The Affective Impact of Financial Skewness on Neural Activity and Choice

Few finance theories consider the influence of “skewness” (or large and asymmetric but unlikely outcomes) on financial choice. We investigated the impact of skewed gambles on subjects' neural activity, self-reported affective responses, and subsequent preferences using functional magnetic resonance imaging (FMRI). Neurally, skewed gambles elicited more anterior insula activation than symmetric gambles equated for expected value and variance, and positively skewed gambles also specifically elicited more nucleus accumbens (NAcc) activation than negatively skewed gambles. Affectively, positively skewed gambles elicited more positive arousal and negatively skewed gambles elicited more negative arousal than symmetric gambles equated for expected value and variance. Subjects also preferred positively skewed gambles more, but negatively skewed gambles less than symmetric gambles of equal expected value. Individual differences in both NAcc activity and positive arousal predicted preferences for positively skewed gambles. These findings support an anticipatory affect account in which statistical properties of gambles—including skewness—can influence neural activity, affective responses, and ultimately, choice

Self‐reported sleep quality is more closely associated with mental and physical health than chronotype and sleep duration in young adults: A multi‐instrument analysis

Sleep and circadian rhythms are considered to be important determinants of mental and physical health. Epidemiological studies have established the contribution of self‐reported sleep duration, sleep quality and chronotype to health outcomes. Mental health and sleep problems are more common in women and men are more likely to be evening types. Few studies have compared the relative strength of these contributions and few studies have assessed these contributions separately in men and women. Furthermore, sleep and circadian characteristics are typically assessed with a limited number of instruments and a narrow range of variables is considered, leaving the understanding of the relative contribution of different predictors somewhat fractionary. We compared sleep quality, sleep duration and chronotype as predictors for self‐reported mental and physical health and psychological characteristics in 410 men and 261 women aged 18 to 30. To ascertain that results were not dependent on the use of specific instruments we used a multitude of validated instruments including the Morningness‐Eveningness‐Questionnaire, Munich‐ChronoType‐Questionnaire, Pittsburgh‐Sleep‐Quality‐Index, British‐Sleep‐Survey, Karolinska‐Sleep‐Diary, Insomnia‐Severity‐Index, SF‐36‐Health Survey, General‐Health‐Questionnaire, Dutch‐Eating‐Behaviour‐Questionnaire, Big‐Five‐Inventory, Behaviour‐Inhibition‐System‐Behaviour‐Activation‐System, and the Positive‐Affect‐Negative‐Affect‐Schedule. Relative contributions of predictors were quantified as local effect sizes derived from multiple regression models. Across all questionnaires, sleep quality was the strongest independent predictor of health and in particular mental health and more so in women than in men. The effect of sleep duration and social jetlag was inconspicuous. A greater insight into the independent contributions of sleep quality and chronotype may aid the understanding of sleep‐health interactions in women and men

The EVIL-MC Model for Ellipsoidal Variations of Planet-Hosting Stars and Applications to the HAT-P-7 System

We present a new model for Ellipsoidal Variations Induced by a Low-Mass Companion, the EVIL-MC model. We employ several approximations appropriate for planetary systems to substantially increase the computational efficiency of our model relative to more general ellipsoidal variation models and improve upon the accuracy of simpler models. This new approach gives us a unique ability to rapidly and accurately determine planetary system parameters. We use the EVIL-MC model to analyze Kepler Quarter 0-2 (Q0-2) observations of the HAT-P-7 system, an F-type star orbited by a nearly Jupiter-mass companion. Our analysis corroborates previous estimates of the planet-star mass ratio q = (1.10 +/- 0.06) x 10^(-3), and we have revised the planet's dayside brightness temperature to 2680 +10/-20 K. We also find a large difference between the day- and nightside planetary flux, with little nightside emission. Preliminary dynamical+radiative modeling of the atmosphere indicates this result is qualitatively consistent with high altitude absorption of stellar heating. Similar analyses of Kepler and CoRoT photometry of other planets using EVIL-MC will play a key role in providing constraints on the properties of many extrasolar systems, especially given the limited resources for follow-up and characterization of these systems. However, as we highlight, there are important degeneracies between the contributions from ellipsoidal variations and planetary emission and reflection. Consequently, for many of the hottest and brightest Kepler and CoRoT planets, accurate estimates of the planetary emission and reflection, diagnostic of atmospheric heat budgets, will require accurate modeling of the photometric contribution from the stellar ellipsoidal variation.Comment: Accepted to ApJ; minor revisions to original submission; An IDL version of the EVIL-MC model is publicly available at http://www.lpl.arizona.edu/~bjackson/idl_code/index.htm

More Evidence for Variable Helium Absorption from HD 189733b

We present a new Keck/NIRSPEC observation of metastable helium absorption from the upper atmosphere of HD 189733b, a hot Jupiter orbiting a nearby moderately active star. We measure an average helium transit depth of $0.420 \pm 0.013$% integrated over the [-20, 20] km/s velocity range. Comparing this measurement to eight previously published transit observations with different instruments, we find that our depth is 32% (9$\sigma$) lower than the average of the three CARMENES transits, but only 16% (4.4$\sigma$) lower than the average of the five GIANO transits. We perform 1D hydrodynamical simulations of the outflow, and find that XUV variability on the order of 33%--common for this star--can change the helium absorption depth by 60%. We conclude that changes in stellar XUV flux can explain the observational variability in helium absorption. 3D models are necessary to explore other sources of variability, such as shear instability and changing stellar wind conditions.Comment: Published by A

HST PanCET program: A Cloudy Atmosphere for the promising JWST target WASP-101b

We present results from the first observations of the Hubble Space Telescope (HST) Panchromatic Comparative Exoplanet Treasury (PanCET) program for WASP-101b, a highly inflated hot Jupiter and one of the community targets proposed for the James Webb Space Telescope (JWST) Early Release Science (ERS) program. From a single HST Wide Field Camera 3 (WFC3) observation, we find that the near-infrared transmission spectrum of WASP-101b contains no significant H$_2$O absorption features and we rule out a clear atmosphere at 13{\sigma}. Therefore, WASP-101b is not an optimum target for a JWST ERS program aimed at observing strong molecular transmission features. We compare WASP-101b to the well studied and nearly identical hot Jupiter WASP-31b. These twin planets show similar temperature-pressure profiles and atmospheric features in the near-infrared. We suggest exoplanets in the same parameter space as WASP-101b and WASP-31b will also exhibit cloudy transmission spectral features. For future HST exoplanet studies, our analysis also suggests that a lower count limit needs to be exceeded per pixel on the detector in order to avoid unwanted instrumental systematics.Comment: 7 pages, 4 figures, 1 table, Accepted to ApJ

Future changes in tropical cyclone activity in the North Indian Ocean projected by high-resolution MRI-AGCMs

Open Access at publisher's web site: http://www.springerlink.com/content/b682734237171631

Conditioning bounds for traveltime tomography in layered media

This paper revisits the problem of recovering a smooth, isotropic, layered wave speed profile from surface traveltime information. While it is classic knowledge that the diving (refracted) rays classically determine the wave speed in a weakly well-posed fashion via the Abel transform, we show in this paper that traveltimes of reflected rays do not contain enough information to recover the medium in a well-posed manner, regardless of the discretization. The counterpart of the Abel transform in the case of reflected rays is a Fredholm kernel of the first kind which is shown to have singular values that decay at least root-exponentially. Kinematically equivalent media are characterized in terms of a sequence of matching moments. This severe conditioning issue comes on top of the well-known rearrangement ambiguity due to low velocity zones. Numerical experiments in an ideal scenario show that a waveform-based model inversion code fits data accurately while converging to the wrong wave speed profile

A Preliminary List of Some Families of Iowa Insects

For some ten years the Iowa Insect Survey has been collecting specimens and data from all parts of this state in a study of the geographic and seasonal distribution of the insects of Iowa. Comparatively little has been done heretofore with most of the families of the Hymenoptera and the Diptera of Iowa. With the hope of stimulating a more general interest in these groups, preliminary lists of the species now known to occur within the state are being submitted. Students in systematic Entomology in the college have taken a family and given it special attention in their collecting for one or more years. These students have collaborated with the senior author in the preparation of this paper. The name of the student thus taking the responsibility of getting a list for a family in shape is printed at the head of the list. Determinations throughout the list have been made or checked by specialists as indicated for each group. Assistance given by the Iowa Academy of Science and the State University of Iowa has helped materially in keeping the Survey going

Decadal Climate Information Needs of Stakeholders for Decision Support in Water and Agriculture Production Sectors: A Case Study in the Missouri River Basin

Many decadal climate prediction efforts have been initiated under phase 5 of the World Climate Research Programme Coupled Model Intercomparison Project. There is considerable ongoing discussion about model deficiencies, initialization techniques, and data requirements, but not much attention is being given to decadal climate information (DCI) needs of stakeholders for decision support. Here, the authors report the results of exploratory activities undertaken to assess DCI needs in water resources and agriculture sectors, using the Missouri River basin as a case study. This assessment was achieved through discussions with 120 stakeholders. Stakeholders’ awareness of decadal dry and wet spells and their societal impacts in the basin are described, and stakeholders’ DCI needs and potential barriers to their use of DCI are enumerated. The authors find that impacts, including economic impacts, of decadal climate variability (DCV) on water and agricultural production in the basin are distinctly identifiable and characterizable. Stakeholders have clear notions about their needs for DCI and have offered specific suggestions as to how these might be met. However, while stakeholders are eager to have climate information, including decadal climate outlooks (DCOs), there are many barriers to the use of such information. The first and foremost barrier is that the credibility ofDCOs is yet to be established. Second, the nature of institutional rules and regulations, laws, and legal precedents that pose obstacles to the use of DCOs must be better understood and means to modify these, where possible, must be sought. For the benefit of climate scientists, these and other stakeholder needs are also articulated in this paper