Algorithms vs. Human Nature: A Tale of Selective Exposure

The public’s turn towards news websites and social media for news consumption has sparked anxiety over echo chambers, avoidance of opinion-challenging content, and potentially fragmentation and polarization among sociopolitical groups. Algorithms have specifically been blamed for increasing the ease of filtering out counter-attitudinal online content and potentially exacerbating selective exposure tendencies. However, longstanding classic psychological research has demonstrated the ubiquitous phenomenon of cognitive dissonance and selective exposure far before the internet became the primary tool for news consumption. Research investigating how algorithms directly influence online approach and avoidance behavior is unfortunately scarce. This dissertation work aimed to analyze the impact of an algorithm system during online information consumption on selective exposure behavior. Participants were randomly assigned to one of three conditions: a neutral condition where presented articles are balanced in attitudinal valence; an algorithm condition where presented articles update to match previous selection behavior; and a motivated condition where participants are encouraged to explore dissimilar viewpoints. Overall, a-priori hypotheses were not supported, and condition had virtually no effect on dependent variables, including selective exposure tendency. However, results provide an in-depth look into perceptual and behavioral processes of highly polarized individuals during the information-seeking process

Calling Out the Trolls: Responses to Witnessing Use of the “Troll” Label as a Defense in an Online Group Context

Although the term “troll” has existed since the 1980s, its meaning has shifted in recent years as social media use has increased. People provide contrasting and imprecise definitions for what constitutes “trolling,” and often apply the term subjectively to describe online discussants who are uncivil, who are deviant, and who and present counter-attitudinal opinions. Exposure to deviance, counter-attitudinal information, and incivility often leads to unwanted psychological effects. In theory, labeling an uncivil, counter-attitudinal deviant as a “troll” proposes that their intention is to disrupt the conversation and upset other discussants, which provides a reason for why incivility is used, and diminishes the threat of counter-attitudinal exposure. Participants were placed into an online discussion about transgender identities; while participants believed they were discussing with real people, they were actually interacting with a scripted computer program. All discussion comments were pro-attitudinal, save one. A 2 X 3 between-subjects design was employed to examine the effects of the civility of the counter-attitudinal comment (civil vs. uncivil) and the label used against this counter-attitudinal discussant (no label vs. rude label vs. troll label). Incivility exposure overall produced higher ratings of anger, attitude certainty, intentions to participate, and identification with the discussion group. The rude label overall decreased attitude certainty, while the troll label overall increased identification with being a person with their pre-existing attitude. In the uncivil condition, participants were marginally more willing to participate again when the troll label was applied, when compared to the two other label conditions. The intersecting influences of gender, pre-existing attitudes, and suspicions about the deception used are discussed

Survey of Community Pharmacy Customers’ Medication Storage and Disposal Methods

Many people store medications in bathrooms, which provide a moist, humid environment that speeds up the breakdown process of medications. The proper way to store medicines is in a cool, dry place out of the reach of children. Every year medications are also disposed of improperly presenting a risk to both humans and the environment. About one-third of all sold medications are unused. The most common ways patients dispose of medications in the United States are flushing down the toilet or sink, and throwing them away. Because of this pharmaceuticals have been found in groundwater, and drinking water proving hazardous to both humans and ecosystems. In Congress today, both the Drug Free Water Act and the Safe Drug Disposal Act have been proposed to limit the disposal of pharmaceuticals in sewage systems, and provide the means of controlled substance disposal through take-back programs. In February 2007 the White House Office of National Drug Control Policy (ONDCP) established guidelines for the disposal of prescription medications. ONDCP guidelines are: take unused, unneeded or expired medications out of the original container, mix with an undesirable substance (such as coffee grounds), securely seal in impermeable containers, such as sealable bags, and throw into the trash. ONDCP recommends only flushing if the label or patient information specifies to do so. Taking advantage of community pharmaceutical take-back programs is highly encouraged

Theory of Pump Depletion and Spike Formation in Stimulated Raman Scattering

By using the inverse spectral transform, the SRS equations are solved and the explicit output data is given for arbitrary laser pump and Stokes seed profiles injected on a vacuum of optical phonons. For long duration laser pulses, this solution is modified such as to take into account the damping rate of the optical phonon wave. This model is used to interprete the experiments of Druhl, Wenzel and Carlsten (Phys. Rev. Lett., (1983) vol. 51, p. 1171), in particular the creation of a spike of (anomalous) pump radiation. The related nonlinear Fourier spectrum does not contain discrete eigenvalue, hence this Raman spike is not a soliton.Comment: LaTex file, includes two figures in LaTex format, 9 page

Sleep spindle deficits in antipsychotic-naïve early course schizophrenia and in non-psychotic first-degree relatives

Introduction: Chronic medicated patients with schizophrenia have marked reductions in sleep spindle activity and a correlated deficit in sleep-dependent memory consolidation. Using archival data, we investigated whether antipsychotic-naïve early course patients with schizophrenia and young non-psychotic first-degree relatives of patients with schizophrenia also show reduced sleep spindle activity and whether spindle activity correlates with cognitive function and symptoms. Method: Sleep spindles during Stage 2 sleep were compared in antipsychotic-naïve adults newly diagnosed with psychosis, young non-psychotic first-degree relatives of schizophrenia patients and two samples of healthy controls matched to the patients and relatives. The relations of spindle parameters with cognitive measures and symptom ratings were examined. Results: Early course schizophrenia patients showed significantly reduced spindle activity relative to healthy controls and to early course patients with other psychotic disorders. Relatives of schizophrenia patients also showed reduced spindle activity compared with controls. Reduced spindle activity correlated with measures of executive function in early course patients, positive symptoms in schizophrenia and IQ estimates across groups. Conclusions: Like chronic medicated schizophrenia patients, antipsychotic-naïve early course schizophrenia patients and young non-psychotic relatives of individuals with schizophrenia have reduced sleep spindle activity. These findings indicate that the spindle deficit is not an antipsychotic side-effect or a general feature of psychosis. Instead, the spindle deficit may predate the onset of schizophrenia, persist throughout its course and be an endophenotype that contributes to cognitive dysfunction

Translational profiling of hypocretin neurons identifies candidate molecules for sleep regulation

Hypocretin (orexin; Hcrt)-containing neurons of the hypothalamus are essential for the normal regulation of sleep and wake behaviors and have been implicated in feeding, anxiety, depression, and reward. The absence of these neurons causes narcolepsy in humans and model organisms. However, little is known about the molecular phenotype of these cells; previous attempts at comprehensive profiling had only limited sensitivity or were inaccurate. We generated a Hcrt translating ribosome affinity purification (bacTRAP) line for comprehensive translational profiling of all ribosome-bound transcripts in these neurons in vivo. From this profile, we identified >6000 transcripts detectably expressed above background and 188 transcripts that are highly enriched in these neurons, including all known markers of the cells. Blinded analysis of in situ hybridization databases suggests that ∼60% of these are expressed in a Hcrt marker-like pattern. Fifteen of these were confirmed with double labeling and microscopy, including the transcription factor Lhx9. Ablation of this gene results in a >30% loss specifically of Hcrt neurons, without a general disruption of hypothalamic development. Polysomnography and activity monitoring revealed a profound hypersomnolence in these mice. These data provide an in-depth and accurate profile of Hcrt neuron gene expression and suggest that Lhx9 may be important for specification or survival of a subset of these cells

The role of HO_x in super- and subsonic aircraft exhaust plumes

The generation of sulfuric acid aerosols in aircraft exhaust has emerged as a critical issue in determining the impact of supersonic aircraft on stratospheric ozone. It has long been held that the first step in the mechanism of aerosol formation is the oxidation of SO_(2) emitted from the engine by OH in the exhaust plume. We report in situ measurements of OH and HO_(2) in the exhaust plumes of a supersonic (Air France Concorde) and a subsonic (NASA ER-2) aircraft in the lower stratosphere. These measurements imply that reactions with OH are responsible for oxidizing only a small fraction of SO_(2) (2%), and thus cannot explain the large number of particles observed in the exhaust wake of the Concorde