621 research outputs found
Acoustic Correlates and Adult Perceptions of Distress in Infant Speech-Like Vocalizations and Cries
Prior research has not evaluated acoustic features contributing to perception of human infant vocal distress or lack thereof on a continuum. The present research evaluates perception of infant vocalizations along a continuum ranging from the most prototypical intensely distressful cry sounds (āwailsā) to the most prototypical of infant sounds that typically express no distress (non-distress āvocantsā). Wails are deemed little if at all related to speech while vocants are taken to be clear precursors to speech. We selected prototypical exemplars of utterances representing the whole continuum from 0 and 1 month-olds. In this initial study of the continuum, our goals are to determine (1) listener agreement on level of vocal distress across the continuum, (2) acoustic parameters predicting ratings of distress, (3) the extent to which individual listeners maintain or change their acoustic criteria for distress judgments across the study, (4) the extent to which different listeners use similar or different acoustic criteria to make judgments, and (5) the role of short-term experience among the listeners in judgments of infant vocalization distress. Results indicated that (1) both inter-rater and intra-rater listener agreement on degree of vocal distress was high, (2) the best predictors of vocal distress were number of vibratory regimes within utterances, utterance duration, spectral ratio (spectral concentration) in vibratory regimes within utterances, and mean pitch, (3) individual listeners significantly modified their acoustic criteria for distress judgments across the 10 trial blocks, (4) different listeners, while showing overall similarities in ratings of the 42 stimuli, also showed significant differences in acoustic criteria used in assigning the ratings of vocal distress, and (5) listeners who were both experienced and inexperienced in infant vocalizations coding showed high agreement in rating level of distress, but differed in the extent to which they relied on the different acoustic cues in making the ratings. The study provides clearer characterization of vocal distress expression in infants based on acoustic parameters and a new perspective on active adult perception of infant vocalizations. The results also highlight the importance of vibratory regime segmentation and analysis in acoustically based research on infant vocalizations and their perception
Mobile air monitoring data-processing strategies and effects on spatial air pollution trends
The collection of real-time air quality measurements while in motion (i.e.,
mobile monitoring) is currently conducted worldwide to evaluate in situ
emissions, local air quality trends, and air pollutant exposure. This
measurement strategy pushes the limits of traditional data analysis with
complex second-by-second multipollutant data varying as a function of time
and location. Data reduction and filtering techniques are often applied to
deduce trends, such as pollutant spatial gradients downwind of a highway.
However, rarely do mobile monitoring studies report the sensitivity of their
results to the chosen data-processing approaches. The study being reported
here utilized 40 h (> 140 000 observations) of mobile monitoring data
collected on a roadway network in central North Carolina to explore common
data-processing strategies including local emission plume detection,
background estimation, and averaging techniques for spatial trend analyses.
One-second time resolution measurements of ultrafine particles (UFPs), black
carbon (BC), particulate matter (PM), carbon monoxide (CO), and nitrogen
dioxide (NO<sub>2</sub>) were collected on 12 unique driving routes that were
each sampled repeatedly. The route with the highest number of repetitions was
used to compare local exhaust plume detection and averaging methods. Analyses
demonstrate that the multiple local exhaust plume detection strategies
reported produce generally similar results and that utilizing a median of
measurements taken within a specified route segment (as opposed to a mean)
may be sufficient to avoid bias in near-source spatial trends. A time-series-based method of estimating background concentrations was shown to produce
similar but slightly lower estimates than a location-based method. For the
complete data set the estimated contributions of the background to the mean
pollutant concentrations were as follows: BC (15%), UFPs (26%), CO (41%),
PM<sub>2.5-10</sub> (45%), NO<sub>2</sub> (57%), PM<sub>10</sub> (60%), PM<sub>2.5</sub>
(68%). Lastly, while temporal smoothing (e.g., 5 s averages) results
in weak pair-wise correlation and the blurring of spatial trends, spatial
averaging (e.g., 10 m) is demonstrated to increase correlation and refine
spatial trends
A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust
This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental group\u27s trust in water regulatory institutions was less affected by fluctuations of trustworthiness (but not distrustworthiness) perceptions over time. This suggests that knowledge results in the development of more stable institutional trust attitudes, but that trustworthiness and distrustworthiness perceptions may operate somewhat differently when impacting trust in specific institutions
A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust
This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental group\u27s trust in water regulatory institutions was less affected by fluctuations of trustworthiness (but not distrustworthiness) perceptions over time. This suggests that knowledge results in the development of more stable institutional trust attitudes, but that trustworthiness and distrustworthiness perceptions may operate somewhat differently when impacting trust in specific institutions
The Supply Side Determinants of Territory and Conflict
What determines the geographic extent of territory? We microfound and extend Bouldingās āLoss of Strength Gradientā to predict the extensive and intensive margins of conflict across space. We show how economies of scale in the production of violence and varying costs of projecting violence at a distance combine to affect the geographic distribution of conflict and territory. We test and probe the boundaries of this model in an experiment varying the fixed costs of conflict entry. As predicted, higher fixed costs increase the probability of exclusive territories; median behavior closely tracks equilibrium predictions in all treatments
Tipping Points for Norm Change in Human Cultures
Humans interact with each other on a daily basis by developing and
maintaining various social norms and it is critical to form a deeper
understanding of how such norms develop, how they change, and how fast they
change. In this work, we develop an evolutionary game-theoretic model based on
research in cultural psychology that shows that humans in various cultures
differ in their tendencies to conform with those around them. Using this model,
we analyze the evolutionary relationships between the tendency to conform and
how quickly a population reacts when conditions make a change in norm
desirable. Our analysis identifies conditions when a tipping point is reached
in a population, causing norms to change rapidly.Comment: SBP-BRiMS 201
Coral geochemical response to uplift in the aftermath of the 2005 NiasāSimeulue earthquake
On 28 March 2005, the Indonesian islands of Nias and Simeulue experienced a powerful Mw 8.6 earthquake and coseismic uplift and subsidence. In areas of coastal uplift (up to ~ā2.8 m), fringing reef coral communities were killed by exposure, while deeper corals that survived were subjected to habitats with altered runoff, sediment and nutrient regimes. Here we present time-series (2000ā2009) of Mn/Ca, Y/Ca and Ba/Ca variability in massive Porites corals from Nias to assess the environmental impact of a wide range of vertical displacement (+ā2.5 m to āā0.4 m). High-resolution LA-ICP-MS measurements show that skeletal Mn/Ca increased at uplifted sites, regardless of reef type, indicating a post-earthquake increase in suspended sediment delivery. Transient and/or long-term increases in skeletal Y/Ca at all uplift sites support the idea of increased sediment delivery. Coral Mn/Ca and Ba/Ca in lagoonal environments highlight the additional influences of reef bathymetry, wind-driven sediment resuspension, and phytoplankton blooms on coral geochemistry. Together, the results show that the Nias reefs adapted to fundamentally altered hydrographic conditions. We show how centuries of repeated subsidence and uplift during great-earthquake cycles along the Sunda megathrust may have shaped the modern-day predominance of massive scleractinian corals on the West Sumatran reefs
- ā¦