78 research outputs found
Improved Fixed-Budget Results via Drift Analysis
Fixed-budget theory is concerned with computing or bounding the fitness value
achievable by randomized search heuristics within a given budget of fitness
function evaluations. Despite recent progress in fixed-budget theory, there is
a lack of general tools to derive such results. We transfer drift theory, the
key tool to derive expected optimization times, to the fixed-budged
perspective. A first and easy-to-use statement concerned with iterating drift
in so-called greed-admitting scenarios immediately translates into bounds on
the expected function value. Afterwards, we consider a more general tool based
on the well-known variable drift theorem. Applications of this technique to the
LeadingOnes benchmark function yield statements that are more precise than the
previous state of the art.Comment: 25 pages. An extended abstract of this paper will be published in the
proceedings of PPSN 202
Involuntary psychiatric hospitalisation, stigma stress and recovery: a 2-year study
AIMS
Compulsory admission can be experienced as devaluing and stigmatising by people with mental illness. Emotional reactions to involuntary hospitalisation and stigma-related stress may affect recovery, but longitudinal data are lacking. We, therefore, examined the impact of stigma-related emotional reactions and stigma stress on recovery over a 2-year period.
METHOD
Shame and self-contempt as emotional reactions to involuntary hospitalisation, stigma stress, self-stigma and empowerment, as well as recovery were assessed among 186 individuals with serious mental illness and a history of recent involuntary hospitalisation.
RESULTS
More shame, self-contempt and stigma stress at baseline were correlated with increased self-stigma and reduced empowerment after 1 year. More stigma stress at baseline was associated with poor recovery after 2 years. In a longitudinal path analysis more stigma stress at baseline predicted poorer recovery after 2 years, mediated by decreased empowerment after 1 year, controlling for age, gender, symptoms and recovery at baseline.
CONCLUSION
Stigma stress may have a lasting detrimental effect on recovery among people with mental illness and a history of involuntary hospitalisation. Anti-stigma interventions that reduce stigma stress and programs that enhance empowerment could improve recovery. Future research should test the effect of such interventions on recovery
Absorption and Metabolism of cis-9,trans-11-CLA and of Its Oxidation Product 9,11-Furan Fatty Acid by Caco-2 Cells
Furan fatty acids (furan-FA) can be formed by auto-oxidation of conjugated linoleic acids (CLA) and may therefore be ingested when CLA-containing foodstuff is consumed. Due to the presence of a furan ring structure, furan-FA may have toxic properties, however, these substances are toxicologically not well characterized so far. Here we show that 9,11-furan-FA, the oxidation product of the major CLA isomer cis-9,trans-11-CLA (c9,t11-CLA), is not toxic to human intestinal Caco-2 cells up to a level of 100 μM. Oil-Red-O staining indicated that 9,11-furan-FA as well as c9,t11-CLA and linoleic acid are taken up by the cells and stored in the form of triglycerides in lipid droplets. Chemical analysis of total cellular lipids revealed that 9,11-furan-FA is partially elongated probably by the enzymatic activity of cellular fatty acid elongases whereas c9,t11-CLA is partially converted to other isomers such as c9,c11-CLA or t9,t11-CLA. In the case of 9,11-furan-FA, there is no indication for any modification or activation of the furan ring system. From these results, we conclude that 9,11-furan-FA has no properties of toxicological relevance at least for Caco-2 cells which serve as a model for enterocytes of the human small intestine
Langstroth hive construction with cement-vermiculite
Exfoliated vermiculite is a light-weight and cheap product that, because of its thermal resistance, has become a valuable insulating material. With regard to its use in beekeeping, this research tested whether the box for honey bees constructed with cement-vermiculite mortar (CVM) presents physical characteristics similar to those of wood. The experiment was carried out at Seropédica, RJ, Brazil, for eight months. The cement-vermiculite mortar was compared with a control material (pinewood), in the construction of Langstroth boxes and boards, in a completely randomized design, with respect to thermal control, thermal conductivity and its capacity to absorb and lose water. The production cost for a CVM box was estimated. There were no internal temperature differences between CVM and wooden boxes. Thermal conductivity values for CVM and pinewood were similar. CVM absorbed more water and lost water faster than pinewood. Since CVM boxes can be easily constructed, at a low cost and with similar characteristics as traditional boxes, made of wood, the material can be recommended for use in non-migratory beekeeping
Selective and “Veiled” Demarketing from the Perspective of Black Female Consumers
This study sheds light on the perspective of Black female consumers in regards to certain effects of marketing initiatives adopting the literature on demarketing as a framework. The context examined is their experience with the market of hair beauty and care. Media actions are analyzed along narrative interviews in order to understand the phenomenon. The findings reveal a structural dominant pattern which perpetuates the marginalized status of Black women’s natural traits. Emerging market initiatives point to movements concerning the visibility of such female consumers, who despite being eager to consume, have their demand discouraged. This suggests that they perceive a selective and veiled demarketing, as one of the results of marketing actions. The analysis invites for theoretical reflections on demarketing and veiled racism in Brazil
Maternal plasma levels of oxytocin during physiological childbirth - a systematic review with implications for uterine contractions and central actions of oxytocin
Oxytocin is a key hormone in childbirth, and synthetic oxytocin is widely administered to induce or speed labour. Due to lack of synthetized knowledge, we conducted a systematic review of maternal plasma levels of oxytocin during physiological childbirth, and in response to infusions of synthetic oxytocin, if reported in the included studies. An a priori protocol was designed and a systematic search was conducted in PubMed, CINAHL, and PsycINFO in October 2015. Search hits were screened on title and abstract after duplicates were removed (n = 4039), 69 articles were examined in full-text and 20 papers met inclusion criteria. As the articles differed in design and methodology used for analysis of oxytocin levels, a narrative synthesis was created and the material was categorised according to effects. Basal levels of oxytocin increased 3-4-fold during pregnancy. Pulses of oxytocin occurred with increasing frequency, duration, and amplitude, from late pregnancy through labour, reaching a maximum of 3 pulses/10 min towards the end of labour. There was a maximal 3- to 4-fold rise in oxytocin at birth. Oxytocin pulses also occurred in the third stage of labour associated with placental expulsion. Oxytocin peaks during labour did not correlate in time with individual uterine contractions, suggesting additional mechanisms in the control of contractions. Oxytocin levels were also raised in the cerebrospinal fluid during labour, indicating that oxytocin is released into the brain, as well as into the circulation. Oxytocin released into the brain induces beneficial adaptive effects during birth and postpartum. Oxytocin levels following infusion of synthetic oxytocin up to 10 mU/min were similar to oxytocin levels in physiological labour. Oxytocin levels doubled in response to doubling of the rate of infusion of synthetic oxytocin. Plasma oxytocin levels increase gradually during pregnancy, and during the first and second stages of labour, with increasing size and frequency of pulses of oxytocin. A large pulse of oxytocin occurs with birth. Oxytocin in the circulation stimulates uterine contractions and oxytocin released within the brain influences maternal physiology and behaviour during birth. Oxytocin given as an infusion does not cross into the mother's brain because of the blood brain barrier and does not influence brain function in the same way as oxytocin during normal labour does
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