Assessment of quantitative artificial neural network analysis in a metabolically dynamic ex vivo 31P NMR pig liver study

Quantitative artificial neural network analysis for 1550 ex vivo 31P nuclear magnetic resonance spectra from hypothermically reperfused pig livers was assessed. These spectra show wide ranges of metabolite concentrations and have been analyzed using metabolite prior knowledge based lineshape fitting analysis which had proved robust in its biochemical interpretation. This finding provided a good opportunity to assess the performance of artificial neural network analysis in a biochemically complex situation. The results showed high correlations (0.865 < or = R < or = 0.992) between the lineshape fitting and artificial neural network analysis for the metabolite values, and the artificial neural network analysis was able to fully represent the trends in the metabolic fluctuations during the experiments.     

Allowing for correlations between correlations in random-effects meta-analysis of correlation matrices.

Practical meta-analysis of correlation matrices generally ignores covariances (and hence correlations) between correlation estimates. The authors consider various methods for allowing for covariances, including generalized least squares, maximum marginal likelihood, and Bayesian approaches, illustrated using a 6-dimensional response in a series of psychological studies concerning prediction of exercise behavior change. Quantities of interest include the overall population mean correlation matrix, the contrast between the mean correlations, the predicted correlation matrix in a new study, and the conflict between the existing studies and a new correlation matrix. The authors conclude that accounting for correlations between correlations is unnecessary when interested in individual correlations but potentially important if concerned with a composite measure involving 2 or more correlations. A simulation study indicates the asymptotic normal assumption appears reasonable. Because of potential instability in the generalized least squares methods, they recommend a model-based approach, either the maximum marginal likelihood approach or a full Bayesian analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Voice predicts affect during psychotherapy

This study examined the relationship between emotions and the frequency and power characteristics of the voice in psychotherapy. The intensity of fear, anger, depression, and total affect in each of four interviews with one patient was rated every 20 seconds on a nine-point scale. Significant agreement among judges was achieved. Voice samples from each epoch in which there was sufficient speech were subjected to spectral analysis of the frequencies between 0 and 1000 HZ. These spectra were scored for nine frequency and power parameters. Multiple linear regression equations were then developed from two interviews, using the nine voice spectral variables as predictors and the mean ratings for each affect as the criterion variables. Significant multiple correlations were achieved between every rated affect and various combinations of voice variables. The beta weights and constants from these equations were then employed in the successful prediction of levels of anger, fear, depression, and total affect in one interview, and the levels of depression and total affect in another interview. In addition, epochs of conflict differed from "pure" affect epochs, and pure epochs of anger, fear, and depression differed from each other in various frequency and power characteristics of the voice. Voice spectral measures may be an objective means of identifying and quantifying affect in psychotherapy.     

CPT-DMT Correlations

Although the cone penetration test (CPT) and flat-plat dilatometer test (DMT) have been used for over 30 years, relatively little has been published regarding comprehensive correlations between the two in situ tests. This paper presents preliminary correlations between the main parameters of the CPT and DMT. The key to the proposed correlations is the recognition that the main DMT parameters are normalized and hence, should be correlated with normalized CPT parameters. The suggested correlations are developed and evaluated using published records and existing links to various other parameters as well as comparison profiles. The suggested correlations may guide future more detailed correlations between these two in situ tests.     

On the psychometric principles of affect.

D. Watson and L. A. Clark (see record 1997-03581-003) announced "two fundamental psychometric principles" (p. 282) of affect: The positive correlation between affects with the same valence tends to be substantial, whereas the negative correlation between affects with opposite valence tends to be weak. These allegedly robust empirical generalizations underlie various conceptual models of affect (such as those that posit an independence between positive and negative affect) and various scales of affect. The authors offer an alternative analysis: The correlation between two affects is a function of the angle between them within a circular ordering. Two data sets were reanalyzed and showed predicted exceptions to Watson and Clark's principles: same-valenced pairs with weak correlations and oppositely valenced pairs with substantial correlations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A new attenuated total reflectance Fourier transform infrared spectroscopy method for the study of proteins in solution

An attenuated total reflectance Fourier transform infrared method has been developed that allows collection of spectra from proteins in solution. This method eliminates any structural perturbations induced by the internal reflection element (IRE), and thus the spectra reflect the solution conformation of the protein. A key feature of the method is subtraction of the signal from any protein adsorbed to the IRE. The advantages of this method include the small amount of sample required and the high sampling rate. Attenuated total reflectance (ATR)-Fourier transform infrared spectroscopy (FTIR) is more versatile than transmission FTIR because it is possible to collect spectra of nontransparent samples, to use samples of very low protein concentration (< or = 0.3 mg/ml), and to study proteins in the presence of strongly absorbing solutes (such as denaturants). The experimental procedures and data processing routines developed were evaluated by collecting spectra from a set of 13 proteins and evaluating their accuracy with a partial least-squares analysis. The relative mean and standard deviation errors for the basis set analysis were 6.3% for alpha-helix, 5.9% for beta-sheet/extended structure, and 4.4% for turn, which are similar to values from comparable analyses of transmission FTIR spectra. In addition, a detailed comparison between this solution ATR method and the hydrated thin-film ATR technique is presented.     

The origins of the correlations between tobacco, alcohol, and cannabis use during adolescence

Methods of structural equation modelling were used to analyse the correlations between reports of tobacco, alcohol, and cannabis use in a birth cohort of New Zealand children studied to the age of 16. This analysis produced three major conclusions: (a) the correlations between tobacco, alcohol, and cannabis use could be explained by a factor representing the individual's vulnerability to substance use; (b) predictors of vulnerability to substance use were the extent to which the individual affiliated with delinquent or substance using peers, novelty seeking, and parental illicit drug use; (c) in the region of 54% of the correlations between substance use behaviours could be predicted from observed risk factors and 46% was attributable to non-observed sources of vulnerability.     

Dietrich Object Relations and Object Representations Scale: Convergent and discriminant validity and factor structure.

Introduces the Dietrich Object Relations and Object Representations Scale (DOROS; D. R. Dietrich, 1985), and assesses convergent and discriminant validity and factor structure. Among other dimensions, the DOROS measures object investment, object love, object warmth, empathy, depression, and psychological mindedness. The scale was applied to Thematic Apperception Test data. 102 psychiatric Ss and 48 nonpsychiatric volunteers were included in the study. Factor analysis revealed 1 structural factor and 1 content factor. Convergent validity was supported through correlations between the factors and the Conceptual Level of Object Representations Scale as described by S. J. Blatt et al (1988). The content factor correlated with Mutuality of Autonomy Scale as described by J. Urist and M. Shill (1982), whereas the structural factor did not. Discriminant validity was supported via correlations with 2 measures of verbal ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of NGF and sensory nerve stimulation on collateral sprouting and gene expression in adult sensory neurons

Cerebroside sulfate activator protein (CSAct or saposin B) is one of a group of heat stable, low-molecular-weight proteins that appear to share a common structural motif. These have been referred to as saposin-like proteins and are thought to share a multiple amphipathic helical barrel structure with a conserved pattern of disulfide linkages. Porcine kidney CSAct was prepared in high purity and consisted of three major glycosylated subforms. The protein was studied by physical-chemical methods and evaluated by various methods for structural prediction. All suggest that CSAct has high amounts of alpha-helical conformation and little if any beta-sheet. Circular dichroism (CD) studies indicate 45-50% helical conformation depending on buffer and temperature. There was only a moderate loss in helical content with increasing temperature and no indication of thermal denaturation. Fourier transform infrared spectroscopy (FTIR) measurements on deuterium hydrated self-films also indicated a predominantly helical structure. Helical axis orientation was investigated by both oriented CD and FTIR dichroism, which suggested that the helical axes were roughly parallel and oriented along the axis of the surface on which the self-films had been deposited. One-dimensional nuclear magnetic resonance spectra showed large chemical shift dispersion, indicating a defined tertiary structure with little variation between 6 and 85 degrees C. NOESY spectra failed to show the strong NOE cross peaks expected for a highly helical conformation. This may indicate short-term conformational flexibility within the helices or molecular aggregation at the high protein concentrations employed. These observations are consistent with the 3-4-helix bundle motif suggested for saposin-like proteins by various predictive algorithms.     

Structural parallels between pretend play and narratives.

Pretend play productions of 46 children from 4 through 8 years of age were analyzed using a story grammar. Results showed structural parallels between pretend play and stories for 76% of Ss. Older Ss' play was Episodic (story-like); younger Ss' play was Preepisodic. Given structural parallels, a play complexity measure was established on the basis of the semantic link between Episodes. Preepisodic play was also differentiated. There were strong correlations between age and play level, and age and play length in Episodes. But number of propositions per episode remained constant at approximately 6. Ss' verbalizations explicated two aspects of pretend, setting-up and play, and some Ss indicated a preference. The authors conclude with a discussion about the relationship between play's form and function. Story grammar analysis proved a valid tool for studying play's structure within a developmental framework. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural equation modeling with longitudinal data: Strategies for examining group differences and reciprocal relationships.

This article describes the use of structural equation modeling with latent variables to examine group differences and test competing models about cause–effect relationships in passive longitudinal designs. This approach is compared with several other statistical methods including analysis of cross-lagged panel correlations, regression analysis, and path analysis. The mechanics and advantages of structural equation modeling are illustrated using an example based on a 3-wave longitudinal study of adolescents' alcohol use. Within this example, the generalizability of the measurement model and structural model are assessed across gender and time, and competing models about the causes and consequences of adolescents' alcohol use are tested. The article concludes with a discussion of some of the strengths and limitations of using structural equation modeling with longitudinal data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phantom glucose calibration models from simulated noninvasive human near-infrared spectra

The validity of published reports claiming to have successfully measured in vivo blood glucose from noninvasive near-infrared spectra collected in a time-dependent manner is challenged on the basis of results obtained from a phantom glucose spectral data set. An in vitro model is used to simulate noninvasive human near-IR spectra. The phantom glucose data set is created by purposely omitting glucose in these modeled samples. Glucose values are then assigned to successive phantom glucose spectra, and multivariate calibration models are generated for glucose based on partial-least squares regression. As expected, calibration models are incapable of predicting glucose values when the glucose assignments are made randomly. Apparently functional models are obtained, however, when glucose assignments are made in a nonrandom, time-dependent manner. Prediction errors from these nonrandom models are essentially identical to those published by other as evidence of successful noninvasive blood glucose measurements. Chance temporal correlations between assigned glucose concentrations and some uncontrolled experimental parameter are responsible for this apparent model functionality.     

Subject-centered scalability: The sine qua non of summated ratings.

A unifying theory of subject-centered scalability is offered that is grounded in structural true score modeling, is conceptually distinct from internal consistency and homogeneity as determined by item correlations, and is empirically confirmable. Scalability holds when item true scores are perfectly correlated but differ in their individual scale metric. The condition of scalability imposes constraints that allow individual item reliability to be estimated independently of scalability. Scalability is shown to imply unit rank and to be testable by a single-factor confirmatory factor analysis reinterpreted as a test of unit rank. High item correlations are shown, contrary to intuition, to be an insufficient condition for scalability. Conversely, low item correlations do not necessarily imply lack of scalability. A stepped decision-oriented procedure is offered as a guideline in summated rating scale construction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of member influence in an organization: Phenomenology versus organization structure.

This study explores the relative tenability of 2 hypotheses concerning the effects on members' loyalty and activity of membership influence in an organization. The phenomenological hypothesis explains the effects in terms of the influence which the members perceive to exist; the structural hypothesis in terms of the influence that actually does exist. This is a secondary analysis of questionnaire data from a previous survey of 104 leagues of the League of Women Voters of the U. S. Significant interleague correlations are found between members' average perceptions of membership influence in their respective leagues and the average loyalty and activity of members in these leagues who are matched on perception of influence. These correlations cannot easily be explained phenomenologically since the members who differ in loyalty and activity report identical perceptions of membership influence. (34 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

非均匀a Si:H层的光致发光光谱研究

本文报道了沉积于玻璃基板上的a Si:H 基结构在6 K下测定的光致发光光谱。认为其非高斯特性是由材料中的不同相引起的。由光谱拟合获得的数值数据结果显示,它们可以认为是两种有不同结构无序化度区域的光致发光叠加的结果。这是沉积过程的问题,相当于无定形氢化硅结构性能的理想情况。     

Repair of skin defects by skin extension procedures

The modern structural methods used in the determination of lipopolysaccharides chemical structures were described. The combination of nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MALDI-TOF, FAB and EI) applied to structural analysis of lipopolysaccharides, with a few chosen examples of characteristic original spectra were presented.     

Computer-Aided Model Generation for Nonlinear Structural Analysis Using a Structural Component Model Database

This paper presents an approach for efficiently building analytical models for nonlinear analysis. The objective has been achieved by establishing structural component model database by collecting various structural component models addressing various structural details. A common data structure and a relational database schema for storing structural component models were proposed in this study. The proposed structural component model database can serve as a decision supporting system for building nonlinear analytical models manually. In addition, the modeling information stored in this database can be presented in XML document format to be parsed and manipulated by computer system for generating nonlinear analytical model in file automatically. A school building database is used as a case study to show the feasibility of automatic modeling for nonlinear analysis using the proposed structural component database. A semiautomatic model generation system was developed to provide an efficient modeling process, which is in the manner of form filling and option selecting on web-based user interfaces, so that the model builder can focus on making engineering decisions. The modeling details are handled automatically by the proposed system based on user selection and setting.     

A meta-analytical structural equations analysis of a model of employee turnover.

Combined meta-analysis with structural equations modeling (SEM) to validate the W. H. Mobley et al (1978) turnover theory as well as alternative structural networks proposed by A. Dalessio et al (1986), P. W. Hom et al (1984), and B. D. Bannister and R. W. Griffeth (1986). The authors aggregated correlations from 17 studies (N?=?5,013 employees), correcting for unreliability and sampling error. Then they used SEM to assess the models, comparing their relative fits to data. SEM analyses corroborated the Mobley et al model better than did past research, but these analyses also showed that the Dalessio et al and the Hom et al theories explained sample data more plausibly. Additional SEM tests found that turnover base rates, time lags between turnover and model assessments, unemployment rates, and occupational differences moderated the models' pathways. The present findings suggest various implications for these theories and for turnover research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facility-level outcome performance measures for nursing homes

Risk-adjusted nursing home performance scores were developed for four health outcomes and five quality indicators from resident-level longitudinal case-mix reimbursement data for Medicaid residents of more than 500 nursing homes in Massachusetts. Facility performance was measured by comparing actual resident outcomes with expected outcomes derived from quarterly predictions of resident-level econometric models over a 3-year period (1991-1994). Performance measures were tightly distributed among facilities in the state. The intercorrelations among the nine outcome performance measures were relatively low and not uniformly positive. Performance measures were not highly associated with various structural facility attributes. For most outcomes, longitudinal analyses revealed only modest correlations between a facility's performance score from one time period to the next. Relatively few facilities exhibited consistent superior or inferior performance over time. The findings have implications toward the practical use of facility outcome performance measures for quality assurance and reimbursement purposes in the near future.     

Effect of Nd3+ substitution on structural and magnetic properties of Mg–Cd ferrites synthesized by microwave sintering technique

Nd~(3+) substituted spinel ferrites with formula Mg_xCd_(1-x)Nd_(0.03)Fe_(1.97)O_4(x = 0.0.2,0.4,0.6.0.8 and 1.0)were prepared by oxalate co-precipitation method using novel microwave sintering technique. AR grade sulphates were used as starting chemicals. The samples were sintered at optimized power of 70 W for10 min in a microwave oven(800 W). The structural analysis of these samples was done by using X-ray diffraction, scanning electron microscope and Fourier transform IR techniques. The XRD analysis of the synthesized ferrite confirms the formation of cubic spinel structure of ferrite. The influence of Nd3+substitution on various structural parameters of Mg-Cd ferrites was reported. IR study indicates the spectra contain two intense absorption bands around 600 and 400 cm~(-1) in addition with four extra bands. The magnetic properties of all ferrites were studied by using a vibration sample magnetometer.The crystallite and grain size dependant magnetic properties are observed. The composition Mg_(0.6)Cd_(0.4)Nd_(0.03)Fe_(1.97)O_4 has better magnetic properties that can be used in recording media. The fast synthesis of spinel ferrites is yielded due to use of the microwave sintering technique.