The Role of Adventitious Reinforcement in Operant Discrimination

Rats were trained in 2 SD-SΔ discrimination experiments in which the effects of an SD-postponement contingency during SΔ and temporal regularity of SΔ duration were assessed. Experiment I showed that discrimination is markedly facilitated by the presence of an SD-postponement contingency of either fixed or variable duration. Experiment II showed that variable-duration SΔ periods in a noncontingent schedule can also greatly enhance formation of an operant discrimination. These effects were attributed to differences in the probability of adventitious reinforcement of SΔ behavior by SD events

Oxylipins in triglyceride-rich lipoproteins of dyslipidemic subjects promote endothelial inflammation following a high fat meal.

Elevated triglyceride-rich lipoproteins (TGRL) in circulation is a risk factor for atherosclerosis. TGRL from subjects consuming a high saturated fat test meal elicited a variable inflammatory response in TNFα-stimulated endothelial cells (EC) that correlated strongly with the polyunsaturated fatty acid (PUFA) content. This study investigates how the relative abundance of oxygenated metabolites of PUFA, oxylipins, is altered in TGRL postprandially, and how these changes promote endothelial inflammation. Human aortic EC were stimulated with TNFα and treated with TGRL, isolated from subjects' plasma at fasting and 3.5 hrs postprandial to a test meal high in saturated fat. Endothelial VCAM-1 surface expression stimulated by TNFα provided a readout for atherogenic inflammation. Concentrations of esterified and non-esterified fatty acids and oxylipins in TGRL were quantified by mass spectrometry. Dyslipidemic subjects produced TGRL that increased endothelial VCAM-1 expression by ≥35%, and exhibited impaired fasting lipogenesis activity and a shift in soluble epoxide hydrolase and lipoxygenase activity. Pro-atherogenic TGRL were enriched in eicosapentaenoic acid metabolites and depleted in esterified C18-PUFA-derived diols. Abundance of these metabolites was strongly predictive of VCAM-1 expression. We conclude the altered metabolism in dyslipidemic subjects produces TGRL with a unique oxylipin signature that promotes a pro-atherogenic endothelial phenotype

Lost in space: introducing the spatial dispositif in space-sensitive discourse research

The appearance of New Materialism has brought about a rupture in the social sciences and opened new positions to analyze social entities like space. In our contribution, we claim that it also offers a starting point for theoretical considerations in reference to the relationship between discourse, space and materiality – especially regarding the perspective of materialization beyond a culture-nature-dichotomy. In our research on the German-Polish border area, we combined »classical« studies of newspapers with the study of discursive practices among local residents. Here, the questions that arose for us were: To what extent is material space important for our discourse analysis? And how can it be included as an element in our conceptualization of discourse on space? Building on Foucault’s idea of the dispositif and Barad’s understanding of materiality, we introduce the spatial dispositif as a way to conceptualize discourse-material interrelations in the analysis of space

Concerning the Verity of the MMRD Relation for Novae

It has long been claimed that novae reaching the highest luminosity at the peak of their eruptions appear to fade the fastest from maximum light. The relationship between peak brightness and fade rate is known as the Maximum-Magnitude, Rate-of-Decline (MMRD) relation. Lightcurve parameters for the most recent sample of M31 recurrent novae are presented and used to buttress the case that the observed MMRD relation can be explained as a consequence of observational selection effects coupled with expectations from standard nova models.Comment: 5 pages; 1 figure; 1 table (figure data); abbreviated version accepted for publication in Research Notes of the AA

Do the Outburst Properties of M31N 2008-12a Depend on the Time Since the Previous Eruption?

Photometric observations spanning the UV to the near IR during the nine most recent eruptions (2014-2022) of the extragalactic nova M31N 2008-12a are presented and analyzed in order to explore whether the lightcurve properties for a given eruption, specifically the peak magnitudes and fade rates, are correlated with the time interval since the previous eruption. No significant correlation between the pre-eruption interval and the rate of decline was found, however it appears that the brightness at the peak of an outburst may be positively correlated with the time interval since the previous eruption.Comment: 5 pages, 1 figure, 1 table (data behind the figure); accepted for publication in Research Notes of the AA

Implementation and evaluation of improved Gaussian sampling for lattice trapdoors

We report on our implementation of a new Gaussian sampling algorithm for lattice trapdoors. Lattice trapdoors are used in a wide array of lattice-based cryptographic schemes including digital signatures, attributed-based encryption, program obfuscation and others. Our implementation provides Gaussian sampling for trapdoor lattices with prime moduli, and supports both single- and multi-threaded execution. We experimentally evaluate our implementation through its use in the GPV hash-and-sign digital signature scheme as a benchmark. We compare our design and implementation with prior work reported in the literature. The evaluation shows that our implementation 1) has smaller space requirements and faster runtime, 2) does not require multi-precision floating-point arithmetic, and 3) can be used for a broader range of cryptographic primitives than previous implementations