WorldWideScience

Sample records for jump start teens

  1. School Start Time and Teen Sleep.

    Science.gov (United States)

    Wahlstrom, Kyla L.

    2000-01-01

    Sleep studies have shown that teenagers' internal clocks are incompatible with most high schools' early hours. Research in two Minnesota districts indicates that later school starting times can benefit teens and everyone dealing with them. Student participation in sports and other afterschool activities remained high. (MLH)

  2. Synchronizing Education to Adolescent Biology: "Let Teens Sleep, Start School Later"

    Science.gov (United States)

    Kelley, Paul; Lockley, Steven W.; Foster, Russell G.; Kelley, Jonathan

    2015-01-01

    Arne Duncan, US Secretary of State for Education, tweeted in 2013: "let teens sleep, start school later". This paper examines early starts and their negative consequences in the light of key research in the last 30 years in sleep medicine and circadian neuroscience. An overview of the circadian timing system in adolescence leading to…

  3. Synchronizing Education to Adolescent Biology: "Let Teens Sleep, Start School Later"

    Science.gov (United States)

    Kelley, Paul; Lockley, Steven W.; Foster, Russell G.; Kelley, Jonathan

    2015-01-01

    Arne Duncan, US Secretary of State for Education, tweeted in 2013: "let teens sleep, start school later". This paper examines early starts and their negative consequences in the light of key research in the last 30 years in sleep medicine and circadian neuroscience. An overview of the circadian timing system in adolescence leading to…

  4. Effect of different knee starting angles on intersegmental coordination and performance in vertical jumps.

    Science.gov (United States)

    Gheller, Rodrigo G; Dal Pupo, Juliano; Ache-Dias, Jonathan; Detanico, Daniele; Padulo, Johnny; dos Santos, Saray G

    2015-08-01

    This study aimed to analyze the effect of different knee starting angles on jump performance, kinetic parameters, and intersegmental coupling coordination during a squat jump (SJ) and a countermovement jump (CMJ). Twenty male volleyball and basketball players volunteered to participate in this study. The CMJ was performed with knee flexion at the end of the countermovement phase smaller than 90° (CMJ(90)), and in a preferred position (CMJ(PREF)), while the SJ was performed from a knee angle of 70° (SJ(70)), 90° (SJ(90)), 110° (SJ(110)), and in a preferred position (SJ(PREF)). The best jump performance was observed in jumps that started from a higher squat depth (CMJ(power was observed in the SJ(110) and CMJ(>90). Analysis of continuous relative phase showed that thigh-trunk coupling was more in-phase in the jumps (CMJ and SJ) performed with a higher squat depth, while the leg-thigh coupling was more in-phase in the CMJ(>90) and SJ(PREF). Jumping from a position with knees more flexed seems to be the best strategy to achieve the best performance. Intersegmental coordination and jump performance (CMJ and SJ) were affected by different knee starting angles.

  5. Eleven Tribes Jump START Clean Energy Projects, Summer 2012 (Newsletter)

    Energy Technology Data Exchange (ETDEWEB)

    2012-06-01

    This newsletter describes key activities of the DOE Office of Indian Energy Policy and Programs for Summer 2012. The U.S. Department of Energy Office of Indian Energy Policy and Programs (DOE-IE) has selected 11 Tribes - five in Alaska and six in the contiguous United States - to receive on-the-ground technical support for community-based energy efficiency and renewable energy projects as part of DOE-IE's Strategic Technical Assistance Response Team (START) Program. START finalists were selected based on the clarity of their requests for technical assistance and the ability of START to successfully work with their projects or community. Technical experts from DOE and its National Renewable Energy Laboratory (NREL) will work directly with community-based project teams to analyze local energy issues and assist the Tribes in moving their projects forward. In Alaska, the effort will be bolstered by DOE-IE's partnership with the Denali Commission, which will provide additional assistance and expertise, as well as funding to fuel the Alaska START initiative.

  6. Later Start Time for Teens Improves Grades, Mood, and Safety

    Science.gov (United States)

    Wahlstrom, Kyla L.

    2017-01-01

    A recent study by the University of Minnesota looked at eight high schools across the U.S. that chose later start times, from 8:00 a.m. to 8:55 a.m. The study found significant decreases in absences and tardiness as well as greater academic benefits for schools with the latest start times. Among the 9,395 students in the study, those who slept…

  7. Later Start Time for Teens Improves Grades, Mood, and Safety

    Science.gov (United States)

    Wahlstrom, Kyla L.

    2017-01-01

    A recent study by the University of Minnesota looked at eight high schools across the U.S. that chose later start times, from 8:00 a.m. to 8:55 a.m. The study found significant decreases in absences and tardiness as well as greater academic benefits for schools with the latest start times. Among the 9,395 students in the study, those who slept…

  8. The Effect of an Altitude Training Camp on Swimming Start Time and Loaded Squat Jump Performance.

    Science.gov (United States)

    García-Ramos, Amador; Štirn, Igor; Padial, Paulino; Argüelles-Cienfuegos, Javier; De la Fuente, Blanca; Calderón, Carmen; Bonitch-Góngora, Juan; Tomazin, Katja; Strumbelj, Boro; Strojnik, Vojko; Feriche, Belén

    2016-01-01

    This study evaluated the influence of an altitude training (AT) camp on swimming start time and loaded squat jump performance. To accomplish this goal, 13 international swimmers (8 women, 5 men) were allocated to both the control (Sea Level Training, SLT) and experimental conditions (AT, 2320 m above sea level) that were separated by a one year period. All tests (15 m freestyle swimming start and loaded squat jumps with additional loads of 25%, 50%, 75%, and 100% of swimmers' body weight) were performed before and after a concurrent 3-week strength and endurance training program prescribed by the national coach. Following the SLT camp, significant impairments in swimming start times to 10 (+3.1%) and 15 m (+4.0%) were observed (P camp (-0.89%; P > 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: effectiveness of power-oriented resistance training in the development of explosive actions.

  9. JUMP KINETIC DETERMINANTS OF SPRINT ACCELERATION PERFORMANCE FROM STARTING BLOCKS IN MALE SPRINTERS

    Directory of Open Access Journals (Sweden)

    Peter S. Maulder

    2006-06-01

    Full Text Available The purpose of this research was to identify the jump kinetic determinants of sprint acceleration performance from a block start. Ten male (mean ± SD: age 20 ± 3 years; height 1.82 ± 0.06 m; weight 76.7 ± 7.9 kg; 100 m personal best: 10.87 + 0.36 s {10.37 - 11.42} track sprinters at a national and regional competitive level performed 10 m sprints from a block start. Anthropometric dimensions along with squat jump (SJ, countermovement jump (CMJ, continuous straight legged jump (SLJ, single leg hop for distance, and single leg triple hop for distance measures of power were also tested. Stepwise multiple regression analysis identified CMJ average power (W/kg as a predictor of 10 m sprint performance from a block start (r = 0.79, r2 = 0.63, p<0.01, SEE = 0.04 (s, %SEE = 2.0. Pearson correlation analysis revealed CMJ force and power (r = -0.70 to -0.79; p = 0.011 - 0.035 and SJ power (r = -0.72 to -0.73; p = 0.026 - 0.028 generating capabilities to be strongly related to sprint performance. Further linear regression analysis predicted an increase in CMJ average and peak take-off power of 1 W/kg (3% & 1.5% respectively to both result in a decrease of 0.01 s (0.5% in 10 m sprint performance. Further, an increase in SJ average and peak take-off power of 1 W/kg (3.5% & 1.5% respectively was predicted to result in a 0.01 s (0.5% reduction in 10 m sprint time. The results of this study seem to suggest that the ability to generate power both elastically during a CMJ and concentrically during a SJ to be good indicators of predicting sprint performance over 10 m from a block start

  10. Teens Using E-cigarettes May Be More Likely to Start Smoking Tobacco

    Science.gov (United States)

    ... News Releases News Release Tuesday, August 18, 2015 Teens using e-cigarettes may be more likely to ... to just 9.3 percent of nonusers. “While teen tobacco use has fallen in recent years, this ...

  11. Technical training of qualified athletes , specializing in the high jump with a running start, with additional funds

    Directory of Open Access Journals (Sweden)

    Gusarevich A.V.

    2014-03-01

    Full Text Available Purpose : To improve the process of technical training of qualified athletes, specializing in the high jump with a running start on the basis of additional funds. Material : The study involved 12 athletes qualified I sports category and candidate masters age 18-20 years. Number of attempts varied from 12-15, depending on the degree of fatigue study. Determined the effect of electrical stimulation on muscle groups leading the kinematic and dynamic characteristics of the runway and repulsion, as well as athletic performance. Results : It was established that the integrated use of electrical stimulation affects more effectively to improve the biomechanical characteristics of high jump and effectiveness than using electrical stimulation during takeoff and repulsion separately. Conclusions : On the basis of the experimental data we can recommend the use of complex electrical, as an additional means for improving technical skills and improve performance athletes qualified.

  12. Teen Violence

    Science.gov (United States)

    Teen violence refers to harmful behaviors that can start early and continue into young adulthood. The young person can be a victim, an offender, or a witness to the violence. Violent acts can include Bullying Fighting, including punching, kicking, slapping, ...

  13. Jump-Starting Youth Community Leadership: An Evaluation of a Leadership Development Program for Lesbian, Gay, Bisexual, Transgender & Ally Youth

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Diaz

    2012-03-01

    Full Text Available The GLSEN Jump-Start National Student Leadership Team, a leadership development program for lesbian, gay, bisexual, transgender (LGBT, and ally youth designed to promote direct action community organizing and community engagement. This article examines the benefits of the program for youth’s socio-political development. Data came from a multi-year evaluation that examined changes over time (baseline, immediately post-program, and one-year follow-up in community engagement between a program group (n = 103 and a comparison group of youth (n = 47. Results indicate that the program may support LGBT and ally youth’s socio-political development and have positive implications for their development as community leaders, but these benefits may not be sustained after program completion. Implications for further research and program development for LGBT youth are explored.

  14. Jump Starting Entrepreneurship: How laid-off employees made a career transition

    DEFF Research Database (Denmark)

    Burcharth, Ana Luiza; Smith, Pernille; Frederiksen, Lars

    How do laid-off employees become entrepreneurs after receiving a dream start into self-employment? This question is relevant for policy makers and entrepreneurship researchers alike since it raises the possibility of a reverse entrepreneurial opportunity, in which the chance of becoming an entrep...... persevered in their endeavors and eventually became comfortable with their new career prospects. We discuss the psychological factors that impact career transition after organizational closure and theorize weather they encourage or discourage entrepreneurship....

  15. PeoplePersonality: Chris Clarke - a physicist who studies ice cream Teaching Anecdotes: Annie Jump Cannon Obituary: György Marx 1927-2002 Starting Out: What Katie did next: part 3 Opinions: What is really important?

    Science.gov (United States)

    2003-03-01

    Featuring relationships, personalities, interactions, environments and reputations involved in physics and education PERSONALITY (156) Chris Clarke - a physicist who studies ice cream TEACHING ANECDOTES (157) Annie Jump Cannon OBITUARY (158) György Marx 1927-2002 Steven Chapman STARTING OUT (159) What Katie did next: part 3 Katie Pennicott OPINIONS (160) What is really important? Kerry Parker

  16. Grieving Teen

    Science.gov (United States)

    ... web site can be a good place to advertise the group. What activities work with teens? Teens ... Hospice Foundation. All Rights Reserved. Share this: Twitter Facebook Google Search for: Choosing a Hospice: 16 Questions ...

  17. Computer Forensics JumpStart

    CERN Document Server

    Solomon, Michael G; Tittel, Ed; Broom, Neil; Barrett, Diane

    2011-01-01

    Essential reading for launching a career in computer forensicsInternet crime is on the rise, catapulting the need for computer forensics specialists. This new edition presents you with a completely updated overview of the basic skills that are required as a computer forensics professional. The author team of technology security veterans introduces the latest software and tools that exist and they review the available certifications in this growing segment of IT that can help take your career to a new level. A variety of real-world practices take you behind the scenes to look at the root causes

  18. Helping your teen with depression

    Science.gov (United States)

    Teen depression - helping; Teen depression - talk therapy; Teen depression - medicine ... teen the most. The most effective treatments for depression are: Talk therapy Antidepressant medicines If your teen ...

  19. Choice of jumping strategy in two standard jumps, squat and countermovement jump--effect of training background or inherited preference?

    DEFF Research Database (Denmark)

    Ravn, Susanne; Voigt, M; Simonsen, Erik Bruun

    1999-01-01

    Six male subjects, three professional ballet dancers and three elite volleyball players, performed maximal vertical jumps from 1) a static preparatory position (squat jump), 2) starting with a countermovement (countermovement jump) and 3) a specific jump for ballet and for volleyball, respectively....... The jumps were recorded on highspeed film (500 Hz) combined with registration of ground reaction forces, and net joint moments were calculated by inverse dynamics. The purpose was to investigate the choice of strategy in two standard jumps, squat jump and countermovement jump. The volleyball jump...... was performed with a sequential strategy and the ballet jump was performed with a simultaneous strategy. In the two standard jumps, the choice of strategy was individual and not related to training background. This was additionally confirmed in a test of seven ballet dancers and seven volleyball players....

  20. Teen Smoking

    Science.gov (United States)

    ... also talk with your teen about how tobacco companies try to influence ideas about smoking — such as through advertisements or product placement in movies that create the perception that smoking is glamorous and more prevalent than ...

  1. Teen Gambling

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Teen Gambling Page Content Article Body How can I tell ... son or daughter is having a problem with gambling? Look for the following warning signs: Finding gambling " ...

  2. Jumping on water

    Science.gov (United States)

    Kim, Ho-Young

    2016-11-01

    Water striders can jump on water as high as they can jump on land. Quick jumps allow them to avoid sudden dangers such as predators' attacks, and therefore understanding how they make such a dramatic motion for survival can shed light on the ultimate level of semi-aquatic motility achievable through evolution. However, the mechanism of their vertical jumping from a water surface has eluded hydrodynamic explanations so far. By observing movements of water strider legs and theoretically analyzing their dynamic interactions with deforming liquid-air interface, we have recently found that different species of jumping striders always tune their leg rotation speed with a force just below that required to break the water surface to reach the maximum take-off velocity. Here, we start with discussing the fundamental theories of dynamics of floating and sinking of small objects. The theories then enable us to analyze forces acting on a water strider while it presses down the water surface to fully exploit the capillary force. We further introduce a 68-milligram at-scale robotic insect capable of jumping on water without splash, strikingly similar to the real strider, by utilizing the water surface just as a trampoline.

  3. Jumping Dynamics

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    We propose an alternative paradigm to the conjectured Miransky scaling potentially underlying the physics describing the transition from the conformally broken to the conformally restored phase when tuning certain parameters such as the number of flavors in gauge theories. According to the new...... paradigm the physical scale and henceforth also the massive spectrum of the theory jump at the lower boundary of the conformal window. In particular we propose that a theory can suddenly jump from a Quantum Chromodynamics type spectrum, at the lower boundary of the conformal window, to a conformal one...... without particle interpretation. The jumping scenario, therefore, does not support a near-conformal dynamics of walking type. We will also discuss the impact of jumping dynamics on the construction of models of dynamical electroweak symmetry breaking....

  4. Teen Pregnancy

    Centers for Disease Control (CDC) Podcasts

    2014-04-16

    In this podcast, Dr. Tom Frieden, CDC Director, discusses the issue of teen pregnancy and some strategies to address it.  Created: 4/16/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/16/2014.

  5. Electrostatic charging of jumping droplets

    Science.gov (United States)

    Miljkovic, Nenad; Preston, Daniel J.; Enright, Ryan; Wang, Evelyn N.

    2013-09-01

    With the broad interest in and development of superhydrophobic surfaces for self-cleaning, condensation heat transfer enhancement and anti-icing applications, more detailed insights on droplet interactions on these surfaces have emerged. Specifically, when two droplets coalesce, they can spontaneously jump away from a superhydrophobic surface due to the release of excess surface energy. Here we show that jumping droplets gain a net positive charge that causes them to repel each other mid-flight. We used electric fields to quantify the charge on the droplets and identified the mechanism for the charge accumulation, which is associated with the formation of the electric double layer at the droplet-surface interface. The observation of droplet charge accumulation provides insight into jumping droplet physics as well as processes involving charged liquid droplets. Furthermore, this work is a starting point for more advanced approaches for enhancing jumping droplet surface performance by using external electric fields to control droplet jumping.

  6. Teens and Acne Treatment

    Science.gov (United States)

    ... Pediatrician Ages & Stages Prenatal Baby Toddler Preschool Gradeschool Teen Dating & Sex Fitness Nutrition Driving Safety School Substance Abuse Young Adult Healthy Children > Ages & Stages > Teen > Teens and Acne Treatment Ages & Stages Listen Español ...

  7. Recognizing teen depression

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000648.htm Recognizing teen depression To use the sharing features on this page, ... life. Be Aware of the Risk for Teen Depression Your teen is more at risk for depression ...

  8. Ages and Stages: Teen

    Science.gov (United States)

    ... Spread the Word Shop AAP Find a Pediatrician Ages & Stages Prenatal Baby Toddler Preschool Gradeschool Teen Dating & ... Safety School Substance Abuse Young Adult Healthy Children > Ages & Stages > Teen Teen Article Body Adolescence can be ...

  9. Long Jump

    CERN Document Server

    Dorobantu, V

    2012-01-01

    When the laws of Physics are taken seriously, the sports can benefit in getting better results, as was the case of the high jump in Flop style, so that the athlete sprints diagonally towards the bar,then curve and leap backwards over it. The jumper, in this case, has the center of mass under the bar, fact which allows improvement of the performance.

  10. Dealing with Bullying (For Teens)

    Science.gov (United States)

    ... take a stand, too. Another way to combat bullying is to join your school's anti-violence program or, if your school doesn't have one, to start one of your own. Reviewed by: D'Arcy Lyness, PhD Date reviewed: July 2013 previous ... ON THIS TOPIC Teens Talk About Bullying (Video) Protecting Your Online Identity and Reputation Cyberbullying ...

  11. Teen Top

    Institute of Scientific and Technical Information of China (English)

    盖盖锅锅

    2013-01-01

    8月底发行了迷你四辑的Teen Top,2013已是他们出道的第三年。不忘初心的努力、愉悦的团队氛围……积极向上充满正能量的6人,总是在使自己变得更加“帅气”!

  12. Easy Exercises for Teens

    Science.gov (United States)

    ... Week of Healthy Breakfasts Shyness Easy Exercises for Teens KidsHealth > For Teens > Easy Exercises for Teens A A A en español Ejercicios fáciles para ... not enough.) What more should we do? First, teens should do 60 minutes or more of physical ...

  13. Social Technologies to Jump Start Geoscience Careers

    Science.gov (United States)

    Keane, Christopher; Martinez, Cynthia; Gonzales, Leila

    2010-05-01

    Collaborative and social technologies have been increasingly used to facilitate distributed data collection and observation in science. However, "Web 2.0" and basic social media are seeing limited coordinated use in building student and early-career geoscientists knowledge and understanding of the profession and career for which they have undertaken. The current generation of geology students and early career professionals are used to ready access to myriad of information and interaction opportunities, but they remain largely unaware about the geoscience profession, what the full scope of their opportunities are, and how to reach across institutional and subdisciplinary boundaries to build their own professional network. The American Geological Institute Workforce Program has tracked and supported the human resources of the geosciences since 1952. With the looming retirement of Baby Boomers, increasing demand for quality geoscientists, and a continued modest supply of students entering the geosciences, AGI is working to strengthen the human resource pipeline in the geosciences globally. One aspect of this effort is the GeoConnection Network, which is an integrated set of social networking, media sharing and communication Web 2.0 applications designed to engage students in thinking about careers in the geosciences and enabling them to build their own personal professional network. Developed by the American Geological Institute (AGI), GeoConnection links practicing and prospective geoscientists in an informal setting to share information about the geoscience profession, including student and career opportunities, current events, and future trends in the geosciences. The network includes a Facebook fan page, YouTube Channel, Twitter account and GeoSpectrum blog, with the goal of helping science organizations and departments recruit future talent to the geoscience workforce. On the social-networking platform, Facebook, the GeoConnection page is a forum for students and early career geoscientists to tune in what's going on in the geoscience community, to meet geoscience professionals, and to find innovative career ideas. Early analysis of the page's participants indicates that the network is reaching its intended audience, with more than two-thirds of "fans" participating in the page falling in the 18-34 age range. Twenty-seven percent of these are college-aged, or 18-24 years old. An additional 20% of the page's fans are over age 45, providing students with access to seasoned geoscientists working in a variety of professions. GeoConnection's YouTube Channel includes video resources for students on educational pathways and career choices. Videos on the channel have received more than 100,000 views collectively. In addition, the AGI Workforce program has been an active participant in the YES network, and facilitated the virtual participation of both speakers and attendees for the first YES Congress, held in October 2009 in Beijing. By integrating webinar technologies and other social media, the breadth of attendees and speakers at the Congress was greatly expanded. Challenges with technology represented the minor problem for this effort, but rather human factors required the greatest focus to ensure success. Likewise, the challenge for the GeoConnection Network is not so much technology implementation, but rather remaining responsive and relevant with the ever-changing landscape of online communications. Reports show that participation in social-networking media among young people ages 16-24 has dropped (eg. Istrategy Labs, 2009, Ofcom, 2009) however, internet use among younger generations is high. Geoscience organizations must identify and participate in new online communications trends in order to continue to reach students and young professionals, but also, these individuals must also communicate with geosciences organizations so that the appropriate technologies and venues can be provided to strengthen the interconnect between individuals.

  14. Jump-starting Europe to surpass America

    Index Scriptorium Estoniae

    2003-01-01

    EL-i kahepäevasel tippkohtumisel Brüsselis tegid Euroopa riikide liidrid avalduse majanduse hoogustamisest ja toetasid Euroopa Komisjoni ettepanekut suurendada EL-i investeeringuid transporti, energeetikasse ja teadusesse

  15. Jump-starting Europe to surpass America

    Index Scriptorium Estoniae

    2003-01-01

    EL-i kahepäevasel tippkohtumisel Brüsselis tegid Euroopa riikide liidrid avalduse majanduse hoogustamisest ja toetasid Euroopa Komisjoni ettepanekut suurendada EL-i investeeringuid transporti, energeetikasse ja teadusesse

  16. Teen Childbearing in America's Largest Cities. A KIDS COUNT Working Paper.

    Science.gov (United States)

    O'Hare, William P.

    This paper examines teen births during the period from 1991 to 1996, a period chosen because teen births started to decline in 1991 and 1996 was the most recent data year available. In most cities, the number of births to teens decreased in this period, but in a small number of cities, the number of births to teenagers increased. It is not clear…

  17. Anemia (For Teens)

    Science.gov (United States)

    ... Right Sport for You Healthy School Lunch Planner Anemia KidsHealth > For Teens > Anemia Print A A A ... Getting Enough Iron en español Anemia What Is Anemia? Lots of teens are tired. With all the ...

  18. Teen Suicide and Guns

    Science.gov (United States)

    ... Issues Listen Text Size Email Print Share Teen Suicide and Guns Page Content Article Body Protect Your ... of a passing problem, not the outcome! Teen Suicide—A Big Problem Suicide is one of the ...

  19. Anemia (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Anemia KidsHealth > For Teens > Anemia A A A What's ... Getting Enough Iron en español Anemia What Is Anemia? Lots of teens are tired. With all the ...

  20. Teens in cars.

    NARCIS (Netherlands)

    2014-01-01

    A study from Safe Kids Worldwide, made possible by a grant from the General Motors Foundation, surveyed 1,000 teens to learn why more teens die in motor vehicle crashes than from any other cause of death. The report highlights why teens don’t always buckle up, explores their texting and distraction

  1. Writing, Technology and Teens

    Science.gov (United States)

    Lenhart, Amanda; Arafeh, Sousan; Smith, Aaron

    2008-01-01

    Teenagers' lives are filled with writing. All teens write for school, and 93% of teens say they write for their own pleasure. Most notably, the vast majority of teens have eagerly embraced written communication with their peers as they share messages on their social network pages, in emails and instant messages online, and through fast-paced thumb…

  2. Teens in cars.

    NARCIS (Netherlands)

    2014-01-01

    A study from Safe Kids Worldwide, made possible by a grant from the General Motors Foundation, surveyed 1,000 teens to learn why more teens die in motor vehicle crashes than from any other cause of death. The report highlights why teens don’t always buckle up, explores their texting and distraction

  3. Starting with "I": Personal Essays by Teenagers.

    Science.gov (United States)

    Estepa, Andrea, Ed.; Kay, Philip, Ed.

    In personal essays, teenagers express their views on serious subjects like violence, racism, and teen parenting, and discuss common teen experiences like dating, getting a job, and starting college. This collection contains the following: (1) "Brotherly Love" (Jessica Vicuna); (2) "How To Survive Shopping with Mom" (Chris Kanarick); (3) "A…

  4. Jump Horse Safety: Reconciling Public Debate and Australian Thoroughbred Jump Racing Data, 2012-2014.

    Science.gov (United States)

    Ruse, Karen; Davison, Aidan; Bridle, Kerry

    2015-10-22

    Thoroughbred jump racing sits in the spotlight of contemporary welfare and ethical debates about horse racing. In Australia, jump racing comprises hurdle and steeplechase races and has ceased in all but two states, Victoria and South Australia. This paper documents the size, geography, composition, and dynamics of Australian jump racing for the 2012, 2013, and 2014 seasons with a focus on debate about risks to horses. We found that the majority of Australian jump racing is regional, based in Victoria, and involves a small group of experienced trainers and jockeys. Australian jump horses are on average 6.4 years of age. The jump career of the majority of horses involves participating in three or less hurdle races and over one season. Almost one quarter of Australian jump horses race only once. There were ten horse fatalities in races over the study period, with an overall fatality rate of 5.1 fatalities per 1000 horses starting in a jump race (0.51%). There was significant disparity between the fatality rate for hurdles, 0.75 fatalities per 1000 starts (0.075%) and steeplechases, 14 fatalities per 1000 starts (1.4%). Safety initiatives introduced by regulators in 2010 appear to have significantly decreased risks to horses in hurdles but have had little or no effect in steeplechases. Our discussion considers these Animals 2015, 5 1073 data in light of public controversy, political debate, and industry regulation related to jump horse safety.

  5. Jump Horse Safety: Reconciling Public Debate and Australian Thoroughbred Jump Racing Data, 2012–2014

    Directory of Open Access Journals (Sweden)

    Karen Ruse

    2015-10-01

    Full Text Available Thoroughbred jump racing sits in the spotlight of contemporary welfare and ethical debates about horse racing. In Australia, jump racing comprises hurdle and steeplechase races and has ceased in all but two states, Victoria and South Australia. This paper documents the size, geography, composition, and dynamics of Australian jump racing for the 2012, 2013, and 2014 seasons with a focus on debate about risks to horses. We found that the majority of Australian jump racing is regional, based in Victoria, and involves a small group of experienced trainers and jockeys. Australian jump horses are on average 6.4 years of age. The jump career of the majority of horses involves participating in three or less hurdle races and over one season. Almost one quarter of Australian jump horses race only once. There were ten horse fatalities in races over the study period, with an overall fatality rate of 5.1 fatalities per 1000 horses starting in a jump race (0.51%. There was significant disparity between the fatality rate for hurdles, 0.75 fatalities per 1000 starts (0.075% and steeplechases, 14 fatalities per 1000 starts (1.4%. Safety initiatives introduced by regulators in 2010 appear to have significantly decreased risks to horses in hurdles but have had little or no effect in steeplechases. Our discussion considers these Animals 2015, 5 1073 data in light of public controversy, political debate, and industry regulation related to jump horse safety.

  6. The Teen Science Café Network

    Science.gov (United States)

    Hall, M.; Mayhew, M. A.

    2013-12-01

    The 'Teen Cafè' phenomenon grew out of an NSF-funded experiment to bring the Cafè Scientifique model for engagement of the public with science and scientists to high school teenagers. Cafè Scientifique New Mexico (cafènm.org), now in its seventh year, has proven highly popular with high school teens for much the same reason as for adult Cafè programs: the blend of socializing in an attractive venue and interaction with a scientist on an interesting science topic. Teen Cafés also include exploration of the topic with hands-on activities. The success of the model has led to the creation of the national Teen Science Cafè Network (teensciencecafe.org. This first year of the new program, four 'Founding Members' of the Network-- in Florida, Colorado, North Carolina, and the St. Louis, Missouri region--started up Teen Cafè programs. Each applied the model with a unique flair appropriate to local institutions and demographics. Each Member in the Network runs Cafès in multiple local venues. We are now gearing up for our second year, and the Network is growing. Our Teen Cafè topics have covered a very wide range, from belly-button biodiversity to cyber-security to patterns of mega-earthquakes to a day in the life of a teen dolphin to corals on acid to emergency room medicine to alternative fuel cars. Presenters have come from a great variety of local institutions. Though they are popular with teens because they are fun and interesting, our evaluations have demonstrated that the programs are having a significant impact on participating teens' understanding of the nature of science, the work that scientists do, and the importance of science to their daily lives. We are also having success in training scientists to communicate effectively with this public audience. Presenters report strong satisfaction with their resulting quality of science communication. A surprising number have reported that their experience with the program has led them to think in a new way about

  7. Teen pregnancy: an update.

    Science.gov (United States)

    McCracken, Katherine A; Loveless, Meredith

    2014-10-01

    To provide clinicians with a review of recent research and clinically applicable tools regarding teen pregnancy. Teen pregnancy rates have declined but still remain a significant problem in the USA. Teen pregnancy prevention was identified by Centers for Disease Control and Prevention as one of its top six priorities, which is increasing research and intervention data. Long-acting contraceptive methods are acceptable to teens and have been shown to reduce teen birth rates. Pregnant teens need special attention to counseling on pregnancy options and reducing risk during pregnancy with regular prenatal care. Postpartum teens should be encouraged and supported to breastfeed, monitored for depression, and have access to reliable contraception to avoid repeat undesired pregnancy. This review highlights important issues for all providers caring for female adolescents and those who may encounter teen pregnancy. Foremost prevention of teen pregnancy by comprehensive sexual education and access to contraception is the priority. Educating patients and healthcare providers about safety and efficacy of long-acting reversible contraception is a good step to reducing undesired teen pregnancies. Rates of postpartum depression are greater in adolescents than in adults, and adolescent mothers need to be screened and monitored for depression. Strategies to avoid another undesired pregnancy shortly after delivery should be implemented.

  8. Helping Teens Resist Sexual Pressure

    Science.gov (United States)

    ... Size Email Print Share Helping Teens Resist Sexual Pressure Page Content Article Body Teens are more likely ... time they had intercourse. Helping Teens Resist Sexual Pressure “The pressure on teenagers to have sex is ...

  9. Talking to Kids and Teens

    Science.gov (United States)

    ... Back to top Ways to help children and teens cope Offer comfort and support Provide opportunities for ... Watch a movie Keep a journal together Kids & Teens Web section To help children and teens learn ...

  10. Jump Horse Safety: Reconciling Public Debate and Australian Thoroughbred Jump Racing Data, 2012–2014

    Science.gov (United States)

    Ruse, Karen; Davison, Aidan; Bridle, Kerry

    2015-01-01

    Simple Summary This paper documents the dynamics of Australian thoroughbred jump racing in the 2012, 2013, and 2014 seasons with the aim of informing debate about risks to horses and the future of this activity. We conclude that the safety of Australian jump racing has improved in recent years but that steeplechases are considerably riskier for horses than hurdle races. Abstract Thoroughbred jump racing sits in the spotlight of contemporary welfare and ethical debates about horse racing. In Australia, jump racing comprises hurdle and steeplechase races and has ceased in all but two states, Victoria and South Australia. This paper documents the size, geography, composition, and dynamics of Australian jump racing for the 2012, 2013, and 2014 seasons with a focus on debate about risks to horses. We found that the majority of Australian jump racing is regional, based in Victoria, and involves a small group of experienced trainers and jockeys. Australian jump horses are on average 6.4 years of age. The jump career of the majority of horses involves participating in three or less hurdle races and over one season. Almost one quarter of Australian jump horses race only once. There were ten horse fatalities in races over the study period, with an overall fatality rate of 5.1 fatalities per 1000 horses starting in a jump race (0.51%). There was significant disparity between the fatality rate for hurdles, 0.75 fatalities per 1000 starts (0.075%) and steeplechases, 14 fatalities per 1000 starts (1.4%). Safety initiatives introduced by regulators in 2010 appear to have significantly decreased risks to horses in hurdles but have had little or no effect in steeplechases. Our discussion considers these data in light of public controversy, political debate, and industry regulation related to jump horse safety. PMID:26506396

  11. Youth and Teens Page

    Science.gov (United States)

    ... Call NRS Publications Free Promotional Materials Runaway Statistics Crisis Hotline & Online Service Statistics Third Party Statistics NRS Publications Homeless Teen and Runaway Youth Research from NRS Resources & ...

  12. Risk, Jumps, and Diversification

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Law, Tzuo Hann; Tauchen, George

    We test for price discontinuities, or jumps, in a panel of high-frequency intraday returns for forty large-cap stocks and an equiweighted index from these same stocks. Jumps are naturally classified into two types: common and idiosyncratic. Common jumps affect all stocks, albeit to varying degree...

  13. Jumping in Arithmetic

    NARCIS (Netherlands)

    Visser, Albert

    2014-01-01

    In this paper we study a new relation between sentences: the jump relation. The idea of the jump relation is based on an analysis of Feferman's Theorem that the inconsistency of a theory U is interpretable over U. The jump relation is based on a converse of Feferman's Theorem: if a sentence is inter

  14. Effect of early training on the jumping technique of horses.

    Science.gov (United States)

    Santamaría, Susana; Bobbert, Maarten F; Back, Willem; Barneveld, Ab; van Weeren, P Rene

    2005-03-01

    To investigate the effects of early training for jumping by comparing the jumping technique of horses that had received early training with that of horses raised conventionally. 40 Dutch Warmblood horses. The horses were analyzed kinematically during free jumping at 6 months of age. Subsequently, they were allocated into a control group that was raised conventionally and an experimental group that received 30 months of early training starting at 6 months of age. At 4 years of age, after a period of rest in pasture and a short period of training with a rider, both groups were analyzed kinematically during free jumping. Subsequently, both groups started a 1-year intensive training for jumping, and at 5 years of age, they were again analyzed kinematically during free jumping. In addition, the horses competed in a puissance competition to test maximal performance. Whereas there were no differences in jumping technique between experimental and control horses at 6 months of age, at 4 years, the experimental horses jumped in a more effective manner than the control horses; they raised their center of gravity less yet cleared more fences successfully than the control horses. However, at 5 years of age, these differences were not detected. Furthermore, the experimental horses did not perform better than the control horses in the puissance competition. Specific training for jumping of horses at an early age is unnecessary because the effects on jumping technique and jumping capacity are not permanent.

  15. Teen Pregnancy and Childbearing

    Science.gov (United States)

    ... Between 1991 and 2015, the teen birth rate decreased by more than half in the United States ( ... 1] Despite this decline, the U.S. teen birth rate is still higher than that of many ... prevention programs , expanding access to Medicaid family planning ...

  16. Types of Cancer Teens Get

    Science.gov (United States)

    ... Week of Healthy Breakfasts Shyness Types of Cancer Teens Get KidsHealth > For Teens > Types of Cancer Teens Get A A A What's in this article? ... que padecen los adolescentes Cancer is rare in teens. Certain diseases like breast cancer usually affect adult ...

  17. Teen Mothers' Mental Health.

    Science.gov (United States)

    SmithBattle, Lee; Freed, Patricia

    2016-01-01

    Psychological distress is common in teen mothers. High rates of distress are attributed to teen mothers' childhood adversities and the challenges of parenting in the context of chronic stress, cumulative disadvantage, and limited social support. We describe the prevalence of psychological distress in teen mothers; what is known about its origins and impact on mothers and children; factors that promote teen mothers' mental health and resilience; and the many barriers that make it difficult to obtain traditional mental healthcare. We also briefly review the few studies that test interventions to improve teen mothers' mental health. Because barriers to traditional mental health treatment are ubiquitous and difficult to remedy, the second article in this two-part series calls for nurses in healthcare settings, schools, and home visiting programs to screen pregnant and parenting teens for adverse childhood experiences and psychological distress, and to integrate strength-based and trauma-based principles into their practice. Creating a supportive setting where past traumas and psychological distress are addressed with skill and sensitivity builds upon teen mothers' strengths and their aspirations to be the best parents they can be. These approaches facilitate the long-term health and development of mother and child.

  18. Steerable Miniature Jumping Robot

    OpenAIRE

    Kovac, Mirko; Schlegel, Manuel; Zufferey, Jean-Christophe; Floreano, Dario

    2010-01-01

    Jumping is used in nature by many small animals to locomote in cluttered environments or in rough terrain. It offers small systems the benefit of overcoming relatively large obstacles at a low energetic cost. In order to be able to perform repetitive jumps in a given direction, it is important to be able to upright after landing, steer and jump again. In this article, we review and evaluate the uprighting and steering principles of existing jumping robots and present a novel spherical robot w...

  19. Adolescent perceptions of teen births.

    Science.gov (United States)

    Herrman, Judith W

    2008-01-01

    To investigate teens' perceptions of the costs and rewards of teen births, potential interventions to prevent teen pregnancy, and the presence of someone with whom teens could discuss sexuality. Seventeen focus groups were conducted to solicit individual views, group interactions, and shared meanings. Purposive methods accessed a sample of teens considered at risk of teen pregnancy based on their membership in selected community service and teen groups. Teen parents and nonparents (n = 120), from 12 to 19 years of age, were asked about their lives and stresses and the costs and rewards related to teen births. This study yielded rich data about the consequences of teen births. Data were organized in the domains of Impact on relationships, Impact on vocation, and Impact on self. The data reflected the cost and reward themes in each domain. Though teens believed that there were positives of teen births, early childbearing was considered "hard" in many aspects. These perceptions may be used to guide programs, policies, messages, and curricula with the intent to prevent teen pregnancy. These initiatives may be more effective if informed by teens and guided by their perceptions.

  20. Parents, Teens, and Reading: A Winning Combination.

    Science.gov (United States)

    International Reading Association, Newark, DE.

    Noting that surveys show that teens still value their parents' opinions, this booklet contains many helpful suggestions designed to get parents and their teens reading and talking together. Sections of the booklet are: "Where To Begin? Know Your Teen"; "How Can I Get My Teen To Read?"; "Give Your Teen Reasons To Read"; "Teens, Technology, and…

  1. Smoking (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Smoking KidsHealth > For Teens > Smoking A A A What's ... thing as a "safe" nicotine product. continue How Smoking Affects Your Health There are no physical reasons ...

  2. Bipolar Disorder (For Teens)

    Science.gov (United States)

    ... making a few lifestyle changes, such as reducing stress, eating well, and getting enough sleep and exercise can help someone who is living with the condition. And many teens find it helps to join a support network ...

  3. Turner Syndrome (For Teens)

    Science.gov (United States)

    ... 1 • 2 • 3 For Teens For Kids For Parents MORE ON THIS TOPIC Dealing With a Health Condition Delayed Puberty How Can I Improve My Self-Esteem? Body Image and Self-Esteem Thyroid Disease Contact ...

  4. Bipolar Disorder (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Bipolar Disorder KidsHealth > For Teens > Bipolar Disorder A A ... Bipolar Disorder en español Trastorno bipolar What Is Bipolar Disorder? Bipolar disorders are one of several medical ...

  5. Hodgkin Lymphoma (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Hodgkin Lymphoma KidsHealth > For Teens > Hodgkin Lymphoma Print A ... to check for disease, including lymphoma. What Is Hodgkin Lymphoma? Hodgkin lymphoma is a type of cancer ...

  6. Marijuana and Teens

    Science.gov (United States)

    ... Families Guide - Search Spanish Facts for Families Guide Marijuana and Teens No. 106; Updated July 2013 Many teenagers experiment with marijuana. Friends, peer pressure, and portrayal of marijuana in ...

  7. Cerebral Palsy (For Teens)

    Science.gov (United States)

    ... Right Sport for You Healthy School Lunch Planner Cerebral Palsy KidsHealth > For Teens > Cerebral Palsy Print A A ... do just what everyone else does. What Is Cerebral Palsy? Cerebral palsy (CP) is a disorder of the ...

  8. Thyroid Disease and Teens

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness Thyroid Disease KidsHealth > For Teens > Thyroid Disease Print A ... other parts of your body. continue What Is Thyroid Disease? Thyroid disease occurs when the thyroid gland ...

  9. Thyroid Disease and Teens

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Thyroid Disease KidsHealth > For Teens > Thyroid Disease A A ... other parts of your body. continue What Is Thyroid Disease? Thyroid disease occurs when the thyroid gland ...

  10. Sinusitis (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Sinusitis KidsHealth > For Teens > Sinusitis Print A A A ... times, but it's usually not severe. What Is Sinusitis? Sinusitis is the medical term for inflammation (irritation ...

  11. Lactose Intolerance (For Teens)

    Science.gov (United States)

    ... salad dressings, mixes for cakes and cookies, and coffee creamers. Be aware of certain words that might mean the food has ... TOPIC About Recipes for Teens With Lactose Intolerance Calcium Nutrition & Fitness ...

  12. Peritonsillar Abscess (For Teens)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Peritonsillar Abscess KidsHealth > For Teens > Peritonsillar Abscess A A A ... en español Abscesos periamigdalinos What Is a Peritonsillar Abscess? A peritonsillar abscess is an area of pus- ...

  13. Date Rape (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Date Rape KidsHealth > For Teens > Date Rape A A ... Rape en español Violaciones durante citas What Is Date Rape? When people think of rape , they might ...

  14. Feeding Your Teen Vegetarian

    Science.gov (United States)

    ... Kidney Disease Food Allergies Healthy Aging Fertility and Reproduction Top Articles High-and Moderate-Potassium Foods Kidney ... why a teen stops eating some or all animal-based foods, parents play an important role in ...

  15. Optimal Ski Jump

    Science.gov (United States)

    Rebilas, Krzysztof

    2013-01-01

    Consider a skier who goes down a takeoff ramp, attains a speed "V", and jumps, attempting to land as far as possible down the hill below (Fig. 1). At the moment of takeoff the angle between the skier's velocity and the horizontal is [alpha]. What is the optimal angle [alpha] that makes the jump the longest possible for the fixed magnitude of the…

  16. Jumping Good Fun

    Science.gov (United States)

    Nye, Susan B.

    2010-01-01

    Jumping rope is an activity that can be fun and enjoyable for all students. It requires minimal activity space, can be performed individually or in small groups, and is an inexpensive way to engage students in a lifelong physical activity. Jumping rope is commonly used by coaches and athletes for training purposes to improve aerobic endurance,…

  17. Jumping Good Fun

    Science.gov (United States)

    Nye, Susan B.

    2010-01-01

    Jumping rope is an activity that can be fun and enjoyable for all students. It requires minimal activity space, can be performed individually or in small groups, and is an inexpensive way to engage students in a lifelong physical activity. Jumping rope is commonly used by coaches and athletes for training purposes to improve aerobic endurance,…

  18. Estimation of Jump Tails

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Todorov, Victor

    We propose a new and flexible non-parametric framework for estimating the jump tails of Itô semimartingale processes. The approach is based on a relatively simple-to-implement set of estimating equations associated with the compensator for the jump measure, or its "intensity", that only utilizes ...

  19. Teen Sleep: Why Is Your Teen So Tired?

    Science.gov (United States)

    ... teens need about eight to 10 hours of sleep a night — and sometimes more — to maintain optimal daytime alertness. But few teens actually get that much sleep regularly, thanks to factors such as part-time ...

  20. Preschool-aged children's jumps: imitation performances.

    Science.gov (United States)

    Labiadh, Lazhar; Ramanantsoa, Marie-Martine; Golomer, Eveline

    2010-04-01

    Imitative behavior underlaid by perception and action links during children's development in complex locomotor skills has been the object of relatively few studies. In order to explore children's motor coordination modes, 130 children divided into five age groups from 3.5 to 7.5 years were instructed to imitate jumping tasks in spontaneous motor situation and in various imitative contexts by an adult providing verbal orders and gestural demonstrations. Their conformity to the model, stability and variability scores were coded from a video analysis when they performed jumps with obstacles. To evaluate their postural-motor control level, the durations of the preparatory phase and jumping flights were also timed. Results showed that all age groups generated the demonstrator's goal but not necessarily the same coordination modes of jumping. In imitation with temporal proximity, the model helped the youngest age groups to adopt his coordination modes and stabilized only the oldest age groups' performances starting from 5.5 years old, without effect on learning imitation. Differences between the youngest and oldest children in the jump duration suggested that the reproduction of a complex motor activity such as jumping with a one foot take-off would require resolution and adjustment of main postural stability.

  1. Quantum Walk with Jumps

    CERN Document Server

    Lavička, H; Kiss, T; Lutz, E; Jex, I

    2011-01-01

    We analyze a special class of 1-D quantum walks (QWs) realized using optical multi-ports. We assume non-perfect multi-ports showing errors in the connectivity, i.e. with a small probability the multi- ports can connect not to their nearest neighbor but to another multi-port at a fixed distance - we call this a jump. We study two cases of QW with jumps where multiple displacements can emerge at one timestep. The first case assumes time-correlated jumps (static disorder). In the second case, we choose the positions of jumps randomly in time (dynamic disorder). The probability distributions of position of the QW walker in both instances differ significantly: dynamic disorder leads to a Gaussian-like distribution, while for static disorder we find two distinct behaviors depending on the parity of jump size. In the case of even-sized jumps, the distribution exhibits a three-peak profile around the position of the initial excitation, whereas the probability distribution in the odd case follows a Laplace-like discre...

  2. An Update on Teen Pregnancy.

    Science.gov (United States)

    Ahern, Nancy R; Bramlett, Traci

    2016-02-01

    After years of high teen birth rates, there is currently a decline in U.S. pregnancy and birth rates among teens. Nevertheless, these rates continue to be higher than those of most global counterparts, and psychosocial and physical adversities still occur for pregnant teens and their children. The declining birth rates may be due to teens making better choices about contraceptive use and sexual behaviors. Psychiatric-mental health nurses are in key positions to enhance pregnancy prevention for teens. [Journal of Psychosocial Nursing and Mental Health Services, 54(2), 25-28.].

  3. Teens, technology, and health care.

    Science.gov (United States)

    Leanza, Francesco; Hauser, Diane

    2014-09-01

    Teens are avid users of new technologies and social media. Nearly 95% of US adolescents are online at least occasionally. Health care professionals and organizations that work with teens should identify online health information that is both accurate and teen friendly. Early studies indicate that some of the new health technology tools are acceptable to teens, particularly texting, computer-based psychosocial screening, and online interventions. Technology is being used to provide sexual health education, medication reminders for contraception, and information on locally available health care services. This article reviews early and emerging studies of technology use to promote teen health. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Peritonsillar Abscess (For Teens)

    Science.gov (United States)

    ... The earlier a doctor diagnoses it, the easier treatment is likely to be. Reviewed by: Patricia Solo-Josephson, MD Date reviewed: June 2017 For Teens For Kids For Parents MORE ON THIS TOPIC Tonsils and Tonsillectomies Tonsillitis Strep Throat How Can I Quit Smoking? Gum ...

  5. Teen Pregnancy Prevention.

    OpenAIRE

    Rebecca A. Maynard; Amy Johnson

    2001-01-01

    Reports on the national evaluation of Title V abstinence education programs, focusing on 1) the need for scientifically rigorous research to improve future policies and practices, 2) ways in which federal support for abstinence education has changed local approaches to reducing teen sexual activity, and 3) what the national evaluation will contribute to the knowledge base.

  6. Teen Pregnancy Prevention

    OpenAIRE

    Melissa Schettini Kearney

    2001-01-01

    Reports on the national evaluation of Title V abstinence education programs, focusing on 1) the need for scientifically rigorous research to improve future policies and practices, 2) ways in which federal support for abstinence education has changed local approaches to reducing teen sexual activity, and 3) what the national evaluation will contribute to the knowledge base.

  7. The Teening of Childhood.

    Science.gov (United States)

    Hymowitz, Kay S.

    2000-01-01

    The market and advertising media aimed at children has skyrocketed in recent years. Many new products targeting 8-12-year-olds appeal to their sense of teen fashion, image consciousness, and independence from adults. Describes the development of this market aimed at early adolescents and how it is changing childhood as Americans have known it. (SM)

  8. Date Rape (For Teens)

    Science.gov (United States)

    ... sure, let the other person know. Don't let peer pressure push you into something you don't want to do. "Everybody's doing it" is a myth. Most teens are not having sex, even if they are talking about it. Go out with a group of friends and watch ...

  9. Sugary Drink Warnings Hit Home with Teens

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160860.html Sugary Drink Warnings Hit Home With Teens Fewer choose sweetened ... Health warning labels can steer teens away from sugary drinks, a new study suggests. "The average teen in ...

  10. Teaching Teens To Use Condoms Faithfully

    Science.gov (United States)

    ... Pediatrician Ages & Stages Prenatal Baby Toddler Preschool Gradeschool Teen Dating & Sex Fitness Nutrition Driving Safety School Substance Abuse Young Adult Healthy Children > Ages & Stages > Teen > Dating & Sex > Teaching Teens To Use Condoms Faithfully Ages & Stages ...

  11. CDC Vital Signs: Preventing Repeat Teen Births

    Science.gov (United States)

    ... file Error processing SSI file Preventing Repeat Teen Births Recommend on Facebook Tweet Share Compartir On this ... Too many teens, ages 15–19, have repeat births. Nearly 1 in 5 births to teens, ages ...

  12. Performance-Enhancing Drugs and Teen Athletes

    Science.gov (United States)

    Healthy Lifestyle Tween and teen health Performance-enhancing drugs can be tempting for teen athletes. Understand the warning signs and what you can do to keep your teen from using shortcuts to improve athletic performance. By Mayo ...

  13. What do adolescents think about teen parenting?

    Science.gov (United States)

    Herrman, Judith W; Waterhouse, Julie K

    2011-06-01

    Unexpected increases in the teen birth rates have stimulated a renewed focus on the prevention of teen pregnancy. Although many adults believe there are certain costs associated with teen parenting, the attitudes of teens toward the parenting experience are not known. The purpose of this descriptive study was to determine teens' thoughts on how their lives would change if they experienced a teen birth in the areas of relationships, vocation, and life impacts. The Thoughts on Teen Parenting Survey (TTPS), designed to measure demographic variables and perspectives on the costs and rewards of teen parenting, was administered to 695 high school students. The survey yielded a composite score, subscale scores, and aggregate data measuring teen thoughts on the consequences of the teen parenting experience. Findings may be used to identify teens at risk for pregnancy, develop interventions, and evaluate prevention strategies based on the insights of teens.

  14. Spinning hydraulic jump

    Science.gov (United States)

    Abderrahmane, Hamid; Kasimov, Aslan

    2013-11-01

    We report an experimental observation of a new symmetry breaking of circular hydraulic jump into a self-organized structure that consists of a spinning polygonal jump and logarithmic-spiral waves of fluid elevation downstream. The waves are strikingly similar to spiral density waves in galaxies. The fluid flow exhibits counterparts of salient morphological features of galactic flows, in particular the outflow from the center, jets, circum-nuclear rings, gas inflows toward the galactic center, and vortices. The hydrodynamic instability revealed here may have a counterpart that plays a role in the formation and sustainability of spiral arms in galaxies.

  15. Teen Ambassador Leadership Kit (TALK

    Directory of Open Access Journals (Sweden)

    Donna R. Gillespie

    2012-12-01

    Full Text Available Teen Ambassador Leadership Kit, (TALK, is an annual weekend retreat designed for teens interested in promoting and marketing 4-H in their communities. TALK organizers felt teens would benefit from an intensive weekend retreat focused on communication. TALK produces a network of educated and excited 4-H teens that are available to help with 4-H promotion and marketing. Participants arrive on Friday evening for team building activities, on Saturday they participate in one of the workshops offered and on Sunday morning each workshop group has the opportunity to share their completed projects and what they learned. At the conclusion of the retreat, teens are designated "County 4-H Ambassadors" and certificates of completion, professional business cards and polo shirts are presented. The TALK teen participants return home to share what they learned with their local county 4-H staff and help promote and market 4-H in their communities.

  16. Teen Risk-Taking: Promising Prevention Programs and Approaches.

    Science.gov (United States)

    Eisen, Marvin; Pallitto, Christina; Bradner, Carolyn; Bolshun, Natalya

    This guidebook explores some of the practical issues associated with finding, choosing, and starting potentially effective prevention programs for at-risk preteens and teens. The guidebook is based on a study of 51 intervention programs that identified elements and delivery mechanisms that were associated with their effectiveness. A closer look at…

  17. Getting Started with Processing

    CERN Document Server

    Reas, Casey

    2010-01-01

    Learn computer programming the easy way with Processing, a simple language that lets you use code to create drawings, animation, and interactive graphics. Programming courses usually start with theory, but this book lets you jump right into creative and fun projects. It's ideal for anyone who wants to learn basic programming, and serves as a simple introduction to graphics for people with some programming skills. Written by the founders of Processing, this book takes you through the learning process one step at a time to help you grasp core programming concepts. You'll learn how to sketch wi

  18. Technology and teen drivers.

    Science.gov (United States)

    Lee, John D

    2007-01-01

    The rapid evolution of computing, communication, and sensor technology is likely to affect young drivers more than others. The distraction potential of infotainment technology stresses the same vulnerabilities that already lead young drivers to crash more frequently than other drivers. Cell phones, text messaging, MP3 players, and other nomadic devices all present a threat because young drivers may lack the spare attentional capacity for vehicle control and the ability to anticipate and manage hazards. Moreover, young drivers are likely to be the first and most aggressive users of new technology. Fortunately, emerging technology can also support safe driving. Electronic stability control, collision avoidance systems, intelligent speed adaptation, and vehicle tracking systems can all help mitigate the threats to young drivers. However, technology alone is unlikely to make young drivers safer. One promising approach to tailoring technology to teen drivers is to extend proven methods for enhancing young driver safety. The success of graduated drivers license programs (GDL) and the impressive safety benefit of supervised driving suggest ways of tailoring technology to the needs of young drivers. To anticipate the effects of technology on teen driving it may be useful to draw an analogy between the effects of passengers and the effects of technology. Technology can act as a teen passenger and undermine safety or it can act as an adult passenger and enhance safety. Rapidly developing technology may have particularly large effects on teen drivers. To maximize the positive effects and minimize the negative effects will require a broad range of industries to work together. Ideally, vehicle manufacturers would work with infotainment providers, insurance companies, and policy makers to craft new technologies so that they accommodate the needs of young drivers. Without such collaboration young drivers will face even greater challenges to their safety as new technologies emerge.

  19. Smells Like Teen Spirit: Evaluating a Midwestern Teen Court

    Science.gov (United States)

    Norris, Michael; Twill, Sarah; Kim, Chigon

    2011-01-01

    Teen courts have grown rapidly in the United States despite little evidence of their effectiveness. A survival analysis of 635 teen court and 186 regular diversion participants showed no significant differences in recidivism, although program completers were half as likely to reoffend as noncompleters. Older offenders survived significantly better…

  20. Smells Like Teen Spirit: Evaluating a Midwestern Teen Court

    Science.gov (United States)

    Norris, Michael; Twill, Sarah; Kim, Chigon

    2011-01-01

    Teen courts have grown rapidly in the United States despite little evidence of their effectiveness. A survival analysis of 635 teen court and 186 regular diversion participants showed no significant differences in recidivism, although program completers were half as likely to reoffend as noncompleters. Older offenders survived significantly better…

  1. Parents, Teens, and Online Privacy

    Science.gov (United States)

    Madden, Mary; Cortesi, Sandra; Gasser, Urs; Lenhart, Amanda; Duggan, Maeve

    2012-01-01

    Most parents of teenagers are concerned about what their teenage children do online and how their behavior could be monitored by others. Some parents are taking steps to observe, discuss, and check up on their children's digital footprints. A new survey of 802 parents and their teens shows that: (1) 81% of parents of online teens say they are…

  2. College Students' Positivity toward Teen Mothers

    Science.gov (United States)

    Eshbaugh, Elaine M.

    2011-01-01

    Although teen pregnancy and parenthood are more visible in society than in the past, teen mothers are often stereotyped and stigmatized. The study examined positivity toward teen mothers among college students (N = 316) at a midwestern university. Although students responded positively to some items regarding teen mothers, other statements showed…

  3. Parent-teen communication about sex in urban Thai families.

    Science.gov (United States)

    Rhucharoenpornpanich, Orratai; Chamratrithirong, Aphichat; Fongkaew, Warunee; Miller, Brenda A; Cupp, Pamela K; Rosati, Michael J; Byrnes, Hilary F; Atwood, Katharine A; Chookhare, Warunee

    2012-01-01

    This study describes sexual communication among Thai parents and their teens and identifies variables related to communication about sex in urban Thai families. Data were derived from 420 families whose teenage children ages 13-14 years were randomly selected using the probability proportional to size technique. Interviews were conducted with 1 parent and 1 teenage child in each family. In-depth interviews were also conducted in 30 parents and teens drawn from the same 420 families. Results showed that parents were most likely to talk with their teens about body changes and dating; however, less discussion about sex-related issues, birth control, and HIV/AIDS occurred. More daughters than sons reported frequent discussions with their parents about sex. Parents who believed their teens had been involved in sexual activity were more likely to talk about HIV/AIDS and the difficulty of teenagers having babies, instead of talking about sexual intercourse or when to start having sex. Multiple regression analysis indicated that gender of the child (female), parental religiosity, and parental perception of teen sexual activity were significant predictors of increased sexual communication in Thai families. The findings suggest a need for approaches designed to facilitate communication skills about sex-related issues among Thai parents.

  4. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  5. Understanding Teen UX

    DEFF Research Database (Denmark)

    Fitton, Daniel; Iversen, Ole Sejer; Bell, Beth;

    2014-01-01

    UX is a widely explored topic within HCI and has a large practitioners' community. However, the users considered in research and practice, are most often adults -- since adults represent the largest technology market share. However teenagers represent a growing market of unique users, and more...... and methods that we can use to comprehend teen UX now and explore how this may lead to the creation of better interactive products in the future. The workshop will also foster new collaborations, and define new research agendas to grow the research and literature in this area....

  6. Jump starting of continuous improvement through self-assessment

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Boer, Harry; Gertsen, Frank

    2004-01-01

    The innumerable accounts of successful implementation of kaizen in Japan during more than 40 years has led to the expectation that continuous improvement (CI) might offer companies a means to gain and maintain a competitive advantage in the turbulent 1980s and 1990s. However, the majority of CI...

  7. Jump starting of continuous improvement through self-assessment

    DEFF Research Database (Denmark)

    Jørgensen, Frances; Boer, Harry; Gertsen, Frank

    2004-01-01

    The innumerable accounts of successful implementation of kaizen in Japan during more than 40 years has led to the expectation that continuous improvement (CI) might offer companies a means to gain and maintain a competitive advantage in the turbulent 1980s and 1990s. However, the majority of CI i...

  8. Latvian minister wants to jump-start economy

    Index Scriptorium Estoniae

    2008-01-01

    Mõned Läti majandussektorid, eriti ehitussektor kannatavad meetmete pärast, mis valitsus võttis vastu majandusarengu aeglustamiseks. Peaminister Godmanise arvates peaks olema prioriteet majanduskasv, mitte madalamad hinnad

  9. School-to-Work Jump-Start Equity Kit.

    Science.gov (United States)

    Education Development Center, Inc., Newton, MA. Women's Educational Equity Act Dissemination Center.

    This starter kit is a resource for state and local school-to-work (STW) directors, educators, parents, students, business and community, and economic development organizations serving all students through STW. The kit begins with four articles: "STW and Gender Equity: Opportunity for or Barrier to Economic Parity?" (Katherine Hanson, Joyce…

  10. Jump starting your nursing career: toolbox for success.

    Science.gov (United States)

    Jakubik, Louise D

    2008-03-01

    While there is no single path to career advancement in nursing, there are developmental tools and organizational systems to promote nurses' career advancement and to assist in the organization of professional accomplishments. As nurses achieve additional credentialing, certification, licensure and academic credentials, it is important that they list these credentials after their names to market their career accomplishments and expertise. Career tool boxes such as a file system, resume and professional portfolio, are key organizational systems for nurses to keep track of their success and to promote their careers in nursing.

  11. Latvian minister wants to jump-start economy

    Index Scriptorium Estoniae

    2008-01-01

    Mõned Läti majandussektorid, eriti ehitussektor kannatavad meetmete pärast, mis valitsus võttis vastu majandusarengu aeglustamiseks. Peaminister Godmanise arvates peaks olema prioriteet majanduskasv, mitte madalamad hinnad

  12. Can preapproval jump-start the allowance market

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, D.J.; Goffman, J.

    1992-06-01

    With compliance deadlines approaching in three years, utility, environmental and financial planners and their regulators are in the process of grappling with the requirements imposed, and opportunities created, by the acid rain program established under Title 4 of the Clean Air Act amendments of 1990. The novel element of the program - emissions or allowance trading through a nationwide allowance market - presents great challenges for utilities and their regulators. Perhaps the foremost challenge is establishing the allowance market. If state utility commissions subject utilities' compliance strategies to traditional after-the-fact prudence reviews, as tradition would impel them to do, the attendant regulatory risks are likely to push utilities toward more conservative compliance schemes that underuse allowance trading (as the exchange at the head of this article demonstrates). If that happens, the market will fail to develop, and its full potential for environmental benefit at least cost will go unrealized. This, in turn, is likely to strengthen the case for non-market regulatory mechanisms - a vicious circle. In this paper, the authors suggest a way out of this.

  13. Ridge jump process in Iceland

    OpenAIRE

    Garcia, Sebastian

    2010-01-01

    Eastward ridge jumps bring the volcanic zones of Iceland back to the centre of the hotspot in response to the absolute westward drift of the Mid-Atlantic Ridge. Mantellic pulses triggers these ridge jumps. One of them is occurring in Southern Iceland, whereas the exact conditions of the last ridge jump in Northern Iceland remain controversial. The diachronous evolution of these two parts of Iceland may be related to the asymmetric plume-ridge interaction when comparing Northern and Southern I...

  14. and the CMJ jump height

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2016-04-01

    Full Text Available Study aim: The elastic potential energy accumulated in the musculotendinous units during the countermovement phase of a jump adds up to the energy supplied by the contracting muscles used in the take-off phase. Consequently, the total mechanical energy used during the jump may reach higher values. Stiffness represents a quantitative measure of a body’s elastic properties. Therefore, the aim of this study was to establish the relationship between leg stiffness and the countermovement jump height.

  15. Teen Smoking and Birth Outcomes

    OpenAIRE

    MaryBeth Walker; Erdal Tekin; Sally Wallace

    2007-01-01

    In the U.S. teen mothers are more likely to give birth to low birth weight babies than non-teen mothers. There is also substantial evidence that smoking is a risk factor correlated with low birth weight. Low birth weight is a costly outcome in both the short and long term for parents, children, and society at large. This paper examines the causal link between teen age smoking behavior and low birth weight. We use a variety of empirical techniques including fixed effects and a matching estimat...

  16. Teen Eating Disorders: Tips to Protect Your Teen

    Science.gov (United States)

    ... normal body weight, teens can easily develop the perception that they're fat. This can trigger an ... ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://accessmedicine.com. Accessed April 29, 2015. ...

  17. Exploring Lightning Jump Characteristics

    Science.gov (United States)

    Chronis, Themis; Carey, Larry D.; Schultz, Christopher J.; Schultz, Elise; Calhoun, Kristin; Goodman, Steven J.

    2014-01-01

    This study is concerned with the characteristics of storms exhibiting an abrupt temporal increase in the total lightning flash rate (i.e., lightning jump, LJ). An automated storm tracking method is used to identify storm "clusters" and total lightning activity from three different lightning detection systems over Oklahoma, northern Alabama and Washington, D.C. On average and for different employed thresholds, the clusters that encompass at least one LJ (LJ1) last longer, relate to higher Maximum Expected Size of Hail, Vertical Integrated Liquid and lightning flash rates (area-normalized) than the clusters that did not exhibit any LJ (LJ0). The respective mean values for LJ1 (LJ0) clusters are 80 min (35 min), 14 mm (8 mm), 25 kg per square meter (18 kg per square meter) and 0.05 flash per min per square kilometer (0.01 flash per min per square kilometer). Furthermore, the LJ1 clusters are also characterized by slower decaying autocorrelation functions, a result that implies a less "random" behavior in the temporal flash rate evolution. In addition, the temporal occurrence of the last LJ provides an estimate of the time remaining to the storm's dissipation. Depending of the LJ strength (i.e., varying thresholds), these values typically range between 20-60 min, with stronger jumps indicating more time until storm decay. This study's results support the hypothesis that the LJ is a proxy for the storm's kinematic and microphysical state rather than a coincidental value.

  18. More Puddle Jumping

    Science.gov (United States)

    Attari, Babak; Weislogel, Mark; Wollman, Andrew; Chen, Yongkang; Snyder, Trevor

    2016-11-01

    Large droplets and puddles jump spontaneously from sufficiently hydrophobic surfaces during routine drop tower tests. The simple low-cost passive mechanism can in turn be used as an experimental device to investigate dynamic droplet phenomena for drops up to 10,000 times larger than their normal terrestrial counterparts. We provide or confirm quick and qualitative design guides for such 'drop shooters' as employed in drop tower tests including relationships to predict droplet ejection durations and velocities as functions of drop volume, surface texture, surface contour, wettability pattern, drop volume, and fluid properties including contact angle. The latter are determined via profile image comparisons with numerical equilibrium interface computations. Water drop volumes of 0.04 to 400 mL at ejection speeds of -0.007 to 0.12 m/s are demonstrated. An example application of the puddle jump method is made to the classic problem of regime mapping for low-gravity phase change heat transfer for large impinging drops. Many other candidate problems might be identified.

  19. Stem Cell Transplants (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Stem Cell Transplants KidsHealth > For Teens > Stem Cell Transplants Print ... Does it Take to Recover? Coping What Are Stem Cells? As you probably remember from biology class, every ...

  20. Teen Brain: Still Under Construction

    Science.gov (United States)

    ... Brain Reprints For more information Share The Teen Brain: Still Under Construction Download PDF Download ePub Order ... the ups and downs of adolescence. The "Visible" Brain A clue to the degree of change taking ...

  1. Toxic Shock Syndrome (For Teens)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Toxic Shock Syndrome KidsHealth > For Teens > Toxic Shock Syndrome Print ... it, then take some precautions. What Is Toxic Shock Syndrome? If you're a girl who's had ...

  2. Dealing with Addiction (For Teens)

    Science.gov (United States)

    ... Help Someone Who's Being Bullied? Volunteering Dealing With Addiction KidsHealth > For Teens > Dealing With Addiction Print A ... is even harder. What Are Substance Abuse and Addiction? The difference between substance abuse and addiction is ...

  3. Pelvic Inflammatory Disease (For Teens)

    Science.gov (United States)

    ... lead to internal scarring that might cause ongoing pelvic pain, infertility, or an ectopic pregnancy. What Are the ... the inability to have a baby) and chronic pelvic pain. A teen girl or woman who has had ...

  4. Common Sleep Problems (For Teens)

    Science.gov (United States)

    ... sleep when a person has the most vivid dreams. Why Do Teens Have Trouble Sleeping? Research shows ... will look at your overall health and sleep habits. In addition to doing a physical examination, the ...

  5. About Teen Suicide (For Parents)

    Science.gov (United States)

    ... bullying are at greater risk of suicidal thoughts. Factors that increase the risk of suicide among teens include: a psychological disorder, especially depression , bipolar disorder , and alcohol and drug use (in ...

  6. Preventing Teen Pregnancy PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2015-04-07

    This 60 second public service announcement is based on the April 2015 CDC Vital Signs report. Teen births in the U.S. have declined, but still, more than 273,000 infants were born to teens ages 15 to 19 in 2013. Learn about the most effective types of birth control.  Created: 4/7/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/7/2015.

  7. Sex Differences in Countermovement Jump Phase Characteristics

    Directory of Open Access Journals (Sweden)

    John J. McMahon

    2017-01-01

    Full Text Available The countermovement jump (CMJ is commonly used to explore sex differences in neuromuscular function, but previous studies have only reported gross CMJ measures or have partly examined CMJ phase characteristics. The purpose of this study was to explore differences in CMJ phase characteristics between male and female athletes by comparing the force-, power-, velocity-, and displacement-time curves throughout the entire CMJ, in addition to gross measures. Fourteen men and fourteen women performed three CMJs on a force platform from which a range of kinetic and kinematic variables were calculated via forward dynamics. Jump height (JH, reactive strength index modified, relative peak concentric power, and eccentric and concentric displacement, velocity, and relative impulse were all greater for men (g = 0.58–1.79. Relative force-time curves were similar between sexes, but relative power-, velocity-, and displacement-time curves were greater for men at 90%–95% (immediately before and after peak power, 47%–54% (start of eccentric phase and 85%–100% (latter half of concentric phase, and 65%–87% (bottom of countermovement and initial concentric phase of normalized jump time, respectively. The CMJ distinguished between sexes, with men demonstrating greater JH through applying a larger concentric impulse and, thus, achieving greater velocity throughout most of the concentric phase, including take-off.

  8. Hydraulic jumps in a channel

    DEFF Research Database (Denmark)

    Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected...

  9. An evidence-based parenting intervention with inner-city teen mothers.

    Science.gov (United States)

    Williams, Tiffany H; Dumas, Bonnie P; Edlund, Barbara J

    2013-07-01

    The consequences of teen pregnancy have a substantial negative impact on both the teen mother and her child. Recent evidence clearly supports parenting education as the most effective means for improving adolescent parenting skills. This study evaluated the effectiveness of a school-based program using an evidence-based educational intervention to improve parenting style in high school teen mothers. Teen mothers, from 15 to 18 years of age, in a Title 1 high school were recruited from the Early Head Start program. Two groups of teens (N = 10) completed a pre-parenting style survey, enrolled in an 8- or 12-week group educational session, and completed a post-parenting style survey. While quantitative data did not yield a change in parenting style, qualitative findings highlighted a strong need for teens to "tell their story" and to share personal experiences related to parenting. These findings lend support for the role of parenting educational interventions in high schools with teens at high risk for pregnancy.

  10. Jump conditions in transonic equilibria

    Energy Technology Data Exchange (ETDEWEB)

    Guazzotto, L.; Betti, R. [Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627 (United States); Jardin, S. C. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)

    2013-04-15

    In the present paper, the numerical calculation of transonic equilibria, first introduced with the FLOW code in Guazzotto et al.[Phys. Plasmas 11, 604 (2004)], is critically reviewed. In particular, the necessity and effect of imposing explicit jump conditions at the transonic discontinuity are investigated. It is found that 'standard' (low-{beta}, large aspect ratio) transonic equilibria satisfy the correct jump condition with very good approximation even if the jump condition is not explicitly imposed. On the other hand, it is also found that high-{beta}, low aspect ratio equilibria require the correct jump condition to be explicitly imposed. Various numerical approaches are described to modify FLOW to include the jump condition. It is proved that the new methods converge to the correct solution even in extreme cases of very large {beta}, while they agree with the results obtained with the old implementation of FLOW in lower-{beta} equilibria.

  11. With One Voice: America's Adults and Teens Sound Off about Teen Pregnancy. A National Survey.

    Science.gov (United States)

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    These charts describe adults' and adolescents' views on teen sex and pregnancy. Data come from national surveys of adults and adolescents that examined attitudes toward teen sex and pregnancy, factors influencing teens' sexual decisions, parents' roles, and adults' and teens' advice for policymakers. There is near unanimous agreement among both…

  12. Differential social evaluation of pregnant teens, teen mothers and teen fathers by university students

    OpenAIRE

    Weed, Keri; Nicholson, Jody S.

    2014-01-01

    Youth may be particularly attuned to social evaluation during the teen years with implications for physical and mental health. Negative attitudes and stereotypes constitute an important type of social evaluative threat. Pregnant and parenting teens not only encounter challenges associated with their early transition to parenthood, but also are confronted with unfavourable attitudes of others. A university sample of 255 men and women responded to surveys targeting their feelings and beliefs ab...

  13. Parent and teen agreement on driving expectations prior to teen licensure.

    Science.gov (United States)

    Hamann, Cara J; Ramirez, Marizen; Yang, Jingzhen; Chande, Vidya; Peek-Asa, Corinne

    2014-01-01

    To examine pre-licensure agreement on driving expectations and predictors of teen driving expectations among parent-teen dyads. Cross-sectional survey of 163 parent-teen dyads. Descriptive statistics, weighted Kappa coefficients, and linear regression were used to examine expectations about post-licensure teen driving. Teens reported high pre-licensure unsupervised driving (N = 79, 48.5%) and regular access to a car (N = 130, 81.8%). Parents and teens had low agreement on teen driving expectations (eg, after dark, κw = 0.23). Each time teens currently drove to/from school, their expectation of driving in risky conditions post-licensure increased (β = 0.21, p = .02). Pre-licensure improvement of parent-teen agreement on driving expectations are needed to have the greatest impact on preventing teens from driving in high risk conditions.

  14. PCOS: What Teens Need to Know

    Science.gov (United States)

    ... What Teens Need to Know Fact Sheet PCOS: What Teens Need to Know September 2013 Download PDFs ... Dorothy Shulman, MD A. Musa Zamah, MD, PhD What is PCOS? PCOS, which stands for polycystic ovary ...

  15. Parenting Skills: Tips for Raising Teens

    Science.gov (United States)

    ... adult is no small task. Understand the parenting skills you need to help guide your teen. By ... teen and encourage responsible behavior. Use these parenting skills to deal with the challenges of raising a ...

  16. Sexual Attraction and Orientation (For Teens)

    Science.gov (United States)

    ... person is gay or straight. continue What Is LGBT? You may see the letters "LGBT" or ("LGBTQ") ... LGBT teens. previous continue What's It Like for LGBT Teens? For many LGBT people, it can feel ...

  17. The Teen Brain: 6 Things to Know

    Science.gov (United States)

    ... and adults For More Information Reprints Share The Teen Brain: 6 Things to Know Download PDF Download ePub ... Here are 6 things to know about the teen brain: Your brain does not keep getting bigger as ...

  18. Supporting Teens in Chicago's Humboldt Park.

    Science.gov (United States)

    Abbate, Nancy M.

    1990-01-01

    Describes a Youth Service Project Program for teen mothers in Chicago. The program uses a bicultural approach that provides teens with a supportive social network and the opportunity to acquire parenting and literacy skills. (PCB)

  19. Especially for Teens: You and Your Sexuality

    Science.gov (United States)

    ... QUESTIONS FAQ042 ESPECIALLY FOR TEENS You and Your Sexuality (Especially for Teens) • What happens during puberty? • What ... feelings expressed? There are many ways to express sexuality. Sexual intercourse is one way. Others include masturbation , ...

  20. Consequences of teen-age parenting.

    Science.gov (United States)

    Nord, C W; Moore, K A; Morrison, D R; Brown, B; Myers, D E

    1992-09-01

    The changing context of teen-age childbearing and current related controversies are reviewed. Recent research about the consequences of teen-age childbearing for the teen-age mother, the father, and for the children born is examined. The article also summarizes current knowledge about the consequences of teen-age childbearing with regard to the mother's educational attainment, marital experience, subsequent fertility behavior, labor force experience and occupational attainment, and experience with poverty and welfare.

  1. Preventing Pregnancy in Younger Teens PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2014-04-08

    This 60 second public service announcement is based on the April 2014 CDC Vital Signs report. Births to teens are declining, still, more than 305,000 teens ages 15 to 19 gave birth. This program discusses what health care providers, parents, and teens can do to help prevent teen pregnancy.  Created: 4/8/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/8/2014.

  2. The Right Start for America's Newborns: A Decade of City and State Trends (1990-1999). Child Trends/KIDS COUNT Working Paper.

    Science.gov (United States)

    Wertheimer, Richard; O'Hare, William; Croan, Tara; Jager, Justin; Long, Melissa; Reynolds, Megan

    This paper traces the history of "The Right Start," discussing differences between the 50 largest cities and the nation overall and differences among states. It highlights eight measures reflecting a healthy start: teen births, repeat teen births, births to unmarried women, births to mothers with low educational attainment, late or no pregnancy…

  3. Three Years of Teen Court Offender Outcomes

    Science.gov (United States)

    Forgays, Deborah Kirby

    2008-01-01

    Since 1983, Teen Courts have offered a judicial alternative for many adolescent offenders. In the first year of the Whatcom County Teen Court Program, a small sample of Teen Court offenders had more favorable outcomes than did Court Diversion offenders. In the current study, the results are based on a three-year sample of 84 Whatcom County…

  4. Teens, Technology, and School. Data Memo

    Science.gov (United States)

    Hitlin, Paul; Rainie, Lee

    2005-01-01

    Teen use of the internet at school has grown 45% since 2000. The vast majority of teens and their parents believe that the use of the internet helps students in the classroom and in their studies, but some teens believe too many of their peers use the internet to cheat. The internet is an important element in the overall educational experience of…

  5. African American teen mothers' perceptions of parenting.

    Science.gov (United States)

    Wayland, J; Rawlins, R

    1997-02-01

    The purpose of this study was to describe the childbearing African American teens' perceptions of parenting based on their own experiences. Focus group discussions were held with 17 teens in their school setting for 50 minutes each week. Group discussions were audiotaped, tapes were transcribed, and then analyzed for common themes. The unmarried teens ranged in age from 15 to 18 years. Findings indicated that the teens depended on grandmothers to provide child care and for information about parenting. The teens identified parenting problems including crying, discipline, and conflicts dealing with grandmothers and the child's father. Teens wanted more information about breastfeeding and minor childhood diseases. The researchers identified that teens lacked information about their children's growth and development and safety issues. Findings have implications for nurses who care for childbearing teens and their children; and those involved in planning and implementing parent education programs for African American teen mothers and their families. Further research is indicated with larger samples of African American teens; and to explore the context of family relationships in which teen mothers and grandmothers share parenting for the teens' children.

  6. Learning Guide for New Mexico Teens Talk.

    Science.gov (United States)

    Mokler, Mary M.

    Teens Talk is a project conducted to develop peer leadership among pregnant/parenting teens (both male and female) by participation in panels. After training, the panels present information as well as experiences and attitudes to adult community groups to raise awareness and support, to youth groups to prevent teen pregnancy, and to other…

  7. Frequency Jump Detection and Analysis

    Science.gov (United States)

    2008-12-01

    CUMULATIVE SUM JUMP DETECTION The Cumulative Sum ( CUSUM ) is a classic change-point analysis technique that uses the cumulative sum of the...sum and y is the average of the data. The CUSUM slope indicates the value of the data with respect to the overall average. A flat cumulative sum...sudden change in the CUSUM slope indicates a jump in the data. The CUSUM plot for a data set having a single jump will have a V or inverted V shape

  8. Teen theaters grapple with issues.

    Science.gov (United States)

    Pugni, J L

    1984-01-01

    At this time there are about 20 Planned Parenthood teen theater groups throughout the US. The idea originated in New York in 1973, when the staff of the Family Planning Division of the New York Medical College needed an effective way to reach adolescents about important issues. FOCUS, a teen family life theater sponsored by Planned Parenthood of Greater Charlotte, performs skits about life as seen from the teenager's perspective. The teenagers do not use a script but create their performances from their own experiences, expressed through carefully learned improvisational techniques. This approach gives the presentations an authentic flavor that enables the troupe to connect with the audience. The topics dealt with vary. For example, 1982-83 shows included peer pressure, divorce, teenage pregnancy, drinking, teenage suicide, parent-teen relationships, and loneliness. The performances do not offer absolute answers but rather pose important questions to the audience. Following the performance the actors and actresses return to the stage, still portraying their characters, and invite the audience to ask questions and discuss possible alternatives for the characters. THE SOURCE is the Teen Council of Planned Parenthood of Southwest Florida. It works to inform the community of problems teenagers face by presenting short plays, written, directed, and cast by teens themselves. Through education, honest answers, healthy building of self esteem, and parent support, SOURCE members reach a higher level of self awareness. They then share what they learn with their families, peers, and the community through performance and special events. THE SOURCE, formed in October 1980, grew out of Planned Parenthood's belief that if teens feel self worth, their decision-making process will be affected less by peer pressure and negative social influences. The Youth Expression Theater (YET) of Cambridge is an education outreach project of the Planned Parenthood League of Massachusetts (PPLM

  9. teen court教育学的研究

    OpenAIRE

    太田, 和敬

    2012-01-01

    Teen Courts are peer-run courts that are authorized to pass sentence on first-time juvenile offenders for certain non-violent misdemeanors. Few juveniles commit a second offense. The teen court system is believed to have some elements that encourage teens to go straight: 1. Teen court focuses on first misdemeanors since failure to intervene may lead to teens becoming felons. 2. Teens can choose the justice system they want tobe subjected to. Choice is crucial to teens accepting responsibility...

  10. Realized Jump Risk and Equity Return in China

    OpenAIRE

    Guojin Chen; Xiaoqun Liu; Peilin Hsieh; Xiangqin Zhao

    2014-01-01

    We utilize the realized jump components to explore a new jump (including nonsystematic jump and systematic jump) risk factor model. After estimating daily realized jumps from high-frequency transaction data of the Chinese A-share stocks, we calculate monthly jump size, monthly jump standard deviation, and monthly jump arrival rate and then use those monthly jump factors to explain the return of the following month. Our empirical results show that the jump tail risk can explain the equity retu...

  11. Rook Jumping Maze Design Considerations

    Science.gov (United States)

    Neller, Todd W.; Fisher, Adrian; Choga, Munyaradzi T.; Lalvani, Samir M.; McCarty, Kyle D.

    We define the Rook Jumping Maze, provide historical perspective, and describe a generation method for such mazes. When applying stochastic local search algorithms to maze design, most creative effort concerns the definition of an objective function that rates maze quality. We define and discuss several maze features to consider in such a function definition. Finally, we share our preferred design choices, make design process observations, and note the applicability of these techniques to variations of the Rook Jumping Maze.

  12. The Effect of Depth Jumps and Weight Training on Leg Strength and Vertical Jump.

    Science.gov (United States)

    Clutch, David; And Others

    1983-01-01

    Two experiments examined the results of depth jumping programs to determine: (1) whether certain depth jumping routines, when combined with weight training, are better than others; and (2) the effect of depth jumping on athletes already in training. Results indicated that depth jumping is effective, but no more so than regular jumping routines.…

  13. Special Considerations in Distracted Driving with Teens

    Science.gov (United States)

    Durbin, Dennis R; McGehee, Daniel V; Fisher, Donald; McCartt, Anne

    2014-01-01

    Novice teen drivers have long been known to have an increased risk of crashing, as well as increased tendencies toward unsafe and risky driving behaviors. Teens are unique as drivers for several reasons, many of which have implications specifically in the area of distracted driving. This paper reviews several of these features, including the widespread prevalence of mobile device use by teens, their lack of driving experience, the influence of peer passengers as a source of distraction, the role of parents in influencing teens’ attitudes and behaviors relevant to distracted driving and the impact of laws designed to prevent mobile device use by teen drivers. Recommendations for future research include understanding how engagement in a variety of secondary tasks by teen drivers affects their driving performance or crash risk; understanding the respective roles of parents, peers and technology in influencing teen driver behavior; and evaluating the impact of public policy on mitigating teen crash risk related to driver distraction. PMID:24776228

  14. Polybutadiene (Jumping Rubber)

    Science.gov (United States)

    Fine, Leonard W.

    1996-01-01

    This laboratory procedure starts with a violet suspension of an 'alfin' catalyst being added to a bottle containing a solution of 1,3-butadiene in pentane. The bottle is corked and shaken for several seconds. The mixture sets to a gel, and within 2 minutes the contents erupt from the bottle.

  15. Freeze Frame 2012: A Snapshot of America's Teens

    Science.gov (United States)

    Stewart, Alison; Kaye, Kelleen

    2012-01-01

    When it comes to making decisions about sex, teens today are doing far better than they were 20 years ago. Fewer teens are having sex, and among those who are, more teens are using contraception. The happy result is that teen pregnancy and birth rates have declined dramatically. Despite this extraordinary progress, teen pregnancy and childbearing…

  16. Test-retest reliability of jump execution variables using mechanography: A comparison of jump protocols

    Science.gov (United States)

    Mechanography during the vertical jump test allows for evaluation of force-time variables reflecting jump execution, which may enhance screening for functional deficits that reduce physical performance and determining mechanistic causes underlying performance changes. However, utility of jump mechan...

  17. Getting Started with Hibernate 3

    CERN Document Server

    Elliott, James

    2008-01-01

    Hibernate has clearly arrived. Are you ready to benefit from its simple way of working with relational databases as Java objects? This PDF updates the introductory material from the award-winning Hibernate: A Developer's Notebook to teach you how to jump right in and get productive with the current release of Hibernate. You'll be walked through the ins and outs of setting up Hibernate and some related tools that make it easier to use--and that may give you new ideas about how to store information in your Java programs. In short, this PDF gives you exactly the information you need to start u

  18. Smoking and Asthma (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Smoking and Asthma KidsHealth > For Teens > Smoking and Asthma A A A What's in this ... family photo albums full of pictures with people smoking at all kinds of events, from kids' birthday ...

  19. About Teen Suicide (For Parents)

    Science.gov (United States)

    ... to remember how it felt to be a teen, caught in that gray area between childhood and adulthood. Sure, it's a time of tremendous possibility, but it also can be a period of stress and worry. There's pressure to fit in socially, to perform academically, and to act responsibly. Adolescence is also ...

  20. All about Menstruation (For Teens)

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness All About Menstruation KidsHealth > For Teens > All About Menstruation Print A A A What's in ... call it menarche . Menarche doesn't happen until all the parts of a girl's reproductive system have ...

  1. E-Cigarettes (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness E-Cigarettes KidsHealth > For Teens > E-Cigarettes A A ... Habit en español Los cigarrillos electrónicos What Are E-Cigarettes? E-cigarettes look high tech, so it's ...

  2. High School Teen Mentoring Handbook

    Science.gov (United States)

    Alberta Advanced Education and Technology, 2009

    2009-01-01

    Big Brothers Big Sisters Edmonton & Area, in partnership with Alberta Advanced Education and Technology, are providing the High School Teen Mentoring Program, a school-based mentoring program where mentor-mentee matches meet for one hour per week to engage in relationship-building activities at an elementary school. This initiative aims to…

  3. Urinary Tract Infections (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Urinary Tract Infections KidsHealth > For Teens > Urinary Tract Infections Print A ... especially girls — visit a doctor. What Is a Urinary Tract Infection? A bacterial urinary tract infection (UTI) is the ...

  4. Sickle Cell Crisis (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Sickle Cell Crisis (Pain Crisis) KidsHealth > For Teens > Sickle Cell ... Crisis drepanocíticas (Crisis de dolor) What Is a Sickle Cell Crisis? Sickle cell disease changes the shape of ...

  5. Inflammatory Bowel Disease (For Teens)

    Science.gov (United States)

    ... IBD? IBD is most likely to happen in people in their late teens and twenties. However, kids as young as 5 years old have been known to ... IBD, managing your symptoms, and keeping a positive attitude can help get you back on track. Reviewed by: J. Fernando del Rosario, MD Date reviewed: August ... Kids For Parents MORE ON THIS TOPIC Dealing With a Health ...

  6. Common Sleep Problems (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Common Sleep Problems KidsHealth > For Teens > Common Sleep Problems Print A A A What's in ... insomnia — trouble falling or staying asleep. The most common cause of insomnia is stress . But all sorts ...

  7. Starting electronics

    CERN Document Server

    Brindley, Keith

    2005-01-01

    Starting Electronics is unrivalled as a highly practical introduction for hobbyists, students and technicians. Keith Brindley introduces readers to the functions of the main component types, their uses, and the basic principles of building and designing electronic circuits. Breadboard layouts make this very much a ready-to-run book for the experimenter; and the use of multimeter, but not oscilloscopes, puts this practical exploration of electronics within reach of every home enthusiast's pocket. The third edition has kept the simplicity and clarity of the original. New material

  8. Gravity current jump conditions, revisited

    Science.gov (United States)

    Ungarish, Marius; Hogg, Andrew J.

    2016-11-01

    Consider the flow of a high-Reynolds-number gravity current of density ρc in an ambient fluid of density ρa in a horizontal channel z ∈ [ 0 , H ] , with gravity in - z direction. The motion is often modeled by a two-layer formulation which displays jumps (shocks) in the height of the interface, in particular at the leading front of the dense layer. Various theoretical models have been advanced to predict the dimensionless speed of the jump, Fr = U /√{g' h } ; g' , h are reduced gravity and jump height. We revisit this problem and using the Navier-Stokes equations, integrated over a control volume embedding the jump, derive balances of mass and momentum fluxes. We focus on understanding the closures needed to complete this model and we show the vital need to understand the pressure head losses over the jump, which we show can be related to the vorticity fluxes at the boundaries of the control volume. Our formulation leads to two governing equations for three dimensionless quantities. Closure requires one further assumption, depending on which we demonstrate that previous models for gravity current fronts and internal bores can be recovered. This analysis yield new insights into existing results, and also provides constraints for potential new formulae.

  9. Coalescence-induced nanodroplet jumping

    Science.gov (United States)

    Cha, Hyeongyun; Xu, Chenyu; Sotelo, Jesus; Chun, Jae Min; Yokoyama, Yukihiro; Enright, Ryan; Miljkovic, Nenad

    2016-10-01

    Water vapor condensation on superhydrophobic surfaces has received much attention in recent years due to the ability of such surfaces to shed microscale water droplets via coalescence-induced droplet jumping, resulting in heat transfer, anti-icing, and self-cleaning performance enhancement. Here we report the coalescence-induced removal of water nanodroplets (R ≈500 nm ) from superhydrophobic carbon nanotube (CNT) surfaces. The two-droplet coalescence time is measured for varying droplet Ohnesorge numbers, confirming that coalescence prior to jumping is governed by capillary-inertial dynamics. By varying the conformal hydrophobic coating thickness on the CNT surface, the minimum jumping droplet radius is shown to increase with increasing solid fraction and decreasing apparent advancing contact angle, allowing us to explore both hydrodynamic limitations stemming from viscous dissipation and surface adhesion limitations. We find that, even for the smallest nanostructure length scale (≤100 nm) and lowest surface adhesions, nonideal surface interactions and the evolved droplet morphology play defining roles in limiting the minimum size for jumping on real surfaces. The outcomes of this work demonstrate the ability to passively shed nanometric water droplets, which has the potential to further increase the efficiency of systems that can harness jumping droplets for a wide range of energy and water applications.

  10. For Parents of Children and Teens Living with Lupus

    Science.gov (United States)

    ... Team Make Your Mark Message Boards | Store children/teens Home > Tag: children/teens At one time lupus was thought to be ... you monitor bone health in a child or teen taking corticosteroids? Is the HPV vaccine safe for ...

  11. Understanding the physics of bungee jumping

    Science.gov (United States)

    Heck, André; Uylings, Peter; Kędzierska, Ewa

    2010-01-01

    Changing mass phenomena like the motion of a falling chain, the behaviour of a falling elastic bar or spring, and the motion of a bungee jumper surprise many a physicist. In this article we discuss the first phase of bungee jumping, when the bungee jumper falls, but the bungee rope is still slack. In instructional material this phase is often considered a free fall, but when the mass of the bungee rope is taken into account, the bungee jumper reaches acceleration greater than g. This result is contrary to the usual experience with free falling objects and therefore hard to believe for many a person, even an experienced physicist. It is often a starting point for heated discussions about the quality of the experiments and the physics knowledge of the experimentalist, or it may even prompt complaints about the quality of current physics education. But experiments do reveal the truth and students can do them supported by information and communication technology (ICT) tools. We report on a research project done by secondary school students and use their work to discuss how measurements with sensors, video analysis of self-recorded high-speed video clips and computer modelling allow study of the physics of bungee jumping.

  12. Correlates and consequences of parent-teen incongruence in reports of teens' sexual experience.

    Science.gov (United States)

    Mollborn, Stefanie; Everett, Bethany

    2010-07-01

    Using the National Longitudinal Study of Adolescent Health, factors associated with incongruence between parents' and adolescents' reports of teens' sexual experience were investigated, and the consequences of inaccurate parental knowledge for adolescents' subsequent sexual behaviors were explored. Most parents of virgins accurately reported teens' lack of experience, but most parents of teens who had had sex provided inaccurate reports. Binary logistic regression analyses showed that many adolescent-, parent-, and family-level factors predicted the accuracy of parents' reports. Parents' accurate knowledge of their teens' sexual experience was not found to be consistently beneficial for teens' subsequent sexual outcomes. Rather, parents' expectations about teens' sexual experience created a self-fulfilling prophecy, with teens' subsequent sexual outcomes conforming to parents' expectations. These findings suggest that research on parent-teen communication about sex needs to consider the expectations being expressed, as well as the information being exchanged.

  13. How far can Tarzan jump?

    Science.gov (United States)

    Shima, Hiroyuki

    2012-11-01

    The tree-based rope swing is a popular recreational facility, often installed in outdoor areas. Hanging from a rope, users drop from a high platform and then swing at great speed like ‘Tarzan’, finally jumping ahead to land on the ground. The question naturally arises, how far can Tarzan jump using the swing? In this paper, I present an introductory analysis of the mechanics of the Tarzan swing, a large pendulum-like swing with Tarzan himself attached as weight. This enables determination of how much further forward Tarzan can jump using a given swing apparatus. The discussion is based on elementary mechanics and is, therefore, expected to provide rich opportunities for investigations using analytic and numerical methods.

  14. How far can Tarzan jump?

    CERN Document Server

    Shima, Hiroyuki

    2012-01-01

    The tree-based rope swing is a popular recreation facility, often installed in outdoor areas, giving pleasure to thrill-seekers. In the setting, one drops down from a high platform, hanging from a rope, then swings at a great speed like "Tarzan", and finally jumps ahead to land on the ground. The question now arises: How far can Tarzan jump by the swing? In this article, I present an introductory analysis of the Tarzan swing mechanics, a big pendulum-like swing with Tarzan himself attached as weight. The analysis enables determination of how farther forward Tarzan can jump using a given swing apparatus. The discussion is based on elementary mechanics and, therefore, expected to provide rich opportunities for investigations using analytic and numerical methods.

  15. Special Considerations in Distracted Driving with Teens

    OpenAIRE

    Durbin, Dennis R.; McGehee, Daniel V.; Fisher, Donald; McCartt, Anne

    2014-01-01

    Novice teen drivers have long been known to have an increased risk of crashing, as well as increased tendencies toward unsafe and risky driving behaviors. Teens are unique as drivers for several reasons, many of which have implications specifically in the area of distracted driving. This paper reviews several of these features, including the widespread prevalence of mobile device use by teens, their lack of driving experience, the influence of peer passengers as a source of distraction, the r...

  16. Effects of a Low-Load Gluteal Warm-Up on Explosive Jump Performance

    Directory of Open Access Journals (Sweden)

    Comyns Thomas

    2015-06-01

    Full Text Available The purpose of this study was to investigate the effects of a low-load gluteal warm-up protocol on countermovement and squat jump performance. Research by Crow et al. (2012 found that a low-load gluteal warm-up could be effective in enhancing peak power output during a countermovement jump. Eleven subjects performed countermovement and squat jumps before and after the gluteal warm-up protocol. Both jumps were examined in separate testing sessions and performed 30 seconds, and 2, 4, 6 & 8 minutes post warm-up. Height jumped and peak ground reaction force were the dependent variables examined in both jumps, with 6 additional variables related to fast force production being examined in the squat jump only. All jumps were performed on a force platform (AMTI OR6-5. Repeated measures analysis of variance found a number of significant differences (p ≤ 0.05 between baseline and post warm-up scores. Height jumped decreased significantly in both jumps at all rest intervals excluding 8 minutes. Improvement was seen in 7 of the 8 recorded SJ variables at the 8 minute interval. Five of these improvements were deemed statistically significant, namely time to peak GRF (43.0%, and time to the maximum rate of force development (65.7% significantly decreased, while starting strength (63.4%, change of force in first 100 ms of contraction (49.1% and speed strength (43.6% significantly increased. The results indicate that a gluteal warm-up can enhance force production in squat jumps performed after 8 minutes recovery. Future research in this area should include additional warm-up intervention groups for comparative reasons.

  17. Reduced Disparities in Birth Rates Among Teens

    Science.gov (United States)

    ... from the Field Projects and Initiatives Health Centers Male Involvement Communitywide Initiatives Communitywide Teen Pregnancy Prevention Initiative Partners Contraceptive Action Plan Program Tools and Resources Community Mobilization ...

  18. The beginning of time observed in quantum jumps

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, Arno [CCQS, Physics Department, University of Texas, Austin, TX (United States); Bryant, Peter W. [IBM Research, Rio de Janeiro (Brazil); Uncu, Haydar [Department of Physics, Adnan Menderes University, Aydin (Turkey); Wickramasekara, Sujeev [Department of Physics, Grinnell College, Grinnell, IA (United States); Schleich, Wolfgang P. [Institut fuer Quantenphysik and Center for Integrated Quantum Science and Technology, Universitaet Ulm (Germany); Hagler Institute for Advanced Study, Texas A and M University, College Station, TX (United States); Texas A and M AgriLife, Institute for Quantum Science and Engineering (IQSE) and Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States)

    2017-06-15

    The phenomenon of quantum jumps observed in a single ion stored in a trap brings to light intimate connections between three different concepts of quantum physics: (i) quantum state trajectories, (ii) Gamow states, and (iii) the arrow of time. In particular, it allows us to identify the starting time of the semigroup time evolution. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Alzheimer's Deaths Jump 55 Percent: CDC

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_165941.html Alzheimer's Deaths Jump 55 Percent: CDC More patients also ... News) -- As more baby boomers age, deaths from Alzheimer's disease have jumped 55 percent, and in a ...

  20. Inherent enumerability of strong jump-traceability

    CERN Document Server

    Diamondstone, David; Turetsky, Daniel

    2011-01-01

    We show that every strongly jump-traceable set obeys every benign cost function. Moreover, we show that every strongly jump-traceable set is computable from a computably enumerable strongly jump-traceable set. This allows us to generalise properties of c.e.\\ strongly jump-traceable sets to all such sets. For example, the strongly jump-traceable sets induce an ideal in the Turing degrees; the strongly jump-traceable sets are precisely those that are computable from all superlow Martin-L\\"{o}f random sets; the strongly jump-traceable sets are precisely those that are a base for $\\text{Demuth}_{\\text{BLR}}$-randomness; and strong jump-traceability is equivalent to strong superlowness.

  1. pH-jump induced α-helix folding of poly-L-glutamic acid

    Energy Technology Data Exchange (ETDEWEB)

    Donten, Mateusz L. [Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); Hamm, Peter, E-mail: phamm@pci.uzh.ch [Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland)

    2013-08-30

    Highlights: ► pH-jump as truly biomimetic tool to initiate non-equilibrium dynamics of biomolecules. ► Design criteria to widen the applicability of pH-jumps are developed. ► Folding of poly-L-Glu in dependence of starting pH, pH jump size and helix length. ► Length dependence provides strong evidence for a nucleation–propagation scenario. - Abstract: pH jumps are a truly biomimetic technique to initiate non-equilibrium dynamics of biomolecules. In this work, the pH jump induced α-helix folding of poly-L-glutamic acid is investigated upon proton release from o-nitrobenzaldehyde. The aim of this work is twofold: On the one hand, design criteria of pH jump experiments are discussed, on the other hand, the folding mechanism of poly-L-glutamic acid is clarified by probing the IR response of the amide I band. Its folding kinetics is studied in dependence of the starting pD, the size of the pD jump and the length of the helix. While no dependence on the first two parameters could be detected, the folding time varies from 0.6 μs to 1.8 μs for helix lengths of 20 residue to 440 residue, respectively. It converges to a long-length limit at about 50 residue, a result which is attributed to a nucleation–propagation mechanism.

  2. Model for polygonal hydraulic jumps

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Watanabe, Shinya; Bohr, Tomas

    2012-01-01

    ) near the free surface in the jump region. The model consists of mass conservation and radial force balance between hydrostatic pressure and viscous stresses on the roller surface. In addition, we consider the azimuthal force balance, primarily between pressure and viscosity, but also including...

  3. Jumping property of Lyapunov values

    Institute of Scientific and Technical Information of China (English)

    毛锐; 王铎

    1996-01-01

    A sufficient condition for fcth Lyapunov value to be zero for planar polynomial vector fields is given, which extends the result of "jumping property’ of Lyapunov values obtained by Wang Duo to more general cases. A concrete example that the origin cannot be weak focus of order 1, 2, 4, 5, 8 is presented.

  4. Teen Sized Humanoid Robot: Archie

    Science.gov (United States)

    Baltes, Jacky; Byagowi, Ahmad; Anderson, John; Kopacek, Peter

    This paper describes our first teen sized humanoid robot Archie. This robot has been developed in conjunction with Prof. Kopacek’s lab from the Technical University of Vienna. Archie uses brushless motors and harmonic gears with a novel approach to position encoding. Based on our previous experience with small humanoid robots, we developed software to create, store, and play back motions as well as control methods which automatically balance the robot using feedback from an internal measurement unit (IMU).

  5. A jump forwards with mathematics and physics

    NARCIS (Netherlands)

    A. Heck; P. Uylings

    2011-01-01

    We jump on human body motions such as bouncing on a jumping stick, hopping, and making kangaroo jumps. Students can record the movements with a digital camera and use their video clips to investigate the motions with suitable video analysis and modelling software. We discuss some mathematical models

  6. Strawberry Shortcake and Other Jumping Rope Ideas.

    Science.gov (United States)

    Adams, Polly K.; Taylor, Michaell K.

    Information, guidelines, and activities for jumping rope are given. A short history of jumping rope explains how it evolved from a spring ritual for men to a play activity involving mostly young girls. Physical and cultural reasons are given as to why jumping rope has been more a sport for girls than for boys. Research studies are noted which show…

  7. Strawberry Shortcake and Other Jumping Rope Ideas.

    Science.gov (United States)

    Adams, Polly K.; Taylor, Michaell K.

    Information, guidelines, and activities for jumping rope are given. A short history of jumping rope explains how it evolved from a spring ritual for men to a play activity involving mostly young girls. Physical and cultural reasons are given as to why jumping rope has been more a sport for girls than for boys. Research studies are noted which show…

  8. Mesopause jumps at Antarctic latitudes

    Science.gov (United States)

    Lübken, Franz-Josef; Höffner, Josef; Becker, Erich; Latteck, Ralph; Murphy, Damian

    2016-04-01

    Recent high resolution temperature measurements by resonance lidar at Davis (69°S) occasionally showed a sudden mesopause altitude increase by ˜5 km and an associated mesopause temperature decrease by ˜10 K. We present further observations which are closely related to this 'mesopause jump', namely the increase of mean height of polar mesospheric summer echoes (PMSE) observed by a VHF radar, very strong westward winds in the upper mesosphere measured by an MF radar, and relatively large eastward winds in the stratosphere taken from reanalysis. We compare to similar observations in the Northern Hemisphere, namely at ALOMAR (69°N) where such mesopause jumps have never been observed. We present a detailed explanation of mesopause jumps. They occur only when stratospheric winds are moderately eastward and mesospheric winds are very large (westward). Under these conditions, gravity waves with comparatively large eastward phase Speeds can pass the stratosphere and propagate to the lower thermosphere because their vertical wavelengths in the mesosphere are rather large which implies reduced dynamical stability. When finally breaking in the lower thermosphere, these waves drive an enhanced residual circulation that causes a cold and high-altitude mesopause. The conditions for a mesopause jump occur only in the Southern Hemisphere (SH) and are associated with the late breakdown of the polar vortex. Mesopause jumps are primarily, but not only, observed prior and close to solstice. We also show that during the onset of PMSE in the SH, stratospheric zonal winds are still eastward (up to 30 m/s), and that the onset is not closely related to the Transition of the stratospheric circulation.

  9. Building a culture of health: promoting healthy relationships and reducing teen dating violence.

    Science.gov (United States)

    Schubert, Kristin

    2015-02-01

    Our society is faced with an epidemic of partner violence that has far-reaching consequences. As viewed through a public health lens, prevention of teen dating violence can thwart this epidemic from starting and spreading. The Robert Wood Johnson Foundation's Culture of Health strategy aims to reduce negative outcomes and promotes overall well-being. This supplement affirms our dedication to a Culture of Health by generating an evidence base to prevent teen dating violence and promote healthy relationships across the life span.

  10. Teen use of a patient portal: a qualitative study of parent and teen attitudes.

    Science.gov (United States)

    Bergman, David A; Brown, Nancy L; Wilson, Sandra

    2008-01-01

    We conducted a qualitative study of the attitudes of teens and parents toward the use of a patient portal. We conducted two teen and two parent focus groups, one teen electronic bulletin board, and one parent electronic bulletin board. Videotapes and transcripts from the groups were independently analyzed by two reviewers for significant themes, which were then validated by two other members of the research team. Twenty-eight teens and 23 parents participated in the groups. Significant themes included issues about teens' control of their own healthcare; enthusiasm about the use of a patient portal to access their providers, seek health information, and make appointments; and concerns about confidentiality. In summary, there was considerable support among teens and parents for a patient portal as well as concerns about confidentiality. The teen portal affords an opportunity to negotiate issues of confidentiality.

  11. A Cafe Scientifique for Teens

    Science.gov (United States)

    Hall, M.; Mayhew, M.

    2008-12-01

    It is well-known to those pursuing the quest to connect scientists to the public that an exceedingly hard-to- reach demographic is people of high school age. Typically, kids may tag along with their parents to museums until they reach adolescence, and then don't again appear in museums until they themselves have children. We have addressed this demographic challenge for free-choice-learning by developing a Cafe Scientifique program specifically for high school students. The Cafe Scientifique model for adults was developed in England and France, and has now spread like wildfire across the U.S. Typically, people come to a informal setting like a cafe, socialize and have food and drink, and then hear a short presentation by a scientist on a hot science topic in the news. This is followed by a period of lively discussion. We have followed this model for high school age students in four towns in northern New Mexico--Los Alamos, Santa Fe, Espanola, and Albuquerque--which represent a highly diverse demographic. We started this novel project with some trepidation, i.e. what if we build it and they don't come. But the program has proven popular beyond our expectations in all four towns. A part of the secret of success is the social setting, and-especially for this age group-the food provided. But we have also found that the kids are genuinely interested in the science topics, directing their own program, and interacting with scientists. We have often heard statements like, "I think it is important to be well-informed citizens". One of the most important aspects of the Cafes for the kids is to be able to discuss and argue about issues related to the science topic with the presenter and each other. It is an important part of the popularity that the Cafes do not involve school or parents, but also that we have strived to give the kids ownership of the program. Each town has a Youth Leadership Team-open to any teen-that discusses and prioritizes potential topics, conducts

  12. The Right Start: City Trends. Conditions of Babies and Their Families in America's Largest Cities (1990-1998). Child Trends/KIDS COUNT Special Report.

    Science.gov (United States)

    Croan, Tara; Hatcher, Juliet; Jager, Justin; Long, Melissa; O'Hare, William; Wertheimer, Richard

    This report presents data for the nation's 50 largest cities for every year from 1990-98 on eight measures of a healthy start to life (teen births, repeat teen births, births to unmarried women, low maternal education, late or no prenatal care, smoking during pregnancy, low-birthweight births, and preterm births). It identifies cities that have…

  13. Media and Sex: Perspectives from Hispanic Teens

    Science.gov (United States)

    Johnston Polacek, Georgia N. L.; Rojas, Viviana; Levitt, Steven; Mika, Virginia Seguin

    2006-01-01

    Little is known about Hispanic teens' sexual knowledge, attitudes and behaviors and their relationship to media influences. Information about this relationship could contribute to an understanding of the early onset of sexual behavior and early teen pregnancy. This paper reports preliminary findings from a pilot project conducted to determine…

  14. Teen motherhood in cross-cultural perspective.

    Science.gov (United States)

    Kramer, Karen L; Lancaster, Jane B

    2010-01-01

    Teen motherhood is the prevalent childbearing pattern in most traditional populations. Yet early motherhood is associated with negative biological and social outcomes in the developed world. We review the teen pregnancy literature in light of this discrepancy, emphasizing two core debates. The first debate centers on whether teens have poor pregnancy outcomes compared to older women, and whether negative outcomes are biologically based. Second, we consider the debate over the confounding effects of socio-economic conditions associated with being young. When teens are considered as a group, results are inconsistent across studies. When teens are disaggregated by age, the strongest finding across studies is that biological risk is concentrated in only the youngest of mothers. Negative consequences are associated with teen motherhood not because of chronological age per se, but because of relative developmental maturity and the availability of non-maternal support. In most traditional societies as well as in some sectors of developed societies, teen motherhood occurs within the context of extended kin networks and is subsidized through reliable economic and childcare assistance. Child-rearing practices, rather than pregnancy per se, may explain much of the discrepancy in the prevalence, success and attitudes toward teen motherhood in traditional and developed societies.

  15. Preventing Repeat Teen Births PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2013-04-02

    This 60 second public service announcement is based on the April 2013 CDC Vital Signs report, which discusses repeat teen births and ways teens, parents and guardians, health care providers, and communities can help prevent them.  Created: 4/2/2013 by Centers for Disease Control and Prevention (CDC).   Date Released: 4/2/2013.

  16. Teen PACK: Population Awareness Campaign Kit.

    Science.gov (United States)

    Zero Population Growth, Inc., Washington, DC.

    This packet of instructional materials is designed to teach teenagers about the effects of overpopulation on the world and on the individual. Information is presented in three related booklets. The first of the three parts of the "Teen Population Awareness Campaign Kit," illustrates overpopulation through profiles of teens living in…

  17. Texts, Troubled Teens, and Troubling Times

    Science.gov (United States)

    Tatum, Alfred W., Ed.

    2009-01-01

    Seeking ways to effectively mediate texts with troubled teens in troubling times is worth the investment. Text is a powerful tool for shaping positive life trajectories, especially for those teens being affected by vulnerable-producing conditions that interrupt positive human development. These conditions, coupled with poor literacy skills…

  18. Teen Childbearing, Single Parenthood, and Father Involvement

    Science.gov (United States)

    ... by race/ethnicity. The proportion of recent teen mothers who are single is similar among non-Hispanic white and Hispanic ... is important to understand that, on average, teen mothers are at high risk for single parenthood and especially high risk of parenthood without ...

  19. Top Ten Myths and Realities of Working with Teen Volunteers.

    Science.gov (United States)

    Shoemaker, Kellie

    1998-01-01

    Discusses misconceptions about teen volunteers in public libraries: teens who hang out make good volunteers; teens who apply want to work; parents aren't important; incorporating volunteers is easy; enthusiasm means commitment; volunteers will tell you if they don't enjoy the job; non-performers are easy to fire; teens volunteer because they need…

  20. Teen Summer Reading Program, 1999. Read around the World.

    Science.gov (United States)

    Virginia State Library, Richmond.

    This guide for the 1999 Virginia teen summer reading program for public libraries, "Read around the World," includes the following chapters: (1) "Reading and Teens," including serving the underserved, tips for teens, and a recipe for choosing a book to read for fun; (2) "Programming and Teens," including "The Why…

  1. Reducing the Teen Death Rate. KIDS COUNT Indicator Brief

    Science.gov (United States)

    Shore, Rima; Shore, Barbara

    2009-01-01

    Life continues to hold considerable risk for adolescents in the United States. In 2006, the teen death rate stood at 64 deaths per 100,000 teens (13,739 teens) (KIDS COUNT Data Center, 2009). Although it has declined by 4 percent since 2000, the rate of teen death in this country remains substantially higher than in many peer nations, based…

  2. Bundles of Norms About Teen Sex and Pregnancy.

    Science.gov (United States)

    Mollborn, Stefanie; Sennott, Christie

    2015-09-01

    Teen pregnancy is a cultural battleground in struggles over morality, education, and family. At its heart are norms about teen sex, contraception, pregnancy, and abortion. Analyzing 57 interviews with college students, we found that "bundles" of related norms shaped the messages teens hear. Teens did not think their communities encouraged teen sex or pregnancy, but normative messages differed greatly, with either moral or practical rationalizations. Teens readily identified multiple norms intended to regulate teen sex, contraception, abortion, childbearing, and the sanctioning of teen parents. Beyond influencing teens' behavior, norms shaped teenagers' public portrayals and post hoc justifications of their behavior. Although norm bundles are complex to measure, participants could summarize them succinctly. These bundles and their conflicting behavioral prescriptions create space for human agency in negotiating normative pressures. The norm bundles concept has implications for teen pregnancy prevention policies and can help revitalize social norms for understanding health behaviors.

  3. Jumps of the eta invariant

    CERN Document Server

    Farber, M S; Farber, Michael S.; Levine, Jerome P.

    1994-01-01

    We study the eta-invariant, defined by Atiyah-Patodi-Singer a real valued invariant of an oriented odd-dimensional Riemannian manifold equipped with a unitary representation of its fundamental group. When the representation varies analytically, the corresponding eta-invariant may have an integral jump, known also as the spectral flow. The main result of the paper establishes a formula for this spectral jump in terms of the signatures of some homological forms, defined naturally by the path of representations. These signatures may also be computed by means of a spectral sequence of Hermitian forms,defined by the deformation data. Our theorem on the spectral jump has a generalization to arbitrary analytic families of self-adjoint elliptic operators. As an application we consider the problem of homotopy invariance of the rho-invariant. We give an intrinsic homotopy theoretic definition of the rho-invariant, up to indeterminacy in the form of a locally constant function on the space of unitary representations. In...

  4. Teens' risk of AIDS, unintended pregnancies examined.

    Science.gov (United States)

    Scommegna, P

    1996-08-01

    Approximately 1.6 billion of the world's population are 10-24 years old. About 15 million women aged 15-19 years give birth annually, more than 10% of all births worldwide. The proportion of teen births to unwed mothers has risen by 50% in the US since 1980, and by almost 70% in Kenya during the 1980s. Approximately 2 million adolescent women in developing countries have illegal, unsafe abortions each year, with at least 10% of all abortions worldwide occurring among women ages 15-19. Since the start of the HIV/AIDS pandemic, at least 12 million young people have been infected with HIV. In fact, about half of all HIV infections worldwide have occurred in young people under age 25. HIV is spreading rapidly among young women aged 15-24 such that in many countries women account for 40% of all new HIV infections. Several new reports from the Population Reference Bureau, the US Census Bureau, and the International Center for Research on Women offer data on how the world's youth are exposed to unintended pregnancies, unsafe abortions, and sexually transmitted diseases. Maternal and infant mortality among adolescent mothers and their children, coercion to have sex, and the growing proportion of school-aged youth worldwide enrolled in secondary schools are discussed.

  5. Price jumps on European stock markets

    Directory of Open Access Journals (Sweden)

    Jan Hanousek

    2014-03-01

    Full Text Available We analyze the dynamics of price jumps and the impact of the European debt crisis using the high-frequency data reported by selected stock exchanges on the European continent during the period January 2008 to June 2012. We employ two methods to identify price jumps: Method 1 minimizes the probability of false jump detection (the Type-II Error-Optimal price jump indicator and Method 2 maximizes the probability of successful jump detection (the Type-I Error-Optimal price jump indicator. We show that individual stock markets exhibited differences in price jump intensity before and during the crisis. We also show that in general the variance of price jump intensity could not be distinguished as different in the pre-crisis period from that during the crisis. Our results indicate that, contrary to common belief, the intensity of price jumps does not uniformly increase during a period of financial distress. However, there do exist differences in price jump dynamics across stock markets and investors have to model emerging and mature markets differently to properly reflect their individual dynamics.

  6. Pricing Asian power options under jump-fraction process

    Directory of Open Access Journals (Sweden)

    Bin Peng

    2012-12-01

    Full Text Available A framework for pricing Asian power options is developed when the underlying asset follows a jump-fraction process. The partial differential equation (PDE in the fractional environment with jump is constructed for such option using general Itô's lemma and self-financing dynamic strategy. With the boundary condition, an analytic formula for the option with geometric average starting at any time before maturity is derived by solving the PDE, and the option with arithmetic average is evaluated in Monte Carlo simulation using control variate technique with the help of the above analytic solution. Overwhelming numerical evidence indicates that the technique proposed is computationally efficient and dramatically improves the accuracy of the simulated price. Moreover, this study will pave a novel way to copy with the option contracts based on thinly-traded assets like oil, or currencies or interest rates.

  7. BIOMECHANICAL ANALYSIS OF RUNNING IN THE HIGH JUMP

    Directory of Open Access Journals (Sweden)

    Leite Werlayne

    2013-02-01

    Full Text Available The aim of this paper is to analyze the biomechanics of running at high jump. To this study was realized a bibliographic revision. The running phase is the one which starts when the athlete is set in movement for the jump until the moment that he touches the ground with the takeoff foot in front of the bar, this phase can be divided into two parts: the running in straight line and the running in curve. On the other hand, for better understanding and due to a biomechanical complexity, the running in curve will be divided into three other parts: the three last strides, the two last strides and the last strides. Besides that, we could mention important factors for an efficient approach run: the radius of the curve, the distance and length of the takeoff run.

  8. Teens and Mobile Phones: Text Messaging Explodes as Teens Embrace It as the Centerpiece of Their Communication Strategies with Friends

    Science.gov (United States)

    Lenhart, Amanda; Ling, Rich; Campbell, Scott; Purcell, Kristen

    2010-01-01

    Daily text messaging among American teens has shot up in the past 18 months, from 38% of teens texting friends daily in February of 2008 to 54% of teens texting daily in September 2009. And it's not just frequency--teens are sending enormous quantities of text messages a day. Half of teens send 50 or more text messages a day, or 1,500 texts a…

  9. Reducing the stigmatization of teen mothers.

    Science.gov (United States)

    SmithBattle, Lee I

    2013-01-01

    Teen mothers are stigmatized by stereotypes that they are unmotivated, irresponsible, and incompetent parents. In spite of the pervasiveness of these stereotypes, stigma is rarely described as a contributing factor to teen mothers' difficulties and their health and social disparities. After tracing how teen mothers have been misrepresented and stereotyped over the last half century, I describe what is known about the stigma associated with teen mothering, reasons for its persistence, efforts to reduce it, and its potentially harmful effects. Stigma should be of concern to nurses because stigmatizing practices impede effective clinical care, contribute to teen mothers' many challenges, and violate the nursing ethic that patients be treated with respect and dignity. Recommendations for restoring dignity and reducing stigma in healthcare focus on developing recognition practices that are predicated on respect and concern for the teen's well-being and her capacity as a mother. Nurses are also urged to advocate for services and policies that reduce the stigmatization and marginalization of teen mothers.

  10. Bilateral contact ground reaction forces and contact times during plyometric drop jumping.

    Science.gov (United States)

    Ball, Nick B; Stock, Christopher G; Scurr, Joanna C

    2010-10-01

    Drop jumping (DJ) is used in training programs aimed to improve lower extremity explosive power. When performing double-leg drop jumps, it is important to provide an equal stimulus to both legs to ensure balanced development of the lower legs. The aim of this study was to bilaterally analyze the ground reactions forces and temporal components of drop jumping from 3 heights. Ten recreationally active male subjects completed 3 bounce-drop jumps from 3 starting heights (0.2, 0.4, and 0.6 m). Two linked force platforms were used to record left- and right-leg peak vertical force, time to peak force, average force, ground contact time, impulse and time differential. Between-height and between-leg comparisons for each variable were made using a multivariate analysis of variance with post hoc Wilcoxon tests (p vertical forces and temporal components occur; however, shorter contact times were found at the lower heights.

  11. Taking a Teen Pregnancy Prevention Program to the Home: The AIM 4 Teen Moms Experience.

    OpenAIRE

    Subuhi Asheer; Ellen Kisker

    2014-01-01

    This report discusses findings from the first 18 months of a program implementation evaluation of AIM 4 Teen Moms, a teen pregnancy intervention designed to delay rapid repeat pregnancies among parenting teen mothers in Los Angeles. The program is delivered primarily in participants' homes. The report describes the program's development and design, recruiting approach, facilitators' training in and delivery of the program, and youth engagement and response, concluding with lessons for future ...

  12. A Content Analysis of Teen Parenthood in "Teen Mom" Reality Programming.

    Science.gov (United States)

    Martins, Nicole; Malacane, Mona; Lewis, Nicky; Kraus, Ashley

    2016-12-01

    A content analysis of the MTV shows 16 and Pregnant (n = 59), Teen Mom (n = 20), and Teen Mom 2 (n = 20) was conducted to determine whether these programs accurately portray teen pregnancy. The results revealed that teen mothers on 16 and Pregnant were younger, more often White, and had more healthy babies as compared to national averages. The babies' fathers were more involved in the daily care of their child as compared to reality. Medical insurance or receipt of government assistance was almost never discussed. Teen mothers in the Teen Mom shows were significantly more likely to achieve a high school diploma as compared to reality. Finally, mothers on Teen Mom and Teen Mom 2 were significantly less likely to voice concern about finances and had more active social lives than mothers on 16 and Pregnant. Using social learning theory as a theoretical framework, we argue that these shows provide mixed messages to young audiences about teen pregnancy and parenthood.

  13. Fast unilateral isometric knee extension torque development and bilateral jump height.

    Science.gov (United States)

    de Ruiter, Cornelis J; Van Leeuwen, Daniel; Heijblom, Arjan; Bobbert, Maarten F; de Haan, Arnold

    2006-10-01

    We hypothesized that the initial rate (first 40 ms) of unilateral knee extensor torque development during a maximally fast isometric contraction would depend on the subjects' ability for fast neural activation and that it would predict bilateral jumping performance. Nine males (21.8 +/- 0.9 yr, means +/- SD) performed unilateral fast isometric knee extensions (120 degrees knee angle) without countermovement on a dynamometer and bilateral squat jumps (SJ) and countermovement jumps (CMJ) starting from 90 and 120 degrees knee angles (full extension = 180 degrees ). The dynamometer contractions started either from full relaxation or from an isometric pre-tension (15% maximal isometric torque, Tmax). Torque time integral for the first 40 ms after torque onset (TTI-40, normalized to Tmax) and averaged normalized rectified knee extensor EMG for 40 ms before fast torque onset (EMG-40) were used to quantify initial torque rise and voluntary muscle activation. TTI-40 without pre-tension (range: 0.02-0.19% Tmax per second) was significantly lower than TTI-40 with pre-tension, and both were significantly (r = 0.81 and 0.80) related to EMG-40. During jumping, similar significant positive relations were found between jump height and knee extensor EMG during the first 100 ms of the rise in ground reaction force. There also were significant positive linear relations between dynamometer TTI-40 and jump height (r = 0.75 (SJ 90), 0.84 (SJ 120), 0.76 (CMJ 90), and 0.86 (CMJ 120)) but not between dynamometer Tmax and jump height (-0.16 < r < 0.02). One-legged TTI-40 to a large extent explained the variation in jump height. The ability to produce a high efferent neural drive before muscle contraction seemed to dominate performance in both the simple single-joint isometric task and the complex multijoint dynamic task.

  14. Δ-matroid and jump system

    Directory of Open Access Journals (Sweden)

    Santosh N. Kabadi

    2005-01-01

    Full Text Available The concept of Δ-matroid is a nontrivial, proper generalization of the concept of matroid and has been further generalized to the concept of jump system. In this paper, we show that jump systems are, in some sense, equivalent to Δ-matroids. Using this equivalence and the Δ-matroid theory, we give simple proofs and extensions of many of the results on jump systems.

  15. Time change, jumping measure and Feller measure

    OpenAIRE

    He, Ping

    2007-01-01

    In this paper, we shall investigate some potential theory for time change of Markov processes. Under weak duality, it is proved that the jumping measure and Feller measure are actually independent of time change, and the jumping measure of a time changed process induced by a PCAF supported on $V$ coincides with the sum of the Feller measure on $V$ and the trace of the original jumping measure on $V$.

  16. The aerodynamics of jumping rope

    Science.gov (United States)

    Aristoff, Jeffrey; Stone, Howard

    2011-03-01

    We present the results of a combined theoretical and experimental investigation of the motion of a rotating string that is held at both ends (i.e. a jump rope). In particular, we determine how the surrounding fluid affects the shape of the string at high Reynolds numbers: the string bends toward the axis of rotation, thereby reducing its total drag. We derive a pair of coupled non-linear differential equations that describe the shape, the numerical solution of which compares well with asymptotic approximations and experiments. Implications for successful skipping will be discussed.

  17. Dynamic jump intensities and risk premiums

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Ornthanalai, Chayawat; Jacobs, Kris

    2012-01-01

    We build a new class of discrete-time models that are relatively easy to estimate using returns and/or options. The distribution of returns is driven by two factors: dynamic volatility and dynamic jump intensity. Each factor has its own risk premium. The models significantly outperform standard...... models without jumps when estimated on S&P500 returns. We find very strong support for time-varying jump intensities. Compared to the risk premium on dynamic volatility, the risk premium on the dynamic jump intensity has a much larger impact on option prices. We confirm these findings using joint...... estimation on returns and large option samples....

  18. Laminar circular hydraulic jumps without separation

    Science.gov (United States)

    Dasgupta, Ratul; Tomar, Gaurav; Govindarajan, Rama

    2009-11-01

    The traditional inviscid criterion for the occurrence of a planar, standing hydraulic jump is to have the Froude number decrease downstream and go through a value of 1 at some location. Here, upstream propagating, small-amplitude, long, non-dispersive gravity waves are trapped, and non-linear steepening is said to result in a near-discontinuous height profile, but it is not clear how. Such a condition on the Froude number is shown in the present axisymmetric Navier-Stokes computations to hold for a circular jump as well. The relevance of non-linear steepening to a circular jump is therefore a question we wish to answer. In circular jumps, moreover, a region of recirculation is usually observed underneath the jump, underlining the importance of viscosity in this process. This led Tani (J. Phys. Soc. Japan, 1949) to hypothesise that boundary-layer separation was the cause of the circular jump. This hypothesis has been debated extensively and the possibility of circular jumps without separation hinted at. In our simulations, we are able to obtain circular hydraulic jumps without any flow separation. This, and the necessity or otherwise of viscosity in jump formation will be discussed.

  19. A Molecular Jump Mechanism of Water Reorientation

    National Research Council Canada - National Science Library

    Damien Laage; James T. Hynes

    2006-01-01

    .... This water reorientation mechanism involves large-amplitude angular jumps, rather than the commonly accepted sequence of small diffusive steps, and therefore calls for reinterpretation of many...

  20. Kinematics and Kinetics of Squats, Drop Jumps and Imitation Jumps of Ski Jumpers.

    Science.gov (United States)

    Pauli, Carole A; Keller, Melanie; Ammann, Fabian; Hübner, Klaus; Lindorfer, Julia; Taylor, William R; Lorenzetti, Silvio

    2016-03-01

    Squats, drop jumps, and imitation jumps are commonly used training exercises in ski jumping to enhance maximum force, explosive force, and sport-specific skills. The purpose of this study was to evaluate the kinetics and kinematics of training exercises in ski jumping and to find objective parameters in training exercises that most correlate with the competition performance of ski jumpers. To this end, barbell squats, drop jumps, and imitation jumps were measured in a laboratory environment for 10 elite ski jumpers. Force and motion data were captured, and the influence of maximum vertical force, force difference, vertical take-off velocity, knee moments, knee joint power, and a knee valgus/varus index was evaluated and correlated with their season jump performance. The results indicate that, especially for the imitation jumps, a good correlation exists between the vertical take-off velocity and the personal jump performance on the hill (R = 0.718). Importantly, however, the more the athletes tended toward a valgus knee alignment during the measured movements, the worse their performance (R = 0.729 imitation jumps; R = 0.685 squats). Although an evaluation of the athletes' lower limb alignment during competitive jumping on the hill is still required, these preliminary data suggest that performance training should additionally concentrate on improving knee alignment to increase ski jumping performance.

  1. Facts at a Glance: [Report on 1992 Data on Teen Fertility in the United States].

    Science.gov (United States)

    Moore, Kristin, Comp.; And Others

    This fact sheet contains data on teen pregnancy. The folowing information is provided: teen birth rate, 1960-1992; number of births to teens, 1960-1992; percent of non-marital teen births, 1960-1992; births to unmarried women, by age group, 1992; international comparison on teen birth rate; abortion rate among U.S. teens, 1973-1990; pregnancy…

  2. Help your teen cope with stress

    Science.gov (United States)

    Adolescents - stress; Anxiety - cope with stress ... Common sources of stress in teens include: Worrying about schoolwork or grades Juggling responsibilities, such as school and work or sports Having problems ...

  3. Especially for Teens: You and Your Sexuality

    Science.gov (United States)

    ... a person is transgender. Transgender teens may face bullying or discrimination. Some may feel scared and alone. ... a stranger. What is intimate partner violence? This type of violence occurs between couples in same-sex ...

  4. Why Is My Voice Changing? (For Teens)

    Science.gov (United States)

    ... Week of Healthy Breakfasts Shyness Why Is My Voice Changing? KidsHealth > For Teens > Why Is My Voice ... deeper than a girl's, though. What Causes My Voice to Change? At puberty, guys' bodies begin producing ...

  5. [Video games, a therapeutic mediator for teens].

    Science.gov (United States)

    Nickler, Christophe

    2015-10-01

    Teenagers love video games and other multimedia tools. Sometimes they love them too much, leading to addictive use. A child psychiatry team in Nancy has developed a therapeutic multimedia workshop to contribute to treating teens.

  6. Parent's Guide to Surviving the Teen Years

    Science.gov (United States)

    ... and who they may be communicating with online. Teens shouldn't have unlimited access to TV or the Internet in private — these should be public activities. Access to technology also should be limited after certain hours (for ...

  7. Teens, Health and Technology: A National Survey

    National Research Council Canada - National Science Library

    Ellen Wartella; Vicky Rideout; Heather Montague; Leanne Beaudoin-Ryan; Alexis Lauricella

    2016-01-01

      In the age of digital technology, as teens seem to be constantly connected online, via social media, and through mobile applications, it is no surprise that they increasingly turn to digital media...

  8. Anesthesia -- What to Expect (For Teens)

    Science.gov (United States)

    ... variety of modern medications and extremely capable monitoring technology to ensure that people are stable and as comfortable as possible before, during, ... For Teens For Kids For Parents MORE ON THIS TOPIC ...

  9. Teen Violence Can Be Contagious, Study Contends

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_162646.html Teen Violence Can Be Contagious, Study Contends Preventive programs ... such as happiness, obesity and smoking spread within social networks. "We now have evidence that shows how important ...

  10. Talking to your teen about drinking

    Science.gov (United States)

    ... begin talking with your teen about drugs and alcohol is now. Children as young as 9 years old may become curious about drinking and they may try alcohol. By Saying Nothing, you are Saying Something Saying ...

  11. Dysfunctional Uterine Bleeding (DUB) (For Teens)

    Science.gov (United States)

    ... the Right Sport for You Shyness Abnormal Uterine Bleeding (AUB) KidsHealth > For Teens > Abnormal Uterine Bleeding (AUB) ... español Hemorragia uterina disfuncional What Is Abnormal Uterine Bleeding? Abnormal uterine bleeding (AUB) is the name doctors ...

  12. Bipolar Disorder in Children and Teens

    Science.gov (United States)

    ... is in crisis. What do I do? Share Bipolar Disorder in Children and Teens Download PDF Download ... brochure will give you more information. What is bipolar disorder? Bipolar disorder is a serious brain illness. ...

  13. Teen Safety: Putting an End to Bullying

    Science.gov (United States)

    ... Print Share Teen Safety: Putting An End to Bullying Page Content Article Body The outbreak of school ... that has been allowed to go virtually unchecked: bullying. It turns out that many of these adolescent ...

  14. When Your Teen Is Having a Baby

    Science.gov (United States)

    ... smokes or uses alcohol or other drugs, her health care provider can offer ways to help her quit. Nutrition Fast food, soft drinks, sweets — teen diets are notoriously unbalanced. Eating well ...

  15. Teens and Steroids: A Dangerous Combo

    Science.gov (United States)

    ... boys who are “late bloomers” or to stimulate growth among teens who are failing to grow. Some may be dealing with unscrupulous clinics or street dealers on the black market. Unfortunately, a number of vendors sell anabolic steroids ...

  16. When Your Teen Is Having a Baby

    Science.gov (United States)

    ... your teen or using threats is likely to backfire in the long run. There's no "one size ... to deal with some of the uncomfortable side effects of pregnancy, like nausea and vomiting Knowing what ...

  17. About BMI for Children and Teens

    Science.gov (United States)

    ... Nutrition Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs About Child & Teen ... Nutrition Physical Activity Overweight & Obesity Healthy Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Language: English Español ( ...

  18. Sexual Harassment and Sexual Bulllying (For Teens)

    Science.gov (United States)

    ... Can I Help Someone Who's Being Bullied? Volunteering Sexual Harassment and Sexual Bullying KidsHealth > For Teens > Sexual Harassment and Sexual ... is being sexually harassed or bullied. What Are Sexual Bullying and Harassment? Just like other kinds of ...

  19. Drive Alive: Teen Seat Belt Survey Program

    OpenAIRE

    Burkett, Katie M.; Davidson, Steve; Cotton, Carol; Barlament, James; Loftin, Laurel; Stephens, James; Dunbar, Martin; Butterfield, Ryan

    2010-01-01

    Objective: To increase teen seat belt use among drivers at a rural high school by implementing the Drive Alive Pilot Program (DAPP), a theory-driven intervention built on highway safety best practices. Methods: The first component of the program was 20 observational teen seat belt surveys conducted by volunteer students in a high school parking lot over a 38-month period before and after the month-long intervention. The survey results were published in the newspaper. The second compo...

  20. Adolescents' perceptions of popular teen magazines.

    Science.gov (United States)

    Chow, Jean

    2004-10-01

    The mass media has an enormous influence on adolescent women and their perceptions about the world and themselves. Teen magazines are a favoured form of the mass media, thus they were chosen for this research project. The aim of this paper is to report a study exploring the messages of health and health-related material in teen magazines from the perspective of adolescents. Knowledge of how adolescents perceive teen magazine messages can be used in the care of this client group. Interpretive inquiry, a substantively driven research approach, was used for the project. A convenience sample of 12 adolescents, aged 12-18 years, participated in two focus groups, and selected images and texts from popular North American teen magazines (YM, Teen, and Seventeen) to discuss. Focus group discussions were audiotaped and then transcribed. Individual interviews with the adolescents were also completed to obtain additional data. Audiotaped interviews were analysed using Gadamer's hermeneutic ideas about 'claim' or 'address'. The findings indicate that teen magazines promote particular expectations about health and health-related activities. Participants noted that the magazines promote the message of perfection by portraying models with perfect eyes, teeth and bodies. The magazines provide ideals of thinness which are presented in a seemingly attainable fashion. Participants stated that magazines suggest that adolescent women need male attention for protection and companionship, in order to achieve fulfillment. Being healthy or whole seemed to be dependent on the adolescent reader embracing and becoming the ideals portrayed in teen magazines. In order to provide relevant and sensitive health care, health care providers need to be cognizant of the persistent demands placed on adolescents by teen magazines and the mass media in general. Media messages and their influences need to be discussed with adolescents, either in school health programmes or clinician visits.

  1. Vital Signs-Preventing Teen Pregnancy

    Centers for Disease Control (CDC) Podcasts

    2015-04-07

    This podcast is based on the April 2015 CDC Vital Signs report. Teen births in the U.S. have declined, but still, more than 273,000 infants were born to teens ages 15 to 19 in 2013. Learn about the most effective types of birth control.  Created: 4/7/2015 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/7/2015.

  2. Teens, Health and Technology: A National Survey

    Directory of Open Access Journals (Sweden)

    Ellen Wartella

    2016-06-01

    Full Text Available In the age of digital technology, as teens seem to be constantly connected online, via social media, and through mobile applications, it is no surprise that they increasingly turn to digital media to answer their health questions. This study is the first of its kind to survey a large, nationally-representative sample of teens to investigate how they use the newest digital technologies, including mobile apps, social networking sites, electronic gaming and wearable devices, to explore health topics. The survey covered the types of health topics teens most frequently search for, which technologies they are most likely to use and how they use them, and whether they report having changed their behaviors due to digital health information. In addition, this survey explores how the digital divide continues to impact adolescents. Results of this study indicate that teens are concerned about many health issues, ranging from fitness, sexual activity, drugs, hygiene as well as mental health and stress. As teens virtually always have a digital device at their fingertips, it is clear that public health interventions and informational campaigns must be tailored to reflect the ways that teens currently navigate digital health information and the health challenges that concern them most.

  3. Teens, Health and Technology: A National Survey

    Directory of Open Access Journals (Sweden)

    Ellen Wartella

    2016-06-01

    Full Text Available In the age of digital technology, as teens seem to be constantly connected online, via social media, and through mobile applications, it is no surprise that they increasingly turn to digital media to answer their health questions. This study is the first of its kind to survey a large, nationally-representative sample of teens to investigate how they use the newest digital technologies, including mobile apps, social networking sites, electronic gaming and wearable devices, to explore health topics. The survey covered the types of health topics teens most frequently search for, which technologies they are most likely to use and how they use them, and whether they report having changed their behaviors due to digital health information. In addition, this survey explores how the digital divide continues to impact adolescents. Results of this study indicate that teens are concerned about many health issues, ranging from fitness, sexual activity, drugs, hygiene as well as mental health and stress. As teens virtually always have a digital device at their fingertips, it is clear that public health interventions and informational campaigns must be tailored to reflect the ways that teens currently navigate digital health information and the health challenges that concern them most.

  4. Electroencephalographic recordings during parachute jump sessions.

    Science.gov (United States)

    Gauthier, P; Jouffray, L; Rodi, M; Gottesmann, C

    1980-04-01

    Electroencephalographic (EEG) recordings of experienced parachutists were done by means of telemetry before, during, and after jumps of up to 3500m. During free-fall and after stabilization, alpha rhythm was recorded from several alpha reactive subjects when they closed their eyes. No pathological EEG recordings were obtained during the different phases of the jump.

  5. Jump Detection in the Danish Stock Market

    DEFF Research Database (Denmark)

    Høg, Esben

    2002-01-01

    It is well known in financial economics that stock market return data are often modelled by a diffusion process with some regular drift function. Occasionally, however, sudden changes or jumps occur in the return data. Wavelet scaling methods are used to detect jumps and cusps in stock market...

  6. Rope Jumping: A Preliminary Developmental Study.

    Science.gov (United States)

    Wickstrom, Ralph L.

    The basic movement pattern used in skilled individual rope jumping performance was determined and used as a model against which to evaluate the rope jumping form used by children at various levels of skills development. The techniques of adults and nursery school children were filmed and analyzed. The specific causes of unsuccessful attempts were…

  7. Separation and pattern formation in hydraulic jumps

    DEFF Research Database (Denmark)

    Bohr, Tomas; Ellegaard, C.; Hansen, A. Espe;

    1998-01-01

    We present theory and experiments on the circular hydraulic jump in the stationary regime. The theory can handle the situation in which the fluid flows over an edge far away from the jump. In the experiments the external height is controlled, and a series of transitions in the flow structure appe...

  8. Internal hydraulic jumps with large upstream shear

    Science.gov (United States)

    Ogden, Kelly; Helfrich, Karl

    2015-11-01

    Internal hydraulic jumps in approximately two-layered flows with large upstream shear are investigated using numerical simulations. The simulations allow continuous density and velocity profiles, and a jump is forced to develop by downstream topography, similar to the experiments conducted by Wilkinson and Wood (1971). High shear jumps are found to exhibit significantly more entrainment than low shear jumps. Furthermore, the downstream structure of the flow has an important effect on the jump properties. Jumps with a slow upper (inactive) layer exhibit a velocity minimum downstream of the jump, resulting in a sub-critical downstream state, while flows with the same upstream vertical shear and a larger barotropic velocity remain super-critical downstream of the jump. A two-layer theory is modified to account for the vertical structure of the downstream density and velocity profiles and entrainment is allowed through a modification of the approach of Holland et al. (2002). The resulting theory can be matched reasonably well with the numerical simulations. However, the results are very sensitive to how the downstream vertical profiles of velocity and density are incorporated into the layered model, highlighting the difficulty of the two layer approximation when the shear is large.

  9. Strong jump traceability and Demuth randomness

    CERN Document Server

    Greenberg, Noam

    2011-01-01

    We solve the covering problem for Demuth randomness, showing that a computably enumerable set is computable from a Demuth random set if and only if it is strongly jump-traceable. We show that on the other hand, the class of sets which form a base for Demuth randomness is a proper subclass of the class of strongly jump-traceable sets.

  10. Teen Stress: How To Cope, An Accompanying Manual for the Teen Stress Video.

    Science.gov (United States)

    Trotter, Jennie C.

    Today's teens are dealing with an increasing amount of stress, but they have developed few positive stress management skills. Strategies that students can use to deal with their daily stressors are covered in this manual, which was designed as a companion volume to a teen stress video. The material here addresses many of the issues faced during…

  11. Teens Will Be Teens: The Latest Brain Research Has a Lot to Say about Adolescent Behavior

    Science.gov (United States)

    Jones, Jami

    2005-01-01

    Most adults are challenged when it comes to understanding teens' motives. "What were they thinking of?" is an all-too-common response. Without a doubt, no developmental period in life is more confounding and baffling than adolescence. Until recently, erratic teen behavior was blamed on raging hormones, but scientific research in the last decade…

  12. The Teen Depression Awareness Project: Building an Evidence Base for Improving Teen Depression Care. Research Highlights

    Science.gov (United States)

    Adamson, David M.

    2010-01-01

    Depression's effects on adolescent functioning and family burden are not well understood; there is also limited understanding of teens' and parents' attitudes and knowledge about depression, how these and other factors influence readiness for treatment, and the barriers to care that teens and their parents encounter. To address these knowledge…

  13. Real Teens, Real Tours: Teen Engagement Strategies for the One-Time Visit

    Science.gov (United States)

    Kusuma, Krista Dahl; Wyrick, Gabrielle

    2014-01-01

    The teen behavior typically exhibited in school visit groups is often read by museum teachers as resistance or disengagement, when the opposite is more likely the case. This paper attempts to dispel some of the myths around teen behavior and serve as a practical guide to museum educators who desire a deeper, more successful engagement with teen…

  14. Real Teens, Real Tours: Teen Engagement Strategies for the One-Time Visit

    Science.gov (United States)

    Kusuma, Krista Dahl; Wyrick, Gabrielle

    2014-01-01

    The teen behavior typically exhibited in school visit groups is often read by museum teachers as resistance or disengagement, when the opposite is more likely the case. This paper attempts to dispel some of the myths around teen behavior and serve as a practical guide to museum educators who desire a deeper, more successful engagement with teen…

  15. Attitudes toward teen mothers among nursing students and psychometric evaluation of Positivity Toward Teen Mothers scale.

    Science.gov (United States)

    Kim, Son Chae; Burke, Leanne; Sloan, Chris; Barnett, Shannon

    2013-09-01

    To prepare future nurses who can deliver high quality nursing care to teen mothers, a better understanding of the nursing students' perception of teen mothers is needed. A descriptive cross-sectional study was conducted among 228 nursing students to evaluate the psychometric properties of the Positivity Toward Teen Mothers (PTTM) scale, to explore nursing students' general empathy and attitudes toward teen mothers, and to investigate the predictors of nursing students' attitudes toward teen mothers. Principal component factor analysis with varimax rotation resulted in a 19-item PTTM-Revised scale with Non-judgmental and Supportive subscales. Cronbach's alphas for the subscales were 0.84 and 0.69, respectively, and 0.87 for the total scale. Simultaneous multiple regression models showed that general empathy and having a teen mother in the family or as an acquaintance were significant predictors of positive attitudes toward teen mothers, whereas age was a significant negative predictor. The PTTM-Revised scale is a promising instrument for assessing attitudes toward teen mothers. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Parental perceptions of teen driving: Restrictions, worry and influence.

    Science.gov (United States)

    Jewett, Amy; Shults, Ruth A; Bhat, Geeta

    2016-12-01

    Parents play a critical role in preventing crashes among teens. Research of parental perceptions and concerns regarding teen driving safety is limited. We examined results from the 2013 Summer ConsumerStyles survey that queried parents about restrictions placed on their teen drivers, their perceived level of "worry" about their teen driver's safety, and influence of parental restrictions regarding their teen's driving. We produced frequency distributions for the number of restrictions imposed, parental "worry," and influence of rules regarding their teen's driving, reported by teen's driving license status (learning to drive or obtained a driver's license). Response categories were dichotomized because of small cell sizes, and we ran separate log-linear regression models to explore whether imposing all four restrictions on teen drivers was associated with either worry intensity ("a lot" versus "somewhat, not very much or not at all") or perceived influence of parental rules ("a lot" versus "somewhat, not very much or not at all"). Among the 456 parent respondents, 80% reported having restrictions for their teen driver regarding use of safety belts, drinking and driving, cell phones, and text messaging while driving. However, among the 188 parents of licensed teens, only 9% reported having a written parent-teen driving agreement, either currently or in the past. Worrying "a lot" was reported less frequently by parents of newly licensed teens (36%) compared with parents of learning teens (61%). Parents report having rules and restrictions for their teen drivers, but only a small percentage formalize the rules and restrictions in a written parent-teen driving agreement. Parents worry less about their teen driver's safety during the newly licensed phase, when crash risk is high as compared to the learning phase. Further research is needed into how to effectively support parents in supervising and monitoring their teen driver. Published by Elsevier Ltd.

  17. Stochastic stability properties of jump linear systems

    Science.gov (United States)

    Feng, Xiangbo; Loparo, Kenneth A.; Ji, Yuandong; Chizeck, Howard J.

    1992-01-01

    Jump linear systems are defined as a family of linear systems with randomly jumping parameters (usually governed by a Markov jump process) and are used to model systems subject to failures or changes in structure. The authors study stochastic stability properties in jump linear systems and the relationship among various moment and sample path stability properties. It is shown that all second moment stability properties are equivalent and are sufficient for almost sure sample path stability, and a testable necessary and sufficient condition for second moment stability is derived. The Lyapunov exponent method for the study of almost sure sample stability is discussed, and a theorem which characterizes the Lyapunov exponents of jump linear systems is presented.

  18. A review on the basketball jump shot.

    Science.gov (United States)

    Okazaki, Victor H A; Rodacki, André L F; Satern, Miriam N

    2015-06-01

    The ability to shoot an effective jump shot in the sport of basketball is critical to a player's success. In an attempt to better understand the aspects related to expert performance, researchers have investigated successful free throws and jump shots of various basketball players and identified movement variables that contribute to their success. The purpose of this study was to complete a systematic review of the scientific literature on the basketball free throw and jump shot for the purpose of revealing the critical components of shooting that coaches, teachers, and players should focus on when teaching, learning, practising, and performing a jump shot. The results of this review are presented in three sections: (a) variables that affect ball trajectory, (b) phases of the jump shot, and

  19. Usefulness of the jump-and-reach test in assessment of vertical jump performance.

    Science.gov (United States)

    Menzel, Hans-Joachim; Chagas, Mauro H; Szmuchrowski, Leszek A; Araujo, Silvia R; Campos, Carlos E; Giannetti, Marcus R

    2010-02-01

    The objective was to estimate the reliability and criterion-related validity of the Jump-and-Reach Test for the assessment of squat, countermovement, and drop jump performance of 32 male Brazilian professional volleyball players. Performance of squat, countermovement, and drop jumps with different dropping heights was assessed on the Jump-and-Reach Test and the measurement of flight time, then compared across different jump trials. The very high reliability coefficients of both assessment methods and the lower correlation coefficients between scores on the assessments indicate a very high consistency of each method but only moderate covariation, which means that they measure partly different items. As a consequence, the Jump-and-Reach Test has good ecological validity in situations when reaching height during the flight phase is critical for performance (e.g., basketball and volleyball) but only limited accuracy for the assessment of vertical impulse production with different jump techniques and conditions.

  20. Choose Health Action Teens: A Review of a Teens as Teachers Nutritional Education Training Curriculum

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Flesch

    2016-12-01

    Full Text Available This review draws from published research related to the best practices for the utilization of teens as teachers to examine Choose Health Action Teens (CHAT, a teen’s as teachers (TAT training curriculum.  Research shows that there are various components necessary to build a high quality TAT program.  Most of these components fall under four areas in which training is necessary for teens and adults: Teaching strategies, youth/child development, subject matter to be taught, and youth-adult partnerships.  These four areas provide a framework to review the Choose Health Action Teens (CHAT (Crosiar & Wolfe, 2013 teens as teachers training program curriculum.

  1. Jumping from the Brooklyn Bridge.

    Science.gov (United States)

    Kurtz, R J; Pizzi, W F; Richman, H; Tiefenbrun, J

    1987-07-01

    In an attempt to identify factors contributing to survival of free fall and impact, we evaluated the records of four patients who survived a jump from the Brooklyn Bridge into the East River in New York Harbor between 1977 and 1985. All four patients were male and ranged in age from 22 to 67 years. They had free falls of between 41.0 and 48.8 meters. All of the patients were brought to the hospital within 24 minutes of entering the water. Three of the four had emergency surgical treatment and the fourth patient had only minor injuries. All four patients survived the suicide attempts. The length of the hospital stay ranged from two to 26 days.

  2. Body Mass Index: Calculator for Child and Teen

    Science.gov (United States)

    ... About CDC.gov . DNPAO Home Division Information Nutrition Physical Activity Overweight and Obesity Healthy Weight Assessing Your Weight Body Mass Index (BMI) About Adult BMI Adult BMI Calculator About Child Teen BMI Child & Teen BMI Calculator Children's BMI ...

  3. Food Safety and Nutrition Information for Kids and Teens

    Science.gov (United States)

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Food Home Food Resources for You Consumers Kids & Teens ... More sharing options Linkedin Pin it Email Print Food Safety & Nutrition Information for Kids and Teens Fun & ...

  4. U.S. Teen Births Hit Historic Low: CDC

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_166083.html U.S. Teen Births Hit Historic Low: CDC Data from 2014 also ... 2017 TUESDAY, May 30, 2017 (HealthDay News) -- Teen births continue to decline in the United States, with ...

  5. U.S. Teens Lag on Recommended Vaccinations

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163435.html U.S. Teens Lag on Recommended Vaccinations HPV and flu ... at risk, according to a leading group of U.S. pediatricians. Teens' rates of vaccination against human papillomavirus ( ...

  6. 10 Ways to Help Your Teen Succeed in High School

    Science.gov (United States)

    ... bedtime to turn off the phone and limit video games and TV. previous continue 5. Instill Organizational Skills ... to show you're interested in your teen's education. Keep in mind, though, that while some teens ...

  7. Meningococcal Disease: Information for Teens and College Students

    Science.gov (United States)

    ... Size Email Print Share Meningococcal Disease: Information for Teens and College Students Page Content ​ Meningococcal disease is ... receive the vaccine. Which vaccines are recommended for teens and young adults? Meningococcal conjugate vaccines (MCV4) Preteens ...

  8. E-Cigs May Be 'Bridge' to Teens' Tobacco Use

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_163491.html E-Cigs May Be 'Bridge' to Teens' Tobacco Use ' ... 8, 2017 (HealthDay News) -- Nonsmoking teens who use e-cigarettes appear to be more likely to light ...

  9. Sexual Risk Behavior: HIV, STD, & Teen Pregnancy Prevention

    Science.gov (United States)

    ... Glance Project Connect Sexual Health STD Teen Pregnancy Sexual Risk Behaviors: HIV, STD, & Teen Pregnancy Prevention Recommend ... Tweet Share Compartir Many young people engage in sexual risk behaviors that can result in unintended health ...

  10. Teens with ADHD Face a Higher Crash Risk

    Science.gov (United States)

    ... Health News on Attention Deficit Hyperactivity Disorder Motor Vehicle Safety Teen Health Recent Health News Related MedlinePlus Health Topics Attention Deficit Hyperactivity Disorder Motor Vehicle Safety Teen Health About MedlinePlus Site Map FAQs Customer ...

  11. Vital Signs-Preventing Pregnancy in Younger Teens

    Centers for Disease Control (CDC) Podcasts

    2014-04-08

    This podcast is based on the April 2014 CDC Vital Signs report. Births to teens are declining, still, in 2012, more than 86,000 teens ages 15 to 17 gave birth. This program discusses what health care providers, parents, and teens can do to help prevent teen pregnancy.  Created: 4/8/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 4/8/2014.

  12. Teens Take Stand on Bullying, but Resources Are Needed

    Science.gov (United States)

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    Nine percent of 13- to 15-year-old teens and 3% of teens 16 to 18 years old say they are "always" or "often" bullied to a point that makes them feel very sad, angry, sad, or upset. Over one-quarter of all teens say they are "sometimes" bullied to this point. This article presents some results of a "Harris Poll" of 776 teens surveyed online in…

  13. Jumping without using legs: the jump of the click-beetles (Elateridae is morphologically constrained.

    Directory of Open Access Journals (Sweden)

    Gal Ribak

    Full Text Available To return to their feet, inverted click-beetles (Elateridae jump without using their legs. When a beetle is resting on its dorsal side, a hinge mechanism is locked to store elastic energy in the body and releases it abruptly to launch the beetle into the air. While the functional morphology of the jumping mechanism is well known, the level of control that the beetle has over this jumping technique and the mechanical constraints governing the jumps are not entirely clear. Here we show that while body rotations in air are highly variable, the jumps are morphologically constrained to a constant "takeoff" angle (79.9°±1.56°, n = 9 beetles that directs 98% of the jumping force vertically against gravity. A physical-mathematical model of the jumping action, combined with measurements from live beetle, imply that the beetle may control the speed at takeoff but not the jumping angle. In addition, the model shows that very subtle changes in the exact point of contact with the ground can explain the vigorous rotations of the body seen while the beetle is airborne. These findings suggest that the evolution of this unique non-legged jumping mechanism resulted in a jumping technique that is capable of launching the body high into the air but it is too constrained and unstable to allow control of body orientation at landing.

  14. Realized Jump Risk and Equity Return in China

    Directory of Open Access Journals (Sweden)

    Guojin Chen

    2014-01-01

    Full Text Available We utilize the realized jump components to explore a new jump (including nonsystematic jump and systematic jump risk factor model. After estimating daily realized jumps from high-frequency transaction data of the Chinese A-share stocks, we calculate monthly jump size, monthly jump standard deviation, and monthly jump arrival rate and then use those monthly jump factors to explain the return of the following month. Our empirical results show that the jump tail risk can explain the equity return. For the large capital-size stocks, large cap stock portfolios, and index, one-month lagged jump risk factor significantly explains the asset return variation. Our results remain the same even when we add the size and value factors in the robustness tests.

  15. A Study of Taiwanese Teens' Traditional and Cyberbullying Behaviors

    Science.gov (United States)

    Yang, Shu Ching; Lin, Chia-Ying; Chen, An-Sing

    2014-01-01

    This study examined several types of teen behaviors, specifically bullying, being bullied, and witnessing bullying, and analyzed teens' judgments of the seriousness of the bullying. A Bullying Behaviors Scale (BBS) was designed to investigate both traditional bullying (TB) and cyberbullying (CB) behaviors among teens in grades 5 through 11. The…

  16. The Impact of Teen Court on Young Offenders. Research Report.

    Science.gov (United States)

    Butts, Jeffrey A.; Buck, Janeen; Coggeshall, Mark B.

    This paper reports findings from the Evaluation of Teen Courts Project, which studied teen courts in Alaska, Arizona, Maryland, and Missouri. Researchers measured pre-court attitudes and post-court (6-month) recidivism among more than 500 juveniles referred to teen court for nonviolent offenses. The study compared recidivism outcomes for teen…

  17. Teen Depression and Suicide: Effective Prevention and Intervention Strategies

    Science.gov (United States)

    King, Keith A.; Vidourek, Rebecca A.

    2012-01-01

    Teen depression and suicidal behaviors are intricately intertwined, with untreated depression being a leading cause of adolescent suicide. Most depressed or suicidal teens tend to show warning signs and possess specific risk factors. A key component to preventing teen depression is for adults to remain aware of such warning signs and risk factors…

  18. Youth Participation in VOYA Means Adults Sponsoring Teens.

    Science.gov (United States)

    MacRae, Cathi Dunn

    1998-01-01

    Discusses youth participation (YP) and adult mentorship in public libraries and Voice of Youth Advocates (VOYA), highlighting teen writing opportunities in VOYA: book reviews; annual poetry contest; an occasional column relating teen culture to books, information, entertainment, media, and identity; and occasional lists of favorite teen music,…

  19. Teen Depression and Suicide: Effective Prevention and Intervention Strategies

    Science.gov (United States)

    King, Keith A.; Vidourek, Rebecca A.

    2012-01-01

    Teen depression and suicidal behaviors are intricately intertwined, with untreated depression being a leading cause of adolescent suicide. Most depressed or suicidal teens tend to show warning signs and possess specific risk factors. A key component to preventing teen depression is for adults to remain aware of such warning signs and risk factors…

  20. Teen Pregnancy and Parenthood: Infants and Toddlers Who Need Care.

    Science.gov (United States)

    Thomson, Malia; Caulfield, Rick

    1998-01-01

    First of a two-part series, examines effects of teen pregnancy and parenthood on adolescents and their children, and describes exemplary program to keep teen parents in high school until graduation. Discusses how to address the issue of teenage pregnancy, how to effectively help teen parents, the importance of teaching teenagers personal…

  1. Teen Choice of Inwood House.

    Science.gov (United States)

    1994-05-01

    The Teen Choice Program in New York City was described and the outcome of the program evaluation was reported. Teen Choice is a school based sex education and pregnancy prevention program run by trained social workers. The aim is to provide information, counseling, and referrals on a range of issues relating to sexuality. The program is elective and meets during a regularly scheduled gym period for one or two semesters from the 7th to the 12th grades. There are single sex and coeducational classes. The program aim is to change attitudes toward birth control, to change risky sexual behavior, such as unprotected coitus, to offer accurate knowledge about contraception, and to prevent unplanned pregnancies. Abstinence is encouraged, but for those sexually experienced, there is attention to responsible and reliable use of contraception. Program methods include small group discussion, individual counseling, and classroom discussion. Topics of discussion range from sexuality issues and birth control to values clarification and peer pressure. Small groups may discuss human sexual growth, relationship formation, family life, responsibility to self and others, consequences of teenage pregnancy, and social and cultural peer pressures. Girls are encouraged to assume more assertive and less reactive roles. Communication skills are reinforced in respectful exchanges of personal views and questions. Differentiating facts and issues is a primary focus. A question about when an individual first had sex would be redirected to asking about the appropriate age to first have sex. Respect for privacy helps to build students confidence in the program. A longitudinal evaluation conducted between 1984 and 1987 found that the program was effective in reaching and recruiting high risk adolescents. Students left the program with increased knowledge about contraception, more mature and responsible attitudes about the use of birth control, and reduced frequency of unprotected coitus. Boys were

  2. Bubble visualization in a simulated hydraulic jump

    CERN Document Server

    Witt, Adam; Shen, Lian

    2013-01-01

    This is a fluid dynamics video of two- and three-dimensional computational fluid dynamics simulations carried out at St. Anthony Falls Laboratory. A transient hydraulic jump is simulated using OpenFOAM, an open source numerical solver. A Volume of Fluid numerical method is employed with a realizable k-epsilon turbulence model. The goal of this research is to model the void fraction and bubble size in a transient hydraulic jump. This fluid dynamics video depicts the air entrainment characteristics and bubble behavior within a hydraulic jump of Froude number 4.82.

  3. Social Determinants and Teen Pregnancy Prevention.

    Science.gov (United States)

    Fuller, Taleria R; White, Carla P; Chu, Jocelyn; Dean, Deborah; Clemmons, Naomi; Chaparro, Carmen; Thames, Jessica L; Henderson, Anitra Belle; King, Pebbles

    2016-12-01

    Addressing the social determinants of health (SDOH) that influence teen pregnancy is paramount to eliminating disparities and achieving health equity. Expanding prevention efforts from purely individual behavior change to improving the social, political, economic, and built environments in which people live, learn, work, and play may better equip vulnerable youth to adopt and sustain healthy decisions. In 2010, the Centers for Disease Control and Prevention in partnership with the Office of Adolescent Health funded state- and community-based organizations to develop and implement the Teen Pregnancy Prevention Community-Wide Initiative. This effort approached teen pregnancy from an SDOH perspective, by identifying contextual factors that influence teen pregnancy and other adverse sexual health outcomes among vulnerable youth. Strategies included, but were not limited to, conducting a root cause analysis and establishing nontraditional partnerships to address determinants identified by community members. This article describes the value of an SDOH approach for achieving health equity, explains the integration of such an approach into community-level teen pregnancy prevention activities, and highlights two project partners' efforts to establish and nurture nontraditional partnerships to address specific SDOH.

  4. Teen online problem solving for teens with traumatic brain injury: Rationale, methods, and preliminary feasibility of a teen only intervention.

    Science.gov (United States)

    Wade, Shari L; Narad, Megan E; Kingery, Kathleen M; Taylor, H Gerry; Stancin, Terry; Kirkwood, Michael W; Yeates, Keith O

    2017-08-01

    To describe the Teen Online Problem Solving-Teen Only (TOPS-TO) intervention relative to the original Teen Online Problem Solving-Family (TOPS-F) intervention, to describe a randomized controlled trial to assess intervention efficacy, and to report feasibility and acceptability of the TOPS-TO intervention. Research method and design: This is a multisite randomized controlled trial, including 152 teens (49 TOPS-F, 51 TOPS-TO, 52 IRC) between the ages of 11-18 who were hospitalized for a moderate to severe traumatic brain injury in the previous 18 months. Assessments were completed at baseline, 6-months post baseline, and 12-months post baseline. Data discussed include adherence and satisfaction data collected at the 6-month assessment (treatment completion) for TOPS-F and TOPS-TO. Adherence measures (sessions completed, dropout rates, duration of treatment engagement, and rates of program completion) were similar across treatment groups. Overall, teen and parent reported satisfaction was high and similar across groups. Teens spent a similar amount of time on the TOPS website across groups, and parents in the TOPS-F spent more time on the TOPS website than those in the TOPS-TO group (p = .002). Parents in the TOPS-F group rated the TOPS website as more helpful than those in the TOPS-TO group (p = .05). TOPS-TO intervention is a feasible and acceptable intervention approach. Parents may perceive greater benefit from the family based intervention. Further examination is required to understand the comparative efficacy in improving child and family outcomes, and who is likely to benefit from each approach. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Start your own information marketing business

    CERN Document Server

    Skrob, Robert

    2013-01-01

    Breaking down the information marketing world from A to Z, the undisputed info marketing expert offers professional strategies to set up a successful information marketing business. These businesses are easy to start, can be run from home, don't require any employees, need little cash outlay, can be run part-time, and can produce millions of dollars a year. Readers learn everything they need to jump into this lucrative field, creating an entirely new business that gives them added income or replaces their current salary entirely.

  6. Teens, Kindness and Cruelty on Social Network Sites: How American Teens Navigate the New World of "Digital Citizenship"

    Science.gov (United States)

    Lenhart, Amanda; Madden, Mary; Smith, Aaron; Purcell, Kristen; Zickuhr, Kathryn; Rainie, Lee

    2011-01-01

    Social media use has become so pervasive in the lives of American teens that having a presence on a social network site is almost synonymous with being online. Fully 95% of all teens ages 12-17 are now online and 80% of those online teens are users of social media sites. The authors focused their attention in this research on social network sites…

  7. Young Adult Outcomes of Children Born to Teen Mothers: Effects of Being Born during Their Teen or Later Years

    Science.gov (United States)

    Lipman, Ellen L.; Georgiades, Katholiki; Boyle, Michael H.

    2011-01-01

    Objective: Children of teen mothers exhibit adverse outcomes through adolescence. It is unclear whether these adverse outcomes extend to adulthood and apply to all of her children, or only those born when she was a teen. We examine the associations between young adult functioning and being born to a teen mother aged less than or equal to 20 years…

  8. A double-ended queue with catastrophes and repairs, and a jump-diffusion approximation

    CERN Document Server

    Di Crescenzo, Antonio; Kumar, Balasubramanian Krishna; Nobile, Amelia G; 10.1007/s11009-011-9214-2

    2011-01-01

    Consider a system performing a continuous-time random walk on the integers, subject to catastrophes occurring at constant rate, and followed by exponentially-distributed repair times. After any repair the system starts anew from state zero. We study both the transient and steady-state probability laws of the stochastic process that describes the state of the system. We then derive a heavy-traffic approximation to the model that yields a jump-diffusion process. The latter is equivalent to a Wiener process subject to randomly occurring jumps, whose probability law is obtained. The goodness of the approximation is finally discussed.

  9. Control Improvement for Jump-Diffusion Processes with Applications to Finance

    Energy Technology Data Exchange (ETDEWEB)

    Baeuerle, Nicole, E-mail: nicole.baeuerle@kit.edu [Karlsruhe Institute of Technology, Institute for Stochastics (Germany); Rieder, Ulrich, E-mail: ulrich.rieder@uni-ulm.de [University of Ulm, Department of Optimization and Operations Research (Germany)

    2012-02-15

    We consider stochastic control problems with jump-diffusion processes and formulate an algorithm which produces, starting from a given admissible control {pi}, a new control with a better value. If no improvement is possible, then {pi} is optimal. Such an algorithm is well-known for discrete-time Markov Decision Problems under the name Howard's policy improvement algorithm. The idea can be traced back to Bellman. Here we show with the help of martingale techniques that such an algorithm can also be formulated for stochastic control problems with jump-diffusion processes. As an application we derive some interesting results in financial portfolio optimization.

  10. Vocabulary Development of Junior Teens

    Directory of Open Access Journals (Sweden)

    L. V. Nikonova

    2013-01-01

    Full Text Available The article deals with the communicative competence formation of young adolescents in the secondary school at the Russian language lessons. The author maintains that the key element of the above problem is the vocabulary development guaranteeing both comprehension and verbal expression formation – oral and written. The theoretical part of the research explores different word functions: nominal, communicative, text generating and semantic. The correlation between the mental development level and lexical semantic system formation is emphasized. The age specific features of junior teens are listed: rising interest to various life spheres and activi- ties, capability of formulating opinions and judgments, self-awareness, formation of values. The relationship complexity stimulates vocabulary development of 10 to 12 year-old children; however, the process requires peda- gogical facilitation.The monitoring of speech development proves the necessity of commutative competence formation of the fifth- and sixth-year pupils. The paper presents the model of communicative competence development and its approbation results received for the junior adolescents. 

  11. Vocabulary Development of Junior Teens

    Directory of Open Access Journals (Sweden)

    L. V. Nikonova

    2015-03-01

    Full Text Available The article deals with the communicative competence formation of young adolescents in the secondary school at the Russian language lessons. The author maintains that the key element of the above problem is the vocabulary development guaranteeing both comprehension and verbal expression formation – oral and written. The theoretical part of the research explores different word functions: nominal, communicative, text generating and semantic. The correlation between the mental development level and lexical semantic system formation is emphasized. The age specific features of junior teens are listed: rising interest to various life spheres and activi- ties, capability of formulating opinions and judgments, self-awareness, formation of values. The relationship complexity stimulates vocabulary development of 10 to 12 year-old children; however, the process requires peda- gogical facilitation.The monitoring of speech development proves the necessity of commutative competence formation of the fifth- and sixth-year pupils. The paper presents the model of communicative competence development and its approbation results received for the junior adolescents. 

  12. Contraceptive considerations in overweight teens.

    Science.gov (United States)

    Kaneshiro, Bliss; Edelman, Alison

    2011-10-01

    The purpose of this review is to explore the efficacy and safety of contraceptives in overweight adolescents. There are few studies exploring hormonal contraceptive efficacy and safety in overweight and obese adults and almost none addressing these issues in adolescents. Luckily for teens, in terms of safety, many of the comorbidities associated with obesity are yet to transpire and their options for contraception remain relatively unrestricted. Studies of the combined oral contraceptive pill and patch in adults suggest that efficacy may be decreased in overweight adolescents. There is no evidence to suggest that the efficacy of the contraceptive implant or intrauterine device (IUD) is decreased in overweight adolescents. Indeed, these long-acting reversible methods will be the best choice for many adolescents because of their high efficacy. Although the literature is not definitive, there is probably a subset of adolescents who are susceptible to weight gain with use of depot medroxyprogesterone acetate. Although there is little research regarding contraceptive efficacy in overweight adolescents, IUDs and implants will be the best methods for many adolescents because of their high efficacy, reversibility, and safety. (C) 2011 Lippincott Williams & Wilkins, Inc.

  13. The Crown Bite Jumping Herbst.

    Science.gov (United States)

    Owen, Reuel

    2003-01-01

    The Crown Bite Jumping Herbst Appliance is evaluated and combined with Straight Wire Arch Fixed Orthodontics in treatment of Class II, Division I malocclusions. This article will evaluate a combined orthodontic approach of "straightening teeth" and an orthognathic approach of "moving jaws or making skeletal changes." Orthodontic treatment cannot be accomplished well without establishing a healthy temporomandibular joint. This is defined by Keller as a joint that is "noiseless, painless and has a normal range of motion without deviation and deflection." It is not prudent to separate orthodontic treatment as its own entity without being aware of the changes in the temporomandibular joint before, during and after treatment. In other words, "If you're doing orthodontics you're doing TMJ treatment." One should treat toward a healthy, beautiful face asking, "Will proposed treatment achieve this goal?" Treatment should be able to be carried out in an efficient manner, minimizing treatment time, be comfortable and affordable for the patient, and profitable for the dentist. The finished treatment should meet Andrews' Six Keys of Occlusion, or Loudon's Twelve Commandments. Above all, do no harm to the patient. We think that a specific treatment plan can embrace these tenets. The focus will be to show Class II treatment using a modified Herbst Appliance and fixed straight wire orthodontics.

  14. Parental involvement with their working teens.

    Science.gov (United States)

    Runyan, Carol W; Vladutiu, Catherine J; Schulman, Michael D; Rauscher, Kimberly J

    2011-07-01

    Adolescents work in varied environments and are exposed to hazards. Parents of these working adolescents have an opportunity to help them select jobs and address worker safety issues with employers. The present study conducted telephonic interviews among a national sample of 922 working adolescents along with one parent of each to examine the involvement of parents in their children's employment and safety issues. Over 70% of parents were found who helped their children identify job opportunities, consider questions about work hours or tasks, fill out job applications, prepare for interviews, or handle difficult safety issues. Parents suggested stronger actions in response to hypothetical situations than when confronted with real problems. Mean level of parental involvement did not vary by the number of hazards reported by teen workers. Parents were involved in helping their teens with work. Further research should explore how to enhance parental effectiveness by making work safe for teens.

  15. Volatility jumps and their economic determinants

    DEFF Research Database (Denmark)

    Caporin, Massimiliano; Rossi, Eduardo; Santucci de Magistris, Paolo

    that there is a positive probability of jumps in volatility. A common factor in the volatility jumps is shown to be related to a set of financial covariates (such as variance risk premium, S&P500 volume, credit-default swap, and federal fund rates). The credit-default swap on US banks and variance risk premium have...... predictive power on expected jump moves, thus confirming the common interpretation that sudden and large increases in equity volatility can be anticipated by credit deterioration of the US bank sector as well as changes in the market expectations of future risks. Finally, the model is extended to incorporate...... the credit-default swap and the variance risk premium in the dynamics of the jump size and intensity....

  16. ZATPAC: a model consortium evaluates teen programs.

    Science.gov (United States)

    Owen, Kathryn; Murphy, Dana; Parsons, Chris

    2009-09-01

    How do we advance the environmental literacy of young people, support the next generation of environmental stewards and increase the diversity of the leadership of zoos and aquariums? We believe it is through ongoing evaluation of zoo and aquarium teen programming and have founded a consortium to pursue those goals. The Zoo and Aquarium Teen Program Assessment Consortium (ZATPAC) is an initiative by six of the nation's leading zoos and aquariums to strengthen institutional evaluation capacity, model a collaborative approach toward assessing the impact of youth programs, and bring additional rigor to evaluation efforts within the field of informal science education. Since its beginning in 2004, ZATPAC has researched, developed, pilot-tested and implemented a pre-post program survey instrument designed to assess teens' knowledge of environmental issues, skills and abilities to take conservation actions, self-efficacy in environmental actions, and engagement in environmentally responsible behaviors. Findings from this survey indicate that teens who join zoo/aquarium programs are already actively engaged in many conservation behaviors. After participating in the programs, teens showed a statistically significant increase in their reported knowledge of conservation and environmental issues and their abilities to research, explain, and find resources to take action on conservation issues of personal concern. Teens also showed statistically significant increases pre-program to post-program for various conservation behaviors, including "I talk with my family and/or friends about things they can do to help the animals or the environment," "I save water...," "I save energy...," "When I am shopping I look for recycled products," and "I help with projects that restore wildlife habitat."

  17. Portfolio Selection with Jumps under Regime Switching

    Directory of Open Access Journals (Sweden)

    Lin Zhao

    2010-01-01

    Full Text Available We investigate a continuous-time version of the mean-variance portfolio selection model with jumps under regime switching. The portfolio selection is proposed and analyzed for a market consisting of one bank account and multiple stocks. The random regime switching is assumed to be independent of the underlying Brownian motion and jump processes. A Markov chain modulated diffusion formulation is employed to model the problem.

  18. Drive Alive: Teen Seat Belt Survey Program

    OpenAIRE

    Loftin, Laurel; Barlament, James; Cotton, Carol; Davidson, Steve M; Burkett, Katie M.; Stephens, James

    2010-01-01

    Objective: To increase teen seat belt use among drivers at a rural high school by implementing the Drive Alive Pilot Program (DAPP), a theory-driven intervention built on highway safety best practices.Methods: The first component of the program was 20 observational teen seat belt surveys conducted by volunteer students in a high school parking lot over a 38-month period before and after the month-long intervention. The survey results were published in the newspaper. The second component was t...

  19. Strategic Project/ CanTeen Ireland

    OpenAIRE

    Feehan, Yvonne

    2013-01-01

    CanTeen Ireland is an organisation set up to support, empower and develop young people who have or have had cancer between the ages of 12 and 25. Set up in May 1990, the nationwide support group provides members with a place where they can simply be young people, away from the day to day pressures that come with living with cancer in the hospital or at home. Having no dedicated wards in Irish hospitals for teenagers with cancer, CanTeen is an important resource for the country and steps up wh...

  20. Possible enhancement of SASE FEL output field intensity induced by local phase jump

    Science.gov (United States)

    Varfolomeev, A. A.; Yarovoi, T. V.; Bousine, P. V.

    1998-02-01

    A possible influence on the FEL dynamics of a locally induced phase jump between the FEL radiation and electron beam is considered. A numerical study has been made for the SASE mode FEL supposing that the phase jumps are introduced at different depths inside the undulator. The FEL evolution starting from a small input signal was studied in 1D high gain approach. It was shown that the FEL radiation output is sensitive to the phase jump value if it is introduced at the depth where saturation of output power takes places. In the steady state regime, the phase displacement of order ˜π provides enhancement of the peak output power up to 50%. Some kind of optical tapering is also possible giving further FEL efficiency enhancement.

  1. Performance analysis of jump-gliding locomotion for miniature robotics.

    Science.gov (United States)

    Vidyasagar, A; Zufferey, Jean-Christohphe; Floreano, Dario; Kovač, M

    2015-03-26

    Recent work suggests that jumping locomotion in combination with a gliding phase can be used as an effective mobility principle in robotics. Compared to pure jumping without a gliding phase, the potential benefits of hybrid jump-gliding locomotion includes the ability to extend the distance travelled and reduce the potentially damaging impact forces upon landing. This publication evaluates the performance of jump-gliding locomotion and provides models for the analysis of the relevant dynamics of flight. It also defines a jump-gliding envelope that encompasses the range that can be achieved with jump-gliding robots and that can be used to evaluate the performance and improvement potential of jump-gliding robots. We present first a planar dynamic model and then a simplified closed form model, which allow for quantification of the distance travelled and the impact energy on landing. In order to validate the prediction of these models, we validate the model with experiments using a novel jump-gliding robot, named the 'EPFL jump-glider'. It has a mass of 16.5 g and is able to perform jumps from elevated positions, perform steered gliding flight, land safely and traverse on the ground by repetitive jumping. The experiments indicate that the developed jump-gliding model fits very well with the measured flight data using the EPFL jump-glider, confirming the benefits of jump-gliding locomotion to mobile robotics. The jump-glide envelope considerations indicate that the EPFL jump-glider, when traversing from a 2 m height, reaches 74.3% of optimal jump-gliding distance compared to pure jumping without a gliding phase which only reaches 33.4% of the optimal jump-gliding distance. Methods of further improving flight performance based on the models and inspiration from biological systems are presented providing mechanical design pathways to future jump-gliding robot designs.

  2. Teen motherhood and long-term health consequences.

    Science.gov (United States)

    Patel, Payal H; Sen, Bisakha

    2012-07-01

    The objective of this article is to examine the association of teen motherhood and long-term physical and mental health outcomes. The physical and mental health components (PCS and MCS) of the SF-12 Healthy Survey in the NLSY79 health module were used to assess long-term health outcomes of women who experienced teenage motherhood. Various familial, demographic, and environmental characteristics were indentified and controlled for that may have predicted teen motherhood and long-term health outcomes. The two comparison groups for teen mothers were women who experienced teen-pregnancy only and women who were engaged in unprotected sexual activity as a teenage but did not experience pregnancy. Multivariate ordinary least squares regression was used for analysis. The average PCS and MCS for teen mothers was 49.91 and 50.89, respectively. Teen mothers exhibited poorer physical health later in life compared to all women as well as the comparison groups. When controlling for age, teen mothers had significantly lower PCS and MCS scores compared to all other women. Furthermore, when controlling for familial, demographic, and environmental characteristics, teen mothers exhibited significantly lower PCS and MCS scores. When comparing teen mothers to the two comparison groups, PCS was not statistically different although MCS was significantly lower in the teen-pregnancy group. Teen motherhood does lead to poorer physical health outcomes later in life. On the other hand, poorer mental health outcomes in later life may be attributed to the unmeasured factors leading to a teen pregnancy and not teen motherhood itself. Additional research needs to be conducted on the long-term consequences of teen motherhood.

  3. Is the effect of a countermovement on jump height due to active state development?

    Science.gov (United States)

    Bobbert, Maarten F; Casius, L J Richard

    2005-03-01

    To investigate whether the difference in jump height between countermovement jumps (CMJ) and squat jumps (SJ) could be explained by a difference in active state during propulsion. Simulations were performed with a model of the human musculoskeletal system comprising four body segments and six muscles. The model's only input was STIM, the stimulation of muscles, which could be switched "off" or "on." After switching "on," STIM increased to its maximum at a fixed rate of change (dSTIM/dt). For various values of dSTIM/dt, stimulation switch times were optimized to produce a maximum height CMJ. From this CMJ, the configuration at the lowest height of the center of gravity (CG) was selected and used as static starting configuration for simulation of SJ. Next, STIM-switch times were optimized to find the maximum height SJ. Simulated CMJ and SJ closely resembled jumps of human subjects. Maximum jump height of the model was greater in CMJ than in SJ, with the difference ranging from 0.4 cm at infinitely high dSTIM/dt to about 2.5 cm at the lowest dSTIM/dt investigated. The greater jump height in CMJ was due to a greater work output of the hip extensor muscles. These muscles could produce more force and work over the first 30% of their shortening range in CMJ, due to the fact that they had a higher active state in CMJ than in SJ. The greater jump height in CMJ than in SJ could be explained by the fact that in CMJ active state developed during the preparatory countermovement, whereas in SJ it inevitably developed during the propulsion phase, so that the muscles could produce more force and work during shortening in CMJ.

  4. Jumping to conclusions in schizophrenia

    Directory of Open Access Journals (Sweden)

    Evans SL

    2015-07-01

    Full Text Available Simon L Evans,1 Bruno B Averbeck,2 Nicholas Furl31School of Psychology, University of Sussex, Brighton, East Sussex, UK; 2Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; 3Department of Psychology, Royal Holloway, University of London, Egham, Surrey, UKAbstract: Schizophrenia is a mental disorder associated with a variety of symptoms, including hallucinations, delusions, social withdrawal, and cognitive dysfunction. Impairments on decision-making tasks are routinely reported: evidence points to a particular deficit in learning from and revising behavior following feedback. In addition, patients tend to make hasty decisions when probabilistic judgments are required. This is known as “jumping to conclusions” (JTC and has typically been demonstrated by presenting participants with colored beads drawn from one of two “urns” until they claim to be sure which urn the beads are being drawn from (the proportions of colors vary in each urn. Patients tend to make early decisions on this task, and there is evidence to suggest that a hasty decision-making style might be linked to delusion formation and thus be of clinical relevance. Various accounts have been proposed regarding what underlies this behavior. In this review, we briefly introduce the disorder and the decision-making deficits associated with it. We then explore the evidence for each account of JTC in the context of a wider decision-making deficit and then go on to summarize work exploring JTC in healthy controls using pharmacological manipulations and functional imaging. Finally, we assess whether JTC might have a role in therapy.Keywords: ketamine, decision making, delusions, fMRI, urn task

  5. Understanding multiple levels of norms about teen pregnancy and their relationships to teens' sexual behaviors.

    Science.gov (United States)

    Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

    2014-06-01

    Researchers seeking to understand teen sexual behaviors often turn to age norms, but they are difficult to measure quantitatively. Previous work has usually inferred norms from behavioral patterns or measured group-level norms at the individual level, ignoring multiple reference groups. Capitalizing on the multilevel design of the Add Health survey, we measure teen pregnancy norms perceived by teenagers, as well as average norms at the school and peer network levels. School norms predict boys' perceived norms, while peer network norms predict girls' perceived norms. Peer network and individually perceived norms against teen pregnancy independently and negatively predict teens' likelihood of sexual intercourse. Perceived norms against pregnancy predict increased likelihood of contraception among sexually experienced girls, but sexually experienced boys' contraceptive behavior is more complicated: When both the boy and his peers or school have stronger norms against teen pregnancy he is more likely to contracept, and in the absence of school or peer norms against pregnancy, boys who are embarrassed are less likely to contracept. We conclude that: (1) patterns of behavior cannot adequately operationalize teen pregnancy norms, (2) norms are not simply linked to behaviors through individual perceptions, and (3) norms at different levels can operate independently of each other, interactively, or in opposition. This evidence creates space for conceptualizations of agency, conflict, and change that can lead to progress in understanding age norms and sexual behaviors.

  6. Predictors of race-day jockey falls in jumps racing in Australia.

    Science.gov (United States)

    Hitchens, P; Blizzard, L; Jones, G; Day, L; Fell, J

    2011-05-01

    Thoroughbred jumps racing jockeys have a fall rate greater than their flat racing counterparts. Previous studies have focused on factors that contribute to falls by horses but, to date, there has not been a study of risk factors for falls to jockeys in jumps races. Data on race-day falls were extracted from stipendiary stewards reports lodged with Principal Racing Authorities following each race meeting. Denominator data were provided by Racing Information Services Australia on races conducted from August 2002 until July 2009. Univariable and multivariable analyses, estimating incidence rate ratios, were conducted using Poisson regression. In multivariable analysis in hurdle racing, important predictors of falls were higher club level, larger field size, greater prize money, provisionally licensed jockeys and older jockeys. There were significant interactions between jockey licence and prize money; jockey age and previous rides this meeting; race grade and race distance; horse age and field size; and club level and field size. In steeplechase racing, important predictors were type of jump with lowest fall rates in races over Mark III jumps compared to standard fences, provisionally licensed jockeys, jockeys having had previous rides at a meeting, and larger field size. There were significant interactions between the number of previous starts by the horse and field size; race distance and prize money; and race distance and previous rides this meeting. This study has identified factors for falls in jumps racing that could form the basis for targeted strategies to improve occupational health and safety standards. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. A biomechanical comparison of the vertical jump, power clean, and jump squat.

    Science.gov (United States)

    MacKenzie, Sasho James; Lavers, Robert J; Wallace, Brendan B

    2014-01-01

    The purpose of this study was to compare the kinetics, kinematics, and muscle activation patterns of the countermovement jump, the power clean, and the jump squat with the expectation of gaining a better understanding of the mechanism of transfer from the power clean to the vertical jump. Ground reaction forces, electromyography, and joint angle data were collected from 20 trained participants while they performed the three movements. Relative to the power clean, the kinematics of the jump squat were more similar to those of the countermovement jump. The order in which the ankle, knee, and hip began extending, as well as the subsequent pattern of extension, was different between the power clean and countermovement jump. The electromyography data demonstrated significant differences in the relative timing of peak activations in all muscles, the maximum activation of the rectus femoris and biceps femoris, and in the activation/deactivation patterns of the vastus medialis and rectus femoris. The greatest rate of force development during the upward phase of these exercises was generated during the power clean (17,254 [Formula: see text]), which was significantly greater than both the countermovement jump (3836 [Formula: see text]) and jump squat (3517 [Formula: see text]) conditions (P < .001, [Formula: see text]).

  8. Sex Parties: Female Teen Sexual Experimentation

    Science.gov (United States)

    Toscano, Sharyl Eve

    2006-01-01

    Adolescent participants in a study aimed at exploring the nature and characteristics of girls' dating relationships revealed the phenomenon of sex parties. These teens defined a "sex party" as an opportunity to engage in sexual contact outside of typical dating relationships. Sexual activity could involve actual intercourse, but usually involved…

  9. Why Is My Voice Changing? (For Teens)

    Science.gov (United States)

    ... enter puberty earlier or later than others. How Deep Will My Voice Get? How deep a guy's voice gets depends on his genes: ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...

  10. Immunization Schedules for Preteens and Teens

    Science.gov (United States)

    ... with your child’s doctor. Spanish Version (en español) Vacunas recomendadas para los niños desde los 7 hasta ... Immunizations for Preteens and Teens (7-18 years)) Vacunas recomendadas [2 pages] (Recommended Immunizations) You can display ...

  11. Meningococcal Immunizations for Preteens and Teens

    Centers for Disease Control (CDC) Podcasts

    2015-08-11

    This podcast provides information about vaccine recommendations to help prevent meningococcal disease in preteens and teens.  Created: 8/11/2015 by National Center for Immunization and Respiratory Diseases (NCIRD), Division of Bacterial Diseases (DBD), Meningitis and Vaccine Preventable Diseases Branch (MVPDB).   Date Released: 8/11/2015.

  12. Welfare Reform and Reducing Teen Pregnancy.

    Science.gov (United States)

    Sawhill, Isabel V.

    2000-01-01

    Most adolescent mothers are unmarried and on welfare. Congress enacted new welfare legislation that emphasizes reducing teen pregnancy and requiring work, but states are reluctant to meet this challenge. Discusses child poverty's new face, public policy and culture wars, welfare reform, and social norms. Concludes that reducing unwed parenthood…

  13. Is My Penis Normal? (For Teens)

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness Is My Penis Normal? KidsHealth > For Teens > Is My Penis Normal? A A A en español ¿Es normal ... any guy who's ever worried about whether his penis is a normal size. There's a fairly wide ...

  14. Influence of Hip Pop on American Teens

    Institute of Scientific and Technical Information of China (English)

    王昕苹

    2006-01-01

    Hip pop has become the mainstream music in American right now, not only because of its multi-musical style but also because of the lyrics has a historic background. Its popularity has great impact on American teens ,especially on the fashion and the lifestyle.

  15. Coarctation of the Aorta (For Teens)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Coarctation of the Aorta KidsHealth > For Teens > Coarctation of ... of Yourself en español Estrechamiento aórtico What Is Coarctation of the Aorta? The aorta (pronounced: ay-OR- ...

  16. Schools Must Act on Teen Pregnancy.

    Science.gov (United States)

    Buie, James

    1987-01-01

    Urges school administrators to act now to establish innovative programs dealing with teen pregnancy and parenting problems. Argues for school-based clinics or special schools offering comprehensive health services such as birth control information and devices, referral, and childcare. Cites successful approaches in Fresno, California, and several…

  17. TeensHealth: Q&A

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Q&A Got a question? What do the experts have to say? Look here for answers to many of the questions teens ask us. Girl Stuff Can Bras Affect Breast Growth? Can I Get Sick From Using a ...

  18. NCI launches smoking cessation support for teens

    Science.gov (United States)

    A new effort to help teens quit smoking will use one of today’s teen’s most constant companions—the mobile phone. Developed by smoking cessation experts, SmokefreeTXT is a free text message cessation service that provides 24/7 encouragement, advice, and

  19. Teen Appeal — Touching the Moving Point

    Science.gov (United States)

    Handford, Christina

    An article to discuss the difficulties of designing educational multimedia for the teen target audience (13 - 16 year olds). The report will assess techniques used in existing online artefacts and reveal major trends in the attempt to appeal to this notoriously hard to reach user group.

  20. Teen Dating Violence Prevention Program Assessment

    Science.gov (United States)

    Lucas, Quincy Arrianna Rose

    2013-01-01

    The American Psychological Association (APA) has identified the prevention of and intervention in relationship violence as a top priority (APA, n.d.). According to the Center for Disease Control and Prevention's 2012 Teen Dating Violence Fact Sheet, dating violence is a serious problem in the United States. In accordance with Foshee et al. (1998):…

  1. The effect of wind on jumping distance in ski jumping--fairness assessed.

    Science.gov (United States)

    Virmavirta, Mikko; Kivekäs, Juha

    2012-09-01

    The special wind compensation system recently adopted by Fédération Internationale de Ski (FIS; International Ski Federation) to consider the effects of changing wind conditions has caused some controversy. Here, the effect of wind on jumping distance in ski jumping was studied by means of computer simulation and compared with the wind compensation factors used by FIS during the World Cup season 2009/2010. The results showed clearly that the effect of increasing head/tail wind on jumping distance is not linear: +17.4 m/-29.1 m, respectively, for a wind speed of 3 m/s. The linear formula used in the trial period of the wind compensation system was found to be appropriate only for a limited range of jumping distances as the gradient of the landing slope slows down the rate of distance change in long jumps.

  2. Filtering and control of stochastic jump hybrid systems

    CERN Document Server

    Yao, Xiuming; Zheng, Wei Xing

    2016-01-01

    This book presents recent research work on stochastic jump hybrid systems. Specifically, the considered stochastic jump hybrid systems include Markovian jump Ito stochastic systems, Markovian jump linear-parameter-varying (LPV) systems, Markovian jump singular systems, Markovian jump two-dimensional (2-D) systems, and Markovian jump repeated scalar nonlinear systems. Some sufficient conditions are first established respectively for the stability and performances of those kinds of stochastic jump hybrid systems in terms of solution of linear matrix inequalities (LMIs). Based on the derived analysis conditions, the filtering and control problems are addressed. The book presents up-to-date research developments and novel methodologies on stochastic jump hybrid systems. The contents can be divided into two parts: the first part is focused on robust filter design problem, while the second part is put the emphasis on robust control problem. These methodologies provide a framework for stability and performance analy...

  3. A locust-inspired miniature jumping robot.

    Science.gov (United States)

    Zaitsev, Valentin; Gvirsman, Omer; Ben Hanan, Uri; Weiss, Avi; Ayali, Amir; Kosa, Gabor

    2015-11-25

    Unmanned ground vehicles are mostly wheeled, tracked, or legged. These locomotion mechanisms have a limited ability to traverse rough terrain and obstacles that are higher than the robot's center of mass. In order to improve the mobility of small robots it is necessary to expand the variety of their motion gaits. Jumping is one of nature's solutions to the challenge of mobility in difficult terrain. The desert locust is the model for the presented bio-inspired design of a jumping mechanism for a small mobile robot. The basic mechanism is similar to that of the semilunar process in the hind legs of the locust, and is based on the cocking of a torsional spring by wrapping a tendon-like wire around the shaft of a miniature motor. In this study we present the jumping mechanism design, and the manufacturing and performance analysis of two demonstrator prototypes. The most advanced jumping robot demonstrator is power autonomous, weighs 23 gr, and is capable of jumping to a height of 3.35 m, covering a distance of 1.37 m.

  4. Mechanical jumping power in young athletes.

    Science.gov (United States)

    Viitasalo, J T; Osterback, L; Alen, M; Rahkila, P; Havas, E

    1987-09-01

    Mechanical jumping power was determined for 286 young male athletes representing six sports events and ranging in calendar and skeletal ages from 8.8 to 17.1 and from 7.8 to 18.1 years, respectively. The subjects performed successive maximal vertical jumps on a contact mat for 30 s. The number of jumps and their cumulative flight time after 15 and 30 s were used for calculations of mechanical power. The jumping performances of the young athletes were found to be reproducible from the age of 10-12 years in respect to the angular displacement of the knee and duration of contact. Absolute mechanical power, as well as power related to body weight, increased with calendar and skeletal ages. Of the anthropometric characteristics, the circumference of the thigh and body weight showed the highest correlation with mechanical power; subjects with the greatest thigh circumference and body weight having the lowest mechanical power. The subjects were divided into 'power' (track and field, gymnastics) and 'endurance' (skiing, orienteering) groups. The former reached higher mechanical power values than the latter. Mechanical power for the second 15-s jumping period was on average 4.7% lower than for the first. The events did not differ from each other in respect of the decrease in power.

  5. Nonlinear regimes on polygonal hydraulic jumps

    Science.gov (United States)

    Rojas, Nicolas

    2016-11-01

    This work extends previous leading and higher order results on the polygonal hydraulic jump in the framework of inertial lubrication theory. The rotation of steady polygonal jumps is observed in the transition from one wavenumber to the next one, induced by a change in height of an external obstacle near the outer edge. In a previous publication, the study of stationary polygons is considered under the assumption that the reference frame rotates with the polygons when the number of corners change, in order to preserve their orientation. In this research work I provide a Hamiltonian approach and the stability analysis of the nonlinear oscillator that describe the polygonal structures at the jump interface, in addition to a perturbation method that enables to explain, for instance, the diversity of patterns found in experiments. GRASP, Institute of Physics, University of Liege, Belgium.

  6. Aerodynamic Jump for Long Rod Penetrators

    Directory of Open Access Journals (Sweden)

    Mark L. Bundy

    2000-04-01

    Full Text Available Aerodynamic jump for a non-spinning kinetic energy penetrator is neither a discontinuous change in the ,direction of motion at the origin of free night, nor is it the converse, i.e. a cumulativer~direc4on over a domain of infinite extent. Rather aerodynamic jump, for such a projectile, is a localised redirection of the centre of gravity motion, caused ~ the force of lift due to yaw over ther4latively short region from entry into free flight until the yaw reaches its first maximum. The primary objective of this paper is to provide answtfrs to the questions like what is aerodynamic jump, what liauses it, !lnd wh~t aspects df the flight trajectory does it refer to, or account for .

  7. Planarity of 3,4-jump Graphs

    Institute of Scientific and Technical Information of China (English)

    魏二玲; 刘颜佩

    2004-01-01

    For a graph G of size ε≥1 and its edge-induced subgraphs H1 and H2 of size γ(1 < γ < ε), H1 is said to be obtained from H2 by an edge jump if there exist four distinct vertices u, v, ω and x in G such that (u,v)∈E(H2), (ω,x)∈E(G) - E(H2) and H1=H2 - (u, v) + (ω, x). In this article, the γ-jump graphs(r≥3) are discussed. A graph H is said to be an γ-jump graph of G if its vertices correspond to the edge induced graph of size γ in G and two vertices are adjacent if and only if one of the two corresponding subgraphs can be obtained from the other by an edge jump. For k≥2, the k-th iterated γ-jump graph Jrk(G) is defined as Jγ(Jγk-1 (G)), where Jγ1 (G) = Jγ(G). An infinite sequence {Gi} of graphs is planar if every graph Gi is planar. It is shown that there does not exist a graph G for which the sequence {J3k(G)} is planar, where k is any positive integer. Meanwhile, lim gen(J3k(G)) =∞, where gen(G) denotes the genus of a graph G, if the sequence k→∞J3k(G) is defined for every positive integer k. As for the 4-jump graph of a graph G,{J4k(G)} is planar if and only if G = C5. For γ≥5, whether the fix graph of the sequence {Jγk(G))exists is determined.

  8. Implementation Evaluation of "Steering Teens Safe": Engaging Parents to Deliver a New Parent-Based Teen Driving Intervention to Their Teens

    Science.gov (United States)

    Ramirez, Marizen; Yang, Jingzhen; Young, Tracy; Roth, Lisa; Garinger, Anne; Snetselaar, Linda; Peek-Asa, Corinne

    2013-01-01

    Parents play a fundamental role in teaching their children safe driving skills to reduce risk of motor vehicle crashes, the leading cause of death for teens. "Steering Teens Safe" is a new parent-based intervention that equips parents with communication skills to talk about, demonstrate, and practice safe driving behaviors and skills…

  9. Implementation Evaluation of "Steering Teens Safe": Engaging Parents to Deliver a New Parent-Based Teen Driving Intervention to Their Teens

    Science.gov (United States)

    Ramirez, Marizen; Yang, Jingzhen; Young, Tracy; Roth, Lisa; Garinger, Anne; Snetselaar, Linda; Peek-Asa, Corinne

    2013-01-01

    Parents play a fundamental role in teaching their children safe driving skills to reduce risk of motor vehicle crashes, the leading cause of death for teens. "Steering Teens Safe" is a new parent-based intervention that equips parents with communication skills to talk about, demonstrate, and practice safe driving behaviors and skills…

  10. Xinjiang Dushanzi Project Started Construction Started Construction

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Xinjiang Dushanzi petroleum refining and chemical integrated project,is the largest one so far in China, with a capacity of ten-million-ton petroleum refinery and onemillion-ton ethylene complex, directly under PetroChina Company Limited (PetroChina), was started construction along with laying a foundation on August 22, 2005.

  11. Spectral Analysis of Diffusions with Jump Boundary

    CERN Document Server

    Kolb, Martin

    2011-01-01

    In this paper we consider one-dimensional diffusions with constant coefficients in a finite interval with jump boundary and a certain deterministic jump distribution. We use coupling methods in order to identify the spectral gap in the case of a large drift and prove that that there is a threshold drift above which the bottom of the spectrum no longer depends on the drift. As a Corollary to our result we are able to answer two questions concerning elliptic eigenvalue problems with non-local boundary conditions formulated previously by Iddo Ben-Ari and Ross Pinsky.

  12. Aerodynamic Jump for Long Rod Penetrators

    OpenAIRE

    Mark L. Bundy

    2000-01-01

    Aerodynamic jump for a non-spinning kinetic energy penetrator is neither a discontinuous change in the ,direction of motion at the origin of free night, nor is it the converse, i.e. a cumulativer~direc4on over a domain of infinite extent. Rather aerodynamic jump, for such a projectile, is a localised redirection of the centre of gravity motion, caused ~ the force of lift due to yaw over ther4latively short region from entry into free flight until the yaw reaches its first maximum. The primary...

  13. Are cellular phone blocking applications effective for novice teen drivers?

    Science.gov (United States)

    Creaser, Janet I; Edwards, Christopher J; Morris, Nichole L; Donath, Max

    2015-09-01

    Distracted driving is a significant concern for novice teen drivers. Although cellular phone bans are applied in many jurisdictions to restrict cellular phone use, teen drivers often report making calls and texts while driving. The Minnesota Teen Driver Study incorporated cellular phone blocking functions via a software application for 182 novice teen drivers in two treatment conditions. The first condition included 92 teens who ran a driver support application on a smartphone that also blocked phone usage. The second condition included 90 teens who ran the same application with phone blocking but which also reported back to parents about monitored risky behaviors (e.g., speeding). A third control group consisting of 92 novice teen drivers had the application and phone-based software installed on the phones to record cellular phone (but not block it) use while driving. The two treatment groups made significantly fewer calls and texts per mile driven compared to the control group. The control group data also demonstrated a higher propensity to text while driving rather than making calls. Software that blocks cellular phone use (except 911) while driving can be effective at mitigating calling and texting for novice teen drivers. However, subjective data indicates that some teens were motivated to find ways around the software, as well as to use another teen's phone while driving when they were unable to use theirs. Cellular phone bans for calling and texting are the first step to changing behaviors associated with texting and driving, particularly among novice teen drivers. Blocking software has the additional potential to reduce impulsive calling and texting while driving among novice teen drivers who might logically know the risks, but for whom it is difficult to ignore calling or texting while driving. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

  14. Religiosity and teen birth rate in the United States

    OpenAIRE

    Strayhorn Joseph M; Strayhorn Jillian C

    2009-01-01

    Abstract Background The children of teen mothers have been reported to have higher rates of several unfavorable mental health outcomes. Past research suggests several possible mechanisms for an association between religiosity and teen birth rate in communities. Methods The present study compiled publicly accessible data on birth rates, conservative religious beliefs, income, and abortion rates in the U.S., aggregated at the state level. Data on teen birth rates and abortion originated from th...

  15. The Prevessin Control Room during LEP's start up in 1989.

    CERN Multimedia

    1989-01-01

    The Prévessin Control Room saw its first momentous event when the 400 GeV beam for the SPS was commissioned in the presence of Project Leader John Adams. It was also here that the first proton-antiproton collisions were observed, in 1981. Eight years later, in 1989, operators and directors alike jumped for joy at the announcement of the first electron-positron collisions at the start up of LEP, the biggest accelerator in the world.

  16. Adult outcomes of teen mothers across birth cohorts

    Directory of Open Access Journals (Sweden)

    Anne Driscoll

    2014-04-01

    Full Text Available Background: Teen and young adult mothers have lower socioeconomic status than older mothers. Objective: This study analyzes the socioeconomic status (SES of teen, young adult, and older adult mothers across four five-year birth cohorts from 1956 to 1975 who were teens from 1971 to 1994. Methods: Data were pooled from the 1995, 2002, and 2006-2010 National Survey of Family Growth (NSFG. Mothers were categorized by age at first birth and by their birth cohorts. The SES (education, single motherhood, poverty, employment of teen, young adult, and older mothers was compared across cohorts and within cohorts. Results: Among teen mothers, the odds of fulltime employment improved across birth cohorts and the odds of educational attainment beyond high school did not vary. Their odds of single motherhood and living in poverty increased across cohorts. The odds of higher education and single motherhood increased across birth cohorts for young adult mothers as did the odds of living in poverty, even if working fulltime. Among older adult mothers, educational attainment and the odds of single motherhood rose for recent cohorts. Conclusions: Comparisons between teen mothers and both young adult and all adult mothers within cohorts suggest that gaps in single motherhood and poverty between teen and adult mothers have widened over time, to the detriment of teen mothers. Teen mothers have become more likely to be single and poor than in the past and compared to older mothers.

  17. Prenatal and postnatal cocaine exposure predict teen cocaine use.

    Science.gov (United States)

    Delaney-Black, Virginia; Chiodo, Lisa M; Hannigan, John H; Greenwald, Mark K; Janisse, James; Patterson, Grace; Huestis, Marilyn A; Partridge, Robert T; Ager, Joel; Sokol, Robert J

    2011-01-01

    Preclinical studies have identified alterations in cocaine and alcohol self-administration and behavioral responses to pharmacological challenges in adolescent offspring following prenatal exposure. To date, no published human studies have evaluated the relation between prenatal cocaine exposure and postnatal adolescent cocaine use. Human studies of prenatal cocaine-exposed children have also noted an increase in behaviors previously associated with substance use/abuse in teens and young adults, specifically childhood and teen externalizing behaviors, impulsivity, and attention problems. Despite these findings, human research has not addressed prior prenatal exposure as a potential predictor of teen drug use behavior. The purpose of this study was to evaluate the relations between prenatal cocaine exposure and teen cocaine use in a prospective longitudinal cohort (n=316) that permitted extensive control for child, parent and community risk factors. Logistic regression analyses and Structural Equation Modeling revealed that both prenatal exposure and postnatal parent/caregiver cocaine use were uniquely related to teen use of cocaine at age 14 years. Teen cocaine use was also directly predicted by teen community violence exposure and caregiver negativity, and was indirectly related to teen community drug exposure. These data provide further evidence of the importance of prenatal exposure, family and community factors in the intergenerational transmission of teen/young adult substance abuse/use. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Teen birth rates in sexually abused and neglected females.

    Science.gov (United States)

    Noll, Jennie G; Shenk, Chad E

    2013-04-01

    Prospectively track teen childbirths in maltreated and nonmaltreated females and test the hypothesis that child maltreatment is an independent predictor of subsequent teen childbirth over and above demographic characteristics and other risk factors. Nulliparous adolescent females (N = 435) aged 14 to 17 years were assessed annually through age 19 years. Maltreated females were referred by Child Protective Services agencies for having experienced substantiated sexual abuse, physical abuse, or neglect within the preceding 12 months. Comparison females were matched on race, family income, age and family constellation. Teen childbirth was assessed via self-report during annual interviews. Births were confirmed using hospital delivery records. Seventy participants gave birth during the study, 54 in the maltreated group and 16 in the comparison group. Maltreated females were twice as likely to experience teen childbirth after controlling for demographic confounds and known risk factors (odds ratio = 2.17, P = 0.01). Birth rates were highest for sexually abused and neglected females. Sexual abuse and neglect were both independent predictors of teen childbirth after controlling for demographic confounds, other risk factors and alternative forms of maltreatment occurring earlier in development. Results provide evidence that sexual abuse and neglect are unique predictors of subsequent teen childbirth. Partnerships between protective service providers and teen childbirth prevention strategists hold the best promise for further reducing the US teen birth rate. Additional research illuminating the pathways to teen childbirth for differing forms of maltreatment is needed so that tailored interventions can be realized.

  19. [Effects of TeenSTAR, an abstinence only sexual education program, on adolescent sexual behavior].

    Science.gov (United States)

    Vigil, Pilar; Riquelme, Rosa; Rivadeneira, Rosario; Aranda, Waldo

    2005-10-01

    Urgent measures are required to stop the increase in the frequency of pregnancies and sexually transmitted diseases among teenagers. A means of facing this problem is promoting sexual abstinence among youngsters. There are studies that confirm the efficacy of this approach. To show the results of the application of a holistic sexuality program (TeenSTAR) among Chilean teenagers. Students attending basic or high school were divided into a control or study group. The control group (342 students) received the usual education on sexuality given by their schools and the study group (398 students) participated in twelve TeenSTAR sessions lasting 1.5 hours each, given by a trained professor. Assessment of achievements was made using an anonymous questionnaire answered at the start and end of the program. The rates of sexual initiation among control and study groups were 15 and 6.5%, respectively. Among sexually active students, 20% of those in the study group and 9% of those in the control group discontinued sexual activity. A higher proportion of students in the TeenSTAR program retarded their sexual initiation or discontinued sexual activity and found more reasons to maintain sexual abstinence than control students.

  20. Recovery Outline: New Mexico Jumping Mouse (Zapus hudsonius luteus)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this recovery outline is to provide an interim strategy to guide the conservation and recovery of the New Mexico meadow jumping mouse (jumping mouse)...

  1. Steering teens safe: a randomized trial of a parent-based intervention to improve safe teen driving.

    Science.gov (United States)

    Peek-Asa, Corinne; Cavanaugh, Joseph E; Yang, Jingzhen; Chande, Vidya; Young, Tracy; Ramirez, Marizen

    2014-07-31

    Crashes are the leading cause of death for teens, and parent-based interventions are a promising approach. We assess the effectiveness of Steering Teens Safe, a parent-focused program to increase safe teen driving. Steering Teens Safe aimed to improve parental communication with teens about safe driving using motivational interviewing techniques in conjunction with 19 safe driving lessons. A randomized controlled trial involved 145 parent-teen dyads (70 intervention and 75 control). Intervention parents received a 45-minute session to learn the program with four follow-up phone sessions, a DVD, and a workbook. Control parents received a standard brochure about safe driving. Scores were developed to measure teen-reported quantity and quality of parental communication about safe driving. The main outcome measure was a previously validated Risky Driving Score reported by teens. Because the Score was highly skewed, a generalized linear model based on a gamma distribution was used for analysis. Intervention teens ranked their parent's success in talking about driving safety higher than control teens (p = 0.035) and reported that their parents talked about more topics (non-significant difference). The Risky Driving Score was 21% lower in intervention compared to control teens (85% CI = 0.60, 1.00). Interaction between communication quantity and the intervention was examined. Intervention teens who reported more successful communication had a 42% lower Risky Driving Score (95% CI = 0.37, 0.94) than control parents with less successful communication. This program had a positive although not strong effect, and it may hold the most promise in partnership with other programs, such as Driver's Education or Graduated Driver's License policies. ClinicalTrials.gov NCT01014923. Registered Nov. 16, 2009.

  2. Four weeks of optimal load ballistic resistance training at the end of season attenuates declining jump performance of women volleyball players.

    Science.gov (United States)

    Newton, Robert U; Rogers, Ryan A; Volek, Jeff S; Häkkinen, Keijo; Kraemer, William J

    2006-11-01

    Anecdotal and research evidence is that vertical jump performance declines over the competitive volleyball season. The purpose of this study was to evaluate whether a short period of ballistic resistance training would attenuate this loss. Fourteen collegiate women volleyball players were trained for 11 weeks with periodized traditional and ballistic resistance training. There was a 5.4% decrease (p ballistic training period (midseason to end of season), but values were not different from start to end of season. These changes in overall jump performance were reflective of changes in underlying neuromuscular performance variables: in particular, power output and peak velocity during loaded jump squats, countermovement jumps, and drop jumps. During the first 7 weeks of traditional heavy resistance training, it appears that the neuromuscular system is depressed, perhaps by the combination of training, game play, and skills practice precluding adequate recovery. Introduction of a novel training stimulus in the form of ballistic jump squats and reduction of heavy resistance training of the leg extensors stimulated a rebound in performance, in some cases to exceed the athlete's ability at the start of the season. Periodization of in-season training programs similar to that used in this study may provide volleyball players with good vertical jump performance for the crucial end-of-season games.

  3. Brief report: Teen sexting and psychosocial health.

    Science.gov (United States)

    Temple, Jeff R; Le, Vi Donna; van den Berg, Patricia; Ling, Yan; Paul, Jonathan A; Temple, Brian W

    2014-01-01

    The current study examines whether adolescents who report sexting exhibit more psychosocial health problems, compared to their non-sexting counterparts. Participants included 937 ethnically diverse male and female adolescents recruited and assessed from multiple high schools in southeast Texas. Measures included self-report of sexting, impulsivity, alcohol and drug use, and depression and anxiety symptoms. Teen sexting was significantly associated with symptoms of depression, impulsivity, and substance use. When adjusted for prior sexual behavior, age, gender, race/ethnicity, and parent education, sexting was only related to impulsivity and substance use. While teen sexting appears to correlate with impulsive and high-risk behaviors (substance use), we did not find sexting to be a marker of mental health.

  4. Start-Up Capital

    OpenAIRE

    Verheul, Ingrid; Thurik, Roy

    2000-01-01

    textabstractFemale and male entrepreneurs differ in the way they finance their businesses. This can be attributed to the type of business and the type of management and experience (indirect effect). Female start-ups may also experience other barriers based upon discriminatory effects (direct effect). Whether gender has an impact on size and composition of start-up capital, is the subject of the present paper. To test for these direct and indirect effects data of 2000 Dutch starting entreprene...

  5. Understanding the Physics of Bungee Jumping

    Science.gov (United States)

    Heck, Andre; Uylings, Peter; Kedzierska, Ewa

    2010-01-01

    Changing mass phenomena like the motion of a falling chain, the behaviour of a falling elastic bar or spring, and the motion of a bungee jumper surprise many a physicist. In this article we discuss the first phase of bungee jumping, when the bungee jumper falls, but the bungee rope is still slack. In instructional material this phase is often…

  6. Jumping Rope at Day of Play

    Science.gov (United States)

    2005-01-01

    Sarah Dastugue, 11, leaps in the air as Libby Knox, 9, swings a jump rope. The children were participants in Nickelodeon's Worldwide Day of Play celebration at Stennis Space Center (SSC) on Oct. 1. On the day of the event, children all over the world participate in physical activities as part of the celebration.

  7. Understanding the physics of bungee jumping

    NARCIS (Netherlands)

    Heck, A.; Uylings, P.; Kędzierska, E.

    2010-01-01

    Changing mass phenomena like the motion of a falling chain, the behaviour of a falling elastic bar or spring, and the motion of a bungee jumper surprise many a physicist. In this article we discuss the first phase of bungee jumping, when the bungee jumper falls, but the bungee rope is still slack.

  8. Jumping on the Social Media Bandwagon

    Science.gov (United States)

    Blakeslee, Lori

    2012-01-01

    Should a school district jump on the social media bandwagon? Yes! Social media provide a low-cost way to communicate school district priorities, influence decision makers, and tell its story without filters. Equally important, social media are where constituents are spending a lot of their time. With more than 800 million members, Facebook is an…

  9. Jumping on the Social Media Bandwagon

    Science.gov (United States)

    Blakeslee, Lori

    2012-01-01

    Should a school district jump on the social media bandwagon? Yes! Social media provide a low-cost way to communicate school district priorities, influence decision makers, and tell its story without filters. Equally important, social media are where constituents are spending a lot of their time. With more than 800 million members, Facebook is an…

  10. Jumping-droplet electrostatic energy harvesting

    Science.gov (United States)

    Miljkovic, Nenad; Preston, Daniel J.; Enright, Ryan; Wang, Evelyn N.

    2014-07-01

    Micro- and nanoscale wetting phenomena have been an active area of research due to its potential for improving engineered system performance involving phase change. With the recent advancements in micro/nanofabrication techniques, structured surfaces can now be designed to allow condensing coalesced droplets to spontaneously jump off the surface due to the conversion of excess surface energy into kinetic energy. In addition to being removed at micrometric length scales (˜10 μm), jumping water droplets also attain a positive electrostatic charge (˜10-100 fC) from the hydrophobic coating/condensate interaction. In this work, we take advantage of this droplet charging to demonstrate jumping-droplet electrostatic energy harvesting. The charged droplets jump between superhydrophobic copper oxide and hydrophilic copper surfaces to create an electrostatic potential and generate power during formation of atmospheric dew. We demonstrated power densities of ˜15 pW/cm2, which, in the near term, can be improved to ˜1 μW/cm2. This work demonstrates a surface engineered platform that promises to be low cost and scalable for atmospheric energy harvesting and electric power generation.

  11. DISCONTINUOUS FLOW OF TURBID DENSITY CURRENTS Ⅱ. INTERNAL HYDRAULIC JUMP

    Institute of Scientific and Technical Information of China (English)

    Jiahua FAN

    2005-01-01

    Traveling and stationary internal hydraulic jumps in density currents with positive or negative entrainment coefficients were analyzed based on simple assumptions. An expression of internal hydraulic jumps with entrainment coefficients was derived. Experimental data, published in literature, of stationary internal hydraulic jumps in turbid, thermal and saline density currents including measured values of water entrainment were used to compare with theory. Comparison was also made of traveling internal hydraulic jumps between measured data and theory.

  12. Brief Report: Teen Sexting and Psychosocial Health

    OpenAIRE

    Temple, Jeff R.; Le, Vi Donna; Van Den Berg, Patricia; Ling, Yan; Paul, Jonathan A.; Temple, Brian W.

    2013-01-01

    The current study examines whether adolescents who report sexting exhibit more psychosocial health problems, compared to their non-sexting counterparts. Participants included 937 ethnically diverse male and female adolescents recruited and assessed from multiple high schools in southeast Texas. Measures included self-report of sexting, impulsivity, alcohol and drug use, and depression and anxiety symptoms. Teen sexting was significantly associated with symptoms of depression, impulsivity, and...

  13. Getting Teens to Really Work in Class

    Science.gov (United States)

    Lauria de Gentile, Patricia; Leiguarda de Orue, Ana Maria

    2012-01-01

    Working with teenagers is not an easy task. This seems to be a notion shared by language teachers all over the world. While some instructors are very keen on working with this special age group, others are not fond of the challenge. The truth is that teaching English as a Second/Foreign Language (ESL/EFL) to teens has never been easy. According to…

  14. Option Valuation with Observable Volatility and Jump Dynamics

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Feunou, Bruno; Jeon, Yoontae

    Under very general conditions, the total quadratic variation of a jump-diffusion process can be decomposed into diffusive volatility and squared jump variation. We use this result to develop a new option valuation model in which the underlying asset price exhibits volatility and jump intensity dy...

  15. Determination of jumps for functions via derivative Gabor series

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ying-ying; SHI Xian-liang

    2009-01-01

    Recently, Shi Xianliang and Hu Lan published the method of concentration factors for determination of jumps of functions via MCM conjugate wavelets. Usually, it is difficult to calculate the Hilbert transform of general window functions. The aim of this paper is to discuss determination of jumps for functions based on derivative Gabor series. The results will simplify the calculation of jump values.

  16. Risk factors for epistaxis in jump racing in Great Britain (2001-2009).

    Science.gov (United States)

    Reardon, Richard J M; Boden, Lisa A; Mellor, Dominic J; Love, Sandy; Newton, Richard J; Stirk, Anthony J; Parkin, Timothy D

    2015-07-01

    The aim of this study was to evaluate risk factors associated with developing epistaxis in jump racing in Great Britain (GB). A retrospective analysis of records from horses running in all hurdle and steeplechase races in GB between 2001 and 2009 identified diagnoses of epistaxis whilst still at the racecourse. Data were used from 603 starts resulting in epistaxis (event) and 169,065 starts resulting in no epistaxis (non-event) in hurdle racing, and from 550 event starts and 102,344 non-event starts in steeplechase racing. Two multivariable logistic regression models to evaluate risk factors associated with epistaxis were produced. The potential effect of clustering of data (within horse, horse dam, horse sire, trainer, jockey, course, race and race meet) on the associations between risk factors and epistaxis was examined using mixed-effects models. Multiple factors associated with increased risk of epistaxis were identified. Those identified in both types of jump racing included running on firmer ground; horses with >75% of career starts in flat racing and a previous episode of epistaxis recorded during racing. Risk factors identified only in hurdle racing included racing in the spring and increased age at first race; and those identified only in steeplechase racing included running in a claiming race and more starts in the previous 3-6 months. The risk factors identified provide important information about the risk of developing epistaxis. Multiple avenues for further investigation are highlighted, including unmeasured variables at the level of the racecourse. The results of this study can be used to guide the development of interventions to minimise the risk of epistaxis in jump racing. Copyright © 2015. Published by Elsevier Ltd.

  17. Implementation evaluation of steering teens safe: engaging parents to deliver a new parent-based teen driving intervention to their teens.

    Science.gov (United States)

    Ramirez, Marizen; Yang, Jingzhen; Young, Tracy; Roth, Lisa; Garinger, Anne; Snetselaar, Linda; Peek-Asa, Corinne

    2013-08-01

    Parents play a fundamental role in teaching their children safe driving skills to reduce risk of motor vehicle crashes, the leading cause of death for teens. Steering Teens Safe is a new parent-based intervention that equips parents with communication skills to talk about, demonstrate, and practice safe driving behaviors and skills with their teens. This implementation evaluation focuses on a sample of 83 parents who delivered Steering Teens Safe to their teens. One-, 2- and 3-month follow-up assessments were conducted with intervention parents to evaluate the self-reported quantity and quality of talking about, demonstrating, and practicing safe driving goals with teens; perceived success and benefit of the program; and barriers to implementation. Over 3 months of follow-up, parents discussed driving goals with their teens for a median of 101.5 minutes. The most frequently addressed topics were general safety principles, including distracted driving, driving in bad weather, wearing a seat belt, and being a safe passenger. Parents spent a median of 30 minutes practicing safe driving skills such as changing lanes. Sixty-seven percent of parents talked to their children about rural road safety, but just 36% demonstrated and half practiced these skills with their teens. Barriers to implementation include time and opportunity barriers and resistant attitudes of their teens. However, barriers neither affected frequency of engagement nor parents' perceived benefit and comfort in delivering the program. Parents with time/opportunity barriers also had higher practice and demonstration times than parents without these barriers. Findings indicate high acceptability among parent implementers and promise for real-world delivery. Future studies are needed to assess intervention impact.

  18. Linear kinematics at take-off in horses jumping the wall in an international Puissance competition.

    Science.gov (United States)

    Powers, Pippa

    2005-07-01

    Sagittal plane SVHS video recordings (50 Hz) were made of horses jumping the wall at an international Puissance competition. Video sequences were manually digitized and six kinematic variables at take-off were analyzed. Nine horses started the competition with the fence height at 1.80 m, and two horses attempted the fence in the fifth and final round with the fence height at 2.27 m. For successful performances, fence height was correlated with the following take-off variables: vertical velocity of the centre of mass (r = 0.45, p = 0.03); height of centre of mass (r = 0.44, p = 0.04); distance of centre of mass from fence (r = 0.46, p = 0.03); and distance from leading hind limb to centre of mass (r = -0.61, p horses jumping over a Puissance wall. The results should help horse riders and trainers improve performance in Puissance jumping horses, and perhaps help in the early selection of horses with a talent for jumping high fences.

  19. Sliding mode control scheme for a jumping robot with multi-joint based on floating basis

    Science.gov (United States)

    Jianjun, Yao; Duotao, Di; Shuang, Gao; Lei, He; Shenghai, Hu

    2012-01-01

    A jumping robot has different jumping characteristics. The emphasis of its motion characteristics is placed on the sagittal plane, and every phase of a whole jumping motion has different constraints, so it is a variable constraint system. Its kinematic and dynamic equations, both of the stance phase and of the flight phase are established. Furthermore, the floating basis method is applied to unify the dynamic equations of the stance phase and the flight phase. The generalised coordinate is found based on the union of the tiptoe translation and the joint variables to obtain dynamic equations with constraints. Since the jumping robot is a strongly coupled system and has great impact when it lands on the ground, a reaching law is applied in the development of sliding mode controller in task space such that the state trajectory starting from anywhere can move towards the switching surface, making the system tracking error converge exponentially to zero. Simulation results demonstrate the efficiency and validity of the proposed control system.

  20. pH-jump induced α-helix folding of poly-L-glutamic acid

    Science.gov (United States)

    Donten, Mateusz L.; Hamm, Peter

    2013-08-01

    pH jumps are a truly biomimetic technique to initiate non-equilibrium dynamics of biomolecules. In this work, the pH jump induced α-helix folding of poly-L-glutamic acid is investigated upon proton release from o-nitrobenzaldehyde. The aim of this work is twofold: On the one hand, design criteria of pH jump experiments are discussed, on the other hand, the folding mechanism of poly-L-glutamic acid is clarified by probing the IR response of the amide I band. Its folding kinetics is studied in dependence of the starting pD, the size of the pD jump and the length of the helix. While no dependence on the first two parameters could be detected, the folding time varies from 0.6 μs to 1.8 μs for helix lengths of 20 residue to 440 residue, respectively. It converges to a long-length limit at about 50 residue, a result which is attributed to a nucleation-propagation mechanism.

  1. The ripples of adolescent motherhood: social, educational, and medical outcomes for children of teen and prior teen mothers.

    Science.gov (United States)

    Jutte, Douglas P; Roos, Noralou P; Brownell, Marni D; Briggs, Gemma; MacWilliam, Leonard; Roos, Leslie L

    2010-01-01

    We examined medical, educational and social risks to children of teen mothers and children of nonadolescent mothers with a history of teen birth (prior teen mothers) and considered these risks at both the individual and societal level. A population-based, retrospective cohort study tracked outcomes through young adulthood for children born in Manitoba, Canada (n = 32 179). chi(2) and logistic regression analyses examined risk of childhood death or hospitalization, failure to graduate high school, intervention by child protective services, becoming a teen mother, and welfare receipt as a young adult. For children of both teen and prior teen mothers, adjusted likelihoods of death during infancy, school-aged years, and adolescence were more than 2-fold higher than for other children. Risks for hospitalization, high hospital use, academic failure, and poor social outcomes were also substantially higher. At a societal level, only 16.5% of cohort children were born to teen and prior teen mothers. However, these children accounted for 27% of first-year hospitalizations, 34% of deaths (birth to 17 years), 30% of failures to graduate high school, 51% in foster care, 44% on welfare as young adults, and 56% of next-generation young teen mothers. Children of prior teen mothers had increased risks for poor health and for educational and social outcomes nearly equal to those seen in children of teen mothers. Combined, these relatively few children experienced a large share of the negative outcomes occurring among young people. Our results suggest the need to expand the definition of risk associated with adolescent motherhood and target their children for enhanced medical and social services. Copyright 2010 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  2. Teens Reflect on Their Sources of Contraceptive Information

    Science.gov (United States)

    Jones, Rachel K.; Biddlecom, Ann E.; Hebert, Luciana; Mellor, Ruth

    2011-01-01

    Based on semistructured interviews with a racially and ethnically diverse sample of 58 U.S. high school students, this study examines teens' exposure to contraceptive information from a range of sources and the extent to which they trust this information. Teens report exposure to contraceptive information from many individuals and places, most…

  3. Examining External and Internal Poverty as Antecedents of Teen Pregnancy

    Science.gov (United States)

    Young, Tamera; Turner, Jean; Denny, George; Young, Michael

    2004-01-01

    Objectives: To identify antecedents of teen pregnancy. Methods: Data from the National Education Longitudinal Study were analyzed. This data set allowed us to identify eighth-grade antecedents of teen pregnancy/childbearing. Results: The variables that were found to be most predictive of later pregnancy were reflective of internal poverty (locus…

  4. Teen Pregnancy and the Achievement Gap among Urban Minority Youth

    Science.gov (United States)

    Basch, Charles E.

    2011-01-01

    Objectives: To outline the prevalence and disparities of teen pregnancy among school-aged urban minority youth, causal pathways through which nonmarital teen births adversely affects academic achievement, and proven or promising approaches for schools to address this problem. Methods: Literature review. Results: In 2006, the birth rate among 15-…

  5. Teens' Knowledge of Risk Factors for Sports Injuries

    Science.gov (United States)

    Ward, Cynthia W.

    2004-01-01

    Youth participation in sports has increased greatly over the past 20 years. Consequently, there has been a rise in the number of sports injuries. A study was conducted to determine teen's level of physical activity, knowledge about risk factors for sports injuries, use of protective equipment, and parental involvement. Two groups of teens, one of…

  6. Serving Teen Parents in a Welfare Reform Environment.

    Science.gov (United States)

    Stebbins, Helene

    The Personal Responsibility and Work Opportunity Reconciliation Act of 1996 presents states with new opportunities and flexibility to design programs for teen parents. This report summarizes how welfare reform has changed the environment for teen parents dependent on welfare. The report presents research findings on the costs of supporting teen…

  7. Talking to Kids and Teens About Social Media and Sexting

    Science.gov (United States)

    ... Facebook Twitter Talking to Kids and Teens About Social Media and Sexting Article Body Social Media Today’s teens and tweens are connected to one ... may have a problem with Internet or social media addiction. Contact your ... messages, and images periodically. Be transparent and let your kids know ...

  8. Designing Public Library Websites for Teens: A Conceptual Model

    Science.gov (United States)

    Naughton, Robin Amanda

    2012-01-01

    The main goal of this research study was to develop a conceptual model for the design of public library websites for teens (TLWs) that would enable designers and librarians to create library websites that better suit teens' information needs and practices. It bridges a gap in the research literature between user interface design in human-computer…

  9. Familiar Fairy Tale Picture Books Transformed into Teen Novels.

    Science.gov (United States)

    Chance, Rosemary

    2003-01-01

    Describes characteristics of fairy tales. Discusses use of fairy tales and novels for teens in the classroom. Presents annotations of 31 titles including both picture books and young adult novels grouped by nine popular tales. Concludes that through comparing picture books and teen novels, there is one last chance to introduce fairy tales to older…

  10. Weight-Loss Surgery Pays Off for Severely Obese Teens

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161700.html Weight-Loss Surgery Pays Off for Severely Obese Teens Boosts ... 26, 2016 WEDNESDAY, Oct. 26, 2016 (HealthDay News) -- Weight-loss surgeries can help severely obese teens shed pounds. ...

  11. Vital Signs – Preventing Repeat Teen Births

    Centers for Disease Control (CDC) Podcasts

    2013-04-02

    This podcast is based on the April 2013 CDC Vital Signs report, which discusses repeat teen births and ways teens, parents and guardians, health care providers, and communities can help prevent them.  Created: 4/2/2013 by Centers for Disease Control and Prevention (CDC).   Date Released: 4/2/2013.

  12. Why Teen Mental Ability Surges While Brain Shrinks

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_166310.html Why Teen Mental Ability Surges While Brain Shrinks Researchers say they may have answer to ... behavior keep scaling up," he said. So while teens lose brain volume and girls have lower brain volume than ...

  13. Teens Reflect on Their Sources of Contraceptive Information

    Science.gov (United States)

    Jones, Rachel K.; Biddlecom, Ann E.; Hebert, Luciana; Mellor, Ruth

    2011-01-01

    Based on semistructured interviews with a racially and ethnically diverse sample of 58 U.S. high school students, this study examines teens' exposure to contraceptive information from a range of sources and the extent to which they trust this information. Teens report exposure to contraceptive information from many individuals and places, most…

  14. Teen Girls and Technology: What's the Problem, What's the Solution?

    Science.gov (United States)

    Farmer, Lesley

    2008-01-01

    Are teenage girls being left behind in the technology race? According to author and professor Lesley Farmer, teenage girls are not embracing technology and all of its potential impact on their futures. In "Teen Girls and Technology", Farmer explores the developmental issues of teen girls, including the reality of girls and tech as it now stands.…

  15. Teen Culture, Technology and Literacy Instruction: Urban Adolescent Students' Perspectives

    Science.gov (United States)

    Li, Jia; Snow, Catherine; White, Claire

    2015-01-01

    Modern teens have pervasively integrated new technologies into their lives, and technology has become an important component of teen popular culture. Educators have pointed out the promise of exploiting technology to enhance students' language and literacy skills and general academic success. However, there is no consensus on the effect of…

  16. Mental Illness May Make Teens Vulnerable to Drugs, Alcohol

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160284.html Mental Illness May Make Teens Vulnerable to Drugs, Alcohol Brazilian study found half of those who smoked, drank, did pot had symptoms of psychological ... -- Teens who are struggling with mental health disorders are more likely to smoke cigarettes, ...

  17. Do Mothers' Opinions Matter in Teens' Sexual Activity?

    Science.gov (United States)

    Fingerson, Laura

    2005-01-01

    Using the Add Health data (N = 9,530 dyads), this study explores sexual socialization in the family using the theory of reasoned action by assessing how mothers' opinions are associated with their childrens' sexual behavior. Findings suggest that the more sexually liberal teens think their mothers are, the more likely the teens are to have higher…

  18. Teen Parents: The Crisis and the Challenge for Vocational Education.

    Science.gov (United States)

    Pittman, Karen

    1986-01-01

    Various issues concerning adolescent parenthood are discussed including economically disadvantaged teens, poor wages of high school dropouts, single parenthood, lack of reasons to delay parenthood, lack of job skills, and lack of child care facilities that would allow teen parents the opportunity to learn job skills. (CT)

  19. Resonant Messages to Prevent Prescription Drug Misuse by Teens

    Science.gov (United States)

    Twombly, Eric C.; Holtz, Kristen D.; Agnew, Christine B.

    2011-01-01

    Prescription drug misuse is a major health problem, particularly among teens. A key step in curbing misuse is the development of effective prescription drug prevention messages. This paper explores the elements of prescription drug misuse prevention messages that resonate with teens using data from focus groups with seventh and eighth grade…

  20. National Campaign to Prevent Teen and Unplanned Pregnancy

    Science.gov (United States)

    ... TheNC@20 Close Making the Case Teen Pregnancy Unplanned Pregnancy Public Cost National & State Data U.S. teen pregnancy ... the IUD a first line of defense against unplanned pregnancy. It won't be easy. TIME Magazine The ...

  1. Most Teens Say "It's Okay to Even the Score!"

    Science.gov (United States)

    Curriculum Review, 2009

    2009-01-01

    While today's teens are learning the Three "Rs" of Reading, Writing and Arithmetic in school, new research shows that many teens are justifying violence to practice a fourth--Revenge. In a youth culture where violence is often believed to be acceptable, experts say that these and other findings not only present disturbing implications for school…

  2. Urban Teens in the Library: Research and Practice

    Science.gov (United States)

    Agosto, Denise E., Ed.; Hughes-Hassell, Sandra, Ed.

    2009-01-01

    "Urban Teens in the Library" is the perfect solution for the concerns and uncertainty many librarians face when supporting this group of patrons and students. From a team of experts who have researched the information habits and preferences of urban teens to build better and more effective school and public library programs, this book will show…

  3. Confessions of Former Teen Program Participants: Two Decades Later

    Science.gov (United States)

    Flores, Fabrizio; Wyrick, Gabrielle; Zwicky, Calder

    2014-01-01

    As a companion to more data-driven articles and studies that consider the long-term impact of art museum teen programs on alumni, this article takes the form of a person to person interview with two founding teen members of important programs that emerged in the 1990s. Talking candidly about the impact of their program participation, Calder Zwicky…

  4. From Kickoff to Handoff: Coaching Teens to Tackle STEM Literacy

    Science.gov (United States)

    Ripberger, Chad; Blalock, Lydia B.

    2015-01-01

    This article discusses how intensive, content-rich, multiple-day conferences for teams of youth and their adult coaches can be used to initiate the training and planning needed for teens to successfully serve as STEM teachers. The concepts are based on three 4-H "teens as teachers" projects that included 29-36.5 hour initial training…

  5. Confessions of Former Teen Program Participants: Two Decades Later

    Science.gov (United States)

    Flores, Fabrizio; Wyrick, Gabrielle; Zwicky, Calder

    2014-01-01

    As a companion to more data-driven articles and studies that consider the long-term impact of art museum teen programs on alumni, this article takes the form of a person to person interview with two founding teen members of important programs that emerged in the 1990s. Talking candidly about the impact of their program participation, Calder Zwicky…

  6. Paediatrician knowledge, attitudes, and counselling patterns on teen driving.

    Science.gov (United States)

    Weiss, Jeffrey C; O'Neil, Joseph; Shope, Jean T; O'Connor, Karen G; Levin, Rebecca A

    2012-02-01

    Motor vehicle crashes (MVCs) are the leading cause of death among teenagers. Little is known about the content of US paediatrician counselling about teen driving. To examine US paediatrician knowledge, attitudes, and counselling patterns regarding teen driving. A random sample questionnaire was mailed to American Academy of Pediatrics members in 2009 (n=1606; response=875 (55%)). Analysis was limited to 596 paediatricians who provide adolescent checkups. Questions addressed counselling and attitudes towards roles in promoting safe driving. Logistic regression assessed the relationship between counselling topics and practice characteristics. Most (89%) respondents provide some counselling about driving. Two topics commonly discussed by paediatricians were seatbelts (87%) and alcohol use (82%). Less frequently discussed were: cell phones (47%), speeding (43%), and dangers of transporting teen passengers (41%). Topics rarely discussed were: night driving (21%), graduated driver licensing laws (13%), safe cars (9%), driver education (9%), fatigue (25%), and parental limit setting (23%). Only 10% ever recommend a parent-teen driver agreement. Paediatricians who had a patient injured or killed in an MVC were more likely to discuss night driving (OR=2.86). Physicians caring for a high proportion of adolescents (OR=1.83) or patients with private insurance (OR=1.85) counsel more about the risks of driving with teen passengers. Paediatricians in the USA support counselling on teen driving during routine office visits, but omit many important risk factors. Few recommend parent-teen driver agreements. Methods that help clinicians efficiently and effectively counsel families about teen driving should be developed.

  7. Designing Public Library Websites for Teens: A Conceptual Model

    Science.gov (United States)

    Naughton, Robin Amanda

    2012-01-01

    The main goal of this research study was to develop a conceptual model for the design of public library websites for teens (TLWs) that would enable designers and librarians to create library websites that better suit teens' information needs and practices. It bridges a gap in the research literature between user interface design in…

  8. A Survey of Teen Museum Education Participants and Their Parents

    Science.gov (United States)

    Hornby, Jenny; Bobick, Bryna

    2016-01-01

    In this article, we discuss a museum program for teens located in an urban environment. The participants were high school students from public, private, religious and home schools. The program allowed learning to occur in an informal setting and united teens from one city through a common interest in visual art. Also, it was an opportunity for the…

  9. Lift-off dynamics in a simple jumping robot

    CERN Document Server

    Aguilar, Jeffrey; Wiesenfeld, Kurt; Goldman, Daniel I

    2012-01-01

    We study vertical jumping in a simple robot comprising an actuated mass-spring arrangement. The actuator frequency and phase are systematically varied to find optimal performance. Optimal jumps occur above and below (but not at) the robot's resonant frequency $f_0$. Two distinct jumping modes emerge: a simple jump which is optimal above $f_0$ is achievable with a squat maneuver, and a peculiar stutter jump which is optimal below $f_0$ is generated with a counter-movement. A simple dynamical model reveals how optimal lift-off results from non-resonant transient dynamics.

  10. Dynamics of Coalescence-Induced Jumping Water Droplets

    CERN Document Server

    Miljkovic, Nenad; Enright, Ryan; Wang, Evelyn N

    2013-01-01

    This fluid dynamics video shows the different interaction mechanisms of coalescence-induced droplet jumping during condensation on a nanostructured superhydrophobic surface. High speed imaging was used to show jumping behavior on superhydrophobic copper oxide and carbon nanotube surfaces. Videos demonstrating multi-jumping droplets, jumping droplet return to the surface, and droplet-droplet electrostatic repulsions were analyzed. Experiments using external electric fields in conjunction with high speed imaging in a custom built experimental chamber were used to show that all coalescence-induced jumping droplets on superhydrophobic surfaces become positively charged upon leaving the surface, which is detailed in the video.

  11. Real Estate Funds. Fiscal incentives to jump-start the property market

    OpenAIRE

    Sabrina Capilupi

    2014-01-01

    Real estate funds are a financial instrument enabling investors to transform real estate Investments into shares of financial assets, producing liquidity without the investor having to acquire and dispose of property. A strong boost to this type of investment - an alternative to the type of securities - is given by the favourable tax laws that foster the creation, management and participation in real estate funds. This article summarises the main provisions related to tax applicable to ...

  12. Real Estate Funds. Fiscal incentives to jump-start the property market

    Directory of Open Access Journals (Sweden)

    Sabrina Capilupi

    2014-06-01

    Full Text Available Real estate funds are a financial instrument enabling investors to transform real estate Investments into shares of financial assets, producing liquidity without the investor having to acquire and dispose of property. A strong boost to this type of investment - an alternative to the type of securities - is given by the favourable tax laws that foster the creation, management and participation in real estate funds. This article summarises the main provisions related to tax applicable to funds in this sector.

  13. Using Service-Learning Projects to Jump Start Research at Small Institutions

    Science.gov (United States)

    Ongley, L. K.; Spigel, K.; Olin, J.

    2010-12-01

    Geoscientists at small institutions must frequently be very creative about funding and conducting research. High teaching loads, tuition-driven budgets, and a dearth of geosciences colleagues all contribute challenges to an intellectual life that includes research as a scholarship endeavor. Fortunately, service-learning can be used as a multi-purpose pedagogical technique. Unity College is a very small environmentally-focused undergraduate institution in rural Maine with a student population of less than 600 students. Our students really appreciate learning in the field and through participation in projects that impact the communities in which they live and study. Our Environmental Science (geosciences) and Environmental Analysis (chemistry) majors have been showing increasing interest in pursuing graduate school and independent projects in greater and greater depth. In the past 5 years we have had a complete turn-over in geoscience and chemistry faculty (2 persons), a shift that has brought new ideas to campus and a different idea about importance of research. Unity College has always been a big proponent of community-based projects so the extension to service learning as a pedagogical technique has been smooth. A wide variety of towns, schools, land trusts, pond associations and other groups approach Unity College with project ideas. We are best equipped to handle suggestions that relate to environmental chemistry and to lake sedimentation owing to the research interests of our geoscience faculty. We present two examples of ways to sequence student work that ultimately end in student/faculty research projects. Sophomores in the Unity College Environmental Stewardship Core curriculum may choose to take a course that introduces lake sedimentation as a tool to study environmental change. Students in the course take several sediment cores to analyze proxies of environmental change to reconstruct past environments. The final results are reported to the community client. Other sediment cores are preserved for upper-level students to use as detailed independent studies or senior thesis projects. In time, there will be enough data from enough lakes in the area to build a detailed picture of environmental change in this region of Maine and to predict expected impacts of climate change. The community clients for project of this type include Friends of Lake Winnecook and the Sebasticook Regional Land Trust. Over the past four years Environmental Analysis students have been working on arsenic in drinking water systems. Students have performed literature reviews, evaluated field techniques for analysis of arsenic in water and looked for diurnal variation in arsenic concentrations in a domestic water well. Next spring, one general chemistry lab section will set up and run “Arsenic Days”, a community event to which residents may bring a water sample for analysis of arsenic and other water quality parameters. This will provide a large dataset to assess the overall water quality in the three aquifers present in Unity, Maine. Some of this work is applicable to global water quality problems. The “clients” for this work include Chemists Without Borders and the Unity Barnraisers. In each case, the results of the research have been reported at various professional meetings as well as to the “client”.

  14. IT Career JumpStart An Introduction to PC Hardware, Software, and Networking

    CERN Document Server

    Alpern, Naomi J; Muller, Randy

    2011-01-01

    A practical approach for anyone looking to enter the IT workforce Before candidates can begin to prepare for any kind of certification, they need a basic understanding of the various hardware and software components used in a computer network. Aimed at aspiring IT professionals, this invaluable book strips down a network to its bare basics, and discusses this complex topic in a clear and concise manner so that IT beginners can confidently gain an understanding of fundamental IT concepts. In addition, a base knowledge has been established so that more advanced topics and technologies can be lea

  15. Jump-Starting Early Childhood Education at Home: Early Learning, Parent Motivation, and Public Policy.

    Science.gov (United States)

    Maloney, Erin A; Converse, Benjamin A; Gibbs, Chloe R; Levine, Susan C; Beilock, Sian L

    2015-11-01

    By the time children begin formal schooling, their experiences at home have already contributed to large variations in their math and language development, and once school begins, academic achievement continues to depend strongly on influences outside of school. It is thus essential that educational reform strategies involve primary caregivers. Specifically, programs and policies should promote and support aspects of caregiver-child interaction that have been empirically demonstrated to boost early learning and should seek to impede "motivational sinkholes" that threaten to undermine caregivers' desires to engage their children effectively. This article draws on cognitive and behavioral science to detail simple, low-cost, and effective tools caregivers can employ to prepare their children for educational success and then describes conditions that can protect and facilitate caregivers' motivation to use those tools. Policy recommendations throughout focus on using existing infrastructure to more deeply engage caregivers in effective early childhood education at home.

  16. From Dissertation Defense to Dissemination: Jump Start Your Academic Career With a Scholar Mentor Group.

    Science.gov (United States)

    Lehna, Carlee; Hermanns, Melinda; Monsivais, Diane B; Engebretson, Joan

    2016-01-01

    The dissertation provides an excellent source of scholarly productivity for new doctoral faculty, yet is often neglected because of the demands inherent in the faculty role. The purpose of this paper is to present a case study of a scholar mentor group composed of three graduates of a PhD nursing program and their shared dissertation chair, who acted as a senior scholar mentor to the group. By working together, we have been able to enhance our scholarly productivity by disseminating our dissertations through presentations and publications. The paper will present the evolving process of this working group, summarize outcomes, analyze the challenges, and provide suggestions for future doctoral students and faculty who are working with them. Our experience and scholar mentor model captures the best of both worlds-the benefits of interaction with academic peers and the benefits of having a senior scholar mentor. This was accomplished while all members were at different schools in different cities and states. Although other literatures that document successful collaborations using a peer-mentorship model are available, we were unable to locate any that documents a post-doctoral group with a senior scholar mentor who continued working together after graduation. © 2015 Wiley Periodicals, Inc.

  17. C# 4, ASP.NET 4, and WPF, with Visual Studio 2010 jump start

    CERN Document Server

    Nagel, Christian; Stephens, Rod; Hanselman, Scott; Glynn, Jay; Rader, Devin; Watson, Karli; Skinner, Morgan

    2010-01-01

    This Wrox Blox is a value-packed resource to help experienced .NETdevelopers learn the new .NET release. It is excerpted from theWrox books: Professional C# 4 and .NET 4, Professional ASP.NET4, and WPF Programmer's Reference by Christian Nagel,Bill Evjen, Scott Hanselman, and Rod Stephens, and includes morethan 100 print book pages drawn from these three key titles. It isan excellent resource to help .NET developers get up to speed faston .NET 4, C# 4.0, ASP.NET 4, and WPF, providing all theinformation needed to program with the important new features,including: C# Dynamic Types and Par

  18. Using Institutional Survey Data to Jump-Start Your Benchmarking Process

    Science.gov (United States)

    Chow, Timothy K. C.

    2012-01-01

    Guided by the missions and visions, higher education institutions utilize benchmarking processes to identify better and more efficient ways to carry out their operations. Aside from the initial planning and organization steps involved in benchmarking, a matching or selection step is crucial for identifying other institutions that have good…

  19. Jump Start: International High School Students From Other Countries Earning Early U.S. College Credits

    Science.gov (United States)

    Hu, Jiayi; Hagedorn, Linda Serra

    2015-01-01

    This study analyzes data from one of the larger credit-based college transition programs for international students, the U.S. Bound College Credit Program or USBC2 Program (a pseudonym), mainly offered to high school students around the globe who are planning on attending American colleges or universities. Upon successful program completion, these…

  20. Not Just Another Single Issue: Teen Pregnancy Prevention's Link to Other Critical Social Issues.

    Science.gov (United States)

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    This report discusses critical social issues linked to teen pregnancy, explaining that teen pregnancy prevention should be viewed as working to improve these social issues. After providing general background on teen pregnancy, the report offers five fact sheets: (1) "Teen Pregnancy, Welfare Dependency, and Poverty" (continuing to reduce…

  1. Baby Think It Over: Using Role-Play To Prevent Teen Pregnancy.

    Science.gov (United States)

    Out, Jennifer W.; Lafreniere, Kathryn D.

    2001-01-01

    Examined the effectiveness of Baby Think It Over (BTIO), an infant simulation program that seeks to modify attitudes toward teen pregnancy and teen parenting. After experiencing BTIO, teens in the intervention group were more likely to accurately access their personal risk for an unplanned pregnancy than were teens in the comparison group. (Author)

  2. Halfway There: A Prescription for Continued Progress in Preventing Teen Pregnancy.

    Science.gov (United States)

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    This report offers findings and recommendations by the National Campaign To Prevent Teen Pregnancy. Nearly one million teens become pregnant annually. The teen birth rate increased 24 percent between 1986-91 and has fallen 20 percent since then. Overall, too many parents and adult leaders do not take a strong stand against teen pregnancy. Strident…

  3. Teen Cyberbullying Investigated: Where Do Your Rights End and Consequences Begin?

    Science.gov (United States)

    Jacobs, Thomas A.

    2010-01-01

    The Internet age has led to a different kind of teen bullying: cyberbullying. What is cyberbullying and what can teens do about it? In "Teen Cyberbullying Investigated," Judge Tom Jacobs presents a powerful collection of landmark court cases involving teens and charges of cyberbullying and cyberharassment. This riveting, informative guide will…

  4. Teen Perceptions of the Promotion of Safer Sexual Practices: A Focus Group Study

    Science.gov (United States)

    Herrman, Judith W.; Kelley, Andrea; Haigh, Katherine M.

    2017-01-01

    Teens' own thoughts on fostering safe sexual practice are important perspectives in promoting adolescent sexual health yet are relatively absent in the literature. This focus group study explored teens' perceptions about the supports and challenges that exist as teens strive to engage in healthy sexual practices. Seventy-five teens participated in…

  5. Andragogy for Teen and Young Adult Learners with Intellectual Disabilities: Learning, Independence, and Best Practices

    Science.gov (United States)

    Bowman, Stephanie L.; Plourde, Lee A.

    2012-01-01

    Teens and young adults with Intellectual Disabilities (ID) meet the criteria of teen and adult learners chronologically, but may be deficient in many other areas of teen and adult learning. The spectrum of intellectual and adaptive capabilities among teens and adults with ID is vast, with each individual being unique. There are specific teaching…

  6. Teen Perceptions of the Promotion of Safer Sexual Practices: A Focus Group Study

    Science.gov (United States)

    Herrman, Judith W.; Kelley, Andrea; Haigh, Katherine M.

    2017-01-01

    Teens' own thoughts on fostering safe sexual practice are important perspectives in promoting adolescent sexual health yet are relatively absent in the literature. This focus group study explored teens' perceptions about the supports and challenges that exist as teens strive to engage in healthy sexual practices. Seventy-five teens participated in…

  7. Biomechanical Analysis of the Jump Shot in Basketball

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2014-10-01

    Full Text Available Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can utilise during a game when performing a jump shot. The study was conducted among 20 second-league basketball players by means of a Kistler force plate and the BTS SMART system for motion analysis. The variables measured included the take-off time, mean power, peak power, relative mean power, jump height, maximum landing force and calculated impact ratio. Surprisingly, more advantageous variables were found for the jump shot. This finding suggests a very high performance level in the jump shot in the studied group and a maximum utilisation of their motor abilities. Both types of jumps were characterised by high mean and peak power values and average heights. The high forces at landing, which result in considerable impact ratios, may have prompted the studied group to land softly. Use of the countermovement jump without an arm swing is recommended to assess and predict the progression of player’s jumping ability

  8. A teen's guide to creating web pages and blogs

    CERN Document Server

    Selfridge, Peter; Osburn, Jennifer

    2008-01-01

    Whether using a social networking site like MySpace or Facebook or building a Web page from scratch, millions of teens are actively creating a vibrant part of the Internet. This is the definitive teen''s guide to publishing exciting web pages and blogs on the Web. This easy-to-follow guide shows teenagers how to: Create great MySpace and Facebook pages Build their own unique, personalized Web site Share the latest news with exciting blogging ideas Protect themselves online with cyber-safety tips Written by a teenager for other teens, this book leads readers step-by-step through the basics of web and blog design. In this book, teens learn to go beyond clicking through web sites to learning winning strategies for web design and great ideas for writing blogs that attract attention and readership.

  9. Vital signs: teen pregnancy--United States, 1991--2009.

    Science.gov (United States)

    2011-04-08

    In 2009, approximately 410,000 teens aged 15-19 years gave birth in the United States, and the teen birth rate remains higher than in other developed countries. To describe U.S. trends in teen births and related factors, CDC used data on 1) teen birth rates during 1991-2009 from the National Vital Statistics System, 2) sexual intercourse and contraceptive use among high school students during 1991-2009 from the national Youth Risk Behavior Survey, and 3) sex education, parent communication, use of long-acting reversible contraceptives (LARCs), and receipt of reproductive health services among teens aged 15-19 years from the 2006-2008 National Survey of Family Growth. In 2009, the national teen birth rate was 39.1 births per 1,000 females, a 37% decrease from 61.8 births per 1,000 females in 1991 and the lowest rate ever recorded. State-specific teen birth rates varied from 16.4 to 64.2 births per 1,000 females and were highest among southern states. Birth rates for black and Hispanic teens were 59.0 and 70.1 births per 1,000 females, respectively, compared with 25.6 for white teens. From 1991 to 2009, the percentage of high school students who ever had sexual intercourse decreased from 54% to 46%, and the percentage of students who had sexual intercourse in the past 3 months but did not use any method of contraception at last sexual intercourse decreased from 16% to 12%. From 1999 to 2009, the percentage of students who had sexual intercourse in the past 3 months and used dual methods at last sexual intercourse (condoms with either birth control pills or the injectable contraceptive Depo-Provera) increased from 5% to 9%. During 2006-2008, 65% of female teens and 53% of male teens received formal sex education that covered saying no to sex and provided information on methods of birth control. Overall, 44% of female teens and 27% of male teens had spoken with their parents about both topics, but among teens who had ever had sexual intercourse, 20% of females and 31

  10. Scaled Jump in Gravity-Reduced Virtual Environments.

    Science.gov (United States)

    Kim, MyoungGon; Cho, Sunglk; Tran, Tanh Quang; Kim, Seong-Pil; Kwon, Ohung; Han, JungHyun

    2017-04-01

    The reduced gravity experienced in lunar or Martian surfaces can be simulated on the earth using a cable-driven system, where the cable lifts a person to reduce his or her weight. This paper presents a novel cable-driven system designed for the purpose. It is integrated with a head-mounted display and a motion capture system. Focusing on jump motion within the system, this paper proposes to scale the jump and reports the experiments made for quantifying the extent to which a jump can be scaled without the discrepancy between physical and virtual jumps being noticed by the user. With the tolerable range of scaling computed from these experiments, an application named retargeted jump is developed, where a user can jump up onto virtual objects while physically jumping in the real-world flat floor. The core techniques presented in this paper can be extended to develop extreme-sport simulators such as parasailing and skydiving.

  11. What Teens Want to Know: Sexual Health Questions Submitted to a Teen Web Site

    Science.gov (United States)

    Vickberg, Suzanne M. Johnson; Kohn, Julia E.; Franco, Lydia M.; Criniti, Shannon

    2003-01-01

    In 1999 Planned Parenthood[R] Federation of America (PPFA[R]) launched teenwire.com[SM], a Web site for young people. This study was designed to determine teens' reproductive health information needs. Selected for analysis were 1,219 submissions to the Ask the Experts section of the Web site. Each submission was independently coded by three of the…

  12. The teen impact experience: a webcast pilot project for teens with cancer and blood diseases.

    Science.gov (United States)

    Gonzalez-Morkos, Betty; Zavala, Octavio; Malogolowkin, Marcio; Kuperberg, Aura

    2014-01-01

    This article discusses a novel service, webcasting of a live group, implemented in response to the 2009-2010 H1N1 Flu pandemic by Teen Impact, a program geared at providing social therapy to adolescents diagnosed with cancer or a blood disorder. To ensure that services were not disrupted to adolescents on treatment despite flu restrictions, Teen Impact obtained necessary equipment to webcast the group. A total of 6 Teen Impact members participated in the webcast portion of the group. Findings revealed that existing members who had participated in the face-to-face Teen group were left with feelings of dissatisfaction due to lack of physical interaction with other members. New members appeared to enjoy this option admitting that the webcast provided them with the ability to feel supported by others with similar stories without having to face unknown members in person. A positive outcome from this type of intervention resulted in the webcast serving as a stepping stone for future face-to-face participation. © 2014 by Association of Pediatric Hematology/Oncology Nurses.

  13. Using Film Clips to Teach Teen Pregnancy Prevention: "The Gloucester 18" at a Teen Summit

    Science.gov (United States)

    Herrman, Judith W.; Moore, Christopher C.; Anthony, Becky

    2012-01-01

    Teaching pregnancy prevention to large groups offers many challenges. This article describes the use of film clips, with guided discussion, to teach pregnancy prevention. In order to analyze the costs associated with teen pregnancy, a film clip discussion session based with the film "The Gloucester 18" was the keynote of a youth summit. The lesson…

  14. The Relationship Between the Lower-Body Muscular Profile and Swimming Start Performance

    Directory of Open Access Journals (Sweden)

    García-Ramos Amador

    2016-04-01

    Full Text Available This study aimed to examine the correlation of different dry land strength and power tests with swimming start performance. Twenty international level female swimmers (age 15.3 ± 1.6 years, FINA point score 709.6 ± 71.1 performed the track freestyle start. Additionally, dry land tests were conducted: a squat (SJ and countermovement jumps (CMJ, b squat jumps with additional resistance equivalent to 25, 50, 75 and 100% of swimmers’ body weight [BW], and c leg extension and leg flexion maximal voluntary isometric contractions. Correlations between dry land tests and start times at 5, 10 and 15 m were quantified through Pearson’s linear correlation coefficients (r. The peak bar velocity reached during the jumps with additional resistance was the variable most correlated to swimming start performance (r = -0.57 to -0.66 at 25%BW; r = -0.57 to -0.72 at 50%BW; r = -0.59 to -0.68 at 75%BW; r = -0.50 to - 0.64 at 100%BW. A few significant correlations between the parameters of the SJ and the CMJ with times of 5 and 10 m were found, and none with the isometric variables. The peak velocity reached during jumps with external loads relative to BW was found a good indicator of swimming start performance.

  15. With One Voice 2002: America's Adults and Teens Sound Off about Teen Pregnancy. An Annual National Survey.

    Science.gov (United States)

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    Two national surveys, one of youth ages 12 to 19 and the other of adults over age 19 years, examined attitudes toward teen pregnancy. Respondents express more cautious attitudes toward early and casual sex than is generally believed, and large majorities of both groups support a strong abstinence message for teens coupled with information about…

  16. The Rate of Cyber Dating Abuse among Teens and How It Relates to Other Forms of Teen Dating Violence

    Science.gov (United States)

    Zweig, Janine M.; Dank, Meredith; Yahner, Jennifer; Lachman, Pamela

    2013-01-01

    To date, little research has documented how teens might misuse technology to harass, control, and abuse their dating partners. This study examined the extent of cyber dating abuse--abuse via technology and new media--in youth relationships and how it relates to other forms of teen dating violence. A total of 5,647 youth from ten schools in three…

  17. Teen Tobacco Court: A Determination of the Short-Term Outcomes of Judicial Processes with Teens Engaging in Tobacco Possession.

    Science.gov (United States)

    Langer, Lilly M.; Warheit, George J.

    2000-01-01

    Investigated the impact of a tobacco citation and subsequent court appearance on teens who possessed tobacco, examining offenders' attitudes and behaviors following citation and court appearance. Surveys and interviews indicated that being ticketed and appearing in teen tobacco court had significant, positive, short-term impacts on large numbers…

  18. The Rate of Cyber Dating Abuse among Teens and How It Relates to Other Forms of Teen Dating Violence

    Science.gov (United States)

    Zweig, Janine M.; Dank, Meredith; Yahner, Jennifer; Lachman, Pamela

    2013-01-01

    To date, little research has documented how teens might misuse technology to harass, control, and abuse their dating partners. This study examined the extent of cyber dating abuse--abuse via technology and new media--in youth relationships and how it relates to other forms of teen dating violence. A total of 5,647 youth from ten schools in three…

  19. Effects of a Teen Pregnancy Prevention Program on Teens' Attitudes toward Sexuality: A Latent Trait Modeling Approach

    Science.gov (United States)

    Thomas, Charles L.; Dimitrov, Dimiter M.

    2007-01-01

    The purpose of this study was to examine the effects of program interventions in a school-based teen pregnancy program on hypothesized constructs underlying teens' attitudes toward sexuality. An important task related to this purpose was the validation of the constructs and their stability from pre- to postintervention measures. Data from 1,136…

  20. FEMA DFIRM Station Start

    Data.gov (United States)

    Minnesota Department of Natural Resources — This table contains information about station starting locations. These locations indicate the reference point that was used as the origin for distance measurements...

  1. Early Head Start Evaluation

    Data.gov (United States)

    U.S. Department of Health & Human Services — Longitudinal information from an evaluation where children were randomly assigned to Early Head Start or community services as usual;direct assessments and...

  2. Head Start Impact Study

    Data.gov (United States)

    U.S. Department of Health & Human Services — Nationally representative, longitudinal information from an evaluation where children were randomly assigned to Head Start or community services as usual;direct...

  3. Capture of Trojans by Jumping Jupiter

    CERN Document Server

    Nesvorny, David; Morbidelli, Alessandro

    2013-01-01

    Jupiter Trojans are thought to be survivors of a much larger population of planetesimals that existed in the planetary region when planets formed. They can provide important constraints on the mass and properties of the planetesimal disk, and its dispersal during planet migration. Here we tested a possibility that the Trojans were captured during the early dynamical instability among the outer planets (aka the Nice model), when the semimajor axis of Jupiter was changing as a result of scattering encounters with an ice giant. The capture occurs in this model when Jupiter's orbit and its Lagrange points become radially displaced in a scattering event and fall into a region populated by planetesimals (that previously evolved from their natal transplanetary disk to ~5 AU during the instability). Our numerical simulations of the new capture model, hereafter jump capture, satisfactorily reproduce the orbital distribution of the Trojans and their total mass. The jump capture is potentially capable of explaining the ...

  4. Getting started with Unity

    CERN Document Server

    Felicia, Patrick

    2013-01-01

    Getting Started with Unity is written in an easy-to-follow tutorial format.""Getting Started with Unity"" is for[ 3D game developers[/color] who would like to learn how to use Unity3D and become familiar with its core features. This book is also suitable for intermediate users who would like to improve their skills. No prior knowledge of Unity3D is required.

  5. Later School Start Times: What Informs Parent Support or Opposition?

    Science.gov (United States)

    Dunietz, Galit Levi; Matos-Moreno, Amilcar; Singer, Dianne C; Davis, Matthew M; O'Brien, Louise M; Chervin, Ronald D

    2017-07-15

    To investigate parental knowledge about adolescent sleep needs, and other beliefs that may inform their support for or objection to later school start times. In 2014, we conducted a cross-sectional, Internet-based survey of a nationally representative sample of parents as part of the C.S. Mott Children's Hospital National Poll on Children's Health. Parents with teens aged 13-17 years reported their children's sleep patterns and school schedules, and whether the parents supported later school start times (8:30 am or later). Responses associated with parental support of later school start times were examined with logistic regression analysis. Overall, 88% of parents reported school start times before 8:30 am, and served as the analysis sample (n = 554). In this group, 51% expressed support for later school start times. Support was associated with current school start times before 7:30 am (odds ratio [OR] = 3.1 [95% confidence interval (CI) 1.2, 8.4]); parental opinion that their teen's current school start time was "too early" (OR = 3.8 [1.8, 7.8]); and agreement with American Academy of Pediatrics recommendations about school start times (OR = 4.7 [2.2, 10.1]). Support also was associated with anticipation of improved school performance (OR = 3.0 [1.5, 5.9]) or increased sleep duration (OR = 4.0 [1.8, 8.9]) with later school start times. Conversely, parents who anticipated too little time for after-school activities (OR = 0.5 [0.3, 0.9]) and need for different transportation plans (OR = 0.5 [0.2, 0.9]) were often less supportive. Parental education about healthy sleep needs and anticipated health benefits may increase their support for later school start times. Educational efforts should also publicize the positive experiences of communities that have made this transition, with regard to limited adverse effect on after-school activity schedules and transportation.

  6. Psychiatric Advance Directives: Getting Started

    Science.gov (United States)

    ... More... Home Getting Started National Resource Center on Psychiatric Advance Directives - Getting Started Getting Started Psychiatric advance directives (PADs) are relatively new legal instruments ...

  7. Quantum jumps of a fluxonium qubit

    Science.gov (United States)

    Vool, U.; Pop, I. M.; Sliwa, K.; Abdo, B.; Brecht, T.; Shankar, S.; Hatridge, M.; Schoelkopf, R. J.; Mirrahimi, M.; Glazman, L.; Devoret, M. H.

    2014-03-01

    The fluxonium qubit has recently been shown to have energy relaxation time (T1) of the order of 1 ms, limited by quasiparticle dissipation. With the addition of a Josephson Parametric Converter (JPC) to the experiment, trajectories corresponding to quantum jumps between the ground and 1st excited state can be measured, thus allowing the observation of the qubit decay in real time instead of that of an ensemble average. Our measurement fidelity with the JPC is in excess of 98% for an acquisition time of 5 us and we can thus continuously monitor the quantum jumps of the qubit in equilibrium with its environment in a time much shorter than its average relaxation time. We observe in our sample a jump statistics that varies from being completely Poissonian with a long (500 us) mean time in the ground state to being highly non-Poissonian with short (100 us) mean time in the ground state. The changes between these regimes occur on time scales of seconds, minutes and even hours. We have studied this effect and its relation to quasiparticle dynamics by injecting quasiparticles with a short intense microwave pulse and by seeding quasiparticle-trapping vortices with magnetic field. Work supported by: IARPA, ARO, and NSF.

  8. POTENTIAL FOR NON-CONTACT ACL INJURY BETWEEN STEP-CLOSE-JUMP AND HOP-JUMP TASKS

    Directory of Open Access Journals (Sweden)

    Li-I Wang

    2010-03-01

    Full Text Available This study aimed to compare the kinematics and kinetics during the landing of hop-jump and step-close-jump movements in order to provide further inferring that the potential risk of ACL injuries. Eleven elite male volleyball players were recruited to perform hop-jump and step-close-jump tasks. Lower extremity kinematics and ground reaction forces during landing in stop-jump tasks were recorded. Lower extremity kinetics was calculated by using an inverse dynamic process. Step-close-jump tasks demonstrated smaller peak proximal tibia anterior shear forces during the landing phase. In step-close-jump tasks, increasing hip joint angular velocity during initial foot-ground contact decreased peak posterior ground reaction force during the landing phase, which theoretically could reduce the risk of ACL injury

  9. An Efficient Interpolation Technique for Jump Proposals in Reversible-Jump Markov Chain Monte Carlo Calculations

    CERN Document Server

    Farr, Will M

    2011-01-01

    Selection among alternative theoretical models given an observed data set is an important challenge in many areas of physics and astronomy. Reversible-jump Markov chain Monte Carlo (RJMCMC) is an extremely powerful technique for performing Bayesian model selection, but it suffers from a fundamental difficulty: it requires jumps between model parameter spaces, but cannot retain a memory of the favored locations in more than one parameter space at a time. Thus, a naive jump between parameter spaces is unlikely to be accepted in the MCMC algorithm and convergence is correspondingly slow. Here we demonstrate an interpolation technique that uses samples from single-model MCMCs to propose inter-model jumps from an approximation to the single-model posterior of the target parameter space. The interpolation technique, based on a kD-tree data structure, is adaptive and efficient in arbitrary dimensions. We show that our technique leads to dramatically improved convergence over naive jumps in an RJMCMC, and compare it ...

  10. An efficient interpolation technique for jump proposals in reversible-jump Markov chain Monte Carlo calculations.

    Science.gov (United States)

    Farr, W M; Mandel, I; Stevens, D

    2015-06-01

    Selection among alternative theoretical models given an observed dataset is an important challenge in many areas of physics and astronomy. Reversible-jump Markov chain Monte Carlo (RJMCMC) is an extremely powerful technique for performing Bayesian model selection, but it suffers from a fundamental difficulty and it requires jumps between model parameter spaces, but cannot efficiently explore both parameter spaces at once. Thus, a naive jump between parameter spaces is unlikely to be accepted in the Markov chain Monte Carlo (MCMC) algorithm and convergence is correspondingly slow. Here, we demonstrate an interpolation technique that uses samples from single-model MCMCs to propose intermodel jumps from an approximation to the single-model posterior of the target parameter space. The interpolation technique, based on a kD-tree data structure, is adaptive and efficient in modest dimensionality. We show that our technique leads to improved convergence over naive jumps in an RJMCMC, and compare it to other proposals in the literature to improve the convergence of RJMCMCs. We also demonstrate the use of the same interpolation technique as a way to construct efficient 'global' proposal distributions for single-model MCMCs without prior knowledge of the structure of the posterior distribution, and discuss improvements that permit the method to be used in higher dimensional spaces efficiently.

  11. Developing countries use music videos to promote teen sexual restraint.

    Science.gov (United States)

    Pemberton, M

    1991-12-15

    The Center for Communications Programs of the Johns Hopkins University has successfully produced and aired songs and music videos promoting teenage sexual restraint in developing countries. Entertaining music videos convey accurate messages to target audiences more effectively than teachers and doctors are able. In addition to successes in the Philippines and Nigeria, overwhelming success has been met with Wait, a video with Latin American pop start Tatiana and Johnny. A hit in 11 Latin American countries reaching 1 in Mexico, the video received 1 million hour s free air time. Passionate, powerful, and persuasive, these videos have prompted increased contraceptive use in countries where they have been aired. The Center's videos and songs have proved popular and profitable in a competitive market of ideas, earning 3-4 times their production costs. Accordingly, health experts from Johns Hopkins University recognize the potential role of these productions in preventing AIDS and unwanted pregnancies in other settings. Where Baltimore leads the U.S. in teen pregnancies, the Center would like to air soap opera on sexual responsibility. Production costs in the U.S. are, however, 10 times higher than in developing countries. With the collaboration of media executives, significant financial and social rewards could result from such a production.

  12. Drive Alive: Teen Seat Belt Survey Program

    Directory of Open Access Journals (Sweden)

    Loftin, Laurel

    2010-08-01

    Full Text Available Objective: To increase teen seat belt use among drivers at a rural high school by implementing the Drive Alive Pilot Program (DAPP, a theory-driven intervention built on highway safety best practices.Methods: The first component of the program was 20 observational teen seat belt surveys conducted by volunteer students in a high school parking lot over a 38-month period before and after the month-long intervention. The survey results were published in the newspaper. The second component was the use of incentives, such as gift cards, to promote teen seat belt use. The third component involved disincentives, such as increased police patrol and school policies. The fourth component was a programmatic intervention that focused on education and media coverage of the DAPP program.Results: Eleven pre-intervention surveys and nine post-intervention surveys were conducted before and after the intervention. The pre- and post-intervention seat belt usage showed significant differences (p<0.0001. The average pre-intervention seat belt usage rate was 51.2%, while the average post-intervention rate was 74.5%. This represents a percentage point increase of 23.3 in seat belt use after the DAPP intervention.Conclusion: Based on seat belt observational surveys, the DAPP was effective in increasing seat belt use among rural high school teenagers. Utilizing a theory-based program that builds on existing best practices can increase the observed seat belt usage among rural high school students. [West J Emerg Med. 2010; 11(3: 280-283.

  13. What’s Behind Teen Obesity?

    Institute of Scientific and Technical Information of China (English)

    姜丽萍

    2003-01-01

    选注者言:少年肥胖是一个世界难题。本文的分析让人眼睛一亮,到底肥胖的现象后面藏匿着什么问题?本文提出了一个治本的办法,看来抽象,其实重要!那就是:…environmental,cultural,contextual and community factors also needto be addressed to find solutions for teen obesity in the United States.

  14. Hispanic Teen Pregnancy and Birth Rates: Looking Behind the Numbers. Child Trends Research Brief. Publication #2005-01

    Science.gov (United States)

    Ryan, Suzanne; Franzetta, Kerry; Manlove, Jennifer

    2005-01-01

    This research brief focuses on the birth, pregnancy, contraceptive, and relationship behaviors of Hispanic teens because they represent an important risk group. Teen pregnancy and birth rates for U.S. teens have declined dramatically in recent years. Yet for Hispanic teens, reductions in teen pregnancy and childbearing have lagged behind that of…

  15. Feeding practice and influence on selected blood parameters in show jumping horses competing in Switzerland.

    Science.gov (United States)

    Brunner, J; Liesegang, A; Weiss, S; Wichert, B

    2015-08-01

    The aim of this study was to compare the nutritional management of show jumping horses in practice with recommendations from the literature. Additionally, the effects of these feeding practices on several blood metabolic parameters before and after exercise were studied. Blood samples were collected in the field from 27 different horses at 71 trials on the level M1 to S2 show jumping competitions in Switzerland and questionnaires on feeding practice of the studied horses were evaluated. The questionnaires revealed that during training and on tournament days horses received on average 3.1 kg of concentrate per day (min. 2.0 kg, max. 6.6 kg) divided into two to three meals. The horses were fed on average 6.9 kg of roughage per day (min. 4.0 kg, max. 13.0 kg). Additionally, it was observed that the horses received the last meal on average 6 h 10 min (min. 1 h 50 min, max. 12 h 30 min) before the start of the first show jumping turn, respectively, 7 h 30 min (min 1 h 50 min, max. 13 h 0 min) before the second turn. Seven horses (35%) had access to hay waiting in the trailer between two turns. The statistical analysis revealed no significant influence of the concentrate feeding time point on lactate, triglyceride and insulin levels, but a significant influence on free fatty acids (FFA) and blood glucose concentrations. Roughage feeding of the show jumping horses 2-4 h prior to exercise revealed the most remarkable changes in blood parameters during the show jumping course. These results received under field conditions should be approved in future under standardized conditions.

  16. Attentional Focus Effects in Standing Long Jump Performance: Influence of a Broad and Narrow Internal Focus.

    Science.gov (United States)

    Becker, Kevin A; Smith, Peter J K

    2015-07-01

    The content of instructions that strength coaches give can have a significant impact on how an athlete or client performs. Research on motor learning has shown an advantage of instructions focusing on the effects of movements (external focus) over those focusing on the movements themselves (internal focus) in the performance of motor skills. Internally focused cues are abundant in coaching, therefore the purpose of this study was to test whether some internally focused cues might be more helpful than others. Participants (68) were randomly assigned to either an external focus (EX), broad internal focus (B-IN), narrow internal focus (N-IN), or a control group (CON), and performed 5 standing long jumps. All groups were instructed that the goal was to jump as far as possible. In addition, the EX group was told to "jump as far past the start line as possible." The B-IN group was told to "use your legs." The N-IN group was told to "extend your knees as rapidly as possible," and the CON group received no additional instruction. An analysis of covariance showed that the EX group (198.09 ± 31.89 cm) jumped significantly farther than both the B-IN group (173.74 ± 35.36 cm), p = 0.010 and the N-IN group (178.53 ± 31.17 cm), p = 0.049, with no group different from the CON group. The results suggest that a broad internal focus is no more effective than a narrow internal focus, and that an external focus leads to the greatest jump distance. Strength and conditioning professionals should carefully word their instructions to induce an external focus of attention whenever possible.

  17. The Mechanics and Trajectory Control in Locust Jumping

    Institute of Scientific and Technical Information of China (English)

    Longbao Han; Zhouyi Wang; Aihong Ji; Zhendong Dai

    2013-01-01

    Locusts (Locusta migratoria manilensis) are characterised by their flying ability and abiding jump ability.Research on the jumping mechanics and behavior of locusts plays an important role in elucidating the mechanism of hexapod locomotion.The jump gestures of locusts were observed using high-speed video camera at 250 fps.The reaction forces of the hindlegs were measured using two three-dimensional sensors,in case the two hindlegs attached on separated sensor plates.The jump gestures and reaction forces were used to illustrate the locust jumping mechanism.Results show that the trajectory control is achieved by rapid rolling and yawing movements of the locust body,caused by the forelegs,midlegs and hindlegs in different jumping phases.The final jump trajectory was not determined until hind tarsi left platform.The horizontal co-impulse between two hindlegs might play a key role in jump stability and accuracy.Besides,the angle between two hindlegs affects the control of jump trajectory but has a little effect on the elevation angle of a jump,which is controlled mechanically by the initial position of the hindlegs.This research lays the groundwork for the probable design and development of biomimetic robotics.

  18. Risky Teen Driving in a Rural Southern State.

    Science.gov (United States)

    Monroe, Kathy; Hardwick, William; Lawson, Victoria; Nichols, Elizabeth; Nichols, Michele; King, William D

    2017-05-01

    Alabama is one of the five US states with the highest teen driving mortality. We recruited teen drivers to participate in a questionnaire regarding high-risk driving behaviors. Teens were recruited from a large county school system to participate in a voluntary anonymous survey. Questions were taken in part from the National Youth Risk Behavior Survey. Descriptive statistics and odds ratios with 95% confidence intervals were calculated. A total of 1023 teen drivers participated (46% boys, 47% African American, 39% white, 6% Latino, and 7% other). In all, 526 students (52%) reported inconsistent seat belt use. Half of the teens surveyed reported using a cellular telephone while driving within the past 30 days (51%); 10% admitted to driving after drinking alcoholic beverages in the past 30 days, with 23% saying they had ridden with a driver who had been drinking. High-risk teen driving behaviors were reported by many of the participants in our study. The majority of teens surveyed do not routinely wear seatbelts. Common misperceptions still exist regarding seatbelts and should be a focus of future education. Future research should focus on parental behaviors and correcting misperceptions of young drivers.

  19. Lean start-up

    DEFF Research Database (Denmark)

    Rasmussen, Erik Stavnsager; Tanev, Stoyan

    2016-01-01

    The risk of launching new products and starting new firms is known to be extremely high. The Lean Start-up approach is a way of reducing these risks and enhancing the chances for success by validating the products and services in the market with customers before launching it in full scale. The main...... point is to develop a Minimum Viable Product that can be tested by potential customers and then pivot the idea if necessary around these customer evaluations. This iterative process goes through a number of stages with the purpose of validating the customers’ problems, the suggested solution...

  20. Induction motor starting current

    Energy Technology Data Exchange (ETDEWEB)

    Arneaud, J.M.; Langman, R.A. [Tasmania Univ., Hobart, TAS (Australia)

    1995-12-31

    Large errors may occur if leakage path saturation is neglected when reduced-voltage test results are used to predict the direct-on-line starting current of induction motors. The results of applying three existing and two new methods for starting current prediction are compared with test data from 52 motors. A quantitative assessment is made of the probable reduction in error that would be achieved by increasing the number of available sets of reduced-voltage, locked rotor test results or by including slot design data. Guidelines are given for selecting an appropriate predictive method. (author). 4 tabs., 1 fig., 6 refs.

  1. Correlates of cyber dating abuse among teens.

    Science.gov (United States)

    Zweig, Janine M; Lachman, Pamela; Yahner, Jennifer; Dank, Meredith

    2014-08-01

    Recent advancements in technology (e.g., social networking, texting) have created new ways for dating youth to relate to one another, including in abusive ways via "cyber dating abuse." Cyber dating abuse is a form of teen dating violence that overlaps with other types of abuse (e.g., psychological) but also has several unique characteristics. Given the phenomenon's limited presence in dating violence literature, we focus on identifying how experiencing cyber dating abuse relates to youths' individual behaviors and experiences (e.g., substance use, sexual activity), psychosocial adjustment, school connection, family relationships, and partner relationships. A total of 3,745 youth (52% female, 74% White) in three northeastern states participated in the survey and reported currently being in a dating relationship or having been in one during the prior year. We found that experiences of cyber dating abuse were most significantly correlated with being female, committing a greater variety of delinquent behaviors, having had sexual activity in one's lifetime, having higher levels of depressive symptoms, and having higher levels of anger/hostility. Further, cyber dating abuse appeared somewhat more strongly related to depressive symptoms and delinquency than did other forms of teen dating violence and abuse.

  2. Gaming Against Violence: A Grassroots Approach to Teen Dating Violence.

    Science.gov (United States)

    Crecente, Drew

    2014-08-01

    Teen dating violence is a pervasive problem that affects millions of adolescents worldwide. Although there have been various approaches to addressing this problem, using videogames had not been employed before 2008, when Jennifer Ann's Group, an Atlanta, GA-based nonprofit organization, created an annual competition. The Life.Love. Game Design Challenge rewards game developers for creating videogames about teen dating violence without using any violence in the games themselves. The resulting videogames have increased awareness about teen dating violence and provided educational information to assist adolescents, parents, and teachers in identifying abusive relationships.

  3. Teen financial literacy evaluated to develop outreach materials

    OpenAIRE

    Varcoe, Karen; Peterson, Shirley; Go, Charles; Johns, Margaret; René-Fitch, Paula; Powell, Carol; Costello, Connie

    2002-01-01

    Teenagers have access to and spend a great deal of money each year, yet research indicates that their financial literacy is low. Many curricula for teaching money management exist, but we do not know if we are teaching teens what they want to know in a way that they want to learn. This study, conducted by the Money 2000+ for Teens Workgroup of the UC Division of Agriculture and Natural Resources, sought to find out what teens want to know about financial management. Questionnaires were admini...

  4. Promoting balance and jumping skills in children with Down syndrome.

    Science.gov (United States)

    Wang, Wai-Yi; Ju, Yun-Huei

    2002-04-01

    The purpose of this study was to investigate the changes in balance and qualitative and quantitative jumping performances by 20 children with Down syndrome (3 to 6 years) on jumping lessons. 30 typical children ages 3 to 6 years were recruited as a comparison group. Before the jumping lesson, a pretest was given subjects for balance and jumping skill measures based on the Motor Proficiency and Motor Skill Inventory, respectively. Subjects with Down syndrome received 3 sessions on jumping per week for 6 weeks but not the typical children. Then, a posttest was administered to all subjects. Analysis of covariance showed the pre- and posttest differences on scores for floor walk, beam walk, and horizontal and vertical jumping by subjects with Down syndrome were significantly greater than those for the typical children.

  5. Theoretical Modeling of Internal Hydraulic Jump in Density Currents

    CERN Document Server

    Firoozabadi, Bahar; Aryanfar, Asghar; Afshin, Hossein

    2013-01-01

    In this paper, we propose an analytical framework for internal hydraulic jumps. Density jumps or internal hydraulic jumps occur when a supper critical flow of water discharges into a stagnant layer of water with slightly different density. The approach used here is control volume method which is also used to analyze ordinary hydraulic jumps. The important difference here is that entrainment is taken into account. Using conservation equations with the aid of some simplifying assumptions we come to an equation that gives jump downstream height as function of jump upstream characteristics and the entrainment. To determine the magnitude of downstream height we use an experimental equation for calculating the entrainment. Finally we verify our framework by comparing the height that we gain from the derived equation with some experimental data.

  6. A-jump in horizontal inverted semicircular open channels

    Directory of Open Access Journals (Sweden)

    I.M.H. Rashwan

    2013-12-01

    Full Text Available The hydraulic jump is a transitional state from supercritical to subcritical flow. The phenomenon of the hydraulic jump has been widely studied because of its frequent occurrence in nature and because of its uses in many practical applications. In the present study the momentum principle is used to derive an equation expressed the hydraulic jump (A-jump occurred in a short horizontal reach of an inverted semicircular open channel. The derived equation indicates that the initial water depth and the tail water depth (conjugate depths are functions of the critical water depth. Various elements of the hydraulic jump are expressed in dimensionless case. The procedure of dimensionless ratios described in the present paper can be used to determine various elements of A-jump in an inverted semicircular channel when either the discharge and the relative initial depth (or tail water depth is known or the discharge and the relative dissipated energy are known.

  7. A Jump-Diffusion Model with Stochastic Volatility and Durations

    DEFF Research Database (Denmark)

    Wei, Wei; Pelletier, Denis

    Market microstructure theories suggest that the durations between transactions carry information about volatility. This paper puts forward a model featuring stochastic volatility, stochastic conditional duration, and jumps to analyze high frequency returns and durations. Durations affect price...... jumps in two ways: as exogenous sampling intervals, and through the interaction with volatility. We adopt a bivariate Ornstein-Ulenbeck process to model intraday volatility and conditional duration. We develop a MCMC algorithm for the inference on irregularly spaced multivariate processes with jumps....... The algorithm provides smoothed estimates of the latent variables such as spot volatility, conditional duration, jump times, and jump sizes. We apply this model to IBM data and find that volatility and conditional duration are interdependent. We also find that jumps play an important role in return variation...

  8. ATLAS starts moving in

    CERN Multimedia

    2004-01-01

    The first large active detector component was lowered into the ATLAS cavern on 1 March. It consisted of the 8 modules forming the lower part of the central barrel of the tile hadronic calorimeter. The work of assembling the barrel, which comprises 64 modules, started the following day.

  9. A New Start

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Goodwill to the Islamic world and willingness to mend ties highlight Barack Obama’s new Middle East policy u.S. President Barack Obama started to implement his new Middle East policy soon after he assumed office. He paid a

  10. Getting started with UDOO

    CERN Document Server

    Palazzetti, Emanuele

    2015-01-01

    If you are an Android developer who wants to learn how to use UDOO to build Android applications that are capable of interacting with their surrounding environment, then this book is ideal for you. Learning UDOO is the next great step to start building your first real-world prototypes powered by the Android operating system.

  11. Start-Up Capital

    NARCIS (Netherlands)

    I. Verheul (Ingrid); A.R. Thurik (Roy)

    2000-01-01

    textabstractFemale and male entrepreneurs differ in the way they finance their businesses. This can be attributed to the type of business and the type of management and experience (indirect effect). Female start-ups may also experience other barriers based upon discriminatory effects (direct

  12. Robust Stabilization for Uncertain Linear Delay Markow Jump System

    Institute of Scientific and Technical Information of China (English)

    钟麦英; 汤兵勇; 黄小原

    2001-01-01

    Markov jump linear systems are defined as a family of linear systems with randomly Markov jumping parameters and are used to model systems subject to failures or changes in structure. The robust stabilization problem of jump linear delay system with umcerratnty was studied. By using of linear matrix inequalities, the existence conditions of robust stabilizing and the state feedback controller designing methods are also presented and proved. Finally, an illustrated example shows the effectiveness of this approach.

  13. Approximation of Jump Diffusions in Finance and Economics

    OpenAIRE

    Nicola Bruti-Liberati; Eckhard Platen

    2006-01-01

    In finance and economics the key dynamics are often specified via stochastic differential equations (SDEs) of jump-diffusion type. The class of jump-diffusion SDEs that admits explicit solutions is rather limited. Consequently, discrete time approximations are required. In this paper we give a survey of strong and weak numerical schemes for SDEs with jumps. Strong schemes provide pathwise approximations and therefore can be employed in scenario analysis, filtering or hedge simulation. Weak sc...

  14. Times and Sizes of Jumps in the Mexican Interest Rate

    OpenAIRE

    José Antonio Núñez Mora; Arturo Lorenzo Valdés

    2008-01-01

    This paper examines the role of jumps in a continuous-time short-term interest rate model for Mexico. A filtering algorithm provides estimates of jumps times and sizes in the time series of Mexican cetes for the 1998-2006 period. The empirical results indicate that the inclusion of jumps in the diffusion model represents a better alternative than not to include them.

  15. Parenting behaviors during risky driving by teens with attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Schatz, Nicole K; Fabiano, Gregory A; Morris, Karen L; Shucard, Jennifer M; Leo, Brittany A; Bieniek, Courtney

    2014-03-01

    Parenting practices for teen drivers with ADHD were observed via a video monitor installed in vehicles. All teens had recently completed a driver education course and were in the driving permit stage of a graduated driver-licensing program. Parent behaviors were coded during drives when teens were driving safely and during drives when teens engaged in risky driving. The overall frequency of positive parenting strategies was low, regardless of whether teens drove safely or engaged in risky driving. Although the rate of negative feedback was also low, parents engaged in significantly more criticism and were rated by an observer to appear angrier when teens were driving in a risky manner. No other differences in parent behaviors associated with the quality of teen driving were observed. The inconsistencies between observed parenting behaviors and those parenting practices recommended as effective with teens with ADHD are discussed. The need for further research addressing effective strategies for teaching teens with ADHD to drive is highlighted.

  16. Down With Teen Pregnancy, Up With Mobility: Teen Pregnancy Prevention Efforts in Gaston County, North Carolina.

    Science.gov (United States)

    Dobbins, Christopher C; Kenney, Brittain N; Meier, Carrie E; Taormina, Velma V

    Unintended pregnancies are typically associated with poor health outcomes for mothers and babies, and they also limit the social mobility of women and their families. Gaston County has achieved great success in reducing both teen pregnancies and unintended pregnancies among low-income women through the Gaston Youth Connected project and the local health department's push to increase accessibility to long-acting reversible contraception. Reductions in the racial disparities in teen pregnancy rates, higher graduation rates for females, and fewer pregnancies among low-income women all indicate a potential for better reproductive health to increase the social mobility of Gaston County women. The ability to clearly connect health outcomes to long-term social improvements helps create sustainable community buy-in and should be a priority in public health initiatives.

  17. Multiobjective Optimization Methodology A Jumping Gene Approach

    CERN Document Server

    Tang, KS

    2012-01-01

    Complex design problems are often governed by a number of performance merits. These markers gauge how good the design is going to be, but can conflict with the performance requirements that must be met. The challenge is reconciling these two requirements. This book introduces a newly developed jumping gene algorithm, designed to address the multi-functional objectives problem and supplies a viably adequate solution in speed. The text presents various multi-objective optimization techniques and provides the technical know-how for obtaining trade-off solutions between solution spread and converg

  18. Planar jumping-drop thermal diodes

    Science.gov (United States)

    Boreyko, Jonathan B.; Zhao, Yuejun; Chen, Chuan-Hua

    2011-12-01

    Phase-change thermal diodes rectify heat transport much more effectively than solid-state ones, but are limited by either the gravitational orientation or one-dimensional configuration. Here, we report a planar phase-change diode scalable to large areas with an orientation-independent diodicity of over 100, in which water/vapor is enclosed by parallel superhydrophobic and superhydrophilic plates. The thermal rectification is enabled by spontaneously jumping dropwise condensate which only occurs when the superhydrophobic surface is colder than the superhydrophilic surface.

  19. Understanding the physics of bungee jumping

    OpenAIRE

    Heck, A; Uylings, P.; Kędzierska, E.

    2010-01-01

    Changing mass phenomena like the motion of a falling chain, the behaviour of a falling elastic bar or spring, and the motion of a bungee jumper surprise many a physicist. In this article we discuss the first phase of bungee jumping, when the bungee jumper falls, but the bungee rope is still slack. In instructional material this phase is often considered a free fall, but when the mass of the bungee rope is taken into account, the bungee jumper reaches acceleration greater than g. This result i...

  20. Quantifying show jumping horse rider expertise using IMUs.

    Science.gov (United States)

    Patterson, M; Doyle, J; Cahill, E; Caulfield, B; McCarthy Persson, U

    2010-01-01

    Horse rider ability has long been measured using horse performance, competition results and visual observation. Scientific methods of measuring rider ability on the flat are emerging such as measuring position angles and harmony of the horse-rider system. To date no research has quantified rider ability in show jumping. Kinematic analysis and motion sensors have been used in sports other than show jumping to measure the quality of motor control patterns in humans. The aim of this study was to quantify rider ability in show jumping using body-mounted IMUs. Preliminary results indicate that there are clear differences in experienced and novice riders during show jumping.

  1. Distance perception in the spiny mouse Acomys cahirinus: vertical jumping.

    Science.gov (United States)

    Goldman, M; Skolnick, A J; Hernandez, T P; Tobach, E

    1992-12-01

    Acomys cahirinus, a precocial muroid, that has shown precise jumping in the natural habitat, did not jump from 25 cm in a laboratory situation. To investigate this further, A. cahirinus were observed jumping from platforms at two different heights, onto different sized checkered substrates and from a visual cliff. Adult animals discriminated between platforms that were 6.4 cm and 25.4 cm above the substrate and between small and large checkered patterns on the floor. Most adult animals and neonates jumped down on the shallow side of the visual cliff. Animals developed individual patterns of jumping over a series of trials, with some jumping often, some rarely, and others jumping only from the low platform. Good distance perception was indicated when they did not jump from heights, and by their making appropriate postural adjustment when they did jump from heights and landed without mishap. Different spacing of trials indicated that height was a more effective stimulus for animals which had all four conditions on the same day, while floor pattern was more effective for animals with each of the four conditions on a separate day.

  2. Long memory behavior of returns after intraday financial jumps

    Science.gov (United States)

    Behfar, Stefan Kambiz

    2016-11-01

    In this paper, characterization of intraday financial jumps and time dynamics of returns after jumps is investigated, and will be analytically and empirically shown that intraday jumps are power-law distributed with the exponent 1 finance, it is important to be able to distinguish between jumps and continuous sample path price movements, and this can be achieved by introducing a statistical test via calculating sums of products of returns over small period of time. In the case of having jump, the null hypothesis for normality test is rejected; this is based on the idea that returns are composed of mixture of normally-distributed and power-law distributed data (∼ 1 /r 1 + μ). Probability of rejection of null hypothesis is a function of μ, which is equal to one for 1 high returns after jumps are the effect; we show that returns caused by jump decay as power-law distribution. To test this idea empirically, we average over the time dynamics of all days; therefore the superposed time dynamics after jump represent a power-law, which indicates that there is a long memory with a power-law distribution of return after jump.

  3. Biomechanics research in ski jumping, 1991-2006.

    Science.gov (United States)

    Schwameder, Hermann

    2008-01-01

    In this paper, I review biomechanics research in ski jumping with a specific focus on publications presented between 1991 and 2006 on performance enhancement, limiting factors of the take-off, specific training and conditioning, aerodynamics, and safety. The first section presents a brief description of ski jumping phases (in-run, take-off, early flight, stable flight, and landing) regarding the biomechanical and functional fundamentals. The most important and frequently used biomechanical methods in ski jumping (kinematics, ground reaction force analyses, muscle activation patterns, aerodynamics) are summarized in the second section. The third section focuses on ski jumping articles and research findings published after the establishment of the V-technique in 1991, as the introduction of this technique has had a major influence on performance enhancement, ski jumping regulations, and the construction of hill profiles. The final section proposes topics for future research in the biomechanics of ski jumping, including: take-off and early flight and the relative roles of vertical velocity and forward somersaulting angular momentum; optimal jumping patterns utilizing the capabilities of individual athletes; development of kinematic and kinetic feedback systems for hill jumps; comparisons of simulated and hill jumps; effect of equipment modifications on performance and safety enhancement.

  4. Competitive Lotka-Volterra Population Dynamics with Jumps

    CERN Document Server

    Bao, Jianhai; Yin, Geroge; Yuan, Chenggui

    2011-01-01

    This paper considers competitive Lotka-Volterra population dynamics with jumps. The contributions of this paper are as follows. (a) We show stochastic differential equation (SDE) with jumps associated with the model has a unique global positive solution; (b) We discuss the uniform boundedness of $p$th moment with $p>0$ and reveal the sample Lyapunov exponents; (c) Using a variation-of-constants formula for a class of SDEs with jumps, we provide explicit solution for 1-dimensional competitive Lotka-Volterra population dynamics with jumps, and investigate the sample Lyapunov exponent for each component and the extinction of our $n$-dimensional model.

  5. pH jump induced α-helix folding.

    Directory of Open Access Journals (Sweden)

    Donten M. L.

    2013-03-01

    Full Text Available pH can be used to impact the folding equilibrium of peptides and proteins. This fact is utilized, similarly to temperature jumps, in pH jump experiments employing laser time-resolved spectroscopy to study the function and structural dynamics of these molecules. Here the application of pH jumps in folding experiments was investigated. Experiments with poly-L-glutamic acid alpha-helix formation shown the critical aspects of pH jump experiments and yielded direct information about the folding kinetics monitored with the amide I IR band.

  6. Effect of drop jump technique on the reactive strength index

    Directory of Open Access Journals (Sweden)

    Struzik Artur

    2016-09-01

    Full Text Available The basic drill of plyometric training aimed at improving lower limb power and jump height is a drop jump. This exercise can be performed using different techniques, which substantially affects jump variables. Therefore, the aim of this study was to compare the values of the reactive strength index (RSI for countermovement drop jumps (CDJs and bounce drop jumps (BDJs. The study was carried out in a group of 8 male youth basketball players. The tests were conducted using the AMTI BP600900 force plate to measure ground reaction forces and the Noraxon MyoMotion system to record kinematic data. Each player performed two CDJs and two BDJs from the height of 15, 30, 45 and 60 cm. The RSI was calculated as a ratio of jump height and contact time. Moreover, the RSI was determined for the amortization and take-off phases separately. Significant differences (p < 0.05 between RSI values for CDJs and BDJs were recorded for jumps from 30, 45 and 60 cm. Differences in RSI values for jumps from 15 cm were not significant. Furthermore, CDJ height values were significantly higher (p < 0.05 than the values recorded for BDJs. Times of contact, amortization and take-off during BDJs were significantly shorter (p < 0.05 than the respective values obtained for CDJs. Therefore, the use of the RSI to monitor plyometric training should be based on the drop jump technique that is commonly performed by basketball players.

  7. Development of a Minimally Actuated Jumping-Rolling Robot

    Directory of Open Access Journals (Sweden)

    Thanhtam Ho

    2015-04-01

    Full Text Available This paper presents development of a hybrid mobile robot in order to take advantage of both rolling and jumping locomotion on the ground. According to the unique design of the mechanism, the robot is able to execute both jumping and rolling skilfully by using only one DC motor. Changing the centre of gravity enables rolling of the robot and storage of energy is utilized for jumping. Mechanism design and control logic are validated by computer simulation. Simulation results show that the robot can jump nearly 1.3 times its diameter and roll at the speed of 3.3 times its diameter per second.

  8. Exploiting knowledge of jump-up and jump-down frequencies to determine the parameters of a Duffing oscillator

    Science.gov (United States)

    Ramlan, Roszaidi; Brennan, Michael J.; Kovacic, Ivana; Mace, Brian R.; Burrow, Stephen G.

    2016-08-01

    This work concerns the application of certain non-linear phenomena - jump frequencies in a base-excited Duffing oscillator - to the estimation of the parameters of the system. First, approximate analytical expressions are derived for the relationships between the jump-up and jump-down frequencies, the damping ratio and the cubic stiffness coefficient. Then, experimental results, together with the results of numerical simulations, are presented to show how knowledge of these frequencies can be exploited.

  9. Thin Books, Big Problems: Realism and the Reluctant Teen Reader.

    Science.gov (United States)

    Jones, Patrick

    1994-01-01

    Discusses the way that realistic fictional narratives are an effective reading material for adolescents who are uninterested in reading. Provides an extensive list of short realistic novels that all tackle real issues faced by today's teen. (HB)

  10. Hearing Loss Rates Holding Steady for U.S. Teens

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_167456.html Hearing Loss Rates Holding Steady for U.S. Teens: Study Vaccine ... via earphones than ever before, but rates of hearing loss have not increased. Still, "the overall take-home ...

  11. CDC Vital Signs: Preventing Pregnancies in Younger Teens

    Science.gov (United States)

    ... younger teens made a reproductive health visit for birth control services in the past year. Doctors and nurses could use this opportunity to discuss advantages and disadvantages of different contraceptive methods and the ...

  12. Painkillers for Teen Athletes Won't Spur Addiction

    Science.gov (United States)

    ... suggests that prescribing opioids to teens after a sports injury may lead some of them to become heroin ... to painkiller abuse, Veliz recommended more study on sports injury and pain management. Such studies help expand knowledge ...

  13. Soft Contact Lenses Safe for Kids and Teens, Review Finds

    Science.gov (United States)

    ... news release, Bullimore said the findings should reassure parents about the safety of soft contacts in children and teens. They may improve young people's self-esteem and quality of life, and have been shown ...

  14. Teen Sexual Health: MedlinePlus Health Topic

    Science.gov (United States)

    ... Health (Nemours Foundation) Teenage Sexuality (American Academy of Pediatrics) Also in Spanish Latest News Privacy Concerns Keep Some Young Americans ... Spanish Expect Respect: Healthy Relationships (American Academy of Pediatrics) Also in Spanish Helping Teens Resist Sexual Pressure (American Academy of ...

  15. E-Cigarettes Lead to 'Real' Smoking by Teens: Review

    Science.gov (United States)

    ... fullstory_166899.html E-Cigarettes Lead to 'Real' Smoking by Teens: Review But one public health expert ... likely as their non-vaping counterparts to begin smoking traditional cigarettes, a new review suggests. "E-cigarette ...

  16. Obesity More Common Among Teens with Autism: Study

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161525.html Obesity More Common Among Teens With Autism: Study Addressing ... new study suggests. The researchers noted that childhood obesity could have long-term health consequences for those ...

  17. Fewer U.S. Teens Are Boozing It Up

    Science.gov (United States)

    ... fullstory_165831.html Fewer U.S. Teens Are Boozing It Up Study finds frequent binge drinking among adolescents ... U.S. National Institute on Alcohol Abuse and Alcoholism. It will be published online May 22 in the ...

  18. Tips for Teens with Diabetes: What Is Diabetes?

    Science.gov (United States)

    ... for Teens: Lower Your Risk for Type 2 Diabetes When Your Child Is Diagnosed with Diabetes: Parents’ Questions for the ... the chances of both the mother and her child getting diabetes later on. Why should I take care of ...

  19. Same-Sex Marriage Laws Tied to Fewer Teen Suicides

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_163674.html Same-Sex Marriage Laws Tied to Fewer Teen Suicides Perceived ... A new study links the approval of same-sex marriage in American states to lower rates of ...

  20. Outcomes of teen parenting programs in New Mexico.

    Science.gov (United States)

    Philliber, Susan; Brooks, Linda; Lehrer, Linda Phillips; Oakley, Merry; Waggoner, Sharon

    2003-01-01

    Although teen pregnancy rates in the U.S. have recently declined, the need for programs for pregnant and parenting teens remains. This report presents information from 53 programs that served pregnant and parenting teens in New Mexico between 1997 and 2000. Data on 3,194 teens, including their characteristics, the services they received, and several key outcomes, are examined. These data indicate that the programs were successful in promoting educational attainment as well as gains in employment. Prevalence of late prenatal care and low birth weight babies was lower than statewide averages, and the rate of repeat pregnancy was lower than that reported by many other programs. How these programs achieved these results is discussed.

  1. Teen Screen: Take a Walk on the Wild Side.

    Science.gov (United States)

    Flowers, Sarah

    2002-01-01

    Reviews seven videos that involve some aspect of extreme sports, feature loud rock music, and are popular with teens. Includes snowboarding, Gravity Games, BMX bikes, skateboarding, and skydiving. (LRW)

  2. Abstinence First: Teen Birth Control Decisions (Version A)

    National Research Council Canada - National Science Library

    Kimberly L Paone

    2003-01-01

      Gr 7-12-A multicultural cast of teens of both genders provide information about every form of birth control available including spermicide, male and female condoms, diaphragms, cervical caps, the sponge, LU.D...

  3. Knowing Their Breast Cancer Risk May Empower Teens

    Science.gov (United States)

    ... medlineplus.gov/news/fullstory_161233.html Knowing Their Breast Cancer Risk May Empower Teens Greater self-esteem noted in ... interviewed to assess their mental health, perception of breast cancer risk, and levels of distress about breast cancer. The ...

  4. U.S. Teen Births Hit Another Record Low: CDC

    Science.gov (United States)

    ... Academy of Pediatrics. Teen pregnancy prevention programs and sex education have also played a role, Albert said. And ... challenges of parenting quite real to them -- almost sex education for the 21st century," he said. Another expert ...

  5. Polycystic Ovary Syndrome (PCOS): A Guide for Teens

    Science.gov (United States)

    ... of 10 women has PCOS. What is PCOS? Polycystic ovary syndrome (PCOS) is a hormone imbalance that can cause irregular periods, unwanted hair growth, and acne. PCOS begins during a girl’s teen years and ...

  6. Teen dating violence: building a research program through collaborative insights.

    Science.gov (United States)

    Mulford, Carrie F; Blachman-Demner, Dara R

    2013-06-01

    The National Institute of Justice (NIJ) has an emerging portfolio of research in the area of teen dating violence (also known as adolescent relationship abuse). This article begins with a discussion of the developments that prompted NIJ to focus on teen dating violence. Next, the article highlights specific accomplishments and contributions that NIJ has made to helping develop knowledge and scientific understanding of adolescent relationship abuse, particularly around the prevention of teen dating violence perpetration and victimization. This is followed by a presentation of some of the key findings from NIJ-funded research. We then move to a discussion of some of the complex issues around definition, measurement and research methods and how NIJ has been involved in addressing those issues. The article concludes with some thoughts about the intersection of teen dating violence research, policy, and practice and highlights several research gaps that are in need of additional attention.

  7. When Being Overweight Is a Health Problem (For Teens)

    Science.gov (United States)

    ... A Week of Healthy Breakfasts Shyness When Being Overweight Is a Health Problem KidsHealth > For Teens > When ... impact a person's entire quality of life. Defining Overweight When people eat more calories than they burn ...

  8. Teen Cyberbullies More Apt to Be Friends Than Strangers

    Science.gov (United States)

    ... 22, 2016 SATURDAY, Aug. 20, 2016 (HealthDay News) -- Cyberbullying among teens is highly likely to involve current ... suburb. About 17 percent had been involved with cyberbullying in the previous week, the study found. Nearly ...

  9. Getting started with JUCE

    CERN Document Server

    Robinson, Martin

    2013-01-01

    his book is a fast-paced, practical guide full of step-by-step examples which are easy to follow and implement.This book is for programmers with a basic grasp of C++. The examples start at a basic level, making few assumptions beyond fundamental C++ concepts. Those without any experience with C++ should be able to follow and construct the examples, although you may need further support to understand the fundamental concepts.

  10. Getting started with Simulink

    CERN Document Server

    Zamboni, Luca

    2013-01-01

    This practical and easy-to-understand learning tutorial is one big exciting exercise for students and engineers that are always short on their schedules and want to regain some lost time with the help of Simulink.This book is aimed at students and engineers who need a quick start with Simulink. Though it's not required in order to understand how Simulink works, knowledge of physics will help the reader to understand the exercises described.

  11. Getting started with Hazelcast

    CERN Document Server

    Johns, Mat

    2013-01-01

    Written as a step-by-step guide, Getting Started with Hazelcast will teach you all you need to know to make your application data scalable.This book is a great introduction for Java developers, software architects, or developers looking to enable scalable and agile data within their applications. You should have programming knowledge of Java and a general familiarity with concepts like data caching and clustering.

  12. Dealing with teen-age pregnancy.

    Science.gov (United States)

    Dempsey, P L

    1991-01-01

    The author finds that teenage pregnancy is more complicated than access to contraception or abortion. At risk teenagers are not identifiable, only at risk factors such as isolation, lack of perception of future opportunities, lack of self esteem, lack of self worth, poor performance in school, poor role models or lack of role models at home or in the community. There is indictment of parents who are just as much in need. The focus on teen pregnancy as one dimensional belies the reality that health, family, work, social and cultural experience affect people's decisions and sexual behavior. The recommendation is for a holistic approach, regardless of race, ethnicity, or socioeconomic background. Adolescents need education and jobs as well as preventive health, body image, and nutrition in conjunction with contraceptives. Where success is defined by motherhood or fatherhood, birth control pills sit in drawers at home. Teenagers need to be convinced that there is some benefit in being connected to mainstream society. Support services need to help teenagers answer the question of what's in it for me? Why? Teenagers need assistance in attaining educational success, job success, the ability to handle anger, and leadership opportunities. A holistic approach is not only realistic but also is the most practical with the longest term benefit. With resources for teen pregnancy superseded by the problems of AIDs and crack gangs, there is a constantly changing political agenda for resource allocation. In fact, teenage pregnancy is reflective of social ills in an urban society simultaneous with drug abuse, school dropouts, juvenile crime and gang activity. The common denominator is that teens all need good educational opportunities, good health, and good housing. Parent involvement is needed, and it is presumptuous to believe that a couple of hours of contact a week can change lives. Parents need respect and understanding for their important role; they need information and a role

  13. Jump dynamics due to jump datum of compressible viscous Navier-Stokes flows in a bounded plane domain

    Science.gov (United States)

    Kweon, Jae Ryong

    2016-09-01

    In this paper, when the initial density has a jump across an interior curve in a bounded domain, we show unique existence, piecewise regularity and jump discontinuity dynamics for the density and the velocity vector governed by the Navier-Stokes equations of compressible viscous barotropic flows. A critical difficulty is in controlling the gradient of the pressure across the jump curve. This is resolved by constructing a vector function associated with the pressure jump value on the convecting curve and extending it to the whole domain.

  14. State policy and teen childbearing: a review of research studies.

    Science.gov (United States)

    Beltz, Martha A; Sacks, Vanessa H; Moore, Kristin A; Terzian, Mary

    2015-02-01

    Teen childbearing is affected by many individual, family, and community factors; however, another potential influence is state policy. Rigorous studies of the relationship between state policy and teen birth rates are few in number but represent a body of knowledge that can inform policy and practice. This article reviews research assessing associations between state-level policies and teen birth rates, focusing on five policy areas: access to family planning, education, sex education, public assistance, and access to abortion services. Overall, several studies have found that measures related to access to and use of family planning services and contraceptives are related to lower state-level teen birth rates. These include adolescent enrollment in clinics, minors' access to contraception, conscience laws, family planning expenditures, and Medicaid waivers. Other studies, although largely cross-sectional analyses, have concluded that policies and practices to expand or improve public education are also associated with lower teen birth rates. These include expenditures on education, teacher-to-student ratios, and graduation requirements. However, the evidence regarding the role of public assistance, abortion access, and sex education policies in reducing teen birth rates is mixed and inconclusive. These conclusions must be viewed as tentative because of the limited number of rigorous studies that examine the relationship between state policy and teen birth rates over time. Many specific policies have only been analyzed by a single study, and few findings are based on recent data. As such, more research is needed to strengthen our understanding of the role of state policies in teen birth rates.

  15. GLBTQ content in comics/graphic novels for teens

    OpenAIRE

    Greyson, Devon

    2007-01-01

    Purpose – This paper aims to provide an historical perspective and current guidance for youth librarians collecting graphic novels for teens. Design/methodology/approach – The paper provides a brief review of the historical issues involved with censorship/intellectual freedom and comics and of current teen-oriented graphic novels with gay, lesbian, bisexual, transgender, queer, and questioning of sexual orientation (GLBTQ) content in Canada and the USA. It also provides a context for negot...

  16. Teen Pregnancy - What You Need to Know PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2011-04-05

    This 60 second PSA is based on the April, 2011 CDC Vital Signs report. Having a child during the teen years comes at a high cost to the young mother, her child, and the community. Get tips to help break the cycle of teen pregnancy.  Created: 4/5/2011 by Centers for Disease Control and Prevention (CDC).   Date Released: 4/5/2011.

  17. Parent-Teen Communication about Sex in Urban Thai Families

    OpenAIRE

    Rhucharoenpornpanich, Orratai; Chamratrithirong, Aphichat; Fongkaew, Warunee; Miller, Brenda A.; Cupp, Pamela K.; Roseti, Michael J.; Byrnes, Hilary F.; Atwood, Katharine; CHOOKHARE, WARUNEE

    2011-01-01

    This study describes sexual communication among Thai parents and their teens and identifies variables related to communication about sex in urban Thai families. Data were derived from 420 families whose teenage children ages 13 – 14 were randomly selected using the probability proportional to size technique. Interviews were conducted with one parent and one teenage child in each family. In-depth interviews were also conducted in 30 parents and teens drawn from the same 420 families. Results s...

  18. Implications of teen birth for overweight and obesity in adulthood.

    Science.gov (United States)

    Chang, Tammy; Choi, HwaJung; Richardson, Caroline R; Davis, Matthew M

    2013-08-01

    The objective of this study was to examine whether teen birth was independently associated with overweight and obesity in a US cohort. We examined whether teen birth is independently associated with overweight and obesity in a multiyear US cohort using the 2001-2010 National Health and Nutrition Examination Survey, a nationally representative cross-sectional survey of the US civilian, noninstitutionalized population. We performed multinomial logistic regression adjusting for survey cohort, age at survey, race, education, and parity. We included women 20-59 years old at the time of survey, with at least 1 live birth, not currently or recently pregnant (unweighted, n = 5220; weighted, n = 48.4 million). Our outcome measure was the effect of teen birth on subsequent overweight and obesity. In bivariate analyses, women with a teen birth were significantly more likely than women without a teen birth to be overweight (relative risk ratios [RRRs], 1.61; 95% confidence interval [CI], 1.37-1.90) or obese (RRR, 1.84; 95% CI, 1.56-2.16) at the time of the survey. In multivariate models, women with a teen birth remained significantly more likely to be overweight (adjusted RRR, 1.33; 95% CI, 1.10-1.62) or obese (adjusted RRR, 1.32; 95% CI, 1.09-1.61) than women without a teen birth. For women in the United States, giving birth as a teen is associated with subsequent overweight/obese status later in life. To inform clinical and policy interventions with the goal to improve the long-term health of teenage mothers, future studies must examine modifiable physiological and sociomedical reasons for early child-bearing and later risk of obesity. Copyright © 2013 Mosby, Inc. All rights reserved.

  19. Jumping and Landing Techniques in Elite Women’s Volleyball

    Science.gov (United States)

    Tillman, Mark D.; Hass, Chris J.; Brunt, Denis; Bennett, Gregg R.

    2004-01-01

    Volleyball has become one of the most widely played participant sports in the world. Participation requires expertise in many physical skills and performance is often dependent on an individual’s ability to jump and land. The incidence of injury in volleyball is similar to the rates reported for sports that are considered more physical contact sports. Though the most common source of injury in volleyball is the jump landing sequence, little research exists regarding the prevalence of jumping and landing techniques. The purpose of this study was to quantify the number of jumps performed by female volleyball players in competitive matches and to determine the relative frequency of different jump-landing techniques. Videotape recordings of two matches among four volleyball teams were analyzed for this study. Each activity was categorized by jump type (offensive spike or defensive block) and phase (jump or landing). Phase was subcategorized by foot use patterns (right, left, or both). Each of the players averaged nearly 22 jump-landings per game. Foot use patterns occurred in unequal amounts (p < 0.001) with over 50% of defensive landings occurring on one foot. Coaches, physical educators, and recreation providers may utilize the findings of this inquiry to help prevent injuries in volleyball. Key Points The incidence of injury in volleyball is nearly equivalent to injury rates reported for ice hockey and soccer. Most injuries in volleyball occur during the jump landing sequence, but few data exist regarding jump landing techniques for elite female players. Our data indicate that the vast majority of jumps utilize two feet, but approximately half of landings occur with only one foot. Coaches, physical educators, and recreation providers may utilize the findings of this inquiry to prevent possible injuries in athletes, students, or those who participate in volleyball for recreational purposes. PMID:24497818

  20. Neuromuscular function during drop jumps in young and elderly males.

    Science.gov (United States)

    Piirainen, Jarmo M; Linnamo, Vesa; Sippola, Niina; Avela, Janne

    2012-12-01

    The Hoffman reflex (H-reflex), indicating alpha-motoneuron pool activity, has been shown to be task - and in resting conditions - age dependent. How aging affects H-reflex activity during explosive movements is not clear at present. The purpose of this study was to examine the effects of aging on H-reflexes during drop jumps, and its possible role in drop jump performance. Ten young (26.8 ± 2.7 years) and twenty elderly (64.2 ± 2.7 years) subjects participated in the study. Maximal drop jump performance and soleus H-reflex response (H/M jump) 20 ms after ground contact were measured in a sledge ergometer. Maximal H-reflex, maximal M-wave, Hmax/Mmax-ratio and H-reflex excitability curves were measured during standing rest. Although in young the H-reflex response (Hmax/Mmax) was 6.5% higher during relaxed standing and 19.7% higher during drop jumps (H jump/M jump) than in the elderly group, these differences were not statistically significant. In drop jumps, the elderly subjects had lower jumping height (30.4%, p push-off force (18.0%, p push-off time (31.0% p push-off force (r = 0.833, p push-off time (r = -0.857, p strategies in drop jumps. However, it does not fully explain age related differences in jumping performance, since age related differences in H-reflex activity were non-significant. Copyright © 2012 Elsevier Ltd. All rights reserved.