Radiation of the Inner Horizon of the Reissner-Nordstr\"om Black Hole

Despite of over thirty years of research of the black hole thermodynamics our understanding of the possible role played by the inner horizons of Reissner-Nordstr\"om and Kerr-Newman black holes in black hole thermodynamics is still somewhat incomplete: There are derivations which imply that the temperature of the inner horizon is negative and it is not quite clear what this means. Motivated by this problem we perform a detailed analysis of the radiation emitted by the inner horizon of the Reissner-Nordstr\"om black hole. As a result we find that in a maximally extended Reissner-Nordstr\"om spacetime virtual particle-antiparticle pairs are created at the inner horizon of the Reissner-Nordstr\"om black hole such that real particles with positive energy and temperature are emitted towards the singularity from the inner horizon and, as a consequence, antiparticles with negative energy are radiated away from the singularity through the inner horizon. We show that these antiparticles will come out from the white hole horizon in the maximally extended Reissner-Nordstr\"om spacetime, at least when the hole is near extremality. The energy spectrum of the antiparticles leads to a positive temperature for the white hole horizon. In other words, our analysis predicts that in addition to the radiation effects of black hole horizons, also the white hole horizon radiates. The black hole radiation is caused by the quantum effects at the outer horizon, whereas the white hole radiation is caused by the quantum effects at the inner horizon of the Reissner-Nordstr\"om black hole.Comment: 22 pages, 6 figures. References added, discussion slightly expanded in Secs. I and V. To appear in IJMP

Jaynes Cummings treatment of superconducting resonators with dielectric loss due to two-level systems

We perform a quantum mechanical analysis of superconducting resonators subject to dielectric loss arising from charged two-level systems. We present numerical and analytical descriptions of the dynamics of energy decay from the resonator within the Jaynes-Cummings model. Our analysis allows us to distinguish the strong and weak coupling regimes of the model and to describe within each regime cases where the two-level system is unsaturated or saturated. We find that the quantum theory agrees with the classical model for weak coupling. However, for strong coupling the quantum theory predicts lower loss than the classical theory in the unsaturated regime. Also, in contrast to the classical theory, the photon number at which saturation occurs in the strong coupling quantum theory is independent of the coupling between the resonator and the two-level system.Comment: 9 pages, 8 figure

The Prevalence and Risk Factors of GERD Among Indonesian Medical Doctors

Background: Based on our knowledge, the study of gastrointestinal reflux disease (GERD) among certain profession has never been conducted. The aim of this study is to determine the prevalence and risk factors of GERD among Indonesian doctors. Methods: A consecutive study involving 515 doctors was conducted in October 2015. The GerdQ score was used to the diagnosis of GERD and determined its impact on daily life. All possible risk factors were also analysed. Results: A total of 515 subjects completed the questionnaire. The mean age of them was 41.37 ± 11.92 years old. Fifty-five percent of them were male and 60.6% general practitioners. The prevalence of GERD was 27.4% of which 21.0% was had GERD with low impact on daily life, and 6.4% was GERD with high impact on daily life. The statistically significant risk factors of GERD was found in age >50 y.o (p = 0.002; OR = 2.054), BMI >30 kg/m2 (p = 0.016; OR = 2.53), and smokers (p = 0.031; OR = 1.982). Sex and education level were not found significant statistically as the risk factors of GERD. Conclusions: The prevalence of GERD among Indonesian physician was 27.4%. We found that age over 50 y.o, obesity and smoking habit were the risk factors of GERD in Indonesian doctors.&nbsp

Longitudinal Association between Video Game Use and Physical, Mental, and Social Health Outcomes in Young Adults in the United States

Background: Increasing adolescent engagement in video game use and its associations with public health outcomes has been a controversial topic over the last several decades, with studies conducted in the United States only managing to produce contradictory results. This dissertation explores the statistical associations between video game use in adolescents and various physical, mental and social health outcomes as they develop into adulthood in the United States. Methodology: Secondary data analysis was conducted, guided by Life Course Theory, utilizing publicly available data from the National Longitudinal Study of Adolescent to Adult Health. Results: Video game use during adolescence was significantly associated with the risk for development of metabolic syndrome in adulthood (p =.034). No significant association was found between video game use at any time point and increased measures of violence and aggression. A significant association was found between weekly hours of video game use and sleep problems (p = .002), depression (p = .006), anxiety / panic attacks (p = .021), and marijuana use (p = .001). No significant association was found between video game use and ADHD/ADD and drug use excluding marijuana. Conclusion: This dissertation highlights several risks and benefits associated with engaging in video game use. These findings help to inform future public health practice and research. In moderation video game use was shown to have prosocial and positive effects on youth development as they grow into adulthood. However, when video game use exceeded 30 hours or more per week, detrimental effects began to emerge, including an increased risk for the development of metabolic syndrome, sleep problems, depression, anxiety, and marijuana use. Demographic variables such as gender and race / ethnicity and Life Course Theory variables of education and marital status were shown to have greater associations across all health outcomes than video game use at any time point. Recommendations for future research on the topic are discussed, including further investigation of the more significant findings and replication of the statistical analyses using Add Health wave V data once available

Orchestration : the movement and vocal behavior of free-ranging Norwegian killer whales (Orcinus orca)

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2008Studying the social and cultural transmission of behavior among animals helps to identify patterns of interaction and information content flowing between individuals. Killer whales are likely to acquire traits culturally based on their population-specific feeding behaviors and group-distinctive vocal repertoires. I used digital tags to explore the contributions of individual Norwegian killer whales to group carousel feeding and the relationships between vocal and non-vocal activity. Periods of tail slapping to incapacitate herring during feeding were characterized by elevated movement variability, heightened vocal activity and call types containing additional orientation cues. Tail slaps produced by tagged animals were identified using a rapid pitch change and occurred primarily within 20m of the surface. Two simultaneously tagged animals maneuvered similarly when tail slapping within 60s of one another, indicating that the position and composition of the herring ball influenced their behavior. Two types of behavioral sequence preceding the tight circling of carousel feeding were apparent. First, the animals engaged in periods of directional swimming. They were silent in 2 of 3 instances, suggesting they may have located other foraging groups by eavesdropping. Second, tagged animals made broad horizontal loops as they dove in a manner consistent with corralling. All 4 of these occasions were accompanied by vocal activity, indicating that this and tail slapping may benefit from social communication. No significant relationship between the call types and the actual movement measurements was found. Killer whale vocalizations traditionally have been classified into discrete call types. Using human speech processing techniques, I considered that calls are alternatively comprised of shared segments that can be recombined to form the stereotyped and variable repertoire. In a classification experiment, the characterization of calls using the whole call, a set of unshared segments, or a set of shared segments yielded equivalent performance. The shared segments required less information to parse the same vocalizations, suggesting a more parsimonious system of representation. This closer examination of the movements and vocalizations of Norwegian killer whales, combined with future work on ontogeny and transmission, will inform our understanding of whether and how culture plays a role in achieving population-specific behaviors in this species.Funding sources: The Ocean Life Institute at WHOI and the National Geographic Society, the National Defense Science and Engineering Graduate Fellowship, a National Science Foundation Graduate Fellowship, the Academic Programs Office at WHOI and Dennis McLaughlin at MIT