Fractal Electronics for Stimulating and Sensing Neural Networks: Enhanced Electrical, Optical, and Cell Interaction Properties.

Imagine a world in which damaged parts of the body - an arm, an eye, and ultimately a region of the brain - can be replaced by artificial implants capable of restoring or even enhancing human performance. The associated improvements in the quality of human life would revolutionize the medical world and produce sweeping changes across society. In this chapter, we discuss several approaches to the fabrication of fractal electronics designed to interface with neural networks. We consider two fundamental functions - stimulating electrical signals in the neural networks and sensing the location of the signals as they pass through the network. Using experiments and simulations, we discuss the favorable electrical performances that arise from adopting fractal rather than traditional Euclidean architectures. We also demonstrate how the fractal architecture induces favorable physical interactions with the cells they interact with, including the ability to direct the growth of neurons and glia to specific regions of the neural-electronic interface.

Using Fractal Iconography to Emulate Nature's Aesthetics.

This year's cover artists are members of a team of physicists and psy-chologists who create human-centered designs based on psychology experiments that investigate the positive impacts of viewing fractal patterns. These positive impacts include reduced physiological stress levels and enhanced cognitive skills. Here, the team explores the concept of 'fractal iconography' as an approach to employing computers to generate naturalistic art. Adopting this approach, three forms of fractal patterning ('fractal icons') are combined in a variety of ways to generate the rich complexity of nature's scenery. These composite fractals are remarkably effective at conveying nature's aesthetic power.

A randomized controlled trial of the impact of the Teen Council peer education program on youth development.

This paper presents results of an impact evaluation of Teen Council, a program that trains youth as peer educators. Teen Council is designed to help peer educators make healthy sexual and reproductive decisions, increase their confidence and abilities to educate their peers and inspire them to advocate for just sexual policies. The program's impact on these educators was evaluated using a randomized controlled trial. Over 5 years, interested high school students in seven states were randomly assigned to a study condition. An intent-to-treat framework using ordinary least square (OLS) regression was employed to measure program effects. Relative to control, Teen Council youth showed enhanced comfort with their own sexuality, greater comfort with and more frequent communication with parents about sexuality and more positive sexual health behaviors, including accessing reproductive health care and adopting more effective means of contraception. Teen Council youth also reported greater confidence in talking with peers about sexuality and more confidence in their civic engagement skills.

Programmatic prevention of adolescent problem behaviors: the role of autonomy, relatedness, and volunteer service in the Teen Outreach Program.

Explored the mechanisms by which a well-validated intervention to prevent school failure, suspension, and teenage pregnancy produces its effects, using site-level data from 66 sites involving over 1,000 students participating in national replication of the Teen Outreach Program. Multiple informants provided data on operating characteristics of each site. These were then used to explain differences across sites in levels of success in reducing youth problem behaviors using a pre-post design and a well-matched comparison group. In accord with predictions from developmental theory, middle school sites that promoted student autonomy and relatedness with peers and with site facilitators achieved significantly greater levels of success in reducing problem behaviors. Offering volunteer experiences perceived as teaching middle school students new skills and leaving them real choices about the type of work they did was also linked to program success. Although the program was equally successful with students from a wide range of sociodemographic backgrounds, links of program factors to site-level outcomes were found only for middle school but not high school sites. Implications of these findings for the development of programmatic interventions targeted at adolescents are discussed.

Long-term effect of tubal sterilization on menstrual indices and pelvic pain.

OBJECTIVE: To evaluate the long-term effect of tubal sterilization on menstrual indices and pelvic pain. METHODS: Five hundred women undergoing sterilization were interviewed before sterilization, 6-10 months after surgery, and 3-4.5 years later. Four hundred sixty-six non-sterilized comparison women were interviewed in parallel. The study population consisted of low-income, ethnically and regionally diverse women from three participating institutions. RESULTS: When women who were taking oral contraceptives were excluded, no long-term differences was found between sterilized and nonsterilized women in terms of menstrual cycles, bleeding between periods, prolonged or heavy flow, dysmenorrhea, or noncyclic pelvic pain. Hysterectomy was uncommon (3.2%), but statistically more prevalent among sterilized women (4.55%) than nonsterilized women (2.17%) (P = .019). CONCLUSIONS: Tubal sterilization has no long-term effect on menstrual indices or pelvic pain. An increase in severe dysmenorrhea, which emerged as a disturbing but nonsignificant trend at 6-10 months, did not progress over the next 3-4.5 years. Reasons for an increased rate of hysterectomy are not clear, but may be related to a lower threshold for choosing hysterectomy as a treatment option once a woman has been sterilized.

School-based prevention of teen-age pregnancy and school dropout: process evaluation of the national replication of the Teen Outreach Program.

Examined a program designed to prevent adolescent pregnancy, school failure, and dropout using a process model of evaluation to assess with which groups of participants and under what conditions the program was most effective. Students in the Teen Outreach Program of the Association of Junior Leagues and matched comparison students in 35 schools nationwide participated. Sites that highly utilized a volunteer service component, and sites that primarily served older students reported lower levels of student problem behaviors at program exit, after controlling for problem behaviors at entry. These findings occurred only for program youths and not for comparison youths. The connection of volunteer service to reductions in adolescent problem behaviors is interpreted in terms of helper-therapy and empowerment theories. Limitations of the analytic strategy used in this study, as well as techniques for addressing the limitations, are also discussed.

Using the Luker model to explain contraceptive use among adolescents.

PIP: The Luker model specifies that failure to contracept might be deliberate. The determinants of contraceptive behavior are the assignment of advantages and disadvantages to contraceptive use and pregnancy. A subjective probability is given to the likelihood of getting pregnant and to reversing any pregnancy that might occur. Successful risk taking leads to a lower probability of pregnancy and thus more risk taking. Stressful life events or interpersonal situations may change the probabilities. The advantage of this model is its proximity to the actual coital event. The goal is to identify factors related to risk taking. Examination of the model involved a sample of 425 sexually active women aged 13-19 years from a multiservice center for youth in New York City in 1981 who visited the agency at least 1 month prior to the interview. The sample was 36% black, 36% white, 24% Hispanic, and 4% Oriental or other. 77% were enrolled in school and 55% were from intact homes. 38% had professionally employed parents and 14% received welfare. Questions were directed to the likelihood of pregnancy and contraception and the advantages and disadvantages, the likelihood of abortion if pregnancy occurred, and background variables (social and psychological characteristics; situational factors at last intercourse; sexual, contraceptive and pregnancy histories; degree of support from partners, peers, parents; ego development; and knowledge of pregnancy risk and contraception). Reliability of each scale was assessed. The results showed that 26% of women at last coitus had taken a pregnancy risk. These risk takers considered birth control as more disadvantageous and pregnancy more advantageous. The probability of pregnancy at last coitus was considered by risk takers to be lower than non-risk takers. Risk and non-risk takers were at the same risk of pregnancy regardless of subjective perception. 50% thought about pregnancy or contraception at last coitus. 48% reported thinking about the good or bad things about getting pregnant, and 38% actually thought about being pregnant. 9 of 43 variables were related to risk taking. The multivariate models revealed that significant variables were knowledge of welfare history, previous risk taking, ego development, and 5 variables from the Luker model. Adding the scale for stressful life events did not affect the results. The Luker model and developmental reasons for pregnancy risk are supported. There was moderate support for Luker's feedback mechanism, but good longitudinal data are necessary for accurate cost accounting. The assumption that motivation to attend a clinic will affect all future coital acts is deceptive.^ieng

Changes in menstrual symptoms among sterilized and comparison women: a prospective study.

Changes in menstrual parameters after tubal sterilization were analyzed in ethnically diverse, poor women from three geographic areas in the United States. Two large suitable comparison groups were similarly studied. Menstrual cycles, duration of menstrual flow, and bleeding between periods were unchanged in the sterilization and comparison groups. The prevalence of dysmenorrhea increased in 10.8% of sterilized women, compared with 2.1% in the comparison groups. This difference was even more significant--16.4 and -0.5%--when usage of oral contraceptives and intrauterine devices was discounted. There was a nonsignificant increase in noncyclic pelvic pain.

Beliefs about contraceptive sterilization among low-income urban women.

Among a group of low-income clinic patients planning to be sterilized, the vast majority--95 percent--reported believing that sterilization is the surest way to avoid getting pregnant and that it is safer than other contraceptive methods. Among a comparison group who also wanted no more children but did not plan to be sterilized, the majority also held these beliefs, but the proportion was lower (76-80 percent). In both groups, however, only between 64 and 70 percent knew that sterilization makes it impossible to have children in the future. Between 63 and 68 percent of the women in the sterilization group believed that having the operation would improve their family relationships, emotional state and other aspects of their lives, but only 35-58 percent of the comparison group held these beliefs. On the other hand, women in the comparison group were more likely than those in the sterilization group to believe that sterilization has negative health and psychological effects--for example, changes in menses (more bleeding or cramping) or defeminization. The beliefs held by both groups suggest that it is a conviction regarding the advantages of sterilization, rather than a relative unawareness of the disadvantages, that distinguishes women who plan to be sterilized from those who, although they want no more children, do not have similar plans. The study results have implications for family planning professionals: Counselors need to be aware that some women seeking sterilization may not understand its permanency or may have an unrealistic appraisal of its potential effect on their lives.(ABSTRACT TRUNCATED AT 250 WORDS)

Teenagers' perceived and actual probabilities of pregnancy.

This study sought to determine how teenagers' actual and perceived probabilities of pregnancy are related. Data were collected from interviews with 425 women aged nineteen or younger who attended the Door, a multiservice center for youth in New York City. Subjects were asked to estimate their likelihood of becoming pregnant the last time they had intercourse, and to indicate the dates of both last intercourse and last menstrual period in order to determine their objective and subjective assessments of risk of pregnancy. It was found that the perceived probability of pregnancy was not highly correlated with actual risk: the distributions of perceived probability of pregnancy were nearly identical for both those who were and were not at actual risk. Moreover, respondents' level of knowledge about the timing of ovulation was not significantly related to the accuracy of their risk assessment. The findings also indicate that teenagers' use of contraception is guided more by their perceived risk of pregnancy than by the actual risk. Policy implications are discussed.

PIP: The relation between teenagers' actual and perceived probabilities of pregnancy was investigated. Data were collected from interviews with 425 women aged 19 or younger, who attended The Door, a multiservice center for youth in New York City. Subjects were asked to estimate their likelihood of becoming pregnant the last time they had intercourse, and to indicate the dates of both their last intercourse and last menstrual period, in order to determine both their objective and subjective risk of pregnancy. The perceived probability of pregnancy was not highly correlated with actual risk: the distributions of perceived probability were nearly identical for both those who were and who were not at actual risk. Less than 1/2 the sample correctly perceived their risk of pregnancy. About 1/3 correctly thought they not at risk for pregnancy at last coitus, and 15% were accurate in thinking that they were at risk. However, 40% incorrectly thought they were at risk for pregnancy, the "worries," and 14% thought incorrectly that they were not at risk for pregnancy, the "dangerousy misinformed." Moreover, respondents' level of knowledge about the timing of ovulation was not significantly related to the accuracy of their risk assessment. Teenagers' use of contraception is guided more by their perceived risk of pregnancy than by the actual risk. These findings offer additional evidence for educational efforts that go beyond providing information about ovulation; such interventions should teach teenagers how to apply this knowledge to themselves and emphasize that there really is no "safe period" for unprotected intercourse.

Strategies for evaluating a contraceptive service for teenagers.

A program model outlining goals and objectives and activities or processes by which these goals will be reached is essential to ensure effective evaluation of a contraceptive program for adolescents.

PIP: This article discusses methods of evaluating adolescent contraceptive programs in order to improve their effectiveness. Development of specific goals, and objectives and processes by which these goals will be reached is essential in constructing a program model that is evaluable. The creation of the model should include program input, processes, output, and primary, intermediate and long term effects. Such a model can then be used to evaluate whether goals are being accomplished in addition to commonly used data collection systems such as service statistics. Special sampling studies can be utilized to assess changes in patient knowledge and attitudes. Methods of measuring various indicators such as clinic attendance, contraceptive continuation, and method continuation are described. Problems in defining and calculating pregnancy rates as well as measures for program continuation is discussed. An effective program model necessitates cooperation from administrators, service providers, and evaluators in facilitating program implementation and evaluation. Internal obstacles to the model, such as staff resistance to data collection, present a challenge to evaluators and requires that necessary paperwork be simplified and well-organized.

Age variation in use of a contraceptive service by adolescents.

During the past decade, much has been written about adolescents' use of contraception and their experience of pregnancy. Few researchers, however, have distinguished between the experiences of older and younger adolescents. The purpose of this paper is to provide such a comparison. The data were collected during more than 7,000 visits made by 4,318 patients during almost 5 years of operation of an adolescent contraceptive service in the Washington Heights area of New York City. Characteristics of four groups--14 years and younger, 15-17 years, 18-19 years, and 20-21 years--were examined. The youngest teens initiated sexual intercourse 4 years earlier than the oldest group. Among those 14 or younger, 87 percent had never used contraception, and 9 percent had been pregnant. In the oldest group, more than two-thirds had used a contraceptive method, and three-fifths had already experienced a pregnancy. Results of multivariate analyses indicate that older teens are more likely to come to the clinic for contraception and to be consistent users of the first method of contraception that they select. On the other hand, younger teens are significantly more likely to revisit the clinic and to be pregnant at a second or later visit.

Social and psychological perspectives on voluntary sterilization: a review.

This paper reviews social science research on the antecedents and consequences of voluntary sterilization. The major conclusions are that socioeconomic status has little impact on the decision to be sterilized and that sterilizations are rare among those without sons and among male non-whites. Significant others are important sources of encouragement and information, and good marital relations increase the likelihood of having the procedure performed. Most acceptors experience no change in sexual activity, quality of marital relationships, or work-related behavior, and few regret their choice. Negative consequences are more likely among those in India, those coerced into having a sterilization, those who did not understand the consequences of the procedure, those with health complications after sterilization, and those couples who have unstable marriages or who disagree about sterilization.

PIP: This paper reviews social science research on the antecedents and consequences of voluntary sterilization. The major conclusions are that socioeconomic status has little impact on the decision to be sterilized and that sterilizations are rare among those without sons and among male nonwhites. Significant others are important sources of encouragement and information, and good marital relations increase the likelihood of having the procedure performed. Most acceptors experience no change in sexual activity, quality of marital relationships, or work-related behavior, and few regret their choice. Negative consequences are more likely among those in India, those coerced into having a sterilization, those who did not understand the consequences of the procedure, those with health complications after sterilization, and those couples who have unstable marriages or who disagree about sterilization. An inverse relationship between sterilization and socioeconomic status seems to result when other methods of contraception are not easily available to those of lower socioeconomic status. In other instances the procedure appears to be 1st adopted in upper socioeconomic groups and then these groups are emulated in the lower classes. Very few couples without children or with only 1 child have voluntary sterilizations. On the other hand, most sterilizations occur among high parity couples. Religion does not appear to be an influential factor in choosing sterilization. Although it may not effect individual behavior, some religious institutions' opposition to sterilization may effect its availability,e.g. in countries where Catholicism or Islam dominate. The frequency of female sterilization is about the same among blacks, whites and Hispanics, although a little higher for blacks and Hispanics. The low rate of sterilization among black and Hispanic men is usually explained by a culture value, e.g. the relationship between ability to conceive and masculinity. The 3 major motivations for being sterilized are: financial, completed family size and dislike of other contraceptive methods. Research has not yet shown the importance of attitudinal and personality correlates of voluntary sterilization. The most consistent personality factor is that sterilized men have a lower than average need for social approval. Data support the hypothesis that there may be hidden impacts of sterilization that have been only infrequently captured. Some studies showed decreased sexual functioning and elevated levels of psychological disturbance among men who reported being satisfied with their vasectomies.

Sexually active but not pregnant: a comparison of teens who risk and teens who plan.

PIP: Previous studies have compared contraceptive users with nonusers, and pregnant teens with nonpregnant ones. This paper reports the findings of a study of a sample of 119 women aged 21 and under who visited the Young Adult Clinic at Columbia-Presbyterian Medical Center in New York City during 1981. All of these women had been sexually active for a year or longer, but had never been pregnant. The expectation that such a sample would include mainly consistent users of contraception was unwarranted; within this special population were found young women who had never used contraception or who had only been sporadic users, as well as the consistent users. Moreover, there are many more similarities than differences among these groups, and their stated motivations for not becoming pregnant are the same. The consistent contraceptors were more likely to live with their mothers, to have mothers who worked, to indicate that their parents would help them have an abortion, and to indicate they would have an abortion should they become pregnant. The similarities between these young women are very important for programs, which often rely heavily on stated motivation or even on a clinic visit as evidence that a young woman intends to use a birth control method. There is nothing here to support this simple view. Instead the notion is substantiated that many adolescents may lack cognitive consistency on this subject or may lack the future orientation to be effective contraceptive users.^ieng

The nurse-midwife in a contraceptive program for adolescents.

PIP: Documents nurse midwives' role in providing contraceptive and counseling services to young people who are most at risk for unwanted pregnancy. Data studied is from a clinic which operates during the late afternoon and early evening in an urban hospital. A physician is responsible for the overall supervision of the clinic, but nurse midwives play a major role in patient care and provision of services. The data compares nurse midwives and physicians in the clinic with regard to patient load, characteristics, contraceptive methods chosen, revisit patterns, and problems. Patients of both nurse midwives and physicians had similar characteristics and past histories. Findings show that nurse midwives often carry the largest share of the patient load and have maintained slightly higher revisit rates and similar oral contraceptive continuation rates, in comparison with physicians. Most important, patients of nurse midwives are no more likely than those of physicians to report method related problems. The lack of significant differences is regarded as encouraging. This suggests that nurse midwives can play a valuable role in the increasing number of counseling and contraceptive programs for young people.^ieng

A comparison of responses to adolescent-oriented and traditional contraceptive programs.

PIP: Compares characteristics of teenage patients attracted to a traditional family planning clinic and an adolescent oriented clinic, and studies the success of each in promoting contraceptive use. Data were collected from 2 clinics operating in the same physical site in an urban hospital. The traditional family planning clinic (Day Clinic) serves both teenage and older women. The Young Adult Clinic (YAC) serves only patients 21 or younger and operates 2 evenings a week. The 2 clinics have an overlapping staff and medical services are identical in each, except that patients of the YAC are offered counseling, and admission to the clinic is simplified. The data from each clinic covers 2 years. Results show that the most important difference between the clinics is that the YAC attracts 3 1/2 times as many teens as the Day Clinic. Different background characteristics of the patients account for differences in contraceptive method utilization, revisit patterns, and pregnancy rates within the 2 clinics, rather than clinic differences. YAC patients are likely to be younger, and less likely to have been pregnant before. Thus, the YAC offers more of an opportunity for primary prevention of pregnancy. The authors concluded that the major benefit of offering an adolescent only evening clinic lies in its ability to attract young women who might not otherwise receive services.^ieng

The value of children to children.

The data included in this paper demonstrate that the Hoffman scheme for conceptualizing the values of children applies about as well to responses from children aged 10 to 18 as it does to the responses of adults. Some of the same variables related to adult perceptions of values of children show similar relationships among children. Data are included from both mothers and children in the families sampled. Alternative wording of the questions about the values of children indicates that while children and mothers may be aware of the dominant cultural values, they may not have internalized these for themselves.

Adolescents' Use of a hospital-based contraceptive program.

PIP: Reports on a recent study of a 3-year experience with a hospital based adolescent contraceptive program, focuses on the characteristics, contraceptive practices, patterns of clinic attendance and pregnancy rates of the patients served. The program under consideration offers family planning services via a regular day clinic, and also through an evening Young Adult Clinic. Analysis of usage patterns over the period has provided insight into several important factors related to the provision of contraceptive services to adolescents. The potential impact of a hospital based program to attract young people in need of services has also been demonstrated. Despite these achievements in engaging youth in responsible reproductive behavior, certain patterns deserving of further attention are evident. For example, it was found that more than 1/2 of the young women attending the program have had at least 1 pregnancy before coming for care. Moreover, the median interval from the onset of sexual activity to the time of the 1st clinic visit was found to be 9 months. Another problem has been the failure of approximately 4 out of every 10 initial visitors to return for a 2nd appointment. At the 2nd or later visit only 9% of those attending the program were found to be pregnant, but of those the majority were not using a contraceptive method at the time of the conception. These and other shortcomings in adolescent family planning behavior suggest the need for further research into the patterns of contraceptive use and nonuse.^ieng

The effectiveness of contraceptive programs for teenagers.

This paper critically reviews the effectiveness of adolescent family planning programs in the United States. Various models for evaluating family planning programs and the findings from empirical studies of adolescent programs are reviewed. During the past decade there have been major increases in the availability and utilization of contraceptive services by adolescents. Most of those who are sexually active are now aware that these services exist. Program continuation rates among adolescents are not high, in part, because of the sporadic nature of adolescent sexual activity. Data on contraceptive continuation and pregnancy rates in these programs are limited, since few studies follow up clinic noncontinuers. Among clinic continuers pregnancy rates are relatively low, suggesting that at least some programs are effective in reducing pregnancy and/or fertility rates (number of children born) in their target populations. Ecological analyses seem to indicate that programs have had an impact on adolescent marital fertility.

PIP: This article briefly reviews the literature on methods of evaluating international family planning programs and uses the findings as a framework for summarizing available information on the effectiveness of adolescent contraceptive programs in the U.S. Current models for evaluating contraceptive programs usually employ systems approaches, with increasing emphasis being placed on global impacts such as lower fertility or socioeconomic change. Recent empirical studies of adolescent programs in the U.S. have provided information on the aviailability and utilization of services, changes in knowledge levels of adolescents, clinic and contraceptive continuation, and pregnancy rates and fertility. Major increases have occurred in the past decade in knowledge and use of services by teenagers, but program continuation rates are not high because of the sporadic nature of adolescent sexual activity. Few studies follow up clinic noncontinuers, limiting available data on contraceptive continuation and pregnancy rates. Studies of the impact of family planning programs on adolescent fertility using varied methodologies suggest that at least some programs are effective in reducing pregnancy or fertility rates among teenagers. A comprehensive evaluation model for adolescent programs is needed which adapts existing frameworks to the particular interests and needs of adolescent services, addressing such problems as the high proportion of sexually active teenagers not receiving services, inadequate knowledge of pregnancy risks and contraceptive usage, late approach to clinic services, and sporadic use of contraception.