Real root finding for equivariant semi-algebraic systems

Let $R$ be a real closed field. We consider basic semi-algebraic sets defined by $n$-variate equations/inequalities of $s$ symmetric polynomials and an equivariant family of polynomials, all of them of degree bounded by $2d < n$. Such a semi-algebraic set is invariant by the action of the symmetric group. We show that such a set is either empty or it contains a point with at most $2d-1$ distinct coordinates. Combining this geometric result with efficient algorithms for real root finding (based on the critical point method), one can decide the emptiness of basic semi-algebraic sets defined by $s$ polynomials of degree $d$ in time $(sn)^{O(d)}$. This improves the state-of-the-art which is exponential in $n$. When the variables $x_1, \ldots, x_n$ are quantified and the coefficients of the input system depend on parameters $y_1, \ldots, y_t$, one also demonstrates that the corresponding one-block quantifier elimination problem can be solved in time $(sn)^{O(dt)}$

Årbok 1964

To date, only one study by Strick and Volbeda (2018), titled ‘When the valence of unconditioned stimuli evolves over time: Evaluative conditioning with good-ending and bad-ending stories’, investigated stories in the context of evaluative conditioning to change brand attitudes. To find additional support for stories as unconditioned stimuli, we performed a partial replication of this study. As an extension, we also investigated the role of the need for affect as a mediator in this conditioning process. Our study had a within-subject design, in which MTurk workers (N = 66) participated in both our good- and bad-ending story conditions. In line with the original study and our hypothesis, our results suggest that the valence of the story ending determines the direction of the conditioning effect. Brands presented after good-ending stories have a stronger brand liking than brands presented after bad-ending stories. In practice, this would imply that advertisements should always end positively to induce a positive brand evaluation. Furthermore, as we hypothesized, our results indicate that the need for affect mediates this conditioning effect as people with a high need for affect rate brands more emotionally and strongly according to the story-ending valence than people with a low need for affect. Future research may distinguish other characteristics that mediate this effect to identify separate groups for targeted advertisements. To conclude, the ending of dramatic stories is determinative in brand evaluation when the brand is presented directly after, and the effect of these story endings is mediated by the need for affect

Extinction of cue-evoked food seeking recruits a GABAergic interneuron ensemble in the dorsal medial prefrontal cortex of mice

Animals must quickly adapt food-seeking strategies to locate nutrient sources in dynamically changing environments. Learned associations between food and environmental cues that predict its availability promote food-seeking behaviors. However, when such cues cease to predict food availability, animals undergo 'extinction' learning, resulting in the inhibition of food-seeking responses. Repeatedly activated sets of neurons, or 'neuronal ensembles', in the dorsal medial prefrontal cortex (dmPFC) are recruited following appetitive conditioning and undergo physiological adaptations thought to encode cue-reward associations. However, little is known about how the recruitment and intrinsic excitability of such dmPFC ensembles are modulated by extinction learning. Here, we used in vivo 2-Photon imaging in male Fos-GFP mice that express green fluorescent protein (GFP) in recently behaviorally-activated neurons to determine the recruitment of activated pyramidal and GABAergic interneuron mPFC ensembles during extinction. During extinction, we revealed a persistent activation of a subset of interneurons which emerged from a wider population of interneurons activated during the initial extinction session. This activation pattern was not observed in pyramidal cells, and extinction learning did not modulate the excitability properties of activated neurons. Moreover, extinction learning reduced the likelihood of reactivation of pyramidal cells activated during the initial extinction session. Our findings illuminate novel neuronal activation patterns in the dmPFC underlying extinction of food-seeking, and in particular, highlight an important role for interneuron ensembles in this inhibitory form of learning

Ages for illustrative field stars using gyrochronology: viability, limitations and errors

We here develop an improved way of using a rotating star as a clock, set it using the Sun, and demonstrate that it keeps time well. This technique, called gyrochronology, permits the derivation of ages for solar- and late-type main sequence stars using only their rotation periods and colors. The technique is clarified and developed here, and used to derive ages for illustrative groups of nearby, late-type field stars with measured rotation periods. We first demonstrate the reality of the interface sequence, the unifying feature of the rotational observations of cluster and field stars that makes the technique possible, and extends it beyond the proposal of Skumanich by specifying the mass dependence of rotation for these stars. We delineate which stars it cannot currently be used on. We then calibrate the age dependence using the Sun. The errors are propagated to understand their dependence on color and period. Representative age errors associated with the technique are estimated at ~15% (plus possible systematic errors) for late-F, G, K, & early-M stars. Ages derived via gyrochronology for the Mt. Wilson stars are shown to be in good agreement with chromospheric ages for all but the bluest stars, and probably superior. Gyro ages are then calculated for each of the active main sequence field stars studied by Strassmeier and collaborators where other ages are not available. These are shown to be mostly younger than 1Gyr, with a median age of 365Myr. The sample of single, late-type main sequence field stars assembled by Pizzolato and collaborators is then assessed, and shown to have gyro ages ranging from under 100Myr to several Gyr, and a median age of 1.2Gyr. Finally, we demonstrate that the individual components of the three wide binaries XiBooAB, 61CygAB, & AlphaCenAB yield substantially the same gyro ages.Comment: 58 pages, 18 color figures, accepted for publication in The Astrophysical Journal; Age uncertainties slightly modified upon correcting an algebraic error in Section

Do Others Judge My Humor Style as I Do? Self-Other Agreement and Construct Validity of the Humor Styles Questionnaire

Abstract. Humor research has intensified in psychology over the last two decades, with the Humor Styles Questionnaire (HSQ) being the most prevalent measure. Still, the construct validity of its four scales (affiliative, self-enhancing, aggressive, and self-defeating) has not received unequivocal support. The present study uses a multitrait-multimethod approach to test the self-other agreement of the four HSQ scales with 202 targets and two knowledgeable informants per target. Employing a multilevel multiple-indicator correlated trait-correlated (method-1) (ML-CT-C[M-1]) model informed on the construct validity of the HSQ. Discriminant validities were sufficient for all scales. Convergent validity was supported for three of the four HSQ scales, except for the self-defeating scale. Similarly, the overlaps of the self- and other-reported HSQ scales with maladaptive personality as external criteria converged for all HSQ scales except for the self-defeating scale. Taken together, the present findings suggest that the self-defeating scale does not measure the maladaptive humor style it is supposed to measure. </jats:p

Putting a spotlight on daily humor behaviors: Dimensionality and relationships with personality, subjective well-being, and humor styles

Although psychological humor research has expanded in the last decades, the humor behaviors that people show in their everyday lives are still poorly understood. To fill this gap, this diary study explores the dimensionality of 45 daily humor behaviors and their relationships with the Big Five personality traits and subjective well-being. Furthermore, the humor behaviors were utilized to investigate the criterion validity of the Humor Styles Questionnaire. A hierarchical factor analysis of the humor behaviors (N = 123) revealed seven dimensions: Cheerful, witty, deriding, amused, sarcastic, self-directed, and canned. These humor behavior dimensions correlated with emotional stability, extraversion, lower agreeableness, and culture/openness. Also cheerful, amused, and self-directed humor behaviors correlated positively with subjective well-being, even when personality and the humor styles were controlled for. The criterion correlations of the humor styles to their constituting humor behaviors were medium to large for affiliative and self-enhancing, and small to medium for aggressive and self-defeating. Overall, investigating humor behaviors seems a promising venue for future research and applications of individual differences in humor

Gender differences in diet-induced steatotic disease in Cyp2b-null mice

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease; however, progression to nonalcoholic steatohepatitis (NASH) is associated with most adverse outcomes. CYP2B metabolizes multiple xeno- and endobiotics, and male Cyp2b-null mice are diet-induced obese (DIO) with increased NAFLD. However, the DIO study was not performed long enough to assess progression to NASH. Therefore, to assess the role of Cyp2b in fatty liver disease progression from NAFLD to NASH, we treated wildtype (WT) and Cyp2b-null mice with a normal diet (ND) or choline-deficient, L-amino acid-defined high fat diet (CDAHFD) for 8 weeks and determined metabolic and molecular changes. CDAHFD-fed WT female mice gained more weight and had greater liver and white adipose tissue mass than their Cyp2b-null counterparts; males experienced diet-induced weight loss regardless of genotype. Serum biomarkers of liver injury increased in both CDAHFD-fed female and male mice; however CDAHFD-fed Cyp2b-null females exhibited significantly lower serum ALT, AST, and ASP concentrations compared to WT mice, indicating Cyp2b-null females were protected from liver injury. In both genders, hierarchical clustering of RNA-seq data demonstrates several gene ontologies responded differently in CDAHFD-fed Cyp2b-null mice compared to WT mice (lipid metabolism \u3e fibrosis \u3e inflammation). Oil Red O staining and direct triglycerides measurements confirmed that CDAHFD-fed Cyp2b-null females were protected from NAFLD. CDAHFD-fed Cyp2b-null mice showed equivocal changes in fibrosis with transcriptomic and serum markers suggesting less inflammation due to glucocorticoid-mediated repression of immune responses. In contrast to females, CDAHFD-fed Cyp2b-null males had higher triglyceride levels. Results indicate that female Cyp2b-null mice are protected from NAFLD while male Cyp2b-null mice are more susceptible to NAFLD, with few significant changes in NASH development. This study confirms that increased NAFLD development does not necessarily lead to progressive NASH. Furthermore, it indicates a role for Cyp2b in fatty liver disease that differs based on gender

Spectroscopy at B-factories Using Hard Photon Emission

The process of hard photon emission by initial electrons (positrons) at B-factories is discussed. It is shown that studies of the bottomonium spectroscopy will be feasible for the planned integrated luminosity of the B-factory experiments.Comment: 9 pages, Latex, 1 fugure, Submitted to Int.Jour.Mod.Phys.