Fitting longitudinal reduced-rank regression models by alternating least squares

An alternating least squares method for iteratively fitting the longitudinal reduced-rank regression model is proposed. The method uses ordinary least squares and majorization substeps to estimate the unknown parameters in the system and measurement equations of the model. In an example with cross-sectional data, it is shown how the results conform closely to results from eigenanalysis. Optimal scaling of nominal and ordinal variables is added in a third substep, and illustrated with two examples involving cross-sectional and longitudinal data.Financial support by the Institute for Traffic Safety Research (SWOV) in Leidschendam, The Netherlands is gratefully acknowledged.     

Differential effects of priming at the encoding and judgment stage

Two experiments investigated whether the direction of priming effects depends on the processing stage at which the individual links the prime to a trait that is applicable to the evaluation of an ambiguously described target person. In line with previous research, it is hypothesized that assimilation effects will emerge when primes are processed in terms of a trait concept that is applicable to the encoding task. However, when the primes are not processed in applicable trait terms, they may still affect subsequent Judgments if the individual recalls the prime when judging the target along a trait dimension. In this case, the primes may serve as an anchor, resulting in contrast effects. Two experiments, in which subjects were primed with names of prototypically nice or hostile famous individuals under instructions that did or did not prompt subjects to process the prime in applicable trait terms, supported these hypotheses. Implications for the emergence of priming effects in everyday social interaction are discussed.     

Differential effects of identification with family and peers on coping with developmental tasks in adolescence

Adolescents from three Italian cities responded to a questionnaire concerning the particular peer-group with which they were associated and identification with their family, aspects of the process of coping with seven developmental tasks, and demographic characteristics. The participants were 1600 male and female teenagers, with a mean age of 16.28 years, who were approached at schools and various meeting places in three Italian cities. The study shows that effective coping with developmental tasks depends largely on the degree of identification with both family and peer-group. Those who identify with both social groupings show advantages in various critical situations. Adolescents only identifying with either family or peers get emotional and instrumental support from that group but not from the other, thus, they are supported in some critical situations but not in others. Adolescents who are unwilling or unable to identify with their family and/or their peers are less successful in managing the transition to adulthood than others who are close to their parents and peers. Consistent with the findings of previous studies, the type of group adolescents join, be it a formal group or an informal street group, has no significant effect on their coping strategies.     

Reflections on a medical ethics for the future

Recently, the attitude and performance of the physician have been questioned and new codes of medical ethics have been introduced. Any ethics proposed for the future is a scenario reflecting the composer's selectivity. Envisaged ethics of truthful, non-paternalistic, responsible physician-patient interaction will have far-reaching implications for autopsy, euthanasia, abortion, suicide, genetic engineering, transplantation, clinical trials, status of the psychiatric patient, physician immunity and liability. Conflicts between personal and societal medical ethics may continue to be insoluble. A possible projection of the physician's ethics on that of the politician is discussed. A new medical ethics should encompass principles of different creeds and be supranational.     

The relationship of estimated comprehensibility to the rate of connected speech

The relationship between subjective estimates of the comprehensibility of connected, freerunning speech and rate of speech was investigated for each of two types of time-compressed speech: pitch-varying speeded speech and pitch-normalized compressed speech. The midpoints of the resulting functions approximated the values obtained by a previously described speechrate tracking method. For equivalent degrees of comprehensibility, rates were higher for compressed speech than for speeded speech, indicating that estimates are sensitive to the intelligibility of speech. Subjective estimates of comprehensibility of time-compressed speech provide a means of assessing the itelligibility of connected speech.     

Semantic congruity effects in judgments of loudness

This research uses comparative judgments of the relative loudness of sounds to make a critical test of one theory of the mental representation of continuous physical attributes. The first two experiments find a semantic congruity effect, which is an interaction such that subjects can pick the louder of two loud sounds faster than the softer, and the softer of two quiet sounds faster than the louder. According to the theory under test, physical quantities are stored as points on a representational continuum, with a variance as well as a mean placement on it. The theory predicts the semantic congruity effect by assuming that the variance of placement of intensities on the representational continuum is a function of the direction of judgment: a soft sound will have less variance than a loud one when judged for softness and more when judged for loudness. Since the speed of making a judgment increases as variance decreases, the theory predicts a semantic congruity effect. However, for loudness, it can be shown that variance does not change in the manner assumed. The finding of a semantic congruity effect therefore disconfirms the theory. Alternative models are discussed. This research was supported by NSF Grant BNS 78-17442.     

Signalled free-operant avoidance of shock by pigeons pecking a key

Two pigeons were trained to peck a key under a free-operant avoidance schedule. Then, changes in key color signalled the beginning (safe period) and the end (warning period) of the response-shock interval, with a response required to change the key color. Finally, a change in key color signalled the warning period and either a response or a shock reinstated the safe stimulus. During signalled avoidance, response rate was higher during the warning stimulus than during the safe stimulus. More responding tended to occur in the warning stimulus when it was terminated by either a response or a shock than by only a response. In either procedure, response latency during the warning stimulus was a function of the duration of the warning stimulus. In general, response and shock rate were higher during unsignalled than during signalled avoidance. When the warning stimulus was brief, the results were similar to those of unsignalled avoidance. These results confirm previous findings with pigeons, are in general agreement with data provided by other species in studies of signalled avoidance, and thereby indicate the transituationality of the key-pecking operant.     

Cross-cultural model testing: toward a solution of the etic-emic dilemma

A model for the prediction of behavior from attitudinal components, developed by Triandis, was tested with samples of U.S. and Mexican women, and with fertility relevant behaviors. The elements of the model are etic, but the operationalizations of the various variables were done emically. Results support the model in both cultures. While the predictive utility of the model is equivalent in two cultures, there are social class differences on which component of the model is most emphasized. The U.S. upper-middle-class sample and the Mexican upper-middle-class sample emphasized the person's attitude toward the act, while the Mexican lower SES (socio-economic status) sample emphasized the person's normative beliefs (moral obligations).     

The role of anionic, imidic and amidic forms in structure-activity relationships. Conjugation and bacteriostatic activity in sulphonamides.

The electronic structures of anionic, imidic and amidic forms of sulphonamides were investigated and compared by means of I.R., Raman and U.V. spectroscopy. Indices reflecting the electronic situation of the common moiety p-H2N-C6H4-SO2 was a whole, although not necessarily related, physically, to any event taking place in the biological processes, were found to correlate with the in vitro bacteriostatic activity of the specific individual forms. The influence of N1-substituents both on the SO2 electronic features and on the coupling between the para amino group and the phenyl ring was discussed. It resulted that the most active chemical species, in this class of compounds, are characterized, electronically, by the most electron-rich common moiety and, in particular, by the most negative oxygens in the SO2 group and the most available (less engaged) lone-pair in the rho-amino group. These conclusions give a new settlement both to the problem of resonance and to the relation between resonance effects and bacteriostatic activity in this class of compounds.