundamental sampling element, and show that methods for accounting for sampling at the species level can be equated to individual sampling effects. Particular emphasis is given to the case where the probability of observing an individual, when it is present at the site sampled, is less than one. We call these situations ‘imperfect observations’. The proposed framework is easily implemented in standard software packages. We highlight some practical benefits of this formal framework: the ability of predicting the true number of individuals using an expectation that conditions on the observed data, and designing appropriate survey plans accounting forPublisher PDFPeer reviewe
THE ECONOMIC CONSEQUENCES OF EUROPEAN UNION A Symposium on Some Policy Aspects. THE ECONOMIC AND SOCIAL RESEARCH INSTITUTE, DUBLIN, 1986
The papers published here, together with the Matthews paper,
address some of the economic questions on which discussion of
further European integration should be based. Will European
prosperity bring Irish prosperity? Does a free market threaten
traditional Irish industry, or aid new Irish industry, or both?
How can a small peripheral economy survive and prosper in a
monetary union? How much autonomy does an Irish
government at present enjoy in monetary and fiscal policy? Are
Ireland’s interests close to the Community average? Questions
such as these are asked by politicians, who expect economists
to answer them; economists tend to react by asking further
questions, by demanding quantitative data on which to base their
assessments. It is one of the positive points of these papers that
the economists have been willing to be drawn out on some of
these current issues of political economy, even if others remain
to be tackled. I believe that the burden of these papers does not
suggest any reason for doubting that in the long term it is in
Ireland’s interest that the Community should be economically
and politically strong, and that Ireland should be a full partner
in that Community
Video Manipulation Techniques for the Protection of Privacy in Remote Presence Systems
Systems that give control of a mobile robot to a remote user raise privacy
concerns about what the remote user can see and do through the robot. We aim to
preserve some of that privacy by manipulating the video data that the remote
user sees. Through two user studies, we explore the effectiveness of different
video manipulation techniques at providing different types of privacy. We
simultaneously examine task performance in the presence of privacy protection.
In the first study, participants were asked to watch a video captured by a
robot exploring an office environment and to complete a series of observational
tasks under differing video manipulation conditions. Our results show that
using manipulations of the video stream can lead to fewer privacy violations
for different privacy types. Through a second user study, it was demonstrated
that these privacy-protecting techniques were effective without diminishing the
task performance of the remote user.Comment: 14 pages, 8 figure
Domain wall displacement by remote spin-current injection
We demonstrate numerically the ability to displace a magnetic domain wall by
a remote spin current injection. We consider a long and narrow magnetic
nanostripe with a single domain wall (DW). The spin-polarized current is
injected perpendicularly to the plane of the film (CPP) through a small
nanocontact which is located at certain distance from the domain wall initial
position. We show theoretically that the DW motion can be initiated not only by
conventional spin-transfer torque but also by indirect spin-torque, created by
a remote spin-current injection and then transferred to the DW by the
exchange-spring mechanism. An analytical description of this effect is
proposed. This finding may lead to a solution of bottleneck problems of DW
motion-based spintronic and neuromorphic devices with perpendicular
spin-current injection.Comment: 6 pages, 4 figure
Quantum oscillations in the parent pnictide BaFeAs : itinerant electrons in the reconstructed state
We report quantum oscillation measurements that enable the direct observation
of the Fermi surface of the low temperature ground state of \ba122. From these
measurements we characterize the low energy excitations, revealing that the
Fermi surface is reconstructed in the antiferromagnetic state, but leaving
itinerant electrons in its wake. The present measurements are consistent with a
conventional band folding picture of the antiferromagnetic ground state,
placing important limits on the topology and size of the Fermi surface.Comment: 5 pages, 3 figure
Diagnostic and decision-support tools for effective faecal sludge management (FSM) services
Achieving effective faecal sludge management (FSM) from on-site sanitation systems is critical to improving sanitation in urban settlements. Research conducted in 2014-16 by OPM Ltd and WEDC, on behalf of and with the World Bank WSP, used extensive primary data from five cities in the global South to develop a comprehensive suite of FSM diagnostic and decision-support tools. This paper describes the development and use of the tools, while illustrating two key tools. The resulting suite of tools, together with associated resources, provides a comprehensive and usable basis to help guide FSM intervention options, informed by an understanding of existing FSM services, within the context of the enabling environment and political economy realities of the city
Redefinition of the Upper Pennsylvanian Virgilian Series in Kansas
The Virgilian Series was defined nearly 60 years ago to include those rocks lying between the Missourian Series and the base of the Permian System. In the type area in east-central Kansas, the Virgilian Series comprised the Douglas, Shawnee, and Wabaunsee Groups. In Kansas, the upper boundary of the Virgilian (Pennsylvanian-Permian boundary) was placed at the top of the Brownville Limestone Member on the basis of what was then believed to be a regional disconformity rather than on paleontological criteria. Recent advances in fusulinid and conodont biostratigraphy provide tentative criteria upon which to effect a change in the placement of the Virgilian-Permian boundary. It is now generally agreed that the base of the Permian System is approximated by the first occurrence of Pseudoschwagerina, an inflated schwagerinid. Furthermore, the Subcommission on Permian Stratigraphy has informally agreed that the base of the Permian should coincide with the first occurrence of the conodont species Streptognathodus barskovi. Inflated schwagerinids (Paraschwagerina kansasensis) first occur along with evolutionary changes in the Conodonta in the Neva Limestone of the Council Grove Group. Consequently, the Virgilian Series is herein redefined to include rocks present between the top of the Missourian Series and the base of the Neva Limestone.
To increase compatibility between chronostratigraphic and lithostratigraphic nomenclature, the following changes are made: I) the Admire Group is redefined to include rocks between the base of the Onaga Shale and the base of the Neva Limestone; 2) the Admire is reassigned to the upper Virgilian Series; 3) the Neva Limestone is elevated to formational status; 4) the Grenola Limestone is redefined to include strata between the top of the Roca Shale and the base of the Neva Limestone; 5) the overlying Council Grove Group is redefined to include strata lying between the base of the Neva Limestone and the base of the Chase Group; and 6) regionally the base of the emended Council Grove Group marks the base of the Permian System. The emended Council Grove Group is lower Wolfcampian in age and is time equivalent with the Neal Ranch Formation of the west Texas type Wolfcampian
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