bluuebunny/crossref_metadata_2025 huggingface dataset:
Fractal dynamics in physiology: Alterations with disease and aging
Authors: Goldberger Ary L. , Amaral Luis A. N. , Hausdorff Jeffrey M. , Ivanov Plamen Ch. , Peng C.-K. , Stanley H. Eugene
Published: December 2002

According to classical concepts of physiologic control, healthy systems are self-regulated to reduce variability and maintain physiologic constancy. Contrary to the predictions of homeostasis, however, the output of a wide variety of systems, such as the normal human heartbeat, fluctuates in a complex manner, even under resting conditions. Scaling techniques adapted from statistical physics reveal the presence of long-range, power-law correlations, as part of multifractal cascades operating over a wide range of time scales. These scaling properties suggest that the nonlinear regulatory systems are operating far from equilibrium, and that maintaining constancy is not the goal of physiologic control. In contrast, for subjects at high risk of sudden death (including those with heart failure), fractal organization, along with certain nonlinear interactions, breaks down. Application of fractal analysis may provide new approaches to assessing cardiac risk and forecasting sudden cardiac death, as well as to monitoring the aging process. Similar approaches show promise in assessing other regulatory systems, such as human gait control in health and disease. Elucidating the fractal and nonlinear mechanisms involved in physiologic control and complex signaling networks is emerging as a major challenge in the postgenomic era.
Positive feedback, memory, and the predictability of earthquakes
Authors: Sammis C. G. , Sornette D.
Published: December 2002

We review the “critical point” concept for large earthquakes and enlarge it in the framework of so-called “finite-time singularities.” The singular behavior associated with accelerated seismic release is shown to result from a positive feedback of the seismic activity on its release rate. The most important mechanisms for such positive feedback are presented. We solve analytically a simple model of geometrical positive feedback in which the stress shadow cast by the last large earthquake is progressively fragmented by the increasing tectonic stress.
Wavelet analysis of shoreline change on the Outer Banks of North Carolina: An example of complexity in the marine sciences
Authors: Tebbens Sarah F. , Burroughs Stephen M. , Nelson Eric E.
Published: December 2002

The horizontal, shore-perpendicular change in shoreline position along the Outer Banks of North Carolina is found to be a self-affine signal. We measure shoreline change by determining the horizontal change in position of the 0.8-m contour sampled from shore-perpendicular profiles spaced at 20-m intervals along the coast. The profiles are obtained from two light detection and ranging surveys performed in September 1997 and September 1998. For six selected sections of coast, wavelet analysis of the shoreline change signal indicates the signal is self-affine with a scaling exponent that varies from 1.2 to 2.1. This self-affine behavior indicates that the shoreline change signal is nonstationary with long-range persistence. A stochastic diffusion model of sediment transport replicates the observed self-affine behavior observed south of Cape Hatteras (scaling exponent between 1.2 and 1.6) whereas a random walk model replicates the signal observed north of Cape Hatteras (scaling exponent ≈2.0). Because of the finite nature of the data set, there are limits in space and time to the power law behavior of the system. Characteristics of such systems can be described by upper-truncated power laws, which yield the upper limits of power law behavior. Applying an upper-truncated power law to the data for one section of coast, we find an upper limit of 7 km for the maximum continuous alongshore distance eroding or accreting. For the same section of coast, we find upper limits of 25 m for the maximum shore-perpendicular erosion and 11 m for the maximum shore-perpendicular accretion during the study period.
Scaling phenomena in the Internet: Critically examining criticality
Authors: Willinger Walter , Govindan Ramesh , Jamin Sugih , Paxson Vern , Shenker Scott
Published: December 2002

Recent Internet measurements have found pervasive evidence of some surprising scaling properties. The two we focus on in this paper are self-similar scaling in the burst patterns of Internet traffic and, in some contexts, scale-free structure in the network's interconnection topology. These findings have led to a number of proposed models or “explanations” of such “emergent” phenomena. Many of these explanations invoke concepts such as fractals, chaos, or self-organized criticality, mainly because these concepts are closely associated with scale invariance and power laws. We examine these criticality-based explanations of self-similar scaling behavior—of both traffic flows through the Internet and the Internet's topology—to see whether they indeed explain the observed phenomena. To do so, we bring to bear a simple validation framework that aims at testing whether a proposed model is merely evocative, in that it can reproduce the phenomenon of interest but does not necessarily capture and incorporate the true underlying cause, or indeed explanatory, in that it also captures the causal mechanisms (why and how, in addition to what). We argue that the framework can provide a basis for developing a useful, consistent, and verifiable theory of large networks such as the Internet. Applying the framework, we find that, whereas the proposed criticality-based models are able to produce the observed “emergent” phenomena, they unfortunately fail as sound explanations of why such scaling behavior arises in the Internet.
Agent-based modeling as organizational and public policy simulators
Authors: Lempert Robert
Published: December 2002

Agent-based models are an increasingly powerful tool for simulating social systems because they can represent important phenomenon difficult to capture in other mathematical formalisms. But, agent-based models have provided only limited support for policy-making because their distinctive abilities are often most useful in situations where the future is unpredictable. In such situations, the traditional analytic methods for applying simulation models to support decision-making are least effective. Fortunately, new analytic approaches for decision-making under conditions of deep uncertainty—emphasizing large ensembles of model-created scenarios and adaptive policies evaluated with the criteria of robustness, rather than with optimality or efficiency—can unleash the full potential of agent-based policy simulators.
Short-memory traders and their impact on group learning in financial markets
Authors: LeBaron Blake
Published: December 2002

This article highlights several issues from simulating agent-based financial markets. These all center around the issue of learning in a multiagent setting, and specifically the question of whether the trading behavior of short-memory agents could interfere with the learning process of the market as whole. It is shown in a simple example that short-memory traders persist in generating excess volatility and other features common to actual markets. Problems related to short-memory trader behavior can be eliminated by using several different methods. These are discussed along with their relevance to agent-based models in general.
Agent-based modeling: A revolution?
Authors: Bankes Steven C.
Published: December 2002

A clear consensus among the papers in this Colloquium is that agent-based modeling is a revolutionary development for social science. However, the reasons to expect this revolution lie more in the potential seen in this tool than through realized results. In order for the anticipated revolution to occur, a series of challenges must be met. This paper surveys the challenges suggested by the papers of this session.
Modeling the stylized facts in finance through simple nonlinear adaptive systems
Authors: Hommes Cars H.
Published: December 2002

Recent work on adaptive systems for modeling financial markets is discussed. Financial markets are viewed as evolutionary systems between different, competing trading strategies. Agents are boundedly rational in the sense that they tend to follow strategies that have performed well, according to realized profits or accumulated wealth, in the recent past. Simple technical trading rules may survive evolutionary competition in a heterogeneous world where prices and beliefs co-evolve over time. Evolutionary models can explain important stylized facts, such as fat tails, clustered volatility, and long memory, of real financial series.
Invariance and universality in social agent-based simulations
Authors: Cioffi-Revilla Claudio
Published: December 2002

Agent-based simulation models have a promising future in the social sciences, from political science to anthropology, economics, and sociology. To realize their full scientific potential, however, these models must address a set of key problems, such as the number of interacting agents and their geometry, network topology, time calibration, phenomenological calibration, structural stability, power laws, and other substantive and methodological issues. This paper discusses and highlights these problems and outlines some solutions.
Trust, cooperation, and market formation in the U.S. and Japan
Authors: Macy Michael W. , Sato Yoshimichi
Published: December 2002

Compared with the U.S., Japan is believed to have a collectivist culture that nurtures high trust. Results from laboratory and survey research, however, show that Americans are more likely to trust strangers than are Japanese. Why would trust be lower in a collectivist culture? We use an agent-based computational model to explore the evolutionary origin of this puzzling empirical finding. Computer simulations suggest that higher social mobility in the U.S. may be the explanation. With low mobility, agents rarely encounter strangers and thus remain highly parochial, trusting only their neighbors and avoiding open-market transactions with outsiders. With moderate mobility, agents learn to read telltale signs of character so that they can take advantage of better opportunities outside the neighborhood. However, if mobility is too great, there is too little trustworthiness to make the effort to discriminate worthwhile. This finding suggests that higher mobility in the U.S. may explain why Americans are more trusting than Japanese, but if mobility becomes too high, the self-reinforcing high-trust equilibrium could collapse.
Modeling civil violence: An agent-based computational approach
Authors: Epstein Joshua M.
Published: December 2002

This article presents an agent-based computational model of civil violence. Two variants of the civil violence model are presented. In the first a central authority seeks to suppress decentralized rebellion. In the second a central authority seeks to suppress communal violence between two warring ethnic groups.
Growing older: The adult metabolic clinic
Authors: Lee P. J.
Published: December 2002

Improvements in screening programmes, diagnostic tests and therapeutic interventions have all led to increasing numbers of children with inherited metabolic diseases surviving through childhood into adolescence and adulthood. These individuals are often able to integrate into society, but many have complex, multisystem problems that require ongoing care. Understanding of the long‐term outcome of these disorders is scanty. Awareness of these conditions within the adult medical community is sadly limited and much of the good work of the paediatricians potentially could go to waste. This is often prevented by paediatricians remaining involved in patient care into the third decade and beyond. Appropriate resources to deal with the transition from the children's services to the adult sector are necessary, and appropriately trained medical and dietetic personnel are required to run these services. An adult inborn errors service needs to have close links with a feeding paediatric unit, as well as to integrate with other adult medical and surgical specialties, and to be supported by metabolic biochemical and molecular laboratories. This paper discusses the issues around this growing problem based upon experience gained working within a single centre dedicated to the care of adults and adolescents with inborn errors of metabolism.
Human gene mutation in pathology and evolution
Authors: Cooper D. N.
Published: December 2002

Mutations in human gene pathology and evolution represent two sides of the same coin in that the same mechanisms that have frequently been implicated in disease‐associated mutagenesis appear also to have been involved in potentiating evolutionary change. Indeed, the mutational spectra of germline mutations responsible for inherited disease, somatic mutations underlying tumorigenesis, polymorphisms (either neutral or functionally significant) and differences between orthologous gene sequences exhibit remarkable similarities, implying that they may have causal mechanisms in common. Since these different categories of mutation share multiple unifying characteristics, they should no longer be viewed as distinct entities but rather as portions of a continuum of genetic change that links population genetics and molecular medicine with molecular evolution.
Tyrosinaemia type I and apoptosis of hepatocytes and renal tubular cells
Authors: Endo F. , Sun M.‐S.
Published: December 2002

Hereditary tyrosinaemia type I (HT I) (McKusick 276700) is caused by a deficiency of fumarylacetoacetate hydrolase (FAH) activity, the last enzyme in the tyrosine catabolic pathway. Homozygous disruption of the gene encoding FAH in mice (Fah) causes neonatal lethality (i.e. lethal Albino deletion c14CoS mice), which limits the use of this animal as a model for HT I. We developed a new mouse model that carries two genetic defects, Fah and 4‐hydroxyphenyl‐pyruvate dioxygenase (Hpd). The double mutant Fah−/−Hpd−/− mice grew normally without evidence of liver and renal disease, showing a phenotype similar to Hpd−/− mice. Complete blockage of the tyrosine catabolic pathway at the, step of HPD prevents development of clinical phenotypes. Administration of homogentisate resulted in rapid apoptosis of hepatocytes and renal tubular epithelial cells, a central feature of visceral injury in patients with HT I. Simultaneously, renal tubular function was impaired, resulting in Fanconi syndrome. Apoptosis of hepatocyte and renal tubular cells is prevented by the caspase inhibitors YVAD or DEVD. However, these inhibitors do not prevent the release of cytochrome c or the development of renal tubular dysfunction. Apoptosis of hepatocytes and of renal tubular epithelial cells are characteristic features of this disease and the apoptotic signal in this disease seems to be initiated by fumarylacetoacetate.
Does hereditary metabolic disease modulate senescence and ageing?
Authors: Scriver C. R.
Published: December 2002

Hereditary metabolic diseases in the context of evolutionary biology elicit interesting questions about ageing and senescence: Will persons successfully treated for inborn errors of metabolism, age and die prematurely because of compromised longevity? Because some unhealthy longevity has its origins in germline and somatic mutational processes, and in an inability to withstand metabolic stress, are there lessons to be learned about senescence from hereditary metabolic disease? Why are ageing, senescence and death necessary forHomo sapiensand how do they happen?

These questions form the theme upon which several variations are played during the course of this essay. The theory of the disposable soma recognizes genomic and environmental events, well‐seasoned by Chance, as determinants of ageing and senescence. Together, they cause the somatic damage that results in death. Genomics will reveal genes involved in longevity, both healthy and unhealthy. There will be schedules of gene expression behind our life‐history traits. As in the field of hereditary metabolic disease, analogous genetic enquiries about ageing can be formulated. For example, how will heterozygotes age? Will association studies in centenarians reveal ‘longevity genes’? Will disparate longevity in sib pairs reveal genetic factors? If there are ‘ageing’ mutations, of what types and with what effects? Will these initiatives lead to healthier longevity? A deeper question yet remains: why has human biology invested so greatly in grandparenthood?
Concepts of Social Justice in Community Psychology: Toward a Social Ecological Epistemology
Authors: Fondacaro Mark R. , Weinberg Darin
Published: December 2002

In this paper we address the pervasive tendency in community psychology to treat values like social justice only as general objectives rather than contested theoretical concepts possessing identifiable empirical content. First we discuss how distinctive concepts of social justice have figured in three major intellectual traditions within community psychology: (1) the prevention and health promotion tradition, (2) the empowerment tradition, and most recently, (3) the critical tradition. We point out the epistemological gains and limitations of these respective concepts and argue for greater sensitivity to the context dependency of normative concepts like social justice. More specifically, we point to a pressing need in community psychology for an epistemology that: (1) subsumes both descriptive and evaluative concepts, and (2) acknowledges its own embeddedness in history and culture without thereby reducing all knowledge claims to the status of ideology. Finally, we describe and demonstrate the promise of what we are calling a social ecological epistemology for fulfilling this need.
Reconstitution of Novel Mitochondrial Uncoupling Proteins UCP2 and UCP3
Authors: Žáčkova Markéta , Ježek Petr
Published: December 2002

Reconstitution of novel mitochondrial uncoupling proteins, human UCP2 and UCP3, expressed in yeast, was performed to characterize fatty acid (FA)-induced H+ efflux in the resulted proteoliposomes. We now demonstrate for the first time that representatives of physiologically abundant long chain FAs, saturated or unsaturated, activate H+ translocation in UCP2- and UCP3-proteoliposomes. Efficiency of lauric, palmitic or linoleic acid was roughly the same, but oleic acid induced faster H+ uniport. We have confirmed that ATP and GTP inhibit such FA-induced H+ uniport mediated by UCP2 and UCP3. Coenzyme Q10 did not further significantly activate the observed H+ efflux. In conclusion, careful instant reconstitution yields intact functional recombinant proteins, UCP2 and UCP3, the activity of which is comparable with UCP1.
Thyroid Hormones and Mitochondria
Authors: Goglia Fernando , Silvestri Elena , Lanni Antonia
Published: December 2002

Because of their central role in the regulation of energy-transduction, mitochondria, the major site of oxidative processes within the cell, are considered a likely subcellular target for the action that thyroid hormones exert on energy metabolism. However, the mechanism underlying the regulation of basal metabolic rate (BMR) by thyroid hormones still remains unclear. It has been suggested that these hormones might uncouple substrate oxidation from ATP synthesis, but there are no clear-cut data to support this idea. Two iodothyronines have been identified as effectors of the actions of thyroid hormones on energy metabolism: 3',3,5-triiodo-L-thyronine (T3) and 3,5-diiodo-L-thyronine (T2). Both have significant effects on BMR, but their mechanisms of action are not identical. T3 acts on the nucleus to influence the expression of genes involved in the regulation of cellular metabolism and mitochondria function; 3,5-T2, on the other hand, acts by directly influencing the mitochondrial energy-transduction apparatus. A molecular determinant of the effects of T3 could be uncoupling protein-3 (UCP-3), while the cytochrome-c oxidase complex is a possible target for 3,5-T2. In conclusion, it is likely that iodothyronines regulate energy metabolism by both short-term and long-term mechanisms, and that they act in more than one way in affecting mitochondrial functions.
Molecular Investigations on tRNAs Involved in Human Mitochondrial Disorders
Authors: Florentz Catherine
Published: December 2002

Over the last decade, human neurodegenerative disorders which correlate with point mutations in mitochondrial tRNA genes became more and more numerous. Both the number of mutations (more than 70) and the variety of phenotypes (cardiopathies, myopathies, encephalopathies as well as diabetes, deafness or others) render the understanding of the genotype/phenotype relationships very complex. Here we first summarize the efforts undertaken to decipher the initial impact of various mutations on the structure/function relationships of tRNAs. This includes several lines of research, namely (i) investigation of human mitochrondrial tRNA structures, (ii) comparison of disease-related and polymorphic mutations at a theoretical level, and (iii) experimental investigations of affected tRNAs in the frame of mitochondrial protein synthesis. A new approach aimed at searching for long-range effects of mitochondrial tRNA mutations on a broader global mitochondrial level will also be presented. Initial results obtained by comparative mitochondrial proteomics turn out to be very promising for deciphering unexpected molecular partners involved in the pathological status of the mitochondria.
Traumatic stress responses in earthquake survivors in Turkey
Authors: Başoǧlu Metin , Şalcioǧlu Ebru , Livanou Maria
Published: December 2002

This study examined the rates of posttraumatic stress disorder (PTSD) and depression and associated risk factors in earthquake survivors in Turkey. A group of 1,000 people from 3 camps and 2 prefabricated housing sites in the epicenter region was assessed using the Screening Instrument for Traumatic Stress in Earthquake Survivors. The estimated rates of PTSD and major depression were 43 and 31%, respectively. Traumatic stress symptoms related to more intense fear during the earthquake, female gender, having been trapped under rubble, death of a family member, past psychiatric illness, having participated in rescue work, and lower education. Avoidance of trauma reminders was the most common symptom and needs special attention in survivor care because of it mental health, social, and economic implications.
Emotional adjustment in survivors of sexual assault living with HIV‐AIDS
Authors: Kalichman Seth C. , Sikkema Kathleen J. , DiFonzo Kari , Luke Webster , Austin James
Published: December 2002

This study examined history of sexual assault in 357 men and women living with HIV‐AIDS. Participants completed measures of demographic characteristics, sexual assault history emotional distress and psychiatric symptoms, substance use, and sexual behaviors. Results showed that 68% of women and 35% of men living with HIV‐AIDS reported a history of sexual assault since age 15. History of sexual assault was related to history of substance use and mental health treatment. Sexual assault survivors reported greater anxiety, depression, and symptoms of borderline personality and were significantly more likely to report recent unprotected intercourse than persons who had not been sexually assaulted. Results suggest tailoring secondary prevention interventions to meet the needs of HIV‐positive survivors of sexual assault.
Traumatic stress symptoms among women with recently diagnosed primary breast cancer
Authors: Koopman Cheryl , Butler Lisa D. , Classen Catherine , Giese‐Davis Janine , Morrow Gary R. , Westendorf Joan , Banerjee Tarit , Spiegel David
Published: December 2002

This study examined the concurrent and longitudinal relationships between traumatic stress symptoms and demographic, medical, and psychosocial variables among women recently diagnosed with primary breast cancer. Participants were 117 women drawn from a parent study for women recently diagnosed with primary breast cancer. At baseline, the Impact of Event Scale (IES) total score was related to intensity of postsurgical treatment and lower emotional self‐efficacy. At the 6‐month follow‐up, the IES total score was significantly related to younger age, to the increased impact of the illness on life, and to the baseline IES total score assessment. These results suggest that it is important to intervene for traumatic stress symptoms soon after the diagnosis of breast cancer. Furthermore, these results suggest women at greatest risk are those who are younger, who receive postsurgical cancer treatment, who are low in emotional self‐efficacy and whose lives are most affected by having cancer.
Beyond Bruises and Broken Bones: The Joint Effects of Stress and Injuries on Battered Women's Health
Authors: Sutherland Cheryl A. , Bybee Deborah I. , Sullivan Cris M.
Published: December 2002

We investigated the joint mediating effects of injuries and stress on the relationship between abuse and women's health. A community sample of 397 women, half of whom had been assaulted by an intimate partner within the prior 6 months, was interviewed about their experience of intimate partner violence, injuries, stress, income, depression, and physical health problems. Structural equation modeling techniques confirmed the complex model of hypothesized indirect effects of abuse on women's physical health problems through injuries, stress, and depression. Stress accounted for 80% of the indirect effect of abuse on women's physical health. Its direct effect on physical health was somewhat larger than its indirect effect through depression, but both processes played a key role in determining the effect of abuse on women's physical health problems. Furthermore, abuse was a stronger predictor of women's stress than was poverty. Implication and future research are discussed.
Gender, Economic Context, Perceptions of Safety, and Quality of Life: A Case Study of Lowell, Massachusetts (U.S.A.), 1982–96
Authors: Mulvey Anne
Published: December 2002

From 1982 through 1996, 840 structured interviews about urban quality of life (QOL) were conducted with residents of Lowell, Massachusetts, by graduate students in a seminar about the city. Perceptions of safety and general QOL were analyzed by social status (gender) and social contexts (economic and historic) using multivariate and univariate ANOVAS. Main effects were obtained for gender, area income, and time. Subsequent analyses revealed that men felt safer than did women at night in neighborhoods and downtown, and that residents of lower income areas perceived both neighborhood QOL and safety more negatively than residents of higher income areas did. Small effects were found for downtown safety by area income in the opposite direction. Differences over time for downtown safety and city QOL (but not for neighborhood) suggest that the early and mid‐1980s were viewed somewhat more favorably than the 1990s, with some improvement in the most recent period. Results suggest that economic context and time were related to perceived safety and QOL, though in different ways, whereas gender was related to perceived safety but not to QOL. Respondents' comments and community psychology principles are used to elaborate on and suggest interpretations for quantitative results.
Do Internet‐Based Support Interventions Change Perceptions of Social Support?: An Experimental Trial of Approaches for Supporting Diabetes Self‐Management
Authors: Barrera Manuel , Glasgow Russell E. , McKay H. Garth , Boles Shawn M. , Feil Edward G.
Published: December 2002

Internet‐based support groups are a rapidly growing segment of mutual aid programs for individuals with chronic illnesses and other challenges. Previous studies have informed us about the content of online exchanges between support group members, but we know little about the ability of these interventions to change participants' perceptions of support. A randomized trial of 160 adult Type 2 diabetes patients provided novice Internet users with computers and Internet access to 1 of 4 conditions: (a) diabetes information only, (b) a personal self‐management coach, (c) a social support intervention, or (d) a personal self‐management coach and the support intervention. After 3 months, individuals in the 2 support conditions reported significant increases in support on a diabetes‐specific support measure and a general support scale. Participants' age was significantly related to change in social support, but intervention effects were still significant after accounting for this relationship. This report is a critical first step in evaluating the long‐term effects of Internet‐based support for diabetes self‐management. The discussion identifies directions for future research.
The Adoption of Innovation in Collective Action Organizations
Authors: Salem Deborah A. , Foster-Fishman Pennie G. , Goodkind Jessica R.
Published: December 2002

This study used a quantitative/qualitative methodology to explore how collective action organizations (CAOs) remain open to organizational change and innovation. It examined the adoption of inclusion—a recent innovation in the field of disabilities—by local chapters of The Arc Michigan (a disabilities CAO). We found considerable variability in the adoption of inclusion by local Arc chapters. This variability was significantly related to the ecology surrounding these chapters. Local Arc chapters that had adopted an inclusion philosophy had significantly different internal and external environments from those that had not adopted inclusion. Our qualitative findings make it clear, however, that innovative Arc chapters were not the passive recipients of these internal and external influences. These chapters were proactive players in defining and shaping the nature of their internal and external environments. Strategies that were related to a chapter's ability to remain open to innovation included (a) a change orientation, (b) a conscious philosophy or vision, (c) a proactive strategy for achieving chapter goals and overcoming barriers to change, (d) the creation of a supportive organizational network, and (e) avoidance of resource dependencies that required them to engage in activities that were inconsistent with the innovation. These findings provide a framework by which CAOs can maintain an openness to innovation and remain on the forefront of social change.
Women's Knowledge of Prenatal Ultrasound and Informed Choice
Authors: Kohut Ruth J. , Dewey Deborah , Love Edgar J.
Published: December 2002

This study evaluated women's understanding of prenatal ultrasound in terms of meeting the requirements for informed choice. A cross‐sectional survey was conducted to evaluate (1) how information is provided, (2) women's perceived value of the information received and, (3) their understanding of ultrasound in relation to the principles of informed choice. Women (n = 113) completed a questionnaire prior to their 18‐week ultrasound. Fifty‐five percent stated they received no information from their care provider. Only 31.9% considered health care providers as a “very helpful” source of information. Yet, 69.0% stated their care provider gave them information that facilitated their understanding. Gaps were identified in women's understanding of ultrasound. Specifically, 46.0% did not view ultrasound as a screen for anomalies; some were uncertain about the safety (18.6%), diagnostic capabilities (26.5%), and limitations of testing (37.2%). These results suggest that women's understanding of ultrasound does not meet the requirements of informed choice.
The Colored, Eco‐Genetic Relationship Map (CEGRM): A Conceptual Approach and Tool for Genetic Counseling Research
Authors: Kenen Regina , Peters June
Published: December 2002

The Colored Ecological and Genetic Relational Map (CEGRM) [pronounced see‐gram] is a conceptual approach and tool for presenting information about family and nonkin relationships and stories about inherited diseases in a simple, understandable form. It combines information that can be derived from pedigrees, genograms, ecomaps, and social network analysis in a single, or series of, pictorial maps based on colors and shapes. The CEGRM is based on a social systems perspective, particularly emphasizing social exchange and resource theories. The CEGRM should be particularly useful in genetic counseling research with members of suspected cancer‐risk families or families with other late‐onset inherited diseases. A genetic counseling client comes with a social history and context as well as a genetic one. Client decision‐making in terms of reproductive plans, therapeutic intervention, lifestyle behavior and sharing or withholding of genetic information frequently becomes enmeshed with preexisting psycho‐social relationships among biological kin, affinal kin (in‐laws) and fictive kin (friends who act as family). The CEGRM makes it easier to compare different types of social interactions between the client and his/her significant others and among family members on the same dimensions.
Grounded Theory in Genetic Counseling Research
Authors: McAllister Marion
Published: December 2002

The practice of genetic counseling is in need of evidence‐based theoretical frameworks. Although strategies used in genetic counseling are increasingly evidence‐based, the field of genetic counseling does not have a generally accepted theoretical basis for development of therapeutic interventions. We know very little about (1) what actually happens in genetic counseling and (2) the impact it has on clients and their families. A number of researchers have used a variety of approaches in an attempt to introduce some theoretical basis for genetic counseling research and practice. Other workers have used experience in their clinical practice to write theoretically about the kinds of processes that might be going on in and around genetic counseling. However, there are few studies to date, which have attempted to build theory modeling the psychosocial processes that take place in and around the genetic counseling clinic using empirical data. This paper describes a methodology (grounded theory) that is designed specifically to build theory about psychosocial processes from a strong evidence base, and explains how it can contribute to the development of practice in genetic counseling.
Genetic Counseling and Screening Issues in Familial Dilated Cardiomyopathy
Authors: Hanson Emily L. , Hershberger Ray E.
Published: December 2002

Idiopathic dilated cardiomyopathy (IDC), a treatable condition characterized by left ventricular dilatation and systolic dysfunction of unknown cause, has only recently been recognized to have genetic etiologies. Although familial dilated cardiomyopathy (FDC) was thought to be infrequent, it is now believed that 30‐50% of cases of IDC may be familial. Echocardiographic and electrocardiographic (ECG) screening of first‐degree relatives of individuals with IDC and FDC is indicated because detection and treatment are possible prior to the onset of advanced, symptomatic disease. However, such screening often creates uncertainty and anxiety surrounding the significance of the results. Furthermore, FDC demonstrates incomplete penetrance, variable expression, and significant locus and allelic heterogeneity, making genetic counseling complex. The provision of genetic counseling for IDC and FDC will require collaboration between cardiologists and genetics professionals, and may also improve the recognition of FDC, the availability of support services, and overall outcomes for patients and families.
The Perceptions of Lutheran Pastors Toward Prenatal Genetic Counseling and Pastoral Care
Authors: Stuck Jamalynne , Faine John , Boldt Ann
Published: December 2002

The purpose of this study is to explore a theological perspective toward genetic counseling. A survey was sent to 207 ministers within the Evangelical Lutheran Church of America (ELCA), to determine their perspectives toward four different scenarios in a prenatal genetic counseling setting. The four different scenarios included situations involving Huntington disease, Down syndrome, trisomy 18, and anencephaly. Nearly all ELCA Lutheran pastors perceived genetic counseling as beneficial and useful and wanted to be involved in the decision‐making process for whether or not to terminate the pregnancy. Their views toward termination of pregnancy varied depending on the severity of the genetic abnormality. Severity in this study was based upon life compatibility. As the severity of the genetic abnormality increased, the percentage of Lutheran pastors who viewed termination as an option increased from 23% (Down syndrome) to 62% (anencephaly). A better understanding of how spiritual leaders view genetic counseling would provide an insight into how genetics and religious beliefs together play a significant role in shaping the decisions of those faced with abnormal pregnancies.
What might we learn from climate forecasts?
Authors: Smith Leonard A.
Published: December 2002

Most climate models are large dynamical systems involving a million (or more) variables on big computers. Given that they are nonlinear and not perfect, what can we expect to learn from them about the earth's climate? How can we determine which aspects of their output might be useful and which are noise? And how should we distribute resources between making them “better,” estimating variables of true social and economic interest, and quantifying how good they are at the moment? Just as “chaos” prevents accurate weather forecasts, so model error precludes accurate forecasts of the distributions that define climate, yielding uncertainty of the second kind. Can we estimate the uncertainty in our uncertainty estimates? These questions are discussed. Ultimately, all uncertainty is quantified within a given modeling paradigm; our forecasts need never reflect the uncertainty in a physical system.
“Waves” vs. “particles” in the atmosphere's phase space: A pathway to long-range forecasting?
Authors: Ghil Michael , Robertson Andrew W.
Published: December 2002

Thirty years ago, E. N. Lorenz provided some approximate limits to atmospheric predictability. The details—in space and time—of atmospheric flow fields are lost after about 10 days. Certain gross flow features recur, however, after times of the order of 10–50 days, giving hope for their prediction. Over the last two decades, numerous attempts have been made to predict these recurrent features. The attempts have involved, on the one hand, systematic improvements in numerical weather prediction by increasing the spatial resolution and physical faithfulness in the detailed models used for this prediction. On the other hand, theoretical attempts motivated by the same goal have involved the study of the large-scale atmospheric motions' phase space and the inhomogeneities therein. These “coarse-graining” studies have addressed observed as well as simulated atmospheric data sets. Two distinct approaches have been used in these studies: the episodic or intermittent and the oscillatory or periodic. The intermittency approach describes multiple-flow (or weather) regimes, their persistence and recurrence, and the Markov chain of transitions among them. The periodicity approach studies intraseasonal oscillations, with periods of 15–70 days, and their predictability. We review these two approaches, “particles” vs. “waves,” in the quantum physics analogy alluded to in the title of this article, discuss their complementarity, and outline unsolved problems.
Self-organization, the cascade model, and natural hazards
Authors: Turcotte Donald L. , Malamud Bruce D. , Guzzetti Fausto , Reichenbach Paola
Published: December 2002

We consider the frequency-size statistics of two natural hazards, forest fires and landslides. Both appear to satisfy power-law (fractal) distributions to a good approximation under a wide variety of conditions. Two simple cellular-automata models have been proposed as analogs for this observed behavior, the forest fire model for forest fires and the sand pile model for landslides. The behavior of these models can be understood in terms of a self-similar inverse cascade. For the forest fire model the cascade consists of the coalescence of clusters of trees; for the sand pile model the cascade consists of the coalescence of metastable regions.
Complexity and robustness
Authors: Carlson J. M. , Doyle John
Published: December 2002

Highly optimized tolerance (HOT) was recently introduced as a conceptual framework to study fundamental aspects of complexity. HOT is motivated primarily by systems from biology and engineering and emphasizes, (i) highly structured, nongeneric, self-dissimilar internal configurations, and (ii) robust yet fragile external behavior. HOT claims these are the most important features of complexity and not accidents of evolution or artifices of engineering design but are inevitably intertwined and mutually reinforcing. In the spirit of this collection, our paper contrasts HOT with alternative perspectives on complexity, drawing on real-world examples and also model systems, particularly those from self-organized criticality.
Random graph models of social networks
Authors: Newman M. E. J. , Watts D. J. , Strogatz S. H.
Published: December 2002

We describe some new exactly solvable models of the structure of social networks, based on random graphs with arbitrary degree distributions. We give models both for simple unipartite networks, such as acquaintance networks, and bipartite networks, such as affiliation networks. We compare the predictions of our models to data for a number of real-world social networks and find that in some cases, the models are in remarkable agreement with the data, whereas in others the agreement is poorer, perhaps indicating the presence of additional social structure in the network that is not captured by the random graph.
Natural variability of atmospheric temperatures and geomagnetic intensity over a wide range of time scales
Authors: Pelletier Jon D.
Published: December 2002

The majority of numerical models in climatology and geomagnetism rely on deterministic finite-difference techniques and attempt to include as many empirical constraints on the many processes and boundary conditions applicable to their very complex systems. Despite their sophistication, many of these models are unable to reproduce basic aspects of climatic or geomagnetic dynamics. We show that a simple stochastic model, which treats the flux of heat energy in the atmosphere by convective instabilities with random advection and diffusive mixing, does a remarkable job at matching the observed power spectrum of historical and proxy records for atmospheric temperatures from time scales of one day to one million years (Myr). With this approach distinct changes in the power-spectral form can be associated with characteristic time scales of ocean mixing and radiative damping. Similarly, a simple model of the diffusion of magnetic intensity in Earth's core coupled with amplification and destruction of the local intensity can reproduce the observed 1/
f
noise behavior of Earth's geomagnetic intensity from time scales of 1 (Myr) to 100 yr. In addition, the statistics of the fluctuations in the polarity reversal rate from time scales of 1 Myr to 100 Myr are consistent with the hypothesis that reversals are the result of variations in 1/
f
noise geomagnetic intensity above a certain threshold, suggesting that reversals may be associated with internal fluctuations rather than changes in mantle thermal or magnetic boundary conditions.
Self-organized complexity in economics and finance
Authors: Stanley H. E. , Amaral L. A. N. , Buldyrev S. V. , Gopikrishnan P. , Plerou V. , Salinger M. A.
Published: December 2002

This article discusses some of the similarities between work being done by economists and by physicists seeking to contribute to economics. We also mention some of the differences in the approaches taken and seek to justify these different approaches by developing the argument that by approaching the same problem from different points of view, new results might emerge. In particular, we review two newly discovered scaling results that appear to be universal, in the sense that they hold for widely different economies as well as for different time periods: (
i
) the fluctuation of price changes of any stock market is characterized by a probability density function, which is a simple power law with exponent −4 extending over 10
2
SDs (a factor of 10
8
on the
y
axis); this result is analogous to the Gutenberg–Richter power law describing the histogram of earthquakes of a given strength; and (
ii
) for a wide range of economic organizations, the histogram shows how size of organization is inversely correlated to fluctuations in size with an exponent ≈0.2. Neither of these two new empirical laws has a firm theoretical foundation. We also discuss results that are reminiscent of phase transitions in spin systems, where the divergent behavior of the response function at the critical point (zero magnetic field) leads to large fluctuations.
A multitrajectory, competition model of emergent complexity in human social organization
Authors: Read Dwight W.
Published: December 2002

The repeated pattern of emergent human organization at a societal level going from small-scale, egalitarian decentralized societies to complex, stratified, and centralized societies is well-documented in the archaeological record of past societies. In this paper, I outline a multitrajectory model that relates to the broad features of this sequence of societal change. Competition is shown to play a critical role in the way interaction—among decision making, demographic parameters, and social units that organize resource ownership and procurement—either promotes or inhibits change in social organization. Multiagent simulation is discussed as a way to link culturally embedded decision making to emergent properties in the multitrajectory model.
H3PW12O40-functionalized tip for scanning tunneling microscopy
Authors: Song In K. , Kitchin John R. , Barteau Mark A.
Published: December 2002

Recent reports of C60-functionalized metal tips [Kelly, K. F., Sarkar, D., Hale, G. D., Oldenburg, S. J. & Halas, N. J. (1996)Science273, 1371–1373] and carbon nanotube tips [Dai, H., Hafner, J. H., Rinzler, A. G., Colbert, D. T. & Smalley, R. E. (1996)Nature (London)384, 147–151] demonstrate the potential of controlling the chemical identity and geometric structure of tip atoms in scanning tunneling microscopy (STM). This work reports the performance of a heteropolyacid (HPA)-functionalized Pt/Ir tip, which was formulated by contacting a mechanically formed tip with a solution of H3PW12O40molecules. Attachment of an H3PW12O40molecule on the metal tip was confirmed by observing the characteristic negative differential resistance (NDR) behavior of H3PW12O40in tunneling spectroscopy. Atomic resolution images of bare graphite as well as of H6P2W18O62HPA monolayers on graphite were successfully obtained with a Pt/Ir-HPA tip. In the H3PW12O40molecule on a metal tip, it is likely that a terminal oxygen of W⩵O (an oxygen species projecting outward from the pseudospherical H3PW12O40molecule) serves as an atomically sharp and stable tip. Additionally, superimposed superperiodic structures commensurate with the underlying graphite lattice were regularly observed with the modified tips. This result suggests that tip functionalization with these metal oxide molecules may enhance resolution in a fashion analogous to functionalization with C60.