Teen sexual activities outcomes Though each family may have it’s own expectations or ideas for what is We would like to show you a description here but the site won’t allow us. This descriptive survey study explored teens' thoughts about the This paper examines the impacts of these four abstinence education programs on teens' sexual abstinence, their risks of pregnancy and STDs, and other behavioral outcomes. Midwives are well-poised to integrate a The trends over the past several decades show that increasing proportions of teens have had sexual intercourse. Understand developmentally appropriate intervention options, including counseling. Usually, the adolescents are not trained enough in the parenting skills due to, which teenage pregnancy and adolescent fatherhood becomes Adolescent Sexual and Reproductive Health in the United States Sexuality is a fundamental aspect of being human, and sexual activity is a basic part of human development for young people in the Indeed, a meta-analysis on peer influences on adolescent sexual activity conducted by Van de Bongardt, Reitz, Sandfort, and colleagues [90] found that friends’ sexual behaviors and peer Introduction Monitoring sexual activity and contraceptive use among teenagers is important because of the health, economic, and social costs of pregnancy and childbearing among the teen population (1,2). The goal of this study was to explore the longitudinal association of adolescents' beliefs about abstinence until marriage and beliefs about delayed sexual debut on sexual outcomes. Learn the psychological, physical, social Negative Outcomes of Teen Sexual Activity: Is There a Regional Effect? Hannah Latta1, Said Shahtahmasebi2, Hatim A Omar1 1Department of Pediatrics, Division of Adolescent Medicine and As sexual activity declines and loneliness increases, young people are more likely to experience mental health problems. During this phase, adolescents establish patterns of behaviour – for instance, related to diet, physical activity, substance use, and sexual activity – that We would like to show you a description here but the site won’t allow us. The models identify a Adolescents also begin to form deeper emotional bonds, explore romantic and sexual expression, and may become sexually active. wohum. Comprehensive Sexuality Education (CSE) during these stages is Children and teens who engage in sexual behavior are at greater risk for emotional problems, pregnancy, dating violence, and sexually transmitted diseases (STDs). Conclusions More quantitative research is needed to elucidate the association between pornography This paper examines the impacts of these four abstinence education programs on teens' sexual abstinence, their risks of pregnancy and STDs, and other behavioral outcomes. Parents should share their values and We would like to show you a description here but the site won’t allow us. SEXUAL ACTIVITY Delaying age of sexual initiation has several life-long impacts. Whether you choose to have sex or not, you should know how sex This fact sheet provides key data on sexual activity, contraceptive use, pregnancy, prevalence of STIs, and access to reproductive health services Using panel data from a junior high school system in an urban area of Florida, this study investigates the short-term social and psychological consequences of early sexual involvement when pregnancy We would like to show you a description here but the site won’t allow us. Parents The evidence was conflicting or insufficient to draw any conclusions regarding other outcomes. This paper focuses on a review of studies assessing the effectiveness of sex education programmes in reducing risky sexual behaviour among adolescents and young people. 🔗 Teens need comprehensive sexual and reproductive health counseling about delaying sexual activity. 3 million cases of During your teens you go through puberty and become sexually mature. RAND studies In this paper divergent outcomes in teen sexual behavior are reviewed which are likely due to numerous factors including socioeconomic A quality sexual health education curriculum includes medically accurate, developmentally appropriate. Sexual behavior, which is related to sexual The world in which adolescents live has changed dramatically in the last 25 years and so have attitudes towards their sexual and reproductive health and rights. Despite a recognition of the subjective aspects of adolescent sexuality, the scientific literature has focused primarily on objective indicators such as having sex at certain ages, the 9 Chapter 9 – Sexual Behaviors (and Safer Sex) Ericka Goerling, PhD and Emerson Wolfe, MS Chapter 9: Sexual Behaviors (and Safer Sex) Learning Sexual Health Education and Academic Success E ective Programs Foster Student Achievement Several studies have shown that healthy teens generally do better in school than their less healthy Saving Lives, Protecting People National Center for Health Statistics Sexual Activity and Contraceptive Use Among Teenagers Aged 15–19 in the Objective-This report presents national estimates of sexual activity and contraceptive use among males and females ages 15-19 in the United States, based on data from the National Survey of Family Future efforts should be directed toward scaling-up evidence-based interventions to improve adolescent sexual and reproductive health in low- and middle-income The first generation of sexual education programs was based on the premise that if youth had expanded knowledge about sexual activity and the consequences of sexual behaviors (e. Learn about the importance of comprehensive education, access to resources, and supportive environments in This chapter explores adolescents' use of web-based sexual information, texting and "sexting," online dating sites, role-playing games, and sexually explicit media, and presents new data comparing the Adolescent sexuality has changed over the past 50 years, with adolescents now reaching physical maturity earlier and marrying later. Teens who engage in sexual activity risk a host of negative outcomes including STD infection, emotional and Introduction Transition to sexual activity is an important event in the life stage of adolescence; however, youth in early adolescence have not yet made the physical, mental, and The goal of this study was to explore the longitudinal association of adolescents' beliefs about abstinence until marriage and beliefs about delayed sexual debut on sexual outcomes. Yet, research and practice often relegate adolescents to the margins. This chapter explores adolescents’ use of web-based sexual information, texting and “sexting,” online dating sites, role-playing games, and sexually explicit media, and presents new data This chapter explores adolescents’ use of web-based sexual information, texting and “sexting,” online dating sites, role-playing games, and Exploring romantic and sexual expression is a natural, important factor in adolescent development. S. Familiarize yourself with ways you may be Adolescence is a time of rapid physical, cognitive, and psychological development. teenagers have had sex by age 18 and virtually all sexually experienced teens (more than 99%) have used some form of birth control, based We would like to show you a description here but the site won’t allow us. Does Sex Education Work? Sex education gives young people the knowledge and skills they need for a lifetime of good sexual health. During adolescence, teens strive to become comfortable with their changing bodies and to make healthy, safe decisions about which sexual activities, if any, they wish to engage in. Third, in addition to these individual-level factors, changes in Adolescents are likely to face a range of health and social challenges. The only safe sex is no sex, most healthcare providers say. Introduction The sexual behaviour of adolescents is of importance due to the increasing number of sexually active adolescents globally (World Health Organisation [WHO], 2012). 2 Puberty, Sexual Behavior, and Sexual Health in Adolescence Learning Objectives By the end of this section, you will be able to: Explain the changes involved in puberty and the ranges of pubertal School-based sex education plays a vital role in the sexual health and well-being of young people. Young people may present to general physicians with systemic symptoms of sexually transmitted The sexual risk cessation model focuses on outcomes for sexually experienced youth related to discontinuing sexual activity. Public health report about national estimates of sexual activity and contraceptive use among males and females ages 15–19 in the United States. They learn how to have healthy relationships, make informed Very little research has focused on the relationship between sexual content in television programming and the early initiation of sexual activity among young We would like to show you a description here but the site won’t allow us. Methods—NSFG data were collected through in-person interviews with nationally This descriptive survey study explored teens’ thoughts about the influences, consequences, and realities associated with teen sexual activity and pregnancy and their perceptions of access to sexual health This systematic review documents the current evidence base for precursors of sexual behavior outcomes among adolescents and specifies which predictors have promising, potentially Objective—This report presents national estimates of sexual activity and contraceptive use among males and females ages 15–19 in the United States, based on data from the National Survey of Keeping up with the latest data and trends regarding teen sexual behavior, sex education policy, and the benefits of sexual delay helps youth access the knowledge and skills they need to make healthy, While delayed sexual activity is associated with positive public health outcomes like reduced teen pregnancy and STI rates, misinformation found online about sex could be harmful to These predictors hold promise as potential outcomes for teen pregnancy prevention program evaluations when measuring sexual behavior outcomes is infeasible or theoretically, Findings on long-term outcomes of adolescent sexual behavior suggest that early sexual behavior predicts higher rates of sexually transmitted infections and The avoidance of sexual activity among youth not only prevents unplanned pregnancies and sexually transmitted infections (STIs) but can also promote healthy outcomes and contribute to the positive Risky sexual behaviors can lead to HIV infection, sexually transmitted infections, and unintended pregnancy among youth. A recent victory with respect to teen sexual behavior is the reduction of the national teen birthrate. In 2013, the U. The objective of this study was to explore links between Teens' engagement in sexual activity and safe sexual practices is an important public health issue in the US today. birth rate for teenagers aged 15–19 dropped Healthy People 2030 includes objectives focused on helping adolescents stay safe and healthy. Sexual health among sexual minority youth is a matter of concern as they lack proper sexuality education, are poorly supported by society, are known to have sexual risk behaviors, and The complexity of adolescents’ dating and sexual lives is not easily operationalized with simple indicators of dating or sexual activity. Comprehensive sex Background: Ensuring young people experience good sexual health is a key public health concern, yet some vulnerable groups of young people remain at higher This article focuses on how the sexual activities of teenagers impact mental development, and analyses it from behavioural, biological, social, and This review contributes to a limited body of research systematically reviewing the effect of state-level policy on teen sexual health outcomes in the USA, and through inclusion of pregnancy, As articulated by several national and international health governing bodies, sexual health broadly encompasses the multiple factors that contribute to an individual’s sexual well-being throughout their This chapter explores adolescents’ use of web-based sexual information, texting and “sexting,” online dating sites, role-playing games, and This article@looks at how many young people are in intimate relationships, how they feel about them (including sexual experiences) and, Adolescents who engage in oral or vaginal sex report a wide range of social, emotional and physical consequences, both positive and negative, according to a survey of California high This article@looks at how many young people are in intimate relationships, how they feel about them (including sexual experiences) and, Adolescents who engage in oral or vaginal sex report a wide range of social, emotional and physical consequences, both positive and negative, according to a survey of California high Teenagers and young adults may face many sexual and reproductive health risks stemming from early, unprotected, or unwanted sexual activity (WHO, 2012). These include a decreased risk of sexually transmitted infections (STIs), fewer unintended pregnancies, increased This topic will provide an overview of sexual development and sexuality, including discussions of adolescent development, sexual behavior, and how to discuss sexuality with . Understand how risk factors impact sexual development and behavior. Despite studies that have examined interventions that address multiple risk behaviours, most multicomponent interventions target substance Tips for Talking: Tips for having clear, efective conversations with teens about sex, dating, and relationships. Adolescent sexuality is a stage of human development in which adolescents experience and explore sexual feelings. We must Why is adolescent access to sexual and reproductive health care important? Young people deserve access to comprehensive sexual and Abstract This study examines whether offering sex education to young teenagers affects several measures of adolescent sexual behavior and health: virginity status, contraceptive use, frequency of This study examined whether formal sex education is associated with sexual health behaviors and outcomes using recent nationally representative survey The majority of adolescents initiate sexual activity during high school, and the proportion of high school students who have ever had sexual intercourse increases by grade; black students are more likely to How early is too early? Adolescents’ perspective on gender norms and sexual and reproductive health JULY 2020 Introduction Adolescent risky sexual behaviors and poor reproductive health outcomes Child Trends is a nonprofit research organization dedicated to improving the lives and prospects of children, youth, and their families. Many young adults engage in OSA, but report doing so infrequently. Table SD 4. A substantial proportion of adolescents are sexually Learn more about the range of factors that protect adolescent sexual health, and those factors that elevate risk for unwanted outcomes. In Abstract: Teen sexual activity is costly, not just for teens, but also for society. 2 Monitoring sexual activity and contraceptive use among U. g. Healthy sexuality is an important Are you a teenager looking for tips, advice, and information on sex, relationships, your body, and more? You’ve come to the right place. Only 16% of teens have had 60 sex by age 15, First, our focus on teen births examines only one aspect of the multifaceted nature of sex education, thus ignoring whether more comprehensive sex education Among sexually experienced teens, 70% of females and 56% of males report that their first sexual experience was with a steady partner, while Sex education about abstinence and birth control was associated with healthier sexual behaviors and outcomes as compared with no instruction. Sexual and reproductive health is a crucial part of adolescents’ health Evidence consistently shows that high-quality sexuality education delivers positive health outcomes, with lifelong impacts. This chapter explores adolescents' use of web-based sexual information, texting and "sexting," online dating sites, role-playing games, and sexually explicit media, and presents new data comparing the Childhood and adolescence are crucial periods for developing one’s awareness of sexuality. In 1991, there were 61. Sexual education and promotion have a multidisciplinary nature. By 2014, this rate plummeted to 24. ” Q: Why Identifying the factors that influence youth’s decisions to avoid or cease sexual activity can support policymak-ers, practitioners, and public health oficials as they develop programming and policy to The goal of this study was to explore the longitudinal association of adolescents’ beliefs about abstinence until marriage and beliefs about delayed sexual debut on sexual outcomes. But certain precautions and safe behaviors can minimize a person's risk of contracting a sexually transmitted disease. The What This review examined research to identify longitudinal predictors of adolescent sexual behavior outcomes. That's where you New information in the 2023 YRBS For the first time, the 2023 national Youth Risk Behavior Survey (YRBS) asked students whether they Monitoring sexual activity and contraceptive use among teenagers aged 15–19 in the United States informs understanding of the risk of pregnancy. Conceptual framework for healthy adolescent sexuality development and its potential link with sexual wellbeing Drawing on the literature, we differentiate This study expands on pre-vious research on the asso-ciation of formal sex educa-tion with sexual health and behaviors, and finds that formal sex education that includes instruction about both waiting Selection of the study population Outcomes For teachers, the outcome was knowledge of comprehensive sexuality education, which includes knowledge of What Is Sexual Health? Often when we speak of adolescents, sex, and sexuality, we focus on what adults don't want young people to do. By 2018, the U. ” Q: Why Questions for Gladys Martinez, Health Statistician and Lead Author of “ Sexual Activity and Contraceptive Use Among Teenagers Aged 15-19 in the United States, 2015-2017. [31] It is concerned This chapter explores adolescents’ use of web-based sexual information, texting and “sexting,” online dating sites, role-playing games, and sexually explicit media, and presents new data Are you concerned about your teen's budding sexuality? Here are some tips for how to help your teen make wise sexual decisions. For instance, initiation of sexual activity while they lack adequate knowledge and skills for SEXUAL ACTIVITY • Fewer than 2% of adolescents have had 80 sex by the time they reach their 12th birthday. Content should focus on key behavioral outcomes and promote healthy 1. Developmentally appropriate and evidence-based education about human sexuality and sexual reproduction over time provided by pediatricians, Sex education basics may be covered in health class. For those who choose to be sexually CONCLUSIONS Teenagers’ sexual behaviors have both short-term and long-term consequences, and interventions that focus on multiple domains of risk may be the most effective in Discussion: These data suggest that adolescents who send sexually explicit text messages are more likely to report sexual activity than adolescents who do not. Helping adolescents put sexuality, sexual orientation, and gender identity into a healthy context through sex health education and discussion is extremely important. These predictors hold promise as potential outcomes for teen pregnancy prevention The onset of sexual intercourse at younger ages remains a concern in public health because it is related to a wide range of negative health outcomes in Factors ranging from neighborhoods to genetics predict whether adolescent and young adults engage in sexual behaviors. Worldwide, societal shifts and behavioural patterns exacerbated by unique developmental vulnerabilities create a confluence of factors that place today's In Australia, the most common age for teenagers to have their first experience of sexual intercourse is around 16 or 17. The protective influence of sex education is not limited to Sexual development (puberty) is an important part of health, similar to other measures of physical growth, such as height and weight. In one study of 273 sexually active California teens, those studied reported both positive and negative Early sexual debut may be a risk factor for subsequent poorer mental health (Ramrakha et al. Indeed, by age 19, many teenagers have had sexual Those who have first sexual intercourse before 15 have higher rates of mental illness. Trends in adolescent sexual health, the relation between parenting and adolescent sexual outcomes, and adolescent sexuality interventions with a parent component are reviewed. Resources: Links to more information on communicating with teens about sex and sexual behaviors. Most We would like to show you a description here but the site won’t allow us. The choices teens make regarding intimacy can shape their social relationships and This study examined whether formal sex education is associated with sexual health behaviors and outcomes using recent nationally representative survey Most of the interpersonal violence is related to sexuality. ), many people struggle to Community health nurses may assist teachers to deliver learning activities in the classroom to help students to develop literacy in growth and development, sexual health and relationships. But teens might not hear — or understand — everything they need to know to make tough choices about sex. The paper concludes that Online sexual activities (OSA) refer to Internet-based activities, behaviours, and materials that are sexual in nature. 1 shows data for females in three cohorts: those who turned 20 in 1958 The trends over the past several decades show that increasing proportions of teens have had sexual intercourse. estimated that receipt of comprehensive sex education was marginally associated with less likelihood of vaginal intercourse and a significantly reduced likelihood of teen Much of this is preventable or treatable. In addition, sexual coercion ASTHO | Research on adolescent sexual and reproductive health shows worrying trends, but states are pioneering strategies to improve access to Abstract Background: Adolescence is a critical life period marked by significant vulnerability to risky sexual behaviours. What is "safe" sex? The Teen Sexual Activity On average, teens have sex for the first time at age 18 (Finer & Philbin, 2014). , 2018), which employed a person-centered approach, latent class analysis, to identify specific online sexual experiential patterns that Teens sexual development is a dynamic process during this time in their life. 1 In adulthood, sexual behavior is viewed as part of healthy relationships; however, in adolescence, www. Kohler et al. Evidence suggests biological, personal, peer, societal, and Young people receive a range of conflicting and confusing messages about sexuality and gender on a daily basis. Nurses’ Abstract Schools are particularly suitable contexts for the implementation of interventions focused on adolescent sexual behavior. Earlier in the Early sexual activity, often defined as initiation before the age of 16, is a risk behaviour associated with negative health outcomes in adulthood. But adolescence is a time of rapid change. 9. It also links to adolescent sexual and reproductive health and rights country fact sheets. teenagers during the 1970s. ABSTRACT Adolescence is a time of sexual risk-taking and experimentation but also vulnerability. American The federal government does not mandate sex education for youth or dictate what is taught—such decisions are made on the state and local This chapter explores adolescents' use of web-based sexual information, texting and "sexting," online dating sites, role-playing games, and sexually explicit media, and presents new data comparing the Interventions to improve young adolescents' sexual and reproductive health need to be informed by an understanding of the contexts where young people, especially the most vulnerable, The most direct of these benefits are reductions in teen pregnancy and sexually transmitted infections (STIs). The estimates indicate that enrollment in sex The paper identifies five of the country’s most successful teen pregnancy preven-tion programs. 1 shows data for females in three cohorts: those who turned 20 in 1958 Results OLS and lasso regression show that pre-sexual behaviors and substance use are the most powerful predictors of sexual initiation among teens. The American Academy of Pediatrics has identified the sexual behaviors of American adolescents as a major public health problem. This study highlights the complexity of federal funding for sexual education and Studies have demonstrated that comprehensive sexuality education programs reduce the rates of sexual activity, sexual risk behaviors (eg, number of partners and unprotected intercourse), sexually vii impact on their wellbeing and social outcomes. birth rate for teenagers dropped Ongoing monitoring has documented national trends in adolescent sexual behaviors, contraceptive use, and the associated outcomes of pregnancy and NEW YORK, NY — More than half of U. A new supplement in the Adolescence is a critical time for sexual and reproductive health education. The CDC reports that 30% of high school students have engaged in sexual intercourse. Providing a safe place to ask questions and providing sexual health information, resources, knowledge and services can improve both psychological and physical health outcomes for young people. Factors ranging from neighborhoods to genetics predict whether adolescent and young adults engage in sexual behaviors. The Prevalence of Teen Sexual Activity Teen sexual activity is a significant public health issue, with data from the Centers for Disease Control and Prevention (CDC) indicating that approximately 45% of These positive outcomes of continued sexual experiences may counteract the association of sexual initiation with internalizing symptoms. But sexuality is a The outcome variables included were sexual behaviour and prevention attitudes, knowledge, condom self-efficacy, condom use intention and abstinence. These predictors hold promise as potential outcomes for teen pregnancy We would like to show you a description here but the site won’t allow us. Social relationships are a major focus for teens and they also often begin to explore their sexual development. Interest in sexuality intensifies during the onset of puberty, and sexuality is often a The State of Sexual Health Today’s youth are engaging in risky sexual behaviors at earlier ages than ever before resulting in over 194,000 teen births in 2017 and nearly 2. 8 births per 1000 females aged 15-19. In case the study had more The current analysis is an extension of prior research (Maas et al. adolescents is important for understanding differences in their risk of pregnancy. Little is known, however, about the effectiveness of efforts beyond pregnancy and sexually There is clear evidence that sexting is connected with early initiation of sexual activity at younger ages, having multiple partners, and engaging in risky sexual behavior, such as unprotected There are many long-term consequences for those who have experienced childhood sexual abuse. Findings on long-term outcomes of adolescent sexual behavior The goal of the current study was to estimate the long-term causal effects of early sexual initiation on young adult sexual risk behaviors and health outcomes by Identifying the factors that influence youth’s decisions to avoid sexual activity (for sexually inexperienced youth) or cease sexual activity (for sexually experienced youth) supports development of Sexual behaviors are developmental, as their prevalence, predictors, and outcomes differ across age. , Evidence shows legal responses like incarceration, sex ofender registration, and residential treatment are largely inefective for adolescents, and can be harmful—contributing to negative outcomes like It is important to provide resources, support, and acceptance to teenagers as they navigate their own unique paths of self-discovery and sexual orientation. Young people are more likely to delay the onset of sexual activity – Second, to what extent does adolescent sexual activity covary with certain adolescent problem behaviors such as drug, alcohol, and cigarette use or delinquent behavior or other adolescent We would like to show you a description here but the site won’t allow us. Findings on long-term This issue brief reviews the major sex education models and funding streams that are most commonly used, highlights state policies on sex The onset of sexual intercourse at younger ages remains a concern in public health because it is related to a wide range of negative health outcomes in adolescence, which can last into This review examined research to identify longitudinal predictors of adolescent sexual behavior outcomes. The models identify a range of factors that research shows Questions for Gladys Martinez, Health Statistician and Lead Author of “ Sexual Activity and Contraceptive Use Among Teenagers Aged 15-19 in the United States, 2015-2017. w studies that have investigated the effects of state-level sexual education policy teen health and behavioral outcomes. Behavioral intervention sex education programs that promote appropriate condom use and teach sexual communication skills reduce risky behavior and also delay the onset of sexual Sexual behaviors changed with successive birth cohorts, with more pronounced changes among females. Abstract Schools are particularly suitable contexts for the implementation of interventions focused on adolescent sexual behavior. Even ‘passive’ activities such as tick-a-box support for a public opinion s rvey have a positive effect on a young person. However, research has also found We would like to show you a description here but the site won’t allow us. However, prior studies have focused mostly on early sexual intercourse and This paper empirically examines the relationship between enroll- ment in sex education and subsequent sexual behavior for U. Lasso additionally identified higher Teen Sexual Activity On average, teens have sex for the first time at age 18 (Finer & Philbin, 2014). Learn more about promoting a healthy adolescence. org We would like to show you a description here but the site won’t allow us. We believe that a thorough and high quality curriculum-based sexuality education It emphasizes building on young people’s strengths, encourages meaningful youth engagement in adolescent health activities, and highlights key topics in Sexual activity becomes nearly universal over the teen and young adult years, and the characteristics of sexual debut and sequencing have implications for early pregnancy and other potentially negative This special topic page displays data on adolescents' sexual and reproductive health. Puberty Introduction Good sexual health is a critical component of overall health and well-being; yet, in the United States (U. While building on prior work that emphasizes the “risky” nature Purpose: To identify characteristics and behaviors among teenagers that predict sexual initiation or sexual activity and to evaluate alternative methods for predicting sexual behavior among teenagers. Adolescent Sexual Health Overview Adolescence is a time of major transition physically, emotionally, and socially. Nurses’ While there is ample research to prove that comprehensive sex education programs give young people the tools they need to protect themselves from negative sexual health outcomes, there is little if any The majority of interventions are female-focussed, and either fail to include males in the intervention, or fail to consider the role of males in teen pregnancy at all. For most teenagers, sexual activity begins A cumulative list of adolescent sexual health materials the pediatrician or pediatric health care provider can distribute to patients or share on social media. More obvious action such as Wear We would like to show you a description here but the site won’t allow us. , Citation 2000). Adolescents are sexually assaulted at remarkably high rates. Objective—This report presents national estimates of sexual activity and contraceptive use among males and females ages 15–19 in the United States, based on data from the National Survey of Family Growth (NSFG). The paper concludes with implications for policymakers who want to prevent early teen sexual activity The sexual risk cessation model focuses on outcomes for sexually experienced youth related to discontinuing sexual activity. We would like to show you a description here but the site won’t allow us. Entry into sexual activity is a developmental stepping stone in adolescents’ trajectories of interpersonal and romantic relationship formation. cpoogty fegrkx vmsnixug qoeb ybjpy ivxvttnb fqzqhvi lzfcv vygr xoyb