162 research outputs found

    Unitarily invariant norm inequalities for operators

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    We present several operator and norm inequalities for Hilbert space operators. In particular, we prove that if A1,A2,...,AnB(H)A_{1},A_{2},...,A_{n}\in {\mathbb B}({\mathscr H}), then A1A2+A2A3+...+AnA1i=1nAiAi,|||A_{1}A_{2}^{*}+A_{2}A_{3}^{*}+...+A_{n}A_{1}^{*}|||\leq|||\sum_{i=1}^{n}A_{i}A_{i}^{*}|||, for all unitarily invariant norms. We also show that if A1,A2,A3,A4A_{1},A_{2},A_{3},A_{4} are projections in B(H){\mathbb B}({\mathscr H}), then &&|||(\sum_{i=1}^{4}(-1)^{i+1}A_{i})\oplus0\oplus0\oplus0|||&\leq&|||(A_{1}+|A_{3}A_{1}|)\oplus (A_{2}+|A_{4}A_{2}|)\oplus(A_{3}+|A_{1}A_{3}|)\oplus(A_{4}+|A_{2}A_{4}|)||| for any unitarily invariant norm.Comment: 10 pages, Accepted pape

    Childhood trauma: a risk for major depression in patients with psoriasis

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    INTRODUCTION: A history of childhood trauma is an important determinant for understanding the development of psychiatric and physical disorders. The chronic inflammatory disease, psoriasis, has been reported to be affected by childhood psychological stressors. Early life stress is also a well-known contributor to major depression. The current study aims to clarify a possible association between levels and types of childhood trauma with psoriasis severity and major depression. METHOD: Sixty-four patients diagnosed with mild-to-severe psoriasis (male = 27, mean age = 52.51 ± 14.72 years and female = 37, mean age = 42.76 ± 14.45 years, age range = 21–77) were admitted to our study between April 2014 and September 2014. For the diagnosis of psoriasis, the single most recently developed lesion was examined dermoscopically and histopathologically. We evaluated the history of childhood trauma with the Childhood Trauma Questionnaire and diagnosis of major depression with the Mini International Neuropsychiatric Interview (MINI 5.0.0 current). The participants were scanned for their severity of psoriasis with Psoriasis Area and Severity Index 75 (PASI 75). Initially, the data were checked for normality using Kolmogorov–Smirnov/Shapiro–Wilk’s tests, histograms, and probability plots. Because normality of the data could not be assumed, we evaluated childhood trauma subscales and psoriasis by running Kendell’s tau-b correlation coefficients for bivariate comparisons. Mann–Whitney U test was conducted to assess the differences in childhood trauma severity of each subscale between two groups of depressed and nondepressed patients with psoriasis. Ultimately, we ran chi-square analysis to evaluate the association between gender and depression. RESULTS: Emotional (0.325), physical (0.614), sexual (0.963) abuse, and emotional (0.331) neglect were positively correlated with higher severity of psoriasis (p < .01). Subsequently, emotional (U = 372, p = .43), physical (U = 387, p = .049), sexual (U = 297, p = .0005) abuse, emotional (U = 299.5, p = .001), and physical U = 372, p = .031) neglect were significantly higher in psoriasis patients with depression compared to non-depressed (p < .05). CONCLUSION: The findings of the current study underline the relationship between childhood trauma and major depression, as well as childhood trauma and psoriasis. The increased level of emotional, physical, sexual abuse, and emotional neglect was linked to elevated severity of psoriasis. Likewise, all childhood trauma subtypes appeared to be more severe in the group of psoriasis patients with major depression. Investigation of childhood traumatic experiences, and major depression in individuals with psoriasis, the screening of depressed patients for psoriasis, and the cross-referencing of the outcome can be expected to provide remarkable findings, new approaches for diagnosis and treatment, as well as implications for promulgating new legislation

    Parametric architecture in it’s second phase of evolution

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    This paper seeks to illustrate the evolution history of Parametric Architecture and describe the reasons why parametric architecture, in its second phase of evolution, called “Parametricism 2.0”, is showing promising abilities in solving more and more intricate socio-environmental problems. In this sense, paper discusses that mentioned school of architecture can be used in several fields other than mere form finding and geometrical coding. Current article studies the history of parametric architecture by finding the root of its name, reviewing its early designs and discussing the work of two of its precursors; then moves on to examine the current situation of the style and defines the word: Parametricism. Paper continues to study the vistas ahead by presenting techniques that empower Parametricism and concludes its discussion by presenting a redefinition for Parametricism. Overall, the paper depicts how “Parametricism 2.0” intends to go back to solving socio-environmental problems; Problems that all the existing evolutionary and generative techniques were initially designed in order to answer them

    Investigating urban soundscapes of the COVID-19 lockdown: A predictive soundscape modeling approach

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    The unprecedented lockdowns resulting from COVID-19 in spring 2020 triggered changes in human activities in public spaces. A predictive modeling approach was developed to characterize the changes in the perception of the sound environment when people could not be surveyed. Building on a database of soundscape questionnaires (N = 1,136) and binaural recordings (N = 687) collected in 13 locations across London and Venice during 2019, new recordings (N = 571) were made in the same locations during the 2020 lockdowns. Using these 30-s-long recordings, linear multilevel models were developed to predict the soundscape pleasantness ( R2=0.85) and eventfulness ( R2=0.715) during the lockdown and compare the changes for each location. The performance was above average for comparable models. An online listening study also investigated the change in the sound sources within the spaces. Results indicate (1) human sounds were less dominant and natural sounds more dominant across all locations; (2) contextual information is important for predicting pleasantness but not for eventfulness; (3) perception shifted toward less eventful soundscapes and to more pleasant soundscapes for previously traffic-dominated locations but not for human- and natural-dominated locations. This study demonstrates the usefulness of predictive modeling and the importance of considering contextual information when discussing the impact of sound level reductions on the soundscape

    The Soundscape Indices (SSID) Protocol: A Method for Urban Soundscape Surveys—Questionnaires with Acoustical and Contextual Information

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    A protocol for characterizing urban soundscapes for use in the design of Soundscape Indices (SSID) and general urban research as implemented under the European Research Council (ERC)-funded SSID project is described in detail. The protocol consists of two stages: (1) a Recording Stage to collect audio-visual recordings for further analysis and for use in laboratory experiments, and (2) a Questionnaire Stage to collect in situ soundscape assessments via a questionnaire method paired with acoustic data collection. Key adjustments and improvements to previous methodologies for soundscape characterization have been made to enable the collation of data gathered from research groups around the world. The data collected under this protocol will form a large-scale, international soundscape database

    The squared Commutativity degree of dihedral groups

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    The commutativity degree of a finite group is the probability that a random pair of elements in the group commute. Furthermore, the n-th power commutativity degree of a group is a generalization of the commutativity degree of a group which is defined as the probability that the n-th power of a random pair of elements in the group commute. In this paper, the n-th power commutativity degree for some dihedral groups is computed for the case n equal to 2, called the squared commutativity degree
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