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The Item Wording Effect (IWE) in psychological testing describes how individuals respond differently to positively and negatively worded items. Previous IWE research faced challenges due to measures varying beyond item valence. This study aimed to address this problem by developing an inventory, the Positive and Negative Descriptor Inventory (PANDI), with items varying solely on valence. Semantic framing was manipulated to examine which factor (valence vs. framing) was more causal of the IWE. Using an online survey on Mechanical Turk, 336 Canadian participants responded to PANDI items in different experimental conditions. Results indicated that item valence had a bigger impact on IWE than semantic framing. PANDI-Good items in the Affirming Condition exhibited lower reliability but higher means and response variance than other groups, emphasizing the significant difference in how individuals interpret positive and negating inventory items. This study recommends using negatively worded items sparingly, and not using negating items at all. [ABSTRACT FROM AUTHOR]

In Quantum Mechanics and Experience, David Albert sets out to accomplish two tasks. The first is to provide an introduction to some of the conceptual problems of quantum mechanics for [...]

Subseasonal-to-seasonal prediction of winter weather in Europe has seen advances in recent years due to improvements in the ability of ensemble prediction systems to capture signals of the controlling regional atmospheric circulation patterns. Nevertheless, these predictions are still hampered by the 'signal-to-noise paradox', the fact that while ensemble mean signals are relatively well correlated with observed outcomes, the size of these signals is far less than expected given the level of agreement. This makes the predictions less easy to use, requiring additional post-processing to provide best guidance. The issue points to potential shortcomings in the formulation of prediction systems, and likely the representation of climate dynamical processes in their component models. The identity of the source of the paradox, however, has hitherto remained cryptic. One possible diagnostic approach is to perform reforecasts of past cases in which parts of the atmospheric simulation are constrained to be similar to the analysed state of the atmosphere at the time. This allows us to identify whether a 'perfect' representation of a specific atmospheric region improves the signal-to-noise of the North Atlantic atmospheric circulation, and thereby whether the paradox partly results from imperfect simulation of that region. Here we report results from tests using suites of ensemble simulations with the Met Office long-range prediction system in which the tropical atmosphere is constrained by relaxation towards analysed winds and temperatures. The tropics make a worthwhile test since teleconnections with middle and high latitudes have been shown to be an important driver of North Atlantic-European winter circulation anomalies. Any failing in the tropical simulation could therefore be a potential reason for the low signal-to-noise we obtain. The tropical influence can act via either a tropospheric route, involving Rossby wave propagation within the troposphere, or a stratospheric route, via the Quasi-Biennial Oscillation (QBO)'s effect on the stratospheric polar vortex and its subsequent downward influence. In order to separate these potentially distinct sources of the signal-to-noise paradox, we additionally present results from suites of experiments with troposphere and stratospheric relaxation applied individually. [ABSTRACT FROM AUTHOR]

In-situ observations of crystallisation in minerals and organic polymers have been made by simultaneous, time-resolved small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) techniques. In isotactic polypropylene slow quiescent crystallisation shows the onset of large scale ordering prior to crystal growth. Rapid crystallisations studied by melt extrusion indicate the development of well resolved oriented SAXS patterns associated with long range order before the development of crystalline peaks in the WAXS region. Block copolymers self-assemble into mesophases in polymer melts above a critical chain length (or above a critical temperature) and this self-assembly process is shown to be susceptible to an incipient crystallisation. Mesophase formation is observed at anomalously high temperatures in ethylene-oxide containing block copolymers below the normal melting point of the polyoxy ethylene chains. Formation of calcium carbonate from aqueous solutions of sodium carbonate and calcium nitrate is observed to be a two-stage process and precipitation proceeds by the production of an amorphous metastable phase. This phase grows until it is volume filling and leads to the formation of the two polymorphs Calcite and Vaterite. These three sets of results suggest pre-nucleation density fluctuations, leading to a metastable phase, play an integral role in all three classes of crystallisation. In due course, this phase undergoes transformation to "normal" crystals.