4,536 research outputs found
Attachment priming and avoidant personality features as predictors of social-evaluation biases
Personality research has shown that negativity in social situations (e.g., negative evaluations of others) can be reduced by the activation of participants' sense of attachment security. Individuals with avoidant personality disorder (APD), however, are theoretically less responsive to context or situational cues because of the inflexible nature of their personality disposition. This idea of individual differences in context-responsiveness was tested in a sample of 169 undergraduates who were assessed for APD features and assigned to positive, negative, or neutral attachment priming conditions. More pronounced APD features were associated with more negative responses to vignettes describing potentially distressing social situations. A significant interaction showed that participants with more avoidant features consistently appraised the vignettes relatively more negatively, regardless of priming condition. Those without APD features, by contrast, did not exhibit negative appraisals/evaluations unless negatively primed (curvilinear effect). This effect could not be explained by depression, current mood, or attachment insecurity, all of which related to negative evaluative biases, but none of which related to situation inflexibility. These findings provide empirical support for the notion that negative information-processing is unusually inflexible and context-unresponsive among individuals with more pronounced features of APD
Context effects on second-language learning of tonal contrasts.
Studies of lexical tone  learning generally focus on monosyllabic contexts, while reports of phonetic learning benefits associated with input variability are based largely on experienced learners. This study trained inexperienced learners on Mandarin tonal contrasts to test two hypotheses regarding the influence of context and variability on tone  learning. The first hypothesis was that increased phonetic variability of tones in disyllabic contexts makes initial tone  learning more challenging in disyllabic than monosyllabic words. The second hypothesis was that the learnability of a given tone varies across contexts due to differences in tonal variability. Results of a word learning experiment supported both hypotheses: tones were acquired less successfully in disyllables than in monosyllables, and the relative difficulty of disyllables was closely related to contextual tonal variability. These results indicate limited relevance of monosyllable-based data on Mandarin learning for the disyllabic majority of the Mandarin lexicon. Furthermore, in the short term, variability can diminish learning; its effects are not necessarily beneficial but dependent on acquisition stage and other learner characteristics. These findings thus highlight the importance of considering contextual variability and the interaction between variability and type of learner in the design, interpretation, and application of research on phonetic learning
Study of vapor flow into a capillary acquisition device
An analytical model was developed that prescribes the conditions for vapor flow through the window screen of a start basket. Several original submodels were developed as part of this model. The submodels interrelate such phenomena as the effect of internal evaporation of the liquid, the bubble point change of a screen in the presence of wicking, the conditions for drying out of a screen through a combination of evaporation and pressure difference, the vapor inflow rate across a wet screen as a function of pressure difference, and the effect on wicking of a difference between the static pressure of the liquid reservoir and the surrounding vapor. Most of these interrelations were verified by a series of separate effects tests, which were also used to determine certain empirical constants in the models. The equations of the model were solved numerically for typical start basket designs, and a simplified start basket was constructed to verify the predictions, using both volatile and nonvolatile test liquids. The test results verified the trends predicted by the model
Pitch ability as an aptitude for tone learning
Tone languages such as Mandarin use voice pitch to signal lexical contrasts, presenting a challenge for second/foreign language (L2) learners whose native languages do not use pitch in this manner. The present study examined components of an aptitude for mastering L2 lexical tone. Native English speakers with no previous tone language experience completed a Mandarin word learning task, as well as tests of pitch ability, musicality, L2 aptitude, and general cognitive ability. Pitch ability measures improved predictions of learning performance beyond musicality, L2 aptitude, and general cognitive ability and also predicted transfer of learning to new talkers. In sum, although certain nontonal measures help predict successful tone learning, the central components of tonal aptitude are pitch-specific perceptual measures
History of Mammal Study in Iowa
The first records of mammals in Iowa were from explorers, survey parties heading westward and early seeders. Generation of checklists of state mammals began in 1840 and culminated with the annotated list by Scott (1937) and biogeographic analysis by Bowles (1975). Recent focus has been on rare species status and mammalian ecology, e.g., Loess Hills, riparian habitat, agricultural practices, and reestablished grasslands
Universal Localizations of Certain Noncommutative Rings
A common theme throughout algebra is the extension of arithmetic systems to ones over which new equations can be solved. For instance, someone who knows only positive numbers might think that there is no solution to x + 3 = 0, yet later learns x = ‚à Ã3 to be a feasible solution. Likewise, when faced with the equation 2x = 3, someone familiar only with integers may declare that there is no solution, but may later learn that x = 3/2 is a reasonable answer. Many eventually learn that the extension of real numbers to complex numbers unlocks solutions to previously unsolvable equations, such as x2 = ‚à Ã1.
In algebra, a ring is, roughly speaking, any arithmetic system in which addition and multiplication behave “reasonably”, while a homomorphism is a function that is compatible with the appropriate arithmetic systems. Some rings are noncommutative, meaning that the order in which one multiplies may change the product (i.e.ab ≠ba), in contrast to most grade school arithmetic.
The extension of integers to rational numbers that allows one to solve 2x = 3 is an example of a more general technique, called localization. For commutative rings, localization is well understood and allows one to reasonably form fraction-like objects with numerators and denominators so that one can solve any equation of the form ax = b. However, this process becomes much more difficult for noncommutative rings. A modern perspective on this problem asks more broadly for an extension of a noncommutative ring which makes any given homomorphism invertible, making it possible to solve certain equations involving the homomorphism. In general, satisfactory descriptions for extensions of this type are elusive. However, there are circumstances in which it is possible to give a concrete answer.
We investigate a class of rings called the generalized triangular matrix rings whose elements are matrix-like. Our study focuses on homomorphisms whose inputs and outputs are each columns from these matrices. The results explicitly describe all of the extensions that result in available inverse homomorphisms. These extensions, called universal localizations of the ring, are also rings whose elements are matrix-like, and these matrices are more symmetric than the ring before localization. To provide some historical context, we also recount the developments in the theory that led to this research. This includes detailed descriptions of classical localization and its counterpart in noncommutative algebra, Ore localization, as well as accounts of modern viewpoints, namely Cohn localization and universal adjunction
Heterogeneous condensation of the Lennard-Jones vapor onto a nanoscale seed particle
The heterogeneous condensation of a Lennard-Jones vapor onto a nanoscale seed
particle is studied using molecular dynamics simulations. Measuring the
nucleation rate and the height of the free energy barrier using the mean first
passage time method shows that the presence of a weakly interacting seed has
little effect on the work of forming very small cluster embryos but accelerates
the rate by lowering the barrier for larger clusters. We suggest that this
results from a competition between the energetic and entropic features of
cluster formation in the bulk and at the heterogeneity. As the interaction is
increased, the free energy of formation is reduced for all cluster sizes. We
also develop a simple phenomenological model of film formation on a small seed
that captures the general features of the nucleation process for small
heterogeneities. A comparison of our simulation results with the model shows
that heterogeneous classical nucleation theory provides a good estimate of the
critical size of the film but significantly over-estimates the size of the
barrier.Comment: 9 pages, 10 figures, In Print J. Chem. Phy
Movement of Moose South of Traditional Range in the Upper Midwestern United States
There have been several recent records of moose in southern Minnesota and Iowa, south of their traditional range. Additionally, a bull moose from southern Minnesota crossed Iowa in a southeasterly direction and entered northeastern Missouri, traveling a distance of about 900 km
Developed liquid film passing a smoothed and wedge-shaped trailing edge: small-scale analysis and the ‘teapot effect’ at large Reynolds numbers
Recently, the authors considered a thin steady developed viscous free-surface flow
passing the sharp trailing edge of a horizontally aligned flat plate under surface tension
and the weak action of gravity, acting vertically, in the asymptotic slender-layer limit
(J. Fluid Mech., vol. 850, 2018, pp. 924–953). We revisit the capillarity-driven short-scale
viscous–inviscid interaction, on account of the inherent upstream influence, immediately
downstream of the edge and scrutinise flow detachment on all smaller scales. We adhere to
the assumption of a Froude number so large that choking at the plate edge is insignificant
but envisage the variation of the relevant Weber number of O(1). The main focus, tackled
essentially analytically, is the continuation of the structure of the flow towards scales much
smaller than the interactive ones and where it no longer can be treated as slender. As
a remarkable phenomenon, this analysis predicts harmonic capillary ripples of Rayleigh
type, prevalent on the free surface upstream of the trailing edge. They exhibit an increase
of both the wavelength and amplitude as the characteristic Weber number decreases.
Finally, the theory clarifies the actual detachment process, within a rational description of
flow separation. At this stage, the wetting properties of the fluid and the microscopically
wedge-shaped edge, viewed as infinitely thin on the larger scales, come into play. As this
geometry typically models the exit of a spout, the predicted wetting of the wedge is related
to what in the literature is referred to as the teapot effect
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