The nose in leprosy: immunohistology of the nasal mucosa

The alignment of single-particle images fails at low signal-to-noise ratios and small particle sizes, because noise produces false peaks in the cross-correlation function used for alignment. A maximum-likelihood approach to the two-dimensional alignment problem is described which allows the underlying structure to be estimated from large data sets of very noisy images. Instead of finding the optimum alignment for each image, the algorithm forms a weighted sum over all possible in-plane rotations and translations of the image. The weighting factors, which are the probabilities of the image transformations, are computed as the exponential of a cross-correlation function. Simulated data sets were constructed and processed by the algorithm. The results demonstrate a greatly reduced sensitivity to the choice of a starting reference, and the ability to recover structures from large data sets having very low signal-to-noise ratios.     

Seismic Vulnerability and Mitigation during Construction of Cable-Stayed Bridges

The implications of earthquake loading during balanced cantilever construction of a cable-stayed bridge are examined. Finite-element models of a cable-stayed bridge were developed and multiple ground motion time history records were used to study the seismic response at the base of the towers for six stages of balanced cantilever construction. Probabilistic seismic hazard relationships were used to relate ground motions to bridge responses. The results show that there can be a high probability of having seismic responses (forces/moments) in a partially completed bridge that exceed, often by a substantial margin, the 10%/50-year design level (0.21% per annum) for the full bridge. The maximum probability of exceedance per annum was found to be 20%. This occurs because during balanced-cantilever construction the structure is in a particularly precarious and vulnerable state. The efficacy of a seismic mitigation strategy based on the use of tie-down cables intended for aerodynamic stability during construction was investigated. This strategy was successful in reducing some of the seismic vulnerabilities so that probabilities of exceedance during construction dropped to below 1% per annum. Although applied to only one cable-stayed bridge, the same approach can be used for construction-stage vulnerability analysis of other long-span bridges.     

Spatial attention and response control in healthy younger and older adults and individuals with Alzheimer's disease: Evidence for disproportionate selection impairments in the simon task.

The authors examined the degree to which aging and Alzheimer's disease (AD) influence the ability to control attention when conflict is presented in terms of incongruent mapping between a stimulus and the appropriate response. In a variant of the Simon task, healthy older adults and older adults with mild or very mild AD showed disproportionately larger reaction time (RT) costs when the stimulus and response were in conflict relative to RT costs of healthy younger adults. Analyses of RT distributions provide support for a 2-process model of the Simon effect in which there is a short-lived transient effect of the irrelevant dimension in younger adults and a more sustained influence across the RT distribution in older adults. An analysis of error rates showed that the older adults with mild and very mild AD made more errors on incongruent trials, suggesting that AD leads to increased likelihood of selecting the prepotent pathway. The findings are discussed in terms of the special nature of the response requirements of the Simon task to better illuminate the attentional decrements in both healthy aging and early stage AD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading and the corpus callosum: An MRI family study of volume and area.

This study examines the corpus callosum in 68 readers nested in 24 families. Callosa were measured and controlled for whole brain volume, intelligence, and gender. The relation of corpus callosum size to the within-family variance of oral reading was investigated with various measurements: volume, midsagittal area, and anterior-to-posterior one-fifth area segmentations. Because this is the first known publication of MRI calculations of corpus callosum volume, some basic questions about bilateral symmetry and the efficacy of area versus volumetric measurements were explored. Results suggest that better readers within families have larger midsagittal areas at the midbody. Although reliably measured, volume did not contribute to oral reading but was highly correlated with area. Bilateral volumes of the corpus callosum were symmetric. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do readers obtain preview benefit from word n + 2? A test of serial attention shift versus distributed lexical processing models of eye movement control in reading.

Two experiments tested predictions derived from serial lexical processing and parallel distributed models of eye movement control in reading. The boundary paradigm (K. Rayner, 1975) was used, and the boundary location was set either at the end of word n - 1 (the word just to the left of the target word) or at the end of word n - 2. Serial lexical processing models predict that there should be preview benefit only when the boundary is set at word n - 1 (when the target word will be the next word fixated) and no preview benefit when the boundary is set at word n - 2. Parallel lexical models, on the other hand, predict that there should be some preview benefit in both situations. Consistent with the predictions of the serial lexical processing models, there was no preview benefit for a target word when the boundary was set at the end of word n - 2. Furthermore, there was no evidence of parafoveal-on-foveal effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Couples Emotion Rating Form: Psychometric properties and theoretical associations.

The Couples Emotion Rating Form assesses 3 types of negative emotion that are salient during times of relationship conflict. Hard emotion includes feeling angry and aggravated, soft emotion includes feeling hurt and sad, and flat emotion includes feeling bored and indifferent. In Study 1, scales measuring hard and soft emotion were validated by observation of 82 married couples in a series of conflict conversations. Self-report ratings for each emotion corresponded with observer ratings of the same emotion, and the emotion scales produced expected correlations with negative affect. In Study 2, a measure of flat emotion was added to the instrument, and 1,239 married people completed questionnaires. The rating form fit an expected 3-dimensional factor structure, and each scale correlated with a set of theoretically linked constructs. Hard emotion was associated with power assertion, pursuit of self-centered goals, and negative communication. Soft emotion was associated with expressions of vulnerability, pursuit of prosocial goals, and positive communication. Flat emotion was distinct from other emotions in being associated with withdrawal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of attention problems on depression: Developmental, academic, and cognitive pathways.

The present study investigated developmental pathways between inattention and depression, particularly the roles of school maladjustment and child cognitions. Additionally, a measure of conduct problems was included in all analyses to test competing theories about the emergence of depressive symptoms. Results supported the hypothesized path models from inattention to depression for younger and older children. Consistent with developmental theories, only an environmental variable, school maladjustment, was needed to explain the relationship between inattention and depression for the younger group (under 8 years old). For children in the middle group (8-9 years old), school maladjustment continued to uniquely account for part of the path to child depressive symptoms, but a cognitive variable, control-related beliefs, emerged as a significant mediator as well. For older children (10 years and older), control-related beliefs fully mediated the effects of school maladjustment on depressive symptoms. The hypothesized paths from conduct problems to depression, however, were not supported. Implications for designing interventions and prevention strategies for children with inattention and conduct problems are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging effects on microstructural and mechanical properties of select refractory metal alloys for space-reactor applications

Refractory alloys based on niobium, tantalum and molybdenum are potential candidate materials for structural applications in proposed space nuclear reactors. Long-term microstructural stability is a requirement of these materials for their use in this type of creep dominated application. Early work on refractory metal alloys has shown aging embrittlement occurring for some niobium and tantalum-base alloys at temperatures near 40% of their melting temperatures in either the base metal or in weldments. Other work has suggested microstructural instabilities during long-term creep testing, leading to decreased creep performance. This paper examines the effect of aging 1100 h at 1098, 1248 and 1398 K on the microstructural and mechanical properties of two niobium (Nb-1Zr and FS-85), tantalum (T-111 and ASTAR-811C) and molybdenum (Mo-41Re and Mo-47.5Re) base alloys. Changes in material properties are examined through mechanical tensile testing coupled with electrical resistivity changes and microstructural examination through optical and electron microscopy analysis.     

A prospective study of short- and long-term outcomes after traumatic brain injury in children: Behavior and achievement.

Longitudinal behavior and achievement outcomes of traumatic brain injury (TBI) were investigated in 53 children with severe TBI, 56 children with moderate TBI, and 80 children with orthopedic injuries not involving brain insult. Measures of preinjury child and family status and of postinjury achievement skills were administered shortly after injury. Assessments were repeated 3 times across a mean follow-up interval of 4 years. Results from mixed model analysis revealed persisting sequelae of TBI. Recovery of math skills was observed in the severe TBI group but only for children from less stressed families. Social disadvantage in children with TBI predicted more adverse behavioral sequelae and less favorable changes in some outcome measures. The findings suggest that pediatric TBI has long-term effects on behavior and achievement but that postinjury progress is influenced by the family environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Linking sportfishing trip attributes,participation decisions,and regional economic impacts in Lower and Central Cook Inlet,Alaska

Forecasts of the regional economic impacts of changes in the demand for recreation occasioned by regulatory changes, changes in the quality of the recreation experience, or changes in average trip costs require a model that links changes in these trip attributes to individual participation decisions and population participation rates. The probability that an individual will take a particular recreational trip is described using a nonlinear random effects probit model based on variable trip attributes and individual economic and demographic characteristics. These conditional individual probabilities are transformed into predictions of changes in total recreation demand using a simulation-based sample enumeration method. The regional impacts associated with ensuing changes in primary and secondary expenditure patterns are elucidated with a stand-alone recreation-sector module linked to a regionally adjusted zip code-level input-output model. Because the participation model allows for non-constant marginal utility, primary and secondary impacts exhibit nonlinear responses to variations in trip attributes. The modeling approach is demonstrated in an application to the saltwater sport fisheries for Pacific halibut and salmon in Lower and Central Cook Inlet, Alaska. Received: February 2001/Accepted: December 2001