"Utilizing" Signal Detection Theory Lynn, Spencer K.; Barrett, Lisa Feldman
Psychological science,
09/2014, Letnik:
25, Številka:
9
Journal Article
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What do inferring what a person is thinking or feeling, judging a defendant's guilt, and navigating a dimly lit room have in common? They involve perceptual uncertainty (e.g., a scowling face might ...indicate anger or concentration, for which different responses are appropriate) and behavioral risk (e.g., a cost to making the wrong response). Signal detection theory describes these types of decisions. In this tutorial, we show how incorporating the economic concept of utility allows signal detection theory to serve as a model of optimal decision making, going beyond its common use as an analytic method. This utility approach to signal detection theory clarifies otherwise enigmatic influences of perceptual uncertainty on measures of decision-making performance (accuracy and optimality) and on behavior (an inverse relationship between bias magnitude and sensitivity optimizes utility). A "utilized" signal detection theory offers the possibility of expanding the phenomena that can be understood within a decision-making framework.
In the context of phase 5 of the Coupled Model Intercomparison Project, most climate simulations use prescribed atmospheric CO₂ concentration and therefore do not interactively include the effect of ...carbon cycle feedbacks. However, the representative concentration pathway 8.5 (RCP8.5) scenario has additionally been run by earth system models with prescribed CO₂ emissions. This paper analyzes the climate projections of 11 earth system models (ESMs) that performed both emission-driven and concentration-driven RCP8.5 simulations. When forced by RCP8.5 CO₂ emissions, models simulate a large spread in atmospheric CO₂; the simulated 2100 concentrations range between 795 and 1145 ppm. Seven out of the 11 ESMs simulate a larger CO₂ (on average by 44 ppm, 985 ± 97 ppm by 2100) and hence higher radiative forcing (by 0.25 W m−2) when driven by CO₂ emissions than for the concentration-driven scenarios (941 ppm). However, most of these models already overestimate the present-day CO₂, with the present-day biases reasonably well correlated with future atmospheric concentrations’ departure from the prescribed concentration. The uncertainty in CO₂ projections is mainly attributable to uncertainties in the response of the land carbon cycle. As a result of simulated higher CO₂ concentrations than in the concentration-driven simulations, temperature projections are generally higher when ESMs are driven with CO₂ emissions. Global surface temperature change by 2100 (relative to present day) increased by 3.9° ± 0.9°C for the emission-driven simulations compared to 3.7° ± 0.7°C in the concentration-driven simulations. Although the lower ends are comparable in both sets of simulations, the highest climate projections are significantly warmer in the emission-driven simulations because of stronger carbon cycle feedbacks.
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BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Field theoretic simulations are used to predict the equilibrium phase diagram of symmetric blends of AB diblock copolymer with A- and B-type homopolymers. Experiments generally observe a channel of ...bicontinuous microemulsion (BμE) separating the ordered lamellar (LAM) phase from coexisting homopolymer-rich (A+B) phases. However, our simulations find that the channel is unstable with respect to macrophase separation, in particular, A+B+BμE coexistence at high T and A+B+LAM coexistence at low T. The preference for three-phase coexistence is attributed to a weak attractive interaction between diblock monolayers.
Catholic philosophical anthropologists have defended views of the human person on which we are irreducible to anything non-personal. For example, it is not the case that we are nothing but matter, ...souls, or parts of society. But many Catholic anthropologies have overlooked ways in which we are irreducible and so have not given an adequate account of the uniqueness of each human person. This book presents a philosophical portrait of human persons that depicts each way in which we are irreducible, with the goal of guiding the reader to perceive, wonder at, and love all the unique features of human persons. It builds this portrait by showing how claims from many strands of the Catholic tradition can be synthesized. These strands include Thomism, Scotism, phenomenology, personalism, nouvelle théologie, analytic philosophy, and Greek and Russian thought. The book focuses on how these traditions’ claims are grounded in experience and on how they help us to perceive irreducible features of persons. While many metaphysical claims about persons are defended, the picture of persons that ultimately emerges is one on which persons are best grasped not through abstract concepts but through aesthetic perception and love, as unique kinds of beauty. This book also explores irreducible features of our subjectivity, senses, intellect, freedom, and affections, and of our souls, bodies, and activities. It includes discussions of divine simplicity and causality, and of the nature of angels, matter, organisms, and artifacts, all of which must be understood to fully grasp our irreducibility. In showing how to synthesize various traditions’ claims, the book also offers new solutions to a number of debates in Catholic philosophy. These include debates over natural law, the natural desire to see God, the separated soul, integralism and personalism, idealist and realist phenomenology, and scholastic accounts of the act of existence.
Principal components analysis (PCA) is a multivariate statistical technique capable of discerning patterns in large environmental datasets. Although widely used, there is disparity in the literature ...with respect to data pre-treatment prior to PCA. This research examines the influence of commonly reported data pre-treatment methods on PCA outputs, and hence data interpretation, using a typical environmental dataset comprising sediment geochemical data from an estuary in SE England. This study demonstrated that applying the routinely used log (x + 1) transformation skewed the data and masked important trends. Removing outlying samples and correcting for the influence of grain size had the most significant effect on PCA outputs and data interpretation. Reducing the influence of grain size using granulometric normalisation meant that other factors affecting metal variability, including mineralogy, anthropogenic sources and distance along the salinity transect could be identified and interpreted more clearly.
Data pre-treatment can have a significant influence on the outcome of PCA.
The residual stress profiles in Cu and Al coatings cold sprayed using kinetic metallization have been studied using neutron diffraction. To interpret results and to describe them quantitatively, the ...measured profiles were fit to Tsui and Clyne’s progressive coating deposition model, which demonstrated that the residual stresses are largely due to kinetic and not thermal effects. The residual stress state of the coatings was found to depend mainly on the deformation behaviour and properties of the coating material, and the kinetic parameters of the cold spray process. Young’s modulus and impact strain were measured and used along with published material data for Cu and Al to approximate the residual stresses, using a model developed for shot peening. The properties of the Cu coatings such as Young’s modulus and porosity were found to be closer to their bulk values than in the case of the Al coatings, and this was related to the amount of particle deformation on impact.
The Palliative Prognostic (PaP) score; Palliative Prognostic Index (PPI); Feliu Prognostic Nomogram (FPN) and Palliative Performance Scale (PPS) have all been proposed as prognostic tools for ...palliative cancer care. However, clinical judgement remains the principal way by which palliative care professionals determine prognoses and it is important that the performance of prognostic tools is compared against clinical predictions of survival (CPS).
This was a multi-centre, cohort validation study of prognostic tools. Study participants were adults with advanced cancer receiving palliative care, with or without capacity to consent. Key prognostic data were collected at baseline, shortly after referral to palliative care services. CPS were obtained independently from a doctor and a nurse.
Prognostic data were collected on 1833 participants. All prognostic tools showed acceptable discrimination and calibration, but none showed superiority to CPS. Both PaP and CPS were equally able to accurately categorise patients according to their risk of dying within 30 days. There was no difference in performance between CPS and FPN at stratifying patients according to their risk of dying at 15, 30 or 60 days. PPI was significantly (p<0.001) worse than CPS at predicting which patients would survive for 3 or 6 weeks. PPS and CPS were both able to discriminate palliative care patients into multiple iso-prognostic groups.
Although four commonly used prognostic algorithms for palliative care generally showed good discrimination and calibration, none of them demonstrated superiority to CPS. Prognostic tools which are less accurate than CPS are of no clinical use. However, prognostic tools which perform similarly to CPS may have other advantages to recommend them for use in clinical practice (e.g. being more objective, more reproducible, acting as a second opinion or as an educational tool). Future studies should therefore assess the impact of prognostic tools on clinical practice and decision-making.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Stress exposure during early‐life development can programme individual brain and physiology. The hypothalamic‐pituitary‐adrenal (HPA) axis is one of the primary targets of this programming, which is ...generally associated with a hyperactive HPA axis, indicative of a reduced negative‐feedback. This reduced feedback efficiency usually results from a reduced level of the glucocorticoid receptor (GR) and/or the mineralocorticoid receptor (MR) within the HPA axis. However, a few studies have shown that early‐life stress exposure results in an attenuated physiological stress response, suggesting an enhance feedback efficiency. In the present study, we aimed to determine whether early‐life stress had long‐term consequences on GR and MR levels in quail and whether the effects on the physiological response to acute stress observed in prenatally stressed individuals were underpinned by changes in GR and/or MR levels in one or more HPA axis components. We determined GR and MR mRNA expression in the hippocampus, hypothalamus and pituitary gland in quail exposed to elevated corticosterone during prenatal development, postnatal development, or both, and in control individuals exposed to none of the stressors. We showed that prenatal stress increased the GR:MR ratio in the hippocampus, GR and MR expression in the hypothalamus and GR expression in the pituitary gland. Postnatal stress resulted in a reduced MR expression in the hippocampus. Both early‐life treatments permanently affected the expression of both receptor types in HPA axis regions. The effects of prenatal stress are in accordance with a more efficient negative‐feedback within the HPA axis and thus can explain the attenuated stress response observed in these birds. Therefore, these changes in receptor density or number as a consequence of early‐life stress exposure might be the mechanism that allows an adaptive response to later‐life stressful conditions.
In this study we implement eight lightning parameterizations in the Community Atmospheric Model (CAM5), evaluate the performance of the parameterizations in the present climate, and test the ...sensitivity of future lightning activity to the choice of parameterization. In the present day, the annual mean lightning flash densities in simulations constrained by reanalysis data show the highest spatial correlation to satellite observations for parameterizations based either on cloud top height (0.83) or cold cloud depth (0.80). Under future scenarios using representative concentration pathways, changes in global mean lightning flash density are highly sensitive to the parameterization chosen, with cloud top height schemes, a cold cloud depth scheme, and a scheme based on convective mass flux projecting large increases (36% to 45%), a mild increase (12.6%), and a decrease (−6.7%) in lightning flash density, respectively, under the RCP8.5 scenario, which causes a 3.4 K warming between 1996–2005 and 2079–2088.
Key Points
Out of eight parameterizations, future lightning flash density (LFD) is projected to change by a median of 3.7% per K warming under RCP8.5
Cold cloud depth and cloud top height schemes perform comparably well in present day, but future projections differ (3.7 versus 12.7% per K)
No scheme tested simulates the 1996‐2008 time series of area mean LFD with a correlation coefficient greater than 0.45 with the OBS
Observations and theory of convectively-coupled equatorial waves suggest that they can be categorized into two distinct groups. Moisture modes are waves whose thermodynamics are governed by moisture ...fluctuations. The thermodynamics of the gravity wave group, on the other hand, are rooted in buoyancy (temperature) fluctuations. On the basis of scale analysis it is found that a simple nondimensional parameter –akin to the Rossby number– can explain the processes that lead to the existence of these two groups. This parameter, defined as Nmode, indicates that moisture modes arise when anomalous convection lasts sufficiently long so that dry gravity waves eliminate the temperature anomalies in the convective region, satisfying weak temperature gradient (WTG) balance. This process causes moisture anomalies to dominate the distribution of moist enthalpy (or moist static energy), and hence the evolution of the wave. Conversely, convectively-coupled gravity waves arise when anomalous convection eliminates the moisture anomalies more rapidly than dry gravity waves can adjust the troposphere towards WTG balance, causing temperature to govern the moist enthalpy distribution and evolution. Spectral analysis of reanalysis data indicates that slowly-propagating waves (cp ~ 3 m s-1) are likely to be moisture modes while fast waves (cp ~ 30 m s-1) exhibit gravity wave behavior, with "mixed moisture-gravity" waves existing in between. While these findings are obtained from a highly idealized framework, it is hypothesized that they can be extended to understand simulations of convectively-coupled waves in GCMs and the thermodynamics of more complex phenomena.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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