Masticatory loadings and cranial deformation in Macaca fascicularis: a finite element analysis sensitivity study

Biomechanical analyses are commonly conducted to investigate how craniofacial form relates to function, particularly in relation to dietary adaptations. However, in the absence of corresponding muscle activation patterns, incomplete muscle data recorded experimentally for different individuals during different feeding tasks are frequently substituted. This study uses finite element analysis (FEA) to examine the sensitivity of the mechanical response of a Macaca fascicularis cranium to varying muscle activation patterns predicted via multibody dynamic analysis. Relative to the effects of varying bite location, the consequences of simulated variations in muscle activation patterns and of the inclusion/exclusion of whole muscle groups were investigated. The resulting cranial deformations were compared using two approaches; strain maps and geometric morphometric analyses. The results indicate that, with bite force magnitude controlled, the variations among the mechanical responses of the cranium to bite location far outweigh those observed as a consequence of varying muscle activations. However, zygomatic deformation was an exception, with the activation levels of superficial masseter being most influential in this regard. The anterior portion of temporalis deforms the cranial vault, but the remaining muscles have less profound effects. This study for the first time systematically quantifies the sensitivity of an FEA model of a primate skull to widely varying masticatory muscle activations and finds that, with the exception of the zygomatic arch, reasonable variants of muscle loading for a second molar bite have considerably less effect on cranial deformation and the resulting strain map than does varying molar bite point. The implication is that FEA models of biting crania will generally produce acceptable estimates of deformation under load as long as muscle activations and forces are reasonably approximated. In any one FEA study, the biological significance of the error in applied muscle forces is best judged against the magnitude of the effect that is being investigated.     

An interfering factor in the automated analysis of calcium.

The widespread use of stainless steel for sample probes, connectors, and sample stream splitters in autoanalyser systems can lead to significant differences in the amount of calcium available for analysis. At alkaline pH calcium can be adsorbed onto the metallic components of the sampling system, and under more acidic conditions calcium can be released. Thus an alkaline sample will have an apparently reduced calcium content, while a more acidic sample may have an apparently increased concentration of calcium. By using non-metallic components in the sampling system this source of error an be eliminated.     

A factor analysis of the social interest index-revised

Factor analyzed the Social Interest Index–Revised (SII-R), an instrument developed to measure the level of social interest that an individual has attained in each of four life task areas. Four factors (N = 308) were defined: A self-significance factor, a love factor, a freindship factor. The four factors combined accounted for 38.8% of the total variance. The results supported the empirical validity of the scale and provided further evidence for researchers who are seeking to define social interest in measurable terms.     

新生儿ABO溶血病相关母亲因素分析

目的观察分析孕妇血清IgG抗A（B）效价、妊娠次数及年龄因素与新生儿溶血病的相关性。方法检测母婴血型不合孕妇血清IgG抗A（B）效价,分别统计不同IgG抗A（B）效价的孕产妇中发生因ABO血型不合所致的新生儿溶血病的比率,并比较不同妊娠次数、不同年龄段的孕妇发生新生儿溶血的比率。结果孕妇不同血清IgG抗A（B）效价时、不同妊娠次数时及孕妇的不同年龄段时发生新生儿ABO溶血病的比率之间均有统计学差异（P〈0．05）,随着孕妇血清IgG抗A（B）效价的增高、妊娠次数的增加及孕妇年龄的增加,新生儿ABO溶血病的发病也增多。结论为保障母婴安全,减少新生儿溶血病的发生率,有条件时检测孕妇血清IgG抗A（B）效价,并尽量减少妊娠次数及避免高龄怀孕。     

The latent factor structure of the WAIS-R: a factor analysis of individual item responses

Factor analytic examination of a 166 x 166 intercorrelational matrix that represents individual item scores from the 11 subtests of the WAIS-R provided evidence of five interpretable factors (N = 409). Two of these were identified as the Verbal and Performance factors previously encountered in traditional WAIS-R subtest-based factor analyses. The other three factors were characterized readily as involving (1) Advanced Vocabulary skills; (2) Basic Responsivity and (3) Advanced Computational ability. All three of these "new" factors accounted for at least 10% of the total variance, and comments are made with regard to the possible significance of their discovery to such topics as subtest variation and profile psychodiagnostics, theories that pertain to the nature and structure of human intellectual functioning, and subtest-based personality measurement theories.     

A factor analysis of coping behaviors

Undertook factor analysis on questionnaire data that deal with ways of diminishing tension. Data were obtained on 132 college students. Seven patterns of coping were identified tentatively: seeking social support, dysfunctional behavior, narcotizing anxiety, problem solving, reliance on professionals, bearing with discomfort, and escape.     

Exploratory factor analysis of the WAIS-III in a mixed patient sample.

The Wechsler Adult Intelligence Scale-III (WAIS-III) was administered to 152 patients at a VA Medical Center. Means for age, education, and Full Scale IQ were 51.49 years (SD = 13.00), 12.43 years (SD = 2.00), and 92.61 (SD = 14.06), respectively. Of the 152 patients, 69 had substance abuse disorders, 39 had medical/neurological conditions, 27 had both substance abuse and psychiatric disorders, and 17 had psychiatric conditions. The 13 WAIS-III subtests were subjected to a principal-axis factor analysis with oblimin rotation. Four factors were specified to be retained. The Verbal Comprehension, Perceptual Organization, and Processing Speed factors were identical to those in the standardization sample. However, Arithmetic could not be allocated to any factor within the patient sample. The Working Memory factor consisted only of the Digit Span and Letter-Number Sequencing subtests. © 2000 National Academy of Neuropsychology. Published by Elsevier Science Ltd     

A factor analysis of the items of the imaginal processes inventory

Over the last several years, responses to the Imaginal Processes Inventory (IPI) developed by Singer and Antrobus have been collected on over 1300 men and women from age 17 to 92 years. The IPI contains items that concern various aspects of daydreaming and attentional processes. The 344 items of the Imaginal Processes Inventory plus age were intercorrelated for the 1300 S sample. This intercorrelation matrix was subjected to a principal components analysis; 53 principal components then were rotated to a Varimax solution. The Varimax solution was transformed, which led to item coefficients that permit the calculation of factor scores for each S on each of the factorially pure components of the Imaginal Processes Inventory. Results of the factor analysis are given in terms of the meaningfully interpreted components. Also presented are mean factor scores for men and women for 12 age groups.     

Confirmatory factor analysis of the Parental Bonding Instrument in a Japanese population

BACKGROUND: There is controversy surrounding the factor structure of the Parental Bonding Instrument (PBI), a widely used instrument for assessing perceived parental rearing behaviours. Recent studies have proposed five different factor structures, including Parker et al.'s original two-factor model. METHODS: Four hundred and eighteen employed Japanese adults filled out the PBI. Maximum likelihood confirmatory factor analyses were performed to compare the five different factor structures in terms of model-fit. RESULTS: Parker's original two-factor structure fitted the data poorly. In general, three-factor structures showed better fit. Among the three-factor structures, Murphy's model and Kendler's model were superior (the adjusted goodness-of-fit index > 0.8), with the latter providing the best fit to the data (the goodness-of-fit index > 0.9). When considering invariance of factor structure across gender subgroups and across age subgroups, only Kendler's model was acceptable. CONCLUSIONS: Parker's two-factor structure of the PBI may not be appropriate for assessing perceived parental rearing behaviours in a Japanese population. Three-factor structures, in particular Murphy's model and Kendler's model, are preferable. Kendler's model provided the best fit to the data and was relatively invariant across the subgroups in this study. Thus, Kendler's model might prove to be very important for obtaining a factor structure invariant across different cultures.     

An examination of the validity of EPSCALE using factor analysis

Objective

To examine the validity and utility of the Explanation and Planning Scale (EPSCALE) instrument, a widely used scale for teaching and assessment of explanation and planning skills used by clinicians during the medical interview.

Methods

Data obtained across 4 OSCE stations during medical student final MB examinations. Exploratory factor analysis, using a single factor and two factor models (based on prior theory) and a six factor empirical model, suggested by parallel analysis.

Participants

124 medical students sitting final MB examinations at the University of Cambridge.

Results

A single factor model represented a very poor fit. A two factor model with factors labelled ‘Explanation’ and ‘Planning’ produced an improved fit, but the best was seen with a six factor model, with factors which broadly corresponded to the domains of the Calgary–Cambridge guide.

Conclusions

These factor models provide supportive evidence for the construct validity of EPSCALE.

Practice implications

EPSCALE can justifiably be used in the assessment of shared-decision making skills.     

新生儿先天畸形134例相关因素分析报告

目的探讨导致新生儿畸形的各种可能相关因素.方法回顾性分析1995年～2000年7年间本院新生儿畸形、死亡的病例.结果统计分析新生儿畸形134例 ,占同年围产儿分娩人数0.65%,前三位的新生儿畸形为:唇腭裂(19.26%)、先天性心脏病(15.6%)、多指/并指畸形(9.63%).新生儿畸形中在第二季度出生者比其他季度高, 畸形儿男婴较女婴多.相关因素方面:AB血型孕妇较易分娩神经系统、心血管系统畸形儿. 职业是农民的孕妇分娩的新生儿神经系统畸形比率较大,母亲是职员的新生儿颜面畸形和唇腭裂所占的比率较大.丈夫饮酒和/或吸烟者,新生儿消化系统、心血管系统畸形比率高. 结论新生儿畸形与孕期病毒感染、母亲血型、职业以及父亲饮酒、吸烟有关.应加强孕前及孕期保健,积极开展产前诊断工作,降低新生儿畸形率.还应对可能的影响新生儿畸形的各因素进行进一步研究,明确各发病因素的相关性.     

听觉诱发电位提取方法的研究与分析

论述了运用小波变换进行听觉诱发电佗单次提取的原理、方法和实验分析。结果表明，对单次试验信号，经小波变换及相关分析后，可从带自发脑电干扰的信号中提取诱发电位信号。小波变换分析方法与传统的叠加平均方法相比，可减少试验次数，缩短检测周期。     

On the existence of an unambiguous solution in factor analysis of dynamic studies

Achievement of an unambiguous solution in factor analysis of dynamic radionuclide studies depends on constraints reflecting the known properties of factors. The constraints should be tight enough to prevent ambiguity but sufficiently general in order to ensure the data-based derivation of factors. In dynamic scintigraphy, the non-negativity of factors is their essential property which is implied by the physical nature of measured quantities. Considering factors as the images of compartments in the distribution space of a radiopharmaceutical (i.e. performing the factor analysis in the spatial domain), a powerful additional constraint can be applied. This constraint is based on the presence of segments in the image matrix where the subtotal number of compartments is projected. Using this constraint, the existence of physiologically related unique solution in factor analysis can be proved providing the number of factors is chosen properly.     

Multiple-group factor analysis of the Wechsler Intelligence Scale for Children

Confirmatory factor analyses were performed on the intercorrelations among the 12 tests of the WISC and WISC-R separately for age levels 7.5, 10.5, and 13.5 to test Wechsler's (1958) hypothesis that verbal and performance factors underlie these tests. At all three age levels, verbal and performance factors that accounted for approximately 50% of the total variance emerged clearly. These results provide strong empirical support for Wechsler's hypothesis.     

Reliability and factor analysis of the Epworth Sleepiness Scale.

The Epworth Sleepiness Scale (ESS) is a self-administered eight-item questionnaire that has been proposed as a simple method for measuring daytime sleepiness in adults. This investigation was concerned with the reliability and internal consistency of the ESS. When 87 healthy medical students were tested and retested 5 months later, their paired ESS scores did not change significantly and were highly correlated (r = 0.82). By contrast, ESS scores that were initially high in 54 patients suffering from obstructive sleep apnea syndrome returned to more normal levels, as expected, after 3-9 months' treatment with nasal continuous positive airway pressure. The questionnaire had a high level of internal consistency as measured by Cronbach's alpha (0.88). Factor analysis of item scores showed that the ESS had only one factor for 104 medical students and for 150 patients with various sleep disorders. The ESS is a simple and reliable method for measuring persistent daytime sleepiness in adults.