Dark decay of holograms in photorefractive polymers

The decay of holograms stored in photorefractive polymer composites based on poly(N-vinyl-carbazole) with and without extrinsic deep traps is investigated. The photorefractive phase shift is identified as one of the key parameters determining the dark decay dynamics. This has important implications for all kinds of photorefractive imaging applications including holographic data storage. A trade off will be required between accepting a certain degree of hologram distortion due to two-beam coupling on the one hand and achieving high hologram stability during idle periods in the dark with the external field applied on the other

Preparation of Insoluble Hole-Injection Layers by Cationic Ring-Opening Polymerisation of Oxetane-Derivatized TriPhenylamineDimer for Organic Electronics Devices

AbstractWe have demostrated that oxetane-derivatized hole conductors as well as electroluminescent polymers can be crosslinked via cationic ring-opening polymerisation (CROP) without deterioration of their electrical and electro–optical properties. This allows the fabrication of electronic multilayer devices via solution process. Here, we demonstrate three kinds of CROP crosslinking methods. They are (1) oxidative crosslinking, (2) photo crosslinking, and (3) trityl crosslinking. The crosslinking process parameters as well as the fluorescence characteristics and the solvent resistance of the resulting films have been investigated. The result shows that the oxidative crosslinking (1) gives the possibility to obtain the doping effect which increases the conductivity of the insoluble layer, although it reduces the fluorescence characteristics. The photo crosslinking (2) is controlled by irradiation; therefore, it gives the possibility to pixelate or pattern the film (lithography). It shows less fluorescence quenching than in (1). The trityl crosslinking (3) is suitable for the devices which are not pixelated and do not need the doping effect. Irradiation is not applicable here. Finally, we applied the insoluble layers in hole-only devices and blue-emitting OLEDs. We found that introduction of the layers improves the efficiency of the OLEDs

Having pity on our victims to save ourselves:Compassion reduces self-critical emotions and self-blame about past harmful behavior among those who highly identify with their past self

Previous research has shown that people often separate the present self from past selves. Applying knowledge gained from intergroup research to the interpersonal domain, we argue that the degree to which people identify with their past self (self-identification) influences their reaction when recalling a past event during which they harmed another person. Because they feel close to their past self, we expected this to be threatening for high self-identifiers, and expected them to be motivated to avoid self-critical emotions and blame. Using four meta-analyses, conducted on a set of seven experimental studies, we investigated four ways in which high self-identifiers can distance themselves from the event: by feeling compassion, by taking a third-person rather than first-person perspective, by emphasizing ways in which their present self is different to their past self, and by disidentifying with the past self altogether. We found the strongest interaction effects for compassion: whereas a compassion manipulation increased self-critical emotions and self-blame about the past event for low self-identifiers, it decreased them for high self-identifiers. We argue that this occurs because the other-focused nature of compassion allows high self-identifiers subtly to shift the focus away from their harmful behavior. Our concept of past self-identification had stronger effects than a measure of self-continuity beliefs. It also correlated only moderately with the latter, suggesting they are distinct concepts. Our findings suggest that, ironically, the most effective way to protect the self against reminders of an undesirable past, may be to have compassion for our victims

Comparative assessment of neurological vs metabolic allostasis as reflected in human skin fibroblasts

Physiological Science

O modelo regulatório do pré-sal e a neutralização da doença holandesa

Orientador : Prof. Dr. Egon Bockmann MoreiraDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Jurídicas, Programa de Pós-Graduação em Direito. Defesa: Curitiba, 26/02/2016Inclui referências : f. 226-246Resumo: A descoberta de imensos campos de petróleo na camada pré-sal descortina uma série de novas oportunidades de produção de riqueza para o Brasil. Do mesmo modo não se pode fechar os olhos para os riscos que a exploração de um recurso natural abundante pode produzir sobre a economia do país produtor, no que se destaca a doença holandesa. Ela é apta a inviabilizar atividades econômicas não relacionadas com a atividade exploratória, sobretudo a indústria, em virtude da apreciação da taxa de câmbio do país de modo contínuo e duradouro, inviabilizando o acesso a mercados externos, bem como sujeitando a produção local à forte concorrência externa. No bojo desta compreensão torna-se pertinente investigar a adequação da adoção de um regime exploratório de petróleo como mecanismo de neutralização da doença holandesa. No caso brasileiro, cumpre avaliar se a incidência do regime de partilha de produção, com a consequente reversão de parcela do excedente do produto aos cofres públicos, associado com a instituição de Fundo Social constituem mecanismos adequados ao enfrentamento da doença holandesa. Palavras-chave: Indústria, Doença holandesa, Neutralização, Petróleo, Regimes jurídicos de exploração, Concessão, Pré-sal, Partilha de produção, Fundo social.Abstract: The discovery of a massive deposit of offshore oil on the pre-salt layer unveils a series of new opportunities which foster wealth for Brazil. At the same time, it cannot blindfold to the risks that the exploitation of a huge natural resource can cause to the economy of the oil-producer country, highlighting the Dutch disease issue. It cripples the economy activities not related to the exploratory activity, especially the industry, as a consequence of the continuous and perennial exchange rate appreciation that makes unavailable the access to foreign markets, as well as submitting the local production to a strong foreign competition. In the midst of this understanding, it becomes pertinent to investigate the adequacy of the adoption of a petroleum regulatory system as a tool to neutralize the Dutch disease. In the Brazilian case, it is relevant to evaluate if the incidence of the production sharing regime with consequent reversal of a portion of the surplus production to the Treasury in association with the creation of Social Fund are the right tools to cope with the Dutch disease. Keywords: Industry, Dutch disease, Neutralization, Petroleum, Petroleum Legislation, License, Pre-salt, Production Sharing Contract, Social Fund

Genetic aetiology of anxiety disorders

Thesis (MSc)--Stellenbosch University, 2016ENGLISH SUMMARY: Anxiety disorders are among the most prevalent psychiatric disorders among both adults and adolescents. Comorbidity with other psychiatric disorders, including other anxiety disorders, is common and it is clear that a high degree of burden of distress and impairment is associated with the condition. Substantial evidence has been presented to suggest a strong genetic component in the aetiology of anxiety disorders. Twin and family studies suggest that panic disorder, general anxiety disorder, phobias and obsessive-compulsive disorder (OCD) aggregate in families. Twin studies in particular shown greater intrapair resemblance between monozygotic twins compared to dizygotic twins, suggesting a strong genetic component. Several genes have been implicated in the genetic aetiology of anxiety disorders, the most prominent of which are BDNF and SCL6A4. Furthermore, the role of the HPA axis in the regulation of the normal response to fear and stress may be influenced by genes contributing to cortisol functions such as FKBP5 and CRHR1. The severity of childhood trauma can contribute to the development of anxiety disorders by modulating gene expression. In this study anxiety sensitivity (AS) is investigated as a possible predictive marker for development of anxiety disorders. Adolescents (13-18 years of age) were recruited from senior secondary schools in the Cape Town area of the Western Cape. Participants were subjected to psychological screening, which included the childhood anxiety sensitivity index (CASI) as well as the childhood trauma questionnaire (CTQ), and saliva samples were collected and genotyping conducted. Gene-environment (G × E) interactions, focussing on the severity of childhood trauma and selected genetic variants, were investigated to determine how levels of AS in a South African adolescent population were modulated. Our cohort consisted of predominantly Xhosa and Coloured individuals and analysis was done on both ethnic groups separately. Significant findings in FKBP5 and CRHR1 in males of both ethnic groups suggests sex linked effect in genes regulating cortisol function. The severity of childhood trauma was found to modulate selected variants which is in line with previous literature. AS may be seen as a precursor to the development of anxiety- and anxiety-related disorders, and a potential clinical marker for early diagnoses of anxiety disorders.AFRIKAANSE OPSOMMING: Angsversteurings is een van die mees algemene psigiatriese versteurings onder beide volwassenes en tieners. Medemorbiditeit met ander psigiatriese versteurings asook medemorbiditeit onder angsversteurings is algemeen. Verder is dit duidelik dat 'n hoë graad van las van nood en gebrek verband hou met die lyding van angsversteurings. ‘n Aansienlike hoeveelheid bewyse is beskikbaar in die literatuur dat daar 'n sterk genetiese komponent as deel van die etiologie van angsversteurings bestaan. Tweeling en familie studies dui daarop dat paniekversteuring, algemene angsversteuring, fobies en obsessiewe kompulsiewe versteuring in families meer algemeen vertoon. Tweeling studies veral wys groter intra-paar ooreenkoms tussen monosigotiese tweelinge in vergelyking met disigotiese tweelinge, wat dui dat die ooreenkoms geneties is eerder as die omgewing waarin die tweelinge hul self bevind. Verskeie gene word geïmpliseer by die genetiese etiologie van angsversteurings waarvan die mees prominente gene BDNF en SCL6A4 is. Verder, die rol van die HPA-as in die regulering van die normale reaksie op vrees en stres, kan beïnvloed word deur gene wat bydra tot kortisol funksie beheer soos FKBP5 en CRHR1. Kinderjare trauma kan ook bydra tot die ontwikkeling van angsversteurings, asook 'n modulerende uitwerking hê op gene. In hierdie studie word angs sensitiwiteit (AS) ondersoek as 'n moontlike voorspellende merker vir die ontwikkeling van angsversteurings. Adolessente (13-18 jaar oud) is gewerf uit senior sekondêre skole in die Kaapstad-omgewing van die Wes-Kaap om aan die studie deel te neem. Deelnemers is blootgestel aan sielkundige vraelyste soos die kinderjare angs sensitiwiteit indeks (CASI) asook die kinderjare trauma vraelys (CTQ), en speeksel monsters is ingesamel en genotipering is gedoen. Geen-omgewing (G × E) interaksies, met die fokus op die erns van kinderjare trauma en gekose genetiese variante is ondersoek, om ten einde vas te stel hoe vlakke van AS in 'n Suid-Afrikaanse adolessente bevolking is gemoduleer word. Ons studie groep bestaan uit oorwegend Xhosa en Bruin deelnemers en ontleding is gedoen op beide etniese groepe afsonderlik. Beduidende bevindinge in FKBP5 en CRHR1 by mans van beide etniese groepe dui op 'n geslagsgekoppelde effek in gene wat kortisol funksie reguleer. Kinderjare trauma is ook gevind om sekere variante te beïnvloed wat in lyn is met die vorige literatuur bevindings. AS kan gesien word as 'n voorloper tot die ontwikkeling van angs- en-angs verwante versteurings, en dus as 'n potensiële kliniese merker gebruik kan word tot die vroeë diagnoseering van angs versteurings

The ‘other’ side of compassion:How the self avoids responsibility for past wrongs

We feel compassion when we see others suffering. Previous research has shown that this can evoke positive feelings for other people or groups, as well as stimulate a desire to help. This is because compassion entails focusing entirely on the suffering of the other: as a result, we can offer selfless help. The goal of this PhD project was to investigate whether compassion can also produce the opposite effect. We specifically investigated past situations where people caused the suffering of others themselves, or belonged to a group that did. Confrontations with such events can be painful, because we are strongly motivated to maintain a positive perception of ourselves and the groups we belong to. We suspected that compassion may offer a subtle way out in these situations: exactly because we focus exclusively on the suffering of the other, we do not have to concern ourselves with our harmful behaviour that caused it in the first place. Our results support this prediction. The degree to which people identify with the group or with the person they were when they committed the harm turned out to be a crucial factor: when people were not strongly identified, compassion led to an increase in self-critical emotions (such as guilt, anger and shame) and feelings of responsibility. But when they were strongly identified, compassion decreased these emotions and feelings. Our research thus shows that the function of emotions strongly depends on people’s underlying motivations