Image processing by Intensity-Dependent Spread (IDS)

As retinal illuminance is lowered, the human visual system integrates the effects of photon absorptions over larger areas and longer times. A theory of the process that might underlie these changes is called Intensity-Dependent Spread (IDS). Each input point gives rise to a pattern of excitation that spreads to a region of the total excitation it sees. The unique aspect of the theory is the assumption that, although the amplitude of the excitation pattern at its center increases with input illuminance, its width decreases in such a way that its volume remains constant. Application of this theory to image processing reveals that it displays a number of unexpected and potentially useful properties. Among them are edge enhancement and independence from scene illumination

Set-partition tableaux and representations of diagram algebras

The partition algebra is an associative algebra with a basis of set-partition diagrams and multiplication given by diagram concatenation. It contains as subalgebras a large class of diagram algebras including the Brauer, planar partition, rook monoid, rook-Brauer, Temperley-Lieb, Motzkin, planar rook monoid, and symmetric group algebras. We give a construction of the irreducible modules of these algebras in two isomorphic ways: first, as the span of symmetric diagrams on which the algebra acts by conjugation twisted with an irreducible symmetric group representation and, second, on a basis indexed by set-partition tableaux such that diagrams in the algebra act combinatorially on tableaux. The first representation is analogous to the Gelfand model and the second is a generalization of Young's natural representation of the symmetric group on standard tableaux. The methods of this paper work uniformly for the partition algebra and its diagram subalgebras. As an application, we express the characters of each of these algebras as nonnegative integer combinations of symmetric group characters whose coefficients count fixed points under conjugation

A randomised controlled pilot study: the effectiveness of narrative exposure therapy with adult survivors of the Sichuan earthquake

Background: Post-Traumatic Stress Disorder (PTSD) is a common psychological reaction after large-scale natural disasters. Given the number of people involved and shortage of resources in any major disaster, brief, pragmatic and easily trainable interventions are needed. The aim of this study is to evaluate the efficacy of Narrative Exposure Therapy (NET) as a short-term treatment for PTSD using Chinese earthquake survivors. Methods: A randomized waiting-list control pilot study was conducted between December 2009 and March 2010, at the site of the Sichuan earthquake in Beichuan County, China. Adult participants with newly diagnosed Post Traumatic Stress Disorder (PTSD) were randomly allocated to Narrative Exposure Therapy (NET) or a Waiting-List (WL) condition. The latter received NET treatment after a two-week waiting period. To compare the effectiveness of NET in traumatised earthquake survivors, both groups were assessed on PTSD symptoms, general mental health, anxiety and depression, social support, coping style and posttraumatic change before and after treatment and two months post treatment. Results: Adult participants (n=22) were randomly allocated to receive NET (n=11) or WL (n=11). Twenty two participants (11 in NET group, 11 in WL) were included in the analysis of primary outcomes. Compared with WL, NET showed significant reductions in PTSD symptoms, anxiety and depression, general mental stress and increased posttraumatic growth. The WL group later showed similar improvements after treatment. These changes remained stable for a two-month follow-up. Measures of social support and coping showed no stable effects. Conclusions: NET is effective in treating post-earthquake traumatic symptoms in adult Chinese earthquake survivors. The findings help advance current knowledge in the management of PTSD after natural disasters and inform future research. Larger sample sizes are needed to extend the present findings

Taking snapshots of the jet-ISM interplay with ALMA

We present an update of our on-going project to characterise the impact of radio jets on the ISM by tracing molecular gas at high spatial resolution using ALMA. The radio active galactic nuclei (AGN) studied show recently born radio jets. In this stage, the plasma jets can have the largest impact on the ISM, as also predicted by state-of-the-art simulations. The two targets have quite different ages, allowing us to get snapshots of the effects of radio jets as they grow. Interestingly, both also host powerful quasar emission. The largest mass outflow rate of molecular gas is found in a radio galaxy hosting a newly born radio jet emerging from an obscuring cocoon of gas and dust. Although the mass outflow rate is high (few hundred Msun/yr), the outflow is limited to the inner few hundred pc region. In a second object, the jet is larger (a few kpc) and is in a more advanced evolutionary phase. In this object, the distribution of the molecular gas is reminiscent of what is seen, on larger scales, in cool-core clusters hosting radio galaxies. Gas deviating from quiescent kinematics is not very prominent, limited only to the very inner region, and has a low mass outflow rate. Instead, on kpc scales, the radio lobes appear associated with depressions in the distribution of the molecular gas, suggesting they have broken out from the dense nuclear region. The AGN does not appear to be able at present to stop the star formation observed in this galaxy. These results suggest that the effects of the radio source start in the first phases by producing outflows which, however, tend to be limited to the kpc region. After that, the effects turn into producing large-scale bubbles which could, in the long term, prevent the surrounding gas from cooling. Our results characterise the effect of radio jets in different phases of their evolution, bridging the studies done for radio galaxies in clusters.Comment: 5 Pages 2 figures; Proceedings IAU Symposium No. 359, "Galaxy evolution and feedback across different environments", T. Storchi-Bergmann, R. Overzier, W. Forman & R. Riffel, ed

Short form of the changes in outlook questionnaire: translation and validation of the Chinese version

Background: The Changes in Outlook Questionnaire (CiOQ) is a self-report instrument designed to measure both positive and negative changes following the experience of severely stressful events. Previous research has focused on the Western context. The aim of this study is to translate the short form of the measure (CiOQ-S) into simplified Chinese and examine its validity and reliability in a sample of Chinese earthquake survivors. Method: The English language version of the 10-item CiOQ was translated into simplified Chinese and completed along with other measures in a sample of earthquake survivors (n = 120). Statistical analyses were performed to explore the structure of the simplified Chinese version of CiOQ-S (CiOQ-SCS), its reliability and validity. Results: Principal components analysis (PCA) was conducted to test the structure of the CiOQ-SCS. The reliability and convergent validity were also assessed. The CiOQ-SCS demonstrated a similar factor structure to the English version, high internal consistency and convergent validity with measures of posttraumatic stress symptoms, anxiety and depression, coping and social support. Conclusion: The data are comparable to those reported for the original version of the instrument indicating that the CiOQ-SCS is a reliable and valid measure assessing positive and negative changes in the aftermath of adversity. However, the sampling method cannot permit us to know how representative our samples were of the earthquake survivor population

Normative Conflict & Feuds: The Limits of Self-Enforcement

A normative conflict arises when there exist multiple plausible norms of behavior. In such cases, norm enforcement can lead to a sequence of mutual retaliatory sanctions, which we refer to as a feud. We investigate the hypothesis that normative conflict enhances the likelihood of a feud in a public-good experiment. We find that punishment is much more likely to trigger counter-punishment and start a feud when there is a normative conflict, than in a setting in which no conflict exists. While the possibility of a feud sustains cooperation,the cost of feuding fully offsets the efficiency gains from increased cooperation.normative conflict; peer punishment; feuds; counter-punishment; social norms

The Phase Structure of Mass-Deformed SU(2)xSU(2) Quiver Theory

The phase structure of the finite SU(2)xSU(2) theory with N=2 supersymmetry, broken to N=1 by mass terms for the adjoint-valued chiral multiplets, is determined exactly by compactifying the theory on a circle of finite radius. The exact low-energy superpotential is constructed by identifying it as a linear combination of the Hamiltonians of a certain symplectic reduction of the spin generalized elliptic Calogero-Moser integrable system. It is shown that the theory has four confining, two Higgs and two massless Coulomb vacua which agrees with a simple analysis of the tree-level superpotential of the four-dimensional theory. In each vacuum, we calculate all the condensates of the adjoint-valued scalars.Comment: 12 pages, JHEP.cl