Characterization of multiscroll attractors using Lyapunov exponents and Lagrangian coherent structures.

The present work aims to apply a recently proposed method for estimating Lyapunov exponents to characterize-with the aid of the metric entropy and the fractal dimension-the degree of information and the topological structure associated with multiscroll attractors. In particular, the employed methodology offers the possibility of obtaining the whole Lyapunov spectrum directly from the state equations without employing any linearization procedure or time series-based analysis. As a main result, the predictability and the complexity associated with the phase trajectory were quantified as the number of scrolls are progressively increased for a particular piecewise linear model. In general, it is shown here that the trajectory tends to increase its complexity and unpredictability following an exponential behaviour with the addition of scrolls towards to an upper bound limit, except for some degenerated situations where a non-uniform grid of scrolls is attained. Moreover, the approach employed here also provides an easy way for estimating the finite time Lyapunov exponents of the dynamics and, consequently, the Lagrangian coherent structures for the vector field. These structures are particularly important to understand the stretching/folding behaviour underlying the chaotic multiscroll structure and can provide a better insight of phase space partition and exploration as new scrolls are progressively added to the attractor.

A comparison of problems reported by persons with cancer and their same sex siblings.

Problem reporting rates of 180 persons with cancer (PWC) were compared with those of their closest in age same sex cancer-free siblings living outside their households for the same time periods. PWC had significantly higher reporting rates for physical, activities of daily living, nutrition, and emotional problems and a significantly lower rate for family problems. Sibling problem reporting rates, which indicate the likelihood that PWC would have experienced similar problems without a diagnosis of cancer, were highest for physical, emotional, employment, and family problems suggesting that noncancer factors are especially likely to play a role in those types of problems. Regression analyses showed that female and younger PWCs tended to report more problems than their siblings suggesting that they were more affected by cancer and its treatments than were other types of PWC.

Beliefs, social normative influences, and compliance with antihypertensive medication.

We explored the relationship between beliefs and social normative influences and self-reported hypertension medication compliance using questionnaire items based on the belief intention model of Ajzen and Fishbein. Persons for whom antihypertensive medication had been prescribed were asked to agree or disagree with statements about taking their medicine. Respondents were a subset of participants in a 1980 survey of risk factors for heart disease in two Pennsylvania counties. Highly significant differences between compliant and noncompliant individuals were observed for all items except one referring to cost. A stepwise multiple logistic regression analysis was performed with age, sex, and the belief and social normative items as independent variables, and reported compliance as the dependent variable. Three variables, age, "taking my blood pressure medicine as the doctor told me would not be necessary when my blood pressure is normal," and "your family wants you to take your blood pressure medicine as the doctor told you," entering into the equation in that order, significantly improved discrimination between compliant and noncompliant persons. The questionnaire's success may have resulted from moving beyond assessing participant's knowledge or beliefs about hypertension in the abstract to ascertaining the direct relevance of these beliefs to their taking their medicine.

Creating an agenda for research and evaluation: HIV service delivery, the Ryan White CARE Act, and beyond.

HRSA, AHCPR and NCAP convened a working meeting in November 1992, to discuss creation of a national agenda for research and evaluation on HIV service delivery systems that are cost-effective, responsive to the needs of the diverse populations affected by the epidemic, and reflective of the lessons learned so far. In this article, the interests and goals of the conveners are described, the meeting's process and outcomes are discussed, and the nine key study areas that were identified and chosen by the meeting participants are presented. It is hoped that this article will stimulate further interest among private and public funders and among the research community in fostering the implementation of HIV service delivery-related research and evaluation studies. If this is accomplished, decision-makers will be better enabled to make informed and responsive policy decisions.

Developing cancer control capacity in state and local public health agencies.

In 1986, the National Cancer Institute began a major grant program to enhance the technical capabilities of public health departments in cancer prevention and control. This effort, commonly referred to as "capacity building" for cancer control, provided funding to support eight State and one local health department. The program focused on developing the knowledge and skills of health department personnel to implement intervention programs in such areas as smoking cessation, diet modification, and breast and cervical cancer screening. The grants ranged from 2 to 5 years in length, with funding of $125,000 to $1.6 million per grant. The total for the program was $7.4 million. While the priorities set for these grants were nominally similar, their capacity building activities in cancer prevention and control evolved into unique interventions reflecting the individual needs and priorities of each State or locality. Their experiences illustrate that technical development for planning, implementing, and evaluating cancer prevention and control programs is a complex process that must occur at multiple levels, regardless of overall approach. Factors found to contribute to successful implementation of technical development programs include* commitment of the organization's leadership to provide adequate support for staff and activities and to keep cancer prevention and control on the organizational agenda,* the existence of appropriate data to monitor and evaluate programs,* appropriately trained staff,* building linkages with State and community agencies and coalitions to guide community action,* an established plan or process for achieving cancer control objectives,* access to the advice of and participation of individual cancer and health experts,* an informed State legislature,* diffusion of cancer prevention and control efforts,and* the ability to obtain funds needed for future activities.

States' responses to Title II of the Ryan White CARE Act.

Title II of the Ryan White Comprehensive AIDS Resources Emergency (CARE) Act of 1990 provides formula-based grants to States to help them improve the quality, availability, and organization of health care and support services for people with human immunodeficiency virus (HIV) infection. This article reviews State expenditures during the first year of CARE Act funding (April 1991-March 1992) within the context of Title II guidelines and the federally funded grant programs that preceded and helped shape Title II. The authors also discuss future challenges that require development of resources, the assessment of program impact, and the evaluation of the quality and appropriateness of HIV-related services. Ninety-one percent of the $77.5 million awarded to States during fiscal year 1991 went for the provision of medical and support services through HIV care consortia, drug reimbursement programs, home and community-based care programs, and health insurance initiatives. The remaining monies were used for planning, evaluation, and program administration. Forty States allocated $38.9 million for the establishment of HIV care consortia to assess service needs and to develop comprehensive continuums of health and support services in the areas most affected by HIV disease. Fifty States allocated an additional $28.3 million for the continuation or expansion of FDA-approved drug therapies for low-income people with HIV infection. Twenty-five States allocated $2.2 million for the provision of home- and community-based health services, and 16 States allocated $1.3 million for programs that help low-income people with HIV infection to purchase or maintain health insurance coverage.

First year of AIDS services delivery under Title I of the Ryan White CARE Act.

This is a review of (a) the emergency assistance for ambulatory HIV medical and support services provided in the first year by eligible metropolitan areas (EMAs) funded under Title I of the Ryan White Comprehensive AIDS Resources Emergency (CARE) Act of 1990, (b) the varied responses and processes by which the 16 urban areas receiving Title I funds in 1991 met legislative mandates, (c) the central nature of planning councils under Title I and their formation and functioning, and (d) issues related to current implementation and future expansion of Title I to additional eligible metropolitan areas. Integral to the review is a brief discussion of the history of AIDS and HIV infection, particularly in cities receiving CARE Act funding, an overview of Title I requirements, and a description of the organizational structures cities are using to implement Title I. Information on Title I EMAs is based on analysis of their 1991 applications, bylaws of their HIV service planning councils, intergovernmental agreements between Title I cities and other political entities, and contracts executed by Title I grantees with providers for the delivery of services. Interviews with personnel in several Title I EMAs, including planning council members and grantee staff members, provided additional information. This is the first descriptive accounting of activities related to the 1991 applications for and uses of Title I funds, and the administrative and service issues related to this process.

Predicting substance abuse among youth with, or at high risk for, HIV.

This article describes data from 4,111 males and 4,085 females participating in 10 HIV/AIDS service demonstration projects. The sample was diverse in age, gender, ethnicity, HIV status, and risk for HIV transmission. Logistic regression was used to determine the attributes that best predict substance abuse. Males who were younger; HIV positive; homeless; involved in the criminal justice system; had a sexually transmitted disease (STD); engaged in survival sex; and participated in risky sex with men, women, and drug injectors were most likely to have a substance abuse history. For females, the same predictors were significant, with the exception of having an STD. Odds ratios as high as 6 to 1 were associated with the predictors. Information about sexual and other risk factors also was highly predictive of substance abuse issues among youth.

Factors associated with delays in accessing HIV primary care in rural Arkansas.

While debate continues at what stage of human immunodeficiency virus (HIV) disease to begin combination antiretroviral therapy, a number of clinical and public health benefits are linked to early entry into primary care soon after first testing HIV positive. However, HIV-infected patients continue to test late and delay entry into care. We used routinely collected demographic and clinical information to examine which factors are associated with delays in seeking care in a predominantly rural, economically poor area of Arkansas. The study population is 75% African American and male and 70% lack health insurance; nearly one fourth were referred from prison. At diagnosis, two thirds of the population had CD4 counts below 500 cells per microliter. Days from initial HIV diagnosis to entry into care declined from a median of 178 in 1994 to 24 in 1998. In 1998, 75% of the population entered into primary care within 2 months of diagnosis. However, CD4 counts at HIV diagnosis also declined in this period, from a median of 427 in 1995 to 208 cells per microliter in 1998. More recent year of diagnosis was associated with a shorter delay in seeking care; males, and individuals lacking health insurance took significantly longer to enter into care than females and those with insurance, respectively. Our univariate finding of extensive delays in seeking care in the prison population did not hold in the multivariate analysis. We found significant delays in time to initial HIV diagnosis, and further considerable delays in males and those lacking health insurance in the time taken to enter into primary care.

Who receives Ryan White CARE Act services? A demographic comparison of CARE act clients and the general AIDS population.

This study examines the extent to which health and social service providers funded by the Ryan White Comprehensive AIDS Resources Emergency (CARE) Act serve women, minorities, and other vulnerable populations emphasized by the legislation. Demographic characteristics of AIDS-diagnosed clients served by CARE Act-funded providers in four metropolitan areas and two states are compared with Centers for Disease Control and Prevention estimates of AIDS prevalence. Clients of CARE Act-funded providers tend to reflect the demographics of local HIV/AIDS epidemics. Where differences exist, CARE Act clients are more likely to be women and minorities and less likely to be injecting drug users. CARE Act-funded providers are effectively reaching most medically underserved populations.

Service use patterns of youth with, and at high risk for, HIV: a care typology.

This paper uses confirmatory structural equation models to develop and test a theoretical model for understanding the service utilization history of 4679 youth who received services from 10 national HIV/AIDS demonstration models of youth-appropriate and youth-attractive services funded by the Special Projects of National Significance (SPNS) Program, HIV/AIDS Bureau, Health Resources and Services Administration. Although the projects differ from one another in the areas of emphasis in their service models, each is targeted to youth at high risk for HIV, or those youth who have already contracted HIV. Collectively, the projects represent a comprehensive adolescent HIV service model. This paper examines the characteristics of the services provided to young people ranging from outreach to intensive participation in medical treatment. Major typologies of service utilization are derived empirically through exploratory factor and cluster analysis methods. Confirmatory structural equation modeling methods are used to refine the exploratory results using a derivation and replication strategy and methods of statistical estimation appropriate for non-normally distributed service utilization indicators. The model hypothesizes that youth enter the service system through a general construct of connectedness to a comprehensive service model and through service-specific methods, primarily of outreach or emergency services. Estimates are made of the degree to which a comprehensive service model drives the services as opposed to specific service entry points.

Ensuring the dissemination of Cancer Control Demonstration Projects for Farmers.

The successful dissemination of the Cancer Control Demonstration Projects for Farmers depends not only on the effectiveness of the grants funded under this program but also on factors external to the grants. In this article, three health-related external factors are examined: the cancers amenable to prevention and control, intervention methodologies, and the organization of rural health care. Changes between 1989 and 1996 in each of these factors and the effects of these changes on the dissemination of grantee findings to public health and medical practitioners are described. Suggestions are offered on actions that the National Institutes for Occupational Safety and Health can undertake to increase the likelihood of adoption of grantee findings.

A typological approach to the study of rural HIV service delivery networks.

Despite the rapid growth of AIDS cases in nonmetropolitan areas, little is known about the characteristics and needs of HIV-positive rural residents or how rural areas are responding to the epidemic. This paper proposes a typology for distinguishing among rural environments and examining variations in HIV service networks. The typology identifies three dimensions that have a major effect on the development of rural HIV service networks: degree of rurality, the prevalence of AIDS, and the epidemiological and demographic characteristics of the infected populations. Data from four case studies are used to illustrate how variations in rural environments can affect the organization and delivery of HIV/AIDS care. The typology contributes to public policy discussions by identifying key attributes of rural environments that influence program planning and implementation and the transferability of service delivery models.

Delivery of oral health care through the Ryan White CARE Act to people infected with HIV.

The Ryan White Comprehensive AIDS Resources Emergency (CARE) Act of 1990 was passed by Congress "to improve the quality and availability of care for individuals and families with HIV disease." The act targets those individuals infected with HIV who lack financial resources to pay for care. While provision of oral health care is not mandated by the legislation, many oral health services are supported through five different programs receiving CARE Act funding. Legislative mandates, program guidance materials, grant applications, and other related materials were reviewed to analyze oral health care services supported or proposed through the CARE Act. In fiscal year 1991, an estimated $5.8 million of the total CARE Act funds ($229.6 million) were used for oral health care, and there is evidence that oral health concerns will receive increasing attention by grantees in future years. Opportunities exist for local oral health professionals to become involved in CARE Act programs and in the priority development process. It is possible that CARE Act grantees will serve as catalysts for the development of partnerships between private practitioners and public sector programs--relationships that could lead to improved access and quality of care for people with HIV infection.

Movement patterns of persons with HIV receiving treatment in public clinics in the Southern Health Region, Puerto Rico.

PIP: A survey conducted among 187 HIV-infected patients from publicly supported HIV clinics in the Puerto Rican Southern Health Region (SHR) failed to substantiate health planners' concern that this group travels frequently to the US to receive medical services. Respondents were questioned about all places of residence and all sites of HIV treatment in the past 12 months. Movement was defined as being anywhere outside of the SHR for 2 weeks or longer. 7% of the sample had moved at least once in the past year; 4% had moved outside the SHR but within Puerto Rico, while 3% had been in the continental US. Compared to the heterosexual risk group, intravenous drug users and men who have sex with men were 7-8 times more likely to have moved. The attainment of at least a high school education was also significantly and independently associated with increased probability of movement. Medical care was not identified by any of these respondents as the primary reason for travel. 58% indicated they were in their current place of residence to be near family, friends, and relatives. Both the small sample size and the low socioeconomic status of respondents may have limited the ability of this study to identify the so-called "air bridge," however.^ieng

Does palliative care improve outcomes for patients with HIV/AIDS? A systematic review of the evidence.

BACKGROUND: The need for palliative care in HIV management is underlined by the high prevalence of pain and symptoms, the toxicity, side effects, and virological failure associated with antiretroviral therapy, emergence of co-morbidities, continued high incidence of malignancies, late presentation of people with HIV disease, and the comparatively higher death rates among the infected individuals. METHODS: A systematic review was undertaken to appraise the effect of models of palliative care on patient outcomes. A detailed search strategy was devised and biomedical databases searched using specific terms relevant to models of palliative care. Data from papers that met the inclusion criteria were extracted into common tables, and evidence independently graded using well described hierarchy of evidence. RESULTS: 34 services met the inclusion criteria. Of these, 22 had been evaluated, and the evidence was graded as follows: grade 1 (n = 1); grade 2 (n = 2); grade 3 (n = 7); grade 4 (n = 1); qualitative (n = 6). Services were grouped as: home based care (n = 15); home palliative care/hospice at home (n = 7); hospice inpatient (n = 4); hospital inpatient palliative care (n = 4); specialist AIDS inpatient unit (n = 2); and hospital inpatient and outpatient care (n = 2). The evidence largely demonstrated that home palliative care and inpatient hospice care significantly improved patient outcomes in the domains of pain and symptom control, anxiety, insight, and spiritual wellbeing. CONCLUSIONS: Although the appraisal of evidence found improvements across domains, the current body of evidence suffers from a lack of (quasi) experimental methods and standardised measures. The specialism of palliative care is responding to the clinical evidence that integration into earlier disease stages is necessary. Further studies are needed to both identify feasible methods and evaluate the apparent beneficial effect of palliative care on patient outcomes in the post-HAART era.