6,765 research outputs found

    Advancing Peacebuilding from the Ground up

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    For many years, scholars and practitioners have been struggling with problems of local ownership in international organizations-led peacebuilding. Despite the discourse surrounding giving ownership to local communities, top-down approaches prevail in practice and often lead to counterproductive outcomes. Ethnographic fieldwork has proven that international organizsations could achieve a better understanding of local experiential perspectives on conflict and peace. Here, we point to key features of local peace and suggest how international organizations could better incorporate peaceful local agency, cope with power imbalances and advance strategies for peacebuilding from the ground up

    Bulletin No. 30: Native Shrubs for Landscaping

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    Parameterized Inapproximability of Target Set Selection and Generalizations

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    In this paper, we consider the Target Set Selection problem: given a graph and a threshold value thr(v)thr(v) for any vertex vv of the graph, find a minimum size vertex-subset to "activate" s.t. all the vertices of the graph are activated at the end of the propagation process. A vertex vv is activated during the propagation process if at least thr(v)thr(v) of its neighbors are activated. This problem models several practical issues like faults in distributed networks or word-to-mouth recommendations in social networks. We show that for any functions ff and ρ\rho this problem cannot be approximated within a factor of ρ(k)\rho(k) in f(k)nO(1)f(k) \cdot n^{O(1)} time, unless FPT = W[P], even for restricted thresholds (namely constant and majority thresholds). We also study the cardinality constraint maximization and minimization versions of the problem for which we prove similar hardness results

    Sommerfeld's quantum condition of action and the spectra of Schwarzschild black hole

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    If the situation of quantum gravity nowadays is nearly the same as that of the quantum mechanics in it's early time of Bohr and Sommerfeld, then a first step study of the quantum gravity from Sommerfeld's quantum condition of action might be helpful. In this short paper the spectra of Schwarzschild black hole(SBH) in quasi-classical approach of quantum mechanics is given. We find the quantum of area, the quantum of entropy and the Hawking evaporation will cease as the black hole reaches its ground state.Comment: 7 pages, no figures, submitted to Classical and Quantum Gravit

    Chandra Observations of Extended X-ray Emission in Arp 220

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    We resolve the extended X-ray emission from the prototypical ultraluminous infrared galaxy Arp 220. Extended, faint edge-brightened, soft X-ray lobes outside the optical galaxy are observed to a distance of 10 to 15 kpc on each side of the nuclear region. Bright plumes inside the optical isophotes coincide with the optical line emission and extend 11 kpc from end to end across the nucleus. The data for the plumes cannot be fit by a single temperature plasma, and display a range of temperatures from 0.2 to 1 keV. The plumes emerge from bright, diffuse circumnuclear emission in the inner 3 kpc centered on the Halpha peak, which is displaced from the radio nuclei. There is a close morphological correspondence between the Halpha and soft X-ray emission on all spatial scales. We interpret the plumes as a starburst-driven superwind, and discuss two interpretations of the emission from the lobes in the context of simulations of the merger dynamics of Arp 220.Comment: Accepted for publication in ApJ; see also astro-ph/0208477 (Paper 1

    Compilation of extended recursion in call-by-value functional languages

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    This paper formalizes and proves correct a compilation scheme for mutually-recursive definitions in call-by-value functional languages. This scheme supports a wider range of recursive definitions than previous methods. We formalize our technique as a translation scheme to a lambda-calculus featuring in-place update of memory blocks, and prove the translation to be correct.Comment: 62 pages, uses pi

    Later Credits: {R}esourceful Reasoning for the Later Modality

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    Effective temperature for black holes

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    The physical interpretation of black hole's quasinormal modes is fundamental for realizing unitary quantum gravity theory as black holes are considered theoretical laboratories for testing models of such an ultimate theory and their quasinormal modes are natural candidates for an interpretation in terms of quantum levels. The spectrum of black hole's quasinormal modes can be re-analysed by introducing a black hole's effective temperature which takes into account the fact that, as shown by Parikh and Wilczek, the radiation spectrum cannot be strictly thermal. This issue changes in a fundamental way the physical understanding of such a spectrum and enables a re-examination of various results in the literature which realizes important modifies on quantum physics of black holes. In particular, the formula of the horizon's area quantization and the number of quanta of area result modified becoming functions of the quantum "overtone" number n. Consequently, the famous formula of Bekenstein-Hawking entropy, its sub-leading corrections and the number of microstates are also modified. Black hole's entropy results a function of the quantum overtone number too. We emphasize that this is the first time that black hole's entropy is directly connected with a quantum number. Previous results in the literature are re-obtained in the limit n \to \infty.Comment: 10 pages,accepted for publication in Journal of High Energy Physics. Comments are welcom

    Highly Damped Quasinormal Modes of Kerr Black Holes: A Complete Numerical Investigation

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    We compute for the first time very highly damped quasinormal modes of the (rotating) Kerr black hole. Our numerical technique is based on a decoupling of the radial and angular equations, performed using a large-frequency expansion for the angular separation constant_{s}A_{l m}. This allows us to go much further in overtone number than ever before. We find that the real part of the quasinormal frequencies approaches a non-zero constant value which does not depend on the spin s of the perturbing field and on the angular index l: \omega_R=m\varpi(a). We numerically compute \varpi(a). Leading-order corrections to the asymptotic frequency are likely to be of order 1/\omega_I. The imaginary part grows without bound, the spacing between consecutive modes being a monotonic function of a.Comment: 5 pages, 3 figure

    Weight status and associated comorbidities in children and adults with Down syndrome, autism spectrum disorder and intellectual and developmental disabilities

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    This is the peer reviewed version of the following article: Ptomey, L. T., Walpitage, D. L., Mohseni, M., Dreyer Gillette, M. L., Davis, A. M., Forseth, B., Dean, E. E., and Waitman, L. R. (2020) Weight status and associated comorbidities in children and adults with Down syndrome, autism spectrum disorder and intellectual and developmental disabilities. Journal of Intellectual Disability Research, 64: 725– 737. https://doi.org/10.1111/jir.12767, which has been published in final form at https://doi.org/10.1111/jir.12767. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.Background Little is known about body weight status and the association between body weight and common comorbidities in children and adults with Down syndrome (DS), autism spectrum disorder (ASD) and other intellectual and developmental disabilities (IDDs). Methods Data were extracted from the University of Kansas Medical Center's Healthcare Enterprise Repository for Ontological Narration clinical integrated data repository. Measures included demographics (sex, age and race), disability diagnosis, comorbid health conditions, height, weight and body mass index percentiles (BMI%ile; <18 years of age) or BMI (≥18 years of age). Results Four hundred and sixty-eight individuals with DS (122 children and 346 adults), 1659 individuals with ASD (1073 children and 585 adults) and 604 individuals with other IDDs (152 children and 452 adults) were identified. A total of 47.0% (DS), 41.9% (ASD) and 33.5% (IDD) of children had overweight/obese (OW/OB), respectively. Children with DS were more likely to have OW/OB compared with children with IDD or ASD [odds ratio (OR) = 1.91, 95% confidence interval (CI): (1.49, 2.46); OR = 1.43, 95% CI: (1.19, 1.72)], respectively. A total of 81.1% (DS), 62.1% (ASD), and 62.4% (IDD) of adults were OW/OB, respectively. Adults with DS were more likely to have OW/OB compared with those with IDD [OR = 2.56, 95% CI: (2.16, 3.02)]. No significant differences were observed by race. In children with ASD, higher OW/OB was associated with significantly higher (compared with non-OW/OB) occurrence of sleep apnoea [OR = 2.94, 95% CI: (2.22, 3.89)], hypothyroidism [OR = 3.14, 95% CI: (2.17, 4.25)] and hypertension [OR = 4.11, 95% CI: (3.05, 5.54)]. In adults with DS, OW/OB was significantly associated with higher risk of sleep apnoea and type 2 diabetes [OR = 2.93, 95% CI: (2.10, 4.09); OR = 1.76, 95% CI: (1.11, 2.79) respectively]. Similarly, in adults with ASD and IDD, OW/OB was significantly associated with higher risk of sleep apnoea [OR = 3.39, 95% CI: (2.37, 4.85) and OR = 6.69, 95% CI: (4.43, 10.10)], type 2 diabetes [OR = 2.25, 95 % CI: (1.68, 3.01) and OR = 5.49, 95% CI: (3.96, 7.61)] and hypertension [OR = 3.55, 95% CI: (2.76, 4.57) and 3.97, 95% CI: (3.17, 4.97)]. Conclusion Findings suggest higher rates of OW/OB in individuals with DS compared with ASD and IDD. Given the increased risk of comorbidities associated with the increased risk of OW/OB, identification of effective interventions for this special population of individuals is critical
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