Quantum Field Theory of Meson Mixing

We have developed a quantum field theoretic framework for scalar and pseudoscalar meson mixing and oscillations in time. The unitary inequivalence of the Fock space of base (unmixed) eigenstates and the physical mixed eigenstates is proven and shown to lead to a rich condensate structure. This is exploited to develop formulas for two flavor boson oscillations in systems of arbitrary boson occupation number. The mixing and oscillation can be understood in terms of vacuum condensate which interacts with the bare particles to induce non-trivial effects. We apply these formulas to analyze the mixing of $\eta$ with $\eta'$ and comment on the $K_L K_S$ system. In addition, we consider the mixing of boson coherent states, which may have future applications in the construction of meson lasers.Comment: 12 pages, 3 figures; Eqs.(10-12) corrected, leading to new physical insights; added paragraph under Eq.(24) explaining physical interpretation of mixing in terms of vacuum condensation; references added and minor typo correcte

Building an Argument for the Use of Science Fiction in HCI Education

Science fiction literature, comics, cartoons and, in particular, audio-visual materials, such as science fiction movies and shows, can be a valuable addition in Human-computer interaction (HCI) Education. In this paper, we present an overview of research relative to future directions in HCI Education, distinct crossings of science fiction in HCI and Computer Science teaching and the Framework for 21st Century Learning. Next, we provide examples where science fiction can add to the future of HCI Education. In particular, we argue herein first that science fiction, as tangible and intangible cultural artifact, can serve as a trigger for creativity and innovation and thus, support us in exploring the design space. Second, science fiction, as a means to analyze yet-to-come HCI technologies, can assist us in developing an open-minded and reflective dialogue about technological futures, thus creating a singular base for critical thinking and problem solving. Provided that one is cognizant of its potential and limitations, we reason that science fiction can be a meaningful extension of selected aspects of HCI curricula and research.Comment: 6 pages, 1 table, IHSI 2019 accepted submissio

On the Spectrum of Field Quadratures for a Finite Number of Photons

The spectrum and eigenstates of any field quadrature operator restricted to a finite number $N$ of photons are studied, in terms of the Hermite polynomials. By (naturally) defining \textit{approximate} eigenstates, which represent highly localized wavefunctions with up to $N$ photons, one can arrive at an appropriate notion of limit for the spectrum of the quadrature as $N$ goes to infinity, in the sense that the limit coincides with the spectrum of the infinite-dimensional quadrature operator. In particular, this notion allows the spectra of truncated phase operators to tend to the complete unit circle, as one would expect. A regular structure for the zeros of the Christoffel-Darboux kernel is also shown.Comment: 16 pages, 11 figure

Contracts in Practice

Contracts are a form of lightweight formal specification embedded in the program text. Being executable parts of the code, they encourage programmers to devote proper attention to specifications, and help maintain consistency between specification and implementation as the program evolves. The present study investigates how contracts are used in the practice of software development. Based on an extensive empirical analysis of 21 contract-equipped Eiffel, C#, and Java projects totaling more than 260 million lines of code over 7700 revisions, it explores, among other questions: 1) which kinds of contract elements (preconditions, postconditions, class invariants) are used more often; 2) how contracts evolve over time; 3) the relationship between implementation changes and contract changes; and 4) the role of inheritance in the process. It has found, among other results, that: the percentage of program elements that include contracts is above 33% for most projects and tends to be stable over time; there is no strong preference for a certain type of contract element; contracts are quite stable compared to implementations; and inheritance does not significantly affect qualitative trends of contract usage

Isoscalar resonances with J^{PC}=1^{--} in e^+e^-annihilation

The analysis of the vector isoscalar excitations in the energy range between 1 and 2 GeV of the $e^+e^-$ annihilation is presented for the final states $\pi^+\pi^-\pi^0$, $\omega\pi^+\pi^-$, $K^+K^-$, $K^0_SK^\pm\pi^\mp$ and $K^{\ast0}K^-\pi^++ c.c$. The effects of both the resonance mixing and the successive opening of multiparticle channels, with the energy dependent partial widths, are taken into account. The work extends our previous analysis hep-ph/9609216 of the vector isovector excitations and is aimed to compare the existing data with the predictions of the $q\bar q$ model. It is shown that this hypothesis does not contradict the data.Comment: 16 pages, revtex, 6 ps figures. Clarifying remarks, a table, and references are added. Accepted in Phys. Rev.

Effect of External Boundary Layer on Performance of Axisymmetric Inlet at Mach Numbers of 3.0 and 2.5

The effect of an external boundary layer on the performance of an axisymmetric external-internal-compression inlet was evaluated at Mach numbers of 3.0 and 2.5 and Reynolds numbers from 2.2 to 0.5 x 10(exp 6) per foot. The inlet was tested at locations up to two-thirds of the way into the 1.7- and 9.0-inch boundary layers generated by a flat plate and the tunnel floor, respectively. The inlet could be readily started at all conditions tested, including those where the boundary layer was separated upstream of the inlet by the various shock systems during the restart cycle. Although the inlet performance decreased with increasing immersion into the boundary layer at both Mach numbers, the inlet was more sensitive to boundary-layer ingestion at the design Mach number of 3.0

Comorbidity and Quality of Life in Adults with Hair Pulling Disorder

Hair pulling disorder (HPD; trichotillomania) is thought to be associated with significant psychiatric comorbidity and functional impairment. However, few methodologically rigorous studies of HPD have been conducted, rendering such conclusions tenuous. The following study examined comorbidity and psychosocial functioning in a well-characterized sample of adults with HPD (N=85) who met DSM-IV criteria, had at least moderate hair pulling severity, and participated in a clinical trial. Results revealed that 38.8% of individuals with HPD had another current psychiatric diagnosis and 78.8% had another lifetime (present and/or past) psychiatric diagnosis. Specifically, HPD showed substantial overlap with depressive, anxiety, addictive, and other body-focused repetitive behavior disorders. The relationships between certain comorbidity patterns, hair pulling severity, current mood and anxiety symptoms, and quality of life were also examined. Results showed that current depressive symptoms were the only predictor of quality of life deficits. Implications of these findings for the conceptualization and treatment of HPD are discussed

Factor Analysis of the Milwaukee Inventory for Subtypes of Trichotillomania-Adult Version

The Milwaukee Inventory for Subtypes of Trichotillomania-Adult Version (MIST-A; Flessner et al., 2008) measures the degree to which hair pulling in Trichotillomania (TTM) can be described as “automatic” (i.e., done without awareness and unrelated to affective states) and/or “focused” (i.e., done with awareness and to regulate affective states). Despite preliminary evidence in support of the psychometric properties of the MIST-A, emerging research suggests the original factor structure may not optimally capture TTM phenomenology. Using data from a treatment-seeking TTM sample, the current study examined the factor structure of the MIST-A via exploratory factor analysis. The resulting two factor solution suggested the MIST-A consists of a 5-item “awareness of pulling” factor that measures the degree to which pulling is done with awareness and an 8-item “internal-regulated pulling” factor that measures the degree to which pulling is done to regulate internal stimuli (e.g., emotions, cognitions, and urges). Correlational analyses provided preliminary evidence for the validity of these derived factors. Findings from this study challenge the notions of “automatic” and “focused” pulling styles and suggest that researchers should continue to explore TTM subtypes

Clarifying the Relationship Between Trichotillomania and Anxiety

Although research has consistently linked unidimensional anxiety with Trichotillomania (TTM) severity, the relationships between TTM severity and anxiety dimensions (e.g., cognitive and somatic anxiety) are unknown. This knowledge gap limits current TTM conceptualization and treatment. The present study examined these relationships with data collected from ninety-one adults who participated in a randomized clinical trial for TTM treatment. Based on prior research, it was hypothesized that TTM severity would be related to the cognitive anxiety dimension and that psychological inflexibility would mediate the association. Hypotheses were not made regarding the relationship between TTM severity and somatic anxiety. Regression analyses indicated that only cognitive dimensions of anxiety predicted TTM severity and that psychological inflexibility mediated this relationship. Implications for the conceptualization and treatment of TTM are discussed

Photographic Assessment of Change in Trichotillomania: Psychometric Properties and Variables Influencing Interpretation

Although photographic assessment has been found to be reliable in assessing hair loss in Trichotillomania, the validity of this method is unclear, particularly for gauging progress in treatment. The current study evaluated the psychometric properties of photographic assessment of change in Trichotillomania. Photographs showing hair loss of adults with Trichotillomania were taken before and after participating in a clinical trial for the condition. Undergraduate college students (N = 211) rated treatment response according to the photos, and additional archival data on hair pulling severity and psychosocial health were retrieved from the clinical trial. Photographic assessment of change was found to possess fair reliability (ICC = 0.53), acceptable criterion validity (r = 0.51), good concurrent validity (r = 0.30–0.36), and excellent incremental validity (ΔR2 = 8.67, p \u3c 0.01). In addition, photographic measures were significantly correlated with change in quality of life (r = 0.42), and thus could be considered an index of the social validity of Trichotillomania treatment. Gender of the photo rater and pulling topography affected the criterion validity of photographic assessment (partial η2 = 0.05–0.11). Recommendations for improving photographic assessment and future directions for hair pulling research are discussed