Showing papers by "San Diego State University published in 1995"

Variability in Early Communicative Development

Abstract: Data from parent reports on 1,803 children--derived from a normative study of the MacArthur Communicative Development Inventories (CDIs)--are used to describe the typical course and the extent of variability in major features of communicative development between 8 and 30 months of age. The two instruments, one designed for 8-16-month-old infants, the other for 16-30-month-old toddlers, are both reliable and valid, confirming the value of parent reports that are based on contemporary behavior and a recognition format. Growth trends are described for children scoring at the 10th-, 25th-, 50th-, 75th-, and 90th-percentile levels on receptive and expressive vocabulary, actions and gestures, and a number of aspects of morphology and syntax. Extensive variability exists in the rate of lexical, gestural, and grammatical development. The wide variability across children in the time of onset and course of acquisition of these skills challenges the meaningfulness of the concept of the modal child. At the same time, moderate to high intercorrelations are found among the different skills both concurrently and predictively (across a 6-month period). Sex differences consistently favor females; however, these are very small, typically accounting for 1%-2% of the variance. The effects of SES and birth order are even smaller within this age range. The inventories offer objective criteria for defining typicality and exceptionality, and their cost effectiveness facilitates the aggregation of large data sets needed to address many issues of contemporary theoretical interest. The present data also offer unusually detailed information on the course of development of individual lexical, gestural, and grammatical items and features. Adaptations of the CDIs to other languages have opened new possibilities for cross-linguistic explorations of sequence, rate, and variability of communicative development.

Predictive vegetation mapping: geographic modelling of biospatial patterns in relation to environmental gradients:

Abstract: Predictive vegetation mapping can be defined as predicting the geographic distribution of the vegetation composition across a landscape from mapped environmental variables. Comput erized predictive vegetation mapping is made possible by the availability of digital maps of topography and other environmental variables such as soils, geology and climate variables, and geographic information system software for manipulating these data. Especially important to predictive vegetation mapping are interpolated climatic variables related to physiological tolerances, and topographic variables, derived from digital elevation grids, related to site energy and moisture balance. Predictive vegetation mapping is founded in ecological niche theory and gradient analysis, and driven by the need to map vegetation patterns over large areas for resource conservation planning, and to predict the effects of environmental change on vegetation distributions. Predictive vegetation mapping has advanced over the past two decades espe...

Schemas in Problem Solving

Abstract: Preface Acknowledgements Part I. Fundamentals: 1. Schema roots 2. The nature of a schema 3. The schemas of arithmetic story problems Part II. Schemas and Instruction: 4. Theoretical issues for instruction 5. The story problem solver and the problem solving environment: two examples of schema-based instruction Part III. Learning from Instruction: 6. Learning and schema theory 7. Learning from schema-based instruction 8. The acquisition of planning knowledge 9. The diagram: marker and template Part IV. Schemas and Assessment: 10. Schema-based assessment 11. Assessment in SPS and PSE Part V. Schema Models: 12. Production systems, neural networks and hybrid models 13. The performance model 14. The learning model 15. The full schema model 16. Some concluding remarks on schema theory Notes References Name index Subject index.

Patterns and regulation of mycorrhizal plant and fungal diversity

Abstract: The diversity of mycorrhizal fungi does not follow patterns of plant diversity, and the type of mycorrhiza may regulate plant species diversity. For instance, coniferous forests of northern latitudes may have more than 1000 species of ectomycorrhizal (EM) fungi where only a few ectomycorrhizal plant species dominate, but there are fewer than 25 species of arbuscular mycorrhizal (AM) fungi in tropical deciduous forest in Mexico with 1000 plant species. AM and EM fungi are distributed according to biome, with AM fungi predominant in arid and semiarid biomes, and EM fungi predominant in mesic biomes. In addition, AM fungi tend to be more abundant in soils of low organic matter, perhaps explaining their predominance in moist tropical forest, and EM fungi generally occur in soils with higher surface organic matter.

Abnormalities of the Corpus Callosum in Children Prenatally Exposed to Alcohol

Abstract: For 20 years, it has been known that fetal alcohol syndrome (FAS) is associated with abnormal brain development. Early autopsy studies point to the corpus callosum as one area affected by heavy alcohol exposure. Little is known, however, about the integrity of the brain in alcohol-exposed children who survive the perinatal period. This study was designed to assess the corpus callosum in living children exposed to high doses of alcohol prenatally. Thirteen children with histories of significant prenatal alcohol exposure and 12 normal control children were evaluated using magnetic resonance imaging. Using the midsagittal section, images were measured for the area of the corpus callosum using a computer-assisted measurement technique. In addition to the overall area, five equiangular regions were determined for each corpus callosum. Of the 13 alcohol-exposed children assessed, two had agenesis of the corpus callosum. The remaining alcohol-exposed children had significantly smaller overall callosal areas, as well as smaller regional areas of four of the five callosal regions, when compared with the normal control children. Importantly, when corrected for brain size, three of the five callosal regions were still smaller in the alcohol-exposed children, although overall area of the corpus callosum was no longer significantly different. These results suggest that prenatal exposure to high levels of alcohol is associated with abnormalities of the corpus callosum. They verify callosal agenesis in children with FAS, which previously had only been noted in autopsy reports.(ABSTRACT TRUNCATED AT 250 WORDS)

Burnout, self- and supervisor-rated job performance, and absenteeism among nurses.

Abstract: This study examined how job stress and work support predict the experience of burnout and how burnout is related to absenteeism and job performance in a sample of 73 registered nurses. The current study expanded on previous findings by including supervisor ratings of performance and employee records of absenteeism in addition to self-report measures. It also examined the extent to which burnout may mediate the relationships of job stress and social support with these performance indicators. Analyses indicated that levels of work support and job stress were both significant predictors of burnout. Additionally, higher burnout levels were significantly associated with poorer self-rated and supervisor-rated job performance, more sick leave, and more reported absences for mental health reasons. Finally, further analyses suggest that level of burnout served as a mediator of the relationships between social support and self-rated job performance, absences for mental health reasons, and intentions to quit. The findings suggest that burnout not only may negatively impact healthcare providers, but also may influence objective absenteeism and supervisor perceptions of employee performance.

Peasant and Nation: The Making of Postcolonial Mexico and Peru

Abstract: Peasant and Nation offers a major new statement on the making of national politics. Comparing the popular political cultures and discourses of postcolonial Mexico and Peru, Florencia Mallon provides a groundbreaking analysis of their effect on the evolution of these nation states. As political history from a variety of subaltern perspectives, the book takes seriously the history of peasant thought and action and the complexity of community politics. It reveals the hierarchy and the heroism, the solidarity and the surveillance, the exploitation and the reciprocity, that coexist in popular political struggle. With this book Mallon not only forges a new path for Latin American history but challenges the very concept of nationalism. Placing it squarely within the struggles for power between colonized and colonizing peoples, she argues that nationalism must be seen not as an integrated ideology that puts the interest of the nation above all other loyalties, but as a project for collective identity over which many political groups and coalitions have struggled. Ambitious and bold, Peasant and Nation both draws on monumental archival research in two countries and enters into spirited dialogue with the literatures of post-colonial studies, gender studies, and peasant studies.

Early acquisition of verbs in Korean: a cross-linguistic study

Abstract: This cross-linguistic study investigates children's early lexical development in English and Korean, and compares caregivers' linguistic input in the two languages. In Study 1, the lexical development of nine Korean children was followed from 1;2 to 1;10 by monthly visits and maternal reports. These Korean data were compared to previously collected English longitudinal data. We find that: (1) Korean children as young as 1;3 use verbs productively with appropriate inflections. (2) Seven of the nine children show a verb spurt at around 1;7; for six of these children the verb spurt occurs before the noun spurt. No such early verb spurt is found in the English data. Unlike in English, both verbs and nouns in Korean are dominant categories from the single-word stage. (3) Korean children express language-specific distinctions of locative actions with verbs. Study 2, a crosslinguistic study of caregivers' input in English and Korean, shows that Korean mothers provide more action verbs but fewer object nouns than American mothers. Also, Korean mothers engage in activity-oriented discourse significantly more than American mothers. Our study suggests that verbs are accessible to children from the beginning, and that they may be acquired early in children who are encouraged to do so by their language-specific grammar and input.

Automated real-time structure health monitoring via signature pattern recognition

Abstract: C. LiangDept. of Mechanical EngineeringSan Diego State UniversitySan Diego, CA 92182-0191ABSTRACTDescribed in this paper are the details of an automated real-time structure health monitoring system. The system is based onstructural signature pattern recognition. It uses an array ofpiezoceramic (PZ1) patches bonded to the structure as integratedsensor-actuators, an electric impedance analyzer for structural frequency response function (FRF) acquisition and a PC forcontrol and graphic display. An assembled 3-bay truss structure is employed as a test bed. Two issues, the localization ofsensing area and the sensor temperature drift, which are Critical for the sneess of this technique are addressed and a novelapproach of providing temperature compensation using probability correlation function is presentecL Due to the negligibleweight and size of the solid-state sensor array and its ability to sense incipient-type damage, the system can eventually beimplemented on many types of structures such as aircraft, spacecraft, large-span dome roof and steel bridges requiring multi-location and real-time health monitoring1. INTRODUCTIONNondestructive evaluation of structural integrity, or health monitoring, of important structures, such as truss-based sceframe, is of great interest to civil and spae engineering community. To date, many approahes based on modal analysis, orsystem identification have been investigated to assess the damage of a working truss. Most of them explore the fact thatdamage to truss member or its connections generally leads to changes in the modal stiffness matrix of the structure23 Yet,few of them exhibit engineering feasibility because of the low reliability in locating the damage and the requirement ofcomplicated modeling, intensive computation and sophisticated instrumentation.Examination of the mechanical impedance of a structure at the location of interest and comparing it with pre-saved data base

Age-structured and two-delay models for erythropoiesis

Abstract: An age-structured model is developed for erythropoiesis and is reduced to a system of threshold-type differential delay equations using the method of characteristics. Under certain assumptions, this model can be reduced to a system of delay differential equations with two delays. The parameters in the system are estimated from experimental data, and the model is simulated for a normal human subject following a loss of blood. The characteristic equation of the two-delay equation is analyzed and shown to exhibit Hopf bifurcations when the destruction rate of erythrocytes is increased. A numerical study for a rabbit with autoimmune hemolytic anemia is performed and compared with experimental data.

Unawareness of Smell Loss in Normal Aging and Alzheimer's Disease: Discrepancy between Self-Reported and Diagnosed Smell Sensitivity

Abstract: Awareness of loss in smell sensitivity was assessed in 80 normal elderly subjects, 80 patients with probable Alzheimer's disease (AD), and 80 patients with sinusitis by comparing measured smell sensitivity to questionnaire-based, self-reported sensitivity. Both AD patients and sinusitis patients had significantly poorer diagnosed smell sensitivity than the normal elderly. Both patient groups had thresholds which on average were about nine times more concentrated than those of the normal elderly. However, 74% of the AD patients and 77% of the normal elderly with smell loss reported normal smell sensitivity. In contrast, only 8% of the sinusitis patients with loss reported normal smell sensitivity.

SeaWiFS technical report series. Volume 25: Ocean optics protocols for SeaWiFS validation, revision 1

Abstract: This report presents protocols for measuring optical properties, and other environmental variables, to validate the radiometric performance of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), and to develop and validate bio-optical algorithms for use with SeaWiFS data. The protocols are intended to establish foundations for a measurement strategy to verify the challenging SeaWiFS uncertainty goals of 5 percent in water-leaving radiances and 35 percent in chlorophyll alpha concentration. The protocols first specify the variables which must be measured, and briefly review the rationale for measuring each variable. Subsequent chapters cover detailed protocols for instrument performance specifications, characterizing and calibrating instruments, methods of making measurements in the field, and methods of data analysis. These protocols were developed at a workshop sponsored by the SeaWiFS Project Office (SPO) and held at the Naval Postgraduate School in Monterey, California (9-12 April 1991). This report began as the proceedings of the workshop, as interpreted and expanded by the authors and reviewed by workshop participants and other members of the bio-optical research community. The protocols are an evolving prescription to allow the research community to approach the unprecedented measurement uncertainties implied by the SeaWiFS goals; research and development are needed to improve the state-of-the-art in specific areas. These protocols should be periodically revised to reflect technical advances during the SeaWiFS Project cycle. The present edition (Revision 1) incorporates new protocols in several areas, including expanded protocol descriptions for Case-2 waters and other improvements, as contributed by several members of the SeaWiFS Science Team.

Cliff, A.D. and Ord, J.K. 1973: Spatial autocorrelation. London: Pion:

Abstract: In 1973, Pion published A.D. Cliff and J.K. Ord’s Spatial autocorrelation, a path-breaking monograph that came to have an enormous impact on geographical data analysts. The monograph deserves the praise accorded it because it spelt out for the first time concisely, comprehensively and in detail solutions to the problem of identifying spatial association in mapped data. The monograph, based on earlier writings of the two authors a geographer and a statistician opened the door to a new era in geographical analysis. It enabled researchers to assess statistically the degree of spatial dependence in their data and, in so doing, to search for more accurate solutions to their problems, including finding additional

Quaternary soils and dust deposition in southern Nevada and California

Abstract: Eoliandustconstitutesmuchofthepedogenic material in late Pleistocene and Holocene soils of many arid regions of the world.Comparisonofthecompositionsand influx rates of modern dust with the eolian component of dated soils at 24 sites in southern Nevada and California yields informationon(1)thecompositionandinflux rate of dust in late Pleistocene and Holocene soils, (2) paleoclimate and its effects on the genesis of aridic soils, especially with regard to dustfall events, (3) the timing and relative contribution of dust from playa sources versus alluvial sources, and (4) the effects of accumulation of dust in soil horizons. The<2mmfractionsofAandBhorizons of soils formed on gravelly alluvial-fan deposits in the study area are similar to moderndustingrainsize,contentofCaCO3and salt,majoroxides,andclaymineralogy;thus, they are interpreted to consist largely of dust. The major-oxide compositions of the shallow soil horizons are nearly identical to that of the modern dust, but the compositions of progressively deeper horizons approachthatoftheparentmaterial.Theclay mineralogyofmoderndustatagivensiteis similar to that of the Av horizons of nearby Holocene soils but is commonly different from the mineralogies of deeper soil horizonsandoftheAvhorizonsofnearbyPleistocenesoils.Theseresultsareinterpretedto indicate that dust both accumulates and is transformed in Av horizons with time. Changes in soil-accumulation rates provide insights into the interplay of paleoclimate,dustsupply,andsoil-formingprocesses. Modern dust-deposition rates are more than large enough to account for middle and late Holocene soil-accumulation rates at nearly all sites. However, the early Holocene soil-accumulation rates in areas near late Pleistocene pluvial lakes are much higher than modern rates and clearly indicate a dust-deflation and -deposition event that caused rapid formation offine-grained shallow soil horizons on uppermost Pleistocene and lower Holocene deposits. We interpret late Pleistocene soil-accumulation rates to indicate that dust-deposition rates were low during this period but that increased effective moisture during the late Wisconsinan favored translocation of clay andCaCO3fromnearthesurfacetodeeper inthesoilprofile.Pre‐latePleistocenerates are very low in most areas, mainly due to a pedogenic threshold that was crossed when accumulations of silt, clay, and CaCO3 began to inhibit the downward transport of eolian material, but in part due to erosion.

Odor identification as an early marker for Alzheimer's disease: impact of lexical functioning and detection sensitivity.

Abstract: The impact of lexical functioning and detection sensitivity on the deficit of odor identification in Alzheimer's disease (AD) was studied in persons diagnosed with probable and questionable AD. Tests consisted of lexical-based odor identification, lexical-based picture identification, picture-based odor identification, and odor-detection threshold. Results suggest (1) that odor identification is poorer than picture identification in probable and questionable AD, (2) that odor identification continues to be poor even when lexical demands are eliminated, (3) that odor detection does contribute to the odor-identification deficit, but does not account for it completely, and (4) that odor identification tests have a correct classification rate of 83 – 100%. Odor identification tests can be very useful tools in diagnosing AD and should be considered an important addition to existing diagnostic test batteries.

Toward a Theory of Comparative Management Research: An Idiographic Case Study of The Best International Human Resources Management Project

Abstract: Cross-cultural international management research is complex, costly, and frequently, nonrigorous. This idiographic study documents the evolution of a multinational, multicultural, interdisciplinary research consortium that sought to remedy this lack of rigor in a project investigating international human resource management practices. We identify key learning points derived from this project and conclude with the rudiments of a midrange theory of a comparative management research methodology.

The Dark Side of Interpersonal Communication

Abstract: Contents: Part I: Amusing & Bemusing. B.H. Spitzberg, W.R. Cupach, Disentangling the Dark Side of Interpersonal Communication. Part II: Schmoozing, Choosing, and Confusing. L. Knobloch, The Dark Side of Relational Uncertainty: Obstacle or Opportunity. T. Afifi, W. Afifi, J. Caughlin, The Dark Side (and Light Side) of Avoidance and Secrets. M. Whitty, Manipulation of Self in Cyberspace. Part III: Bruising. A.L. Vangelisti, Communicating Hurt. W.R. Cupach,"You're Bugging Me!": Complaints and Criticism From a Partner. R.M. Kowalski, Teasing and Bullying. Part IV: (Mis)Using, Accusing, and Excusing. M. Tafoya, B.H. Spitzberg, The Dark Side of Infidelity: Its Nature, Scope, and Communicative Functions. S. Metts, W.R. Cupach, Responses to Relational Transgressions: Hurt, Anger, and Sometimes Forgiveness. Part V: Abusing. S. Yoshimura, The Communication of Revenge: On the Viciousness, Virtues, and Vitality of Vengeful Behavior in Interpersonal Relationships. R. Dailey, C. Lee, B. Spitzberg, Communicative Aggression: Toward a More Interactional View of Psychological Abuse. W. Morgan, S.R. Wilson, Explaining Child Abuse as a Lack of Safe Ground. N. Eckstein, Adolescent-to-Parent Abuse: Exploring the Communicative Patterns Leading to Verbal, Physical, and Emotional Abuse.

Origins of children's helpless and mastery achievement patterns in the family.

Abstract: An exploratory study examined the origins of children's motivational patterns in the family by observing 3rd-grade children (10 helpless and 11 mastery-oriented) and their mothers performing a series of solvable and insolvable problem-solving tasks. Mothers of mastery children appeared to show sensitivity and responsiveness to their children's ability perceptions and requests for help. They also appeared to support mastery behaviors in their children by increasing task-focused teaching behaviors and maintaining high-positive affect during the insolvable puzzles. Furthermore, in the face of failures, they retrained their children's low-ability attributions and performance-goal statements, while promoting mastery or taskfocused behaviors. These findings are consistent with the hypothesis that mothers of mastery children may socialize their children's achievement motivation. However, because of the small sample size and other limitations, the results should be interpreted with caution. Several directions are outlined for future research on the familial origins of helpless and mastery patterns in children.

Fashioning Australia's forests.

Abstract: Preface. Acknowledgements. Abbreviations. Patterns of Australia's Forests. Introduction. Fashioning, 1850s and 1960s. 1: Forests for home and empire. 2: Forests for industrialisation. 3: Forests for conservation and delight. Changing, 1970s and 1980s. 4: Forests for Japan. 5: Forests for work and regional development. 6: Forests for existence and experience. Contesting, from the 1970s. 7: Contesting existence, ecology and experience. 8: Contesting industries and regions. 9: Contesting politics and the state. Creating, 1990s and Beyond. 10: Forests prospects in a changing world. Appendix. Notes. Bibliography. Figures and Plates

Measurement, evaluation and reward of profit center managers: A cross-cultural field study

Abstract: This study explored differences between U.S. and Taiwanese firms in measuring, evaluating and rewarding profit center managers, a subject which has not been addressed in the research literature. Four research propositions were developed based on a review of the existing literature on the effects of differences in national culture. These propositions were used to guide a field study in four firms, two in each country, matched in terms of existence of multiple profit centers, industry, and, to some extent, size. The choice of a field research method reflected the nascent state of theory development in the areas being studied. Thus, possible statistical significance of the findings was sacrificed in favor of depth of situational understanding and opportunities to explore new theoretical possibilities. The findings were generally inconsistent with the research propositions, thus suggesting at best a weak link between the previously identified dimensions of national culture and firms' measurement, evaluation and reward practices. The only finding consistent with expectations was that as compared to U.S. firms, Taiwanese firms make less use of long-term (multi-year) incentives. However, the study did reveal seven other variables that seem to be more important than national culture in explaining differences (and similarities) between the practices of the firms in the two countries. This list includes senior managers' education and experience, the company's stage of economic development, managers' beliefs about the workings of their nation's stock market, the company's type of business, the nation's labor force mobility, the company's pattern of growth, and the use of consultants. The paper explains the effects of each of these variables on the firms' management control system practices and, consequently, provides a contribution to theory development in this area.

Phosphorylation modulates catalytic function and regulation in the cAMP-dependent protein kinase.

Abstract: Site-directed mutagenesis was used to remove a critical phosphorylation site, Thr-197, near the active site of the catalytic subunit of cAMP-dependent protein kinase. This residue is present in a number of protein kinases, and its phosphorylation largely influences catalytic activity. We changed Thr-197 to aspartic acid and alanine and measured the effects of these substitutions on the kinetic mechanism and inhibitor affinities. The mutants were expressed as the free catalytic subunit and as soluble fusion proteins of glutathione-S-transferase. The values for KATP and Kpeptide for all three mutants are raised by approximately 2 orders of magnitude relative to the wild-type enzyme. Viscosometric measurements indicate that elevations in Kpeptide are the result of reduced rates for phosphoryl transfer and not reduced substrate affinities. This implies that the loop that contains the phosphothreonine, the activation loop, does not reduce access to the substrate site as proposed for the inactive forms of cdk2 kinase [DeBont, H. L., et al. (1993) Nature 363, 595-602] and MAP kinase [Zhang, F., et al. (1994) Nature 367, 704-711]. The mutants associate slowly with the wild-type regulatory subunit, although the cAMP-free wild-type regulatory subunit inhibits the mutants stoichiometrically. A mutant regulatory subunit that binds cAMP poorly and rapidly inhibits the wild-type catalytic subunit does not inhibit the mutant proteins. These data suggest that the phosphothreonine region serves as a docking surface for the regulatory subunit in the holoenzyme complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Production of complex syntax in normal ageing and alzheimer's disease

Abstract: Word-finding difficulties are among the earliest symptoms of Alzheimer's disease (AD), but most AD patients retain the ability to produce well-formed sentences until the late stages of their disease. This dissociation has been used to argue for a modular distinction between grammar and the lexicon. In this paper, we offer an alternative view. First, we show that grammatical production is impaired in AD patients when grammar is assessed under highly constrained conditions in a film description task. Furthermore, these grammatical deficits are comparable in some respects to the patterns of lexical impairment observed in this and other studies of AD; specifically, patients do not produce frank lexical or grammatical errors, but they do find it difficult to access the “best fit” between meaning and form. We propose that differences in the onset time for lexical and grammatical symptoms in AD are due not to a disconnection between modules, but to fundamental differences in the automaticity and/or acce...

Fashioning Australia's Forests

Abstract: Preface. Acknowledgements. Abbreviations. Patterns of Australia's Forests. Introduction. Fashioning, 1850s and 1960s. 1: Forests for home and empire. 2: Forests for industrialisation. 3: Forests for conservation and delight. Changing, 1970s and 1980s. 4: Forests for Japan. 5: Forests for work and regional development. 6: Forests for existence and experience. Contesting, from the 1970s. 7: Contesting existence, ecology and experience. 8: Contesting industries and regions. 9: Contesting politics and the state. Creating, 1990s and Beyond. 10: Forests prospects in a changing world. Appendix. Notes. Bibliography. Figures and Plates

Coping with the green‐eyed monster: Conceptualizing and measuring communicative responses to romantic jealousy

Abstract: Communicative responses to jealousy perform critical functions in interpersonal relationships: They can reduce uncertainty, help maintain or repair relationships, and aid the jealous person in saving face and restoring self‐esteem. The three studies reported herein concentrate on conceptualizing and measuring communicative responses to jealousy that are relevant to these functions. Study 1 is a descriptive, qualitative analysis of respondents' communicative responses to jealousy. Twelve superordinate categories and 67 tactics were found. Studies 2 and 3 focus on finding reliable and valid measures representing the various responses found in Study 1. Measures for six types of interactive responses (integrative communication, distributive communication, active distancing, general avoidance/denial, expression of negative affect, and violent communication/threats) and five types of general responses (surveillance/restriction, compensatory restoration, manipulation attempts, rival contact, and violent behavior...

Chaos and evolution.

Abstract: There is growing interest in applying nonlinear methods to evolutionary biology. With good reason: the living world is full of nonlinearities, responsible for steady states, regular oscillations, and chaos in biological systems. Evolutionists may find nonlinear dynamics important in studying short-term dynamics of changes in genotype frequency, and in understanding selection and its constraints. More speculatively, dynamical systems theory may be important because nonlinear fluctuations in some traits may sometimes be favored by selection, and because some long-run patterns of evolutionary change could be described using these methods.

Cardiovascular Risk Factors among Third Grade Children in Four Regions of the United States: The CATCH Study

Abstract: Data on cardiovascular risk factors (body mass index, triceps and subscapular skinfolds, blood pressure, serum total cholesterol, high density lipoprotein (HDL) cholesterol, and apolipoprotein B) were collected as part of the baseline examination (fall 1991) of the Child and Adolescent Trial for Cardiovascular Health, a multicenter school-based intervention study for promoting healthful behaviors. A total of 5,106 third grade children (mean age, 8.76 years) in four states (California, Louisiana, Minnesota, and Texas) were examined. After excluding 194 children of other or unknown origin, the study population consisted of 3,530 Anglo-American children, 674 African-American children, and 708 Latino children. African-American children were the tallest by 1-3 cm (p < 0.0001), while Latino children had the largest body mass index (p < 0.05). Blood pressure levels were similar for boys and girls and among the three races, but systolic levels were 2 mmHg higher in Texas than at the other sites. Serum total cholesterol levels were 5 mg/dl higher in girls than in boys (p < 0.05), while HDL cholesterol levels were 2 mg/dl higher in boys (p < 0.05). HDL cholesterol levels were highest in African-Americans (55.5 mg/dl) compared with Anglo-Americans (50.7 mg/dl) and Latinos (51.3 mg/dl) (p < 0.0001).