University of California, Irvine

About: University of California, Irvine is a education organization based out in Irvine, California, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 47031 authors who have published 113602 publications receiving 5521832 citations. The organization is also known as: UC Irvine & UCI.

Testing Density Forecasts, With Applications to Risk Management

Abstract: The forecast evaluation literature has traditionally focused on methods of assessing point forecasts. However, in the context of many models of financial risk, interest centers on more than just a single point of the forecast distribution. For example, value-at-risk models that are currently in extremely wide use form interval forecasts. Many other important financial calculations also involve estimates not summarized by a point forecast. Although some techniques are currently available for assessing interval and density forecasts, existing methods tend to display low power in sample sizes typically available. This article suggests a new approach to evaluating such forecasts. It requires evaluation of the entire forecast distribution, rather than a scalar or interval. The information content of forecast distributions combined with ex post realizations is enough to construct a powerful test even with sample sizes as small as 100.

Female and male antisocial trajectories: From childhood origins to adult outcomes

Abstract: This article reports on the childhood origins and adult outcomes of female versus male antisocial behavior trajectories in the Dunedin longitudinal study. Four antisocial behavior trajectory groups were identified among females and males using general growth mixture modeling and included life-course persistent (LCP), adolescent-onset, childhood-limited, and low trajectory groups. During childhood, both LCP females and males were characterized by social, familial and neurodevelopmental risk factors, whereas those on the adolescent-onset pathway were not. At age 32, women and men on the LCP pathway were engaging in serious violence and experiencing significant mental health, physical health, and economic problems. Females and males on the adolescent-onset pathway were also experiencing difficulties at age 32, although to a lesser extent. Although more males than females followed the LCP trajectory, findings support similarities across gender with respect to developmental trajectories of antisocial behavior and their associated childhood origins and adult consequences. Implications for theory, research, and practice are discussed.

Strong exchange and magnetic blocking in N₂³⁻-radical-bridged lanthanide complexes.

Abstract: Single-molecule magnets approach the ultimate size limit for spin-based devices. These complexes can retain spin information over long periods of time at low temperature, suggesting possible applications in high-density information storage, quantum computing and spintronics. Notably, the success of most such applications hinges upon raising the inherent molecular spin-inversion barrier. Although recent advances have shown the viability of lanthanide-containing complexes in generating large barriers, weak or non-existent magnetic exchange coupling allows fast relaxation pathways that mitigate the full potential of these species. Here, we show that the diffuse spin of an N(2)(3-) radical bridge can lead to exceptionally strong magnetic exchange in dinuclear Ln(III) (Ln = Gd, Dy) complexes. The Gd(III) congener exhibits the strongest magnetic coupling yet observed for that ion, while incorporation of the high-anisotropy Dy(III) ion gives rise to a molecule with a record magnetic blocking temperature of 8.3 K at a sweep rate of 0.08 T s(-1).

A Distributed Numerical Approach to Interference Alignment and Applications to Wireless Interference Networks

Abstract: Recent results establish the optimality of interference alignment to approach the Shannon capacity of interference networks at high SNR. However, the extent to which interference can be aligned over a finite number of signalling dimensions remains unknown. Another important concern for interference alignment schemes is the requirement of global channel knowledge. In this work, we provide examples of iterative algorithms that utilize the reciprocity of wireless networks to achieve interference alignment with only local channel knowledge at each node. These algorithms also provide numerical insights into the feasibility of interference alignment that are not yet available in theory.

Amygdala activity at encoding correlated with long-term, free recall of emotional information.

Abstract: Positron emission tomography of cerebral glucose metabolism in adult human subjects was used to investigate amygdaloid complex (AC) activity associated with the storage of long-term memory for emotionally arousing events. Subjects viewed two videos (one in each of two separate positron emission tomography sessions, separated by 3-7 days) consisting either of 12 emotionally arousing film clips ("E" film session) or of 12 relatively emotionally neutral film clips ("N" film session), and rated their emotional reaction to each film clip immediately after viewing it. Three weeks after the second session, memory for the videos was assessed in a free recall test. As expected, the subjects' average emotional reaction to the E films was higher than that for the N films. In addition, the subjects recalled significantly more E films than N films. Glucose metabolic rate of the right AC while viewing the E films was highly correlated with the number of E films recalled. AC activity was not significantly correlated with the number of N films recalled. The findings support the view derived from both animal and human investigations that the AC is selectively involved with the formation of enhanced long-term memory associated with emotionally arousing events.