University of North Florida

About: University of North Florida is a education organization based out in Jacksonville, Florida, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 2815 authors who have published 5506 publications receiving 101336 citations. The organization is also known as: UNF.

Plasmonic nanorod metamaterials for biosensing.

Abstract: Label-free plasmonic biosensors rely either on surface plasmon polaritons or on localized surface plasmons on continuous or nanostructured noble-metal surfaces to detect molecular-binding events. Despite undisputed advantages, including spectral tunability, strong enhancement of the local electric field and much better adaptability to modern nanobiotechnology architectures, localized plasmons demonstrate orders of magnitude lower sensitivity compared with their guided counterparts. Here, we demonstrate an improvement in biosensing technology using a plasmonic metamaterial that is capable of supporting a guided mode in a porous nanorod layer. Benefiting from a substantial overlap between the probing field and the active biological substance incorporated between the nanorods and a strong plasmon-mediated energy confinement inside the layer, this metamaterial provides an enhanced sensitivity to refractive-index variations of the medium between the rods (more than 30,000 nm per refractive-index unit). We demonstrate the feasibility of our approach using a standard streptavidin-biotin affinity model and record considerable improvement in the detection limit of small analytes compared with conventional label-free plasmonic devices.

A spelling device for the paralysed

Abstract: When Jean-Dominique Bauby suffered from a cortico-subcortical stroke that led to complete paralysis with totally intact sensory and cognitive functions, he described his experience in The Diving-Bell and the Butterfly1 as “something like a giant invisible diving-bell holds my whole body prisoner”. This horrifying condition also occurs as a consequence of a progressive neurological disease, amyotrophic lateral sclerosis, which involves progressive degeneration of all the motor neurons of the somatic motor system. These ‘locked-in’ patients ultimately become unable to express themselves and to communicate even their most basic wishes or desires, as they can no longer control their muscles to activate communication devices. We have developed a new means of communication for the completely paralysed that uses slow cortical potentials (SCPs) of the electro-encephalogram to drive an electronic spelling device.

Searching for dark matter annihilation from Milky Way dwarf spheroidal galaxies with six years of Fermi Large Area Telescope data

Abstract: The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on γ-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new Pass8 event-level analysis. None of the dSphs are significantly detected in γ rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass ≲100 GeV annihilating via quark and τ-lepton channels.

One hundred years of social psychology quantitatively described

Abstract: This article compiles results from a century of social psychological research, more than 25,000 studies of 8 million people. A large number of social psychological conclusions are listed alongside meta-analytic information about the magnitude and variability of the corresponding effects. References to 322 meta-analyses of social psychological phenomena are presented, as well as statistical effect-size summaries. Analyses reveal that social psychological effects typically yield a value of r equal to .21 and that, in the typical research literature, effects vary from study to study in ways that produce a standard deviation in r of .15. Uses, limitations, and implications of this large-scale compilation are noted. In 1898 Norman Triplett published an early experiment in social psychology, about an effect of the presence of others on task performance. In the 100 years since Triplett’s investigation, many social psychological effects have been documented. The current article summarizes the best established of these findings, with data from more than 25,000 research studies and 8 million people. Our goal is to quantify the magnitude and variability of social psychological effects. We begin by considering previous summaries of social psychology, note some unresolved issues, and review developments that permit a century of scholarly work to be quantitatively described. For present purposes, we follow Manstead and Hewstone (1995) in regarding social psychology as the study of “the reciprocal influence of the individual and his or her social context” (p. 588).