Stabilization of the retinal image: A review of method, effects, and theory.

A summary is presented of 3 basic methods used in reducing or stopping involuntary eye movements in order to produce a stable retinal image. This stabilization produces some degree of fading or disappearance of the target being viewed. Additional effects on such factors as acuity and contrast thresholds are considered, as well as the effects of such variables as exposure time, flicker, attention, meaning, and target complexity on the nature and extent of target disappearance. Some explanations for the phenomenon are presented, and the theoretical implications of invariant stimulation on the perceptual process are discussed. (39 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Formation and maintenance of the myelin sheath in the peripheral nerve: roles of cell adhesion molecules and the gap junction protein connexin 32

Based on previous in vitro studies, the cell adhesion molecules L1, N-CAM, MAG, and P0, which all belong to the immunoglobulin (Ig)-superfamily, have been suggested to mediate myelin formation in the peripheral nervous system. Unexpectedly, studies in mice deficient for the corresponding molecules revealed that only P0 plays pivotal roles during the formation of peripheral nerve myelin in vivo, while L1-, N-CAM-, and MAG-deficient mice develop myelin of normal ultrastructure. However, MAG turned out to be important for the maintenance of myelin, as reflected by degeneration of myelin and axons in MAG-deficient mice older than 6 months. The MAG-mediated maintenance of myelin is backed up by N-CAM, since mice deficient in both MAG and N-CAM show an earlier and more prominent myelin degeneration than MAG single mutants. Another peripheral nerve component involved in the maintenance of myelinated fibers is connexin 32 (Cx32), a gap junction channel protein that does not belong to the Ig-superfamily. Mice deficient in Cx32 initially form normal myelin, which then develops blown-up periaxonal collars and abnormally shaped non-compacted regions followed by myelin and axonal degeneration. Our findings strongly support the view that very few myelin components are necessary for myelin formation whereas the maintenance of myelin is much more sensitive to molecular alterations. In addition, it became evident that myelin molecules can fulfill functionally overlapping roles that ensure that myelination takes place even under conditions in which there is a deficiency in the normal molecular components of myelin.     

Automated image registration: I. General methods and intrasubject, intramodality validation

The question of whether bees can take novel short cuts between familiar sites has been central to the discussion about the existence of cognitive maps in these insects. The failure of bees to show this capacity in the majority of previous studies may be a result of the training procedure, because extensive training to one feeding site may have eliminated or weakened memories for other sites that were previously trained. Here we present a novel approach to this problem, by rewarding honey bees, Apis mellifera carnica, at two feeding sites, one (Sm, 630 m southeast from the hive) at which they could feed in the morning, and the other (Sa, 790 m northeast) at which they could feed in the afternoon. We then displaced bees to Sa in the morning and to Sm in the afternoon either from the other feeding site or from the hive. Bees were also displaced to two novel sites, one at a completely unfamiliar location (S4) and another that was located halfway between the two feeding sites (S3). Bees displaced from either of the feeding sites never took novel short cuts; instead, they used the homeward directions that would have been correct had they not been displaced. Bees caught at the hive entrance, however, chose the correct homeward direction not only when displaced to both feeding sites, but also when displaced to S3, although not from S4. Control bees that had been trained to only one of the feeding sites were not able to travel directly home from S3 excluding the possibility that bees used landmarks close to the hive. This is the first evidence that bees take a novel short cut by activating two vector memories simultaneously. The potential mechanisms of integrating the two memories are discussed. Since bees took novel short cuts in only one direction (to the hive) and only when displaced from the hive (not the feeders), we conclude that inference of a cognitive map in bees would be premature. Copyright 1998 The Association for the Study of Animal Behaviour.     

Quantification of eumelanin and pheomelanin: stereologic image analysis method

Chemical antioxidants and catalase have been shown to be ineffective in improving the motility of ram spermatozoa in a chemically-defined diluent (RSD-1). In an attempt to identify the biochemical basis of this observation, the activity of aromatic amino acid oxidase (AAAO), the enzyme responsible for generation of hydrogen peroxide in ram and bull spermatozoa, has been investigated. Ram spermatozoa contained higher levels of AAAO activity than bull spermatozoa, although the physico-chemical properties of the enzyme were generally similar in both species. Components of the medium had a marked effect upon AAAO activity. In the presence of glutamate and 3-(N-morpholino)propanesulfonic acid (MOPS), AAAO activity was decreased. Pyruvate appeared to increase AAAO activity. This was due to the ability of this substance to destroy hydrogen peroxide. Pyruvate in RSD-1 works as an effective antioxidant and therefore eliminates the need for other antioxidants in the semen diluent.     

Prediction of long-term polyethylene wear in total hip arthroplasty, based on early wear measurements made using digital image analysis

We present five cases of a hitherto unreported cutaneous neoplasm. The tumors appeared as solitary slow-growing flesh-colored nodules arising in young and middle-aged adults. They were located on the trunk, the upper extremities, and the face, and did not recur after complete excision. Clinically, they were diagnosed as dermal nevus, Spitz's nevus, fibroma, or neurofibroma. Histology revealed polypoid flat-dome-shaped lesions with a sharply demarcated matrix consisting of coarse hyalinized collagen bundles arranged in a prominent storiform pattern and separated by mucin-containing clefts. Despite a low overall cellularity, the tumors contained numerous, occasionally bizarre-shaped, multinucleate giant cells with crowded vesicular nuclei and a pale staining foamy cytoplasm, as well as plump fibroblastlike cells with analogous nuclear morphology. Atypical nuclei or mitotic figures were not observed. The cells were strongly positive for vimentin but negative for cytokeratin, smooth muscle actin, desmin, S-100 protein, CD34, factor XIIIa, and the macrophage markers KP1, Mac 387, and Ki-M1p, suggesting a fibroblastic origin. Based on the overall architecture, we conclude that these tumors probably represent a distinctive variant of solitary circumscribed storiform collagenoma (sclerotic fibroma) and propose the designation of giant cell collagenoma.     

Computer analysis of mammography phantom images (CAMPI): an application to the measurement of microcalcification image quality of directly acquired digital images

The purpose of this investigation was to apply the recently developed CAMPI (computer analysis of mammography phantom images) method to a Fischer Mammotest Stereotactic Digital Biopsy machine. Another aim was to further elucidate the nature of the empirically introduced CAMPI measures. Images of an American College of Radiology (ACR) accreditation phantom centered on the largest two speck groups were obtained on this machine under a variety of x-ray conditions. An additional measure, alternative SNR (ASNR) is introduced which is complementary to the SNR measure. Analyses of the Mammotest images revealed that the mAs and kVp dependencies of the CAMPI measures could be understood from basic imaging physics principles. It is shown that: (1) the measures reflect the expected linearity of the digital detector and Poisson photon statistics; (2) under automatic exposure control (AEC) conditions the signal (SIG) measure is proportional to subject contrast; and (3) under AEC conditions the noise (NOI) measure is proportional to the square root of the average absorbed photon energy. Correspondence with basic imaging physics principles shows that the measures are significantly free of artifacts. Precision of the CAMPI measures exceeds that of human observers by orders of magnitude. CAMPI measures are expected to be more relevant to clinical mammography than Fourier metrics as the measurements are done on objects of arbitrary shape and size that were designed by the manufacturer to resemble various detection tasks in mammography. It is concluded that CAMPI can perform objective and highly precise evaluations of phantom image quality in mammography. It could be used as a sophisticated quality control tool, as a replacement for the current ACR/MQSA phantom evaluation program, and to evaluate the rapidly evolving digital mammography technology.     

The structure and dynamics of worry: theory, measurement, and cross-national replications

This article presents a comprehensive conceptualization of the structure of worry and the relation of worry to mental health and well-being. It is assumed that worries have two facets, namely, the object of a worry (e.g., self, close others, society, the world) and the domain of a worry (the field of life with which it is concerned). The object of a worry is presumed to be more important than its domain in determining the impact of worries on mental health. Only worries concerned with self and close others (micro worries) are expected to be related to poor mental health, whereas worries about society or the entire world (macro worries) are expected to be positively related to mental health. An instrument is introduced to study worries in accordance with the proposed structure. Its validity is tested by two confirmatory techniques (similarity structure analysis and confirmatory factor analysis) in samples from Israel, West Germany, and (the former) East Germany. Worry scores are also related to five mental health indicators. Results show that across samples micro and macro worries can validly be distinguished. Micro worries are strongly related to poor mental health, whereas macro worries are unrelated to mental health or relate marginally to positive well-being.     

Confirmatory factor analysis and item response theory: Two approaches for exploring measurement invariance.

Investigated the utility of confirmatory factor analysis (CFA) and item response theory (IRT) models for testing the comparability of psychological measurements. Both procedures were used to investigate whether mood ratings collected in Minnesota and China were comparable. Several issues were addressed. The 1st issue was that of establishing a common measurement scale across groups, which involves full or partial measurement invariance of trait indicators. It is shown that using CFA or IRT models, test items that function differentially as trait indicators across groups need not interfere with comparing examinees on the same trait dimension. Second, the issue of model fit was addressed. It is proposed that person-fit statistics be used to judge the practical fit of IRT models. Finally, topics for future research are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perineurial malignant peripheral nerve sheath tumor (MPNST): a clinicopathologic, immunohistochemical, and ultrastructural study of seven cases

Most malignant peripheral nerve sheath tumors (MPNST) are schwannian in nature. The pathologic features of MPNST with perineurial cell differentiation remain to be characterized. To determine the clinicopathologic, immunohistochemical, and ultrastructural characteristics of perineurial MPNST, 121 MPNST from the Mayo Clinic Tissue Registry were examined. Of these 23 spindle cell tumors with long processes disposed in whorls or storiform patterns, features typical of perineurioma, were studied. On the basis of immunohistochemistry (epithelial membrane antigen+/S-100-), 5 perineurial MPNST were identified among 23 tumors selected. These and two previously characterized perineurial MPNST are the subject of this study. None of seven tumors was associated with NF-1. Patients included five males and two females ranging in age from 11 to 83 years (mean, 45.7 years). The tumors measured 1.5 to 30 cm (mean, 9.1 cm) and arose in the extremities (two), trunk (two), face (one), mediastinum (one), and retroperitoneum (one). Only one tumor was nerve associated (phrenic nerve). All tumors were surgically removed. No encapsulation or neurofibroma components were noted. Necrosis was seen in three lesions. Four tumors were classified as high-grade malignant and three as low grade. Mitotic indices varied from 1 to 85/10 high-power fields (median, 16). Immunoreactivities included epithelial membrane antigen (100%), vimentin (100%), Leu-7 (57%), and CD34 (14%). Stains for S-100 protein, muscle markers, and cytokeratin were nonreactive. Ultrastructurally, perineurial-like cells were noted in three tumors and cells intermediate between perineurial and Schwann cells in one. Four tumors recurred and two metastasized; no deaths of disease were noted at follow-ups of 28 to 98 months (mean, 66.9). In conclusion, 4% of MPNST show perineurial cell differentiation. An NF-1 association has yet to be described. Nerve involvement is infrequent. Their immunophenotype (epithelial membrane antigen+/S-100-) frequently indicates ultrastructural perineurial differentiation. The prognosis of perineural MPNST appears to be more favorable than that of conventional MPNST.     

喷射成形时雾化压力与静压头对雾化熔滴尺寸影响的理论分析

本文建立了静压头、雾化压力与雾化熔滴尺寸的模型关系。雾化压力一定，雾化熔滴质量中值直径随静压头的减小而减小；静压头一定。雾化熔滴尺寸随着雾化压力的增加而减小。通过模型，调节雾化压力以适应静压头变化引起的金属液体质量流率变化，以期得到具有合适尺寸的雾化熔滴，优化沉积坯组织。     

Amygdala size and hypothalamus size predict social play frequency in nonhuman primates: A comparative analysis using independent contrasts.

The amygdala and hypothalamus become sexually differentiated by gonadal hormones giving rise to sexually differentiated behaviors, which include play behavior. Phylogenetic comparative analyses test for relationships between social play and brain structure volumes. Relative volume of the amygdala and hypothalamus correlated with social play, but not nonsocial play, even after controlling for the size of other brain structures. The authors propose that behaviors such as social assessment, recognizing and responding to facial expression, and social response appropriateness, which are mediated by the amygdala, are developed through social play. Additionally, the hypothalamus may regulate the motivation to engage in play through positive reinforcement of pleasurable activity. Thus, the instinctive socioemotive aspects of play in primates appear to be those regulated by the amygdala and hypothalamus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Framing, cognitive modes, and image theory: Toward an understanding of a glass half full.

Data from 2 experiments indicate that information framing affects decision episodes in more ways than previous studies showed. Results suggest that framing biases problem-space perceptions and may act as a catalyst for different modes of cognitive processing. Characteristics of controlled cognitive modes were found when information was negatively framed; characteristics of more automatic processing were found when information was positively framed. Results from the 2nd experiment also suggest that the emergence of these cognitive differences could be due to the effect of framing on a decision maker's perception of project images. Positive framing was associated with perception of compatibility between current and trajectory project images; negative framing was related to perceptions of greater image incompatibility. Implications for theory and practice are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Racial and ethnic identity theory, measurement, and research in counseling psychology: Present status and future directions.

The present article integrates and expands on the special section contributions of K. O. Cokley (2007); J. E. Helms (2007); J. E. Trimble (2007); S. M. Quintana (2007); and J. S. Phinney and A. D. Ong (2007). The authors of the present article begin with a note on politics and ideology in writings on racial identity development and review general progress the field has made on the topics of racial and ethnic identity development. The present challenges in both explicating clear and concise theories of racial and ethnic identity development and operationalizing and measuring these constructs in paper-and-pencil form are identified. The need for interdisciplinary work on theory testing is highlighted, and select examples of best practices in measuring racial and ethnic identity are presented. The article closes with directions for research in racial and ethnic identity development, and with implications for counseling practice, supervision, and systemic change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect size estimation for one-sample multiple-choice-type data: Design, analysis, and meta-analysis.

This article proposes a standard, easy-to-interpret effect size estimate for one-sample research. The proportion index (π) shows the hit rate on a scale on which .50 is always the null value regardless of the number of equally likely choices. The index π is useful in the design of one-sample research because it can guide the best choice of number of response alternatives. Significance tests and confidence limits are readily computed. For meta-analyses of one-sample studies, tests of heterogeneity of a set of πs and contrasts among them are described. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three approaches to the investigation of subgroup bias in performance measurement: Review, results, and conclusions.

Three methods of assessing subgroup bias in performance measurement commonly found in the literature are identified. After a review of these approaches, findings are reported from analyses of data collected in the US Army's Project A (J. P. Campbell, 1987). Correlations between nonrating performance measures and supervisor ratings were generally not moderated by race, but correlations between nonrating indicators of negative performance and ratings assigned by peers were. In addition, significant interactions between rater and ratee race on performance ratings were not eliminated when variance in the nonrating measures was removed from the ratings provided by Black and White raters. Conclusions about the magnitude and nature of bias in supervisor and peer ratings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Three-dimensional CT measurement of adult acetabular dysplasia: technique, preliminary results in normal subjects, and potential applications

OBJECTIVE: To assess a three-dimensional computed tomography (3DCT) technique for measurement of acetabular coverage in adults. DESIGN: We used 3DCT to define the geometric centre of the femoral head and to measure centre-edge angles (CEAs) at 10 degrees rotational increments around the acetabular rim. The means, ranges, standard deviations and 95% confidence intervals for the CEAs at the various rotational increments were determined. Inter- and intra-observer variability was measured. The normal values are compared with two example cases of acetabular dysplasia. PATIENTS: The normal hips of 15 subjects aged 1949 years (mean 34.2 years) were measured. RESULTS: The 3DCT measurements are reproducible (mean difference interobserver, 1.7 degrees - 7.9 degrees; mean difference intra-observer, 0.6 degrees-6.9 degrees). Mean normal CEA at the lateral rim was 33 degrees with a 95% confidence interval of 23 degrees - 43 degrees. Mean normal CEAs at 10 rotational increments from anterior to posterior rim were determined, and graphed as a 'normal curve'. CONCLUSION: This new 3DCT method of assessing acetabular dysplasia is simple, reproducible, and applicable to diagnosis, quantification and surgical planning for adult acetabular dysplasia patients.     

Personality measurement, faking, and detection: An assessment method for use in personnel selection.

Usual methods for personality assessment have been found unsuitable for use in personnel selection contexts. An alternative method of item construction and of scoring key and detection scale development for personality inventories is proposed. Results of a double cross-validation study based on 456 male Ss using 3 newly developed forced-choice inventories indicate that (a) over 90% of the test performance can be correctly identified as self-report or faked, (b) mean score profiles under the 2 conditions for the 5 personality variables under study are virtually congruent and variances under the faking condition are uniformly smaller, (c) validities against peer-nomination criteria are in the moderate range for all 5 variables and (d) Kuder-Richardson Formula 20 reliabilities between .83 and .92 were obtained. (27 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)