ABSTRACT Using data from a random sample of Latino students in California, tracked throughout the... more ABSTRACT Using data from a random sample of Latino students in California, tracked throughout their elementary and middle school years, this paper examines ways in which outcomes vary for students of similar language and socioeconomic background who are initially instructed in their native language in transitional bilingual programs. As the students made the transition to instruction in English, which took place for most students in the sample between Grades 2 and 4, all students experienced an abrupt decline in performance on standardized reading test scores in English. However, performance trajectories after transition took markedly different paths, with higher achievers returning to pre-transition rates of performance as lower achievers continued an achievement decline that began for many while still being instructed in Spanish. The paper also examines school factors potentially associated with variations in performance (school-wide reform and strong kindergarten program) for subsets of the sample.
T HROUGH statistical analysis of a great number of ~entences, we confirm one major difference bet... more T HROUGH statistical analysis of a great number of ~entences, we confirm one major difference between Latin and Greek word order, and we explore the ramifications of this observation for some possible cases of word-order transference between Latin and Greek. The difference to which we refer concerns the positioning of the accusative direct object before or after the verb governing it. That there is a significant difference in the Greek and Latin distributions will come as no surprise to Classical linguists: it has long been observed that Latin has a greater tendency to place the verb at the end of the clause than does Greek. 1 From this fact alone one might predict that the direct object in Latin is more likely to precede than to follow the verb on which it depends than is the case in Greekalthough, logically, this need not be the case. In our study we tested this prediction empirically by tabulating the direct object distributions in sixty passages written by fifteen Latin and ten Greek prose authors. Each passage was randomly selected in the text of an author. We analyzed the first one hundred direct objects in the accusative CLUSTER 1: MEMBERS CASE DISTANCE CASE DISTANCE Varro Res Rust. 9.18 Ammianus Marcellinus !8 !.18 Cicero De Off 3a 4.!8 Pliny (Jr.) Epist. 9.18 Cicero De Nat. Deor. 1.82 Pliny the Elder NH 36 6.65 3 On the basic concepts of cluster analysis used in this and the preceding paragraph, see Everitt 1993: 1-10. 4 On K-means clustering, see Affifi and Clark 1984: 394-397. The algorithm is described on pages 394-395 as follows: "(1) Divide the data into K initial clusters. The members of these clusters may be specified by the user or may be selected by the program, according to an arbitrary procedure. (2) Calculate the means or centroids of each of the K clusters. (3) For a given case, calculate its distance to each centroid. If the case is closest to the centroid of its own cluster, leave it in that cluster; otherwise, reassign it to the cluster whose centroid is closest to it. (4) Repeat step 3 for each case. (5) Repeat steps 2, 3, and 4 until no cases are reassigned." 5 Cf. Everitt 1993: 55: "in a hierarchic classification the data are not partitioned into a particular number of classes or clusters at a single step." 6 On the logic of setting K at its "natural" value in an initial analysis of the data, see Affifi and Clark 1984: 400.
To predict posttraumatic stress symptoms in parents of survivors of childhood cancer, using as pr... more To predict posttraumatic stress symptoms in parents of survivors of childhood cancer, using as predictors the following: personality (trait anxiety); current family and individual variables (perceived life threat, perceived treatment intensity, life events, family functioning, and social ...
Electrophysiological correlates of focused attention were studied in 13 schizophrenic and 19 age-... more Electrophysiological correlates of focused attention were studied in 13 schizophrenic and 19 age- and gender-matched children. Subjects performed a version of the Continuous Performance Task (CPT) in which a target was designated as any digit from 0 through 9 occurring on two successive stimulus presentations. Signal digits were surrounded by distractor digits which varied in position, value, and number. Event-related potentials (ERPs) elicited by each stimulus of a target pair were recorded from midline and homologous parietal, temporal, and occipital electrode placements. Schizophrenic children made significantly more errors of omission and commission than normal children. The amplitude and time course of the intertrial CNV was the same for both groups. There was a circumscribed amplitude asymmetry, left smaller than right, for the P1/N1 and P2 measures which was greater in normal than in schizophrenic children. The P3 component was significantly larger to the second stimulus of the target pair than to the first for both groups, and larger for the normal than the schizophrenic children to both stimuli.
This article considers repeated regression experiments wherein the regression parameters vary acc... more This article considers repeated regression experiments wherein the regression parameters vary according to a stationary stochastic process with known covariance structure. Expressions are derived for best linear estimators and predictors of linear functions of the regression parameters.
This study assessed 5-year changes in ambulatory blood pressure (ABP) in healthy, older individua... more This study assessed 5-year changes in ambulatory blood pressure (ABP) in healthy, older individuals and determined the extent to which it could be predicted from earlier BP measures and other cardiovascular risk factors. A total of 162 men and women, aged 55 to 79 years, with no prior medical disorders, completed a medical examination and two 24-h ABP sessions. The procedures were repeated 5 years later in 80% (130) of these subjects. A modified hierarchical regression analysis was used to determine whether initial ABP and casual blood pressure (CBP) measures and demographic and physical examination data could predict ABP in 5 years. The CBP and most ABP levels during waking and sleep increased after 5 years. However, CBP remained in the normotensive range for 73% of the subjects. The ABP variability tended to decrease over time. The ABP and CBP measures accounted for at least 50% of the variance in the prediction of ABP level after 5 years. In comparison, the predictability of ABP ...
This study examines retrospective reports of factors anticipated to impact first intercourse in a... more This study examines retrospective reports of factors anticipated to impact first intercourse in a random sample of 897 Jamaican women, and contributes to our understanding of the relationship between sexual risk, knowledge, and economic and demographic correlates of first intercourse. A relationship between initiation of intercourse prior to the age of consent (16 years) and factors occurring at or around the time of first intercourse was found. Early initiators were more likely to have had less early family stability and to have experienced menarche at a younger age than late initiators. Although early initiators of intercourse were more likely to report lower socioeconomic status, less STD knowledge, and greater numbers of pregnancies, they were no more likely to report more sexual partners than women who engaged in first intercourse after the age of consent, and had a greater number of long-term relationships. Regardless of age of first intercourse, women need to be made aware of...
The purposes of this study were to investigate the attentional characteristics of hyperactive chi... more The purposes of this study were to investigate the attentional characteristics of hyperactive children, the relationship of subjective and objective measures of these characteristics, and the effects of methylphenidate on these measures of attention. Forty-five hyperactive children, ages 6 to 10 years, were entered into an 18-week study of the effects of methylphenidate (Ritalin) on attention. Measures included rating scales completed by teachers and parents and a vigilance task. All measures reflected significant changes during the period of investigation. Attention and behavior were significantly improved under drug conditions and significantly worsened when methylphenidate was discontinued. However, only performance on the objective measure returned to predrug levels; final off-drug parent and teacher ratings remained improved over initial reports. Parent ratings of behavior, and specifically of children's ability to attend, were unrelated to equivalent teacher ratings. Teach...
Based on hypotheses generated during clinical interviews with 80 women with a lifetime history of... more Based on hypotheses generated during clinical interviews with 80 women with a lifetime history of bulimia nervosa (BN), we designed an instrument for assessing the extent to which women with BN report parental intrusiveness and breakdown of appropriate role boundaries during their adolescent development. Through an iterative process of item generation and scale administration, the Parental Intrusiveness Rating Scale (PIRS), consisting of 20 maternal items and 20 paternal items, was developed. Maternal subscales include Invasion of Privacy, Jealousy and Competition, and Overconcern with the Daughter's Eating, Weight, and Shape. Paternal subscales include Invasion of Privacy, Seductiveness, and Overconcern with the Daughter's Eating, Weight, and Shape. We validated the instrument using a subset of the above BN and comparison women (ns = 55 and 33, respectively), as well as an independent sample of women with BN and college comparison subjects (ns = 31 and 540, respectively). Parental intrusiveness scores were significantly positively correlated with disturbed relationships in the family of origin of our initial cohort. Reliability analyses, both test-retest and item-scale correlations, revealed adequate to strong statistical associations in the combined sample. The PIRS promises to enrich our understanding of problematic parental behaviors among women who develop BN and allows us to broaden the conceptualization of familial risk factors for this disorder.
Cultural Diversity and Ethnic Minority Psychology, 1999
This article describes HIV-related gynecological, reproductive, and sexual health of 290 HIV-posi... more This article describes HIV-related gynecological, reproductive, and sexual health of 290 HIV-positive African American, Latina, European American, Asian/Pacific Islander, and Native American women 18 years of age or older. Using baseline data from the University of ...
Startle modulation in young adult men, by continuous background tone and its offset, a 2-s sustai... more Startle modulation in young adult men, by continuous background tone and its offset, a 2-s sustained tone and its offset, and the onset of a 25-ms tone pip were compared. Tone (75dB 1000 Hz) offset and onset occurred either 2000 ms or 100-120 ms before the startle stimuli (104dB (SPL), 50-ms white noise bursts). Blink amplitude and latency were unaffected by continuous background tone. Blink amplitude was reliably inhibited by 100-ms offset of both the continuous background tone and the 2-s sustained tone or 120-ms onset of the tone pip, whereas effects on latency were more variable. Facilitation of blink amplitude and latency was significant but weak and only following the 2-s sustained tone, and only with respect to one of two experimental contexts. These findings support those of others and suggest that startle inhibition results from activation of neurons responding to transient environmental changes. The degree of inhibition appears to be related to stimulus value. Startle amplitude facilitation following long sustained prestimulation intervals is dependent on experimental context. Overall latency and amplitude modulation tend to be concordant, leading to the conclusion that the mechanism(s) underlying both are context dependent and linked in the adult human.
The purpose of this paper is to show that the familiar principal component analysis (PCA) of even... more The purpose of this paper is to show that the familiar principal component analysis (PCA) of event-related potentials is identical to an easily formulated least squares method. This correspondence permits interpretation of several criticisms of PCA and clearer presentation of its strengths and shortcomings. Because data analysis based on PCA compares amplitudes of empirically derived components, it is necessary that the shape of the components be similar under the experimental conditions. We present and illustrate a statistical method for comparison of principal components across groups and between conditions within subjects.
This note provides a statistical-graphical method for the evaluation of the statistical significa... more This note provides a statistical-graphical method for the evaluation of the statistical significance of difference potentials from a group of subjects, and for the comparison of difference potentials between two groups. A table of the lengths of statistically significant intervals for various sampling interval lengths, numbers of subjects, and autocorrelation parameters is presented.
The majority of anatomic and neuroimaging studies in adult-onset schizophrenia demonstrate decrea... more The majority of anatomic and neuroimaging studies in adult-onset schizophrenia demonstrate decreased volumes of the medial temporal lobe when compared with findings in normal individuals. The goal of this study was to investigate the hypothesis that subjects with childhood-onset schizophrenia would show decreased volumes of the medial temporal lobe when compared to normal children. Thirteen children meeting DSM-III-R criteria for schizophrenia (mean age 14.2+/-3.8 years) and 20 normal children (mean age 12.0+/-2.8 years) were investigated. MRI scans were performed on a 1.5-T GE Signa MR scanner using a coronal plane SPGR at 1.4-mm slice thickness. Volumes were assessed by manually tracing bilateral hippocampus, amygdala and temporal lobes. After adjustment for age and total brain volume, the amygdala was significantly larger in the schizophrenics than in the control subjects, and this volume increase was more pronounced on the left side. Hippocampus volumes did not differ significantly across groups. There was a nearly significant left-greater-than-right asymmetry of the amygdala in the schizophrenic group but not in the normal group. A nearly significant right-greater-than-left asymmetry was found in the anterior hippocampus for both schizophrenic and control groups. These findings are consistent with previous reports of at least initial sparing of temporal lobe regions in childhood-onset schizophrenia.
Correlations between neonatal body weight, and body weight and several brain parameters at 30 day... more Correlations between neonatal body weight, and body weight and several brain parameters at 30 days of age were studied in normal rats. At 30 days ('adolescence') cortex has already reached its final thickness and the rat exhibits long-term memory. Brain parameters included cerebral weight, DNA, protein and cholesterol contents and densities, as well as cortical and cerebral dimensions (cerebral sections). As expected, most of these parameters in 30-day-old animals were significantly correlated with each other. Unexpectedly, neonatal body weight was also significantly correlated with cholesterol content and density at 30 days, as well as with cortical and cerebral dimensions at 30 days. Thus, statistically, neonatal body weight already predetermines the extent of neuronal (cerebral) development at adolescence (30 days). This finding also makes it possible to make at birth statistical predictions about future brain development without having to sacrifice neonatal animals.
ABSTRACT Using data from a random sample of Latino students in California, tracked throughout the... more ABSTRACT Using data from a random sample of Latino students in California, tracked throughout their elementary and middle school years, this paper examines ways in which outcomes vary for students of similar language and socioeconomic background who are initially instructed in their native language in transitional bilingual programs. As the students made the transition to instruction in English, which took place for most students in the sample between Grades 2 and 4, all students experienced an abrupt decline in performance on standardized reading test scores in English. However, performance trajectories after transition took markedly different paths, with higher achievers returning to pre-transition rates of performance as lower achievers continued an achievement decline that began for many while still being instructed in Spanish. The paper also examines school factors potentially associated with variations in performance (school-wide reform and strong kindergarten program) for subsets of the sample.
T HROUGH statistical analysis of a great number of ~entences, we confirm one major difference bet... more T HROUGH statistical analysis of a great number of ~entences, we confirm one major difference between Latin and Greek word order, and we explore the ramifications of this observation for some possible cases of word-order transference between Latin and Greek. The difference to which we refer concerns the positioning of the accusative direct object before or after the verb governing it. That there is a significant difference in the Greek and Latin distributions will come as no surprise to Classical linguists: it has long been observed that Latin has a greater tendency to place the verb at the end of the clause than does Greek. 1 From this fact alone one might predict that the direct object in Latin is more likely to precede than to follow the verb on which it depends than is the case in Greekalthough, logically, this need not be the case. In our study we tested this prediction empirically by tabulating the direct object distributions in sixty passages written by fifteen Latin and ten Greek prose authors. Each passage was randomly selected in the text of an author. We analyzed the first one hundred direct objects in the accusative CLUSTER 1: MEMBERS CASE DISTANCE CASE DISTANCE Varro Res Rust. 9.18 Ammianus Marcellinus !8 !.18 Cicero De Off 3a 4.!8 Pliny (Jr.) Epist. 9.18 Cicero De Nat. Deor. 1.82 Pliny the Elder NH 36 6.65 3 On the basic concepts of cluster analysis used in this and the preceding paragraph, see Everitt 1993: 1-10. 4 On K-means clustering, see Affifi and Clark 1984: 394-397. The algorithm is described on pages 394-395 as follows: "(1) Divide the data into K initial clusters. The members of these clusters may be specified by the user or may be selected by the program, according to an arbitrary procedure. (2) Calculate the means or centroids of each of the K clusters. (3) For a given case, calculate its distance to each centroid. If the case is closest to the centroid of its own cluster, leave it in that cluster; otherwise, reassign it to the cluster whose centroid is closest to it. (4) Repeat step 3 for each case. (5) Repeat steps 2, 3, and 4 until no cases are reassigned." 5 Cf. Everitt 1993: 55: "in a hierarchic classification the data are not partitioned into a particular number of classes or clusters at a single step." 6 On the logic of setting K at its "natural" value in an initial analysis of the data, see Affifi and Clark 1984: 400.
To predict posttraumatic stress symptoms in parents of survivors of childhood cancer, using as pr... more To predict posttraumatic stress symptoms in parents of survivors of childhood cancer, using as predictors the following: personality (trait anxiety); current family and individual variables (perceived life threat, perceived treatment intensity, life events, family functioning, and social ...
Electrophysiological correlates of focused attention were studied in 13 schizophrenic and 19 age-... more Electrophysiological correlates of focused attention were studied in 13 schizophrenic and 19 age- and gender-matched children. Subjects performed a version of the Continuous Performance Task (CPT) in which a target was designated as any digit from 0 through 9 occurring on two successive stimulus presentations. Signal digits were surrounded by distractor digits which varied in position, value, and number. Event-related potentials (ERPs) elicited by each stimulus of a target pair were recorded from midline and homologous parietal, temporal, and occipital electrode placements. Schizophrenic children made significantly more errors of omission and commission than normal children. The amplitude and time course of the intertrial CNV was the same for both groups. There was a circumscribed amplitude asymmetry, left smaller than right, for the P1/N1 and P2 measures which was greater in normal than in schizophrenic children. The P3 component was significantly larger to the second stimulus of the target pair than to the first for both groups, and larger for the normal than the schizophrenic children to both stimuli.
This article considers repeated regression experiments wherein the regression parameters vary acc... more This article considers repeated regression experiments wherein the regression parameters vary according to a stationary stochastic process with known covariance structure. Expressions are derived for best linear estimators and predictors of linear functions of the regression parameters.
This study assessed 5-year changes in ambulatory blood pressure (ABP) in healthy, older individua... more This study assessed 5-year changes in ambulatory blood pressure (ABP) in healthy, older individuals and determined the extent to which it could be predicted from earlier BP measures and other cardiovascular risk factors. A total of 162 men and women, aged 55 to 79 years, with no prior medical disorders, completed a medical examination and two 24-h ABP sessions. The procedures were repeated 5 years later in 80% (130) of these subjects. A modified hierarchical regression analysis was used to determine whether initial ABP and casual blood pressure (CBP) measures and demographic and physical examination data could predict ABP in 5 years. The CBP and most ABP levels during waking and sleep increased after 5 years. However, CBP remained in the normotensive range for 73% of the subjects. The ABP variability tended to decrease over time. The ABP and CBP measures accounted for at least 50% of the variance in the prediction of ABP level after 5 years. In comparison, the predictability of ABP ...
This study examines retrospective reports of factors anticipated to impact first intercourse in a... more This study examines retrospective reports of factors anticipated to impact first intercourse in a random sample of 897 Jamaican women, and contributes to our understanding of the relationship between sexual risk, knowledge, and economic and demographic correlates of first intercourse. A relationship between initiation of intercourse prior to the age of consent (16 years) and factors occurring at or around the time of first intercourse was found. Early initiators were more likely to have had less early family stability and to have experienced menarche at a younger age than late initiators. Although early initiators of intercourse were more likely to report lower socioeconomic status, less STD knowledge, and greater numbers of pregnancies, they were no more likely to report more sexual partners than women who engaged in first intercourse after the age of consent, and had a greater number of long-term relationships. Regardless of age of first intercourse, women need to be made aware of...
The purposes of this study were to investigate the attentional characteristics of hyperactive chi... more The purposes of this study were to investigate the attentional characteristics of hyperactive children, the relationship of subjective and objective measures of these characteristics, and the effects of methylphenidate on these measures of attention. Forty-five hyperactive children, ages 6 to 10 years, were entered into an 18-week study of the effects of methylphenidate (Ritalin) on attention. Measures included rating scales completed by teachers and parents and a vigilance task. All measures reflected significant changes during the period of investigation. Attention and behavior were significantly improved under drug conditions and significantly worsened when methylphenidate was discontinued. However, only performance on the objective measure returned to predrug levels; final off-drug parent and teacher ratings remained improved over initial reports. Parent ratings of behavior, and specifically of children's ability to attend, were unrelated to equivalent teacher ratings. Teach...
Based on hypotheses generated during clinical interviews with 80 women with a lifetime history of... more Based on hypotheses generated during clinical interviews with 80 women with a lifetime history of bulimia nervosa (BN), we designed an instrument for assessing the extent to which women with BN report parental intrusiveness and breakdown of appropriate role boundaries during their adolescent development. Through an iterative process of item generation and scale administration, the Parental Intrusiveness Rating Scale (PIRS), consisting of 20 maternal items and 20 paternal items, was developed. Maternal subscales include Invasion of Privacy, Jealousy and Competition, and Overconcern with the Daughter's Eating, Weight, and Shape. Paternal subscales include Invasion of Privacy, Seductiveness, and Overconcern with the Daughter's Eating, Weight, and Shape. We validated the instrument using a subset of the above BN and comparison women (ns = 55 and 33, respectively), as well as an independent sample of women with BN and college comparison subjects (ns = 31 and 540, respectively). Parental intrusiveness scores were significantly positively correlated with disturbed relationships in the family of origin of our initial cohort. Reliability analyses, both test-retest and item-scale correlations, revealed adequate to strong statistical associations in the combined sample. The PIRS promises to enrich our understanding of problematic parental behaviors among women who develop BN and allows us to broaden the conceptualization of familial risk factors for this disorder.
Cultural Diversity and Ethnic Minority Psychology, 1999
This article describes HIV-related gynecological, reproductive, and sexual health of 290 HIV-posi... more This article describes HIV-related gynecological, reproductive, and sexual health of 290 HIV-positive African American, Latina, European American, Asian/Pacific Islander, and Native American women 18 years of age or older. Using baseline data from the University of ...
Startle modulation in young adult men, by continuous background tone and its offset, a 2-s sustai... more Startle modulation in young adult men, by continuous background tone and its offset, a 2-s sustained tone and its offset, and the onset of a 25-ms tone pip were compared. Tone (75dB 1000 Hz) offset and onset occurred either 2000 ms or 100-120 ms before the startle stimuli (104dB (SPL), 50-ms white noise bursts). Blink amplitude and latency were unaffected by continuous background tone. Blink amplitude was reliably inhibited by 100-ms offset of both the continuous background tone and the 2-s sustained tone or 120-ms onset of the tone pip, whereas effects on latency were more variable. Facilitation of blink amplitude and latency was significant but weak and only following the 2-s sustained tone, and only with respect to one of two experimental contexts. These findings support those of others and suggest that startle inhibition results from activation of neurons responding to transient environmental changes. The degree of inhibition appears to be related to stimulus value. Startle amplitude facilitation following long sustained prestimulation intervals is dependent on experimental context. Overall latency and amplitude modulation tend to be concordant, leading to the conclusion that the mechanism(s) underlying both are context dependent and linked in the adult human.
The purpose of this paper is to show that the familiar principal component analysis (PCA) of even... more The purpose of this paper is to show that the familiar principal component analysis (PCA) of event-related potentials is identical to an easily formulated least squares method. This correspondence permits interpretation of several criticisms of PCA and clearer presentation of its strengths and shortcomings. Because data analysis based on PCA compares amplitudes of empirically derived components, it is necessary that the shape of the components be similar under the experimental conditions. We present and illustrate a statistical method for comparison of principal components across groups and between conditions within subjects.
This note provides a statistical-graphical method for the evaluation of the statistical significa... more This note provides a statistical-graphical method for the evaluation of the statistical significance of difference potentials from a group of subjects, and for the comparison of difference potentials between two groups. A table of the lengths of statistically significant intervals for various sampling interval lengths, numbers of subjects, and autocorrelation parameters is presented.
The majority of anatomic and neuroimaging studies in adult-onset schizophrenia demonstrate decrea... more The majority of anatomic and neuroimaging studies in adult-onset schizophrenia demonstrate decreased volumes of the medial temporal lobe when compared with findings in normal individuals. The goal of this study was to investigate the hypothesis that subjects with childhood-onset schizophrenia would show decreased volumes of the medial temporal lobe when compared to normal children. Thirteen children meeting DSM-III-R criteria for schizophrenia (mean age 14.2+/-3.8 years) and 20 normal children (mean age 12.0+/-2.8 years) were investigated. MRI scans were performed on a 1.5-T GE Signa MR scanner using a coronal plane SPGR at 1.4-mm slice thickness. Volumes were assessed by manually tracing bilateral hippocampus, amygdala and temporal lobes. After adjustment for age and total brain volume, the amygdala was significantly larger in the schizophrenics than in the control subjects, and this volume increase was more pronounced on the left side. Hippocampus volumes did not differ significantly across groups. There was a nearly significant left-greater-than-right asymmetry of the amygdala in the schizophrenic group but not in the normal group. A nearly significant right-greater-than-left asymmetry was found in the anterior hippocampus for both schizophrenic and control groups. These findings are consistent with previous reports of at least initial sparing of temporal lobe regions in childhood-onset schizophrenia.
Correlations between neonatal body weight, and body weight and several brain parameters at 30 day... more Correlations between neonatal body weight, and body weight and several brain parameters at 30 days of age were studied in normal rats. At 30 days ('adolescence') cortex has already reached its final thickness and the rat exhibits long-term memory. Brain parameters included cerebral weight, DNA, protein and cholesterol contents and densities, as well as cortical and cerebral dimensions (cerebral sections). As expected, most of these parameters in 30-day-old animals were significantly correlated with each other. Unexpectedly, neonatal body weight was also significantly correlated with cholesterol content and density at 30 days, as well as with cortical and cerebral dimensions at 30 days. Thus, statistically, neonatal body weight already predetermines the extent of neuronal (cerebral) development at adolescence (30 days). This finding also makes it possible to make at birth statistical predictions about future brain development without having to sacrifice neonatal animals.
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Papers by Donald Guthrie