Citrate substitutes for homocitrate in nitrogenase of a nifV mutant of Klebsiella pneumoniae

An organic acid extracted from purified dinitrogenase isolated from a nifV mutant of Klebsiella pneumoniae has been identified as citric acid. H2 evolution by the citrate-containing dinitrogenase is partially inhibited by CO, and by some substrates for nitrogenase. The response of maximum velocities to changes in pH for both the wild-type and the NifV- dinitrogenase was compared. No substantial differences between the enzymes were observed, but there are minor differences. Both enzymes are stable in the pH range 4.8-10, but the enzyme activities dropped dramatically below pH 6.2.

Personality, social support, and psychological distress in later life

A conceptual model was developed to address 2 issues that have received relatively little attention in the social support literature. First, an attempt was made to assess the interrelationships among 3 types or dimensions of supportive social relations. In addition, the impact of selected psychological and social factors on social support use was examined. Findings from a nationwide survey of older adults in the United Kingdom suggest that social contact tends to increase the amount of received support, and received support in turn tends to bolster perceptions of support availability in the future (i.e., anticipated support). With regard to the second issue, social roles (especially marital status) and social extraversion emerged as potentially important correlates of social support use in later life.

[Study on the production, identification of serogroup-specific monoclonal antibodies against leptospires of Australis serogroup and detection of its antigen]

Spleen cells of BALB/c mice immunized with whole Leptospira interrogans serogroup Australis serovar australis strain 620 were fused with myeloma cells line SP2/0. Specificities of four McAbs determined by MAT. 2E1 McAb (IgG3) reacted with 11 serovars, of the Australis serogroup, but did not react with 22 representative serovars of L. interrogans in 20 serogroups, L. biflexa strain patoc I and Leptonema illini strain 3055. 2E1 McAb showed serogroup specificity for Australis by agglutination and the other 3 McAbs showed partial serogroup specificity. We compared the outer envelope (OE) protein profiles of serovar australis strain 620 with those of two pathogenic L. interrogans serovar lai strain 601 and serovar hebdomadis strain 156 by SDS-PAGE. 63kd protein profile was only found in the OE of strain 620, and the quantity of 42kd protein of strain 620 was greater than that of strain 601 and 156. The immunoblotting revealed that 2E1 McAb reacted with a 34kd band in the OE preparation of serovar australis strain 620, but did not react with that of other two L. interrogans. 2E1 McAb also did not react with OE of non-pathogenic leptospires. It was suggested that 34kd protein might contain the antigenic determinants which were shared by leptospires of Australis serogroup.

Analytical approaches to detection and characterization of disease-linked chromosome aberrations

Flow karyotyping and FISH with chromosome specific or disease-locus-specific probes are powerful adjuncts to conventional cytogenetic analysis. Flow karyotyping is well suited to quantitative analysis of DNA content changes that occur during structural rearrangement. FISH with probes for repeated sequences allows ready detection of aneuploidy in interphase cells. FISH with whole chromosome composite probes to metaphase spreads facilitates detection of subtle structural changes and allows detection of structural aberrations that occur at frequencies as low as 10(-3). FISH with locus-specific probes facilitates diagnosis of specific genetic diseases, allows phenotype-genotype correlation on a cell-by-cell basis and may be developed into a sensitive method for detection of residual disease.

Clinical application of microcomputer to visual function examination

Microcomputer technique is put into use in ophthalmological clinical visual function examination. In visual EOG, ENG, visual tracking, contrast sensitivity and VEP examination, objectifying and standardization of experiment and data analysis are achieved by computer technique. In addition, a lot of manpower and time is saved, test results are obtained faster and more accurately. The basic rational of computerization in clinical visual function examination is presented.

[Preliminary report of efficacy of diabetic polyneuropathy treated with large dose inositol]

Ten diabetics with polyneuropathy were studied by taking 6g inositol tablets (each tablet contains 0.25g inositol) per day for three months. The results showed that large dose inositol could reduce the severity of clinical symptoms, but there was no improvement of the nerve conduction velocity. The possible mechanism of these changes was discussed. According to the clinical observation of the therapeutic effect in those 10 cases, the authors would deem that large dose inositol is an effective drug for diabetic polyneuropathy, and it is worthy of further clinical trial, but other sensitive indicators should be used to evaluate the efficacy of this drug.

Appropriateness of composites in structural equation models

The appropriateness of using composites instead of multiple indicators in a structural model of physical health was evaluated. Liang's (1986) specification of self-reported physical health is a relatively complex multiple indicators model which may not be practical in actual application. To simplify this formulation, a two-stage strategy was used. First, reliability was estimated for each composite to fix the measurement error variance and the regression of the composite on the latent variable. Second, the model was reestimated by constraining these parameters. Regression analyses were undertaken to assess the impact of using composites instead of multiple indicators. Parameter estimates for causal linkages and residual error variances based on multiple indicators approach were closely reproduced by using composites, thus providing justification for the proposed strategy.

Peer influence in adolescent cigarette smoking

A structural model relating actual and perceived peer smoking to perceived peer pressure and to adolescent cigarette smoking was developed and replicated in two independent subsamples of the data. Data was gathered from 2334 suburban adolescents in grades 8 and 11 in a large metropolitan area. Four dimensions of peer pressure were discovered and were found to relate differentially to adolescent smoking. The major findings were that pathways representing modeling and normative pressure to smoke had roughly equal impact on adolescent smoking. Direct pressure to smoke cigarettes did not have a significant path to adolescent smoking. Adolescents reported low levels of both normative and direct pressure to smoke cigarettes. Smoking adolescents appear to see the peer group, not as encouraging them to smoke, but as not providing any discouragement for smoking. Finally, adolescents who were experimenting with smoking or were smokers overestimated the amount of smoking by their best friends.

Personality, social support, and psychological distress in later life

A conceptual model was developed to address 2 issues that have received relatively little attention in the social support literature. First, an attempt was made to assess the interrelationships among 3 types or dimensions of supportive social relations. In addition, the impact of selected psychological and social factors on social support use was examined. Findings from a nationwide survey of older adults in the United Kingdom suggest that social contact tends to increase the amount of received support, and received support in turn tends to bolster perceptions of support availability in the future (i.e., anticipated support). With regard to the second issue, social roles (especially marital status) and social extraversion emerged as potentially important correlates of social support use in later life.

Binding of sulfonamide and acetamide to the active-site Zn2+ in carbonic anhydrase: a theoretical study

Self-consistent field molecular orbital (SCF MO) calculations at both 4-31G and STO-3G levels have been used to examine the binding conformations of sulfonamide and acetamide compounds to the active site of carbonic anhydrase. The results are as follows: (1) sulfonamide binds to the Zn2+ ion in its deprotonated form through the sulfonamide nitrogen to the fourth coordination site of the metal ion; (2) acetamide as neutral species binds to the basic form of the enzyme through the carbonyl oxygen to the fifth coordination site of the metal ion; and (3) the acetamidate ion binds to the acid form of the enzyme through the amide nitrogen to form a tetracoordinated metal complex with three histidine ligands. Analysis of the effects of individual active-site residues on the binding conformations of these inhibitors suggests that metal alone favors bidentate coordination of sulfonamidate and acetamidate complexes and that electron donation from three histidine ligands to the metal ion determines the formation of a tetracoordinated metal complex, which is further stabilized by the presence of Thr 199, as it receives one hydrogen bond from the sulfonamide NH- or from the acetamide NH- and donates a backbone NH hydrogen bond to a sulfonamide oxygen. The calculated binding conformation of sulfonamide and the hydrogen-bonding interactions between sulfonamide and the enzyme are consistent with the X-ray diffraction study of the AMSulf-HCA II complex. However, no X-ray structures are available for amide-HCA II complexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Near-ultraviolet circular dichroism of bovine high molecular weight alpha-crystallin

High molecular weight (HMW) alpha-crystallin isolated from cow nucleus has a molecular weight greater than 5 x 10(6) Daltons. Its particle dimensions have been reported to be over 500 nm. It is derived mainly from low molecular weight (LMW) alpha-crystallin. The conformational change as LMW alpha-crystallin is converted into HMW alpha-crystallin was studied by near-ultraviolet circular dichroism (NUV-CD). The main concern in measuring CD for protein aggregates with particle dimensions as high as HMW alpha-crystallin and with an irregular shape is the contribution of differential scattering. The differential scattering becomes increasingly more important for particles with dimensions greater than 1/20th the wavelength of light. This contribution was minimized by increasing the acceptance half-angle of detection. The present data indicate that bovine HMW alpha-crystallin has a different tertiary structure from LMW alpha-crystallin.

Dimensions of the OARS mental health measures

A measurement model of mental health for the Older Americans Resources and Services (OARS) questionnaire is described. Using confirmatory factor analysis on noninstitutionalized elderly from Cleveland (N = 1834) and Virginia (N = 2146), the 21 OARS mental health items were fit to a 15-item model. In addition to the second-order construct of mental health, there were four first-order dimensions: life satisfaction, psychosomatic symptomatology, alienation, and cognitive deficit. Analyses were further replicated by splitting both samples in half. The model fit well and compared favorably to other alternative specifications. In addition to this analysis of internal structure, the model was also examined in relation to several exogenous factors including age, sex, race, education, and physical health. While the model again fit well, a model with cognitive deficit separate from the other factors seemed more reasonable.

Mortality decline and Chinese family structure: implications for old age support

This study examined the effect of mortality change on the probabilities of survival for various family members and parent/child joint life expectation in Chinese mainland and Taiwan during the past 60 years. Major increases in life expectancy have led to the doubling of the average number of person years of an individual's life spent as a grandparent during that time. In a sense, the family burden of old age support is twice as much as before. It is concluded that the role of family in providing old age support needs to be complemented and reinforced by public programs.

N2O reduction and HD formation by nitrogenase from a nifV mutant of Klebsiella pneumoniae

Dinitrogenase from a nifV mutant of Klebsiella pneumoniae contains an altered form of iron-molybdenum cofactor (FeMoco) that lacks a biologically active homocitric acid molecule. Change in the composition of FeMoco led to substantial variation in the kinetics of nitrogenase action. The KmS of the mutant enzyme for N2 and N2O were 0.244 and 0.175 atm (24,714 and 17,726 kPa), respectively. The km for N2 was higher and the Km for N2O was lower than that for the wild-type enzyme. The mutant enzyme was ineffective in N2 fixation, in N2O reduction, and in HD formation, as indicated by the low Vmax of these reactions with saturating levels of substrate and under conditions of saturating electron flux. These observations provide further support for the concept that N2, N2O, and D2 interact with the same form of dinitrogenase. H2 evolution by the mutant enzyme is only partially inhibited by CO. Observation that different numbers of electrons are stored in CO-inhibited than in noninhibited dinitrogenase before H2 is released suggests that the mutant enzyme has more sites responsible for H2 evolution than the wild-type enzyme, whose H2 evolution is not inhibited by CO.

The acceptance and completion of mammography by older black women

We assessed the relation of patient characteristics, knowledge and beliefs to the utilization of mammography in an inner-city setting by 187 Black women over the age of 50. Thirty per cent of those who were offered mammography initially declined the offer and 40 per cent were subsequently unable to complete the procedure. Patient interviews were used to derive 27 potential knowledge and health belief predictor scales. In multiple regression analysis, two health belief scales and two knowledge scales accounted for 15 per cent of the observed variance in the model of acceptance. The strongest predictor of subsequent completion was initial acceptance. The presence of breast symptoms and two health belief scales together with initial acceptance accounted for 26 per cent of variance in the model of completion. These results suggest that the successful accomplishment of mammography requires coordinated efforts at the level of the provider, patient, and setting. Health beliefs may influence the patient's behavior in this process, but their effect appears to be modest.

Generational differences in the structure of the CES-D scale in Mexican Americans

This study examines differences in the structure of the Center for Epidemiologic Studies Depression (CES-D) scale across three generations of Mexican Americans. The covariance structure of the items was viewed as a function of several parameter matrices. Factorial invariance was evaluated by testing a series of hypotheses involving equivalence constraints on one or more parameter matrices. The findings revealed that the proposed 12-item model fits the data within each of the three generations adequately. Although no generational differences in factor loadings were revealed, structural variations of the CES-D in measurement error variances were found. Measurement error variances associated with certain items in the older generation are significantly greater than those in the middle-aged and young generations. In addition, socioeconomic characteristics, acculturation, and health status fail to explain the observed differences in the structure of the CES-D among the three generations.

Satisfaction with social support and depressive symptoms: a panel analysis

The literature suggests that persons who are dissatisfied with the amount of social support that has been provided to them may subsequently suffer from psychological disorder. At the same time, there is evidence that individuals who initially suffer from emotional disorder may consequently be less satisfied with their social support systems than may persons who enjoy better mental health. The purpose of this study was to test these competing hypotheses with panel data from a community survey of older adults. The findings indicate that changes in satisfaction with support tend to precede changes in depressive symptoms. A number of issues in the analysis of longitudinal data are discussed.

Satisfaction with social support and depressive symptoms: A panel analysis

The literature suggests that persons who are dissatisfied with the amount of social support that has been provided to them may subsequently suffer from psychological disorder. At the same time, there is evidence that individuals who initially suffer from emotional disorder may consequently be less satisfied with their social support systems than may persons who enjoy better mental health. The purpose of this study was to test these competing hypotheses with panel data from a community survey of older adults. The findings indicate that changes in satisfaction with support tend to precede changes in depressive symptoms. A number of issues in the analysis of longitudinal data are discussed.

Genotoxicity of [1H]benz[de]isoquinoline-1,3[2H]dione,5 amino-2-,[2-dimethylamino) ethyl] (BIDA) in human lymphocytes

We have investigated the genotoxicity of BIDA in cultured human lymphocytes. Lymphocytes were cultured and stimulated with phytohemagglutinin (PHA) for 72 h. Doses of 0.1, 0.25, 0.5, 0.75, and 1 microgram/ml of BIDA were added to the culture at 1 h (G2 phase), and 6 h (S/G2 phase) before harvesting. Cells were harvested at the end of the 72-h culture period with 1-h colcemid treatment to accumulate mitosis, and further prepared by standard cytogenetic technique. BIDA induced chromatic type breakages and chromatid exchanges at both 1 h and 6 h. The mean number of breakages per cell was 0, 0.1, 1.0, and 1.7 after treatment with 0.1, 0.25, and 0.75 micrograms/ml, respectively. Ai 1 microgram/ml, BIDA severely inhibited cell progression and very few mitoses were observed. At 6 h the mean number of breakages per cell was 0.3 at 0.25 microgram/ml and 1.2 at 0.5 microgram/ml. Very few cells entered mitosis at 0.75 and 1 microgram/ml. To study the effect of BIDA on cells in G0 and G1, BIDA (0.75 microgram/ml) was added for 1 h to the cultures at the beginning of culture (G0), or 24 h after (G1) culture initiation. Afterward, cells were washed and reincubated in the conditioned medium for 71 or 47 h. No chromosomal aberrations were seen in these experiments. The number of chromatid breaks was minimal (0.1 to 0.4/cell). Our study suggests that BIDA induces chromatid type aberrations during G2 and S phases. The absence of chromosome type aberrations in cells treated during G0 and G1 suggests that either BIDA has no effect on these cells or that damaged cells fail to progress through S and G2 to reach mitosis.

Structural integration of the Affect Balance Scale and the Life Satisfaction Index A: race, sex, and age differences

In this research we examined race, sex, and age differences in the factorial structure of Liang's (1985) model of subjective well-being that integrates the Affect Balance Scale and the Life Satisfaction Index A. In particular, we viewed the covariance structure of the items as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices with regard to the following: White and Black subsamples, men and women, and the young-old and the old-old. Data for the research came from the 1974 Harris National Council on Aging Survey, Myths and Reality of Aging in America. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance. Replicated race differences were found in the factorial structure, but sex and age differences were not found. Consistent race differences were found for the second-order factor loadings for negative affect.

Hydrogen burst associated with nitrogenase-catalyzed reactions

We have used a membrane-leak mass spectrometer to follow the time courses of H2 evolution and substrate reduction by nitrogenase [reduced ferredoxin:dinitrogen oxidoreductase (ATP-hydrolyzing), EC 1.18.6.1]. In the absence of added substrates, dinitrogenase passes all of its electrons to protons to form H2, but when a reducible substrate is added the electrons from dinitrogenase are shared between protons and the added substrate so that the steady-state rate of H2 production is decreased. If a reducible substrate is added before the nitrogenase reaction is initiated, a pre-steady-state burst of H2 is evident upon initiation of the reaction. This burst is associated with all the substrates of nitrogenase examined--i.e., N2, N2O, C2H2, NaN3, and NaCN. The H2 burst is stoichiometric with dinitrogenase, but not with dinitrogenase reductase. In the H2 burst phase, 1 H2 is evolved per dinitrogenase molybdenum. Although a change in the ratio of nitrogenase components changed the initial rate of the H2 burst, the stoichiometry was not affected. Production of H2 by the burst in the presence of a high concentration of substrate is terminated after production of 1 H2 per dinitrogenase molybdenum, and a steady-state rate of H2 production is established. This response suggests that the H2 burst is not a catalytic event but a result of a once-only activation process.

Structural integration of the Affect Balance Scale and the Life Satisfaction Index A: Race, sex, and age differences

In this research we examined race, sex, and age differences in the factorial structure of Liang's (1985) model of subjective well-being that integrates the Affect Balance Scale and the Life Satisfaction Index A. In particular, we viewed the covariance structure of the items as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices with regard to the following: White and Black subsamples, men and women, and the young-old and the old-old. Data for the research came from the 1974 Harris National Council on Aging Survey, Myths and Reality of Aging in America. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance. Replicated race differences were found in the factorial structure, but sex and age differences were not found. Consistent race differences were found for the second-order factor loadings for negative affect.

Differences in the structure of Life Satisfaction Index in three generations of Mexican Americans

This study examines differences in the structure of seven Life Satisfaction Index (LSI) items across three generations of Mexican Americans. Viewing the covariance structure of the items as a function of several parameter matrices, we analyzed factorial invariance by testing hypotheses involving equivalence constraints on one or more parameter matrices. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance. Differences in the factorial structure of the LSI were found between the older generation and the other two generations (i.e., the middle-age and younger generations). These differences persisted even when generational differences in education, income, and acculturation were taken into account. Further analyses revealed that generational differences were contained in only one (i.e., congruence) of the three first- comparisons in the other two dimensions (i.e., zest and mood tone) are appropriate.

The early detection of cancer in the primary-care setting: factors associated with the acceptance and completion of recommended procedures

Effective cancer control efforts in the primary-care setting require that patients accept and are able to complete recommended early detection procedures. We thus assessed the extent to which procedure nonacceptance or noncompletion limited accomplishment of detection procedures offered as components of routine health care. We also examined the relationship of provider and patient factors to successful procedure accomplishment. Of 221 patients offered procedures by their primary-care provider, 58 (27%) initially declined at least one recommendation, with acceptance rates ranging from 98% for breast exam to 59% for sigmoidoscopy. Furthermore, only 50% of patients offered stool occult blood testing or sigmoidoscopy, 61% offered mammography, and 69% offered Pap smear were able to complete the procedures. Pap smear and mammography were more likely to be initially accepted by those patients with more years of formal education and were less likely to be completed by those with private insurance coverage. Among a subgroup of 76 patients completing a telephone interview, personal health beliefs were not consistently associated with procedure acceptance or completion. These results suggest that both the initial nonacceptance of procedures and the subsequent barriers to their completion limit the efficacy of cancer screening efforts in the primary-care setting. Future research will be required to develop an explanatory model or to propose a targeted intervention.

Race differences in factorial structures of two measures of subjective well-being

This research examines race differences in the factorial structure of two popular measures of psychological well-being: the Philadelphia Geriatric Center (PGC) Morale Scale and the Life Satisfaction Index A (LSIA). In particular, we view the covariance structure of the items of each scale as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices in the White and the Black samples. Data for the research came from the 1968 National Senior Citizens Survey and the 1974 Harris National Council on Aging Survey, Myths and Reality of Aging in America. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance of both the PGC Morale Scale and the LSIA. Race differences were found in the factorial structure of the PGC Morale Scale, but not in the structure of LSIA. In particular, consistent race differences in measurement error variances were found for two items of the PGC Morale Scale.

Quantitation of anionic sites in glomerular capillary basement membranes of Samoyed dogs with hereditary glomerulopathy

Samoyed hereditary glomerulopathy (SHG) is an X-linked dominant disease characterized by proteinuria and renal failure in affected male dogs. Electron microscopic examination of glomerular capillary basement membranes (GCBM) shows widespread multilaminar splitting of the lamina densa, identical to that in Alport's syndrome. Anionic sites in GCBM of three affected males and five unaffected dogs were labeled using polyethyleneimine to determine whether proteinuria was associated with an alteration in their number. No significant differences were noted in the number of anionic sites in the lamina rara externa, whereas small but statistically significant increases were seen in the number of sites in the lamina rara interna of affected males. In the lamina densa, affected males showed a striking increase in anionic sites, particularly in regions of GCBM which were split. Thus, although proteinuria in some glomerular diseases has been attributed to a reduction in anionic sites in GCBM, this was not so in SHG.

Cross-cultural comparability of the Philadelphia Geriatric Center Morale Scale: an American-Japanese comparison

This study involves an American-Japanese comparison of the factorial structure of the Philadelphia Geriatric Center (PGC) Morale Scale. A model containing 11 of the original PGC Morale Scale items was found to fit both the American and Japanese data adequately. Factorial invariance was analyzed by testing a series of nested hypotheses involving various equivalence constraints. No major differences were found in the 11-item PGC Morale Scale between the American and Japanese data sets.

Effect of age and muscle type on regeneration of neuromuscular synapses in mice

A silver stain was used to investigate the regeneration of nerve terminals in mouse diaphragm, superior gluteus and tensor fasciae latae (TFL) muscles following nerve crush injury at different ages (9-530 days). The development of myelinated terminal branches and the development and elimination of terminal sprouts were little affected by age or muscle type following reinnervation. However, multiple axonal innervation developed on up to 50% of the gluteus and TFL muscle fibres, and this was subsequently eliminated only in the youngest animals.

Self-reported physical health among aged adults

A multiple indicator structural equation model is proposed to delineate the various aspects of self-reported physical health. In particular, it specifies structural linkages among five measures of health including chronic illness, number of sick days, physical self-maintenance, instrumental activities of daily living, and subjective rating of one's own health. The proposed model is evaluated by using data from the 1968 National Senior Citizens Survey. The results support the predictions derived from the proposed model and are consistently replicated across four randomly divided subsamples.

Age differences in the structure of the Philadelphia Geriatric Center Morale Scale

In this research we examined age differences in the factorial structure of the Philadelphia Geriatric Center (PGC) Morale Scale. In particular, we viewed the covariance structure of the PGC Morale Scale items as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices in the young-old (65-74) and the old-old (75 and over) populations. Data for this research came from the 1968 National Senior Citizens Survey. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance of the PGC Morale Scale. Although there are some statistically significant age differences in the factorial structure, substantively they are less important.

Population aging in the People's Republic of China

This paper provides a factual assessment of China's population aging and its social and economic consequences. It is projected that China will have a substantially older population in the middle of the 21st century. Major policy implications concerning old age support and health care have been examined.

Age differences in the structure of the Philadelphia Geriatric Center Morale Scale

In this research we examined age differences in the factorial structure of the Philadelphia Geriatric Center (PGC) Morale Scale. In particular, we viewed the covariance structure of the PGC Morale Scale items as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices in the young-old (65-74) and the old-old (75 and over) populations. Data for this research came from the 1968 National Senior Citizens Survey. Analysis of covariance structures, or LISREL, was used to assess the factorial invariance of the PGC Morale Scale. Although there are some statistically significant age differences in the factorial structure, substantively they are less important.

A structural integration of the Affect Balance Scale and the Life Satisfaction Index A

This study integrates two popular measures of subjective well-being: the Affect Balance Scale (ABS) and the Life Satisfaction Index A (LSIA). Eight ABS items and seven LSIA items are hypothesized to measure four dimensions including congruence, happiness, positive affect, and negative affect. In addition, a second-order factor identified as subjective well-being is postulated to account for the correlations among these four dimensions. This model is examined empirically by using data from the Harris 1974 National Council on Aging survey, Myths and Realities of Aging in America. The proposed formulation is supported and consistently replicated across four randomly divided subsamples.

Sex differences in the structure of the Philadelphia Geriatric Center Morale Scale

This research examined sex differences in the factorial structure of the Philadelphia Geriatric Center Morale Scale. In particular, we view the covariance structure of the scale items as a function of several parameter matrices. We analyzed the factorial invariance by testing hypotheses involving the equivalence constraints of one or more parameter matrices in the male and female populations. Data for this research came from the 1968 National Senior Citizens Survey. Analysis of covariance structures (or LISREL) was used to assess the factorial invariance of the scale. We found some statistically significant sex differences in the first-order factor loadings and measurement error variances. Substantively, however, these differences are less important.

Dimensions of the Life Satisfaction Index A: a structural formulation

This research aimed to clarify the dimensionality of the Life Satisfaction Index A. A multiple indicator structural equation model that includes 11 items loading on three first-order factors and one second-order factor was proposed to delineate the structure of the Life Satisfaction Index A. This model was examined empirically by using data from the 1974 National Council on Aging/Harris survey, Myths and Realities of Aging in America. The proposed formulation was supported and consistently replicated across four randomly divided subsamples.