MAO-A and the EEG Recognition Memory Signal in Left Parietal Cortex

A key part of episodic memory, or memory for the events of our lives, is recognition memory. Recognition memory is the ability to remember previously encountered stimuli. Studies have linked recognition memory to the old/new effect, an EEG indicator of stimulus familiarity. Monoamine oxidase A (MAO-A) is an enzyme that catalyzes monoamines, leading to the depletion of norepinephrine, epinephrine, serotonin, and dopamine. MAO-A is more efficiently transcribed in individuals with a 4 repeating sequence variation (4R) of the MAO-A gene leading to less monoamine availability. As many of these monoamines have been linked to episodic memory, we hypothesized that individuals homozygous for the 4R MAO-A polymorphism would show differences in mean EEG signal amplitudes during recognition memory. EEG data was recorded as participants viewed both new words and words that had been previously presented. Our results show that mean peak amplitudes over the left parietal cortex 500-800 ms post-stimulus presentation for hits were greater than those for correct rejections, indicating the old/new effect. Critically, our results revealed an interaction between mean hit and correct rejection amplitude over the left parietal cortex and MAO-A group. Individuals homozygous for the 4R variation (the High MAO-A group) do not show an old/new effect due to increased correct rejection amplitudes. These results suggest that less monoamine availability leads to new stimuli being identified as old by the left parietal cortex

Agricultural Health and Safety: A Research Agenda for Agricultural Economists

Replaced with revised version of paper 01/26/06.Health Economics and Policy, Teaching/Communication/Extension/Profession,

The Compact Clause and National Popular Vote: Implications for the Federal Structure

The Electoral College is a vital part of the Founders\u27 federalist Constitution. NPV pretends to be in line with this federalist structure, but its claims are disingenuous. In reality, NPV would destroy the federalist nature of the presidential election process. A system that today operates as a combination of democracy and federalism would change: It would instead operate as pure democracy. This change from federalism to pure democracy would be made even if a majority of states disapproved. As a policy matter, eliminating federalism from the presidential election process will have many practical consequences that make such a change inadvisable. However, the disruption of federalism also has several legal ramifications that cannot be ignored. NPV\u27s compact may not withstand scrutiny under Articles II, IV and V of the Constitution. It may also fail the Equal Protection requirements in the Fourteenth Amendment. But assuming it survives these challenges, it will also run into problems with Article I, Section 10 of the Constitution. The Compact Clause\u27s requirement of congressional approval will apply to this compact even under today\u27s lenient U.S. Steel standard. If NPV\u27s compact is eventually presented to Congress for approval, Congress should decline to give its consent. Such radical change should never be made through a simple interstate compact and bare majorities in Congress. If this change is to be made, it should be made with the full cooperation and knowledge of the American people. The constitutional amendment process would require widespread debate and acquiescence before federalism is eliminated from the presidential election system. The Founders would have expected nothing less

Software for interpreting cardiopulmonary exercise tests

<p>Abstract</p> <p>Background</p> <p>Cardiopulmonary exercise testing (CPET) has become an important modality for the evaluation and management of patients with a diverse array of medical problems. However, interpreting these tests is often difficult and time consuming, requiring significant expertise.</p> <p>Methods</p> <p>We created a computer software program (XINT) that assists in CPET interpretation. The program uses an integrative approach as recommended in the Official Statement of the American Thoracic Society/American College of Chest Physicians (ATS/ACCP) on Cardiopulmonary Exercise Testing. In this paper we discuss the principles behind the software. We also provide the detailed logic in an accompanying file (Additional File <supplr sid="S1">1</supplr>). The actual program and the open source code are also available free over the Internet at <url>http://www.xint.org</url>. For convenience, the required download files can also be accessed from this article.</p> <suppl id="S1"> <title> <p>Additional file 1</p> </title> <text> <p>XINTlogic. This file provides the detailed logic used by the XINT program. The variable names are described in Table <tblr tid="T1">1</tblr>. The actual source code may also be read directly simply by opening the source code with a text editor.</p> </text> <file name="1471-2466-7-15-S1.doc"> <p>Click here for file</p> </file> </suppl> <p>Results</p> <p>To test the clinical usefulness of XINT, we present the computer generated interpretations of the case studies discussed in the ATS/ACCP document in another accompanying file (Additional File <supplr sid="S2">2</supplr>). We believe the interpretations are consistent with the document's criteria and the interpretations given by the expert panel.</p> <suppl id="S2"> <title> <p>Additional file 2</p> </title> <text> <p>XINTinterpretations. These are the XINT generated reports based on the five examples provided in the ATS/ACCP statement on cardiopulmonary exercise testing <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p> </text> <file name="1471-2466-7-15-S2.doc"> <p>Click here for file</p> </file> </suppl> <p>Conclusion</p> <p>Computers have become an integral part of modern life. Peer-reviewed scientific journals are now able to present not just medical concepts and experimental studies, but actual functioning medical interpretive software. This has enormous potential to improve medical diagnoses and patient care. We believe XINT is such a program that will give clinically useful interpretations when used by the medical community at large.</p

The 2F-modules for nearly simple groups

AbstractWe complete the classification of irreducible 2F-modules for groups of Lie type acting in the natural characteristic by dealing with the three open cases from [R.M. Guralnick, G. Malle, Classification of 2F-modules, II, in: C. Ho, P. Sin, P. Tiep, A. Turull (Eds.), Finite Groups 2003, Proceedings of the Gainesville Conference on Finite Groups, March 6–12, 2003, de Gruyter, Berlin, 2004, pp. 117–183]. We also finish the classification of such modules for almost quasi-simple groups, and show that in all cases there is an offender with cubic action

UV Imaging Polarimetry of the Seyfert 2 Galaxy Mrk 3

We present UV imaging polarimetry data of the Seyfert 2 galaxy Mrk 3 taken by the Hubble Space Telescope. The polarized flux is found to be extended to ~1 kpc from the nucleus, and the position angles of polarization are centrosymmetric, confirming that the polarization is caused by scattering. We determine the location of the hidden nucleus as the center of this centrosymmetric pattern. From the polarization images taken in two broad bands, we have obtained the color distribution of the polarized flux. Some regions have blue polarized flux, consistent with optically-thin dust scattering, but some bright knots have a color similar to that of Seyfert 1 nucleus. Also, the recent Chandra X-ray observation suggests that the ratio of scattered UV flux to scattered X-ray flux is rather similar to the intrinsic UV/X-ray ratio in a Seyfert 1 nucleus, if the observed extended X-ray continuum is scattered light. While the scattered X-ray would be essentially from electron scattering, the UV slope and UV/X-ray ratio both being similar to Seyfert 1's would lead to two possibilities as to the nature of the UV scatterers. One is that the UV may also be scattered by electrons, in which case the scattering gas is somehow dust-free. The other is that the UV is scattered by dust grains, but the wavelength-independent UV scattering with low efficiency indicated by the UV slope and UV/X-ray ratio would suggest that the grains reside in UV-opaque clouds, or the dust might be mainly composed of large grains and lacks small-grain population.Comment: 15 pages, 8 figures (plus 2 color versions of grayscale figures), To appear in ApJ; minor corrections for the proofs of the manuscrip

Hippocampus and retrosplenial cortex combine path integration signals for successful navigation

The current study used fMRI in humans to examine goal-directed navigation in an open field environment. We designed a task that required participants to encode survey-level spatial information and subsequently navigate to a goal location in either first person, third person, or survey perspectives. Critically, no distinguishing landmarks or goal location markers were present in the environment, thereby requiring participants to rely on path integration mechanisms for successful navigation. We focused our analysis on mechanisms related to navigation and mechanisms tracking linear distance to the goal location. Successful navigation required translation of encoded survey-level map information for orientation and implementation of a planned route to the goal. Our results demonstrate that successful first and third person navigation trials recruited the anterior hippocampus more than trials when the goal location was not successfully reached. When examining only successful trials, the retrosplenial and posterior parietal cortices were recruited for goal-directed navigation in both first person and third person perspectives. Unique to first person perspective navigation, the hippocampus was recruited to path integrate self-motion cues with location computations toward the goal location. Last, our results demonstrate that the hippocampus supports goal-directed navigation by actively tracking proximity to the goal throughout navigation. When using path integration mechanisms in first person and third person perspective navigation, the posterior hippocampus was more strongly recruited as participants approach the goal. These findings provide critical insight into the neural mechanisms by which we are able to use map-level representations of our environment to reach our navigational goals