University of Iowa

About: University of Iowa is a education organization based out in Iowa City, Iowa, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 49229 authors who have published 109171 publications receiving 5021465 citations. The organization is also known as: UI & The University of Iowa.

Factors Effecting Late Results After Meniscectomy

Abstract: Meniscectomy has frequently been performed on the assumption that the absence of a meniscus has little effect on joint function. Statistical analysis of data obtained from the histories, physical examinations, and roentgenographic and electrogoniometric studies of ninety-nine patients with a mean follow-up of 17.5 years after meniscectomy revealed a high incidence of poor results, degenerative arthritis, ligamentous laxity, and decreased stance-phase flexion. A meniscus should be removed only when it is definitely abnormal.

Electrophysiological measurement of rapid shifts of attention during visual search

Abstract: The perception of natural visual scenes that contain many objects poses computational problems that are absent when objects are perceived in isolation1. Vision researchers have captured this attribute of real-world perception in the laboratory by using visual search tasks, in which subjects search for a target object in arrays containing varying numbers of non-target distractor objects. Under many conditions, the amount of time required to detect a visual search target increases as the number of objects in the stimulus array increases, and some investigators have proposed that this reflects the serial application of attention to the individual objects in the array2,3. However, other investigators have argued that this pattern of results may instead be due to limitations in the processing capacity of a parallel processing system that identifies multiple objects concurrently4,5. Here we attempt to address this longstanding controversy by using an electrophysiological marker of the moment-by-moment direction of attention — the N2pc component of the event-related potential waveform — to show that attention shifts rapidly among objects during visual search.

Irrational Economic Decision-Making after Ventromedial Prefrontal Damage: Evidence from the Ultimatum Game

Abstract: Emotion regulation is often critical for adaptive decision making. Here, we investigate whether emotion regulation defects following focal prefrontal brain damage are associated with exceptionally irrational economic decision making in situations of unfair treatment. In the Ultimatum Game, two players are given one opportunity to split a sum of money. One player (the proposer) offers a portion of the money to the second player (the responder) and keeps the rest. The responder can either accept the offer (in which case both players split the money as proposed) or reject the offer (in which case both players get nothing). Relatively low Ultimatum offers are often rejected, and this “irrational” behavior has been attributed to an emotional reaction to unfair treatment. Using the lesion method, we tested the hypothesis that damage to ventromedial prefrontal cortex (VMPC), an area critical for the modulation of emotional reactions, would result in exaggerated irrational economic decisions. Subjects acted as the responder to 22 different proposers who offered various splits of $10. Offers ranged from fair (give $5, keep $5) to extremely unfair (give $1, keep $9). The rejection rate of the VMPC group was higher than the rejection rates of the comparison groups for each of the most unfair offers ($7/$3, $8/$2, $9/$1). These results suggest that emotion regulation processes subserved by VMPC are a critical component of normal economic decision making.

Mechanism of NLRP3 inflammasome activation

Abstract: Inflammasomes continue to generate interest in an increasing number of disciplines owing to their unique ability to integrate a myriad of signals from pathogen- and damage-associated molecular patterns into a proinflammatory response This potent caspase-1-dependent process is capable of activating the innate immune system, initiating pyroptosis (an inflammatory form of programmed cell death), and shaping adaptive immunity The NLRP3 inflammasome is the most thoroughly studied of the inflammasome complexes that have been described thus far, perhaps owing to its disparate assortment of agonists This review highlights our current understanding of the mechanisms of both priming and activation of the NLRP3 inflammasome

Wave acceleration of electrons in the Van Allen radiation belts

Abstract: The Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer radiation belt was depleted and then re-formed closer to the Earth, that the long established theory of acceleration by radial diffusion is inadequate; the electrons are accelerated more effectively by electromagnetic waves at frequencies of a few kilohertz. Wave acceleration can increase the electron flux by more than three orders of magnitude over the observed timescale of one to two days, more than sufficient to explain the new radiation belt. Wave acceleration could also be important for Jupiter, Saturn and other astrophysical objects with magnetic fields.