Head Start at Ages 3 and 4 versus Head Start Followed by State Pre-K: Which Is More Effective?

Science.gov (United States)

Jenkins, Jade Marcus; Farkas, George; Duncan, Greg J.; Burchinal, Margaret; Vandell, Deborah Lowe

2016-01-01

As policy-makers contemplate expanding preschool opportunities for low-income children, one possibility is to fund two, rather than one year of Head Start for children at ages 3 and 4. Another option is to offer one year of Head Start followed by one year of pre-k. We ask which of these options is more effective. We use data from the Oklahoma…

Spanish Instruction in Head Start and Dual Language Learners' Academic Achievement.

Science.gov (United States)

Miller, Elizabeth B

2017-09-01

Data from the Head Start Impact Study ( N = 1,141) and the Head Start Family and Child Experiences Survey, 2009 Cohort ( N = 825) were used to investigate whether Spanish instruction in Head Start differentially increased Spanish-speaking Dual Language Learners' (DLLs) academic achievement. Although hypothesized that Spanish instruction would be beneficial for DLLs' early literacy and math skills, results from residualized growth models showed there were no such positive associations. Somewhat surprisingly, DLL children instructed in Spanish had higher English receptive vocabulary skills at the end of the Head Start year than those not instructed, with children randomly assigned to Head Start and instructed in Spanish having the highest scores. Policy implications for Head Start-eligible Spanish-speaking DLLs are discussed.

The Role of Classroom Quality in Explaining Head Start Impacts

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Connors, Maia C.; Friedman-Krauss, Allison H.; Morris, Pamela A.; Page, Lindsay C.; Feller, Avi

2014-01-01

This study seeks to answer the following question: Are impacts on Head Start classroom quality associated with impacts of Head Start on children's learning and development? This study employs a variety of descriptive and quasi-experimental methods to explore the role of classroom quality as a mediator or mechanism of Head Start impacts. This…

Enhancing Early Childhood Outcomes: Connecting Child Welfare and Head Start

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McCrae, Julie S.; Brown, Samantha M.; Yang, Jessica; Groneman, Sheila

2016-01-01

Head Start is a preschool program for families with low incomes and nearly 85% of child welfare-involved families are low-income, yet little is known about Head Start and child welfare collaboration. This study uses data from 28 Head Start directors to describe collaboration facilitators and barriers, and collaborative mechanisms in place. The…

76 FR 70009 - Head Start Program

Science.gov (United States)

2011-11-09

... importance of the early years of a child's growth and development. On December 12, 2007, the Improving Head... education, serving nearly one million of our nation's most vulnerable young children and their families. It... Administration for Children and Families 45 CFR Part 1307 Head Start Program; Final Rule #0;#0;Federal Register...

Head Start, 4 years After Completing the Program

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Kim, Young-Joo

2013-01-01

This paper studies the effect of the Head Start program on children's achievements in reading and math tests during their first 4 years of schooling after completing the program. Using nationally representative data from the Early Childhood Longitudinal Study, I found large measurement error in the parental reports of Head Start attendance, which…

Head Start Impact Study. Final Report. Executive Summary

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Puma, Michael; Bell, Stephen; Cook, Ronna; Heid, Camilla; Shapiro, Gary; Broene, Pam; Jenkins, Frank; Fletcher, Philip; Quinn, Liz; Friedman, Janet; Ciarico, Janet; Rohacek, Monica; Adams, Gina; Spier, Elizabeth

2010-01-01

This report summarizes the findings from a study on the impacts of Head Start on children and families during the children's preschool, kindergarten, and 1st grade years. Its study goals were to: (1) Determine the impact of Head Start on children's school readiness, and on parental practices that support children's development; and to (2)…

Head Start Center Design Guide.

Science.gov (United States)

Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

This guide contains suggested criteria for planning, designing, and renovating Head Start centers so that they are safe, child-oriented, developmentally appropriate, beautiful, environmentally sensitive, and functional. The content is based on the U.S. General Services Administration's Child Care Center Design Guide, PBS-P140, which was intended…

Increasing Culturally Diverse Meals in Head Start Using a Collaborative Approach: Lessons Learned for School Food Service Modifications

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Hoffman, Jessica A.; Agrawal, Tara; Thompson, Douglas; Ferguson, Tyler; Grinder, AnnMarie; Carter, Sonia; Healey, Christine; Bhaumik, Urmi; Castaneda-Sceppa, Carmen

2012-01-01

Head Start's performance standards require that the nutrition programs "serve a variety of foods which consider cultural and ethnic preferences and which broaden the child's food experience" (Head Start Program Performance Standards and Other Regulations, 2006). In this study, food service modifications were made via a participatory…

Quantifying Variation in Head Start Effects on Young Children's Cognitive and Socio-Emotional Skills Using Data from the National Head Start Impact Study

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Bloom, Howard S.; Weiland, Christina

2015-01-01

This paper uses data from the Head Start Impact Study (HSIS), a nationally representative multisite randomized trial, to quantify variation in effects of Head Start during 2002-2003 on children's cognitive and socio-emotional outcomes relative to the effects of other local alternatives, including parent care. We find that (1) treatment and control…

The Impact of Head Start on Children, Families and Communities. Final Report of the Head Start Evaluation, Synthesis and Utilization Project. Executive Summary.

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McKey, Ruth Hubbell; And Others

This report summarizes the results of a study on the impact of Head Start on children's cognitive and socioemotional development, on child health and health institutions in the community, on enrollees' families, and on communities where Head Start programs operate. After discussing the background and methodology of the study, the report concludes…

Planning and Reviewing for Success. Training Guides for the Head Start Learning Community.

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Aspen Systems Corp., Rockville, MD.

This guide offers Head Start staff a blueprint for developing the skills and methods necessary for a Head Start program's planning and review process. The guide stresses the need for Head Start administrative and managerial leadership to maintain a holistic, integrated approach; use the strength and resources of Head Start team members; identify…

Caregivers' attitudes regarding portion sizes served to children at Head Start

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Head Start caregivers are responsible for educating and feeding preschoolers enrolled in the Head Start program. Amongst pre-school aged children, portion size served is positively associated with intake of those foods. Researchers conducted eight focus groups with Hispanic and African American Head...

School Readiness in Children Living in Non-Parental Care: Impacts of Head Start

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Lipscomb, Shannon T.; Pratt, Megan E.; Schmitt, Sara A.; Pears, Katherine C.; Kim, Hyoun K.

2013-01-01

The current study examines the effects of Head Start on the development of school readiness outcomes for children living in non-parental care. Data were obtained from the Head Start Impact Study, a randomized controlled trial of Head Start conducted with a nationally representative sample of Head Start programs and families. The sample included…

Head Start's Impact Is Contingent on Alternative Type of Care in Comparison Group

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Zhai, Fuhua; Brooks-Gunn, Jeanne; Waldfogel, Jane

2014-01-01

Using data ("n" = 3,790 with 2,119 in the 3-year-old cohort and 1,671 in the 4-year-old cohort) from 353 Head Start centers in the Head Start Impact Study, the only large-scale randomized experiment in Head Start history, this article examined the impact of Head Start on children's cognitive and parent-reported social-behavioral outcomes…

Caregivers' attitudes regarding portion size served to Head Start children

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The purpose of this study was to identify caregivers' attitudes regarding amounts and types of foods served to Head Start preschoolers using qualitative methods. Researchers conducted 8 focus groups (4 African American; 4 Hispanic) with 33 African American and 29 Hispanic Head Start caregivers. Mode...

Does Head Start differentially benefit children with risks targeted by the program's service model?

Science.gov (United States)

Miller, Elizabeth B; Farkas, George; Duncan, Greg J

Data from the Head Start Impact Study ( N = 3540) were used to test for differential benefits of Head Start after one program year and after kindergarten on pre-academic and behavior outcomes for children at risk in the domains targeted by the program's comprehensive services. Although random assignment to Head Start produced positive treatment main effects on children's pre-academic skills and behavior problems, residualized growth models showed that random assignment to Head Start did not differentially benefit the pre-academic skills of children with risk factors targeted by the Head Start service model. The models showed detrimental impacts of Head Start for maternal-reported behavior problems of high-risk children, but slightly more positive impacts for teacher-reported behavior. Policy implications for Head Start are discussed.

Parental Book Reading and Social-Emotional Outcomes for Head Start Children in Foster Care.

Science.gov (United States)

Lee, Kyunghee; Lee, Jung-Sook

2016-01-01

This study examines the associations between parental book reading and social-emotional outcomes for Head Start children in foster care. Despite no main Head Start impact on parental book reading, subgroup effects were found. Foster parents in Head Start provided more book reading for children with disabilities but less for children with low preacademic scores. Head Start enhanced social-emotional outcomes for children in foster care. The positive impacts of Head Start on children's social-emotional outcomes were greater when parents read books frequently. Head Start should include more foster families and provided parenting skills to enhance social-emotional outcomes for children in foster care.

Early Head Start Participants, Programs, Families, and Staff in 2014

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Mohan, Anitha; Walker, Christina

2016-01-01

In 1994, the federal Early Head Start (EHS) program was created to address the comprehensive needs of low-income pregnant women and children under age 3. EHS was launched almost 30 years after Head Start was established in 1965 to serve low-income 3- and 4-year-old children and their families with comprehensive early education and support…

Head Start Teacher Well-Being: Implications for Policy and Practice

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Bullough, Robert V., Jr.; Hall-Kenyon, Kendra M.; MacKay, Kathryn Lake

2012-01-01

Surprisingly little is known about Head Start teachers; who teaches, why they teach, and how they think and feel about their work. To begin to address these issues, a survey was developed and distributed to Head Start teachers, assistant teachers, and aides in one three-county program to examine their motivation and well-being. Follow-up…

Renewing Head Start's Promise: Invest in What Works for Disadvantaged Preschoolers

Science.gov (United States)

Mead, Sara

2014-01-01

Since Head Start's last reauthorization in 2007, the Department of Health and Human Services, which oversees Head Start, has implemented significant reforms that are improving the program. In "Renewing Head Start's Promise: Invest in What Works for Disadvantaged Preschoolers," Sara Mead offers several recommendations to enable…

Lessons in a Box Make a Difference for Head Start Youth

Science.gov (United States)

Kunkel, Kelly K.; Hurtado, Ghaffar A.; Conrad, Stephanie; Routh, Brianna; Joeng, Ju Ri; Harrison, Megan

2014-01-01

This article examines the health education implications of targeted nutrition lesson plans at Head Start programs in south central Minnesota. The Head Start program in Mankato and the University of Minnesota Extension collaborated to deliver and evaluate a nutrition education program directed at preschool children and their families. Nine lesson…

Head Start Impact on Social-Emotional Outcomes for Children with Disabilities

Science.gov (United States)

Lee, Kyunghee; Calkins, Andrea; Shin, Tae Seob

2016-01-01

Objective: Using the Head Start Impact Study data, this study examines Head Start's impacts on social-emotional outcomes for children with disabilities. Method: Among 4,442 children, 570 children were reported to have disabilities. Ordinary least squares regression was used to determine whether the number of disabilities, having an individualized…

Does Head Start differentially benefit children with risks targeted by the program’s service model?☆

Science.gov (United States)

Miller, Elizabeth B.; Farkas, George; Duncan, Greg J.

2015-01-01

Data from the Head Start Impact Study (N = 3540) were used to test for differential benefits of Head Start after one program year and after kindergarten on pre-academic and behavior outcomes for children at risk in the domains targeted by the program’s comprehensive services. Although random assignment to Head Start produced positive treatment main effects on children’s pre-academic skills and behavior problems, residualized growth models showed that random assignment to Head Start did not differentially benefit the pre-academic skills of children with risk factors targeted by the Head Start service model. The models showed detrimental impacts of Head Start for maternal-reported behavior problems of high-risk children, but slightly more positive impacts for teacher-reported behavior. Policy implications for Head Start are discussed. PMID:26379369

Competition or Collaboration? Head Start Enrollment during the Rapid Expansion of State Pre-Kindergarten

Science.gov (United States)

Bassok, Daphna

2012-01-01

Over the past decade states have surpassed the federal Head Start program as the primary public funder of preschool slots. This paper investigates trends in Head Start enrollment in the context of increased state investment in early childhood. Using national, longitudinal data I find no evidence Head Start programs in states with expanding state…

Changes in parents' spanking and reading as mechanisms for Head Start impacts on children.

Science.gov (United States)

Gershoff, Elizabeth T; Ansari, Arya; Purtell, Kelly M; Sexton, Holly R

2016-06-01

This study examined whether Head Start, the nation's main two-generation program for low-income families, benefits children in part through positive changes in parents' use of spanking and reading to children. Data were drawn from the 3-year-old cohort of the national evaluation of the Head Start program known as the Head Start Impact Study (N = 2,063). Results indicated that Head Start had small, indirect effects on children's spelling ability at Age 4 and their aggression at Age 4 through an increase in parents' reading to their children. Taken together, the results suggest that parents play a role in sustaining positive benefits of the Head Start program for children's behavior and literacy skills, one that could be enhanced with a greater emphasis on parent involvement and education. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

An Overview of Head Start Program Studies

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Hines, Jeanne Morris

2017-01-01

Johnson's "War on Poverty" administrative team campaigned for committee members to join the War on Poverty efforts to create and develop programs for children born into poverty (Zigler, 2003). Poverty based programs, such as the Head Start program, continue to put into place proactive measures to increase preschooler's cognitive…

Addressing Tooth Decay in Head Start Children

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Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

2012-01-01

Tooth decay is the most prevalent chronic disease of childhood. Oral health education and dental services are crucial to reducing the number of children afflicted with dental cavities. Due to limited access to preventative care, Head Start children are particularly vulnerable to tooth decay. This article outlines practical implications of a…

Oral health of early head start children: a qualitative study of staff, parents, and pregnant women.

Science.gov (United States)

Mofidi, Mahyar; Zeldin, Leslie P; Rozier, R Gary

2009-02-01

We explored the oral health knowledge, attitudes, and activities of Early Head Start (EHS) staff members, parents, and pregnant women, along with their suggestions related to future oral health educational interventions targeting EHS children. Nine focus groups were conducted with EHS staff, parents, and pregnant women. Audiotapes of sessions were transcribed and entered into ATLAS.ti 5.0 for coding and analysis. Attitudes about the importance of children's oral health among parents and pregnant women were mixed. Staff members voiced responsibility for children's oral health but frustration in their inability to communicate effectively with parents. Parents in turn perceived staff criticism regarding how they cared for their children's oral health. Gaps were noted in the oral health activities of EHS programs. Participants expressed confusion regarding the application of Head Start oral health performance standards to EHS. The need for culturally sensitive, hands-on oral health education was highlighted. Tailored, theory-based interventions are needed to improve communication between EHS staff and families. Clear policies on the application of Head Start oral health performance standards to EHS are warranted. Educational activities should address the needs and suggestions of EHS participants.

Western Pond Turtle Head-starting and Reintroduction; 2004-2005 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Van Leuven, Susan; Allen, Harriet; Slavin, Kate (Washington Department of Fish and Wildlife, Wildlife Management Program, Olympia, WA)

2005-09-01

This report covers the results of the western pond turtle head-starting and reintroduction project for the period of October 2004-September 2005. Wild hatchling western pond turtles from the Columbia River Gorge were reared at the Woodland Park and Oregon Zoos in 2004 and 2005 as part of the recovery effort for this Washington State endangered species. The objective of the program is to reduce losses to introduced predators like bullfrogs and largemouth bass by raising the hatchlings to a size where they are too large to be eaten by most of these predators. Thirty-five turtles were placed at the Woodland Park Zoo and 53 at the Oregon Zoo. Of these, 77 head-started juvenile turtles were released at three sites in the Columbia Gorge in 2005. Four were held back to attain more growth in captivity. Eleven were released at the Klickitat ponds, 22 at the Klickitat lake, 39 at the Skamania site, and 5 at Pierce National Wildlife Refuge (NWR). This brought the total number of head-start turtles released since 1991 to 257 for the Klickitat ponds, 136 for the Klickitat lake, 206 for the Skamania pond complex, and 255 at Pierce NWR. In 2005, 34 females from the two Columbia Gorge populations were equipped with transmitters and monitored for nesting activity. Twenty-four nests were located and protected; these produced 90 hatchlings. The hatchlings were collected in September and transported to the Oregon and Woodland Park zoos for rearing in the head-start program. During the 2005 field season trapping effort, 486 western pond turtles were captured in the Columbia Gorge, including 430 previously head-started turtles. These recaptures, together with confirmed nesting by head-start females and visual resightings, indicate the program is succeeding in boosting juvenile recruitment to increase the populations. Records were also collected on 216 individual painted turtles captured in 2005 during trapping efforts at Pierce NWR, to gather baseline information on this native

Western Pond Turtle Head-starting and Reintroduction, 2005-2006 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Van Leuven, Susan; Allen, Harriet; Slavens, Kate (Washington Department of Fish and Wildlife, Wildlife Management Program, Olympia, WA)

2006-11-01

This report covers the results of the western pond turtle head-starting and reintroduction project for the period of October 2005-September 2006. Wild hatchling western pond turtles from the Columbia River Gorge were reared at the Woodland Park and Oregon zoos in 2005 and 2006 as part of the recovery effort for this Washington State endangered species. The objective of the program is to reduce losses to introduced predators like bullfrogs and largemouth bass by raising the hatchlings to a size where they are too large to be eaten by most of these predators. Twenty-six turtles were placed at the Woodland Park Zoo and 62 at the Oregon Zoo in fall 2005. These turtles joined two that were held back from release in summer 2005 due to their small size. All 90 juvenile turtles were released at three sites in the Columbia Gorge in 2006. Twenty-eight juvenile turtles were released at the Klickitat ponds, 22 at the Klickitat lake, 21 at the Skamania site, and 19 at Pierce National Wildlife Refuge (NWR). This brought the total number of head-start turtles released since 1991 to 944; 285 for the Klickitat ponds, 158 for the Klickitat lake, 227 for the Skamania pond complex, and 274 at Pierce NWR. In 2006, 20 females from the Klickitat population were equipped with transmitters and monitored for nesting activity. Fifteen nests were located and protected; these produced 55 hatchlings. The hatchlings were collected in September and transported to the Oregon and Woodland Park zoos for rearing in the head-start program. One wild hatchling captured in spring 2006 was placed in the head-start program to attain more growth in captivity. During the 2006 field season trapping effort, 414 western pond turtles were captured in the Columbia Gorge, including 374 previously head-started turtles. These recaptures, together with confirmed nesting by head-start females and visual resightings, indicate the program is succeeding in boosting juvenile recruitment to increase the populations

Parent Involvement in Head Start and Children's Development: Indirect Effects Through Parenting.

Science.gov (United States)

Ansari, Arya; Gershoff, Elizabeth

2016-04-01

The authors examined the extent to which parent involvement in Head Start programs predicted changes in both parent and child outcomes over time, using a nationally representative sample of 1,020 three-year-old children over 3 waves of the Family and Child Experiences Survey. Center policies that promote involvement predicted greater parent involvement, and parents who were more involved in Head Start centers demonstrated increased cognitive stimulation and decreased spanking and controlling behaviors. In turn, these changes in parenting behaviors were associated with gains in children's academic and behavioral skills. These findings suggest that Head Start programs should do even more to facilitate parent involvement because it can serve as an important means for promoting both parent and child outcomes.

Peer Effects on Head Start Children’s Preschool Competency

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DeLay, Dawn; Hanish, Laura D.; Martin, Carol Lynn; Fabes, Richard A.

2015-01-01

The goals of the present study were to investigate whether young children attending Head Start (N=292; Mage=4.3 years) selected peers based on their preschool competency and whether children’s levels of preschool competency were influenced by their peers’ levels of preschool competency. Children’s peer interaction partners were intensively observed several times a week over one academic year. Social network analyses revealed that children selected peer interaction partners with similar levels of preschool competency and were influenced over time by their partners’ levels of preschool competency. These effects held even after controlling for several child (e.g., sex and language) and family factors (e.g., financial strain and parent education). Implications for promoting preschool competency among Head Start children are discussed. PMID:26479545

Chronic Homelessness, Head Start, and Changing Federal Policies: Teaching and Learning at Hawthorne House

Science.gov (United States)

Bullough, Robert V., Jr.; Hall-Kenyon, Kendra M.

2015-01-01

Federal policy changes for Head Start (HS) elevate the importance of measured academic performance over other traditional program aims, particularly those associated with the social-emotional development of children. Concerned about the possible effects of these changes on children, based on observations and interviews, detailed portraits of…

Arsenic Removal from Drinking Water by Adsorptive Media, U.S. EPA Demonstration Project at LEADS Head Start Building in Buckeye Lake, OH - Final Performance Evaluation Report

Science.gov (United States)

This report documents the activities performed and the results obtained for the arsenic removal treatment technology demonstration project at Licking Economic Action Development Study (LEADS) Head Start School in Buckeye Lake, Ohio. The objectives of the project were to evaluate...

Promoting School Success: Developing Social Skills and Early Literacy in Head Start Classrooms

Science.gov (United States)

Gunn, Barbara; Feil, Ed; Seeley, John; Severson, Herb; Walker, Hill M.

2006-01-01

This article reports the results of a pilot intervention to improve the social skills and literacy preparation of behaviorally at-risk Head Start children. Teachers in eight Head Start classrooms in two Oregon communities participated during the 2002-03 school year. Children in eight classrooms were screened and identified for participation using…

Arizona Head Start for Homeless Children and Families Project. 1994-95 Evaluation Report.

Science.gov (United States)

Mulholland, Lori; Greene, Andrea

Homeless families with children comprise the fastest growing segment of the United States homeless population. This study evaluated Year 1 of the Arizona Head Start for Homeless Children and Families Project, designed to meet educational and social needs of homeless children and families, and to assist Head Start agencies in developing effective…

Arizona Head Start for Homeless Children and Families Project. 1995-96 Evaluation Report.

Science.gov (United States)

Mulholland, Lori

Homeless families with children constitute the fastest growing segment of the United States homeless population. This study evaluated Year 2 of the Arizona Head Start for Homeless Children and Families Project, designed to meet educational and social needs of homeless children and families, and to assist Head Start agencies in developing effective…

Moneyball for Head Start: Using Data, Evidence, and Evaluation to Improve Outcomes for Children and Families

Science.gov (United States)

Mead, Sara; Mitchel, Ashley LiBetti

2016-01-01

Head Start is a valuable federal program that improves the lives of our nation's most vulnerable children and their families. Research shows that Head Start programs improve children's learning at school entry and have a positive impact on long-term life outcomes. Research also suggests that Head Start could have a stronger impact on children's…

Steps to Successful Professional Development in Head Start

Science.gov (United States)

Trivette, Carol M.; Raab, Melinda; Dunst, Carl J.

2012-01-01

This article discusses the implications of utilizing coaching-mentoring strategies with Head Start teachers identified from the results of a study which used an evidence-based approach to professional development. Early childhood and coaching practices that formed the basis of the study are explained. Implications from the study results regarding…

Head Start, Pre-Kindergarten, and Academic School Readiness: A Comparison Among Regions in the U.S

Science.gov (United States)

Zhai, Fuhua; Waldfogel, Jane; Brooks-Gunn, Jeanne

2013-01-01

Child care programs (including Head Start, pre-Kindergarten [pre-K], and other center-based care) can differ, with patterns of use based on their location. Yet little research has examined how Head Start and pre-K programs affect children’s academic school readiness, including vocabulary and reading skills at school entry, in the South as compared to other regions. To examine this further, secondary data (n = 2,803) collected in the Fragile Families and Child Wellbeing Study were examined. Overall findings suggest, regardless of region, that Head Start and pre-K participants had higher academic skills at school entry than their counterparts. In addition, when Head Start was compared to other center-based care and pre-K was compared to other care arrangements, both had larger effects on improving academic skills in the South than in other regions. These findings imply that Head Start and pre-K programs should target children who otherwise would receive non-parental non-center-based care. Future research should focus on why the effects of Head Start and pre-K vary between the South and other regions. PMID:23729917

Head Start and Urban Children’s School Readiness: A Birth Cohort Study in 18 Cities

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Zhai, Fuhua; Brooks-Gunn, Jeanne; Waldfogel, Jane

2011-01-01

We used longitudinal data from a birth cohort study, the Fragile Families and Child Wellbeing Study, to investigate the links between Head Start and school readiness in a large and diverse sample of urban children at age 5 (N = 2,803; 18 cities). We found that Head Start attendance was associated with enhanced cognitive ability and social competence and reduced attention problems but not reduced internalizing or externalizing behavior problems. These findings were robust to model specifications (including models with city-fixed effects and propensity-scoring matching). Furthermore, the effects of Head Start varied by the reference group. Head Start was associated with improved cognitive development when compared with parental care or other nonparental care, as well as improved social competence (compared with parental care) and reduced attention problems (compared with other nonparental care). In contrast, compared with attendance at pre-kindergarten or other center-based care, Head Start attendance was not associated with cognitive gains but with improved social competence and reduced attention and externalizing behavior problems (compared with attendance at other center-based care). These associations were not moderated by child gender or race/ethnicity. PMID:21244155

Oral Health Knowledge, Past Oral Health Behaviors, and Barriers to Preventive Oral Care of Head Start Parents

Science.gov (United States)

Knowlden, Adam P.; Hill, Lawrence F.; Alles-White, Monica L.; Cottrell, Randall R.

2012-01-01

Tooth decay remains the most common chronic disease of childhood. The CincySmiles Foundation (CSF) developed an instrument to evaluate Head Start parents' knowledge of oral health care practices and to identify barriers Head Start parents face when seeking dental treatment for their children. Data from Head Start parents (n = 675) across 3…

Effectiveness of an oral health program in improving the knowledge and competencies of head start staff.

Science.gov (United States)

Chinn, Courtney Hugh

2011-01-01

Head Start and Early Head Start (HS/EHS) programs have partnered with the American Academy of Pediatric Dentistry to promote oral health and increase access to dental homes. Preparing HS/EHS staff for issues related to pediatric oral health promises to improve effectiveness of this collaboration. This paper's purpose was to describe the Columbia Head Start Oral Health Program (C-HSOHP) and changes in HS/EHS staff pediatric oral health knowledge and competencies after participating in C-HSOHP. Four HS/EHS grantees in New York City engaged in the 2008-09 C-HSOHP. A convenience sample of 61 staff completed pre- and postself assessments of knowledge and competencies. Significant paired mean improvements were found for staff-reported level of preparation to explain dental issues during pregnancy, the tooth decay process, and preparing parents for their child's first dental visit. Significant improvements were found in staff confidence in teaching parents about children's oral health issues, referring for pediatric dental services, and talking to a dentist about a concern. The Columbia Head Start Oral Health Program was effective in improving Head Start/Early Head Start staff self-confidence and self-perceived preparedness in teaching parents about oral health, applying oral health knowledge to HS/EHS programs, communicating with dental professionals, and improving access to pediatric dental services.

Parent Involvement in Head Start Programs: The Role of Parent, Teacher and Classroom Characteristics

Science.gov (United States)

Castro, D.C.; Bryant, D.M.; Peisner-Feinberg, E.S.; Skinner, M.L.

2004-01-01

The purposes of this study were to determine the extent and types of parent involvement in Head Start programs, and to examine the relations between parent participation and family, teacher and classroom characteristics. Parents (n = 1131) and teachers (n = 59) from four Head Start programs participated. Data were gathered through volunteer logs,…

Behavioral and Psychosocial Characteristics Among Head Start Childcare Providers.

Science.gov (United States)

Ling, Jiying

2017-01-01

The aim of the study was twofold: (a) describe behavioral and psychosocial characteristics of Head Start childcare providers including technology use, physical activity, nutrition, depression, and quality of life and (b) examine associations among these characteristics. Using a cross-sectional design, a nonrandom sample of 80 Head Start childcare providers completed an online survey via SurveyMonkey. About 80.1% were overweight or obese. Nearly all had a computer or smartphone. About 55% met the national physical activity recommendation of 150 min/week. Approximately 56.2% did not know the recommended daily servings of fruits and vegetables, and 26.3% had ≥3 servings of vegetables per day. About 38.8% had major depression or dysthymia, and 31.3% had depressive symptoms. The top two perceived health needs were weight loss and stress management. Providing a health promotion and stress management program to childcare providers may benefit both providers and children, considering the strong influence of teachers on children.

Head Start Participants, Programs, Families and Staff in 2012

Science.gov (United States)

Schmit, Stephanie

2013-01-01

Since 1965, the Head Start program has served low-income 3- and 4-year-old children and their families with comprehensive early education and support services. Programs provide services focused on the "whole child," including early education addressing cognitive, developmental, and socio-emotional needs; medical and dental screenings and…

Head Start Participants, Programs, Families, and Staff in 2014

Science.gov (United States)

Mohan, Anitha; Walker, Christina

2016-01-01

Since 1965, the Head Start program has served low-income 3- and 4-year-old children and their families with comprehensive early education and support services. Programs provide services focused on the "whole child," including early education addressing cognitive, developmental, and socio-emotional needs; medical and dental screenings and…

The use of child-centered play therapy and filial therapy with Head Start families: a brief report.

Science.gov (United States)

Johnson, L; Bruhn, R; Winek, J; Krepps, J; Wiley, K

1999-04-01

Play therapy and filial therapy show promise as effective ways to provide direct services to Head Start, addressing the needs of the children, the families, and the Head Start teachers and staff. This paper examines the utility of play and filial therapies for the Head Start population, presents a systemic explanation for the benefit of filial therapy, and provides a case example for illustration.

Delayed Instructional Control of Head Start Children's Free Play.

Science.gov (United States)

Pierce, Charles H.; Risley, Todd R.

The free play of 5 black preschool Head Start children was observed. The variables manipulated in the study were delayed instructions and reinforcement for play with selected toys, and specific versus general instructions; the correspondence between the adult's instructions and reinforcement to the children's play was assessed. The data indicated…

Classroom Writing Environments and Children's Early Writing Skills: An Observational Study in Head Start Classrooms

Science.gov (United States)

Zhang, Chenyi; Hur, Jinhee; Diamond, Karen E.; Powell, Douglas

2015-01-01

This study examined the classroom writing environment in 31 Head Start classrooms, and explored the relations between the writing environment, children's (N = 262) name-writing, and children's letter knowledge using pathway analysis. Our analyses showed that Head Start classrooms provided opportunities (i.e., writing materials and teachers'…

A Mental Health Consultation Program for Project Head Start.

Science.gov (United States)

Kawin, Marjorie R.

The Psychological Center provided a family oriented mental health consultation service to 17 delegate agencies who had contracts with Head Start programs in 1966-67. This paper presents an overview of the services which an interdisciplinary staff of 52 professionals provided to 6,780 families and 1,500 agency staff members. Gerald Caplan's (1964)…

The Impact of Parent Involvement in Head Start on Parents and Children. Final Report [and] Executive Summary.

Science.gov (United States)

Parker, Faith Lamb; Piotrkowski, Chaya S.; Kessler-Sklar, Susan; Baker, Amy J. L.; Peay, Lenore; Clark, Beryl

From its inception, Head Start's legislative mandate called for "maximum feasible participation" of parents in all programmatic efforts and policy decisions. Nevertheless, there has been little research done on the benefits of Head Start to parents and on the role of parents as mediators of child and family outcomes. The Head Start…

Testing maternal depression and attachment style as moderators of Early Head Start's effects on parenting.

Science.gov (United States)

Berlin, Lisa J; Whiteside-Mansell, Leanne; Roggman, Lori A; Green, Beth L; Robinson, JoAnn; Spieker, Susan

2011-01-01

This study examined maternal depression, attachment avoidance, and attachment anxiety as moderators of Early Head Start's effects on four parenting outcomes assessed at age three. Participants (N = 947) were drawn from six sites of the Early Head Start National Research and Evaluation Project, a multi-site randomized trial. Findings suggest more positive program effects for mothers with less initial attachment avoidance or attachment anxiety. First, baseline attachment avoidance moderated Early Head Start program effects on observed maternal supportiveness, such that program mothers with lower baseline attachment avoidance were rated as more supportive of their three-year-olds than program mothers with higher baseline attachment avoidance. Second, program effects on spanking varied depending on mothers' baseline attachment anxiety.

The sleeping patterns of Head Start children and the influence on developmental outcomes.

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Schlieber, M; Han, J

2018-05-01

Sleep has a significant influence on children's development. The objective of this study was to investigate Head Start children's sleeping patterns and the impact on cognitive and behavioural outcomes. Using the 2009 cohort of the Head Start Family and Child Experiences Survey (N = 2,868), information on sleeping patterns was assessed through parent interviews. Cognitive outcomes were assessed using direct assessments (Peabody Picture Vocabulary Test-IV, the Expressive One-Word Picture Vocabulary Test, and Subtests of the Woodcock-Johnson III) in addition to teacher report. Behavioural outcomes were assessed through parent and teacher reports. A multiple regression analysis was performed for each outcome variable. Descriptive findings showed that 89% of children had a regular bedtime at least 4 days per week and that the average amount of sleep per night was 10.41 hr. White mothers were more likely than other racial groups to adhere to a consistent bedtime, and maternal employment predicted less hour of sleep per night. Multiple regression analyses revealed that disrupted sleep had a negative influence on cognitive outcomes, especially in areas of mathematical problem solving, receptive language, teacher-reported literacy behaviours, and approaches to learning. Disrupted sleep was associated with the risk of misbehaviour by increasing teacher and parent ratings on aggressive behaviours, hyperactivity, and withdrawing in addition to decreased scores on overall social skills. Having an inconsistent bedtime negatively predicted expressive vocabulary and teacher-reported literacy behaviours. The findings of this study support the influential role of sleep on children's development. Sleeping through the night and having a consistent bedtime were found to be predictive of many areas of cognitive and behavioural development. Head Start staff can provide the supports to increase parental knowledge on appropriate child sleep practices. © 2017 John Wiley & Sons Ltd.

Understanding Head Start Children's Problem Behaviors in the Context of Arrest or Incarceration of Household Members

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Ziv, Yair; Alva, Soumya; Zill, Nicholas

2010-01-01

Using data from the nationally representative Head Start Family and Child Experiences Survey (FACES), the relationships between living in a household where a household member had been arrested or incarcerated and conduct problems of preschool children enrolled in Head Start were examined. Children who lived in such households showed more…

Evaluating the Validity of Classroom Observations in the Head Start Designation Renewal System

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Mashburn, Andrew J.

2017-01-01

Classroom observations are increasingly common in education policies as a means to assess the quality of teachers and/or education programs for purposes of making high-stakes decisions. This article considers one policy, the Head Start Designation Renewal System (DRS), which involves classroom observations to assess the quality of Head Start…

Head Start.

Science.gov (United States)

Greenman, Geri

2000-01-01

Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

Parents' Role in the Early Head Start Children's Language Development

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Griswold, Cecelia Smalls

2014-01-01

The development of language during a child's early years has been linked to parental involvement. While Early Head Start (EHS) researchers have theorized that parental involvement is an important factor in language development, there has been little research on how parents view their roles in the language development process. The purpose of this…

A Head Start on Concussion Recovery | NIH MedlinePlus the Magazine

Science.gov (United States)

... and Concussions Follow us A Head Start on Concussion Recovery Life lessons after three pediatric concussions "It would have been easier if he had ... Michelle Marchionni says about her son Sam's first concussion. In the fall of 2012, 8-year-old ...

Absenteeism in Head Start and Children's Academic Learning

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Ansari, Arya; Purtell, Kelly

2016-01-01

Using nationally representative data from the Family and Child Experiences Survey 2009 Cohort (n = 2,842), this study examined the implications of 3- and 4-year-old's absences from Head Start for their early academic learning. The findings from this study revealed that children who missed more days of school, and especially those who were…

One Third More: Maine Head Start Expansion with State Funds.

Science.gov (United States)

Weil, Jane

The expansion of Project Head Start in Maine to the point of serving nearly 25 percent of eligible children is detailed in this report. Section I describes the expansion and some of its benefits, such as equalization of services across county boundaries and the establishment of a uniform unit cost-per-child for use in appropriating state funds.…

Promoting academic and social-emotional school readiness: the head start REDI program.

Science.gov (United States)

Bierman, Karen L; Domitrovich, Celene E; Nix, Robert L; Gest, Scott D; Welsh, Janet A; Greenberg, Mark T; Blair, Clancy; Nelson, Keith E; Gill, Sukhdeep

2008-01-01

Forty-four Head Start classrooms were randomly assigned to enriched intervention (Head Start REDI-Research-based, Developmentally Informed) or "usual practice" conditions. The intervention involved brief lessons, "hands-on" extension activities, and specific teaching strategies linked empirically with the promotion of: (a) social-emotional competencies and (b) language development and emergent literacy skills. Take-home materials were provided to parents to enhance skill development at home. Multimethod assessments of three hundred and fifty-six 4-year-old children tracked their progress over the course of the 1-year program. Results revealed significant differences favoring children in the enriched intervention classrooms on measures of vocabulary, emergent literacy, emotional understanding, social problem solving, social behavior, and learning engagement. Implications are discussed for developmental models of school readiness and for early educational programs and policies.

A Pilot Study of a Pictorial Bilingual Nutrition Education Game to Improve the Consumption of Healthful Foods in a Head Start Population

Directory of Open Access Journals (Sweden)

Veronica Piziak

2012-04-01

Full Text Available The prevalence of early childhood obesity has increased dramatically particularly among the Mexican American population. Obesity leads to earlier onset of related diseases such as type 2 diabetes. The Head Start population of Texas is largely Mexican American. Dietary intake in this population demonstrated a diet very low in fiber, high in salt, and containing excessive calories with a low intake of fruit and vegetables. This study was performed in a Texas Head Start population to evaluate a bilingual pictorial nutrition education game. Acceptance of the bilingual concept and the game had been previously studied in a Head Start population in five Texas counties. The effectiveness in producing a change in eating habits was studied as a pilot project 413 children and their parents at the Bastrop County Head Start. Parents were asked to supply data about at home food frequency at the beginning and the end of the school year and the results compared. The parents were given a demonstration of the educational objectives and the students played the game throughout the year. By the end of the school year there was a statistically significant increase in the vegetables offered to this population both during the week at home (p = 0.009 and on the weekends (p = 0.02.

A pilot study of a pictorial bilingual nutrition education game to improve the consumption of healthful foods in a head start population.

Science.gov (United States)

Piziak, Veronica

2012-04-01

The prevalence of early childhood obesity has increased dramatically particularly among the Mexican American population. Obesity leads to earlier onset of related diseases such as type 2 diabetes. The Head Start population of Texas is largely Mexican American. Dietary intake in this population demonstrated a diet very low in fiber, high in salt, and containing excessive calories with a low intake of fruit and vegetables. This study was performed in a Texas Head Start population to evaluate a bilingual pictorial nutrition education game. Acceptance of the bilingual concept and the game had been previously studied in a Head Start population in five Texas counties. The effectiveness in producing a change in eating habits was studied as a pilot project 413 children and their parents at the Bastrop County Head Start. Parents were asked to supply data about at home food frequency at the beginning and the end of the school year and the results compared. The parents were given a demonstration of the educational objectives and the students played the game throughout the year. By the end of the school year there was a statistically significant increase in the vegetables offered to this population both during the week at home (p = 0.009) and on the weekends (p = 0.02).

Parenting Interventions in Early Head Start: The Buffering Toxic Stress Consortium

Science.gov (United States)

Berlin, Lisa; Blair, Clancy; Boyd, Misty L.; Constantino, John N.; Hallam, Rena A.; Han, Myae; Hustedt, Jason; Harden, Brenda Jones; Raver, C. Cybele; Sarche, Michelle; Vu, Jennifer A.; Watamura, Sarah Enos; Meyer, Aleta; Fortunato, Christine

2013-01-01

The Buffering Toxic Stress Consortium was created by the Office of Planning, Research and Evaluation within the Administration for Children and Families to test preventive interventions for Early Head Start families facing toxic stress, as conceptualized by Shonkoff, Boyce, and McEwen in their influential 2009 article. Because relationships…

Head Start Program Quality: Examination of Classroom Quality and Parent Involvement in Predicting Children's Vocabulary, Literacy, and Mathematics Achievement Trajectories

Science.gov (United States)

Wen, Xiaoli; Bulotsky-Shearer, Rebecca J.; Hahs-Vaughn, Debbie L.; Korfmacher, Jon

2012-01-01

Guided by a developmental-ecological framework and Head Start's two-generational approach, this study examined two dimensions of Head Start program quality, classroom quality and parent involvement and their unique and interactive contribution to children's vocabulary, literacy, and mathematics skills growth from the beginning of Head Start…

Head Start Evaluation and Research Center, University of Kansas. Report No. VIII, Physical Development of Children in the Head Start Program in the Central United States.

Science.gov (United States)

Bass, William; And Others

Information on the nutritional habits of 154 Head Start children from rural, small city, and metropol tan areas in the central United States was obtained from questionnaires answered by the children's mothers. The information was restricted to what foods the children liked and disliked, except that a determination of the quantity of milk consumed…

Optimal feeding frequency of captive head-started green turtles (Chelonia mydas).

Science.gov (United States)

Kanghae, H; Thongprajukaew, K; Yeetam, P; Jarit-Ngam, T; Hwan-Air, W; Rueangjeen, S; Kittiwattanawong, K

2017-08-01

Optimal feeding frequency was investigated to improve head-started propagation programme of juvenile green turtles (Chelonia mydas). The 15-day-old turtles (25-26 g body weight) were fed for ad libitum intake at one (1MD), two (2MD), three (3MD) or four (4MD) meals daily over a 3-month trial. Responses in growth, feed utilization, faecal characteristics, haematological parameters and carapace elemental composition were used to compare treatment effects. At the end of the feeding trial, no treatment had induced mortality. Growth performance in terms of weight gain and specific growth rate was similar in turtles fed 2MD, 3MD or 4MD (p > 0.05), but 1MD differed from these (p Turtles fed 2MD had significantly lower feed intake than in 3MD and 4MD groups, but the feed conversion ratios were similar. Faecal digestive enzyme analysis indicated higher catabolism of lipid and protein in the deprivation group (1MD), when compared with turtles fed at least twice daily. The feeding frequency did not affect the specific activities of carbohydrate-digesting enzymes. The results on enzymes activities were corroborated by the transition enthalpy characteristics of faeces, indicating nutrients remaining after digestion. The 2MD treatment also improved the haematological characteristics and the carapace quality, relative to low or excess feeding. Overall, the findings indicate that feeding juvenile green turtles twice a day is the preferred option in their head-started propagation. This promotes growth, reduces feed consumption, and improves health and carapace quality. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Examination of Head Start students' and teachers' attitudes and behaviors toward trying new foods as part of a social marketing campaign

OpenAIRE

Stratton, Jessica Nicole

2008-01-01

Objective: To determine the impact of preschool teacher food-related attitudes and behaviors on child food behaviors. Design: A twelve-week intervention and observational study with teachers completing questionnaires before and after the intervention. Setting: Head Start classrooms throughout Virginia. Participants: 177 preschool Head Start teachers and 1534 children. Intervention(s): Food Friends, a twelve-week social marketing campaign, was conducted by Head Start teac...

Building Social Competence in Preschool: The Effects of a Social Skills Intervention Targeting Children Enrolled in Head Start

Science.gov (United States)

Stanton-Chapman, Tina L.; Walker, Virginia; Jamison, Kristen R.

2014-01-01

The current study evaluated the peer-to-peer interactions of at-risk children enrolled in Head Start who participated in a social pragmatic intervention targeting skills such as initiations, responses, name use, proximity, and turn-taking skills. Eight Head Start classroom teams received two workshops and two coaching sessions and were taught to…

Occupational Therapy in the Context of Head Start: A Preliminary Survey Study

Science.gov (United States)

Bowyer, Patricia; Moore, Cary C.; Thom, Carly

2016-01-01

This preliminary, descriptive study yields information on the utilization of occupational therapy services within Head Start programs. Participants completed an Internet-based survey of 25 questions pertaining to the understanding, scope, and utilization of occupational therapy services. Surveys were completed by 35 respondents nationwide. A total…

Teacher Perceptions of Multilevel Policies and the Influence on Nutrition Education in North Carolina Head Start Preschools.

Science.gov (United States)

Peterson, Amanda D; Goodell, L Suzanne; Hegde, Archana; Stage, Virginia C

2017-05-01

To develop a theory that explains the process of how teachers' perception of multilevel policies may influence nutrition education (NE) teaching strategies in Head Start preschools. Semistructured telephone interviews. North Carolina Head Start preschools. Thirty-two Head Start teachers. All interviews were transcribed verbatim. Following a grounded theory approach, authors coded interview data for emergent themes. Two primary themes emerged during analysis, including teachers' policy perceptions and teacher-perceived influence of policy on NE. A theoretical model was developed to explain how teachers' perceptions of policies influenced NE (eg, teaching strategies) in the classroom. Teachers discussed multiple policy areas governing their classrooms and limiting their ability to provide meaningful and consistent NE. How teachers perceived the level of regulation in the classroom (ie, high or low) influenced the frequency with which they used specific teaching strategies. Despite federal policies supporting the provision of NE, teachers face competing priorities in the classroom (eg, school readiness vs NE) and policies may conflict with standardized NE curricula. To understand how Head Start centers develop local policies, additional research should investigate how administrators interpret federal and state policies. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Methods That Examine the Extent to Which the Quality of Children's Experiences in Elementary School Moderate the Long-Term Impacts of Head Start

Science.gov (United States)

Mashburn, Andrew J.; Downer, Jason T.

2013-01-01

The goals of the Head Start Impact Study (HSIS) are to: (1) determine the impacts of Head Start on children's school readiness and parental practices that support children's development; and (2) to determine under what circumstances Head Start achieves its greatest impacts and for which children (US Department of Health and Human Services, 2010).…

National Profiles of Classroom Quality and Family Involvement: A Multilevel Examination of Proximal Influences on Head Start Children's School Readiness

Science.gov (United States)

Bulotsky-Shearer, Rebecca J.; Wen, Xiaoli; Faria, Ann-Marie; Hahs-Vaughn, Debbie L.; Korfmacher, Jon

2012-01-01

Guided by a developmental and ecological model, the study employed latent profile analysis to identify a multilevel typology of family involvement and Head Start classroom quality. Using the nationally representative Head Start Family and Child Experiences Survey (FACES 1997; N = 1870), six multilevel latent profiles were estimated, characterized…

Early Head Start and African American Families: Impacts and Mechanisms of Child Outcomes

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Harden, Brenda Jones; Sandstrom, Heather; Chazan-Cohen, Rachel

2012-01-01

Persistent disparities exist between African American children and their European American counterparts across developmental domains. Early childhood intervention may serve to promote more positive outcomes among African American children. The current study examined whether and how the Early Head Start (EHS) program benefited African American…

NAP SACC: Implementation of an Obesity Prevention Intervention in an American Indian Head Start Program.

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Mattingly, Julie A; Andresen, Pamela A

2016-01-01

Low-income American Indian preschoolers are at greatest risk for overweight and obesity among children aged 2-5 years. The Nutrition and Physical Activity Self-Assessment for Child Care (NAP SACC) program is an evidence-based intervention that promotes healthy weight development for children enrolled in child care centers. The goal of this continuous quality improvement program is for the child care staff to establish environmental policies and practices that positively influence nutrition and physical activity-related behaviors. A community needs assessment of a Head Start program on an American Indian reservation identified obesity as a priority issue. This project implemented NAP SACC at 15 Head Start sites on the reservation.

A Comparison of Developmental Sentence Scores from Head Start Children Collected in Four Conditions

Science.gov (United States)

Longhurst, Thomas M.; File, Judy J.

1977-01-01

In a comparison of expressive language in different settings, 20 economically disadvantaged students in a Head Start program were divided into four groups: single-object picture, toy, multi-object picture, and adult-child conversation. (CL)

Key parameters of the swimming start and their relationship to start performance.

Science.gov (United States)

Tor, Elaine; Pease, David L; Ball, Kevin A

2015-01-01

The swimming start is typically broken into three sub-phases; on-block, flight, and underwater phases. While overall start performance is highly important to elite swimming, the contribution of each phase and important technical components within each phase, particularly with the new kick-start technique, has not been established. The aim of this study was to identify technical factors associated with overall start performance, with a particular focus on the underwater phase. A number of parameters were calculated from 52 starts performed by elite freestyle and butterfly swimmers. These parameters were split into above-water and underwater groupings, before factor analysis was used to reduce parameter numbers for multiple regression. For the above-water phases, 81% of variance in start performance was accounted for by take-off horizontal velocity. For the underwater water phase, 96% of variance was accounted for with time underwater in descent, time underwater in ascent and time to 10 m. Therefore, developing greater take-off horizontal velocity and focussing on the underwater phase by finding the ideal trajectory will lead to improved start performance.

Training Head Start Teachers to Conduct Trial-Based Functional Analysis of Challenging Behavior

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Rispoli, Mandy; Burke, Mack D.; Hatton, Heather; Ninci, Jennifer; Zaini, Samar; Sanchez, Lisa

2015-01-01

Trial-based functional analysis (TBFA) is a procedure for experimentally identifying the function of challenging behavior within applied settings. The purpose of this study was to examine the effects of a TBFA teacher-training package in the context of two Head Start centers implementing programwide positive behavior support (PWPBS). Four Head…

Expanding Exposure: Can Increasing the Daily Duration of Head Start Reduce Childhood Obesity?

Science.gov (United States)

Frisvold, David E.; Lumeng, Julie C.

2011-01-01

Coinciding with the work requirements of welfare reform in the mid-1990s, the early childhood education program, Head Start, significantly expanded to increase the availability of full-day classes. Using unique administrative data, we examine the effect of full-day compared to half-day attendance on childhood obesity. This effect is identified…

Nutritional Status of New Orleans, Mississippi and Alabama Head Start Children. Final Report.

Science.gov (United States)

Smith, Jack L.

Three purposes guided compilation of this final report on the nutritional status of New Orleans, Mississippi, and Alabama Head Start children: (1) to evaluate the causes of anemia through detailed studies of urban New Orleans preschool children and their mothers, (2) to study the effect of dietary supplementation of school feeding programs upon…

Potential for misclassification of micronutrient status in children participating in a Head Start program.

Science.gov (United States)

Droke, Elizabeth A; Kennedy, Tay Seacord; Hubbs-Tait, Laura

2006-03-01

To evaluate relations among measures of iron and zinc status, C-reactive protein (CRP), and leukocytes in low-income children participating in the Head Start program. Cross-sectional correlational study with samples collected at Head Start centers in May 2003. Forty-seven children (aged 3 to 5 years) attending Head Start centers in three rural communities. Zinc, ferritin, CRP, and complete blood count were analyzed in nonfasting blood samples. Correlations were computed among leukocyte levels, CRP levels, and measures of micronutrient status. Children having two abnormal measures (ie, leukocytes and CRP) were compared by univariate analysis of variance with children having zero or one abnormal measure. Most (72%) of the children had elevated CRP levels. Four percent were anemic (hemoglobinreference value that accounts for the presence of infection was used (serum ferritin

Associations among Head Start Fathers' Involvement with Their Preschoolers and Child Language Skills

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Fagan, Jay; Iglesias, Aquiles; Kaufman, Rebecca

2016-01-01

This study examined the associations among child language competence during father-child play interactions, fathers' time spent volunteering in their preschool-age child's Head Start classroom over the course of one school year, amount of father play and reading to the child at home, and fathers' positive control during play. The sample of 68…

Users' Manual for Research: Translating Head Start Findings Into Action (Expanded Notebook Version).

Science.gov (United States)

Grotberg, Edith H.; Fowler, Austine

This users' manual, intended for use with a Project Head Start teacher training notebook, describes the purpose, development and field testing of the training materials and suggests procedures for using the notebook as a resource in teacher training sessions. The training notebook to which the users' manual refers is based on 11 questions in the…

Caregiver Emotional Expressiveness, Child Emotion Regulation, and Child Behavior Problems among Head Start Families

Science.gov (United States)

McCoy, Dana Charles; Raver, C. Cybele

2011-01-01

The present study examined the relationships between caregivers' self-reported positive and negative emotional expressiveness, observer assessments of children's emotion regulation, and teachers' reports of children's internalizing and externalizing behaviors in a sample of 97 primarily African American and Hispanic Head Start families. Results…

Best Practices and Barriers to Obesity Prevention in Head Start: Differences Between Director and Teacher Perceptions.

Science.gov (United States)

Byrd-Williams, Courtney; Dooley, Erin E; Sharma, Shreela V; Chuang, Ru-Jye; Butte, Nancy; Hoelscher, Deanna M

2017-12-21

Practices and barriers to promoting healthy eating and physical activity at Head Start centers may influence children's energy balance behaviors. We examined differences between directors' and teachers' perspectives on best practices and barriers to promoting healthy eating and physical activity in Head Start centers. We conducted a cross-sectional study of directors (n = 23) and teachers (n = 113) at 23 Head Start centers participating in the baseline assessment of the Texas Childhood Obesity Research Demonstration study. Participants completed surveys about practices and barriers to promoting healthy eating and physical activity. Multilevel regression models examined differences between director and teacher responses. More than half of directors and teachers reported meeting most best practices related to nutrition and physical activity; few directors or teachers (foods (especially sweets, salty snacks, and sugary drinks) in front of children" and "Teachers talk to children about trying/enjoying new foods" (P food service staff support, limited time, and insufficient funds (P < .05). More barriers to healthy eating were reported than were barriers to physical activity indicating that more support may be needed for healthy eating. Differences between responses of directors and teachers may have implications for future assessments of implementation of best practices and barriers to implementation related to nutrition and physical activity in early care and education centers.

Understanding the State of Nutrition Education in the Head Start Classroom: A Qualitative Approach

Science.gov (United States)

Carraway-Stage, Virginia; Henson, Sydney R.; Dipper, Allison; Spangler, Hillary; Ash, Sarah L.; Goodell, L. Suzanne

2014-01-01

Background: Early education is important for establishing healthy eating behaviors among young children; however, the literature describing nutrition education in the preschool environment is limited. Purpose: The purpose of this study was to explore teacher experiences related to the incorporation of nutrition education in Head Start preschool…

Effect of flame-tube head structure on combustion chamber performance

Science.gov (United States)

Gu, Minqqi

1986-01-01

The experimental combustion performance of a premixed, pilot-type flame tube with various head structures is discussed. The test study covers an extensive area: efficiency of the combustion chamber, quality of the outlet temperature field, limit of the fuel-lean blowout, ignition performance at ground starting, and carbon deposition. As a result of these tests, a nozzle was found which fits the premixed pilot flame tube well. The use of this nozzle optimized the performance of the combustion chamber. The tested models had premixed pilot chambers with two types of air-film-cooling structures, six types of venturi-tube structures, and secondary fuel nozzles with two small spray-cone angles.

Neighborhood Economic Disadvantage and Children's Cognitive and Social-Emotional Development: Exploring Head Start Classroom Quality as a Mediating Mechanism.

Science.gov (United States)

McCoy, Dana Charles; Connors, Maia C; Morris, Pamela A; Yoshikawa, Hirokazu; Friedman-Krauss, Allison H

Past research has shown robust relationships between neighborhood socioeconomic disadvantage and children's school achievement and social-emotional outcomes, yet the mechanisms for explaining these relationships are poorly understood. The present study uses data from 1,904 Head Start participants enrolled in the Head Start Impact Study to examine the role that classroom structural and relational quality play in explaining the association between neighborhood poverty and children's developmental gains over the preschool year. Results suggest that neighborhood poverty is directly related to lower levels of classroom quality, and lower gains in early literacy and math scores. Indirect relationships were also found between neighborhood poverty and children's social-emotional outcomes (i.e., approaches to learning and behavior problems) via differences in the physical resources and negative student-teacher relationships within classrooms. These findings highlight the need for policy initiatives to consider community characteristics as potential predictors of disparities in classroom quality and children's cognitive and social-emotional development in Head Start.

Theory of Mind Predicts Emotion Knowledge Development in Head Start Children.

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Seidenfeld, Adina M; Johnson, Stacy R; Cavadel, Elizabeth Woodburn; Izard, Carroll E

2014-10-01

Emotion knowledge (EK) enables children to identify emotions in themselves and others and its development facilitates emotion recognition in complex social situations. Social-cognitive processes, such as theory of mind (ToM), may contribute to developing EK by helping children realize the inherent variability associated with emotion expression across individuals and situations. The present study explored how ToM, particularly false belief understanding, in preschool predicts children's developing EK in kindergarten. Participants were 60 3- to 5-year-old Head Start children. ToM and EK measures were obtained from standardized child tasks. ToM scores were positively related to performance on an EK task in kindergarten after controlling for preschool levels of EK and verbal ability. Exploratory analyses provided preliminary evidence that ToM serves as an indirect effect between verbal ability and EK. Early intervention programs may benefit from including lessons on ToM to help promote socio-emotional learning, specifically EK. This consideration may be the most fruitful when the targeted population is at-risk.

Professional Development Aimed at Increasing the Quality of Language Input during Storybook Interactions: Lessons from One Head Start Teacher's Experiences

Science.gov (United States)

O'Keefe, Casey

2018-01-01

This article provides a review of problems associated with teachers' talk and indicators of higher quality teachers' talk for use with lower socioeconomic status (SES) Head Start students. Then it shows how one Head Start teacher, called Michele in this article, responded to professional development that was aimed at increasing the quality of…

Investigating Maternal Self-Efficacy and Home Learning Environment of Families Enrolled in Head Start

Science.gov (United States)

Bojczyk, Kathryn Elizabeth; Haverback, Heather Rogers; Pae, Hye K.

2018-01-01

The aim of this study was to examine the relationships between mothers' self-efficacy beliefs, their preschool children's home learning environments, and literacy skills. A sample of 112 mother-child dyads was recruited from Head Start centers in rural and urban communities. The measures included maternal self-efficacy and maternal perceptions of…

Parent training in head start: a comparison of program response among African American, Asian American, Caucasian, and Hispanic mothers.

Science.gov (United States)

Reid, M J; Webster-Stratton, C; Beauchaine, T P

2001-12-01

The effectiveness of the Incredible Years Parenting Program was evaluated in a low-income sample of Caucasian, African American, Hispanic, and Asian mothers whose children were enrolled in Head Start. Data from two prior intervention studies [Webster-Stratton (1998) Journal of Consulting and Clinical Psychology, 66(5), 715-730; Webster-Stratton et al. (in press) Journal of Clinical Child Psychology] were combined, yielding a sample of 634 families (370 Caucasian, 120 African American, 73 Asian, 71 Hispanic) across 23 Head Start centers. Centers were matched and assigned randomly to either an experimental condition (8-12 weeks of weekly 2-hr parenting classes), or a control condition (the regular Head Start Program without parenting groups). Families in both conditions were assessed using home observations of parent-child interactions and parent reports of parenting style and discipline strategies and child behavior problems in the fall (baseline) and spring (postintervention) of the children's Head Start year. Families were reassessed 1 year later. Following treatment, intervention mothers were observed to be more positive, less critical, more consistent, and more competent in their parenting than were control mothers. Additionally, children of intervention parents were observed to exhibit fewer behavior problems than were control children. Differences in treatment response across ethnic groups were few, and did not exceed the number expected by chance. Parents from all groups reported high satisfaction levels following the parenting program. Results indicate that the Incredible Years Program is accepted by and effective with diverse populations.

Playing with Daddy: Social Toy Play, Early Head Start, and Developmental Outcomes

OpenAIRE

Roggman, Lori A.; Boyce, Lisa; Cook, G. A.; Christiansen, K.; Jones, D.

2007-01-01

Research on fathers in Early Head Start (EHS) has provided an opportunity to study fathers from low-income families. We examined father-toddler social toy play in relation to EHS enrollment, fathers' psychosocial well-being, and children's developmental outcomes in a sample of 74 father-toddler dyads. Overall, our results show that father-toddler social toy play was more complex among fathers in an EHS program than among those in a comparison group. Greater complexity in father-toddler social...

Exploring Teachers' Depressive Symptoms, Interaction Quality, and Children's Social-Emotional Development in Head Start

Science.gov (United States)

Roberts, Amy; LoCasale-Crouch, Jennifer; Hamre, Bridget; DeCoster, Jamie

2016-01-01

Research Findings: This study explored the role Head Start teachers' (n = 355) depressive symptoms play in their interactions with children and in children's (n = 2,203) social-emotional development, specifically changes in children's problem behaviors and social skills as reported by parents and teachers during the preschool year. Results of the…

"Ganchulinas" and "Rainbowli" Colors: Young Multilingual Children Play with Language in Head Start Classroom

Science.gov (United States)

Axelrod, Ysaaca

2017-01-01

The purpose of this ethnographic case study was to study the language development of 4-year-old emergent bilinguals in a bilingual (Spanish/English) Head Start classroom with flexible language practices. Data were collected throughout the 10-month school year by visiting the classroom 2-3 times per week. Data include: field notes (observations and…

Cultural Capital Theory: A Study of Children Enrolled in Rural and Urban Head Start Programmes

Science.gov (United States)

Bojczyk, Kathryn E.; Rogers-Haverback, Heather; Pae, Hye; Davis, Anna E.; Mason, Rihana S.

2015-01-01

Children from different backgrounds have disparate access to cultural capital, which may influence their academic success. The purpose of this study was to examine the links between family background, home literacy experiences, and emergent literacy skills among preschoolers enrolled in Head Start programmes. The background characteristics studied…

A Program Evaluation Comparison of a Head Start and Public School Kindergarten Reading Curriculum

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Jennings, Tanesha

2014-01-01

In order for students to be successful in school, strong foundations are needed at the earliest grades. In a district in central Mississippi, many students entering public school from Head Start were not able to identify alphabet letters or produce letter sounds, based on results of the 2011 Standardized Test for the Assessment of Reading (STAR).…

Nutrition Education Resources in North Carolina-Based Head Start Preschool Programs: Administrator and Teacher Perceptions of Availability and Use.

Science.gov (United States)

Lisson, Sarah; Goodell, L Suzanne; Dev, Dipti; Wilkerson, Kristi; Hegde, Archana V; Stage, Virginia C

2016-10-01

The purpose of this study was to provide new insight into common barriers to the availability and use of nutrition education (NE) resources in Head Start preschool programs based on administrator and teacher perceptions. In-depth, semistructured phone interviews (n = 63) were conducted with administrators (n = 31) and teachers (n = 32) from North Carolina-based Head Start programs. Interviews were audio-recorded and transcribed verbatim. Data were analyzed qualitatively using content analysis to identify common themes. Five emergent themes were identified within the areas of NE resource availability and use and barriers to NE resource availability and use. Participants expressed desire for greater organization of existing NE material resources, increased community support, and professional development opportunities for teachers specific to NE. Funding and time constraints were reported as affecting NE resources. Creative strategies for addressing NE resource availability and use and barriers (eg, NE integration with educational standards) in Head Start are needed. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Supporting Head Start Parents: Impact of a Text Message Intervention on Parent-Child Activity Engagement

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Hurwitz, Lisa B.; Lauricella, Alexis R.; Hanson, Ann; Raden, Anthony; Wartella, Ellen

2015-01-01

Head Start emphasises parent engagement as a critical strategy in promoting children's long-term learning. Parents can support children's positive development by engaging them in stimulating activities. The following study assessed whether a service that delivered parenting tips via text message could prompt parents of children enrolled in Head…

Teacher Education, Book-Reading Practices, and Children's Language Growth across One Year of Head Start

Science.gov (United States)

Gerde, Hope K.; Powell, Douglas R.

2009-01-01

Research Findings: An observational study of 60 Head Start teachers and 341 children (177 boys, 164 girls) enrolled in their classrooms found teachers' book-reading practices to predict growth in children's receptive vocabulary. Multilevel growth analyses indicated that children in classrooms where teachers used more book-focused utterances made…

Home Literacy Environment and Head Start Children's Language Development: The Role of Approaches to Learning

Science.gov (United States)

Meng, Christine

2015-01-01

Research Findings: This study examined whether approaches to learning moderate the association between home literacy environment and English receptive vocabulary development. The Head Start Family and Child Experiences Survey (2003 cohort) was used for analysis. Latent growth curve modeling was utilized to test a quadratic model of English…

Using "I Am Moving, I Am Learning" to Increase Quality Instruction in Head Start Classrooms

Science.gov (United States)

Allar, Ishonté; Jones, Emily; Bulger, Sean

2018-01-01

Quality teacher-child interactions are characteristic of effective classrooms resulting in benefits for all children, but may be particularly important for children from low-income families. The purpose of this study was to explore the perception of Illinois Head Start teachers related to how "I am Moving, I am Learning" (IMIL) could…

Financial Reporting and Cost Analysis Manual for Day Care Centers, Head Start, and Other Programs.

Science.gov (United States)

Bedger, Jean E.; And Others

This manual is designed to provide fundamental directions for systematic financial reporting and cost analysis for the administrators, accountants, bookkeepers, and staff of day care, Project Head Start, and other programs. The major aims of the manual are to induce day care directors to adopt uniform bookkeeping procedures and to analyze costs…

African American and Puerto Rican American Parenting Styles, Paternal Involvement, and Head Start Children's Social Competence.

Science.gov (United States)

Fagan, Jay

2000-01-01

Examined similarities and differences in parenting styles and paternal involvement within and between African American and Puerto Rican American parent groups and the relationship between parenting styles, child care involvement, and Head Start children's social competence. Found a significant relationship between high levels of parental…

Using Meta-Analysis to Explain Variation in Head Start Research Results: The Role of Research Design

Science.gov (United States)

Shager, Hilary M.; Schindler, Holly S.; Hart, Cassandra M.D.; Duncan, Greg J.; Magnuson, Katherine A.; Yoshikawa, Hirokazu

2010-01-01

Head Start was designed as a holistic intervention to improve economically disadvantaged, preschool-aged children's cognitive and social development by providing a comprehensive set of educational, health, nutritional, and social services, as well as opportunities for parent involvement (Zigler & Valentine, 1979). Given the current interest in ECE…

Perceived Parental Barriers to and Strategies for Supporting Physical Activity and Healthy Eating among Head Start Children.

Science.gov (United States)

Ling, Jiying; B Robbins, Lorraine; Hines-Martin, Vicki

2016-06-01

Despite the need for parents to support their children's healthy behaviors, knowledge of factors preventing parents from doing so is still rudimentary. This study primarily aimed to explore perceived parental barriers to and strategies for supporting physical activity and healthy eating among Head Start children. A semi-structured interview format was used with four focus groups conducted at two urban Head Start centers in the Midwestern U.S. A qualitative content analysis of audio-recorded sessions was facilitated using ATLAS.ti7. A convenience sample of 32 parents (Mage = 34.97 years) participated. Over half were female (78.1 %), African Americans (65.6 %), and single (65.6 %). About 61.3 % reported an annual family income parent): lack of time and cooking skills and a tight family budget; and (3) environmental: inaccessible programs, lack of age-appropriate education, electronic media use, and unsafe environment. Parents across all groups expressed high interest in enrolling in a program with their children. Recommendations included: parents' support team; family outings at parks; taking a walk or enrolling in a class with children; and planting a garden. Many parents showed their preference for face-to-face meetings and a support group, but repulsion of counseling. To promote parental support in future interventions with Head Start children, their perceived intrapersonal, interpersonal, and environmental barriers should be considered as intervention targets. Involving parents through a support group and face-to-face meetings is recommended.

Cross-sectional evaluation of visuomotor tracking performance following subconcussive head impacts.

Science.gov (United States)

Brokaw, E B; Fine, M S; Kindschi, K E; Santago Ii, A C; Lum, P S; Higgins, M

2018-01-01

Repeated mild traumatic brain injury (mTBI) has been associated with increased risk of degenerative neurological disorders. While the effects of mTBI and repeated injury are known, studies have only recently started examining repeated subconcussive impacts, impacts that do not result in a clinically diagnosed mTBI. In these studies, repeated subconcussive impacts have been connected to cognitive performance and brain imaging changes. Recent research suggests that performance on a visuomotor tracking (VMT) task may help improve the identification of mTBI. The goal of this study was to investigate if VMT performance is sensitive to the cumulative effect of repeated subconcussive head impacts in collegiate men's lacrosse players. A cross-sectional, prospective study was completed with eleven collegiate men's lacrosse players. Participants wore helmet-mounted sensors and completed VMT and reaction time assessments. The relationship between cumulative impact metrics and VMT metrics were investigated. In this study, VMT performance correlated with repeated subconcussive head impacts; individuals approached clinically diagnosed mTBI-like performance as the cumulative rotational velocity they experienced increased. This suggests that repeated subconcussive impacts can result in measurable impairments and indicates that visuomotor tracking performance may be a useful tool for monitoring the effects of repeated subconcussive impacts.

The Influence of an Early Childhood Program on Parental Involvement: Perceptions of Former Head Start Parents

Science.gov (United States)

Croft, Stacey

2017-01-01

A key component of effective early childhood programs is collaborative relationships between schools, families, and the community (Fiese, Eckert, & Spagnola, 2005). One of these early childhood programs, Head Start, stands out among the others in its efforts to work with children, families, and communities to promote parental involvement. Some…

Identifying Head Start and Public Pre-K Participation in NSECE Data on Center-Based ECE Programs. NSECE Technical Report Supplement. OPRE Report 2015-92b

Science.gov (United States)

Goerge, Robert; Datta, A. Rupa; Xia, Kanru; Witte, Ann D.; Gennetian, Lisa A.; Milesi, Carolina; Brandon, Richard; Guzman, Lina; Zanoni, Wladimir

2015-01-01

The analyses presented in the Technical Report, "Which Centers Participate in Head Start or Public Pre-Kindergarten" characterize centers that have at least one child whose enrollment is funded through Head Start or Public Pre-K funds. This supplement to the technical report provides interested readers with technical details of the…

Early Head Start: Factors Associated with Caregiver Knowledge of Child Development, Parenting Behavior, and Parenting Stress

Science.gov (United States)

Belcher, Harolyn M. E.; Watkins, Katara; Johnson, Elizabeth; Ialongo, Nicholas

2007-01-01

This study investigates the role of socioeconomic status, parental mental health, and knowledge of child development on parenting styles and perceived parenting stress in caregivers of children, ages 3 months to 3 years, enrolled in Early Head Start (EHS). Caregivers of EHS students were interviewed using the Knowledge of Infant Development…

Enhancing start performance in the sport of skeleton

OpenAIRE

Colyer, Steffi

2015-01-01

A fast start is considered to be crucial in skeleton with marginal gains in start performance perceived to make meaningful improvements to overall chances of success. Currently, knowledge surrounding the underlying determinants of start performance is sparse and training practices are based on limited scientific evidence. A series of investigations were conducted to advance this understanding.Initial observations revealed similarities between dry-land push-starts and those on ice tracks. Howe...

The Role of Early Head Start Programs in Addressing the Child Care Needs of Low-Income Families with Infants and Toddlers: Influences on Child Care Use and Quality.

Science.gov (United States)

Love, John M.; Constantine, Jill; Paulsell, Diane; Boller, Kimberly; Ross, Christine; Raikes, Helen; Brady-Smith, Christy; Brooks-Gunn, Jeanne

2004-01-01

In 1994, the Secretary's Advisory Committee on Services for Families with Infants and Toddlers set forth a vision for Early Head Start programs in declaring that all child care settings used by Early Head Start families, whether or not the program provides the care directly, must meet the high standards of quality embodied in the Head Start…

Parent-Child Book-Reading Styles, Emotional Quality, and Changes in Early Head Start Children's Cognitive Scores

Science.gov (United States)

Cline, Keely D.; Edwards, Carolyn Pope

2017-01-01

Research Findings: The objective of this study was to understand how instructional book-reading style and emotional quality of reading interact and relate to cognitive skills in a sample of at-risk infants and toddlers. Participants were 81 parents and their children participating in Early Head Start programs in the rural Midwest. Correlation and…

Scheduling of head-dependent cascaded reservoirs considering discharge ramping constraints and start/stop of units

Energy Technology Data Exchange (ETDEWEB)

Catalao, J.P.S.; Pousinho, H.M.I. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal)

2010-10-15

This paper is on the problem of short-term hydro scheduling (STHS), particularly concerning head-dependent reservoirs under competitive environment. We propose a novel method, based on mixed-integer nonlinear programming (MINLP), for optimising power generation efficiency. This method considers hydroelectric power generation as a nonlinear function of water discharge and of the head. The main contribution of this paper is that discharge ramping constraints and start/stop of units are also considered, in order to obtain more realistic and feasible results. The proposed method has been applied successfully to solve two case studies based on Portuguese cascaded hydro systems, providing a higher profit at an acceptable computation time in comparison with classical optimisation methods based on mixed-integer linear programming (MILP). (author)

Cultural/Favorite Recipe Day: Strengthening Approaches to Increase Culturally Diverse Foods Served in Head Start Meals

Science.gov (United States)

Hoffman, Jessica A.; Agrawal, Tara; Carter, Sonia; Grinder, AnnMarie; Castaneda-Sceppa, Carmen

2012-01-01

One approach to halting the childhood obesity epidemic has been the modification of foods available to children during the school day. In recent years there has been an increased focus on obesity prevention efforts among children ages birth to 5 and the role of child care settings in prevention efforts. Head Start serves as an important venue for…

A Demonstration of the Universal Problem-Solving Approach to Address Children's Inappropriate Behavior in Head Start Classrooms

Science.gov (United States)

Snell, Martha E.; Voorhees, Mary D.; Walker, Virginia L.; Berlin, Rebecca A.; Jamison, Kristen Roorbach; Stanton-Chapman, Tina L.

2014-01-01

The purpose of this demonstration was to evaluate a universal intervention during teacher-identified routines that were characterized by significant classwide problem behavior. Six Head Start classrooms (seven groups of children, with one classroom divided into two groups) received two workshops and two coaching sessions on universal Positive…

Effects of Head Start Hours on Children's Cognitive, Pre-Academic, and Behavioral Outcomes: An Instrumental Variable Analysis

Science.gov (United States)

Li, Weilin; Farkas, George; Duncan, Greg J.; Vandell, Deborah Lowe; Burchinal, Margaret

2013-01-01

Children from low-income families benefit remarkably from exposure to compensatory education that began with Head Start in 1965 and aimed to improve school readiness skills by design. While empirical evidence has supported more instructional time in elementary and secondary schools for low-income students, little is known that whether increasing…

Heading Frequency Is More Strongly Related to Cognitive Performance Than Unintentional Head Impacts in Amateur Soccer Players

Directory of Open Access Journals (Sweden)

Walter F. Stewart

2018-04-01

Full Text Available ObjectiveCompared to heading, unintentional head impacts (e.g., elbow to head, head to head, head to goalpost in soccer are more strongly related to risk of moderate to very severe Central Nervous System (CNS symptoms. But, most head impacts associated with CNS symptoms that occur in soccer are mild and are more strongly related to heading. We tested for a differential relation of heading and unintentional head impacts with neuropsychological (NP test performance.MethodActive adult amateur soccer players were recruited in New York City and the surrounding areas for this repeated measures longitudinal study of individuals who were enrolled if they had 5+ years of soccer play and were active playing soccer 6+ months/year. All participants completed a baseline validated questionnaire (“HeadCount-2w”, reporting 2-week recall of soccer activity, heading and unintentional head impacts. In addition, participants also completed NP tests of verbal learning, verbal memory, psychomotor speed, attention, and working memory. Most participants also completed one or more identical follow-up protocols (i.e., HeadCount-2w and NP tests at 3- to 6-month intervals over a 2-year period. Repeated measures General Estimating Equations (GEE linear models were used to determine if variation in NP tests at each visit was related to variation in either heading or unintentional head impacts in the 2-week period before testing.Results308 players (78% male completed 741 HeadCount-2w. Mean (median heading/2-weeks was 50 (17 for men and 26 (7 for women. Heading was significantly associated with poorer performance on psychomotor speed (p < 0.001 and attention (p = 0.02 tasks and was borderline significant with poorer performance on the working memory (p = 0.06 task. Unintentional head impacts were not significantly associated with any NP test. Results did not differ after excluding 22 HeadCount-2w with reported concussive or borderline concussive symptoms

Barriers and Facilitators to Healthy Eating and Activity in Head Start Staff: An Opportunity for Worksite Wellness

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Hibbs-Shipp, Sarah K.; Milholland, Michelle; Bellows, Laura

2015-01-01

Background: Head Start (HS) staff are ideally positioned to promote healthy behaviors to over one million low-income children each year, however little is understood about their own health. Purpose: To conduct a needs assessment with HS staff to: 1) understand perceptions, barriers and motivators to healthful behaviors; and 2) ascertain interest…

Resilient Partners: The Development of a University-Community Collaboration to Promote Wellness for Head Start Children and Families

Science.gov (United States)

Mendez, Julia L.; Lloyd, Blake Te'Neil

2005-01-01

This paper describes a theoretically driven approach uniquely suited for the development of research partnerships between university teams and local communities serving children enrolled in Head Start programs. A literature review on dimensions of successful research partnerships provides a backdrop for presenting the Resilience…

EARLY HEAD START FAMILIES' EXPERIENCES WITH STRESS: UNDERSTANDING VARIATIONS WITHIN A HIGH-RISK, LOW-INCOME SAMPLE.

Science.gov (United States)

Hustedt, Jason T; Vu, Jennifer A; Bargreen, Kaitlin N; Hallam, Rena A; Han, Myae

2017-09-01

The federal Early Head Start program provides a relevant context to examine families' experiences with stress since participants qualify on the basis of poverty and risk. Building on previous research that has shown variations in demographic and economic risks even among qualifying families, we examined possible variations in families' perceptions of stress. Family, parent, and child data were collected to measure stressors and risk across a variety of domains in families' everyday lives, primarily from self-report measures, but also including assay results from child cortisol samples. A cluster analysis was employed to examine potential differences among groups of Early Head Start families. Results showed that there were three distinct subgroups of families, with some families perceiving that they experienced very high levels of stress while others perceived much lower levels of stress despite also experiencing poverty and heightened risk. These findings have important implications in that they provide an initial step toward distinguishing differences in low-income families' experiences with stress, thereby informing interventions focused on promoting responsive caregiving as a possible mechanism to buffer the effects of family and social stressors on young children. © 2017 Michigan Association for Infant Mental Health.

Which Early Care and Education Centers Participate in Head Start or Public Pre-Kindergarten? National Survey of Early Care & Education. Technical Report. OPRE Report 2015-92a

Science.gov (United States)

Administration for Children & Families, 2015

2015-01-01

This report draws on newly available data from the National Survey of Early Care and Education (NSECE) to describe early care and education (ECE) centers that participate in two prominent publicly-funded ECE initiatives: Head Start and publicly-funded pre-kindergarten. Although a great deal is known about Head Start programs, and there are sources…

Heading Frequency Is More Strongly Related to Cognitive Performance Than Unintentional Head Impacts in Amateur Soccer Players.

Science.gov (United States)

Stewart, Walter F; Kim, Namhee; Ifrah, Chloe; Sliwinski, Martin; Zimmerman, Molly E; Kim, Mimi; Lipton, Richard B; Lipton, Michael L

2018-01-01

Compared to heading, unintentional head impacts (e.g., elbow to head, head to head, head to goalpost) in soccer are more strongly related to risk of moderate to very severe Central Nervous System (CNS) symptoms. But, most head impacts associated with CNS symptoms that occur in soccer are mild and are more strongly related to heading. We tested for a differential relation of heading and unintentional head impacts with neuropsychological (NP) test performance. Active adult amateur soccer players were recruited in New York City and the surrounding areas for this repeated measures longitudinal study of individuals who were enrolled if they had 5+ years of soccer play and were active playing soccer 6+ months/year. All participants completed a baseline validated questionnaire ("HeadCount-2w"), reporting 2-week recall of soccer activity, heading and unintentional head impacts. In addition, participants also completed NP tests of verbal learning, verbal memory, psychomotor speed, attention, and working memory. Most participants also completed one or more identical follow-up protocols (i.e., HeadCount-2w and NP tests) at 3- to 6-month intervals over a 2-year period. Repeated measures General Estimating Equations (GEE) linear models were used to determine if variation in NP tests at each visit was related to variation in either heading or unintentional head impacts in the 2-week period before testing. 308 players (78% male) completed 741 HeadCount-2w. Mean (median) heading/2-weeks was 50 (17) for men and 26 (7) for women. Heading was significantly associated with poorer performance on psychomotor speed ( p  impacts were not significantly associated with any NP test. Results did not differ after excluding 22 HeadCount-2w with reported concussive or borderline concussive symptoms. Poorer NP test performance was consistently related to frequent heading during soccer practice and competition in the 2 weeks before testing. In contrast, unintentional head impacts incurred

An Examination of the Contributions of Interactive Peer Play to Salient Classroom Competencies for Urban Head Start Children

Science.gov (United States)

Fantuzzo, John; Sekino, Yumiko; Cohen, Heather L.

2004-01-01

Relations between children's peer play competence and other relevant competencies were investigated using two samples of urban Head Start children. Dimensions of peer play were examined concurrently with emotion regulation, autonomy, and language. Children exhibiting high levels of peer play interaction were found to demonstrate more competent…

The Impact of the Chile Intervention on the Food Served in Head Start Centers in Rural New Mexico

Science.gov (United States)

Morshed, Alexandra B.; Davis, Sally M.; Keane, Patricia C.; Myers, Orrin B.; Mishra, Shiraz I.

2016-01-01

Background: The Child Health Initiative for Lifelong Eating and Exercise is a multicomponent obesity-prevention intervention, which was evaluated among Head Start (HS) centers in American Indian and predominantly Hispanic communities in rural New Mexico. This study examines the intervention's foodservice outcomes: fruits, vegetables, whole grains,…

A Music Program for Training Head Start Teachers Using a Sequential, Cognitive, Developmental Process with Pre-school Children.

Science.gov (United States)

Brodhecker, Shirley G.

This practicum report addresses the need to supply Head Start teachers with: (1) specific preschool music objectives; (2) a sequential preschool developmental program in music to match the child's cognitive level; (3) how to choose instructional material to encourage specific basic school readiness skills; and (4) workshops to accomplish these…

Predicting emergency diesel starting performance

International Nuclear Information System (INIS)

DeBey, T.M.

1989-01-01

The US Department of Energy effort to extend the operational lives of commercial nuclear power plants has examined methods for predicting the performance of specific equipment. This effort focuses on performance prediction as a means for reducing equipment surveillance, maintenance, and outages. Realizing these goals will result in nuclear plants that are more reliable, have lower maintenance costs, and have longer lives. This paper describes a monitoring system that has been developed to predict starting performance in emergency diesels. A prototype system has been built and tested on an engine at Sandia National Laboratories. 2 refs

Three Approaches to Preschoolers' Social and Emotional Competence: A Summary of Impact and Implementation Findings from Head Start CARES

Science.gov (United States)

MDRC, 2015

2015-01-01

This summary describes the Head Start CARES research project, which evaluated three classroom-based approaches to enhancing children's social-emotional development: (1) The Incredible Years Teacher Training Program; (2) Preschool PATHS (Promoting Alternative Thinking Strategies); and (3) Tools of the Mind--Play. The three social-emotional…

A media literacy nutrition education curriculum for head start parents about the effects of television advertising on their children's food requests.

Science.gov (United States)

Hindin, Toby J; Contento, Isobel R; Gussow, Joan Dye

2004-02-01

To evaluate whether a media literacy nutrition education curriculum about the effects of television advertising on children's food choices influenced the behavior, attitudes, and knowledge of Head Start parents. Participants were a convenience sample of 35 parents from Head Start programs. This study used a pretest-posttest, comparison condition-intervention condition design. The 35 parents participated in both a four-week food safety curriculum (to serve as an educational placebo, comparison condition) that was followed immediately by a four-week media literacy nutrition education curriculum (intervention condition). Evaluation measures included parents' understanding of the persuasive techniques of commercials; ability to distinguish between truths and claims in advertising; and outcome expectations, values, self-efficacy, and behaviors in relation to talking about television advertisements with children while co-viewing or in response to purchase requests in the grocery store. Paired t tests, analysis of covariance, and chi(2) analyses were used. The media literacy nutrition education intervention curriculum had significant effects in terms of Head Start parents' understanding television advertising (Padvertisements (PTV mediation behaviors (P<.001), and understanding of, and ability to read, food labels (P<.001). Results suggest that a media literacy nutrition education curriculum can be easily conducted by dietitians. Dietitians can modify the curriculum to teach parents how to critically analyze many other forms of media (supermarket magazines, brochures, newspapers, Web sites) that sell nutrition misinformation to the public.

Can Research Design Explain Variation in Head Start Research Results? A Meta-Analysis of Cognitive and Achievement Outcomes

Science.gov (United States)

Shager, Hilary M.; Schindler, Holly S.; Magnuson, Katherine A.; Duncan, Greg J.; Yoshikawa, Hirokazu; Hart, Cassandra M. D.

2013-01-01

This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

Bridging the digital divide by increasing computer and cancer literacy: community technology centers for head-start parents and families.

Science.gov (United States)

Salovey, Peter; Williams-Piehota, Pamela; Mowad, Linda; Moret, Marta Elisa; Edlund, Denielle; Andersen, Judith

2009-01-01

This article describes the establishment of two community technology centers affiliated with Head Start early childhood education programs focused especially on Latino and African American parents of children enrolled in Head Start. A 6-hour course concerned with computer and cancer literacy was presented to 120 parents and other community residents who earned a free, refurbished, Internet-ready computer after completing the program. Focus groups provided the basis for designing the structure and content of the course and modifying it during the project period. An outcomes-based assessment comparing program participants with 70 nonparticipants at baseline, immediately after the course ended, and 3 months later suggested that the program increased knowledge about computers and their use, knowledge about cancer and its prevention, and computer use including health information-seeking via the Internet. The creation of community computer technology centers requires the availability of secure space, capacity of a community partner to oversee project implementation, and resources of this partner to ensure sustainability beyond core funding.

Ethnic Group Differences in Early Head Start Parents Parenting Beliefs and Practices and Links to Children's Early Cognitive Development

Science.gov (United States)

Keels, Micere

2009-01-01

Data from the Early Head Start Research and Evaluation study were used to examine the extent to which several factors mediate between- and within-ethnic-group differences in parenting beliefs and behaviors, and children's early cognitive development (analysis sample of 1198 families). The findings indicate that Hispanic-, European-, and…

Is Dosage Important? Examining Head Start Preschoolers' Language and Literacy Learning after One versus Two Years of "ExCELL"

Science.gov (United States)

Hindman, Annemarie H.; Wasik, Barbara A.

2017-01-01

The current study examined whether Head Start children who experienced a high-quality preschool intervention, "Exceptional Coaching for Early Language and Literacy" ("ExCELL"), as three-year-olds began the subsequent pre-kindergarten (or four-year-old) year with stronger language and literacy skills than same-age peers who…

Development and field performance of indy race car head impact padding.

Science.gov (United States)

Melvin, J W; Bock, H; Anderson, K; Gideon, T

2001-11-01

The close-fitting cockpit of the modern Indy car single seat race car has the potential to provide a high level of head and neck impact protection in rear and side impacts. Crash investigation has shown that a wide variety of materials have been used as the padding for these cockpits and, as a result, produced varying outcomes in crashes. Additionally, these pads have not always been positioned for optimal performance. The purpose of this study was to investigate the head impact performance of a variety of energy-absorbing padding materials under impact conditions typical of Indy car rear impacts and to identify superior materials and methods of improving their performance as race car head pads. An extensive series of tests with the helmeted Hybrid III test dummy head and neck on an impact mini-sled was conducted to explore head padding concepts. Following this, a performance specification for a simplified impact test using a rigid headform that simulates the helmeted head was developed and recommendations for performance levels of head padding based on biomechanical data on helmeted head impacts were made. In 1997, during the time that the head pad research was being performed, the Indy Racing League introduced a new chassis specification for their cars. There were a number of rear- and side-impact crashes during that season that resulted in seven severe head injuries. Examples of the head padding in those cars were included in the experimental study. The results of the head pad research were used to specify new padding materials that met the new biomechanical criteria. The placement of the head pads was also changed for better location of the padding. These changes instituted in 1998 have reduced the number of head injuries in crashes similar to or more severe than those of 1997 and have resulted in only occasional moderate head injuries (concussions) in the 1998 and 1999 seasons.

Barriers and Motivators to Reducing Secondhand Smoke Exposure in African American Families of Head Start Children: A Qualitative Study

Science.gov (United States)

Hoehn, Jessica L.; Riekert, Kristin A.; Borrelli, Belinda; Rand, Cynthia S.; Eakin, Michelle N.

2016-01-01

Objective: To identify barriers and motivators for reducing secondhand smoke exposure (SHSe) for families of African-American, low-income, urban children. Method: Audiotaped intervention sessions of 52 African-American caregivers of Head Start children who reported being a smoker and/or had at least one smoker in the home were randomly sampled…

Administrative Task Performance by Heads of Senior High Schools ...

African Journals Online (AJOL)

This study aimed at examining the administrative task performance of heads of senior high schools (SHS) in Ghana from the organising perspective. The study hypothesized that there is no statistically significant difference in the compliance level of organising as an administrative task performance by heads in the rural and ...

Ethnic Variation in the Association between Family Structures and Practices on Child Outcomes at 36 Months: Results from Early Head Start

Science.gov (United States)

Iruka, Iheoma U.

2009-01-01

Research Findings: This study analyzed data from the Early Head Start Research and Evaluation Study (EHSRES) to examine whether the association between family structural characteristics (maternal education, number of parents, employment status, and number of children), parenting practices (sensitive and negative parenting, cognitively stimulating…

Using PANDA (Preventing the Abuse of Tobacco, Narcotics, Drugs, and Alcohol) in a Baltimore City Head Start Setting: A Preliminary Study.

Science.gov (United States)

Belcher, Harolyn M. E.; Lockhart, Paula J.; Perkins-Parks, Susan; McNally, Margaret

2000-01-01

Describes an evaluation of a substance abuse prevention curriculum, Preventing the Abuse of Tobacco, Narcotics, Drugs, and Alcohol (PANDA), taught to African American Head Start preschool students, examining changes in children's self-concept following participation. Overall, students demonstrated significantly improved self-concept, and PANDA…

An Unwilling Partnership With the Great Society Part I: Head Start and the Beginning of Change in the White Medical Community.

Science.gov (United States)

deShazo, Richard D; Minor, Wilson F Bill; Smith, Robert; Skipworth, Leigh Baldwin

2016-07-01

By 1965, the policies and programs of Lyndon B. Johnson's Great Society brought optimism to black physicians and a new wave of resistance against black civil rights advocates in the American South. The largest of the first Head Start programs, Child Development Group of Mississippi (CDGM), had its roots in Freedom Summer 1964 and the Medical Committee for Human Rights. Like other proposed programs with strong medical components, CDGM was caught in a legislative Bermuda triangle created by the powerful Mississippi congressional delegation to maintain white supremacy and plantation economics. Physician-led investigations exposed the extraordinary level of poor health among Mississippi's black children, supported Head Start as a remedy, and awakened the white medical establishment to health disparities of the Jim Crow period. It was also the beginning of positive change in the previously silent white medical community in the South and their support of civil justice in health. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

What is the Safest Sprint Starting Position for American Football Players?

Directory of Open Access Journals (Sweden)

Bruno Bonnechere, Benoit Beyer, Marcel Rooze, Jan Serge Van Sint

2014-06-01

Full Text Available The main objective of this study was to perform a biomechanical analysis of three different sprint start patterns to determine the safest position in term of neck injury and Sport-Related Concussion (SRC. The second objective was to collect data on the learning process effect between football players and non-players. Three different sprint initial positions adopted by football players were studied (i.e., 4-, 3- and 2-point positions. Twenty five young healthy males, including 12 football players, participated to this study. A stereophotogrammetric system (i.e., Vicon was used to record motion patterns and body segments positions. Various measurements related to head and trunk orientation, and player field-of-view were obtained (e.g., head height, trunk bending, time to reach upright position, head speed (vertical direction and body speed (horizontal direction. Learning process was found to have no influence on studied parameters. Head redress is also delayed when adopting a 4-point position leading to a reduce field-of-view during the start and increasing therefore the probability of collision. Concerning the three different positions, the 4-point position seems to be the more dangerous because leading to higher kinetic energy than the 2- and 3-point start positions. This study proposes a first biomechanical approach to understand risk/benefit balance for athletes for those three different start positions. Results suggested that the 4-point position is the most risky for football players.

Coaching and Demonstration of Evidence-Based Book-Reading Practices: Effects on Head Start Teachers' Literacy-Related Behaviors and Classroom Environment

Science.gov (United States)

Gettinger, Maribeth; Stoiber, Karen C.

2016-01-01

This study examined the effects of coaching with versus without demonstrations of evidence-based book-reading practices on teachers' use of strategies during independent book-reading periods. A total of 22 Head Start teachers were randomly assigned to one of two cohorts. One cohort (n = 12) participated in biweekly coaching sessions that included…

Validity Study of the "Preschool Language Scale-4" with English-Speaking Hispanic and European American Children in Head Start Programs

Science.gov (United States)

Qi, Cathy H.; Marley, Scott C.

2011-01-01

The purpose of the study was to examine the psychometric properties of the "Preschool Language Scale-4" (PLS-4) with a sample of English-speaking Hispanic and European American children who attended Head Start programs. Participants were 440 children between the ages of 3 and 5 years (52% male; 86% Hispanic and 14% European American).…

The prevalence of food insecurity and associated factors among households with children in Head Start programs in Houston, Texas and Birmingham, Alabama

Science.gov (United States)

This study measured food security and hunger of households enrolled in Head Start in Houston, Texas, and Birmingham, Alabama and assessed factors that could affect food security. Interviewers collected data from primary caregivers on demographic characteristics, dietary intake, and the six-item US f...

Evaluation of an oral health education session for Early Head Start home visitors.

Science.gov (United States)

Glatt, Kevin; Okunseri, Christopher; Flanagan, Diane; Simpson, Pippa; Cao, Yumei; Willis, Earnestine

2016-06-01

Home visiting programs promote the education and health of Early Head Start (EHS) children and pregnant women. However, EHS's oral health component is unevenly implemented. We conducted an educational intervention to improve oral health knowledge and motivational interviewing techniques among Wisconsin EHS home visitors. A questionnaire assessing oral health-related knowledge and confidence was administered to home visitors before and after an educational session. Changes between pre/post-responses were analyzed with McNemar's test and Wilcoxon Signed Rank test. After the intervention there were increases in both knowledge and confidence related to oral health communication. Knowledge increases were observed in such topics as fluoridation, dental caries, and caregivers' role in assisting and supervising children's tooth brushing. A brief educational intervention was associated with increased home visitor knowledge and confidence in communicating oral health messages to EHS caregivers and pregnant women. © 2016 American Association of Public Health Dentistry.

Ability to Categorize Food Predicts Hypothetical Food Choices in Head Start Preschoolers.

Science.gov (United States)

Nicholson, Jody S; Barton, Jennifer M; Simons, Ali L

2018-03-01

To investigate whether preschoolers are able to identify and categorize foods, and whether their ability to classify food as healthy predicts their hypothetical food choice. Structured interviews and body measurements with preschoolers, and teacher reports of classroom performance. Six Head Start centers in a large southeastern region. A total of 235 preschoolers (mean age [SD], 4.73 [0.63] years; 45.4% girls). Teachers implemented a nutrition education intervention across the 2014-2015 school year in which children were taught to identify and categorize food as sometimes (ie, unhealthy) and anytime (ie, healthy). Preschooler responses to a hypothetical snack naming, classifying, and selection scenario. Hierarchical regression analyses to examine predictors of child hypothetical food selection. While controlling for child characteristics and cognitive functioning, preschoolers who were better at categorizing food as healthy or unhealthy were more likely to say they would choose the healthy food. Low-contrast food pairs in which food had to be classified based on multiple dimensions were outside the cognitive abilities of the preschoolers. Nutrition interventions may be more effective in helping children make healthy food choices if developmental limitations in preschoolers' abilities to categorize food is addressed in their curriculum. Classification of food into evaluative categories is challenging for this age group. Categorizing on multiple dimensions is difficult, and dichotomous labeling of food as good or bad is not always accurate in directing children toward making food choices. Future research could evaluate further preschoolers' developmental potential for food categorization and nutrition decision making and consider factors that influence healthy food choices at both snack and mealtime. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

The development of a bilingual interactive video to improve physical activity and healthful eating in a head start population.

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Piziak, Veronica

2014-12-01

The prevalence of obesity in the Hispanic preschool population remains elevated, particularly among children in low income families below the poverty level. Obesity leads to the early onset of metabolic syndrome and Type 2 diabetes. The Head Start population of Texas is largely comprised of this high risk group. Their physical activity level is suboptimal in part due to lack of available outside play areas and time spent watching television and playing sedentary video games. Dietary intake is frequently high in sugar sweetened beverages and low in vegetables. The group is frequently bilingual with limited vocabulary and has not learned to read. Preserving their Mexican American culture is a concern. This article describes the development and assessment of a group of bilingual interactive video interventions to improve age appropriate physical activity while providing basic nutrition education focusing on increasing vegetable and water intake and decreasing sugar sweetened beverages. Suggestions for development and assessment of content were provided by focus groups of Head Start teachers, managers and dietitians in the Texas counties of Bastrop, Hidalgo and McLennon. A demonstration of the videos was conducted in Bastrop County. Teachers, students and managers felt that the videos provided excellent information, improved exercise participation and engaged the children.

The Development of a Bilingual Interactive Video to Improve Physical Activity and Healthful Eating in a Head Start Population

Directory of Open Access Journals (Sweden)

Veronica Piziak

2014-12-01

Full Text Available The prevalence of obesity in the Hispanic preschool population remains elevated, particularly among children in low income families below the poverty level. Obesity leads to the early onset of metabolic syndrome and Type 2 diabetes. The Head Start population of Texas is largely comprised of this high risk group. Their physical activity level is suboptimal in part due to lack of available outside play areas and time spent watching television and playing sedentary video games. Dietary intake is frequently high in sugar sweetened beverages and low in vegetables. The group is frequently bilingual with limited vocabulary and has not learned to read. Preserving their Mexican American culture is a concern. This article describes the development and assessment of a group of bilingual interactive video interventions to improve age appropriate physical activity while providing basic nutrition education focusing on increasing vegetable and water intake and decreasing sugar sweetened beverages. Suggestions for development and assessment of content were provided by focus groups of Head Start teachers, managers and dietitians in the Texas counties of Bastrop, Hidalgo and McLennon. A demonstration of the videos was conducted in Bastrop County. Teachers, students and managers felt that the videos provided excellent information, improved exercise participation and engaged the children.

Reliving the History of Compensatory Education: Policy Choices, Bureaucracy, and the Politicized Role of Science in the Evolution of Head Start

Science.gov (United States)

Beatty, Barbara; Zigler, Edward

2012-01-01

In this article, Edward Zigler, interviewed by Barbara Beatty, talks about a turning point in the history of Head Start that reveals how policy choices, bureaucracy, and science came together when he was told to phase out the program in 1970. New to Washington, Zigler learned that President Richard M. Nixon's domestic policy advisor Daniel Patrick…

Are the new starting block facilities beneficial for backstroke start performance?

Science.gov (United States)

de Jesus, Karla; de Jesus, Kelly; Abraldes, J Arturo; Medeiros, Alexandre Igor Araripe; Fernandes, Ricardo J; Vilas-Boas, João Paulo

2016-01-01

We aimed to analyse the handgrip positioning and the wedge effects on the backstroke start performance and technique. Ten swimmers completed randomly eight 15 m backstroke starts (four with hands on highest horizontal and four on vertical handgrip) performed with and without wedge. One surface and one underwater camera recorded kinematic data. Standardised mean difference (SMD) and 95% confidence intervals (CI) were used. Handgrip positioning did not affect kinematics with and without wedge use. Handgrips horizontally positioned and feet over wedge displayed greater knee angular velocity than without it (SMD = -0.82; 95% CI: -1.56, -0.08). Hands vertically positioned and feet over wedge presented greater take-off angle (SMD = -0.81; 95% CI: -1.55, -0.07), centre of mass (CM) vertical positioning at first water contact (SMD = -0.97; 95% CI: -1.87, -0.07) and CM vertical velocity at CM immersion (SMD = 1.03; 95% CI: 0.08, 1.98) when comparing without wedge use. Swimmers extended the hip previous to the knee and ankle joints, except for the variant with hands vertically positioned without wedge (SMD = 0.75; 95% CI: -0.03, 1.53). Swimmers should preserve biomechanical advantages achieved during flight with variant with hands vertically positioned and wedge throughout entry and underwater phase.

Effects of Residential Instability on Head Start Children and Their Relationships with Older Siblings: Influences of Child Emotionality and Conflict between Family Members.

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Stoneman, Zolinda; Brody, Gene H.; Churchill, Susan L.; Winn, Laura L.

1999-01-01

Examined influence of residential dislocations on child behavior problems, depression, peer competence, cognitive competence, and quality of sibling relationships among Head Start children and their older siblings. Found that child emotionality moderated the effects of residential mobility. Caregiver conflict was a less powerful moderator.…

Promoting Children's Social-Emotional Skills in Preschool Can Enhance Academic and Behavioral Functioning in Kindergarten: Findings from Head Start REDI.

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Nix, Robert L; Bierman, Karen L; Domitrovich, Celene E; Gill, Sukhdeep

2013-01-01

This study examined processes of change associated with the positive preschool and kindergarten outcomes of children who received the Head Start REDI intervention, compared to "usual practice" Head Start. In a large-scale randomized-controlled trial (N = 356 children, 42% African American or Latino, all from low-income families), this study tests the logic model that improving preschool social-emotional skills (e.g., emotion understanding, social problem solving, and positive social behavior) as well as language/emergent literacy skills will promote cross-domain academic and behavioral adjustment after children transition into kindergarten. Validating this logic model, the present study finds that intervention effects on three important kindergarten outcomes (e.g., reading achievement, learning engagement, and positive social behavior) were mediated by preschool gains in the proximal social-emotional and language/emergent literacy skills targeted by the REDI intervention. Importantly, preschool gains in social-emotional skills made unique contributions to kindergarten outcomes in reading achievement and learning engagement, even after accounting for the concurrent preschool gains in vocabulary and emergent literacy skills. These findings highlight the importance of fostering at-risk children's social-emotional skills during preschool as a means of promoting school readiness. The REDI (Research-Based, Developmentally-Informed) enrichment intervention was designed to complement and strengthen the impact of existing Head Start programs in the dual domains of language/emergent literacy skills and social-emotional competencies. REDI was one of several projects funded by the Interagency School Readiness Consortium, a partnership of four federal agencies (the National Institute of Child Health and Human Development, the Administration for Children and Families, the Assistant Secretary for Planning and Evaluation in the Department of Health and Human Services, and the

Head Start’s Impact is Contingent on Alternative Type of Care in Comparison Group

Science.gov (United States)

Brooks-Gunn, Jeanne; Waldfogel, Jane

2014-01-01

Using data (n = 3,790 with 2,119 in the 3-year-old cohort and 1,671 in the 4-year-old cohort) from 353 Head Start centers in the Head Start Impact Study, the only large-scale randomized experiment in Head Start history, this paper examined the impact of Head Start on children’s cognitive and parent-reported social-behavioral outcomes through first grade contingent on the child care arrangements used by children who were randomly assigned to the control group (i.e., parental care, relative/non-relative care, another Head Start program, or other center-based care). A principal score matching approach was adopted to identify children assigned to Head Start who were similar to children in the control group with a specific care arrangement. Overall, the results showed that the effects of Head Start varied substantially contingent on the alternative child care arrangements. Compared to children in parental care and relative/non-relative care, Head Start participants generally had better cognitive and parent-reported behavioral development, with some benefits of Head Start persisting through first grade; in contrast, few differences were found between Head Start and other center-based care. The results have implications regarding the children for whom Head Start is most beneficial as well as how well Head Start compares to other center-based programs. PMID:25329552

Effect of the Children's Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial.

Science.gov (United States)

Robinson, Leah E; Palmer, Kara K; Bub, Kristen L

2016-01-01

Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children's Health Activity Motor Program, CHAMP) that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 ± 6.5 months; 49.5% males) were randomly assigned to a treatment (n = 68) or control (n = 45) program. CHAMP participants engaged in 15, 40-min sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development-2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time × treatment interaction (p motor skills, post hoc comparisons found that all children improved their motor skills (p skills associated with healthy development in children (i.e., motor skills and self-regulation). This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool age children and significantly improved motor skills while participating in outdoor recess was not effective. CHAMP could help contribute to children's learning-related skills and physical development and subsequently to their academic success.

Evaluating Two Oral Health Video Interventions with Early Head Start Families

Directory of Open Access Journals (Sweden)

Lynn B. Wilson

2013-01-01

Full Text Available Poor oral health in early childhood can have long-term consequences, and parents often are unaware of the importance of preventive measures for infants and toddlers. Children in rural, low-income families suffer disproportionately from the effects of poor oral health. Participants were 91 parents of infants and toddlers enrolled in Early Head Start (EHS living in rural Hawai'i, USA. In this quasi-experimental design, EHS home visitors were assigned to use either a didactic or family-centered video with parents they served. Home visitors reviewed short segments of the assigned videos with parents over an eight-week period. Both groups showed significant prepost gains on knowledge and attitudes/behaviors relating to early oral health as well as self-reported changes in family oral health routines at a six-week followup. Controlling for pretest levels, parents in the family-centered video group showed larger changes in attitudes/behaviors at posttest and a higher number of positive changes in family oral health routines at followup. Results suggest that family-centered educational videos are a promising method for providing anticipatory guidance to parents regarding early childhood oral health. Furthermore, establishing partnerships between dental care, early childhood education, and maternal health systems offers a model that broadens potential reach with minimal cost.

Correlating cumulative sub-concussive head impacts in football with player performance - biomed 2009.

Science.gov (United States)

Rowson, Steven; Goforth, Mike W; Dietter, Dave; Brolinson, P Gunnar; Duma, Stefanan M

2009-01-01

The objective of this study was to investigate the effect of cumulative sub-concussive head impacts on football player performance. The helmets of three Virginia Tech football players were instrumented with a six accelerometer sensor capable of measuring head acceleration. Helmets were instrumented for every game during the 2006 and 2007 football seasons. Each time the head was impacted during a game, the sensor recorded the impact and wirelessly transmitted the data to a sideline computer. Furthermore, the coaching staff at Virginia Tech reviewed post-game film and evaluated each player's performance based on strict criteria. Players were awarded positive points for good plays and negative points for bad plays. Their performance scores were then normalized to a per play basis. Correlations of player performance with cumulative peak linear acceleration and cumulative head injury criterion (HIC) were evaluated. No consistent head acceleration-based measure showed a strong correlation with significance. In addition, relationship trends varied on a position basis. There are many factors other than head impacts that can affect a player's performance and more research is needed to further quantify such effects.

Head Start Service Guide for Children and Families with HIV or AIDS = Guia de Servicios para Ninos con V.I.H. Positivo y con Sindrome de Inmunodeficiencia Adquirida (S.I.D.A.) y sus Familias.

Science.gov (United States)

Puerto Rico Commonwealth Office of Children's Services and Community Development, Old San Juan.

This document provides guidelines and procedures, in Spanish and English, for Head Start teachers in taking care of children with AIDS, or children who are HIV positive, and their families. The goal of the guide is to maximize participation of infected children in the Head Start program. The guide presents activities in three main stages:…

Effects of Home and School Computer Use on School Readiness and Cognitive Development among Head Start Children: A Randomized Controlled Pilot Trial

Science.gov (United States)

Li, Xiaoming; Atkins, Melissa S.; Stanton, Bonita

2006-01-01

Data from 122 Head Start children were analyzed to examine the impact of computer use on school readiness and psychomotor skills. Children in the experimental group were given the opportunity to work on a computer for 15-20 minutes per day with their choice of developmentally appropriate educational software, while the control group received a…

Mechanical analysis of ceramic head for modular hip prosthesis

International Nuclear Information System (INIS)

Ravagli, E.

1995-03-01

A study, performed with the department of orthopaedics of the Rome Catholic University, has found out the two possible parameters mainly responsible for head breaking, i. e. errors in conical mating between head and stem, and cracks in the heads. This study has been continued in the frame of the STRIDE-CETMA project, aimed at founding and developing a centre for technologically advanced materials in Brindisi Technology Park (Italy). This report starts a systematic mechanical analysis of the above mentioned head, with the purpose of characterizing it exhaustively. The evaluations made lead to the conclusion that in nomimal conditions, the head is largely overdimensioned, taking into account the maximum load applied to the prosthesis

Relations among the Home Language and Literacy Environment and Children's Language Abilities: A Study of Head Start Dual Language Learners and Their Mothers

Science.gov (United States)

Lewis, Kandia; Sandilos, Lia E.; Hammer, Carol Scheffner; Sawyer, Brook E.; Méndez, Lucía I.

2016-01-01

Research Findings: This study explored the relations between Spanish-English dual language learner (DLL) children's home language and literacy experiences and their expressive vocabulary and oral comprehension abilities in Spanish and in English. Data from Spanish-English mothers of 93 preschool-age Head Start children who resided in central…

The effect of social geographic factors on the untreated tooth decay among head start children.

Science.gov (United States)

Heima, Masahiro; Ferretti, Margaret; Qureshi, Mehveen; Ferretti, Gerald

2017-10-01

Disparities among untreated dental caries exist for children from low-income families in the United States. Understanding of the mechanism of the disparities is required to reduce it and social geographic factors are one of the important influences. Although the effect of fluoridated water has been well reported, studies of other sociogeograpic factors, such as the density of available dentists, are still very limited. The objective of this study is to explore the effect of sociogeographic factors on the number of primary teeth with untreated dental caries among children from low-income families who are enrolled in Head Start programs throughout Northeast Ohio of the United States. This was a cross-sectional chart review study. Three hundred-eighty-eight charts were reviewed, and the number of primary teeth with untreated dental caries (dt) and the children's addresses were retrieved. The sociogeographic variables, including fluoridated water availability and the density of available dentists who accept a government-supported insurance (Medicaid dentists), were collected. The mean (standard deviation) of children's age was 3.51 (1.14) years with a range of 7 months to 5 years. A negative binomial regression model analysis, which used dt as a dependent variable and children's characteristic factors (i.e. age, gender, insurance type, and total number of primary teeth) and sociogeographic factors (i.e. Population, total number of Medicaid dentists, density of Medicaid dentist, and Fluoride water availability) of cities, as independent variables, demonstrated that only the density of Medicaid dentist in the sociogeographic factors indicated a significant effect (Estimated ß-Coefficients (Standard Errors)=-0.003 (0.002), p =0.030). This study demonstrated a significant negative association between the density of available dentists and untreated dental caries among children from low-income families in Head Start programs in Northeast Ohio. Increasing available dentists

Single phase induction motor with starting performance

Energy Technology Data Exchange (ETDEWEB)

Popescu, M.; Demeter, E. [Research Institute for Electrical Machines, ICPE-ME, Bucharest (Romania); Navrapescu, V. [University `Politehnica` Bucharest, Electrical Engineering Faculty Splaiul Independentei, Bucharest (Romania)

1997-12-31

The paper presents problems related to a special type of single phase induction motor. The main novelty consists in the use of a conducting (aluminium casted) shell distributed on the periferic region of the rotor. As a result the starting performance, as well as the rated ones, is much improved in comparison with the conventional construction. (orig.) 4 refs.

A Resource Guide for Head Start Programs: Moving beyond a Culture of Compliance to a Culture of Continuous Improvement. OPRE Report 2015-02

Science.gov (United States)

Derrick-Mills, Teresa; Winkler, Mary K.; Healy, Olivia; Greenberg, Erica

2015-01-01

Head Start has long focused on assessing and improving program quality to ensure that the children served receive the best possible preparation for school and life. Most research has been focused inside the classroom--the classroom environment, teacher qualifications, and teacher interactions. Of course, the classroom is important because that is…

Observed Emotional and Behavioral Indicators of Motivation Predict School Readiness in Head Start Graduates

Science.gov (United States)

Berhenke, Amanda; Miller, Alison L.; Brown, Eleanor; Seifer, Ronald; Dickstein, Susan

2011-01-01

Emotions and behaviors observed during challenging tasks are hypothesized to be valuable indicators of young children's motivation, the assessment of which may be particularly important for children at risk for school failure. The current study demonstrated reliability and concurrent validity of a new observational assessment of motivation in young children. Head Start graduates completed challenging puzzle and trivia tasks during their kindergarten year. Children's emotion expression and task engagement were assessed based on their observed facial and verbal expressions and behavioral cues. Hierarchical regression analyses revealed that observed persistence and shame predicted teacher ratings of children's academic achievement, whereas interest, anxiety, pride, shame, and persistence predicted children's social skills and learning-related behaviors. Children's emotional and behavioral responses to challenge thus appeared to be important indicators of school success. Observation of such responses may be a useful and valid alternative to self-report measures of motivation at this age. PMID:21949599

Joint kinetic determinants of starting block performance in athletic sprinting.

Science.gov (United States)

Brazil, Adam; Exell, Timothy; Wilson, Cassie; Willwacher, Steffen; Bezodis, Ian N; Irwin, Gareth

2018-07-01

The aim of this study was to explore the relationships between lower limb joint kinetics, external force production and starting block performance (normalised average horizontal power, NAHP). Seventeen male sprinters (100 m PB, 10.67 ± 0.32 s) performed maximal block starts from instrumented starting blocks (1000 Hz) whilst 3D kinematics (250 Hz) were also recorded during the block phase. Ankle, knee and hip resultant joint moment and power were calculated at the rear and front leg using inverse dynamics. Average horizontal force applied to the front (r = 0.46) and rear (r = 0.44) block explained 86% of the variance in NAHP. At the joint level, many "very likely" to "almost certain" relationships (r = 0.57 to 0.83) were found between joint kinetic data and the magnitude of horizontal force applied to each block although stepwise multiple regression revealed that 55% of the variance in NAHP was accounted for by rear ankle moment, front hip moment and front knee power. The current study provides novel insight into starting block performance and the relationships between lower limb joint kinetic and external kinetic data that can help inform physical and technical training practices for this skill.

Effect of the Children’s Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial

Science.gov (United States)

Robinson, Leah E.; Palmer, Kara K.; Bub, Kristen L.

2016-01-01

Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children’s Health Activity Motor Program, CHAMP) that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 ± 6.5 months; 49.5% males) were randomly assigned to a treatment (n = 68) or control (n = 45) program. CHAMP participants engaged in 15, 40-min sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development-2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time × treatment interaction (p motor skills, post hoc comparisons found that all children improved their motor skills (p skills associated with healthy development in children (i.e., motor skills and self-regulation). This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool age children and significantly improved motor skills while participating in outdoor recess was not effective. CHAMP could help contribute to children’s learning-related skills and physical development and subsequently to their academic success. PMID:27660751

Effectiveness of differing levels of support for family meals on obesity prevention among head start preschoolers: the simply dinner study

Directory of Open Access Journals (Sweden)

Holly E. Brophy-Herb

2017-02-01

Full Text Available Abstract Background Despite slight decreases in obesity prevalence in children, nearly 25% of preschool-aged children are overweight or obese. Most interventions focused on promoting family meals as an obesity-prevention strategy target meal planning skills, knowledge and modeling of healthy eating without addressing the practical resources that enable implementation of family meals. There is a striking lack of evidence about what level of resources low-income parents need to implement family meals. This study will identify resources most effective in promoting family meals and, subsequently, test associations among the frequency of family meals, dietary quality and children’s adiposity indices among children enrolled in Head Start. Methods The Multiphase Optimization Strategy, employed in this study, is a cutting-edge approach to maximizing resources in behavioral interventions by identifying the most effective intervention components. We are currently testing the main, additive and interactive effects of 6 intervention components, thought to support family meals, on family meal frequency and dietary quality (Primary Outcomes as compared to Usual Head Start Exposure in a Screening Phase (N = 512 low-income families. Components yielding the most robust effects will be bundled and evaluated in a two-group randomized controlled trial (intervention and Usual Head Start Exposure in the Confirming Phase (N = 250, testing the effects of the bundled intervention on children’s adiposity indices (Primary Outcomes; body mass index and skinfolds. The current intervention components include: (1 home delivery of pre-made healthy family meals; (2 home delivery of healthy meal ingredients; (3 community kitchens in which parents make healthy meals to cook at home; (4 healthy eating classes; (5 cooking demonstrations; and (6 cookware/flatware delivery. Secondary outcomes include cooking self-efficacy and family mealtime barriers. Moderators of the

Effectiveness of differing levels of support for family meals on obesity prevention among head start preschoolers: the simply dinner study.

Science.gov (United States)

Brophy-Herb, Holly E; Horodynski, Mildred; Contreras, Dawn; Kerver, Jean; Kaciroti, Niko; Stein, Mara; Lee, Hannah Jong; Motz, Brittany; Hebert, Sheilah; Prine, Erika; Gardiner, Candace; Van Egeren, Laurie A; Lumeng, Julie C

2017-02-10

Despite slight decreases in obesity prevalence in children, nearly 25% of preschool-aged children are overweight or obese. Most interventions focused on promoting family meals as an obesity-prevention strategy target meal planning skills, knowledge and modeling of healthy eating without addressing the practical resources that enable implementation of family meals. There is a striking lack of evidence about what level of resources low-income parents need to implement family meals. This study will identify resources most effective in promoting family meals and, subsequently, test associations among the frequency of family meals, dietary quality and children's adiposity indices among children enrolled in Head Start. The Multiphase Optimization Strategy, employed in this study, is a cutting-edge approach to maximizing resources in behavioral interventions by identifying the most effective intervention components. We are currently testing the main, additive and interactive effects of 6 intervention components, thought to support family meals, on family meal frequency and dietary quality (Primary Outcomes) as compared to Usual Head Start Exposure in a Screening Phase (N = 512 low-income families). Components yielding the most robust effects will be bundled and evaluated in a two-group randomized controlled trial (intervention and Usual Head Start Exposure) in the Confirming Phase (N = 250), testing the effects of the bundled intervention on children's adiposity indices (Primary Outcomes; body mass index and skinfolds). The current intervention components include: (1) home delivery of pre-made healthy family meals; (2) home delivery of healthy meal ingredients; (3) community kitchens in which parents make healthy meals to cook at home; (4) healthy eating classes; (5) cooking demonstrations; and (6) cookware/flatware delivery. Secondary outcomes include cooking self-efficacy and family mealtime barriers. Moderators of the intervention include family functioning and

IMMEDIATE EFFECTS OF DEEP TRUNK MUSCLE TRAINING ON SWIMMING START PERFORMANCE.

Science.gov (United States)

Iizuka, Satoshi; Imai, Atsushi; Koizumi, Keisuke; Okuno, Keisuke; Kaneoka, Koji

2016-12-01

In recent years, deep trunk muscle training has been adopted in various sports, including swimming. This is performed both in everyday training and as part of the warm-up routine before competitive races. It is suggested that trunk stabilization exercises are effective in preventing injury, and aid in improving performance. However, conclusive evidence of the same is yet to be obtained. The time of start phase of swimming is a factor that can significantly influence competition performance in a swimming race. If trunk stabilization exercises can provide instantaneous trunk stability, it is expected that they will lead to performance improvements in the start phase of swimming. The purpose of this study was to investigate the immediate effect of trunk stabilization exercises on the start phase in swimming. Intervention study. Nine elite male swimmers (mean age 20.2 ± 1.0 years; height 174.4 ± 3.5 cm; weight 68.9 ± 4.1 kg) performed the swimming start movement. The measurement variables studied included flying distance, and the time and velocity of subjects at hands' entry and on reaching five meters. Measurements were taken in trials immediately before and after the trunk stabilization exercises. A comparison between pre- and post-exercise measurements was assessed. The time to reach five meters (T 5m ) decreased significantly after trunk stabilization exercises, by 0.019 s (p = 0.02). Velocity at entry (V entry ) did not demonstrate significant change, while velocity at five meters (V 5m ) increased significantly after the exercises (p = 0.023). In addition, the speed reduction rate calculated from V entry and V 5m significantly decreased by 5.17% after the intervention (p = 0.036). Trunk stabilization exercises may help reduce the time from start to five meters in the start phase in swimming. The results support the hypothesis that these exercises may improve swimming performance. Level 3b.

Exploring Daily Physical Activity and Nutrition Patterns in Early Learning Settings: Snapshots of Young Children in Head Start, Primary, and After-School Settings

Science.gov (United States)

Stegelin, Dolores A.; Anderson, Denise; Kemper, Karen; Wagner, Jennifer; Evans, Katharine

2014-01-01

The purpose of this research project was to gain a greater understanding of daily routines of 4-7 year olds regarding physical activity and nutrition practices in typical early learning environments. The settings selected for this observational study included Head Start, primary, and after-school learning environments in a city in the southeast.…

LEARNING-RELATED SOCIAL SKILLS AS A MEDIATOR BETWEEN TEACHER INSTRUCTION AND CHILD ACHIEVEMENT IN HEAD START

Science.gov (United States)

Gershoff, Elizabeth

2015-01-01

Using a subsample of the Family and Child Experiences Survey (FACES) 2006, this study examined the associations between the amount of teacher instruction in 292 Head Start classrooms with changes in young children’s (n = 936) early academic achievement and learning-related social skills from ages 3 to 5. In general, during the early years, children exhibited relatively stable academic and learning-related social skills. Although the amount of teacher instruction did not predict children’s short-term academic growth directly, it did predict it indirectly through improvements in learning-related social skills, with benefits lasting through the end of kindergarten. These findings demonstrate that gains in children’s learning-related social skills may be necessary before academic gains can be realized. PMID:26692657

Giving Latino Children a Stronger Start. New Journalism on Latino Children

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Rivera, Carla

2009-01-01

Early Head Start serves newborns through toddlers. It is an offshoot of Head Start, the 44-year-old federal program for low-income children ages 3 through 5. Social scientists studying brain development and emotional growth increasingly identify early education as critical to preparing children for kindergarten. As well, researchers have linked it…

Optimization Design and Performance Analysis of a Pit Turbine with Ultralow Head

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Chunxia Yang

2014-04-01

Full Text Available A developed pit turbine with ultralow head was optimization designed under the design head of about 2 meters to achieve the goal of improving the turbine unit's efficiency. At the same time, the turbine's synthetic characteristic curve was drawn to predict the turbine's overall performance. Navier-Stokes equations and SIMPLEC algorithm were used for pit turbine's whole flow passage numerical simulation of the 3D, steady, incompressible, turbulent flow field. Through the CFD numerical simulation, the influence to ultralow head turbine's performance was analyzed by runner blade's different setting angles and guide vane's different axes. Considering the hydraulic performance of various methods, the best blade's setting angle and guide vane's axis were chosen. The results show that, the turbine unit has the best performance on efficiency, hydraulic loss, and so forth, with the blade's setting angle 23° and the angle 72° between the guide vane and the centerline of unit, meeting the power station's design requirements. The development pit turbine with ultralow head shows the highest efficiency of 87.6% under condition of design head of 2.1 meters and design discharge of 10 m3/s. The energy performance of pit turbine with ultralow head was researched by the model test of GD-WS-35 turbine. The model turbine's characteristic curve was drawn. The model turbine's high efficiency area is wide and the efficiency changes mildly. The numerical simulation results are essentially consistent with the model test results, while the former one is slightly higher than the latter one. The error range is ±3%.

Start-Up Size Strategy and Risk Management: Impact on New Venture Performance

OpenAIRE

André van Stel; Andrew Burke; José Maria Millán; Concepcion Roman

2013-01-01

Start-up size is a key strategic decision for entrepreneurs. Should entrepreneurs start up close to minimum efficient scale or should they take less risks and start-up on a smaller scale? Previously, this strategic decision appeared to be one of simply making a choice between a higher risk/reward larger start-up versus a lower risk/reward smaller scale start-up. However, recent research on the relationship between risk management and performance (Burke, 2009) indicates that in situations of g...

Empowering Head Start African American and Latino Families: Promoting Strengths-Based Parenting Characteristics through Child Parent Relationship Training--An Evidence-Based Group Parenting Program

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Sheely-Moore, Angela I.; Ceballos, Peggy L.

2011-01-01

With the tendency of low-income African American and Latino children identified at-risk for school readiness and school success compared to their early-childhood counterparts, Head Start personnel are challenged to examine the role of family strengths in the promotion of academic success for these populations. This article provides a rationale for…

Jump2Health Website™ for Head Start parents to promote a healthy home environment: Results from formative research.

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Gurajada, Navya; Reed, Debra B; Taylor, Ashlee L

2017-12-13

Background: In US, approximately 23% of children between the ages of 2-5 years are overweight or obese. Parents need access to information to create healthy home environments for obesity prevention, yet participation for in-person education programs is challenging. Web-based interventions are promising educational tools due to 24/7 availability. However, information is limited on their development and evaluation. Design and Methods: This study reports on a rigorous development process that included six focus group discussions (FGD) with stakeholders (three FGD each with parents and teachers) to assess education needs and inform the development of the Jump2Health Website ™ by a multidisciplinary team. After development, the Website was evaluated by telephone interviews with stakeholders (five parents and six teachers) and reviewed by an expert panel of five Registered Dietitians. Results: Twenty Head Start parents and 22 Head Start teachers participated in the FGD. To address the needs identified by these stakeholders, the Website was designed to include components that were enabling and motivating, such as descriptions of health benefits by achieving the desired behaviours, short videos on easy meal preparation, and tip sheets on how to achieve healthy behaviours in easy, economical ways. Stakeholder evaluation of the Website indicated that the information was helpful, easy to use, and would be beneficial for parents. Conclusions: The development of Jump2Health Website ™ was strengthened by FGD with stakeholders that assessed educational needs. Interviews with stakeholders and an expert panel review showed that the Website may be an effective educational method to teach parents about healthy behaviours related to obesity prevention.

Jump2Health Website™ for Head Start parents to promote a healthy home environment: Results from formative research

Directory of Open Access Journals (Sweden)

Navya Gurajada

2017-12-01

Full Text Available Background: In US, approximately 23% of children between the ages of 2-5 years are overweight or obese. Parents need access to information to create healthy home environments for obesity prevention, yet participation for in-person education programs is challenging. Web-based interventions are promising educational tools due to 24/7 availability. However, information is limited on their development and evaluation. Design and Methods: This study reports on a rigorous development process that included six focus group discussions (FGD with stakeholders (three FGD each with parents and teachers to assess education needs and inform the development of the Jump2Health Website™ by a multidisciplinary team. After development, the Website was evaluated by telephone interviews with stakeholders (five parents and six teachers and reviewed by an expert panel of five Registered Dietitians. Results: Twenty Head Start parents and 22 Head Start teachers participated in the FGD. To address the needs identified by these stakeholders, the Website was designed to include components that were enabling and motivating, such as descriptions of health benefits by achieving the desired behaviours, short videos on easy meal preparation, and tip sheets on how to achieve healthy behaviours in easy, economical ways. Stakeholder evaluation of the Website indicated that the information was helpful, easy to use, and would be beneficial for parents. Conclusions: The development of Jump2Health Website™ was strengthened by FGD with stakeholders that assessed educational needs. Interviews with stakeholders and an expert panel review showed that the Website may be an effective educational method to teach parents about healthy behaviours related to obesity prevention.

Relationship between different push-off variables and start performance in experienced swimmers.

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García-Ramos, Amador; Feriche, Belén; de la Fuente, Blanca; Argüelles-Cienfuegos, Javier; Strojnik, Vojko; Strumbelj, Boro; Štirn, Igor

2015-01-01

The objective of this study was to determine the relationship between different variables measured with a force plate during the swimming start push-off phase and start performance presented by times to 5, 10 and 15 m. Twenty-one women from the Slovenian national swimming team performed two different swim starts (freestyle and undulatory) on a portable force plate to a distance further than 15 m. Correlations between push-off variables and times to 5, 10 and 15 m were quantified through Pearson's product-moment correlation coefficient (r). The variables that significantly correlated (p  .05). Based on the results of this study, we can conclude that horizontal take-off velocity and average horizontal acceleration (calculated as the average horizontal force divided by swimmer's body mass) are the variables most related to swimming start performance in experienced swimmers, and therefore could be the preferred measures to monitor swimmers' efficiency during the push-off phase.

Head Start Family and Child Experiences Survey (FACES) 1997 Cohort

Data.gov (United States)

U.S. Department of Health & Human Services — Descriptive, longitudinal study including direct assessments, classroom observation, parent and teacher interviews, for a nationally represenative sample of Head...

Head Start Family and Child Experiences Survey (FACES) 2000 Cohort

Data.gov (United States)

U.S. Department of Health & Human Services — Descriptive, longitudinal study including direct assessments, classroom observation, parent and teacher interviews, for a nationally represenative sample of Head...

Head Start Family and Child Experiences Survey (FACES) 2003 Cohort

Data.gov (United States)

U.S. Department of Health & Human Services — Descriptive, longitudinal study including direct assessments, classroom observation, parent and teacher interviews, for a nationally represenative sample of Head...

Head Start Family and Child Experiences Survey (FACES) 2006 Cohort

Data.gov (United States)

U.S. Department of Health & Human Services — Descriptive, longitudinal study including direct assessments, classroom observation, parent and teacher interviews, for a nationally represenative sample of Head...

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.

Child Behavior Problems, Teacher Executive Functions, and Teacher Stress in Head Start Classrooms.

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Friedman-Krauss, Allison H; Raver, C Cybele; Neuspiel, Juliana M; Kinsel, John

2014-01-01

The current article explores the relationship between teachers' perceptions of child behavior problems and preschool teacher job stress, as well as the possibility that teachers' executive functions moderate this relationship. Data came from 69 preschool teachers in 31 early childhood classrooms in 4 Head Start centers and were collected using Web-based surveys and Web-based direct assessment tasks. Multilevel models revealed that higher levels of teachers' perceptions of child behavior problems were associated with higher levels of teacher job stress and that higher teacher executive function skills were related to lower job stress. However, findings did not yield evidence for teacher executive functions as a statistical moderator. Many early childhood teachers do not receive sufficient training for handling children's challenging behaviors. Child behavior problems increase a teacher's workload and consequently may contribute to feelings of stress. However, teachers' executive function abilities may enable them to use effective, cognitive-based behavior management and instructional strategies during interactions with students, which may reduce stress. Providing teachers with training on managing challenging behaviors and enhancing executive functions may reduce their stress and facilitate their use of effective classroom practices, which is important for children's school readiness skills and teachers' health.

The influence of gate start position on physical performance and anxiety perception in expert BMX athletes.

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Di Rienzo, Franck; Martinent, Guillaume; Levêque, Lucie; MacIntyre, Tadhg; Collet, Christian; Guillot, Aymeric

2018-02-01

The critical importance of the start phase in bicycle motocross (BMX) racing is increasingly acknowledged. Past experiments underlined that the internal lane of the starting gate provides a strong positional advantage. However, how lane position affects start performance and cognitive and somatic state anxiety remains unexplored. We examined the start performance and anxiety responses of youth national-level BMX riders in both experimental and ecological contexts. We used contextualization motor imagery routines to evaluate start performance and state anxiety from the internal and external lanes. Cycle ergometer measures revealed a better start performance from the external lane, but we did not record any lane effect on actual gate start times. Both somatic and cognitive anxiety scores were higher before racing from the internal compared to the external lane. Finally, state anxiety (i.e., somatic anxiety, worry and concentration disruptions) negatively predicted the start performance. Present findings provide original insights on psychological factors involved in BMX start performance, and might contribute to fruitful coping interventions and training programmes in sports overlapping the framework of "handicap races" taking the specific form of positional advantages/disadvantages at the start (e.g., ski/snowboard cross, athletics, swimming, motorsports, etc.).

The Effects of Head Start on Children's Kindergarten Retention, Reading and Math Achievement in Fall Kindergarten--An Application of Propensity Score Method and Sensitivity Analysis

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Dong, Nianbo

2009-01-01

Using data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), this paper applied optimal propensity score matching method to evaluate the effects of Head Start on children's kindergarten retention, reading and math achievement in fall kindergarten comparing with center-based care. Both parametric and nonparametric…

GETTING READY: RESULTS OF A RANDOMIZED TRIAL OF A RELATIONSHIP-FOCUSED INTERVENTION ON THE PARENT–INFANT RELATIONSHIP IN RURAL EARLY HEAD START

Science.gov (United States)

KNOCHE, LISA L.; SHERIDAN, SUSAN M.; CLARKE, BRANDY L.; EDWARDS, CAROLYN POPE; MARVIN, CHRISTINE A.; CLINE, KEELY D.; KUPZYK, KEVIN A.

2014-01-01

The purpose of this study is to investigate the effects of a relational intervention (the Getting Ready intervention) on parenting behaviors supporting the parent–infant relationship for families enrolled in Early Head Start home-based programming. Two-hundred thirty-four parents and their children participated in the randomized study, with 42% of parents reporting education of less than a high-school diploma. Brief, semistructured parent–child interaction tasks were videotaped every 4 months over a16-month intervention period. Observational codes of parent–infant relationship behaviors included quality of three parental behaviors: warmth and sensitivity, support for learning, and encouragement of autonomy; two appropriateness indicators: support for learning and guidance/directives; and one amount indicator: constructive behaviors. Parents who participated in the Getting Ready intervention demonstrated higher quality interactions with their children that included enhanced quality of warmth and sensitivity, and support for their children’s autonomy than did parents in the control group. They also were more likely to use appropriate directives with their children and more likely to demonstrate appropriate supports for their young children’s learning. Results indicate an added value of the Getting Ready intervention for Early Head Start home-based programming for families of infants and toddlers. PMID:24644374

IMPLEMENTING AN ATTACHMENT-BASED PARENTING INTERVENTION WITHIN HOME-BASED EARLY HEAD START: HOME-VISITORS' PERCEPTIONS AND EXPERIENCES.

Science.gov (United States)

West, Allison L; Aparicio, Elizabeth M; Berlin, Lisa J; Jones Harden, Brenda

2017-07-01

Implementation of evidence-based interventions in "real-world" settings is enhanced when front-line staff view the intervention as acceptable, appropriate, and feasible. This qualitative study addresses Early Head Start (EHS) home visitors' perceptions and experiences of an evidence-based parenting intervention, the Attachment and Biobehavioral Catch-up program (M. Dozier, O. Lindhiem, & J. Ackerman, 2005), when added to EHS services as usual within the context of a research-practice partnership. Thematic analysis of in-depth, qualitative interviews indicates that home visitors experienced the intervention as positive and helpful for EHS families. Some challenges included scheduling and uncertainty regarding the goals of the intervention. Concerns over participation in the research centered on information exchange, confidentiality, and time limitations. © 2017 Michigan Association for Infant Mental Health.

Microbiology and performance of a methanogenic biofilm reactor during the start-up period.

Science.gov (United States)

Cresson, R; Dabert, P; Bernet, N

2009-03-01

To understand the interactions between anaerobic biofilm development and process performances during the start-up period of methanogenic biofilm reactor. Two methanogenic inverse turbulent bed reactors have been started and monitored for 81 days. Biofilm development (adhesion, growth, population dynamic) and characteristics (biodiversity, structure) were investigated using molecular tools (PCR-SSCP, FISH-CSLM). Identification of the dominant populations, in relation to process performances and to the present knowledge of their metabolic activities, was used to propose a global scheme of the degradation routes involved. The inoculum, which determines the microbial species present in the biofilm influences bioreactor performances during the start-up period. FISH observations revealed a homogeneous distribution of the Archaea and bacterial populations inside the biofilm. This study points out the link between biodiversity, functional stability and methanogenic process performances during start-up of anaerobic biofilm reactor. It shows that inoculum and substrate composition greatly influence biodiversity, physiology and structure of the biofilm. The combination of molecular techniques associated to a biochemical engineering approach is useful to get relevant information on the microbiology of a methanogenic growing biofilm, in relation with the start-up of the process.

Modelling and Predicting Backstroke Start Performance Using Non-Linear and Linear Models.

Science.gov (United States)

de Jesus, Karla; Ayala, Helon V H; de Jesus, Kelly; Coelho, Leandro Dos S; Medeiros, Alexandre I A; Abraldes, José A; Vaz, Mário A P; Fernandes, Ricardo J; Vilas-Boas, João Paulo

2018-03-01

Our aim was to compare non-linear and linear mathematical model responses for backstroke start performance prediction. Ten swimmers randomly completed eight 15 m backstroke starts with feet over the wedge, four with hands on the highest horizontal and four on the vertical handgrip. Swimmers were videotaped using a dual media camera set-up, with the starts being performed over an instrumented block with four force plates. Artificial neural networks were applied to predict 5 m start time using kinematic and kinetic variables and to determine the accuracy of the mean absolute percentage error. Artificial neural networks predicted start time more robustly than the linear model with respect to changing training to the validation dataset for the vertical handgrip (3.95 ± 1.67 vs. 5.92 ± 3.27%). Artificial neural networks obtained a smaller mean absolute percentage error than the linear model in the horizontal (0.43 ± 0.19 vs. 0.98 ± 0.19%) and vertical handgrip (0.45 ± 0.19 vs. 1.38 ± 0.30%) using all input data. The best artificial neural network validation revealed a smaller mean absolute error than the linear model for the horizontal (0.007 vs. 0.04 s) and vertical handgrip (0.01 vs. 0.03 s). Artificial neural networks should be used for backstroke 5 m start time prediction due to the quite small differences among the elite level performances.

Impact of Early Head Start in North Carolina on Dental Care Use Among Children Younger Than 3 Years.

Science.gov (United States)

Burgette, Jacqueline M; Preisser, John S; Weinberger, Morris; King, Rebecca S; Lee, Jessica Y; Rozier, R Gary

2017-04-01

To examine the effects of North Carolina Early Head Start (EHS), an early education program for low-income children younger than 3 years and their families, on dental care use among children. We performed a quasi-experimental study in which we interviewed 479 EHS and 699 non-EHS parent-child dyads at baseline (2010-2012) and at a 24-month follow-up (2012-2014). We estimated the effects of EHS participation on the probability of having a dental care visit after controlling for baseline dental care need and use and a propensity score covariate; we included random effects to account for EHS program clustering. The odds of having a dental care visit of any type (adjusted odds ratio [OR] = 2.5; 95% confidence interval [CI] = 1.74, 3.48) and having a preventive dental visit (adjusted OR = 2.6; 95% CI = 1.84, 3.63) were higher among EHS children than among non-EHS children. In addition, the adjusted mean number of dental care visits among EHS children was 1.3 times (95% CI = 1.17, 1.55) the mean number among non-EHS children. This study is the first, to our knowledge, to demonstrate that EHS participation increases dental care use among disadvantaged young children.

An Anaylsis of Pretest and Post Test Scores of Head Start African American, Hispanic American and European American Students Engaged in an Intensive Emergent Literacy Program.

Science.gov (United States)

Baumgarten, Thomas L.; Minix, Quinella

The Texas Education Agency awarded twenty competitive grants to Head Start programs in the state. The focus of the grants was on emergent literacy and pre-reading skills. Teachers, mentors, and administrators underwent intensive training. To investigate whether children emerged from the grant programs ready to enter school reading, an outside…

Influence of physical development on start and countermovement jump performance in adolescent sprint athletes.

Science.gov (United States)

Aerenhouts, D; Debaere, S; Hagman, F; Van Gheluwe, B; Delecluse, C; Clarys, P

2013-02-01

The aim of the present study was to describe the effect of physical changes during adolescence on sprint start and countermovement jump (CMJ) performance. Twenty-eight girls and 25 boys (15.0±1.6 and 14.7±1.9 years at start respectively) were measured twice with a one year interval. Anthropometric data allowed skeletal muscle mass (SMM) estimation. Athletes performed a 10m sprint tracked from behind by a laser sensor, with starting blocks measuring propulsion forces. CMJ's were performed on a Kistler force plate. Between the two measurement occasions both genders increased in body height, weight and SMM. In girls and boys, impulse during the push-off, block leaving velocity and times at 5 and 10 m improved significantly. In both genders CMJ absolute power increased but not power.kg-1. Only in boys a higher CMJ was registered on occasion 2. For both genders on both occasions, impulse during the push-off correlated with body weight, SMM and CMJ power (r from .46 to .84), and in boys also with CMJ height and CMJ power.kg-1 (r from 0.43 to 0.76). Boys showed CMJ height and power to correlate with 5 and 10 m times (r from -0.42 to -0.79) and with block leaving velocity, however only on the first data collection (r=0.61 and 0.59, respectively). Sprint start performance is only partly related to muscular development and CMJ could predict start performance in boys only. Sprint start and CMJ rely on technical skills and, therefore, increasing muscularity should be accompanied with sufficient specific training to allow an optimal transfer to start performance.

Child Behavior Problems, Teacher Executive Functions, and Teacher Stress in Head Start Classrooms

Science.gov (United States)

Friedman-Krauss, Allison H.; Raver, C. Cybele; Neuspiel, Juliana M.; Kinsel, John

2017-01-01

Research Findings The current article explores the relationship between teachers’ perceptions of child behavior problems and preschool teacher job stress, as well as the possibility that teachers’ executive functions moderate this relationship. Data came from 69 preschool teachers in 31 early childhood classrooms in 4 Head Start centers and were collected using Web-based surveys and Web-based direct assessment tasks. Multilevel models revealed that higher levels of teachers’ perceptions of child behavior problems were associated with higher levels of teacher job stress and that higher teacher executive function skills were related to lower job stress. However, findings did not yield evidence for teacher executive functions as a statistical moderator. Practice or Policy Many early childhood teachers do not receive sufficient training for handling children’s challenging behaviors. Child behavior problems increase a teacher’s workload and consequently may contribute to feelings of stress. However, teachers’ executive function abilities may enable them to use effective, cognitive-based behavior management and instructional strategies during interactions with students, which may reduce stress. Providing teachers with training on managing challenging behaviors and enhancing executive functions may reduce their stress and facilitate their use of effective classroom practices, which is important for children’s school readiness skills and teachers’ health. PMID:28596698

Class start times, sleep, and academic performance in college: a path analysis.

Science.gov (United States)

Onyper, Serge V; Thacher, Pamela V; Gilbert, Jack W; Gradess, Samuel G

2012-04-01

Path analysis was used to examine the relationship between class start times, sleep, circadian preference, and academic performance in college-aged adults. Consistent with observations in middle and high school students, college students with later class start times slept longer, experienced less daytime sleepiness, and were less likely to miss class. Chronotype was an important moderator of sleep schedules and daytime functioning; those with morning preference went to bed and woke up earlier and functioned better throughout the day. The benefits of taking later classes did not extend to academic performance, however; grades were somewhat lower in students with predominantly late class schedules. Furthermore, students taking later classes were at greater risk for increased alcohol consumption, and among all the factors affecting academic performance, alcohol misuse exerted the strongest effect. Thus, these results indicate that later class start times in college, while allowing for more sleep, also increase the likelihood of alcohol misuse, ultimately impeding academic success.

Head and Neck Cancer—Patient Version

Science.gov (United States)

Head and neck cancers include cancers in the larynx (voice box), throat, lips, mouth, nose, and salivary glands. Start here to find information on head and neck cancer treatment in adults and children, causes and prevention, screening, research, and statistics.

A fast-start pacing strategy speeds pulmonary oxygen uptake kinetics and improves supramaximal running performance.

Directory of Open Access Journals (Sweden)

Tiago Turnes

Full Text Available The focus of the present study was to investigate the effects of a fast-start pacing strategy on running performance and pulmonary oxygen uptake (VO2 kinetics at the upper boundary of the severe-intensity domain. Eleven active male participants (28±10 years, 70±5 kg, 176±6 cm, 57±4 mL/kg/min visited the laboratory for a series of tests that were performed until exhaustion: 1 an incremental test; 2 three laboratory test sessions performed at 95, 100 and 110% of the maximal aerobic speed; 3 two to four constant speed tests for the determination of the highest constant speed (HS that still allowed achieving maximal oxygen uptake; and 4 an exercise based on the HS using a higher initial speed followed by a subsequent decrease. To predict equalized performance values for the constant pace, the relationship between time and distance/speed through log-log modelling was used. When a fast-start was utilized, subjects were able to cover a greater distance in a performance of similar duration in comparison with a constant-pace performance (constant pace: 670 m±22%; fast-start: 683 m±22%; P = 0.029; subjects also demonstrated a higher exercise tolerance at a similar average speed when compared with constant-pace performance (constant pace: 114 s±30%; fast-start: 125 s±26%; P = 0.037. Moreover, the mean VO2 response time was reduced after a fast start (constant pace: 22.2 s±28%; fast-start: 19.3 s±29%; P = 0.025. In conclusion, middle-distance running performances with a duration of 2-3 min are improved and VO2 response time is faster when a fast-start is adopted.

Relationship Between Vertical Jump Height and Swimming Start Performance Before and After an Altitude Training Camp.

Science.gov (United States)

García-Ramos, Amador; Padial, Paulino; de la Fuente, Blanca; Argüelles-Cienfuegos, Javier; Bonitch-Góngora, Juan; Feriche, Belén

2016-06-01

This study aimed (a) to analyze the development in the squat jump height and swimming start performance after an altitude training camp, (b) to correlate the jump height and swimming start performance before and after the altitude training period, and (c) to correlate the percent change in the squat jump height with the percent change in swimming start performance. Fifteen elite male swimmers from the Spanish Junior National Team (17.1 ± 0.8 years) were tested before and after a 17-day training camp at moderate altitude. The height reached in the squat jump exercise with additional loads of 0, 25, 50, 75, and 100% of swimmers' pretest body weight and swimming start performance (time to 5, 10, and 15 m) were the dependent variables analyzed. Significant increases in the jump height (p ≤ 0.05; effect size [ES]: 0.35-0.48) and swimming start performance (p jump height before training (r = -0.56 to -0.77) and after training (r = -0.50 to -0.71). The change in the squat jump height was inversely correlated with the change in the start time at 5 m (r = -0.47), 10 m (r = -0.73), and 15 m (r = -0.62). These results suggest that altitude training can be suitable to enhance explosive performance. The correlations obtained between the squat jump height and start time in the raw and change scores confirm the relevance of having high levels of lower-body muscular power to optimize swimming start performance.

Integrated approach for stress analysis of high performance diesel engine cylinder head

Science.gov (United States)

Chainov, N. D.; Myagkov, L. L.; Malastowski, N. S.; Blinov, A. S.

2018-03-01

Growing thermal and mechanical loads due to development of engines with high level of a mean effective pressure determine requirements to cylinder head durability. In this paper, computational schemes for thermal and mechanical stress analysis of a high performance diesel engine cylinder head were described. The most important aspects in this approach are the account of temperature fields of conjugated details (valves and saddles), heat transfer modeling in a cooling jacket of a cylinder head and topology optimization of the detail force scheme. Simulation results are shown and analyzed.

Evaluating the implementation of a multicomponent asthma education program for Head Start staff.

Science.gov (United States)

Ruvalcaba, Elizabeth; Chung, Shang-En; Rand, Cynthia; Riekert, Kristin A; Eakin, Michelle

2018-03-15

Asthma disproportionately affects minority groups, low income populations, and young children under 5. Head Start (HS) programs predominantly serve this high-risk population, yet staff are not trained on asthma management. The objective of this study was to assess a 5-year, multicomponent HS staff asthma education program in Baltimore City HS programs. All HS programs were offered annual staff asthma education by a medical research team that included didactic lectures and hands-on training. Attendees received continuing education credits. HS staff were anonymously surveyed on asthma knowledge and skills and asthma medication management practices in Year 1 (preimplementation) and Year 5. There was an estimated response rate of 94% for Year 1 and 82% for Year 5. Compared to staff in Year 1, Year 5 staff were significantly more likely to report they had very good knowledge and skills related to asthma [odds ratio (OR) 1.63; p staff reported higher self-assessed knowledge and skills, self-reports of asthma medication management practices, and self-reports of asthma activities compared to Year 1 staff. HS serves high-risk children with asthma, and a multicomponent program can adequately prepare staff to manage asthma in the child care setting. Our results indicate the feasibility of providing efficacious health skill education into child care provider training to reduce asthma knowledge gaps.

Circle of Security–Parenting: A randomized controlled trial in Head Start

Science.gov (United States)

CASSIDY, JUDE; BRETT, BONNIE E.; GROSS, JACQUELYN T.; STERN, JESSICA A.; MARTIN, DAVID R.; MOHR, JONATHAN J.; WOODHOUSE, SUSAN S.

2017-01-01

Although evidence shows that attachment insecurity and disorganization increase risk for the development of psychopathology (Fearon, Bakermans-Kranenburg, van IJzendoorn, Lapsley, & Roisman, 2010; Groh, Roisman, van IJzendoorn, Bakermans-Kranenburg, & Fearon, 2012), implementation challenges have precluded dissemination of attachment interventions on the broad scale at which they are needed. The Circle of Security–Parenting Intervention (COS-P; Cooper, Hoffman, & Powell, 2009), designed with broad implementation in mind, addresses this gap by training community service providers to use a manualized, video-based program to help caregivers provide a secure base and a safe haven for their children. The present study is a randomized controlled trial of COS-P in a low-income sample of Head Start enrolled children and their mothers. Mothers (N = 141; 75 intervention, 66 waitlist control) completed a baseline assessment and returned with their children after the 10-week intervention for the outcome assessment, which included the Strange Situation. Intent to treat analyses revealed a main effect for maternal response to child distress, with mothers assigned to COS-P reporting fewer unsupportive (but not more supportive) responses to distress than control group mothers, and a main effect for one dimension of child executive functioning (inhibitory control but not cognitive flexibility when maternal age and marital status were controlled), with intervention group children showing greater control. There were, however, no main effects of intervention for child attachment or behavior problems. Exploratory follow-up analyses suggested intervention effects were moderated by maternal attachment style or depressive symptoms, with moderated intervention effects emerging for child attachment security and disorganization, but not avoidance; for inhibitory control but not cognitive flexibility; and for child internalizing but not externalizing behavior problems. This initial

Circle of Security-Parenting: A randomized controlled trial in Head Start.

Science.gov (United States)

Cassidy, Jude; Brett, Bonnie E; Gross, Jacquelyn T; Stern, Jessica A; Martin, David R; Mohr, Jonathan J; Woodhouse, Susan S

2017-05-01

Although evidence shows that attachment insecurity and disorganization increase risk for the development of psychopathology (Fearon, Bakermans-Kranenburg, van IJzendoorn, Lapsley, & Roisman, 2010; Groh, Roisman, van IJzendoorn, Bakermans-Kranenburg, & Fearon, 2012), implementation challenges have precluded dissemination of attachment interventions on the broad scale at which they are needed. The Circle of Security-Parenting Intervention (COS-P; Cooper, Hoffman, & Powell, 2009), designed with broad implementation in mind, addresses this gap by training community service providers to use a manualized, video-based program to help caregivers provide a secure base and a safe haven for their children. The present study is a randomized controlled trial of COS-P in a low-income sample of Head Start enrolled children and their mothers. Mothers (N = 141; 75 intervention, 66 waitlist control) completed a baseline assessment and returned with their children after the 10-week intervention for the outcome assessment, which included the Strange Situation. Intent to treat analyses revealed a main effect for maternal response to child distress, with mothers assigned to COS-P reporting fewer unsupportive (but not more supportive) responses to distress than control group mothers, and a main effect for one dimension of child executive functioning (inhibitory control but not cognitive flexibility when maternal age and marital status were controlled), with intervention group children showing greater control. There were, however, no main effects of intervention for child attachment or behavior problems. Exploratory follow-up analyses suggested intervention effects were moderated by maternal attachment style or depressive symptoms, with moderated intervention effects emerging for child attachment security and disorganization, but not avoidance; for inhibitory control but not cognitive flexibility; and for child internalizing but not externalizing behavior problems. This initial randomized

Fostering a Child's Foundational Skills Leading to Self-Determination: A Case Study of a Refugee Family, a Head Start Agency, and Their Family-Professional Partnership

Science.gov (United States)

Haines, Shana Jackson

2013-01-01

This qualitative case study investigated and described the views of both Head Start staff and a refugee family regarding adult fostering of foundational skills leading to self-determination in a young child at risk for disability as well as how these adults worked together in partnership. Chapter 1 provides an overview of this dissertation. It…

Effect of the Children’s Health Activity Motor Program on Motor Skills and Self-Regulation in Head Start Preschoolers: An Efficacy Trial

Directory of Open Access Journals (Sweden)

Leah Elizabeth Robinson

2016-09-01

Full Text Available Self-regulatory skills are broadly defined as the ability to manage emotions, focus attention, and inhibit some behaviors while activating others in accordance with social expectations and are an established indicator of academic success. Growing evidence links motor skills and physical activity to self-regulation. This study examined the efficacy of a motor skills intervention (i.e., the Children’s Health Activity Motor Program, CHAMP that is theoretically grounded in Achievement Goal Theory on motor skill performance and self-regulation in Head Start preschoolers. A sample of 113 Head Start preschoolers (Mage = 51.91 + 6.5 months; 49.5% males were randomly assigned to a treatment (n = 68 or control (n = 45 program. CHAMP participants engaged in 15, 40-minute sessions of a mastery climate intervention that focused on the development of motor skills over 5 weeks while control participants engaged in their normal outdoor recess period. The Delay of Gratification Snack Task was used to measure self-regulation and the Test of Gross Motor Development - 2nd Edition was used to assess motor skills. All measures were assessed prior to and following the intervention. Linear mixed models were fit for both self-regulation and motor skills. Results revealed a significant time*treatment interaction (p < .001. In regards to motor skills, post hoc comparisons found that all children improved their motor skills (p < .05, but the CHAMP group improved significantly more than the control group (p < .001. Children in CHAMP maintained their self-regulation scores across time while children in the control group scored significantly lower than the CHAMP group at the posttest (p < .05. CHAMP is a mastery climate movement program that may be an approach to enhance skills associated with healthy development in children (i.e., motor skills and self-regulation. This efficacy trial provided evidence that CHAMP helped maintain delay of gratification in preschool age

Start-up performance of parabolic trough concentrating solar power plants

DEFF Research Database (Denmark)

Ferruzza, Davide; Topel, Monika; Basaran, Ibrahim

2017-01-01

Concentrating solar power plants, even though they can be integrated with thermal energy storage, are still subjected to cyclic start-up and shut-downs. As a consequence, in order to maximize their profitability and performance, the flexibility with respect to transient operations is essential...

Analysis on the influence of the pump start transient performance with different inertia impeller

International Nuclear Information System (INIS)

Tang, Y; Cheng, J; Liu, E H; Tang, L D

2012-01-01

Centrifugal pump start-up time is very short, in the boot process, the instantaneous head and flow will have an impact role to the pipeline, and however the moment of inertia is one of the main factors affecting centrifugal pump boot acceleration. We analyzed the pump start-up transient characteristics with the different moment of inertia of the impeller corresponding to the different materials, there are three different moment of inertia of the impeller have been selected. At first, we use the 'Flowmaster' fluid system simulation software do the outer characteristics simulation to the selected-model, get the time - flow and the time - speed curve. Then, do the experiments research in the process when pump start-up, and compare with the simulation result. At last use the outer characteristics simulation result as the boundary, using the ANASYS CFX software do the transient simulation to the three groups with different inertia pump impeller, and draw the pressure distribution picture. In according to the analysis, we can confirm that the impact of inertia is one of the factors in the stability during the pump star, and we can get that the greater moment of inertia, the longer the boot stable. We also can get that combined Flowmaster with ANSYS can solved engineering practice problem in fluid system conveniently, and take it easy to solve the similar problem.

Failure Analysis of a Modern High Performance Diesel Engine Cylinder Head

Directory of Open Access Journals (Sweden)

Bingbin Guo

2014-05-01

Full Text Available This paper presents a failure analysis on a modern high performance diesel engine cylinder head made of gray cast iron. Cracks appeared intensively at the intersection of two exhaust passages in the cylinder head. The metallurgical examination was conducted in the crack origin zone and other zones. Meanwhile, the load state of the failure part of the cylinder head was determined through the Finite Element Analysis. The results showed that both the point of the maximum temperature and the point of the maximum thermal-mechanical coupling stress were not in the crack position. The excessive load was not the main cause of the failure. The large cooling rate in the casting process created an abnormal graphite zone that existed below the surface of the exhaust passage (about 1.1 mm depth, which led to the fracture of the cylinder head. In the fractured area, there were a large number of casting defects (dip sand, voids, etc. and inferior graphite structure (type D, type E which caused stress concentration. Moreover, high temperature gas entered the cracks, which caused material corrosion, material oxidization, and crack propagation. Finally, premature fracture of the cylinder head took place.

START: the creation of a spherical tokamak

International Nuclear Information System (INIS)

Sykes, Alan

1992-01-01

The START (Small Tight Aspect Ratio Tokamak) plasma fusion experiment is now operational at AEA Fusion's Culham Laboratory. It is the world's first experiment to explore an extreme limit of the tokamak - the Spherical Tokamak - which theoretical studies predict may have substantial advantages in the search for economic fusion power. The Head of the START project, describes the concept, some of the initial experimental results and the possibility of developing a spherical tokamak power reactor. (author)

Replacement of a vessel head, an operation which today gets easily into its stride

International Nuclear Information System (INIS)

Mardon, P.; Chaumont, J.C.; Lambiotte, P.

1995-01-01

In 1992, one year after the detection of a leak in a vessel head of the Electricite de France (EDF) Bugey 4 reactor, the head was replaced by the Framatome-Jeumont Industrie Group. Today, this group, which has developed new methods and new tools to optimize the cost, the time-delay and the dosimetry of this kind of intervention, has performed 11 additional replacements, two of which on 1300 MWe power units. This paper describes step by step the successive operations required for a complete vessel head replacement, including the testing of safety systems before starting up the reactor. (J.S.). 7 photos

Oral health activities of early head start teachers directed toward children and parents.

Science.gov (United States)

Kranz, Ashley M; Rozier, R Gary; Zeldin, Leslie P; Preisser, John S

2011-01-01

This cross-sectional study examined Early Head Start (EHS) teachers' oral health program activities and their association with teacher and program characteristics. Self-completed questionnaires were distributed to the staff in all EHS programs in North Carolina. Variables for dental health activities for parents (four items) and children (four items) were constructed as the sum of responses to a 0-4 Likert-type scale (never to very frequently). Ordinary least squares regression models examined the association between teachers' oral health program activities and modifiable teacher (oral health knowledge, values, self-efficacy, dental health training, perceived barriers to dental activities) and program (director and health coordinator knowledge and perceived barriers to dental activities) characteristics. Teachers in the parent (n=260) and child (n=231) analyses were a subset of the 485 staff respondents (98 percent response rate). Teachers engaged in child oral health activities (range = 0-16; mean = 9.0) more frequently than parent activities (range = 0-16; mean = 6.9). Teachers' oral health values, perceived oral health self-efficacy, dental training, and director and health coordinator knowledge were positively associated with oral health activities (P oral health activity in EHS programs is less than optimal. Several characteristics of EHS staff were identified that can be targeted with education interventions. Evidence for effectiveness of EHS interventions needs to be strengthened, but results of this survey provide encouraging findings about the potential effects of teacher training on their oral health practices.

Parent Perceptions of Mobile Device Use Among Preschool-Aged Children in Rural Head Start Centers.

Science.gov (United States)

McCloskey, Morgan; Johnson, Susan L; Benz, Cristen; Thompson, Darcy A; Chamberlin, Barbara; Clark, Lauren; Bellows, Laura L

2018-01-01

To describe child use and parents' beliefs and comfort with young children's use of mobile devices in low-income, rural communities. This was a descriptive, cross-sectional study. The survey, which consisted of 18 multiple-part questions, was distributed to families at 5 Head Start/preschool centers in Colorado. In total, 192 surveys were returned (28.5% response rate). Most children (92%) used a smartphone or tablet at some frequency and most parents (90%) had downloaded apps specifically for their child. Education and ethnicity were related to parents' technology beliefs. Parent comfort with technology was positively associated with greater child use of technology (P Mobile device use was relatively high in this sample. Mobile devices appear to be a feasible platform to offer nutrition and physical activity education for this audience. Ensuring parent comfort with technology and apps will be important. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

The Impact of Start-up Grants on Firm Performance in Estonia

Directory of Open Access Journals (Sweden)

Siret Vildo

2013-01-01

Full Text Available As in economic theory start-up enterprises have been seen as important sources of growth, the government support measures to enterprises have been a common practice around the world for decades. As the governmental support to enterprises is often of a considerable amount of money there is a need to assess its efficiency. In the present article we study the impact of Estonian start-up grants distributed in 2002 and 2003 on various indicators of firm performance with econometric methods, namely propensity score matching. We use the data from the Estonian Business Register in order to study the impact of start-up grants on various economic indicators like the number of employees, turnover, equity, fixed assets and firm survival. The results showed that the start-up grants proved to affect positively the number of employed people and turnover, yet the impact on productivity was negative. One implication of the study is that it is difficult to achieve different goals to the same extent with a single governmental grant

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

Center-Based Early Head Start and Children Exposed to Family Conflict

Science.gov (United States)

Whiteside-Mansell, Leanne; Bradley, Robert; McKelvey, Lorraine; Lopez, Maya

2009-01-01

Research Findings: Family conflict is known to be associated with poor development for young children, but many children appear resilient. This study examined the extent to which high-quality center care during early childhood protects children from these negative consequences. Children participating in center-based sites of the Early Head Start…

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(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. Copyright © 2015 Elsevier B.V. All rights reserved.

I Am Really Good at Puzzles, but I Don't Get Asked to Play with Others: Age, Gender, and Ethnic Differences in Head Start Children's Self-Perceptions of Competence

Science.gov (United States)

Mantzicopoulos, Panayota

2004-01-01

The author examined age, gender, and ethnic differences in the self-perceptions of 112 low-income children who were assessed with the Pictorial Scale of Perceived Competence and Social Acceptance (PSPCSA) at Head Start and kindergarten. Children's self-ratings of competence were overly optimistic across the 4 subscales of the PSPCSA during the 2…

Implementing a Nutrition and Physical Activity Curriculum in Head Start Through an Academic-Community Partnership.

Science.gov (United States)

Zahnd, Whitney E; Smith, Tracey; Ryherd, Susan J; Cleer, Melissa; Rogers, Valerie; Steward, David E

2017-06-01

Schools may be an effective avenue for interventions that prevent childhood obesity. I am Moving I am Learning/Choosy Kids © (IMIL/CK) is a curriculum recommended by Head Start (HS) for education in nutrition, physical activity, and healthy lifestyle habits. We formed an academic-community partnership (ACP), the Springfield Collaborative for Active Child Health, to promote prevention of childhood obesity, in part, to implement the IMIL/CK curriculum in local HS sites. The ACP included a medical school, HS program, public school district, and state health department. Community-based participatory research principles helped identify and organize important implementation activities: community engagement, curriculum support, professional teacher training, and evaluation. IMIL/CK was piloted in 1 school then implemented in all local HS sites. All sites were engaged in IMIL/CK professional teacher training, classroom curriculum delivery, and child physical activity assessments. Local HS policy changed to include IMIL/CK in lesson plans and additional avenues of collaboration were initiated. Furthermore, improvements in physical activity and/or maintenance or improvement of healthy weight prevalence was seen in 4 of the 5 years evaluated. An ACP is an effective vehicle to implement and evaluate childhood obesity prevention programming in HS sites. © 2017, American School Health Association.

AFROC analysis of reporting radiographer's performance in CT head interpretation

International Nuclear Information System (INIS)

Lockwood, P.; Piper, K.

2015-01-01

Aim: A preliminary small scale study to assess the diagnostic performance of a limited group of reporting radiographers and consultant radiologists in clinical practice undertaking computed tomography (CT) head interpretation. Method: A multiple reader multiple case (MRMC) alternative free response receiver operating characteristic (AFROC) methodology was applied. Utilising an image bank of 30 CT head examinations, with a 1:1 ratio of normal to abnormal cases. A reference standard was established by double reporting the original reports using two additional independent consultant radiologists with arbitration of discordance by the researcher. Twelve observers from six southern National Health Service (NHS) trusts were invited to participate. The results were compared for accuracy, agreement, sensitivity, specificity. Data analysis used AFROC and area under the curve (AUC) with standard error. Results: The reporting radiographers results demonstrated a mean sensitivity rate of 88.7% (95% CI 82.3–95.1%), specificity 95.6% (96% CI 90.1–100%) and accuracy of 92.2% (95% CI 89.3–95%). The consultant radiologists mean sensitivity rate was 83.35% (95% CI 80–86.7%), specificity 90% (95% CI 86.7–93.3%) and accuracy of 86.65% (95% CI 83.3–90%). Observer performance between the two groups was compared with AFROC, AUC, and standard error analysis (p = 0.94, SE 0.202). Conclusion: The findings of this research indicate that within a limited study, a small group of reporting radiographers demonstrated high levels of diagnostic accuracy in the interpretation of CT head examinations that was equivalent to a small selection of consultant radiologists. - Highlights: • We assessed reporting radiographers and consultant radiologists in a clinical setting. • This was a small scale retrospective multi-reader multi-case multi-site study. • AFROC used lesion-based decisions rather than case-based decisions. • Within a limited study the observed performance was high in

A preliminary examination of neurocognitive performance and symptoms following a bout of soccer heading in athletes wearing protective soccer headbands.

Science.gov (United States)

Elbin, R J; Beatty, Amanda; Covassin, Tracey; Schatz, Philip; Hydeman, Ana; Kontos, Anthony P

2015-01-01

This study compared changes in neurocognitive performance and symptom reports following an acute bout of soccer heading among athletes with and without protective soccer headgear. A total of 25 participants headed a soccer ball 15 times over a 15-minute period, using a proper linear heading technique. Participants in the experimental group completed the heading exercise while wearing a protective soccer headband and controls performed the heading exercise without wearing the soccer headband. Neurocognitive performance and symptom reports were assessed before and after the acute bout of heading. Participants wearing the headband showed significant decreases on verbal memory (p = 0.02) compared with the no headband group, while the no headband group demonstrated significantly faster reaction time (p = 0.03) than the headband group following the heading exercise. These findings suggest that protective soccer headgear likely does not mitigate the subtle neurocognitive effects of acute soccer heading.

Muslim dress and the head-scarf debate

NARCIS (Netherlands)

Moors, A.; Skov, L.

2010-01-01

Debates about the presence of students wearing head scarves in public schools in West Europe started in the late 1980s; about a decade later, the employment of women wearing head scarves also became the focus of attention. These debates need to be seen within a context in which a new generation of

Start and turn performances of elite sprinters at the 2016 European Championships in swimming.

Science.gov (United States)

Morais, Jorge E; Marinho, Daniel A; Arellano, Raul; Barbosa, Tiago M

2018-03-26

The aim of this study was to examine the performance characteristics of male and female finalists in the 100-m distance at the 2016 European Championships in swimming (long-course-metre). The performances of all 64 (32-males and 32-females) were analysed (8 swimmers per event; Freestyle, Backstroke, Breaststroke and Butterfly). A set of start and turn parameters were analysed. In the start main outcome, male swimmers were faster in Butterfly (5.71 ± 0.14s) and females in Freestyle (6.68 ± 0.28s). In the turn main outcome, male and female swimmers were faster in Freestyle (males: 9.55 ± 0.13s; females: 10.78 ± 0.28s). A significant and strong stroke effect was noted in the start and turn main outcome, in both sexes. In the start plus the turn combined, males and females were faster in Freestyle (males: 15.40 ± 0.20s; females: 17.45 ± 0.54s). The start and the turn combined accounted almost one-third of the total race time in all events, and non-significant differences (p > 0.05) were noted across the four swim strokes. Once this research made evident the high relevance of start and turns, it is suggested that coaches and swimmers should dedicate an expressive portion of the training perfecting these actions.

The impact of dry-land sprint start training on the short track speed skating start.

Science.gov (United States)

Haug, William B; Drinkwater, Eric J; Cicero, Nicholas J; Barthell, J Anthony; Chapman, Dale W

2017-05-05

This investigation sought to determine the effects of dry-land sprint start training on short track speed skating (STSS) start performance. Nine highly trained short track athletes completed a control period of normal STSS training followed by a four-week training intervention. Before and after the control and intervention periods, athletes performed three electronically timed dry-land and on-ice 14.43 m maximal sprint start efforts. The intervention consisted of two sprint sessions per week consisting of nine electronically timed 14.43 m dry-land sprint starts in addition to normal STSS training. The control period resulted in no substantial change in on-ice start performance (Mean Δ: -0.01 s, 95% Confidence Limits (CL): -0.08 to 0.05 s; Effect Size (ES): -0.05; Trivial) however, a small change was observed in dry-land start performance (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.02 s; ES: -0.49). Following brief specific dry-land sprint start training a small improvement was observed in both on-ice (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.01 s; ES: -0.33) and dry-land (Mean Δ: -0.04 s, 95% CL: -0.09 to 0.00 s; ES: -0.29) start performance. This investigation suggests STSS start performance can be improved through a brief dry-land sprint start training program.

Vortex Formation and Acceleration of a Fish-Inspired Robot Performing Starts from Rest

Science.gov (United States)

Devoria, Adam; Bapst, Jonathan; Ringuette, Matthew

2009-11-01

We investigate the unsteady flow of a fish-inspired robot executing starts from rest, with the objective of understanding the connection among the kinematics, vortex formation, and acceleration performance. Several fish perform ``fast starts,'' where the body bends into a ``C'' or ``S'' shape while turning (phase I), followed by a straightening of the body and caudal fin and a linear acceleration (phase II). The resulting highly 3-D, unsteady vortex formation and its relationship to the acceleration are not well understood. The self-propelled robotic model contains motor-driven joints with programmable motion to emulate phase II of a simplified C-start. The experiments are conducted in a water tank, and the model is constrained to 1 direction along rails. The velocity is measured using digital particle image velocimetry (DPIV) in multiple planes. Vortex boundaries are identified using the finite-time Lyapunov exponent, then the unsteady vortex circulation is computed. The thrust is estimated from the identified vortices, and correlated with the circulation and model acceleration for different kinematics.

Barbara Ryder to head Department of Computer Science

OpenAIRE

Daniilidi, Christina

2008-01-01

Barbara G. Ryder, professor of computer science at Rutgers, The State University of New Jersey, will become the computer science department head at Virginia Tech, starting in fall 2008. She is the first woman to serve as a department head in the history of the nationally ranked College of Engineering.

Start-up conditions and the performance of women - and men - controlled businesses in manufacturing industries

Directory of Open Access Journals (Sweden)

Otilia Driga

2010-01-01

Full Text Available Recent research into the economic performance of women-controlled firms suggests that their underperformance may not be the result of differences in the managerial ability of women as compared to men, and that it may in fact be a consequence of differing levels of start-up resources. Using accounting data, we examine the effects that selected start-up conditions have had on the observed economic performance of a sample of 4450 Spanish manufacturing firms. The results, which indicate significant differences in the initial conditions and show lower levels of assets and employee numbers in women-controlled firms, have implications for the economic performance of such firms.

Experiment on performance of upper head injection system with ROSA-II

International Nuclear Information System (INIS)

1976-09-01

Thermo-hydraulic behavior in the primary cooling system of a pressurized water reactor with an upper head injection system (UHI) in a postulated loss-of-coolant accident (LOCA) has been studied with ROSA-II test facility. Simulated UHI and internal structures of the pressure vessel were installed to the facility for the experiment. Nine maximum-sized double-ended break tests and one medium-sized split break test were performed for the cold-leg break condition. The results are as follows: (1) Fluid mixing in the upper head is not perfect. (2) Cold water injection into the steam or two-phase fluid causes violent depressurization due to the condensation. Flow pattern in the primary cooling system is largely influenced by the above two. (auth.)

Improving on-time surgical starts: the impact of implementing pre-OR timeouts and performance pay.

Science.gov (United States)

Martin, Luke; Langell, John

2017-11-01

Operating room (OR) time is expensive. Underutilized OR time negatively impacts efficiency and is an unnecessary cost for hospitals. The purpose of this study was to evaluate the impact of a pre-OR timeout and performance pay incentive on the frequency of on-time, first surgical starts. At a single Veterans Affairs Medical Center, we implemented a pre-OR timeout in the form of a safety-briefing checklist and a modest performance pay incentive for on-time starts (>90% compliance) for attending surgeons. Data were collected on all first-start cases beginning before implementation in 2008 and continued through 2015. Each year, an average of 960 first starts occurred across nine surgical divisions. Before implementation of either the timeout or pay incentive, only 15% of cases started on time, and by 2015, greater than 72% were on time (P 60 min were not significant (P = 0.31; P = 0.81). Assuming a loss of 7 min per case for delays pay for on-time starts significantly improves OR utilization and reduces unnecessary costs. Published by Elsevier Inc.

Desert Tortoise Head-start Program at Twentynine Palms Marine Base

Science.gov (United States)

2013-04-02

starting method, extinction , predation, mortality, survivorship Kenneth An Nagy, Scott Hillard University of California - Los Angeles Regents of the...the netting problems were corrected. The remaining two predators were ants : native fire ants (Solenopsis xyloni—already known as hatchling...predators from another study site) and common Harvester Ants , Pogonomyrmex californicus. Both have been controlled when and where necessary by cautious use

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 0.05). Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.

Role of Starting School Age in the Academic Performance at the Tertiary Level

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Mahwish Ali Baber

2017-11-01

Full Text Available The purpose of this research was to find out whether starting school earlier than four years of age gave any academic benefit to the students in the long run. This research aimed to find out whether the students who started schooling earlier than four years of age are able to achieve better grades and are better at self-regulation at the tertiary level. For this purpose, a sample of 108 students from a private business school comprising both early and late school starters were made to fill in questionnaires reporting their school starting age, their CGPA and answering questions that showed their level of self-regulation. The findings of this study suggest that there is no difference in the academic performance of the two groups, both in terms of their CGPA and their self-regulation skills.

Do you use your head or follow your heart? Self-location predicts personality, emotion, decision making, and performance.

Science.gov (United States)

Fetterman, Adam K; Robinson, Michael D

2013-08-01

The head is thought to be rational and cold, whereas the heart is thought to be emotional and warm. In 8 studies (total N = 725), we pursued the idea that such body metaphors are widely consequential. Study 1 introduced a novel individual difference variable, one asking people to locate the self in the head or the heart. Irrespective of sex differences, head-locators characterized themselves as rational, logical, and interpersonally cold, whereas heart-locators characterized themselves as emotional, feminine, and interpersonally warm (Studies 1-3). Study 4 showed that head-locators were more accurate in answering general knowledge questions and had higher grade point averages, and Study 5 showed that heart-locators were more likely to favor emotional over rational considerations in moral decision making. Study 6 linked self-locations to reactivity phenomena in daily life--for example, heart-locators experienced greater negative emotion on high stressor days. In Study 7, we manipulated attention to the head versus the heart and found that head-pointing facilitated intellectual performance, whereas heart-pointing led to emotional decision making. Study 8 replicated Study 3's findings with a nearly year-long delay between the self-location and outcome measures. The findings converge on the importance of head-heart metaphors for understanding individual differences in cognition, emotion, and performance.

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

Directory of Open Access Journals (Sweden)

Amador García-Ramos

Full Text Available 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 0.05. Trivial changes in peak velocity were obtained during the loaded squat jump after both training periods (effect sizes: < 0.20. Based on these results we can conclude that a traditional training high-living high strategy concurrent training of 3 weeks does not adversely affect swimming start time and loaded squat jump performance in high level swimmers, but further studies are necessary to assess the effectiveness of power-oriented resistance training in the development of explosive actions.

The Impact of a Good Season Start on Team Performance in Elite Handball

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Lago-Peñas Carlos

2016-04-01

Full Text Available The aim of the current study was (i to identify how important was a good season start in relation to elite handball teams’ performance, and (ii to examine if this impact was related to the clubs’ financial budget. The match performances and annual budgets of all teams were collected from the Spanish Professional Handball League during ten seasons. The dependent variable was the difference between the ranking of each team in accordance to the annual budget and the ranking of each team at the end of the season. A k-means cluster analysis classified the clubs according to their budget as High Range Budget Clubs (HRBC, Upper-Mid Range Budget Clubs (UMRBC, Lower-Mid Range Budget Clubs (LMRBC and Low Range Budget Clubs (LRBC. Data were examined through linear regression models. Overall, the results suggested that the better the team performance at the beginning of the season, the better the ranking at the end of the season. Each position in the ranking above expected in accordance to the budget of the teams in Rounds 3, 4 or 5 improved by 0.47, 0.50 or 0.49, respectively, in the ranking at the end of the season (p<0.05. However, the impact of the effect depended on the clubs’ annual budget. For UMRBC, LMRBC and LRBC a good start to the season had a positive effect on the final outcome (p<0.05. Nevertheless, for HRBC, a good or a bad start of the season did not explain their final position. These variables can be used to develop accurate models to estimate final rankings. UMRBC, LMRBC and LRBC can benefit from fine-tuning preseason planning in order to accelerate the acquisition of optimal performances.

Classroom-based Interventions and Teachers' Perceived Job Stressors and Confidence: Evidence from a Randomized Trial in Head Start Settings.

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Zhai, Fuhua; Raver, C Cybele; Li-Grining, Christine

2011-09-01

Preschool teachers' job stressors have received increasing attention but have been understudied in the literature. We investigated the impacts of a classroom-based intervention, the Chicago School Readiness Project (CSRP), on teachers' perceived job stressors and confidence, as indexed by their perceptions of job control, job resources, job demands, and confidence in behavior management. Using a clustered randomized controlled trial (RCT) design, the CSRP provided multifaceted services to the treatment group, including teacher training and mental health consultation, which were accompanied by stress-reduction services and workshops. Overall, 90 teachers in 35 classrooms at 18 Head Start sites participated in the study. After adjusting for teacher and classroom factors and site fixed effects, we found that the CSRP had significant effects on the improvement of teachers' perceived job control and work-related resources. We also found that the CSRP decreased teachers' confidence in behavior management and had no statistically significant effects on job demands. Overall, we did not find significant moderation effects of teacher race/ethnicity, education, teaching experience, or teacher type. The implications for research and policy are discussed.

The relationship between executive functioning and language: Examining vocabulary, syntax, and language learning in preschoolers attending Head Start.

Science.gov (United States)

White, Lisa J; Alexander, Alexandra; Greenfield, Daryl B

2017-12-01

Early childhood marks a time of dynamic development within language and cognitive domains. Specifically, a body of research focuses on the development of language as related to executive functions, which are foundational cognitive skills that relate to both academic achievement and social-emotional development during early childhood and beyond. Although there is evidence to support the relationship between language and executive functions, existing studies focus mostly on vocabulary and fail to examine other components of language such as syntax and language learning skills. To address this gap, this study examined the relationship between executive functioning (EF) and three aspects of language: syntax, vocabulary, and language learning. A diverse sample of 182 children (67% Latino and 33% African American) attending Head Start were assessed on both EF and language ability. Findings demonstrated that EF related to a comprehensive latent construct of language composed of vocabulary, syntax, and language learning. EF also related to each individual component of language. This study furthers our understanding of the complex relationship between language and cognitive development by measuring EF as it relates to various components of language in a sample of preschoolers from low-income backgrounds. Copyright © 2017 Elsevier Inc. All rights reserved.

Root Shock Revisited: Perspectives of Early Head Start Mothers on Community and Policy Environments and Their Effects on Child Health, Development, and School Readiness

Science.gov (United States)

McAllister, Carol L.; Thomas, Tammy L.; Green, Beth L.

2009-01-01

Racial differences in school readiness are a form of health disparity. By examining, from the perspective of low-income minority families participating in an Early Head Start study, community and policy environments as they shape and inform lived experiences, we identified several types of social and economic dislocation that undermine the efforts of parents to ready their children for school. The multiple dislocations of community triggered by housing and welfare reform and “urban renewal” are sources of stress for parents and children and affect the health and development of young children. Our findings suggest that racial differences in school readiness result not from race but from poverty and structural racism in American society. PMID:19059871

Hydrocoil Turbine Performance at 3 m, 4 m, and 5 m Head Analysis Using Computational Fluid Dynamics Method

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Luthfie, A. A.; Pratiwi, S. E.; Hidayatulloh, P.

2018-03-01

Indonesia is a country which has abundant renewable energy resources, comprises of water, solar, geothermal, wind, bioenergy, and ocean energy. Utilization of water energy through MHP is widely applied in remote areas in Indonesia. This utilization requires a water-converting device known as a water turbine. Rosefsky (2010) developed a water turbine known as the Hydrocoil turbine. This turbine is an axial turbine which is a modification of screw turbine. This turbine has a pitch length that decreases in the direction of the water flow and is able to work at relatively low water flow and head. The use of Hydrocoil turbine has not been widely applied in Indonesia, therefore this research is focused on analyzing the performance of Hydrocoil turbine. The analysis was performed using Computational Fluid Dynamics (CFD) method. Hydrocoil turbine performance analysis was performed at 3 m, 4 m, and 5 m head respectively as well as rotational speed variations of 100 rpm, 300 rpm, 500 rpm, 700 rpm, 900 rpm, 1,100 rpm, 1,300 rpm, 1,500 rpm, 1,700 rpm, and 1,900 rpm. Based on simulation result, the largest power generated by the turbine at 3 m head is 1,134.06 W, while at 4 m and 5 m are 1,722.39 W and 2,231.49 W respectively. It is also found that the largest turbine’s efficiency at 3 m head is 93.22% while at 4 m and 5 m head are 94.6% and 89.88% respectively. The result also shows that the larger the head the greater the operational rotational speed range.

Oral care for patients with head and neck cancer in Hokkaido University Hospital

International Nuclear Information System (INIS)

Hata, Hironobu; Yamazaki, Yutaka; Imamachi, Kenji

2011-01-01

We have been providing oral care for patients with head and neck cancer in Hokkaido University Hospital since 2007. In this paper, we report clinical statistics of the 254 head and neck cancer patients who received oral care. About 80 percent of these patients were treated with radiation therapy, so it is important to cope with adverse events related to such therapy. Oral care is helpful for cancer patients when it is started as soon as possible (at least 1 week before radiation therapy is started). The percentage of patients who could start oral care 4 days before radiation therapy gradually increased to about 60 percent by fiscal 2009. In fiscal 2010, the percentage decreased to its lowest level of 37.9 percent. To start oral care for all patients 7 days before irradiation, we are going to change our system and start oral care in the outpatient period. In their hometowns, oral care was continued for only 19 (27.0 percent) of the 74 patients who could not visit our hospital. An important task for our project is to establish a medical cooperation system for discharged patients treated for head and neck cancer. (author)

Three nonlinear performance relationships in the start-up state of IPMC strips based on finite element analysis

International Nuclear Information System (INIS)

Peng, Han Min; Ding, Qing Jun; Hui, Yao; Li, Hua Feng; Zhao, Chun Sheng

2010-01-01

Ionic polymer–metal composites (IPMC) are a class of electroactive polymers (EAP), and they currently attract numerous researchers to study their performance characteristics and applications. However, research on its start-up characteristics still requires more attention. In the IPMC start-up state (the moment of applying an actuation voltage at the very beginning), its mechanical performance is different in the stable working state (working for at least 10 min). Therefore, this paper focuses on three performance relationships of an IPMC strip between its maximal tip deformation and voltage, its maximal stress and voltage, as well as its maximal strain and voltage, both in the two states. Different from other reports, we found that they present nonlinear tendencies in the start-up state rather than linear ones. Therefore, based on the equivalent bimorph beam model, a finite element electromechanical coupling calculation module in the ANSYS software was utilized to simulate these characteristics. Furthermore, a test system is introduced to validate the phenomena. As a whole, these three relationships and the FEA method may be beneficial for providing control strategies effectively to IPMC actuators, especially in their start-up states

CMS Tracker Alignment Performance Results Start-Up 2017

CERN Document Server

CMS Collaboration

2017-01-01

During the LHC shutdown in Winter 2016/17, the CMS pixel detector, the inner component of the CMS Tracker, was replaced by the Phase-1 upgrade detector. Among others improvements, the new pixel detector consists of four instead of three layers in the central barrel region (BPIX) and three instead of two disks in the endcap regions (FPIX). In this report, performance plots of the first pixel-detector alignment results are presented, which were obtained with cosmic-ray data taken prior to the start of the 2017 LHC pp operation. Alignment constants have been derived using the data collected initially at 0T and later at 3.8T magnetic field to the level of single module positions in the pixel detector, while keeping the alignment parameters of the strip detector fixed at the values determined in the end of 2016. The complete understanding of the alignment and biases was derived by using two algorithms, Millepede-II and HipPy. The results confirm each other.

Is 8:30 a.m. Still Too Early to Start School? A 10:00 a.m. School Start Time Improves Health and Performance of Students Aged 13–16

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Paul Kelley

2017-12-01

Full Text Available While many studies have shown the benefits of later school starts, including better student attendance, higher test scores, and improved sleep duration, few have used starting times later than 9:00 a.m. Here we report on the implementation and impact of a 10 a.m. school start time for 13 to 16-year-old students. A 4-year observational study using a before-after-before (A-B-A design was carried out in an English state-funded high school. School start times were changed from 8:50 a.m. in study year 0, to 10 a.m. in years 1–2, and then back to 8:50 a.m. in year 3. Measures of student health (absence due to illness and academic performance (national examination results were used for all students. Implementing a 10 a.m. start saw a decrease in student illness after 2 years of over 50% (p < 0.0005 and effect size: Cohen's d = 1.07, and reverting to an 8:50 a.m. start reversed this improvement, leading to an increase of 30% in student illness (p < 0.0005 and Cohen's d = 0.47. The 10:00 a.m. start was associated with a 12% increase in the value-added number of students making good academic progress (in standard national examinations that was significant (<0.0005 and equivalent to 20% of the national benchmark. These results show that changing to a 10:00 a.m. high school start time can greatly reduce illness and improve academic performance. Implementing school start times later than 8:30 a.m., which may address the circadian delay in adolescents' sleep rhythms more effectively for evening chronotypes, appears to have few costs and substantial benefits.

Radiation dose, driving performance, and cognitive function in patients with head and neck cancer

International Nuclear Information System (INIS)

Yuen, Hon K.; Sharma, Anand K.; Logan, William C.; Gillespie, M. Boyd; Day, Terry A.; Brooks, Johnell O.

2008-01-01

Seven head and neck cancer patients participated in a driving evaluation in a driving simulator. Radiation dose on the temporal lobes was moderately associated with time to complete a cognitive test and with driving performance. Results indicated that incidental irradiation may contribute to a decrease in cognition and in unsafe driving performance, which seems to be time-dependent

Relationships among head posture, pain intensity, disability and deep cervical flexor muscle performance in subjects with postural neck pain

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Arun V. Subbarayalu, PhD

2017-12-01

Full Text Available Objectives: Information Technology (IT professionals working with computers gradually develop forward head posture and, as a result, these professionals are susceptible to several neck disorders. This study intended to reveal the relationships between pain intensity, disability, head posture and deep cervical flexor (DCF muscle performance in patients with postural neck pain. Methods: A cross-sectional study was conducted on 84 IT professionals who were diagnosed with postural neck pain. The participants were recruited with a random sampling approach. A Visual Analogue Scale (VAS, the Northwick Park Neck Pain Questionnaire (NPQ, the Modified Head Posture Spinal Curvature Instrument (MHPSCI, and the Stabilizer Pressure Biofeedback Unit were used to measure neck pain intensity, neck disability, head posture, and DCF muscle performance, respectively. Results: The Pearson correlation coefficient revealed a significantly strong positive relationship between the VAS and the NPQ (r = 0.734. The cranio-vertebral (CV angle was found to have a significantly negative correlation with the VAS (r = −0.536 and a weak negative correlation with the NPQ (r = −0.389. Conclusion: This study concluded that a smaller CV angle corresponded to greater neck pain intensity and disability. Furthermore, there is no significant relationship between CV angle and DCF muscle performance, indicating that head posture re-education through postural correction exercises would not completely correct the motor control deficits in DCF muscles. In addition, a suitable exercise regimen that exclusively targets the deep cervical flexor muscle to improve its endurance is warranted. Keywords: Craniovertebral angle, Disability deep cervical flexors muscle performance, Head posture, Postural neck pain

Experiment on performance of upper head injection system with ROSA-II

International Nuclear Information System (INIS)

1978-05-01

Of the total 10 ROSA-II/UHI performance tests, 6 were reported previously. The rest are presented and discussion is made on the effects of heat generation in the core and UHI injection and repeatability of experiments. In addition, the following are described: (1) Pressure spikes observed in the upper head after sudden stoppage of UHI injection, and (2) discharge flow oscillation possibly due to UHI water injection into the upper plenum. (auth.)

Teachers' dispositional mindfulness and the quality of their relationships with children in Head Start classrooms.

Science.gov (United States)

Becker, Brandon D; Gallagher, Kathleen C; Whitaker, Robert C

2017-12-01

The quality of teachers' relationships with children is a key predictor of children's later social emotional competence and academic achievement. Interventions to increase mindfulness among teachers have focused primarily on the impacts on teachers' subjective well-being, but not on the quality of their relationships with children. Furthermore, none of these interventions have involved preschool teachers. To consider the potential of mindfulness-based interventions to improve the quality of teachers' relationships with preschool-aged children, we examined data from an online survey of 1001 classroom teachers in 37 Pennsylvania Head Start Programs. Using path analysis we investigated the association between teachers' dispositional mindfulness and the quality of their relationships with children (conflict and closeness). We further examined whether this association was mediated by teacher depressive symptoms and moderated by perceived workplace stress. Higher levels of dispositional mindfulness among teachers were associated with higher quality relationships with children (less conflict and greater closeness). The association between greater dispositional mindfulness and less conflict was partially mediated by lower depressive symptoms, and the conditional direct effect of mindfulness on conflict was stronger when perceived workplace stress was lower. These findings suggest that preschool teachers who have higher levels of dispositional mindfulness may experience higher quality relationships with children in their classrooms. Interventions to increase levels of dispositional mindfulness among early childhood educators may improve their well-being along with the quality of their relationships with children, potentially impacting children's educational outcomes. The potential impacts of such interventions may be even stronger if structural and systemic changes are also made to reduce workplace stress. Copyright © 2017 Society for the Study of School Psychology

Relations Between Lower Body Isometric Muscle Force Characteristics and Start Performance in Elite Male Sprint Swimmers

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Igor Beretić

2013-12-01

Full Text Available The aim of the present study was twofold. The first aim was to examine the influence of absolute and relative lower body muscle force on kinematic component which determine the start performance. The second aim was to create multiregressional model which could use as a tool for swimming coaches with the purpose to start performance control and improvement. Twenty seven high-level trained male competitive swimmers all members of the Serbian National Youth and Senior Swimming Team (Age = 21.1 ± 4.3 yrs., Height = 1. 89 ± 0.10 m, Weight = 81.6 ± 8.4 kg, 50m freestyle - long course = 24.36 ± 0.86 s performed two trials of standing leg extensors isometric muscle force testing and three swimming start trials corresponding to 10m distance. The average start time significantly correlated with variables of leg extensors maximum voluntary force (Fmax, r = -0.559, p = 0.002, leg extensors relative muscle voluntary force (Frel, r = -0.727, p < 0.001, leg extensors specific rate of force development (RFD50%, r = -0.338, p = 0.047 and leg extensors relative value of specific rate of force development (RFD50%rel, r = -0.402, p = 0.040. Regression equation for t10m prediction was defined by following variables: maximum voluntary isometric force of leg extensors muscles at absolute and relative level (Fmax and Frel, as well as a specific rate of force development of the same muscle groups (RFD50% and RFD50%rel at absolute and relative level too with 74.4% of explained variance. Contractile abilities indicators of the leg extensors muscles included consideration: Fmax, RFD50%, Frel and RFD50%rel showed significant correlation with swimming start times on 10m. Additionally, the results suggest that swimmers, who possess greater isometric maximum force and specific rate of force development at absolute and relative levels, tend to be able to swim faster on initial 10m swim start perforamnce.

Using Student-Produced Video to Validate Head-to-Toe Assessment Performance.

Science.gov (United States)

Purpora, Christina; Prion, Susan

2018-03-01

This study explored third-semester baccalaureate nursing students' perceptions of the value of using student-produced video as an approach for learning head-to-toe assessment, an essential clinical nursing skill taught in the classroom. A cognitive apprenticeship model guided the study. The researchers developed a 34-item survey. A convenience sample of 72 students enrolled in an applied assessment and nursing fundamentals course at a university in the western United States provided the data. Most students reported a videotaping process that worked, supportive faculty, valuable faculty review of their work, confidence, a sense of performance independence, the ability to identify normal assessment findings, and few barriers to learning. The results suggested that a student-produced video approach to learning head-to-toe assessment was effective. Further, the study demonstrated how to leverage available instructional technology to provide meaningful, personalized instruction and feedback to students about an essential nursing skill. [J Nurs Educ. 2018;57(3):154-158.]. Copyright 2018, SLACK Incorporated.

HOME VISIT QUALITY VARIATIONS IN TWO EARLY HEAD START PROGRAMS IN RELATION TO PARENTING AND CHILD VOCABULARY OUTCOMES.

Science.gov (United States)

Roggman, Lori A; Cook, Gina A; Innocenti, Mark S; Jump Norman, Vonda; Boyce, Lisa K; Christiansen, Katie; Peterson, Carla A

2016-05-01

Home-visiting programs aiming to improve early child development have demonstrated positive outcomes, but processes within home visits to individual families are rarely documented. We examined family-level variations in the home-visiting process (N = 71) from extant video recordings of home visits in two Early Head Start programs, using an observational measure of research-based quality indicators of home-visiting practices and family engagement, the Home Visit Rating Scales (HOVRS). HOVRS scores, showing good interrater agreement and internal consistency, were significantly associated with parent- and staff-reported positive characteristics of home visiting as well as with parenting and child language outcomes tested at program exit. When home-visiting processes were higher quality during the program, home visit content was more focused on child development, families were more involved in the overall program, and most important, scores on measures of the parenting environment and children's vocabulary were higher at the end of the program. Results showed that home visit quality was indirectly associated with child language outcomes through parenting outcomes. Observation ratings of home visit quality could be useful for guiding program improvement, supporting professional development, and increasing our understanding of the links between home-visiting processes and outcomes. © 2016 Michigan Association for Infant Mental Health.

Coccidiosis and performance in broilers with anticoccidial medicated feed starting at different ages

Directory of Open Access Journals (Sweden)

Costa C.A.F.

2000-01-01

Full Text Available The effects of age, litter reutilization, and anticoccidial programs were studied in broilers. The oocyst counts increased with litter reutilization up to third use, and T1 (no anticoccidial drug over the entire 42-day-period and T4 (anticoccidial medication starting from the first day showed the highest counts. The scores for Eimeria acervulina increased up to third use of litter and declined by the fourth use. The scores for E. maxima increased from first to second litter use, and from this to third and fourth use. The scores for E. tenella increased from first and second litter use to third litter use, and declined on fourth use. With high coccidial contamination, as in third use litter, the anticoccidial medication starting from the 1st, 7th (T3 and 14th (T2 day of age presented similar results of lesion scores and average weight gain. When coccidial contamination was low or moderate, as in first, second and fourth use litter, the anticoccidial medication starting at 14 days of age tended to result in a better broiler performance. These data suggest that, with low coccidial challenge, as in broilers raised in first use litter and in farms with single bird age, the delayed anticoccidial medication may provide advantages over the full medication starting from the first day of age.

Axis of eye rotation changes with head-pitch orientation during head impulses about earth-vertical.

Science.gov (United States)

Migliaccio, Americo A; Schubert, Michael C; Clendaniel, Richard A; Carey, John P; Della Santina, Charles C; Minor, Lloyd B; Zee, David S

2006-06-01

The goal of this study was to assess how the axis of head rotation, Listing's law, and eye position influence the axis of eye rotation during brief, rapid head rotations. We specifically asked how the axis of eye rotation during the initial angular vestibuloocular reflex (VOR) changed when the pitch orientation of the head relative to Earth-vertical was varied, but the initial position of the eye in the orbit and the orientation of Listing's plane with respect to the head were fixed. We measured three-dimensional eye and head rotation axes in eight normal humans using the search coil technique during head-and-trunk (whole-body) and head-on-trunk (head-only) "impulses" about an Earth-vertical axis. The head was initially oriented at one of five pitch angles (30 degrees nose down, 15 degrees nose down, 0 degrees, 15 degrees nose up, 30 degrees nose up). The fixation target was always aligned with the nasooccipital axis. Whole-body impulses were passive, unpredictable, manual, rotations with peak-amplitude of approximately 20 degrees , peak-velocity of approximately 80 degrees /s, and peak-acceleration of approximately 1000 degrees /s2. Head-only impulses were also passive, unpredictable, manual, rotations with peak-amplitude of approximately 20 degrees , peak-velocity of approximately 150 degrees /s, and peak-acceleration of approximately 3000 degrees /s2. During whole-body impulses, the axis of eye rotation tilted in the same direction, and by an amount proportional (0.51 +/- 0.09), to the starting pitch head orientation (P rotation could be predicted from vectorial summation of the gains (eye velocity/head velocity) obtained for rotations about the pure yaw and roll head axes. Thus, even when the orientation of Listing's plane and eye position in the orbit are fixed, the axis of eye rotation during the VOR reflects a compromise between the requirements of Listing's law and a perfectly compensatory VOR.

Investigations on self-starting and performance characteristics of simple H and hybrid H-Savonius vertical axis wind rotors

International Nuclear Information System (INIS)

Bhuyan, S.; Biswas, A.

2014-01-01

Highlights: • Hybrid H-Savonius vertical axis wind rotor for built-in environmental wind speeds. • Self-starting characteristics of unsymmetrical H-rotor and Hybrid H-Savonius rotor. • Comparisons between unsymmetrical H-rotor and Hybrid rotor at same experimental conditions. • Insight of the performances of optimum hybrid H-Savonius rotor. • Higher power performance of the optimum rotor compared with some existing VAWT rotors. - Abstract: With recent surge in fossil fuel prices and demands for renewable energy sources, vertical axis wind turbine (VAWT) technologies have emerged out as one of the prime growing sector for small-scale power generation in the built environment. In such an environment, self-starting and high performances are of utmost importance. Amongst all VAWT designs, H-rotor, being a lift-driven device, exhibits a high power coefficient. However, it suffers from poor starting behavior due to its conventional symmetrical NACA airfoil blades. The objective of the present study is to design a VAWT rotor that possesses both self-starting and high power coefficient simultaneously. For this, a three bladed H-rotor with unsymmetrical cambered S818 airfoil blades is investigated, which shows self-starting characteristics at many of the azimuthal angles. However to make the rotor completely self-starting, the same H-rotor is incorporated in a hybrid system with Savonius rotor as its starter. It is found that the hybrid design fully exhibits self-starting capability at all azimuthal positions, signified by the positive static torque coefficient values. For improving power performance of the hybrid rotor, the same is subjected to rigorous experimentations on the wind tunnel at different Reynolds numbers (Re) between 1.44 × 10 5 and 2.31 × 10 5 for five different overlap conditions in the Savonius rotor part. The performance coefficients of the hybrid rotor are compared with the simple H-rotor. Out of all the designs investigated, the maximum Cp

Investigations of internal turbulent flows in a low-head tubular pump and its performance predictions

International Nuclear Information System (INIS)

Tang, X L; Chen, X S; Wang, F J; Yang, W; Wu, Y L

2012-01-01

Based on the RANS equations, standard k−ε turbulence model and SIMPLE algorithm, the internal turbulent flows in a low-head tubular pump were simulated by using the FLUENT software. Based on the predicted flow fields, the external performance curves including the head-discharge, efficiency-discharge and power-discharge curves were further obtained. The calculated results indicate that the internal flow pattern is smooth at the best efficiency point (BEP). When it works under off-design operating cases, the flow pattern inside the diffuser and the discharge passage is disorder, and at the same time, the hydraulic losses mainly come from the secondary flows. At large flow rates, the minimum static pressure near the inlet of the blade pressure surfaces due to the negative attack angle. At small flow rates, the minimum value happens near the inlet of the suction surfaces. At the BEP, the lowest static pressure appears in the region behind the suction surfaces inlet. The newly-designed model is validated by the comparisons between its predicted external performance and the experimental data of the JGM-3 model. This research provides some important references for the optimization of a low-head tubular pump.

Heading-vector navigation based on head-direction cells and path integration.

Science.gov (United States)

Kubie, John L; Fenton, André A

2009-05-01

Insect navigation is guided by heading vectors that are computed by path integration. Mammalian navigation models, on the other hand, are typically based on map-like place representations provided by hippocampal place cells. Such models compute optimal routes as a continuous series of locations that connect the current location to a goal. We propose a "heading-vector" model in which head-direction cells or their derivatives serve both as key elements in constructing the optimal route and as the straight-line guidance during route execution. The model is based on a memory structure termed the "shortcut matrix," which is constructed during the initial exploration of an environment when a set of shortcut vectors between sequential pairs of visited waypoint locations is stored. A mechanism is proposed for calculating and storing these vectors that relies on a hypothesized cell type termed an "accumulating head-direction cell." Following exploration, shortcut vectors connecting all pairs of waypoint locations are computed by vector arithmetic and stored in the shortcut matrix. On re-entry, when local view or place representations query the shortcut matrix with a current waypoint and goal, a shortcut trajectory is retrieved. Since the trajectory direction is in head-direction compass coordinates, navigation is accomplished by tracking the firing of head-direction cells that are tuned to the heading angle. Section 1 of the manuscript describes the properties of accumulating head-direction cells. It then shows how accumulating head-direction cells can store local vectors and perform vector arithmetic to perform path-integration-based homing. Section 2 describes the construction and use of the shortcut matrix for computing direct paths between any pair of locations that have been registered in the shortcut matrix. In the discussion, we analyze the advantages of heading-based navigation over map-based navigation. Finally, we survey behavioral evidence that nonhippocampal

Eye-Head Coordination in 31 Space Shuttle Astronauts during Visual Target Acquisition.

Science.gov (United States)

Reschke, Millard F; Kolev, Ognyan I; Clément, Gilles

2017-10-27

Between 1989 and 1995, NASA evaluated how increases in flight duration of up to 17 days affected the health and performance of Space Shuttle astronauts. Thirty-one Space Shuttle pilots participating in 17 space missions were tested at 3 different times before flight and 3 different times after flight, starting within a few hours of return to Earth. The astronauts moved their head and eyes as quickly as possible from the central fixation point to a specified target located 20°, 30°, or 60° off center. Eye movements were measured with electro-oculography (EOG). Head movements were measured with a triaxial rate sensor system mounted on a headband. The mean time to visually acquire the targets immediately after landing was 7-10% (30-34 ms) slower than mean preflight values, but results returned to baseline after 48 hours. This increase in gaze latency was due to a decrease in velocity and amplitude of both the eye saccade and head movement toward the target. Results were similar after all space missions, regardless of length.

Radial head button holing: a cause of irreducible anterior radial head dislocation

Energy Technology Data Exchange (ETDEWEB)

Shin, Su-Mi; Chai, Jee Won; You, Ja Yeon; Park, Jina [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Bae, Kee Jeong [Seoul National University Seoul Metropolitan Government Boramae Medical Center, Department of Orthopedic Surgery, Seoul (Korea, Republic of)

2016-10-15

''Buttonholing'' of the radial head through the anterior joint capsule is a known cause of irreducible anterior radial head dislocation associated with Monteggia injuries in pediatric patients. To the best of our knowledge, no report has described an injury consisting of buttonholing of the radial head through the annular ligament and a simultaneous radial head fracture in an adolescent. In the present case, the radiographic findings were a radial head fracture with anterior dislocation and lack of the anterior fat pad sign. Magnetic resonance imaging (MRI) clearly demonstrated anterior dislocation of the fractured radial head through the torn annular ligament. The anterior joint capsule and proximal portion of the annular ligament were interposed between the radial head and capitellum, preventing closed reduction of the radial head. Familiarity with this condition and imaging findings will aid clinicians to make a proper diagnosis and fast decision to perform an open reduction. (orig.)

Efficacy and safety of chemoradiotherapy when performed by head and neck surgeon

International Nuclear Information System (INIS)

Matsuura, Kazuto; Sagai, Shun; Katagiri, Katsunori; Imai, Takayuki; Ishida, Eiichi; Saijo, Shigeru; Shiga, Kiyoto

2011-01-01

Concurrent chemoradiotherapy (CCRT) has been recognized as a standard treatment for the local advanced SCCHN. We perform 40-50 CCRT annually during operations on more than 230 patients in our division. CCRT with high-dose single-agent cisplatin is now the standard of care for nonsurgical treatment for local advanced SCCHN. We use a similar method for eligible cases. All patients were able to receive the full dose of radiotherapy (70 Gy) and completed at least two courses chemotherapy. We were able to perform this regimen with sufficient supportive care. This regimen is feasible for the treatment of Japanese patients with SCCHN, and does not require the modification of the treatment plan to account for racial differences. The introduction of this regimen is expected in the future in many other institutions in Japan. The new CCRT menu has been made by prospective clinical studies and requires a multicenter study. It is necessary to give an opinion from a surgical viewpoint with respect to the structure of the protocol and such matters to clinical oncologists who are expert in protocol formation. Head and neck surgeons constitute the treatment team for patients with head and neck cancer and should control the treatment plan. (author)

The effect of Early Head Start on child welfare system involvement: A first look at longitudinal child maltreatment outcomes☆

Science.gov (United States)

Green, Beth L.; Ayoub, Catherine; Bartlett, Jessica Dym; Von Ende, Adam; Furrer, Carrie; Chazan-Cohen, Rachel; Vallotton, Claire; Klevens, Joanne

2015-01-01

The high societal and personal costs of child maltreatment make identification of effective early prevention programs a high research priority. Early Head Start (EHS), a dual generational program serving low-income families with children prenatally through age three years, is one of the largest federally funded programs for infants and toddlers in the United States. A national randomized trial found EHS to be effective in improving parent and child outcomes, but its effectiveness in reducing child maltreatment was not assessed. The current study used administrative data from state child welfare agencies to examine the impact of EHS on documented abuse and neglect among children from seven of the original seventeen programs in the national EHS randomized controlled trial. Results indicated that children in EHS had significantly fewer child welfare encounters between the ages of five and nine years than did children in the control group, and that EHS slowed the rate of subsequent encounters. Additionally, compared to children in the control group, children in EHS were less likely to have a substantiated report of physical or sexual abuse, but more likely to have a substantiated report of neglect. These findings suggest that EHS may be effective in reducing child maltreatment among low-income children, in particular, physical and sexual abuse. PMID:26744550

[Can the prophylactic treatment of mycotic mucositis improve the time of performing radiotherapy in head and neck tumors?].

Science.gov (United States)

Gava, A; Ferrarese, F; Tonetto, V; Coghetto, F; Marazzato, G; Zorat, P L

1996-04-01

Radiotherapy-related mucositis is the most frequent complication in the patients submitted to irradiation for head and neck cancers. Many such patients may develop mycotic infections which may lead to treatment discontinuation, with possible consequences on the local control of these cancers. In this study, we investigated the efficacy of fluconazole in preventing mycotic mucositis in 80 patients undergoing radiation therapy for head and neck cancers. The patients were randomized to two groups: 41 patients in group A received the supporting treatment we usually administer, plus fluconazole (50 mg/day) starting from the 6th irradiation session throughout the treatment; 39 patients in group B received the same baseline treatment, but were given the drug only when mycotic infections appeared. The clinical characteristics, treated sites, treatment doses and volumes were similar in the two groups of patients. Fluconazole was well tolerated and no early or late toxicity was observed. We had 1 mycotic mucositis and 14 non-scheduled treatment discontinuations in group A, vs. 19 and 30, respectively, in group B. Radiation therapy lasted 52.3 days (mean) in group A and 55.6 days (mean) in group B; the differences were statistically significant. In our experience, fluconazole, used prophylactically from the 6th radiotherapy session on, reduced the number of mycotic infections and improved radiotherapy schedule in our head and neck cancer patients.

Coordination of head movements and speech in first encounter dialogues

DEFF Research Database (Denmark)

Paggio, Patrizia

2015-01-01

This paper presents an analysis of the temporal alignment be- tween head movements and associated speech segments in the NOMCO corpus of first encounter dialogues [1]. Our results show that head movements tend to start slightly before the onset of the corresponding speech sequence and to end...... slightly after, but also that there are delays in both directions in the range of -/+ 1s. Various factors that may influence delay duration are investigated. Correlations are found between delay length and the duration of the speech sequences associated with the head movements. Effects due to the different...

GPK heading machine

Energy Technology Data Exchange (ETDEWEB)

Krmasek, J.; Novosad, K.

1981-01-01

This article evaluates performance tests of the Soviet made GPK heading machine carried out in 4 coal mines in Czechoslovakia (Ostrava-Karvina region and Kladno mines). GPK works in coal seams and rocks with compression strength of 40 to 50 MPa. Dimensions of the tunnel are height 1.8 to 3.8 m and width 2.6 to 4.7 m, tunnel gradient plus to minus 10 degrees. GPK weighs 16 t, its conical shaped cutting head equipped with RKS-1 cutting tools is driven by an electric motor with 55 kW capacity. Undercarriage of the GPK, gathering-arm loader, hydraulic system, electric system and dust supression system (water spraying or pneumatic section) are characterized. Specifications of GPK heading machines are compared with PK-3r and F8 heading machines. Reliability, number of failures, dust level, noise, productivity depending on compression strength of rocks, heading rate in coal and in rocks, energy consumption, performance in inclined tunnels, and cutting tool wear are evaluated. Tests show that GPK can be used to drive tunnels in coal with rock constituting up to 50% of the tunnel crosscut, as long as rock compression strength does not exceed 50 MPa. In rocks characterized by higher compression strength cutting tool wear sharply increases. GPK is characterized by higher productivity than that of the PK-3r heading machine. Among the weak points of the GPK are: unsatisfactory reliability and excessive wear of its elements. (4 refs.) (In Czech)

Effects of residential instability on Head Start children and their relationships with older siblings: influences of child emotionality and conflict between family caregivers.

Science.gov (United States)

Stoneman, Z; Brody, G H; Churchill, S L; Winn, L L

1999-01-01

This study examined the influence that residential dislocations have on child behavior problems, depression, peer competence, cognitive competence, and the quality of sibling relations in a sample of 70 Head Start children, aged 32 to 67 months, and their older brothers and sisters, aged 48 to 155 months. This was the first study to investigate the sibling relationship in the context of high residential mobility. Information on child characteristics was obtained from mothers and teachers. Sibling data (warmth/harmony and conflict) were obtained from coding videotaped interactions. Child emotionality was found to be an important moderator of the effects of residential mobility on young, poor children and their siblings; caregiver conflict was a less powerful moderator of these effects. Residential instability seemed to compromise the warmth/harmony of the sibling relationship. It was concluded that the effects of residential instability are complex and cannot be understood without considering child characteristics, such as temperament, and the family context in which the child lives.

Parasitic outbreak of the copepod Balaenophilus manatorum in neonate loggerhead sea turtles (Caretta caretta) from a head-starting program.

Science.gov (United States)

Crespo-Picazo, J L; García-Parraga, D; Domènech, F; Tomás, J; Aznar, F J; Ortega, J; Corpa, J M

2017-06-02

Diseases associated to external parasitosis are scarcely reported in sea turtles. During the last decades several organism have been documented as a part of normal epibiont community connected to sea turtles. The copepod Balaenophilus manatorum has been cited as a part of epibiont fauna with some concern about its parasitic capacity. This study serves three purposes, i.e. (i) it sheds light on the type of life style that B. manatorum has developed with its hosts, particularly turtles; (ii) it makes a cautionary note of the potential health risks associated with B. manatorum in sea turtles under captivity conditions and in the wild, and (iii) it provides data on effective treatments against B. manatorum. We report for the first time a massive infestation of the copepod B. manatorum and subsequent acute mortality in a group of loggerhead sea turtle hatchlings. Four-month-old turtles from a head-starting program started exhibiting excitatory and fin rubbing behavior preceding an acute onset of lethargy, skin ulceration and death in some animals. All the individuals (n = 57) were affected by severe copepod load and presented different degrees of external macroscopic skin lesions. The ventral area of front flippers, axillar and pericloacal skin were mostly affected, and were the main parasite distribution regions. Copepods were also detected on plastron and carapace sutures. The gut contents of B. manatorum reacted positively for cytokeratin, indicating consumption of turtle skin. Severe ulcerative necrotic dermatitis and large amount of bacteria presence were the major histopathological findings. Individual fresh water immersion for 10 min and lufenuron administration (0.1 ppm) to the water system every 2 weeks proved effective for removing turtle parasites and to control re-infestation, respectively. The results from our study clearly indicated that B. manatorum individuals consume turtle skin. The pathological effects of this agent and the potential implications

New strategy for the optimal design and manufacture of high performance milling heads

Directory of Open Access Journals (Sweden)

Bustillo, A.

2011-12-01

Full Text Available High-performance mechanical-transmission heads are one of the most complex, costly and problematic parts of a milling machine, owing to the large amount of piping required for transporting fluids and to the high level of mechanical performance that is required from them. This study proposes a strategy for optimising the design and manufacture of head bodies by using aluminium alloys and by integrating tubular stainless steel inserts in the casting of the head. These tubular inserts that are integrated into the aluminium mass are an alternative to cooling conduits currently made by machine drilling. As demonstrated in the experimental validation of the first prototype, the new method has created a design that retains the same mechanical performance, increases its reliability and reduces the weight of the milling machine’s moving parts.

Los cabezales de transmisión mecánica de altas prestaciones son una de las partes más complejas, costosas y problemáticas de una maquina fresadora. Esto es debido a la gran cantidad de canalizaciones para la transmisión de fluidos que deben de contener y a las altas prestaciones mecánicas que se les exigen. En este trabajo se presenta una estrategia para optimizar el diseño y la fabricación de los cuerpos de estos cabezales basada en la incorporación de aleaciones de aluminio y la inclusión de insertos tubulares de acero en la propia fundición que conforma el cabezal. Los insertos tubulares sustituyen a los canales de refrigeración realizados actualmente por taladros de mecanizado y quedan integrados en la masa de aluminio. La nueva metodología ha permitido realizar un diseño que mantiene las prestaciones mecánicas, aumenta la fiabilidad y reduce la masa de estos elementos móviles de fresadoras como ha demostrado la validación experimental de un primer prototipo.

General Anesthesia Versus Conscious Sedation in Acute Stroke Treatment: The Importance of Head Immobilization

Energy Technology Data Exchange (ETDEWEB)

Janssen, H., E-mail: hendrik.janssen@med.uni-muenchen.de [Ludwig-Maximilians-University Hospital, Department of Neuroradiology (Germany); Buchholz, G. [Ludwig-Maximilians-University Hospital, Department of Neurology (Germany); Killer, M. [Paracelsus Medical University, Neurology/Research Institute of Neurointervention (Austria); Ertl, L.; Brückmann, H. [Ludwig-Maximilians-University Hospital, Department of Neuroradiology (Germany); Lutz, J. [Ingolstadt Hospital, Department of Neuroradiology (Germany)

2016-09-15

PurposeWhile today mechanical thrombectomy is an established treatment option for main branch occlusions in anterior circulation stroke, there is still an ongoing debate on the kind of anesthesia to be preferred. Introducing a simple method for head stabilization, we analyzed safety and duration of endovascular recanalization procedures under general anesthesia (GA) and conscious sedation (CS).MethodsWe retrospectively identified 84 consecutive patients who underwent mechanical thrombectomy owing to acute anterior circulation stroke. Fifty-three were treated under GA and 31 under CS equipped with a standard cervical collar to reduce head movement. We evaluated recanalization results, in-house time to start recanalization, procedure times, technical and clinical complication rates, and conversion rates from CS to GA.ResultsRecanalization of mTICI ≥2b was achieved in 80 % under CS and in 81 % under GA. Median in-house time to start recanalization for CS was 60 min (IQR 28; 44–72) and 77 min (IQR 23; 68–91) for GA (P = 0.001). Median procedure time under CS was 35 min (IQR 43; 69–25) and 41 min (IQR 43; 66–23) for GA (P = 0.9). No major complications such as ICH occurred in either group, and no conversions from CS to GA were necessary.ConclusionMechanical thrombectomy can be performed faster and safely under CS in combination with simple head immobilization using a standard cervical collar.

General Anesthesia Versus Conscious Sedation in Acute Stroke Treatment: The Importance of Head Immobilization

International Nuclear Information System (INIS)

Janssen, H.; Buchholz, G.; Killer, M.; Ertl, L.; Brückmann, H.; Lutz, J.

2016-01-01

PurposeWhile today mechanical thrombectomy is an established treatment option for main branch occlusions in anterior circulation stroke, there is still an ongoing debate on the kind of anesthesia to be preferred. Introducing a simple method for head stabilization, we analyzed safety and duration of endovascular recanalization procedures under general anesthesia (GA) and conscious sedation (CS).MethodsWe retrospectively identified 84 consecutive patients who underwent mechanical thrombectomy owing to acute anterior circulation stroke. Fifty-three were treated under GA and 31 under CS equipped with a standard cervical collar to reduce head movement. We evaluated recanalization results, in-house time to start recanalization, procedure times, technical and clinical complication rates, and conversion rates from CS to GA.ResultsRecanalization of mTICI ≥2b was achieved in 80 % under CS and in 81 % under GA. Median in-house time to start recanalization for CS was 60 min (IQR 28; 44–72) and 77 min (IQR 23; 68–91) for GA (P = 0.001). Median procedure time under CS was 35 min (IQR 43; 69–25) and 41 min (IQR 43; 66–23) for GA (P = 0.9). No major complications such as ICH occurred in either group, and no conversions from CS to GA were necessary.ConclusionMechanical thrombectomy can be performed faster and safely under CS in combination with simple head immobilization using a standard cervical collar.

Brush head composition, wear profile, and cleaning efficacy: an assessment of three electric brush heads using in vitro methods.

Science.gov (United States)

Kaiser, Eva; Meyners, Michael; Markgraf, Dirk; Stoerkel, Ulrich; von Koppenfels, Roxana; Adam, Ralf; Soukup, Martin; Wehrbein, Heinrich; Erbe, Christina

2014-01-01

The objective of this research was to evaluate a current store brand (SB) brush head for composition/physical characteristics, Wear Index (WI), and cleaning efficacy versus the previous SB brush head refill design (SB control) and the Oral-B Precision Clean brush head (positive control, PC). This research consisted of three parts: 1) Analytical analysis using Fourier Transform Infrared (FT-IR) spectrometry to evaluate the chemical composition of the current SB brush head bristles relative to the SB control. In addition, physical parameters such as bristle count and diameter were determined. 2) Wear Index (WI) investigation to determine the Wear Index scores of in vitro-aged brush heads at four weeks (one month) and 13 weeks (three months) by a trained investigator. To "age" the brush heads, a robot system was used as a new alternative in vitro method to simulate aging by consumer use. 3) Robot testing to determine the cleaning performance of in vitro-aged brush heads, comparing one month-aged current SB brush heads with the SB control (one and three months-aged) and the PC brush heads (three months-aged) in a standardized fashion. 1) FT-IR analysis revealed that the chemical composition of the current and control SB refill brush heads is identical. In terms of physical parameters, the current SB brush head has 12% more bristles and a slightly oval brush head compared to the round brush head of the SB control. 2) Wear Index analysis showed there was no difference in the one month-aged current SB brush head versus the one month-aged SB control (1.67 vs. 1.50, p = 0.65) or versus the three months-aged PC brush head (1.67 vs. 1.50, p = 0.65). The one month-aged current SB brush head demonstrated statistically significantly less wear than the three months-aged SB control (1.67 vs. 2.67, p = 0.01). 3) Analysis of cleaning efficacy shows that the one month-aged current SB brush head had improved cleaning performance over the one month-aged SB control brush head (p < 0

Modeling and nonlinear heading control for sailing yachts

DEFF Research Database (Denmark)

Xiao, Lin; Jouffroy, Jerome

2011-01-01

This paper presents a study on the development and testing of a model-based heading controller for a sailing yacht. Using Fossen's compact notation for marine vehicles, we first describe a nonlinear 4-DOF dynamic model for a sailing yacht, including roll. Starting from this model, we then design...

Effects of Head Size on the Performance of Twist-Off Bolts

OpenAIRE

Schnupp, Keith Otto

2003-01-01

This study examines a specific application of button-head type twist-off bolts. Currently, the Research Council on Structural Connections Specification (2000) removes the requirement for ASTM F436 washers (ASTM 2000a) under the bolt head of twist-off bolts where the head diameter equals or exceeds that of an ASTM F436 washer when oversized and slotted holes are used. The need for washers is also removed for A490 strength bolts used on steels with specified yield strengths less than 40 ksi p...

Barriers and motivators to reducing secondhand smoke exposure in African American families of head start children: a qualitative study.

Science.gov (United States)

Hoehn, Jessica L; Riekert, Kristin A; Borrelli, Belinda; Rand, Cynthia S; Eakin, Michelle N

2016-08-01

To identify barriers and motivators for reducing secondhand smoke exposure (SHSe) for families of African-American, low-income, urban children. Audiotaped intervention sessions of 52 African-American caregivers of Head Start children who reported being a smoker and/or had at least one smoker in the home were randomly sampled from a larger trial examining the effectiveness of a motivational-interviewing intervention in reducing child's SHSe. Counseling sessions were qualitatively coded to identify barriers and motivators to implementing a home smoking ban or quitting smoking. African-American families identified several themes that were either or both barriers and motivators for SHSe reduction, including: asking others not to smoke, other family living in the home, neighborhood safety, absence of childcare, cost/availability of cessation tools, physician support and prevention of health problems. Urban, low-income African-American families face numerous barriers to reducing SHSe. Families were able to identify many motivators for reducing SHSe, suggesting an awareness of the importance for SHSe reduction but uncertainty in their confidence to change behaviors. Counseling should include tailoring to be most effective in supporting health behavior change. Greater emphasis on motivators is needed, such as low-cost/free cessation tools, engagement from physicians and greater involvement of extended family members. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

How can parents get involved in preschool? Barriers and engagement in education by ethnic minority parents of children attending Head Start.

Science.gov (United States)

Mendez, Julia L

2010-01-01

An intervention was developed to promote parent involvement with ethnic minority families of children attending Head Start preschool programs. Two hundred eighty-eight predominantly African American families from a small southern city were included in this study. Parent satisfaction with the program was high, yet engagement was less than optimal. Some effects were found for the program, despite low levels of participation. Ethnic minority parents who received the intervention increased the frequency of reading to their child as compared with parents in a comparison group who did not receive the program. The quality of the parent-teacher relationship was significantly correlated with parental participation in the intervention. Program participation and the parent-teacher relationship were correlated with higher levels of children's school readiness abilities. Children in the intervention condition showed stronger end-of-year receptive vocabulary and parent-rated social competence as compared with children who did not receive treatment. This research documents the challenges involved in engaging parents in prevention programs. Strategies for maximizing the benefits of preschool for ethnic minority families and their children are discussed. (c) 2009 APA, all rights reserved.

EXAMINING LONG-TERM EFFECTS OF AN INFANT MENTAL HEALTH HOME-BASED EARLY HEAD START PROGRAM ON FAMILY STRENGTHS AND RESILIENCE.

Science.gov (United States)

Mckelvey, Lorraine; Schiffman, Rachel F; Brophy-Herb, Holly E; Bocknek, Erika London; Fitzgerald, Hiram E; Reischl, Thomas M; Hawver, Shelley; Cunningham Deluca, Mary

2015-01-01

Infant Mental Health based interventions aim to promote the healthy development of infants and toddlers through promoting healthy family functioning to foster supportive relationships between the young child and his or her important caregivers. This study examined impacts of an Infant Mental Health home-based Early Head Start (IMH-HB EHS) program on family functioning. The sample includes 152 low-income families in the Midwestern United States, expectant or parenting a child younger than 1 year of age, who were randomly assigned to receive IMH-HB EHS services (n = 75) or to a comparison condition (n = 77). Mothers who received IMH-HB EHS services reported healthier psychological and family functioning, outcomes that are consistent with the IMH focus, when their children were between the ages of 3 and 7 years of age. Specifically, mothers in the IMH-HB EHS group reported healthier family functioning and relationships, better coping skills needed to advocate for their families, and less stress in the parenting role versus those in the comparison condition. The study also examined support seeking coping, some of which changed differently over time based on program group assignment. Overall, findings suggest that the gains families achieve from participating in IMH-HB EHS services are maintained after services cease. © 2015 Michigan Association for Infant Mental Health.

Smart or Diverse Start-up Teams?

DEFF Research Database (Denmark)

Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

2017-01-01

This paper explores the relationship between cognitive abilities and team performance in a start-up setting. We argue that performance in this setting hinges on three tasks: opportunity recognition, problem solving, and implementation. We theorize that cognitive ability at the individual level has...... others can be assigned to tasks that impose a greater cognitive load (problem solving or opportunity recognition). We present the results of a field experiment in which 573 students in 49 teams started up and managed real companies. We ensured exogenous variation in—otherwise random—team composition...... by assigning students to teams based on their measured cognitive abilities. Each team performed a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of start-up teams first increases and then decreases with ability dispersion. Strikingly, average...

Effects of fasting and feeding on the fast-start swimming performance of southern catfish Silurus meridionalis.

Science.gov (United States)

Yan, G J; He, X K; Cao, Z D; Fu, S J

2015-01-21

This study investigated the effects of fasting and feeding on the fast-start escape swimming performance of juvenile southern catfish Silurus meridionalis, a sit-and-wait forager that encounters extreme fasting and famine frequently during its lifespan. Ten to 30 days of fasting resulted in no significant change in most of the variables measured in the fast-start response except a 20-30% decrease in the escape distance during the first 120 ms (D 120ms ) relative to the control group (48 h after feeding). The ratio of the single-bend (SB) response (lower energetic expenditure) to the double-bend (DB) response increased significantly from 0% in the control group to 75 and 82·5% in the 20 and 30 day fasting groups, respectively. Satiated feeding (25% of body mass) resulted in a significantly lower (36·6%) maximum linear velocity (V max ) and a significantly lower (43·3%) D 120ms than in non-fed fish (control group, 48 h after feeding). Half-satiated feeding (12·5% of body mass), however, showed no significant effects on any of the measured variables of the fast-start response relative to control fish. It is suggested that the increase in the ratio of SB:DB responses with fasting in S. meridionalis may reflect a trade-off between energy conservation and maintaining high V max , while variables of fast-start performance were more sensitive to feeding than fasting might be an adaptive strategy to their foraging mode and food availability in their habitat. © 2015 The Fisheries Society of the British Isles.

Experimental Study on the Thermal Start-Up Performance of the Graphene/Water Nanofluid-Enhanced Solar Gravity Heat Pipe.

Science.gov (United States)

Zhao, Shanguo; Xu, Guoying; Wang, Ning; Zhang, Xiaosong

2018-01-28

The solar gravity heat pipe has been widely used for solar thermal water heating because of its high efficient heat transfer and thermal diode characteristics. Operated on fluctuant and low intensity solar radiation conditions, a solar gravity heat pipe may frequently start up. This severely affects its solar collection performance. To enhance the thermal performance of the solar gravity heat pipe, this study proposes using graphene/water nanofluid as the working fluid instead of deionized water. The stability of the prepared graphene/water nanofluid added with PVP was firstly investigated to obtain the optimum mass ratios of the added dispersant. Thermophysical properties-including the thermal conductivity and viscosity-of nanofluid with various graphene nanoplatelets (GNPs) concentrations were measured at different temperatures for further analysis. Furthermore, based on the operational evaluation on a single heat pipe's start-up process, the performance of nanofluid-enhanced solar gravity heat pipes using different concentrations of GNPs were compared by using water heating experiments. Results indicated that the use of 0.05 wt % graphene/water nanofluid instead of water could achieve a 15.1% and 10.7% reduction in start-up time under 30 and 60 W input heating conditions, respectively. Consequently, a higher thermal efficiency for solar collection could be expected.

Experimental Study on the Thermal Start-Up Performance of the Graphene/Water Nanofluid-Enhanced Solar Gravity Heat Pipe

Science.gov (United States)

Zhao, Shanguo; Xu, Guoying; Wang, Ning; Zhang, Xiaosong

2018-01-01

The solar gravity heat pipe has been widely used for solar thermal water heating because of its high efficient heat transfer and thermal diode characteristics. Operated on fluctuant and low intensity solar radiation conditions, a solar gravity heat pipe may frequently start up. This severely affects its solar collection performance. To enhance the thermal performance of the solar gravity heat pipe, this study proposes using graphene/water nanofluid as the working fluid instead of deionized water. The stability of the prepared graphene/water nanofluid added with PVP was firstly investigated to obtain the optimum mass ratios of the added dispersant. Thermophysical properties—including the thermal conductivity and viscosity—of nanofluid with various graphene nanoplatelets (GNPs) concentrations were measured at different temperatures for further analysis. Furthermore, based on the operational evaluation on a single heat pipe’s start-up process, the performance of nanofluid-enhanced solar gravity heat pipes using different concentrations of GNPs were compared by using water heating experiments. Results indicated that the use of 0.05 wt % graphene/water nanofluid instead of water could achieve a 15.1% and 10.7% reduction in start-up time under 30 and 60 W input heating conditions, respectively. Consequently, a higher thermal efficiency for solar collection could be expected. PMID:29382094

Experimental Study on the Thermal Start-Up Performance of the Graphene/Water Nanofluid-Enhanced Solar Gravity Heat Pipe

Directory of Open Access Journals (Sweden)

Shanguo Zhao

2018-01-01

Full Text Available The solar gravity heat pipe has been widely used for solar thermal water heating because of its high efficient heat transfer and thermal diode characteristics. Operated on fluctuant and low intensity solar radiation conditions, a solar gravity heat pipe may frequently start up. This severely affects its solar collection performance. To enhance the thermal performance of the solar gravity heat pipe, this study proposes using graphene/water nanofluid as the working fluid instead of deionized water. The stability of the prepared graphene/water nanofluid added with PVP was firstly investigated to obtain the optimum mass ratios of the added dispersant. Thermophysical properties—including the thermal conductivity and viscosity—of nanofluid with various graphene nanoplatelets (GNPs concentrations were measured at different temperatures for further analysis. Furthermore, based on the operational evaluation on a single heat pipe’s start-up process, the performance of nanofluid-enhanced solar gravity heat pipes using different concentrations of GNPs were compared by using water heating experiments. Results indicated that the use of 0.05 wt % graphene/water nanofluid instead of water could achieve a 15.1% and 10.7% reduction in start-up time under 30 and 60 W input heating conditions, respectively. Consequently, a higher thermal efficiency for solar collection could be expected.

Impact of Biodiesel Blends and Di-Ethyl-Ether on the Cold Starting Performance of a Compression Ignition Engine

Directory of Open Access Journals (Sweden)

Adrian Clenci

2016-04-01

Full Text Available The use of biodiesel fuel in compression ignition engines has the potential to reduce CO2, which can lead to a reduction in global warming and environmental hazards. Biodiesel is an attractive fuel, as it is made from renewable resources. Many studies have been conducted to assess the impact of biodiesel use on engine performances. Most of them were carried out in positive temperature conditions. A major drawback associated with the use of biodiesel, however, is its poor cold flow properties, which have a direct influence on the cold starting performance of the engine. Since diesel engine behavior at negative temperatures is an important quality criterion of the engine’s operation, one goal of this paper is to assess the starting performance at −20 °C of a common automotive compression ignition engine, fueled with different blends of fossil diesel fuel and biodiesel. Results showed that increasing the biodiesel blend ratio generated a great deterioration in engine startability. Another goal of this study was to determine the biodiesel blend ratio limit at which the engine would not start at −20 °C and, subsequently, to investigate the impact of Di-Ethyl-Ether (DEE injection into the intake duct on the engine’s startability, which was found to be recovered.

How network-based incubation helps start-up performance : a systematic review against the background of management theories

NARCIS (Netherlands)

Eveleens, Chris P.|info:eu-repo/dai/nl/369284704; van Rijnsoever, Frank J.|info:eu-repo/dai/nl/314100334; Niesten, Eva M M I

2017-01-01

The literature on how network-based incubation influences the performance of technology-based start-ups has recently grown considerably and provided valuable insights. However, at the same time this literature has become quite fragmented, inconsistently conceptualised, and theoretically

Radiologic head CT interpretation errors in pediatric abusive and non-abusive head trauma patients

International Nuclear Information System (INIS)

Kralik, Stephen F.; Finke, Whitney; Wu, Isaac C.; Ho, Chang Y.; Hibbard, Roberta A.; Hicks, Ralph A.

2017-01-01

Pediatric head trauma, including abusive head trauma, is a significant cause of morbidity and mortality. The purpose of this research was to identify and evaluate radiologic interpretation errors of head CTs performed on abusive and non-abusive pediatric head trauma patients from a community setting referred for a secondary interpretation at a tertiary pediatric hospital. A retrospective search identified 184 patients <5 years of age with head CT for known or potential head trauma who had a primary interpretation performed at a referring community hospital by a board-certified radiologist. Two board-certified fellowship-trained neuroradiologists at an academic pediatric hospital independently interpreted the head CTs, compared their interpretations to determine inter-reader discrepancy rates, and resolved discrepancies to establish a consensus second interpretation. The primary interpretation was compared to the consensus second interpretation using the RADPEER trademark scoring system to determine the primary interpretation-second interpretation overall and major discrepancy rates. MRI and/or surgical findings were used to validate the primary interpretation or second interpretation when possible. The diagnosis of abusive head trauma was made using clinical and imaging data by a child abuse specialist to separate patients into abusive head trauma and non-abusive head trauma groups. Discrepancy rates were compared for both groups. Lastly, primary interpretations and second interpretations were evaluated for discussion of imaging findings concerning for abusive head trauma. There were statistically significant differences between primary interpretation-second interpretation versus inter-reader overall and major discrepancy rates (28% vs. 6%, P=0.0001; 16% vs. 1%, P=0.0001). There were significant differences in the primary interpretation-second interpretation overall and major discrepancy rates for abusive head trauma patients compared to non-abusive head trauma

Radiologic head CT interpretation errors in pediatric abusive and non-abusive head trauma patients

Energy Technology Data Exchange (ETDEWEB)

Kralik, Stephen F.; Finke, Whitney; Wu, Isaac C.; Ho, Chang Y. [Indiana University School of Medicine, Department of Radiology and Imaging Sciences, Indianapolis, IN (United States); Hibbard, Roberta A.; Hicks, Ralph A. [Indiana University School of Medicine, Department of Pediatrics, Section of Child Protection Programs, Indianapolis, IN (United States)

2017-07-15

Pediatric head trauma, including abusive head trauma, is a significant cause of morbidity and mortality. The purpose of this research was to identify and evaluate radiologic interpretation errors of head CTs performed on abusive and non-abusive pediatric head trauma patients from a community setting referred for a secondary interpretation at a tertiary pediatric hospital. A retrospective search identified 184 patients <5 years of age with head CT for known or potential head trauma who had a primary interpretation performed at a referring community hospital by a board-certified radiologist. Two board-certified fellowship-trained neuroradiologists at an academic pediatric hospital independently interpreted the head CTs, compared their interpretations to determine inter-reader discrepancy rates, and resolved discrepancies to establish a consensus second interpretation. The primary interpretation was compared to the consensus second interpretation using the RADPEER trademark scoring system to determine the primary interpretation-second interpretation overall and major discrepancy rates. MRI and/or surgical findings were used to validate the primary interpretation or second interpretation when possible. The diagnosis of abusive head trauma was made using clinical and imaging data by a child abuse specialist to separate patients into abusive head trauma and non-abusive head trauma groups. Discrepancy rates were compared for both groups. Lastly, primary interpretations and second interpretations were evaluated for discussion of imaging findings concerning for abusive head trauma. There were statistically significant differences between primary interpretation-second interpretation versus inter-reader overall and major discrepancy rates (28% vs. 6%, P=0.0001; 16% vs. 1%, P=0.0001). There were significant differences in the primary interpretation-second interpretation overall and major discrepancy rates for abusive head trauma patients compared to non-abusive head trauma

Improvement in motor performance during high pressure pump starting at NDDP, Kalpakkam

International Nuclear Information System (INIS)

Nagaraj, R.; Murugan, V.; Thalor, K.L.; Saxena, A.K.; Dangore, A.Y.; Prabhakar, S.; Tiwari, P.K.

2007-01-01

The major energy requirement required for a Sea Water Reverse Osmosis is in the form of Electrical Energy. The primary energy requirement in the process is the electrical energy fed to High Pressure Pumps to pressurize the feed sea water to membranes. This High pressure pump being a high inertia load requires very high torque at the time of starting. This high starting torque requirement results in increased acceleration time of the motor which subsequently increases the strain on the upstream electrical system from motor feeder to transformer. Such starting characteristic necessitates provision of special starting scheme for the high pressure pump motors. Sea water reverse osmosis (SWRO) plant of Nuclear Desalination Demonstration Project (NDDP) was commissioned in October 2002 at Kalpakkam, India. This paper presents the experiences of problems faced due to the typical starting characteristics of High Pressure pumps and provision of series reactor type motor starter for the same. (author)

LEP dismantling starts

CERN Multimedia

2000-01-01

Since the end of November, various teams have been getting stuck into dismantling the LEP accelerator and its four experiments. After making the installations safe, the dismantling and removal of 40,000 tonnes of equipment is underway. Down in the tunnel, it is a solemn moment. It is 10 o'clock on 13 December and Daniel Regin, one of those heading the dismantling work, moves in on a magnet, armed with a hydraulic machine. Surrounded by teams gathered there for a course in dismantling, he makes the first cut into LEP. The great deconstruction has begun. In little over than a year, the accelerator will have been cleared away to make room for its successor, the LHC. The start of the operation goes back to 27 November. Because before setting about the machine with hydraulic shears and monkey wrenches, LEP had first to be made safe - it was important to make sure the machine could be taken apart without risk. All the SPS beam injection systems to LEP were cut off. The fluids used for cooling the magnets and superc...

Start-to-end simulations of SASE FEL at the TESLA Test Facility

International Nuclear Information System (INIS)

Dohlus, M.; Floettmann, K.; Limberg, T.; Saldin, E.L; Schneidmiller, E.A.; Kozlov, O.S.; Yurkov, M.V.; Piot, Ph.

2004-01-01

VUV SASE FEL at the TESLA Test Facility (Phase 1) was successfully running and reached saturation in the wavelength range 80-120 nm. We present a posteriori start-to-end simulations of this machine. The codes Astra and elegant are used to track particle distribution from the cathode to the undulator entrance. An independent simulation of the beam dynamics in the bunch compressor is performed with the code CSRtrack. SASE FEL process is simulated with the code FAST. The simulation results are in good agreement with the measured properties of SASE FEL radiation. It is shown that the beam dynamics after the bunch compressor is mainly defined by space charge fields. FEL radiation is produced by the head of the electron bunch having a peak current of about 3 kA and a duration of 100 fs

Financial planning and control in very small start-up companies: antecedents and effects on company performance

NARCIS (Netherlands)

Mengel, S.; Wouters, M.

2015-01-01

This study motivates and tests hypotheses about the antecedents of the use of financial planning and control systems in very small and young start-up firms, and, in turn, the effect of this on firm performance. This setting is of particular interest since theory on financial planning and control in

Effects of Cavity on the Performance of Dual Throat Nozzle During the Thrust-Vectoring Starting Transient Process.

Science.gov (United States)

Gu, Rui; Xu, Jinglei

2014-01-01

The dual throat nozzle (DTN) technique is capable to achieve higher thrust-vectoring efficiencies than other fluidic techniques, without compromising thrust efficiency significantly during vectoring operation. The excellent performance of the DTN is mainly due to the concaved cavity. In this paper, two DTNs of different scales have been investigated by unsteady numerical simulations to compare the parameter variations and study the effects of cavity during the vector starting process. The results remind us that during the vector starting process, dynamic loads may be generated, which is a potentially challenging problem for the aircraft trim and control.

Head injury: audit of a clinical guideline to justify head CT

International Nuclear Information System (INIS)

Haydon, Nicholas B.

2013-01-01

Head injury causes significant morbidity and mortality, and there is contention about which patients to scan. The UK National Health Service Clinical Guideline (CG) 56 provides criteria for selecting patients with clinically important brain injury who may benefit from a head CT scan, while minimising the radiation and economic burden of scanning patients without significant injury. This study aims to audit the documentation of the use of these guidelines in a busy UK trauma hospital and discusses the comparison with an Australian (New South Wales (NSW) ) head injury guideline. A retrospective cohort study of 480 patients presenting with head injury to the emergency department over 2 months was performed. The patient notes were assessed for documentation of each aspect of the clinical guidelines. Criteria were established to assess the utilisation of the CG 56. A database of clinical data was amalgamated with the head CT scan results for each patient. For the UK CG 56, 73% of the criteria were documented, with the least documented being 'signs of basal skull fracture' and 'amnesia of events'. Thirty-two per cent of patients received head CT and of these, 24% (37 patients) were reported to have pathology. Twenty-four patients underwent head CT without clinical justification being documented, none of which had reported pathology on CT. The study shows that the head injury guidelines are not being fully utilised at a major UK trauma hospital, resulting in 5% of patients being exposed to ionising radiation without apparent documented clinical justification. The NSW guideline has distinct differences to the CG 56, with a more complex algorithm and an absence of specific time frames for head CT completion. The results suggest a need for further education and awareness of head injury clinical guidelines.

Cutting performances with new industrial continuous wave ND:YAG high power lasers

International Nuclear Information System (INIS)

Chagnot, C.; Dinechin, G. de; Canneau, G.

2010-01-01

Dismantling is a great challenge for nuclear companies which are facing with the cleaning of former nuclear sites. Among the available cutting processes is the multi-kilowatts laser whose power is transmitted through optical fibers. Unlike other cutting processes such as the plasma arc cutting process or the oxy-cutting process, the laser process can be easily implemented by robotic equipments. The mechanised robotic arm carries a laser cutting head to perform, with remote-controlled equipments, the cutting operation. The present study deals with the performances which can be reached with high power continuous wave ND:YAG lasers. The cutting tests were carried out up to 8 kW. The laser power was delivered through a specific power supply chain: a 0.4 mm fiber was transporting the power from the laser to a first interface (coupler) then a second 0.6 mm fiber was bringing the laser power to the cutting head. This solution allowed a power delivery chain whose length could be as high as 100 + 20/50 m. Another advantage of this kind of power supply is that the first fiber can be set in a non-contaminated environment whereas the second fiber lies in the contaminated area. The cutting head used for these tests was a specific tool developed for this laser dismantling work: it is a laser cutting head cooled by pressurized air. This tool was developed with the requirement to be able to sustain a laser power of 14 kW. The pressurized air used to cool the head is also used as cutting gas. The cutting capability was about 10 mm by kW. At the power of 8 kW, austenitic steel plates of thickness 100 mm were cut. These performances were reached with the cut started on the plate's edge. If the cut started in the middle of the plate, the cutting performances were not so high: 8 kW became the power to drill and to cut plates of thickness 40 mm.

A guided self-help intervention targeting psychological distress among head and neck cancer and lung cancer patients: motivation to start, experiences and perceived outcomes.

Science.gov (United States)

Krebber, Anne-Marie H; van Uden-Kraan, Cornelia F; Melissant, Heleen C; Cuijpers, Pim; van Straten, Annemieke; Becker-Commissaris, Annemarie; Leemans, C René; Verdonck-de Leeuw, Irma M

2017-01-01

Recent results of a randomized clinical trial showed that a guided self-help intervention (based on problem-solving therapy) targeting psychological distress among head and neck cancer and lung cancer patients is effective. This study qualitatively explored motivation to start, experiences with and perceived outcomes of this intervention. Data were collected from semi-structured interviews of 16 patients. All interviews were audio-recorded and transcribed verbatim. Data were analyzed individually by two coders and coded into key issues and themes. Patients participated in the intervention for intrinsic (e.g. to help oneself) and for extrinsic reasons (e.g. being asked by a care professional or to help improve health care). Participants indicated positive and negative experiences with the intervention. Several participants appreciated participating as being a pleasant way to work on oneself, while others described participating as too confrontational. Some expressed their disappointment as they felt the intervention had brought them nothing or indicated that they felt worse temporarily, but most participants perceived positive outcomes of the intervention (e.g. feeling less distressed and having learned what matters in life). Cancer patients have various reasons to start a guided self-help intervention. Participants appreciated the guided self-help as intervention to address psychological distress, but there were also concerns. Most participants reported the intervention to be beneficial. The results suggest the need to identify patients who might benefit most from guided self-help targeting psychological distress and that interventions should be further tailored to individual cancer patients' requirements.

Ulnar nerve entrapment complicating radial head excision

Directory of Open Access Journals (Sweden)

Kevin Parfait Bienvenu Bouhelo-Pam

Full Text Available Introduction: Several mechanisms are involved in ischemia or mechanical compression of ulnar nerve at the elbow. Presentation of case: We hereby present the case of a road accident victim, who received a radial head excision for an isolated fracture of the radial head and complicated by onset of cubital tunnel syndrome. This outcome could be the consequence of an iatrogenic valgus of the elbow due to excision of the radial head. Hitherto the surgical treatment of choice it is gradually been abandoned due to development of radial head implant arthroplasty. However, this management option is still being performed in some rural centers with low resources. Discussion: The radial head plays an important role in the stability of the elbow and his iatrogenic deformity can be complicated by cubital tunnel syndrome. Conclusion: An ulnar nerve release was performed with favorable outcome. Keywords: Cubital tunnel syndrome, Peripheral nerve palsy, Radial head excision, Elbow valgus

Driving While Interacting With Google Glass: Investigating the Combined Effect of Head-Up Display and Hands-Free Input on Driving Safety and Multitask Performance.

Science.gov (United States)

Tippey, Kathryn G; Sivaraj, Elayaraj; Ferris, Thomas K

2017-06-01

This study evaluated the individual and combined effects of voice (vs. manual) input and head-up (vs. head-down) display in a driving and device interaction task. Advances in wearable technology offer new possibilities for in-vehicle interaction but also present new challenges for managing driver attention and regulating device usage in vehicles. This research investigated how driving performance is affected by interface characteristics of devices used for concurrent secondary tasks. A positive impact on driving performance was expected when devices included voice-to-text functionality (reducing demand for visual and manual resources) and a head-up display (HUD) (supporting greater visibility of the driving environment). Driver behavior and performance was compared in a texting-while-driving task set during a driving simulation. The texting task was completed with and without voice-to-text using a smartphone and with voice-to-text using Google Glass's HUD. Driving task performance degraded with the addition of the secondary texting task. However, voice-to-text input supported relatively better performance in both driving and texting tasks compared to using manual entry. HUD functionality further improved driving performance compared to conditions using a smartphone and often was not significantly worse than performance without the texting task. This study suggests that despite the performance costs of texting-while-driving, voice input methods improve performance over manual entry, and head-up displays may further extend those performance benefits. This study can inform designers and potential users of wearable technologies as well as policymakers tasked with regulating the use of these technologies while driving.

Heading and head injuries in soccer.

Science.gov (United States)

Kirkendall, D T; Jordan, S E; Garrett, W E

2001-01-01

In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

The head-mounted microscope.

Science.gov (United States)

Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

2012-04-01

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Less efficient oculomotor performance is associated with increased incidence of head impacts in high school ice hockey.

Science.gov (United States)

Kiefer, Adam W; DiCesare, Christopher; Nalepka, Patrick; Foss, Kim Barber; Thomas, Staci; Myer, Gregory D

2018-01-01

To evaluate associations between pre-season oculomotor performance on visual tracking tasks and in-season head impact incidence during high school boys ice hockey. Prospective observational study design. Fifteen healthy high school aged male hockey athletes (M=16.50±1.17years) performed two 30s blocks each of a prosaccade and self-paced saccade task, and two trials each of a slow, medium, and fast smooth pursuit task (90°s -1 ; 180°s -1 ; 360°s -1 ) during the pre-season. Regular season in-game collision data were collected via helmet-mounted accelerometers. Simple linear regressions were used to examine relations between oculomotor performance measures and collision incidence at various impact thresholds. The variability of prosaccade latency was positively related to total collisions for the 20g force cutoff (p=0.046, adjusted R 2 =0.28). The average self-paced saccade velocity (p=0.020, adjusted R 2 =0.37) and variability of smooth pursuit gaze velocity (p=0.012, adjusted R 2 =0.47) were also positively associated with total collisions for the 50g force cutoff. These results provide preliminary evidence that less efficient oculomotor performance on three different oculomotor tasks is associated with increased incidence of head impacts during a competitive ice hockey season. The variability of prosaccade latency, the average self-paced saccade velocity and the variability of gaze velocity during predictable smooth pursuit all related to increased head impacts. Future work is needed to further understand player initiated collisions, but this is an important first step toward understanding strategies to reduce incidence of injury risk in ice hockey, and potentially contact sports more generally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

School start time effects on adolescent learning and academic performance, emotional health and behaviour.

Science.gov (United States)

Wahlstrom, Kyla L; Owens, Judith A

2017-11-01

The investigation of the relationship between the time of day that school begins and the effects it could have on students began in the mid-1990s. Since that time, many articles have been written either for the medical literature or the educational literature. This review is intended to bridge that gap by examining together the findings for both academic and health outcomes, exploring what we know and what is needed in further investigation. Teens who are sleep deficient (defined as obtaining less than 8 h per night) because of early starting time for their school are much more likely to engage in risky behaviours, such as drug, cigarette and alcohol use, have significant feelings of depression, get lower grades and are at greater risk for car crashes. Many studies of academic performance and later school start time indicate benefits, although further research is needed to understand the related mechanisms that contribute to improvements in achievement. Recent research in adolescent sleep and outcomes is being shaped by not only measuring sleep duration, but also examining the timing in which sleep occurs. Early school starting time for middle and high students has a clear, deleterious effect on their health and well being. Most recently, sleep deficit in teens is being viewed as a public health issue that needs a wider discussion about its impact and it necessitates improved public education about the sleep phase shift that occurs during adolescence.

First Class Call Stacks: Exploring Head Reduction

Directory of Open Access Journals (Sweden)

Philip Johnson-Freyd

2016-06-01

Full Text Available Weak-head normalization is inconsistent with functional extensionality in the call-by-name λ-calculus. We explore this problem from a new angle via the conflict between extensionality and effects. Leveraging ideas from work on the λ-calculus with control, we derive and justify alternative operational semantics and a sequence of abstract machines for performing head reduction. Head reduction avoids the problems with weak-head reduction and extensionality, while our operational semantics and associated abstract machines show us how to retain weak-head reduction's ease of implementation.

Supplemented Triage and Rapid Treatment (START) improves performance measures in the emergency department.

Science.gov (United States)

White, Benjamin A; Brown, David F M; Sinclair, Julia; Chang, Yuchiao; Carignan, Sarah; McIntyre, Joyce; Biddinger, Paul D

2012-03-01

Emergency Department (ED) crowding is well recognized, and multiple studies have demonstrated its negative effect on patient care. This study aimed to assess the effect of an intervention, Supplemented Triage and Rapid Treatment (START), on standard ED performance measures. The START program complemented standard ED triage with a team of clinicians who initiated the diagnostic work-up and selectively accelerated disposition in a subset of patients. This retrospective before-after study compared performance measures over two 3-month periods (September-November 2007 and 2008) in an urban, academic tertiary care ED. Data from an electronic patient tracking system were queried over 12,936 patients pre-intervention, and 14,220 patients post-intervention. Primary outcomes included: 1) overall length of stay (LOS), 2) LOS for discharged and admitted patients, and 3) the percentage of patients who left without complete assessment (LWCA). In the post-intervention period, patient volume increased 9% and boarder hours decreased by 1.3%. Median overall ED LOS decreased by 29 min (8%, 361 min pre-intervention, 332 min post-intervention; p < 0.001). Median LOS for discharged patients decreased by 23 min (7%, 318 min pre-intervention, 295 min post-intervention; p < 0.001), and by 31 min (7%, 431 min pre-intervention, 400 min post-intervention) for admitted patients. LWCA was decreased by 1.7% (4.1% pre-intervention, 2.4% post-intervention; p < 0.001). In this study, a comprehensive screening and clinical care program was associated with a significant decrease in overall ED LOS, LOS for discharged and admitted patients, and rate of LWCA, despite an increase in ED patient volume. Copyright © 2012 Elsevier Inc. All rights reserved.

Prediction value of the Canadian CT head rule and the New Orleans criteria for positive head CT scan and acute neurosurgical procedures in minor head trauma: a multicenter external validation study.

Science.gov (United States)

Bouida, Wahid; Marghli, Soudani; Souissi, Sami; Ksibi, Hichem; Methammem, Mehdi; Haguiga, Habib; Khedher, Sonia; Boubaker, Hamdi; Beltaief, Kaouthar; Grissa, Mohamed Habib; Trimech, Mohamed Naceur; Kerkeni, Wiem; Chebili, Nawfel; Halila, Imen; Rejeb, Imen; Boukef, Riadh; Rekik, Noureddine; Bouhaja, Bechir; Letaief, Mondher; Nouira, Semir

2013-05-01

The New Orleans Criteria and the Canadian CT Head Rule have been developed to decrease the number of normal computed tomography (CT) results in mild head injury. We compare the performance of both decision rules for identifying patients with intracranial traumatic lesions and those who require an urgent neurosurgical intervention after mild head injury. This was an observational cohort study performed between 2008 and 2011 on patients with mild head injury who were aged 10 years or older. We collected prospectively clinical head CT scan findings and outcome. Primary outcome was need for neurosurgical intervention, defined as either death or craniotomy, or the need of intubation within 15 days of the traumatic event. Secondary outcome was the presence of traumatic lesions on head CT scan. New Orleans Criteria and Canadian CT Head Rule decision rules were compared by using sensitivity specifications and positive and negative predictive value. We enrolled 1,582 patients. Neurosurgical intervention was performed in 34 patients (2.1%) and positive CT findings were demonstrated in 218 patients (13.8%). Sensitivity and specificity for need for neurosurgical intervention were 100% (95% confidence interval [CI] 90% to 100%) and 60% (95% CI 44% to 76%) for the Canadian CT Head Rule and 82% (95% CI 69% to 95%) and 26% (95% CI 24% to 28%) for the New Orleans Criteria. Negative predictive values for the above-mentioned clinical decision rules were 100% and 99% and positive values were 5% and 2%, respectively, for the Canadian CT Head Rule and New Orleans Criteria. Sensitivity and specificity for clinical significant head CT findings were 95% (95% CI 92% to 98%) and 65% (95% CI 62% to 68%) for the Canadian CT Head Rule and 86% (95% CI 81% to 91%) and 28% (95% CI 26% to 30%) for the New Orleans Criteria. A similar trend of results was found in the subgroup of patients with a Glasgow Coma Scale score of 15. For patients with mild head injury, the Canadian CT Head Rule had higher

SU-E-T-605: Performance Evaluation of MLC Leaf-Sequencing Algorithms in Head-And-Neck IMRT

Energy Technology Data Exchange (ETDEWEB)

Jing, J; Lin, H [Hefei University of Technology, Hefei, Anhui (China); Chow, J [Princess Margaret Hospital, Toronto, ON (Canada)

2015-06-15

Purpose: To investigate the efficiency of three multileaf collimator (MLC) leaf-sequencing algorithms proposed by Galvin et al, Chen et al and Siochi et al using external beam treatment plans for head-and-neck intensity modulated radiation therapy (IMRT). Methods: IMRT plans for head-and-neck were created using the CORVUS treatment planning system. The plans were optimized and the fluence maps for all photon beams determined. Three different MLC leaf-sequencing algorithms based on Galvin et al, Chen et al and Siochi et al were used to calculate the final photon segmental fields and their monitor units in delivery. For comparison purpose, the maximum intensity of fluence map was kept constant in different plans. The number of beam segments and total number of monitor units were calculated for the three algorithms. Results: From results of number of beam segments and total number of monitor units, we found that algorithm of Galvin et al had the largest number of monitor unit which was about 70% larger than the other two algorithms. Moreover, both algorithms of Galvin et al and Siochi et al have relatively lower number of beam segment compared to Chen et al. Although values of number of beam segment and total number of monitor unit calculated by different algorithms varied with the head-and-neck plans, it can be seen that algorithms of Galvin et al and Siochi et al performed well with a lower number of beam segment, though algorithm of Galvin et al had a larger total number of monitor units than Siochi et al. Conclusion: Although performance of the leaf-sequencing algorithm varied with different IMRT plans having different fluence maps, an evaluation is possible based on the calculated number of beam segment and monitor unit. In this study, algorithm by Siochi et al was found to be more efficient in the head-and-neck IMRT. The Project Sponsored by the Fundamental Research Funds for the Central Universities (J2014HGXJ0094) and the Scientific Research Foundation for the

SU-E-T-605: Performance Evaluation of MLC Leaf-Sequencing Algorithms in Head-And-Neck IMRT

International Nuclear Information System (INIS)

Jing, J; Lin, H; Chow, J

2015-01-01

Purpose: To investigate the efficiency of three multileaf collimator (MLC) leaf-sequencing algorithms proposed by Galvin et al, Chen et al and Siochi et al using external beam treatment plans for head-and-neck intensity modulated radiation therapy (IMRT). Methods: IMRT plans for head-and-neck were created using the CORVUS treatment planning system. The plans were optimized and the fluence maps for all photon beams determined. Three different MLC leaf-sequencing algorithms based on Galvin et al, Chen et al and Siochi et al were used to calculate the final photon segmental fields and their monitor units in delivery. For comparison purpose, the maximum intensity of fluence map was kept constant in different plans. The number of beam segments and total number of monitor units were calculated for the three algorithms. Results: From results of number of beam segments and total number of monitor units, we found that algorithm of Galvin et al had the largest number of monitor unit which was about 70% larger than the other two algorithms. Moreover, both algorithms of Galvin et al and Siochi et al have relatively lower number of beam segment compared to Chen et al. Although values of number of beam segment and total number of monitor unit calculated by different algorithms varied with the head-and-neck plans, it can be seen that algorithms of Galvin et al and Siochi et al performed well with a lower number of beam segment, though algorithm of Galvin et al had a larger total number of monitor units than Siochi et al. Conclusion: Although performance of the leaf-sequencing algorithm varied with different IMRT plans having different fluence maps, an evaluation is possible based on the calculated number of beam segment and monitor unit. In this study, algorithm by Siochi et al was found to be more efficient in the head-and-neck IMRT. The Project Sponsored by the Fundamental Research Funds for the Central Universities (J2014HGXJ0094) and the Scientific Research Foundation for the

Nontraumatic head and neck emergencies: a clinical approach. Part 1: cervicofacial swelling, dysphagia, and dyspnea.

Science.gov (United States)

Brea Álvarez, B; Tuñón Gómez, M; Esteban García, L; García Hidalgo, C Y; Ruiz Peralbo, R M

2016-01-01

Nontraumatic emergencies of the head and neck represent a challenge in the field of neuroradiology for two reasons: first, they affect an area where the thorax joins the cranial cavity and can thus compromise both structures; second, they are uncommon, so they are not well known. Various publications focus on nontraumatic emergencies of the head and neck from the viewpoints of anatomic location or of particular diseases. However, these are not the most helpful viewpoints for dealing with patients in the emergency department, who present with particular signs and symptoms. We propose an analysis starting from the four most common clinical presentations of patients who come to the emergency department for nontraumatic head and neck emergencies: cervical swelling, dysphagia, dyspnea, and loss of vision. Starting from these entities, we develop an approach to the radiologic management and diagnosis of these patients. Copyright © 2016 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

The clinical application of head-ring type posture pad used for prone position in performing the placement of central venous catheter in patients with tumors

International Nuclear Information System (INIS)

Chen Meiqian; Wang Chunmei; Chen Feiyin; Zhang Lubing

2011-01-01

Objective: to observe the effectiveness of head-ring type posture pad used for prone position in performing the procedure of peripheral insertion of central catheter (PICC) via the dorsal forearm vein in patients with neoplasm. Methods: A total of 80 consecutive tumor patients were randomly divided into two groups. PICC was carried out in all patients in prone position. In control group (n=38) PICC was performed with patient's head inclining to one side, while in study group (n=42) PICC was performed with the help of head-ring type pad to keep the patient in comfortable posture. The comfortableness, breathing rhythm, transcutaneous oxygen saturation and the change of heart rate during the procedure were observed. The results were analyzed and compared between the two groups. Results: The results is study group were much better than those in control group. Statistically significant difference in the comfortableness, breathing rhythm, transcutaneous oxygen saturation and heart rate existed between the two groups. Conclusion: The head-ring type posture pad used for prone position can make the patients more comfortable in performing peripheral insertion of central venous catheter via the dorsal forearm vein. (authors)

Performance of computed tomography of the head to evaluate for skull fractures in infants with suspected non-accidental trauma

Energy Technology Data Exchange (ETDEWEB)

Culotta, Paige A.; Tran, Quynh-Anh; Donaruma-Kwoh, Marcella [Texas Children' s Hospital, Section of Public Health Pediatrics, Baylor College of Medicine, Houston, TX (United States); Crowe, James E.; Jones, Jeremy Y.; Mehollin-Ray, Amy R.; Tran, H.B.; Dodge, Cristina T. [Texas Children' s Hospital, The Edward B. Singleton, MD, Department of Pediatric Radiology, Baylor College of Medicine, Houston, TX (United States); Camp, Elizabeth A. [Texas Children' s Hospital, Emergency Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, TX (United States); Cruz, Andrea T. [Texas Children' s Hospital, Emergency Medicine, Department of Pediatrics, Baylor College of Medicine, Houston, TX (United States); Texas Children' s Hospital, Infectious Diseases, Department of Pediatrics, Baylor College of Medicine, Houston, TX (United States)

2017-01-15

Young children with suspected abusive head trauma often receive skull radiographs to evaluate for fractures as well as computed tomography (CT) of the head to assess for intracranial injury. Using a CT as the primary modality to evaluate both fracture and intracranial injury could reduce exposure to radiation without sacrificing performance. To evaluate the sensitivity of CT head with (3-D) reconstruction compared to skull radiographs to identify skull fractures in children with suspected abusive head trauma. This was a retrospective (2013-2014) cross-sectional study of infants evaluated for abusive head trauma via both skull radiographs and CT with 3-D reconstruction. The reference standard was skull radiography. All studies were read by pediatric radiologists and neuroradiologists, with ten percent read by a second radiologist to evaluate for interobserver reliability. One hundred seventy-seven children (47% female; mean/median age: 5 months) were included. Sixty-two (35%) had skull fractures by radiography. CT with 3-D reconstruction was 97% sensitive (95% confidence interval [CI]: 89-100%) and 94% specific (CI: 87-97%) for skull fracture. There was no significant difference between plain radiographs and 3-D CT scan results (P-value = 0.18). Kappa was 1 (P-value <0.001) between radiologist readings of CTs and 0.77 (P = 0.001) for skull radiographs. CT with 3-D reconstruction is equivalent to skull radiographs in identifying skull fractures. When a head CT is indicated, skull radiographs add little diagnostic value. (orig.)

Numerical and experimental study of actuator performance on piezoelectric microelectromechanical inkjet print head.

Science.gov (United States)

Van So, Pham; Jun, Hyun Woo; Lee, Jaichan

2013-12-01

We have investigated the actuator performance of a piezoelectrically actuated inkjet print head via the numerical and experimental analysis. The actuator consisting of multi-layer membranes, such as piezoelectric, elastic and other buffer layers, and ink chamber was fabricated by MEMS processing. The maximum displacement of the actuator membrane obtained in the experiment is explained by numerical analysis. A simulation of the actuator performance with fluidic damping shows that the resonant frequency of the membrane in liquid is reduced from its resonant frequency in air by a factor of three, which was also verified in the experiment. These simulation and experimental studies demonstrate how much "dynamic force," in terms of a membrane's maximum displacement, maximum force and driving frequency, can be produced by an actuator membrane interacting with fluid.

Allocation of Attention with Head-Up Displays

National Research Council Canada - National Science Library

Wickens, C

1998-01-01

Two experiments examined the effects of display location (head up vs. head down) and image intensity/clutter on flight path performance and mid-air target detection in a general aviation cruise flight environment...

Significance of head CT in neuro-ophthalmology

International Nuclear Information System (INIS)

Nishimoto, Yuichiro; Masuyama, Yoshimasa; Nakamura, Yasuko; Fujimoto, Toshiro.

1979-01-01

It is important to perform CT purposefully in patients with some neuro-ophthalmological disorders. Using Hitachi CT-H250 with the finer matrix of 256 x 256 and a section thickness of 5 mm and 10 mm, we performed head CT in 98 patients with various kinds of neuro-ophthalmological disorders in these 30 months. Neuro-ophthalmological findings in these patients were visual disturbance, visual field defects (hemianopsia, quandrantanopsia, enlargement of the blind spot, central scotoma), papilledema, optic nerve atrophy, difficulties in ocular movements, and others. In 44 (44.9%) of these 98 patients, abnormal findings were displayed in the head CT, characterizing intracranial tumors, intracranial infarction, aneurysms in intracranial vessels, arterio-venous malformation, enlargement of the ventricle or the cistern. In some cases the head CT was the decisive procedure in ensuring a correct diagnosis. We presented findings in the head CT in several interesting cases. We recognized the necessity of the head CT in patients with neuro-ophthalmological disorders. (author)

Heading perception in patients with advanced retinitis pigmentosa

Science.gov (United States)

Li, Li; Peli, Eli; Warren, William H.

2002-01-01

PURPOSE: We investigated whether retinis pigmentosa (RP) patients with residual visual field of < 100 degrees could perceive heading from optic flow. METHODS: Four RP patients and four age-matched normally sighted control subjects viewed displays simulating an observer walking over a ground. In experiment 1, subjects viewed either the entire display with free fixation (full-field condition) or through an aperture with a fixation point at the center (aperture condition). In experiment 2, patients viewed displays of different durations. RESULTS: RP patients' performance was comparable to that of the age-matched control subjects: heading judgment was better in the full-field condition than in the aperture condition. Increasing display duration from 0.5 s to 1 s improved patients' heading performance, but giving them more time (3 s) to gather more visual information did not consistently further improve their performance. CONCLUSIONS: RP patients use active scanning eye movements to compensate for their visual field loss in heading perception; they might be able to gather sufficient optic flow information for heading perception in about 1 s.

STARTING BLOCK PERFORMANCE IN SPRINTERS: A STATISTICAL METHOD FOR IDENTIFYING DISCRIMINATIVE PARAMETERS OF THE PERFORMANCE AND AN ANALYSIS OF THE EFFECT OF PROVIDING FEEDBACK OVER A 6-WEEK PERIOD

Directory of Open Access Journals (Sweden)

Sylvie Fortier

2005-06-01

Full Text Available The purpose of this study was twofold: (a to examine if kinetic and kinematic parameters of the sprint start could differentiate elite from sub-elite sprinters and, (b to investigate whether providing feedback (FB about selected parameters could improve starting block performance of intermediate sprinters over a 6-week training period. Twelve male sprinters, assigned to an elite or a sub-elite group, participated in Experiment 1. Eight intermediate sprinters participated in Experiment 2. All athletes were required to perform three sprint starts at maximum intensity followed by a 10-m run. To detect differences between elite and sub-elite groups, comparisons were made using t-tests for independent samples. Parameters reaching a significant group difference were retained for the linear discriminant analysis (LDA. The LDA yielded four discriminative kinetic parameters. Feedback about these selected parameters was given to sprinters in Experiment 2. For this experiment, data acquisition was divided into three periods. The first six sessions were without specific FB, whereas the following six sessions were enriched by kinetic FB. Finally, athletes underwent a retention session (without FB 4 weeks after the twelfth session. Even though differences were found in the time to front peak force, the time to rear peak force, and the front peak force in the retention session, the results of the present study showed that providing FB about selected kinetic parameters differentiating elite from sub-elite sprinters did not improve the starting block performance of intermediate sprinters

EmptyHeaded: A Relational Engine for Graph Processing.

Science.gov (United States)

Aberger, Christopher R; Tu, Susan; Olukotun, Kunle; Ré, Christopher

2016-01-01

There are two types of high-performance graph processing engines: low- and high-level engines. Low-level engines (Galois, PowerGraph, Snap) provide optimized data structures and computation models but require users to write low-level imperative code, hence ensuring that efficiency is the burden of the user. In high-level engines, users write in query languages like datalog (SociaLite) or SQL (Grail). High-level engines are easier to use but are orders of magnitude slower than the low-level graph engines. We present EmptyHeaded, a high-level engine that supports a rich datalog-like query language and achieves performance comparable to that of low-level engines. At the core of EmptyHeaded's design is a new class of join algorithms that satisfy strong theoretical guarantees but have thus far not achieved performance comparable to that of specialized graph processing engines. To achieve high performance, EmptyHeaded introduces a new join engine architecture, including a novel query optimizer and data layouts that leverage single-instruction multiple data (SIMD) parallelism. With this architecture, EmptyHeaded outperforms high-level approaches by up to three orders of magnitude on graph pattern queries, PageRank, and Single-Source Shortest Paths (SSSP) and is an order of magnitude faster than many low-level baselines. We validate that EmptyHeaded competes with the best-of-breed low-level engine (Galois), achieving comparable performance on PageRank and at most 3× worse performance on SSSP.

Comparison of recessed gate-head structures on normally-off AlGaN/GaN high-electron-mobility transistor performance.

Science.gov (United States)

Khan, Mansoor Ali; Heo, Jun-Woo; Kim, Hyun-Seok; Park, Hyun-Chang

2014-11-01

In this work, different gate-head structures have been compared in the context of AlGaN/GaN-based high-electron-mobility transistors (HEMTs). Field-plate (FP) technology self-aligned to the gate electrode leads to various gate-head structures, most likely gamma (γF)-gate, camel (see symbol)-gate, and mushroom-shaped (T)-gate. In-depth comparison of recessed gate-head structures demonstrated that key performance metrics such as transconductance, output current, and breakdown voltage are better with the T-gate head structure. The recessed T-gate with its one arm toward the source side not only reduces the source-access resistance (R(g) +R(gs)), but also minimizes the source-side dispersion and current leakage, resulting in high transconductance (G(m)) and output current (I(DS)). At the same time, the other arm toward the drain-side reduces the drain-side dispersion and tends to distribute electric field peaks uniformly, resulting in high breakdown voltage (V(BR)). DC and RF analysis showed that the recessed T-gate FP-HEMT is a suitable candidate not only for high-frequency operation, but also for high-power applications.

Muscle Fatigue in the Three Heads of the Triceps Brachii During a Controlled Forceful Hand Grip Task with Full Elbow Extension Using Surface Electromyography.

Science.gov (United States)

Ali, Asraf; Sundaraj, Kenneth; Badlishah Ahmad, R; Ahamed, Nizam Uddin; Islam, Anamul; Sundaraj, Sebastian

2015-06-27

The objective of the present study was to investigate the time to fatigue and compare the fatiguing condition among the three heads of the triceps brachii muscle using surface electromyography during an isometric contraction of a controlled forceful hand grip task with full elbow extension. Eighteen healthy subjects concurrently performed a single 90 s isometric contraction of a controlled forceful hand grip task and full elbow extension. Surface electromyographic signals from the lateral, long and medial heads of the triceps brachii muscle were recorded during the task for each subject. The changes in muscle activity among the three heads of triceps brachii were measured by the root mean square values for every 5 s period throughout the total contraction period. The root mean square values were then analysed to determine the fatiguing condition for the heads of triceps brachii muscle. Muscle fatigue in the long, lateral, and medial heads of the triceps brachii started at 40 s, 50 s, and 65 s during the prolonged contraction, respectively. The highest fatiguing rate was observed in the long head (slope = -2.863), followed by the medial head (slope = -2.412) and the lateral head (slope = -1.877) of the triceps brachii muscle. The results of the present study concurs with previous findings that the three heads of the triceps brachii muscle do not work as a single unit, and the fiber type/composition is different among the three heads.

We Look More, Listen More, Notice More: Impact of Sustained Professional Development on Head Start Teachers' Inquiry-Based and Culturally-Relevant Science Teaching Practices

Science.gov (United States)

Roehrig, Gillian H.; Dubosarsky, Mia; Mason, Annie; Carlson, Stephan; Murphy, Barbara

2011-10-01

Despite many scholars' recommendations, science is often avoided during early childhood education. Among the reasons provided by early childhood teachers for the exclusion of science from their daily routines included science anxiety, low self-efficacy with respect to teaching science, lack of experience participating in science activities as students, or the notion that literacy and language are more important during the early years. In minority populations the problem is even greater due to identification of science with the `culture of. This article presents results from Ah Neen Dush, a sustained and transformative professional development program for Head Start teachers on an American Indian Reservation. The goal of the program is to support early childhood teachers in developing inquiry-based and culturally-relevant teaching practices. Through analysis of teachers' classroom practices, surveys and interviews, we explore changes in teachers' attitudes toward science and inquiry-based practices. Classroom observations were conducted using CLASS (Classroom assessment Scoring System), a tool used to evaluate the quality of classroom interactions. After 1 year of professional development teachers' attitudes were found to improve and after 2 years teachers classroom practices were more inquiry-based with statistically significant increases in CLASS observation scores.

Silva as the Head

DEFF Research Database (Denmark)

Svabo, Connie

2015-01-01

The head of the performance design programme is substituted by a sister's academy delegate. this performance situation formed part of a week of semesterstart where the students and professors visited Sister's Academy, Malmø. I participated in the Sister's Academy as visiting researcher and here i...

[Duodenum-preserving total pancreatic head resection and pancreatic head resection with segmental duodenostomy].

Science.gov (United States)

Takada, Tadahiro; Yasuda, Hideki; Nagashima, Ikuo; Amano, Hodaka; Yoshiada, Masahiro; Toyota, Naoyuki

2003-06-01

A duodenum-preserving pancreatic head resection (DPPHR) was first reported by Beger et al. in 1980. However, its application has been limited to chronic pancreatitis because of it is a subtotal pancreatic head resection. In 1990, we reported duodenum-preserving total pancreatic head resection (DPTPHR) in 26 cases. This opened the way for total pancreatic head resection, expanding the application of this approach to tumorigenic morbidities such as intraductal papillary mucinous tumor (IMPT), other benign tumors, and small pancreatic cancers. On the other hand, Nakao et al. reported pancreatic head resection with segmental duodenectomy (PHRSD) as an alternative pylorus-preserving pancreatoduodenectomy technique in 24 cases. Hirata et al. also reported this technique as a new pylorus-preserving pancreatoduodenostomy with increased vessel preservation. When performing DPTPHR, the surgeon should ensure adequate duodenal blood supply. Avoidance of duodenal ischemia is very important in this operation, and thus it is necessary to maintain blood flow in the posterior pancreatoduodenal artery and to preserve the mesoduodenal vessels. Postoperative pancreatic functional tests reveal that DPTPHR is superior to PPPD, including PHSRD, because the entire duodenum and duodenal integrity is very important for postoperative pancreatic function.

Head and Helmet Biodynamics and Tracking Performance in Vibration Environments

National Research Council Canada - National Science Library

Smith, Suzanne D; Smith, Jeanne A

2006-01-01

...) and Up (40" elevation, 0" azimuth)], and three helmet CCs were tested. The overall head, helmet, and helmet slippage displacement rotations, and rms tracking error and percent time-on-target were evaluated...

Head injury predictors in sports trauma--a state-of-the-art review.

Science.gov (United States)

Fernandes, Fábio A O; de Sousa, Ricardo J Alves

2015-08-01

Head injuries occur in a great variety of sports. Many of these have been associated with neurological injuries, affecting the central nervous system. Some examples are motorsports, cycling, skiing, horse riding, mountaineering and most contact sports such as football, ice and field hockey, soccer, lacrosse, etc. The outcome of head impacts in these sports can be very severe. The worst-case scenarios of permanent disability or even death are possibilities. Over recent decades, many In recent decades, a great number of head injury criteria and respective thresholds have been proposed. However, the available information is much dispersed and a consensus has still not been achieved regarding the best injury criteria or even their thresholds. This review paper gives a thorough overview of the work carried out by the scientific community in the field of impact biomechanics about head injuries sustained during sports activity. The main goal is to review the head injury criteria, as well as their thresholds. Several are reviewed, from the predictors based on kinematics to the ones based on human tissue thresholds. In this work, we start to briefly introduce the head injuries and their mechanisms commonly seen as a result of head trauma in sports. Then, we present and summarize the head injury criteria and their respective thresholds. © IMechE 2015.

Merkel cell carcinoma of the head and neck: poorer prognosis than non-head and neck sites.

Science.gov (United States)

Morand, G B; Madana, J; Da Silva, S D; Hier, M P; Mlynarek, A M; Black, M J

2016-04-01

Merkel cell carcinoma is a rare, aggressive neurocutaneous malignancy. This study investigated whether patients with Merkel cell carcinoma in the head and neck had poorer outcomes than patients with Merkel cell carcinoma located elsewhere. A retrospective study was performed of patients with Merkel cell carcinoma treated at the Jewish General Hospital in Montréal, Canada, from 1993 to 2013. Associations between clinicopathological characteristics and disease-free and disease-specific survival rates were examined according to the Kaplan-Meier method. Twenty-seven patients were identified. Although basic clinicopathological characteristics and treatments were similar between head and neck and non-head and neck Merkel cell carcinoma groups, disease-free and disease-specific survival rates were significantly lower in the head and neck Merkel cell carcinoma group (log-rank test; p = 0.043 and p = 0.001, respectively). Mortality was mainly due to distant metastasis. Patients with head and neck Merkel cell carcinoma had poorer survival rates than patients with non-head and neck Merkel cell carcinoma in our study. The tendency to obtain close margins, a less predictable metastatic pattern, and/or intrinsic tumour factors related to the head and neck may explain this discrepancy.

Hitting the nail on the head: Force vectors in verb semantics

NARCIS (Netherlands)

Goldschmidt, A.; Zwarts, J.

2016-01-01

Hitting the nail on the head: Forces in verb meanings Anja Goldschmidt (UU) & Joost Zwarts (UU) There is a growing recognition of the role of forces in verb meanings, starting with the seminal work of Leonard Talmy (Talmy 1985). In one line of research these forces are analyzed in terms of vectors,

Optimised intake stroke analysis for flat and dome head pistons ...

African Journals Online (AJOL)

Optimised intake stroke analysis for flat and dome head pistons. ... in understanding the performance characteristics optioned between flat head and dome head pistons in engine design. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

International Space Station Nickel-Hydrogen Battery Start-Up and Initial Performance

Science.gov (United States)

Cohen, Fred; Dalton, Penni J.

2001-01-01

International Space Station (ISS) Electric Power System (EPS) utilizes Nickel-Hydrogen (Ni-H2) batteries as part of its power system to store electrical energy. The batteries are charged during insolation and discharged during eclipse. The batteries are designed to operate at a 35% depth of discharge (DOD) maximum during normal operation. Thirty eight individual pressure vessel (IPV) Ni-H2 battery cells are series-connected and packaged in an Orbital Replacement Unit (ORU). Two ORUs are series-connected utilizing a total of 76 cells, to form one battery. The ISS is the first application for low earth orbit (LEO) cycling of this quantity of series-connected cells. The P6 Integrated Equipment Assembly (IEA) containing the initial ISS high-power components was successfully launched on November 30, 2000. The IEA contains 12 Battery Subassembly ORUs (6 batteries) that provide station power during eclipse periods. This paper will describe the battery hardware configuration, operation, and role in providing power to the main power system of the ISS. We will also discuss initial battery start-up and performance data.

Guidelines for starting today's private practice

Directory of Open Access Journals (Sweden)

Schmitz ED

2012-11-01

Full Text Available No abstract available. Article truncated at 150 words. Starting a new practice may seem like a daunting task. The purpose of this article is to demystify the process of creating a new practice from the beginning. The cardinal rule is to keep costs low and not to outsource work that can easily be performed by any competent physician and staff. You do not need a manager, lawyer, business partner, coder or biller individually; you may be able to perform many of these services yourself. What you do need is a commitment to making your practice a success. Do not spend too much on your office space, furnishings or equipment. Start with the bare essentials. Immediately start applying to all insurance companies especially Medicare. Request an employer identification number. Set up a basic business banking account and submit the account number to the insurance companies you plan to work with. You can purchase an entire electronic healthcare record (EHR …

Heads Up

Science.gov (United States)

... Connect with Us HEADS UP Apps Reshaping the Culture Around Concussion in Sports Get HEADS UP on Your Web Site Concussion ... HEADS UP on your web site! Create a culture of safety for young athletes Officials, learn how you can ... UP to Providers HEADS UP to Youth Sports HEADS UP to School Sports HEADS UP to ...

Measurement of flow inside a vacuum cleaner head

Science.gov (United States)

Iguchi, Ryotaro; Ban, Hisataka; Sakakibara, Jun

2017-11-01

Vacuum cleaner head with rotating brushes is widely used as a home appliance. Although it efficiently collects dusts from the floor, flow field of the air and motion of the dust inside the head have not been fully investigated. In this study, we performed 3D-PIV (particle tracking velocimetry) measurement of velocity field inside the head. Water was used as working fluid, which allows a use of fluorescent particle to reduce unwanted reflection from the brushes and inner surface of the head. Mean velocity field and turbulence statistics in the head with and without the brush will be presented.

Fundamental examinations for the mechanisation of the support work in headings by blasting and by using selective cut heading machines

Energy Technology Data Exchange (ETDEWEB)

Stoecker, H.M.; Luerig, H.J.

1982-01-01

Starting from the results of a stock-taking of the support methods used up to now and from exact analyses of the situation in the heading field, a concept will be elaborated with the aim, in addition to the reduction of the well-known high physical strain by the setting of the support, of rationalization of this partial procedure in case of conventional heading. The principal item is a floor-connected transportation and erection-vehicle with electro-hydraulic drive and an adjustable erection deck, which permits a fully mechanised setting of the support inclusive the side sections. By a transversible novel drilling equipment hung up at the roof of a drift a parallelization of different procedures and therewith a rationalization effect can be reached at the same time. The concept of this realizability will be demonstrated at a volume - right and power - right heading model on a scale 1:5. The developed equipment consist of operationally approved single aggregates and for the test they can also be used separately. Therewith a gradual introduction of the system is possible. At the beginning a provisional safety equipment for the direct at the face area will be introduced for the selective cut heading machine driving. According to the actual stage of the first considerations the main disadvantage of the safety equipment is the insufficient stock safety and its outrigger at the support already set.

Early components of the human vestibulo-ocular response to head rotation: latency and gain

NARCIS (Netherlands)

H. Collewijn (Han); J.B.J. Smeets (Jeroen)

2000-01-01

textabstractTo characterize vestibulo-ocular reflex (VOR) properties in the time window in which contributions by other systems are minimal, eye movements during the first 50-100 ms after the start of transient angular head accelerations ( approximately 1000 degrees

How network-based incubation helps start-up performance : a systematic review against the background of management theories

OpenAIRE

Eveleens, Chris P.; van Rijnsoever, Frank J.; Niesten, Eva M M I

2017-01-01

The literature on how network-based incubation influences the performance of technology-based start-ups has recently grown considerably and provided valuable insights. However, at the same time this literature has become quite fragmented, inconsistently conceptualised, and theoretically underdeveloped. Therefore, this article uses three management theories to structure the literature, improve the theoretical underpinning and develop an agenda for further research. The management theories are ...

Method for controlling start-up and steady state performance of a closed split flow recompression brayton cycle

Science.gov (United States)

Pasch, James Jay

2017-02-07

A method of resolving a balanced condition that generates control parameters for start-up and steady state operating points and various component and cycle performances for a closed split flow recompression cycle system. The method provides for improved control of a Brayton cycle thermal to electrical power conversion system. The method may also be used for system design, operational simulation and/or parameter prediction.

Start Later, Sleep Later: School Start Times and Adolescent Sleep in Homeschool vs. Public/Private School Students

Science.gov (United States)

Meltzer, Lisa J.; Shaheed, Keisha; Ambler, Devon

2014-01-01

Homeschool students provide a naturalistic comparison group for later/flexible school start times. This study compared sleep patterns and sleep hygiene for homeschool students and public/private school students (grades 6-12). Public/private school students (n=245) and homeschool students (n=162) completed a survey about sleep patterns and sleep hygiene. Significant school group differences were found for weekday bedtime, wake time, and total sleep time, with homeschool students waking later and obtaining more sleep. Homeschool students had later school start times, waking at the same time that public/private school students were starting school. Public/private school students had poorer sleep hygiene practices, reporting more homework and use of technology in the hour before bed. Regardless of school type, technology in the bedroom was associated with shorter sleep duration. Later school start times may be a potential countermeasure for insufficient sleep in adolescents. Future studies should further examine the relationship between school start times and daytime outcomes, including academic performance, mood, and health. PMID:25315902

A Robotic Fish to Emulate the Fast-Start

Science.gov (United States)

Currier, Todd; Ma, Ganzhong; Modarres-Sadeghi, Yahya

2017-11-01

An experimental study is conducted on a robotic fish designed to emulate the fast-start response. The fish body is constructed of 3D printed ribs and a light spring steel spine. The body is actuated using a series of pressured pistons. A total of four pistons are supplied with pressure through lightweight high pressure service lines. The source of pressure is carbon dioxide with a 700 psi peak operating pressure resulting in a body response that can cycle a c-start maneuver in milliseconds. The motion of the fish is precisely controlled through the use of solenoids with a control signal produced by a programmable microprocessor. The fish is constrained in all translational degrees of freedom but allowed to rotate about a vertical axis. The influence of the point of rotation is studied with different mounting points along the length of the head of the fish. The forces are measured in two perpendicular in-plane directions. A high speed camera is used to capture the response of the fish and the corresponding flow around it. Comparison is made with the kinematics observed in live fish.

Relationship Between Final Performance and Block Times with the Traditional and the New Starting Platforms with A Back Plate in International Swimming Championship 50-M and 100-M Freestyle Events

Science.gov (United States)

Garcia-Hermoso, Antonio; Escalante, Yolanda; Arellano, Raul; Navarro, Fernando; Domínguez, Ana M.; Saavedra, Jose M.

2013-01-01

The purpose of this study was to investigate the association between block time and final performance for each sex in 50-m and 100-m individual freestyle, distinguishing between classification (1st to 3rd, 4th to 8th, 9th to 16th) and type of starting platform (old and new) in international competitions. Twenty-six international competitions covering a 13-year period (2000-2012) were analysed retrospectively. The data corresponded to a total of 1657 swimmers’ competition histories. A two-way ANOVA (sex x classification) was performed for each event and starting platform with the Bonferroni post-hoc test, and another two-way ANOVA for sex and starting platform (sex x starting platform). Pearson’s simple correlation coefficient was used to determine correlations between the block time and the final performance. Finally, a simple linear regression analysis was done between the final time and the block time for each sex and platform. The men had shorter starting block times than the women in both events and from both platforms. For 50-m event, medalists had shorter block times than semi- finalists with the old starting platforms. Block times were directly related to performance with the old starting platforms. With the new starting platforms, however, the relationship was inverse, notably in the women’s 50-m event. The block time was related for final performance in the men’s 50- m event with the old starting platform, but with the new platform it was critical only for the women’s 50-m event. Key Points The men had shorter block times than the women in both events and with both platforms. For both distances, the swimmers had shorter block times in their starts from the new starting platform with a back plate than with the old platform. For the 50-m event with the old starting platform, the medalists had shorter block times than the semi-finalists. The new starting platform block time was only determinant in the women’s 50-m event. In order to improve

Infections of Head and Neck Soft Tissues – A Statistical Study over a 10-year Period

Directory of Open Access Journals (Sweden)

Amorin-Remus POPA

2010-09-01

Full Text Available Aim: A statistical analysis of the epidemiology of head and neck soft tissues conditions was carried out. Material and Method: The patients with head and neck infections who received treatment at Ist Oral and Maxillofacial Surgery Clinics of Cluj-Napoca between January 2000 and December 2009 inclusively were included in this study. Results: 1008 patients accomplished the inclusion criteria. The starting point of the head and neck inflammatory conditions was represented mainly by dental-periodontal lesions (79.66%. Most of the infections were localized at the level of a single cavity (81.85%; when more than one cavity was affected the patients were had also systemic conditions. When septic metastases spread the most affected side was the mediastinal structures. All patients included in this study received surgical treatment, most frequently two surgical interventions being necessary (50.20%. The post-surgical evolution was favorable for 1005 patients with an average of hospitalization period of 6.11 days, the hospitalization stay being also influenced by the presence or absence of the systemic immunodepression. Conclusion: The present research identified that the inflammatory conditions of the head and neck have as major starting point the dental-periodontal inflammatory conditions. The surgical treatment is the best choice for curing these affections.

Ipsilateral dislocation of the radial head associated with fracture of distal end of the radius: a case report and review of the literature

Directory of Open Access Journals (Sweden)

Gupta Vinay

2013-06-01

Full Text Available 【Abstract】Dislocation of the radial head in adults is uncommon. A simultaneous dislocation of the radial head and fracture of the ipsilateral distal end of radius with no other associated injuries is extremely rare. As far as we know, such an injury after an unusual mode of injury has been seldom reported in the English literature. We report such a case without any associated injuries or comorbidity. Closed reduction was performed within two hours after injury and results were satisfactory. Immobilisation was continued for 3 weeks. Gradual mobilisation was started after removal of the plaster under the supervision of a physiotherapist. At 6 months’ follow-up, the patient had no residual pain at the elbow with full flexion & extension. Almost full supination with a restriction of last 10 degrees of pronation was achieved. There was no evidence of instability of the elbow. Key words: Radial heads; Dislocations; Radius fractures

Sub-arc narrow gap welding of Atucha 2 RPV closure head

International Nuclear Information System (INIS)

Hantsch, H.; Million, K.; Zimmermann, H.

1982-01-01

Narrow gap technology was used for reasons of design and fabrication when welding the closure-head dome to its flange. Preliminary tests had yielded the necessary improvements of the well-proven sub-arc practice. New facilities had to be developed for welding proper and for the accompanying machining work (finishing in the narrow gap). Special measures were adopted for monitoring the welding process and for recording the welding parameters. The new method was tried out on several large test coupons before welding of the final product was started. No difficulties were encountered during the welding job. Fabrication of the closure head is shown in a short film sequence. (orig.)

Relationship Between Final Performance and Block Times with the Traditional and the New Starting Platforms with A Back Plate in International Swimming Championship 50-M and 100-M Freestyle Events

Directory of Open Access Journals (Sweden)

Antonio Garcia-Hermoso

2013-12-01

Full Text Available The purpose of this study was to investigate the association between block time and final performance for each sex in 50-m and 100-m individual freestyle, distinguishing between classification (1st to 3rd, 4th to 8th, 9th to 16th and type of starting platform (old and new in international competitions. Twenty-six international competitions covering a 13-year period (2000-2012 were analysed retrospectively. The data corresponded to a total of 1657 swimmers’ competition histories. A two-way ANOVA (sex x classification was performed for each event and starting platform with the Bonferroni post-hoc test, and another two-way ANOVA for sex and starting platform (sex x starting platform. Pearson’s simple correlation coefficient was used to determine correlations between the block time and the final performance. Finally, a simple linear regression analysis was done between the final time and the block time for each sex and platform. The men had shorter starting block times than the women in both events and from both platforms. For 50-m event, medalists had shorter block times than semi- finalists with the old starting platforms. Block times were directly related to performance with the old starting platforms. With the new starting platforms, however, the relationship was inverse, notably in the women’s 50-m event. The block time was related for final performance in the men’s 50- m event with the old starting platform, but with the new platform it was critical only for the women’s 50-m event.

Wear resistant performance of highly cross-linked and annealed ultra-high molecular weight polyethylene against ceramic heads in total hip arthroplasty.

Science.gov (United States)

Sato, Taishi; Nakashima, Yasuharu; Akiyama, Mio; Yamamoto, Takuaki; Mawatari, Taro; Itokawa, Takashi; Ohishi, Masanobu; Motomura, Goro; Hirata, Masanobu; Iwamoto, Yukihide

2012-12-01

The purpose of this study was to examine the effects of ceramic femoral head material, size, and implantation periods on the wear of annealed, cross-linked ultra-high molecular weight polyethylene (UHMWPE) (XLPE) in total hip arthroplasty compared to non-cross-linked conventional UHMWPE (CPE). XLPE was fabricated by cross-linking with 60 kGy irradiation and annealing. Femoral heads made from zirconia and alumina ceramics and cobalt-chrome (CoCr) of 22 or 26 mm diameter were used. In this retrospective cohort study, the femoral head penetration into the cup was measured digitally on radiographs of 367 hips with XLPE and 64 hips with CPE. The average follow-up periods were 6.3 and 11.9 years, respectively. Both XLPE creep and wear rates were significantly lower than those of CPE (0.19 mm vs. 0.44 mm, 0.0001 mm/year vs. 0.09 mm/year, respectively). Zirconia displayed increased wear rates compared to alumina in CPE; however, there was no difference among head materials in XLPE (0.0008, 0.00007, and -0.009 mm/year for zirconia, alumina, and CoCr, respectively). Neither head size or implantation period impacted XLPE wear. In contrast to CPE, XLPE displayed low wear rates surpassing the effects of varying femoral head material, size, implantation period, and patient demographics. Further follow-up is required to determine the long-term clinical performance of the annealed XLPE. Copyright © 2012 Orthopaedic Research Society.

Emotional climate, feeding practices, and feeding styles: an observational analysis of the dinner meal in Head Start families.

Science.gov (United States)

Hughes, Sheryl O; Power, Thomas G; Papaioannou, Maria A; Cross, Matthew B; Nicklas, Theresa A; Hall, Sharon K; Shewchuk, Richard M

2011-06-10

A number of studies conducted with ethnically diverse, low-income samples have found that parents with indulgent feeding styles had children with a higher weight status. Indulgent parents are those who are responsive to their child's emotional states but have problems setting appropriate boundaries with their child. Because the processes through which styles impact child weight are poorly understood, the aim of this study was to observe differences in the emotional climate created by parents (including affect, tone of voice, and gestures) and behavioral feeding practices among those reporting different feeding styles on the Caregiver's Feeding Styles Questionnaire. A secondary aim was to examine differences on child weight status across the feeding styles. Participants were 177 Head Start families from Houston, Texas (45% African-American; 55% Hispanic). Using an observational approach, the relationship between the observed emotional climate of the meal, behavioral feeding practices, and self-reported parent feeding styles were examined. Mean age of the children was 4.4 years (SD = 0.7) equally distributed across gender. Families were observed on 3 separate dinner occasions. Heights and weight were measured on the parents and children. Parents with self-reported indulgent feeding styles made fewer demands on their children to eat during dinner and showed lower levels of negative affect and intrusiveness. Surprisingly, these parents also showed higher levels of emotional detachment with their children during dinner. Hispanic boys with indulgent parents had significantly higher BMI z scores compared to Hispanic boys in the other three feeding style groups. No other differences were found on child weight status. Results suggest that the emotional climate created by indulgent parents during dinner and their lack of demands on their children to eat may play an important role in how young children become overweight. Numerous observed emotional climate and behavioral

Radiotherapy in head and neck: a standard treatment?

International Nuclear Information System (INIS)

Santini Blasco, A; Torres Lopez, M; Apardian Manougian, R

1998-01-01

The present work is an exhaustive revision of the literature regarding the employment of combined treatments of radiochemotherapy in the head and neck neoplasms. The sanitary importance of this group of illnesses starts to become remarkable not only due to their frequency but for the high percentage of patients that present themselves for consultation with an advanced illness where the results of the classic treatments of surgery and radiotherapy are discouraging. These results are poor for the survival as well as in the quality of this. It analyzes the role of the different pharmaceuticals used in patients as well as the fundamentally different associations with radiotherapy: neoadjuvant, adjuvant and concomitant. These results allow to affirm that this treatment form is elected for those patients with advanced tumors of head and neck with a general state that allows to tolerate a bigger toxicity [es

Head-Impact–Measurement Devices: A Systematic Review

Science.gov (United States)

O'Connor, Kathryn L.; Rowson, Steven; Duma, Stefan M.; Broglio, Steven P.

2017-01-01

Context: With an estimated 3.8 million sport- and recreation-related concussions occurring annually, targeted prevention and diagnostic methods are needed. Biomechanical analysis of head impacts may provide quantitative information that can inform both prevention and diagnostic strategies. Objective: To assess available head-impact devices and their clinical utility. Data Sources: We performed a systematic search of the electronic database PubMed for peer-reviewed publications, using the following phrases: accelerometer and concussion, head impact telemetry, head impacts and concussion and sensor, head impacts and sensor, impact sensor and concussion, linear acceleration and concussion, rotational acceleration and concussion, and xpatch concussion. In addition to the literature review, a Google search for head impact monitor and concussion monitor yielded 15 more devices. Study Selection: Included studies were performed in vivo, used commercially available devices, and focused on sport-related concussion. Data Extraction: One author reviewed the title and abstract of each study for inclusion and exclusion criteria and then reviewed each full-text article to confirm inclusion criteria. Controversial articles were reviewed by all authors to reach consensus. Data Synthesis: In total, 61 peer-reviewed articles involving 4 head-impact devices were included. Participants in boxing, football, ice hockey, soccer, or snow sports ranged in age from 6 to 24 years; 18% (n = 11) of the studies included female athletes. The Head Impact Telemetry System was the most widely used device (n = 53). Fourteen additional commercially available devices were presented. Conclusions: Measurements collected by impact monitors provided real-time data to estimate player exposure but did not have the requisite sensitivity to concussion. Proper interpretation of previously reported head-impact kinematics across age, sport, and position may inform future research and enable staff clinicians

SU-E-J-12: An Image-Guided Soft Robotic Patient Positioning System for Maskless Head-And-Neck Cancer Radiotherapy: A Proof-Of-Concept Study

International Nuclear Information System (INIS)

Ogunmolu, O; Gans, N; Jiang, S; Gu, X

2015-01-01

Purpose: We propose a surface-image-guided soft robotic patient positioning system for maskless head-and-neck radiotherapy. The ultimate goal of this project is to utilize a soft robot to realize non-rigid patient positioning and real-time motion compensation. In this proof-of-concept study, we design a position-based visual servoing control system for an air-bladder-based soft robot and investigate its performance in controlling the flexion/extension cranial motion on a mannequin head phantom. Methods: The current system consists of Microsoft Kinect depth camera, an inflatable air bladder (IAB), pressured air source, pneumatic valve actuators, custom-built current regulators, and a National Instruments myRIO microcontroller. The performance of the designed system was evaluated on a mannequin head, with a ball joint fixed below its neck to simulate torso-induced head motion along flexion/extension direction. The IAB is placed beneath the mannequin head. The Kinect camera captures images of the mannequin head, extracts the face, and measures the position of the head relative to the camera. This distance is sent to the myRIO, which runs control algorithms and sends actuation commands to the valves, inflating and deflating the IAB to induce head motion. Results: For a step input, i.e. regulation of the head to a constant displacement, the maximum error was a 6% overshoot, which the system then reduces to 0% steady-state error. In this initial investigation, the settling time to reach the regulated position was approximately 8 seconds, with 2 seconds of delay between the command start of motion due to capacitance of the pneumatics, for a total of 10 seconds to regulate the error. Conclusion: The surface image-guided soft robotic patient positioning system can achieve accurate mannequin head flexion/extension motion. Given this promising initial Result, the extension of the current one-dimensional soft robot control to multiple IABs for non-rigid positioning control

SU-E-J-12: An Image-Guided Soft Robotic Patient Positioning System for Maskless Head-And-Neck Cancer Radiotherapy: A Proof-Of-Concept Study

Energy Technology Data Exchange (ETDEWEB)

Ogunmolu, O; Gans, N [The University of Texas at Dallas, Richardson, TX (United States); Jiang, S; Gu, X [UT Southwestern Medical Center, Dallas, TX (United States)

2015-06-15

Purpose: We propose a surface-image-guided soft robotic patient positioning system for maskless head-and-neck radiotherapy. The ultimate goal of this project is to utilize a soft robot to realize non-rigid patient positioning and real-time motion compensation. In this proof-of-concept study, we design a position-based visual servoing control system for an air-bladder-based soft robot and investigate its performance in controlling the flexion/extension cranial motion on a mannequin head phantom. Methods: The current system consists of Microsoft Kinect depth camera, an inflatable air bladder (IAB), pressured air source, pneumatic valve actuators, custom-built current regulators, and a National Instruments myRIO microcontroller. The performance of the designed system was evaluated on a mannequin head, with a ball joint fixed below its neck to simulate torso-induced head motion along flexion/extension direction. The IAB is placed beneath the mannequin head. The Kinect camera captures images of the mannequin head, extracts the face, and measures the position of the head relative to the camera. This distance is sent to the myRIO, which runs control algorithms and sends actuation commands to the valves, inflating and deflating the IAB to induce head motion. Results: For a step input, i.e. regulation of the head to a constant displacement, the maximum error was a 6% overshoot, which the system then reduces to 0% steady-state error. In this initial investigation, the settling time to reach the regulated position was approximately 8 seconds, with 2 seconds of delay between the command start of motion due to capacitance of the pneumatics, for a total of 10 seconds to regulate the error. Conclusion: The surface image-guided soft robotic patient positioning system can achieve accurate mannequin head flexion/extension motion. Given this promising initial Result, the extension of the current one-dimensional soft robot control to multiple IABs for non-rigid positioning control

Biomechanical Analysis of the Swim-Start: A Review

Directory of Open Access Journals (Sweden)

Julien Vantorre, Didier Chollet, Ludovic Seifert

2014-06-01

Full Text Available This review updates the swim-start state of the art from a biomechanical standpoint. We review the contribution of the swim-start to overall swimming performance, the effects of various swim-start strategies, and skill effects across the range of swim-start strategies identified in the literature. The main objective is to determine the techniques to focus on in swimming training in the contemporary context of the sport. The phases leading to key temporal events of the swim-start, like water entry, require adaptations to the swimmer’s chosen technique over the course of a performance; we thus define the swim-start as the moment when preparation for take-off begins to the moment when the swimming pattern begins. A secondary objective is to determine the role of adaptive variability as it emerges during the swim-start. Variability is contextualized as having a functional role and operating across multiple levels of analysis: inter-subject (expert versus non-expert, inter-trial or intra-subject (through repetitions of the same movement, and inter-preference (preferred versus non-preferred technique. Regarding skill effects, we assume that swim-start expertise is distinct from swim stroke expertise. Highly skilled swim-starts are distinguished in terms of several factors: reaction time from the start signal to the impulse on the block, including the control and regulation of foot force and foot orientation during take-off; appropriate amount of glide time before leg kicking commences; effective transition from leg kicking to break-out of full swimming with arm stroking; overall maximal leg and arm propulsion and minimal water resistance; and minimized energy expenditure through streamlined body position. Swimmers who are less expert at the swim-start spend more time in this phase and would benefit from training designed to reduce: (i the time between reaction to the start signal and impulse on the block, and (ii the time in transition (i

Evaluation of the dynamic and kinematic performance of the THOR dummy : neck performance

NARCIS (Netherlands)

Hoofman, M.; van Ratingen, M.R.; Wismans, J.S.H.M.; Cesari, D.

1998-01-01

The objective of this study is to evaluate the frontal head-neck performance of the THOR neck with respect to the human frontal head-neck performance and the Hybrid-III frontal head-neck performance. For this purpose, tests were carried out with an isolated THOR and Hybrid-III head-neck system on a

Head position affects the direction of occlusal force during tapping movement.

Science.gov (United States)

Nakamura, K; Minami, I; Wada, J; Ikawa, Y; Wakabayashi, N

2018-05-01

Despite numerous reports describing the relationship between head position and mandibular movement in human subjects, the direction and magnitude of force at the occlusal contacts have not been investigated in relation to head position. The objective was to investigate the effect of head position on the direction of occlusal force while subjects performed a tapping movement. Twenty-three healthy adult subjects were asked to sit on a chair with their back upright and to perform 15 tapping movements in five different head positions: natural head position (control); forward; backward; and right and left rolled. The direction and magnitude of force were measured using a small triaxial force sensor. The Wilcoxon signed-rank test and Bonferroni test were used to compare head positions in each angle of the anteroposterior axis direction and the lateral axis direction with respect to the superior axis. The force element in the anteroposterior axis shifted to the forward direction in the head position pitched backward, compared with control, pitched forward and rolled left positions (P = .02, tapping movement can be performed in a relaxed position without anteroposterior and lateral loading. © 2018 John Wiley & Sons Ltd.

Variable School Start Times and Middle School Student's Sleep Health and Academic Performance.

Science.gov (United States)

Lewin, Daniel S; Wang, Guanghai; Chen, Yao I; Skora, Elizabeth; Hoehn, Jessica; Baylor, Allison; Wang, Jichuan

2017-08-01

Improving sleep health among adolescents is a national health priority and implementing healthy school start times (SSTs) is an important strategy to achieve these goals. This study leveraged the differences in middle school SST in a large district to evaluate associations between SST, sleep health, and academic performance. This cross-sectional study draws data from a county-wide surveillance survey. Participants were three cohorts of eighth graders (n = 26,440). The school district is unique because SST ranged from 7:20 a.m. to 8:10 a.m. Path analysis and probit regression were used to analyze associations between SST and self-report measures of weekday sleep duration, grades, and homework controlling for demographic variables (sex, race, and socioeconomic status). The independent contributions of SST and sleep duration to academic performance were also analyzed. Earlier SST was associated with decreased sleep duration (χ 2  = 173, p academic performance, and academic effort. Path analysis models demonstrated the independent contributions of sleep duration, SST, and variable effects for demographic variables. This is the first study to evaluate the independent contributions of SST and sleep to academic performance in a large sample of middle school students. Deficient sleep was prevalent, and the earliest SST was associated with decrements in sleep and academics. These findings support the prioritization of policy initiatives to implement healthy SST for younger adolescents and highlight the importance of sleep health education disparities among race and gender groups. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

A Comparative Study of the Influence of Head Teachers Management Styles on Pupils Performance in KCPE in Public and Private Primary Schools in Nakuru Municipality, Kenya

Science.gov (United States)

Shibo, Margaret Nekesa

2016-01-01

The purpose of this study was to compare the influence of management styles of head teacher's on pupils' performance in private and public primary schools in Nakuru municipality at Kenya Certificate of Primary Education level. The population comprised of teachers and head teachers in public primary schools. The study adopted the ex post facto…

Fundamental study on thermo-hydraulics during start-up in natural circulation boiling water reactors, (1)

International Nuclear Information System (INIS)

Aritomi, Masanori; Chiang Jing-Hsien; Takahashi, Tohru; Wataru, Masumi; Mori, Michitsugu.

1992-01-01

Recently, many concepts, in which passive and simplified functions are actively adapted, have been proposed for the next generation LWRs. The natural circulation BWR is one such considered from the requirements for next generation LWRs as compared with current BWRs. It is pointed out from this consideration that a thermo-hydraulic instability, which may appear during start-up, greatly influences concept feasibility because its occurence makes operation for raising power output difficult. Thermo-hydraulic instabilities are investigated experimentally under conditions simulating normal and abnormal start-up processes. It is clarified that three kinds of thermo-hydraulic instabilities may occur during start-up in the natural circulation BWR according to its procedure and reactor configuration, which are (1) geysering induced by condensation, (2) natural circulation instability induced by hydrostatic head fluctuation in steam separators and (3) density wave instability. Driving mechanisms of the geysering and the natural circulation instability, which have never understood enough, are inferred from the results. Finally, the difference of thermo-hydraulic behavior during start-up processes between thermal natural circulation boilers and the Dodewaard reactor is discussed. (author)

Radiographic examination of the equine head

International Nuclear Information System (INIS)

Park, R.D.

1993-01-01

Radiographic examinations of the equine head can be performed with portable x-ray machines. The views comprising the examination depend on the area of the head being examined. With a knowledge of radiographic anatomy and radiographic signs of disease, valuable diagnostic information can be obtained from the radiographic examination. In addition, the radiographic information can also be used to develop a prognosis and determine the most appropriate therapy

Head impact in a snowboarding accident.

Science.gov (United States)

Bailly, N; Llari, M; Donnadieu, T; Masson, C; Arnoux, P J

2017-09-01

To effectively prevent sport traumatic brain injury (TBI), means of protection need to be designed and tested in relation to the reality of head impact. This study quantifies head impacts during a typical snowboarding accident to evaluate helmet standards. A snowboarder numerical model was proposed, validated against experimental data, and used to quantify the influence of accident conditions (speed, snow stiffness, morphology, and position) on head impacts (locations, velocities, and accelerations) and injury risk during snowboarding backward falls. Three hundred twenty-four scenarios were simulated: 70% presented a high risk of mild TBI (head peak acceleration >80 g) and 15% presented a high risk of severe TBI (head injury criterion >1000). Snow stiffness, speed, and snowboarder morphology were the main factors influencing head impact metrics. Mean normal head impact speed (28 ± 6 km/h) was higher than equivalent impact speed used in American standard helmet test (ASTM F2040), and mean tangential impact speed, not included in standard tests, was 13.8 (±7 km/h). In 97% of simulated impacts, the peak head acceleration was below 300 g, which is the pass/fail criteria used in standard tests. Results suggest that initial speed, impacted surface, and pass/fail criteria used in helmet standard performance tests do not fully reflect magnitude and variability of snowboarding backward-fall impacts. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Some thermalhydraulics of closure head adapters in a 3 loops PWR

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, F.; Daubert, O.; Hecker, M. [EDF/DER/National Hydraulics Laboratory, Chatou (France)] [and others

1995-09-01

In 1993 a R&D action, based on numerical simulations and experiments on PWR`s upper head was initiated. This paper presents the test facility TRAVERSIN (a scale model of a 900 MW PWR adapter) and the calculations performed on the geometry of different upper head sections with the Thermalhydraulic Finite Element Code N3S used for 2D and 3D computations. The paper presents the method followed to bring the adapter and upper head study to a successful conclusion. Two complementary approaches are performed to obtain global results on complete fluid flow in the upper head and local results on the flow around the adapters of closure head. A validation test case of these experimental and numerical tools is also presented.

Nintendo Wii remote controllers for head posture measurement: accuracy, validity, and reliability of the infrared optical head tracker.

Science.gov (United States)

Kim, Jongshin; Nam, Kyoung Won; Jang, Ik Gyu; Yang, Hee Kyung; Kim, Kwang Gi; Hwang, Jeong-Min

2012-03-15

To evaluate the accuracy, validity, and reliability of a newly developed infrared optical head tracker (IOHT) using Nintendo Wii remote controllers (WiiMote; Nintendo Co. Ltd., Kyoto, Japan) for measurement of the angle of head posture. The IOHT consists of two infrared (IR) receivers (WiiMote) that are fixed to a mechanical frame and connected to a monitoring computer via a Bluetooth communication channel and an IR beacon that consists of four IR light-emitting diodes (LEDs). With the use of the Cervical Range of Motion (CROM; Performance Attainment Associates, St. Paul, MN) as a reference, one- and three-dimensional (1- and 3-D) head postures of 20 normal adult subjects (20-37 years of age; 9 women and 11 men) were recorded with the IOHT. In comparison with the data from the CROM, the IOHT-derived results showed high consistency. The measurements of 1- and 3-D positions of the human head with the IOHT were very close to those of the CROM. The correlation coefficients of 1- and 3-D positions between the IOHT and the CROM were more than 0.99 and 0.96 (P < 0.05, Pearson's correlation test), respectively. Reliability tests of the IOHT for the normal adult subjects for 1- and 3-D positions of the human head had 95% limits of agreement angles of approximately ±4.5° and ±8.0°, respectively. The IOHT showed strong concordance with the CROM and relatively good test-retest reliability, thus proving its validity and reliability as a head-posture-measuring device. Considering its high performance, ease of use, and low cost, the IOHT has the potential to be widely used as a head-posture-measuring device in clinical practice.

Quad shot - hypofractionated radiotherapy for palliation in advanced squamous cell carcinoma of head and neck

International Nuclear Information System (INIS)

Maqsood, T.; Ali, U.; Arif, S.

2017-01-01

The objective of this study was to determine the efficacy of quad-shot radiation therapy for palliation in locally advanced and metastatic inoperable squamous cell carcinomas of head and neck. Study Design: A quasi-experimental study. Place and Duration of Study: Oncology department, Combined Military Hospital Rawalpindi, from Sep 2012 to Sep 2013. Material and Methods: Thirty five patients were included with histologically confirmed advanced inoperable squamous cell carcinoma in head and neck region, performance status 2 or 3 and survival =3 months. Patients were treated with radiation therapy 14 Gy in four fractions, megavoltage beam, twice daily fractions (at least 6 hours apart), for 2 consecutive days. Symptoms due to cancer (pain and dysphagia) were assessed as per common toxicity criteria adverse event version 4.0 on day 0 before treatment and day 21 after start of treatment. Results: Grades of pain and dysphagia showed significant improvement after treatment with a p-value <0.001. A total of 91.4% patients showed an improvement in grade of pain (32 out of 35 patients) and 45.7% of patients showed improvement in grade of dysphagia (16 out of 35 patients). There was a statistically significant decrease in grades of pain and dysphagia after treatment. Conclusion: The short duration of hypofractionated radiotherapy with Quad Shot was effective with respect to symptom palliation in locally advanced and metastatic inoperable head and neck cancers.

Fall detection in the elderly by head-tracking

OpenAIRE

Yu, Miao; Naqvi, Syed Mohsen; Chambers, Jonathan

2009-01-01

In the paper, we propose a fall detection method based on head tracking within a smart home environment equipped with video cameras. A motion history image and code-book background subtraction are combined to determine whether large movement occurs within the scene. Based on the magnitude of the movement information, particle filters with different state models are used to track the head. The head tracking procedure is performed in two video streams taken bytwoseparatecamerasandthree-dimension...

The study and development of magnetic recording heads. A thin film integrated magnetic head

International Nuclear Information System (INIS)

Lazzari, Jean-Pierre

1970-01-01

A new integrated magnetic head is described. The head was made by vacuum deposition using a mask. A magnetically coupled multilayer construction led to high performance. The results obtained indicate that the device functions equally well, for reading and writing. A set of calculations was developed which could simulate and optimize the behavior of the recording head. The results obtained with the writing were in good agreement with those obtained from experiments and quite different from results which have been several times previously published. In addition a new method was developed for measuring high fields in confined spaces; a 1000 A diameter probe was used in conjunction with a low angle diffraction procedure. The measurements give results which are very different from those obtained by current theories based on the magnetic potentials at the surface. (author) [fr

Wheelchair control by head motion

Directory of Open Access Journals (Sweden)

Pajkanović Aleksandar

2013-01-01

Full Text Available Electric wheelchairs are designed to aid paraplegics. Unfortunately, these can not be used by persons with higher degree of impairment, such as quadriplegics, i.e. persons that, due to age or illness, can not move any of the body parts, except of the head. Medical devices designed to help them are very complicated, rare and expensive. In this paper a microcontroller system that enables standard electric wheelchair control by head motion is presented. The system comprises electronic and mechanic components. A novel head motion recognition technique based on accelerometer data processing is designed. The wheelchair joystick is controlled by the system’s mechanical actuator. The system can be used with several different types of standard electric wheelchairs. It is tested and verified through an experiment performed within this paper.

Influence of Teachers' Personal Health Behaviors on Operationalizing Obesity Prevention Policy in Head Start Preschools: A Project of the Children's Healthy Living Program (CHL).

Science.gov (United States)

Esquivel, Monica Kazlausky; Nigg, Claudio R; Fialkowski, Marie K; Braun, Kathryn L; Li, Fenfang; Novotny, Rachel

2016-05-01

To quantify the Head Start (HS) teacher mediating and moderating influence on the effect of a wellness policy intervention. Intervention trial within a larger randomized community trial. HS preschools in Hawaii. Twenty-three HS classrooms located within 2 previously randomized communities. Seven-month multi-component intervention with policy changes to food served and service style, initiatives for employee wellness, classroom activities for preschoolers promoting physical activity (PA) and healthy eating, and training and technical assistance. The Environment and Policy Assessment and Observation (EPAO) classroom scores and teacher questionnaires assessing on knowledge, beliefs, priorities, and misconceptions around child nutrition and changes in personal health behaviors and status were the main outcome measures. Paired t tests and linear regression analysis tested the intervention effects on the classroom and mediating and moderating effects of the teacher variables on the classroom environment. General linear model test showed greater intervention effect on the EPAO score where teachers reported higher than average improvements in their own health status and behaviors (estimate [SE] = -2.47 (0.78), P teacher health status and behaviors included in a multi-component policy intervention aimed at child obesity prevention may produce a greater effect on classroom environments. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Gait training using a hybrid assistive limb (HAL) attenuates head drop: A case report.

Science.gov (United States)

Miura, Kousei; Koda, Masao; Kadone, Hideki; Kubota, Shigeki; Shimizu, Yukiyo; Kumagai, Hiroshi; Nagashima, Katsuya; Mataki, Kentaro; Fujii, Kengo; Noguchi, Hiroshi; Funayama, Toru; Abe, Tetsuya; Sankai, Yoshiyuki; Yamazaki, Masashi

2018-03-31

Dropped head syndrome (DHS) is characterized by a chin-on-chest deformity, which can severely interfere with forward vision and impair activities of daily living. A standardized treatment strategy for DHS has not been established. To our knowledge, this is the first case report describing the efficacy of gait training using a hybrid assistive limb (HAL) for DHS. A 75-year-old man showed apparent head drop in a standing position, resulting in passively reducible chin-on-chest deformity. A radiograph image showed apparent cervical kyphosis. Center of gravity of the head (CGH)-C7 SVA was +115 mm, CL was -40°, and T1S 39°. The patient underwent a treatment program using HAL, in which gait training was mainly performed, 60 min a day, 5 days a week for 2 weeks (10 sessions). After 2-3 sessions, dropped head started to attenuate. At the end of 10 sessions, the patient was able to walk with normal posture and radiograph images showed cervical kyphosis dramatically decreased because of HAL training. CGH-C7 SVA was 42 mm, CL was -1.7°, and T1S was 30°. Three months' outpatient follow-up revealed a slight deterioration of cervical alignment. However, the patient was able to maintain a better cervical alignment than before HAL training and keep walking with forward vision. There were no complications in any HAL treatment session. In conclusion, gait training using HAL is an option for treatment of DHS in addition to previously reported neck extensor muscle training. Copyright © 2018 Elsevier Ltd. All rights reserved.

Some thermohydraulics of closure head adapters in a 3 loops PWR

International Nuclear Information System (INIS)

Hofmann, F.; Daubert, O.; Bertrand, C.; Hecker, M.; Arnoux-Guisse, F.; Bonnin, O.

1995-12-01

In 1993 a R and D action, based on numerical simulations and experiments on PWR's upper head was initiated. This paper presents the test facility TRAVERSIN (a scale model of a 900 MW adapter) and calculations performed on the geometry of different upper head sections with the Thermalhydraulic Finite Element Code N3S used for 2D and 3D computations. The paper presents the method followed to bring the adapter and upper head study to a successful conclusion. Two complementary approaches are performed to obtain global results on complete fluid flow in the upper head and local results on the flow around the adapters of closure head. A validation test case of these experimental and numerical tools is also presented. (authors). 7 refs., 9 figs., 1 tab

A study using Andrographis paniculata in diet on growth performance of Betong chicken: Starting period

Directory of Open Access Journals (Sweden)

Waree, W.

2007-03-01

Full Text Available An eight-week experiment was conducted to study using Andrographis paniculata (AP on the growth performance of Betong chickens (0-8 weeks of age. Three hundred and fifteen head of 1 day old (mixed sex betong chicks were randomly allotted to 7 dietary treatments, in a completely randomized design experiment. There were three replications in each treatment with 15 chicks per pen. The dietary treatments were 1 basal diet (control, 2 basal diet + 0.1% AP, 3 basal diet + 0.2% AP, 4 basal diet + 0.3% AP, 5 basal diet + 0.5% AP, 6 basal diet + 0.6% AP and 7 basal diet + antibiotic 0.2%, respectively. The results showed no significant (P>0.05 difference among treatments in terms of weight gain, feed intake, feed conversion, mortality rate and feed cost when AP was included up to 0.1-0.3 % of the diet compared with basal diet and basal diet + antibiotic. However, at levels higher than 0.5% AP, it tended to lower growth performance and feed intake thus causing inferior feed conversion ratio. Feed cost was also dramatically increased with the increasing levels of AP in the diet. No significant difference in mortality rate was found among groups. The average mortality was 1.37%.

Head trauma in female professional wrestlers

International Nuclear Information System (INIS)

Nomoto, Jun; Seiki, Yoshikatsu; Nemoto, Masaaki

2007-01-01

The clinical characteristics of head trauma were evaluated in 18 wrestlers belonging to a female professional wrestling organization, 13 regular members and five trainees aged 15-34 years. Medical examinations for head trauma were performed in all wrestlers, and wrestlers treated at our emergency outpatient department were clinically evaluated. In addition, the relationships of head trauma with duration of the wrestling career of 1-16 years (mean 8 years) in the regular members, and less than 1 year in the five trainees, and body mass index (BMI) of 21.0-32.0 in the 16 subjects, excluding two trainees, was evaluated. Chronic symptoms were noted in four of the 18 wrestlers with long wrestling careers (16 years in 1, 13 years in 1, and 5 years in 2). Three wrestlers with symptoms immediately after head trauma showed recurrent retrograde amnesia and had low BMI (21.6, 21.6, and 23.1). Five wrestlers were treated at our emergency outpatient clinic, three required hospitalization and two showed intracranial traumatic changes on computed tomography (acute subdural hematoma in 1 and diffuse brain swelling in 1). Head trauma in female professional wrestlers is associated with longer wrestling career and low BMI. Periodic medical examinations are recommended to monitor for signs of head trauma. (author)

The relationship between start performance and race outcome in elite 500-m short-track speed skating.

Science.gov (United States)

Haug, William B; Drinkwater, Eric J; Mitchell, Lachlan J; Chapman, Dale W

2015-10-01

Initial short-track speed-skating 14-m start performance has substantial influence on 500-m race outcome at the international level, yet the relationship has not been systematically quantified. The purpose of this investigation was to examine the relationship between rank position entering first corner (RPEFC) and race outcome and to understand how this relationship changes with competition round and absolute race intensity. Data were compiled from 2011-2014 World Cup seasons and 2010 and 2014 Olympic Winter Games. Association between RPEFC and race outcome was determined through Kendall tau-rank correlations. A visual comparison was made of how the relationship changes with relative competition level (race tau correlations were sorted by competition round) and with race intensity (race tau correlations were sorted by within-event winning time). A very large relationship between RPEFC and race outcome was observed (correlations for cohort, τ = .60; men, τ = .53; women, τ = .67). When examined by competition round (quarter- to A-finals), no substantial change in relationship was observed (men, τ = .57-.46; women, τ = .73-.53). However, when the start-performance relationship was considered by within-event winning time, the relationship strength increased with decreasing time (men, τ = .61 to .46; women, τ = .76 to .57; fastest to 7th- and 8th-fastest combined, respectively). These results establish and quantify RPEFC as an important aspect of elite short-track 500-m race outcome. RPEFC as an indicator of race outcome becomes increasingly important with absolute race intensity, suggesting that RPEFC capability is a discriminating factor for competitors of similar top speed and speed endurance.

Low head hydro market assessment : main report : vol. 1

International Nuclear Information System (INIS)

2008-03-01

Hydroelectric power is a predictable renewable energy source that produces no greenhouse gases (GHGs) and has low maintenance costs. In addition to river resources, low head hydro is available in sluice gates, irrigation canals, drinking water pressure release valves, and municipal wastewater outfalls. Canada's potential for low head hydro has been estimated at 5000 MW at 2000 different sites across the country. Sites of up to 50 MW have been identified in Ontario and Manitoba. This study performed a market assessment on low head hydro developments. Available and emerging technologies for developing low head hydro were identified. The economics of low head hydro in Canada were explored, and barriers to low head hydro development were identified. Strategies to promote low head hydro development were also explored, and the impact of different incentive types on the low head hydropower market were estimated using a simple economic model. It was concluded that a reduced, streamlined, and standardized environmental assessment process will significantly benefit low head hydro development in Canada. 5 refs., 14 tabs., 17 figs

Emotional climate, feeding practices, and feeding styles: an observational analysis of the dinner meal in Head Start families

Directory of Open Access Journals (Sweden)

Hall Sharon K

2011-06-01

Full Text Available Abstract Background A number of studies conducted with ethnically diverse, low-income samples have found that parents with indulgent feeding styles had children with a higher weight status. Indulgent parents are those who are responsive to their child's emotional states but have problems setting appropriate boundaries with their child. Because the processes through which styles impact child weight are poorly understood, the aim of this study was to observe differences in the emotional climate created by parents (including affect, tone of voice, and gestures and behavioral feeding practices among those reporting different feeding styles on the Caregiver's Feeding Styles Questionnaire. A secondary aim was to examine differences on child weight status across the feeding styles. Methods Participants were 177 Head Start families from Houston, Texas (45% African-American; 55% Hispanic. Using an observational approach, the relationship between the observed emotional climate of the meal, behavioral feeding practices, and self-reported parent feeding styles were examined. Mean age of the children was 4.4 years (SD = 0.7 equally distributed across gender. Families were observed on 3 separate dinner occasions. Heights and weight were measured on the parents and children. Results Parents with self-reported indulgent feeding styles made fewer demands on their children to eat during dinner and showed lower levels of negative affect and intrusiveness. Surprisingly, these parents also showed higher levels of emotional detachment with their children during dinner. Hispanic boys with indulgent parents had significantly higher BMI z scores compared to Hispanic boys in the other three feeding style groups. No other differences were found on child weight status. Conclusions Results suggest that the emotional climate created by indulgent parents during dinner and their lack of demands on their children to eat may play an important role in how young children become

Start-Up Conditions and the Performance of Women – And Men – Controlled Businesses in Manufacturing Industries

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Otilia Driga

2010-06-01

Full Text Available Recent research into the economic performance of women-controlled firms suggests that their underperformance may not be the result of differences in the managerial ability of women as compared to men, and that it may in fact be a consequence of differing levels of start-up resources. Using accounting data, we examine the effects that selected start-up conditions have had on the observed economic performance of a sample of 4450 Spanish manufacturing firms. The results, which indicate significant differences in the initial conditions and show lower levels of assets and employee numbers in women-controlled firms, have implications for the economic performance of such firms. La investigación empírica sobre el desempeño económico de las empresas dirigidas por mujeres sugiere que las diferencias entre este y el desempeño observado en empresas dirigidas por hombres no se debe necesariamente a diferencias entre hombres y mujeres en cuanto a sus habilidades como gerentes de esas empresas sino más bien pueden ser el resultado de las diferencias en las condiciones iniciales en las que se crearon dichas empresas. Usando información contable, este trabajo examina los efectos que algunas condiciones iniciales puedan tener sobre el desempeño económico observado para una muestra de 4450 empresas manufactureras Españolas. Los resultados indican diferencias significativas entre las condiciones iniciales de las empresas dirigidas por mujeres y, respectivamente, por hombres. Para la muestra analizada las empresas dirigidas por mujeres tienen menos activos y un menor número de empleados lo que explica, al menos parcialmente, el menor desempeño en empresas gestionadas por mujeres.

Head orientation prediction: delta quaternions versus quaternions.

Science.gov (United States)

Himberg, Henry; Motai, Yuichi

2009-12-01

Display lag in simulation environments with helmet-mounted displays causes a loss of immersion that degrades the value of virtual/augmented reality training simulators. Simulators use predictive tracking to compensate for display lag, preparing display updates based on the anticipated head motion. This paper proposes a new method for predicting head orientation using a delta quaternion (DQ)-based extended Kalman filter (EKF) and compares the performance to a quaternion EKF. The proposed framework operates on the change in quaternion between consecutive data frames (the DQ), which avoids the heavy computational burden of the quaternion motion equation. Head velocity is estimated from the DQ by an EKF and then used to predict future head orientation. We have tested the new framework with captured head motion data and compared it with the computationally expensive quaternion filter. Experimental results indicate that the proposed DQ method provides the accuracy of the quaternion method without the heavy computational burden.

Bone marrow edema of the femoral head and transient osteoporosis of the hip

International Nuclear Information System (INIS)

Berg, Bruno C. van de; Lecouvet, Frederic E.; Koutaissoff, Sophie; Simoni, Paolo; Malghem, Jacques

2008-01-01

The current article of this issue aims at defining the generic term of bone marrow edema of the femoral head as seen at MR imaging. It must be kept in mind that this syndrome should be regarded, not as a specific diagnosis, but rather as a sign of an ongoing abnormal process that involves the femoral head and/or the hip joint. We aim at emphasizing the role of the radiologists in making a specific diagnosis, starting from a non-specific finding on T1-weighted images and by focusing on ancillary findings on T2-weighted SE or fat-saturated proton-density weighted MR images

Kinematics of the AM-50 heading machine cutting head

Energy Technology Data Exchange (ETDEWEB)

Sikora, W; Bak, K; Klich, R [Politechnika Slaska, Gliwice (Poland). Instytut Mechanizacji Gornictwa

1987-01-01

Analyzes motion of the cutter head of the AM-50 heading machine. Two types of head motion are comparatively evaluated: planar motion and spatial motion. The spatial motion consists of the head rotational motion and horizontal or vertical feed motion, while planar motion consists of rotational motion and vertical feed motion. Equations that describe head motion under conditions of cutter vertical or horizontal feed motion are derived. The angle between the cutting speed direction and working speed direction is defined. On the basis of these formulae variations of cutting speed depending on the cutting tool position on a cutter head are calculated. Calculations made for 2 extreme cutting tools show that the cutting speed ranges from 1,205 m/s to 3,512 m/s. 4 refs.

Subchondral insufficiency fractures of the femoral head

Energy Technology Data Exchange (ETDEWEB)

Davies, M.; Cassar-Pullicino, V.N. [Department of Radiology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, SY10 7AG, Shropshire (United Kingdom); Darby, A.J. [Department of Pathology, Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Oswestry, SY10 7AG, Shropshire (United Kingdom)

2004-02-01

The aim of this study was to increase awareness of, and to show the variable clinical and radiological features of, subchondral insufficiency fractures of the femoral head. The clinical and radiological findings in 7 patients with subchondral insufficiency fractures of the femoral head were reviewed retrospectively. The diagnosis was confirmed histologically in 4 patients. Radiographs were performed in all patients, MRI in 5 and scintigraphy in 4 patients. Radiographs showed varying degrees of femoral head collapse in 4 patients. In the remaining 3 patients radiographs showed a normal femoral head, regional osteoporosis and focal sclerosis, respectively. Magnetic resonance imaging showed a low-signal band on T1- and T2-weighted images in the subchondral bone adjacent or parallel to the articular surface associated with bone marrow oedema. Scintigraphy showed increased uptake in the femoral head. Insufficiency fractures of the femoral head are easily overlooked or confused with avascular necrosis and, when there is significant joint destruction, osteoarthritis. Unsuspected insufficiency fracture of the femoral head can lead to significant and rapid loss of bone stock in osteoporotic patients waiting for arthroplasty for osteoarthritis. Increased awareness of this condition will hopefully lead to earlier diagnosis and a successful outcome of conservative treatment. (orig.)

Comparison of a layered slab and an atlas head model for Monte Carlo fitting of time-domain near-infrared spectroscopy data of the adult head.

Science.gov (United States)

Selb, Juliette; Ogden, Tyler M; Dubb, Jay; Fang, Qianqian; Boas, David A

2014-01-01

Near-infrared spectroscopy (NIRS) estimations of the adult brain baseline optical properties based on a homogeneous model of the head are known to introduce significant contamination from extracerebral layers. More complex models have been proposed and occasionally applied to in vivo data, but their performances have never been characterized on realistic head structures. Here we implement a flexible fitting routine of time-domain NIRS data using graphics processing unit based Monte Carlo simulations. We compare the results for two different geometries: a two-layer slab with variable thickness of the first layer and a template atlas head registered to the subject's head surface. We characterize the performance of the Monte Carlo approaches for fitting the optical properties from simulated time-resolved data of the adult head. We show that both geometries provide better results than the commonly used homogeneous model, and we quantify the improvement in terms of accuracy, linearity, and cross-talk from extracerebral layers.

Start-up test of the prototype heavy water reactor 'FUGEN', (1)

International Nuclear Information System (INIS)

Ando, Hideki; Kawahara, Toshio

1982-01-01

The advanced thermal prototype reactor ''Fugen'' is a heavy water-moderated, boiling light water-cooled power reactor with electric output of 165 MW, which has been developed since 1966 as a national project. The start-up test was begun in March, 1978, being scheduled for about one year, and in March, 1979, it passed the final pre-use inspection and began the full scale operation. In this paper, the result of the start-up test of Fugen is reported. From the experience of the start-up test of Fugen, the following matters are important for the execution of start-up test. 1) Exact testing plan and work schedule, 2) the organization to perform the test, 3) the rapid evaluation of test results and the reflection to next testing plan, and 4) the reflection of test results to rated operation, regular inspection and so on. In the testing plan, the core characteristics peculiar to Fugen, and the features of heavy water-helium system, control system and other equipment were added to the contents of the start-up test of BWRs. The items of the start-up test were reactor physics test, plant equipment performance test, plant dynamic characteristic test, chemical and radiation measurement, and combined test. The organization to perform the start-up test, and the progress and the results of the test are reported. (Kako, I.)

NUMERICAL ANALYSIS OF INFLUENCE OF EXOGENOUS FIRE IN DOG HEADING ON PARAMETERS OF THE AIR STREAM FLOWING THROUGH THIS HEADING

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Magdalena TUTAK

2014-04-01

Full Text Available Flow of ventilation air stream through the dog heading with a fire centre is the flow with complex character, during which as a result of emission of fire gases into the mining atmosphere, there occur to disturbances of its flow. In the paper there is presented a numerical analysis of an influence of exogenous fire in a dog heading, on the parameters of the ventilation air stream flowing through this heading. Modeling tests were carried out with a use of ANSYS software, basing on the Finite Volume Method. For the made assumptions, there were determined physical parameters of air stream flowing through the heading with a fire centre, and also changes in mass fraction of gases in this stream during its flow through the analyzed heading: oxygen, carbon monoxide and carbon dioxide. As a result of performed analysis over the fire centre, the local increase of velocity and temperature and violent decrease of static pressure were recorded. Model of heading presented in the paper gives possibilities for development, and then the analysis of more complicated problems in a range of ventilation of mining headings.

Backstroke start kinematic and kinetic changes due to different feet positioning.

Science.gov (United States)

de Jesus, Karla; de Jesus, Kelly; Figueiredo, Pedro; Gonçalves, Pedro; Pereira, Suzana Matheus; Vilas-Boas, João Paulo; Fernandes, Ricardo Jorge

2013-01-01

The backstroke swimming start international rules changed in 2005. This study compared two backstroke start variants, both with feet parallel to each other but in complete immersion and emersion. Six elite swimmers performed two sets of 4 maximal 15 m bouts, each set using one of the variants. The starts were videotaped in the sagittal plane with two cameras, providing bi-dimensional dual-media kinematic evaluation, and an underwater force plate and a handgrip instrumented with a load cell collected kinetic data. Backstroke start with feet immerged displayed greater centre-of-mass horizontal starting position, centre-of-mass horizontal velocity at hands-off and take-off angle. Backstroke start with feet emerged showed greater wall contact time, centre-of-mass horizontal and downward vertical velocity at take-off, lower limbs horizontal impulse, and centre-of-mass downward vertical velocity during flight phase. Backstroke start with feet immerged and emerged displayed similar centre-of-mass horizontal water reach, back arc angle and 5 m starting time. Irrespective of the swimmer's feet positioning, coaches should emphasise each variant's mechanical advantages during the wall contact phases. Furthermore, the maintenance of those advantages throughout the flight should be stressed for better backstroke start performance.

A novel induction motor starting method using superconduction

International Nuclear Information System (INIS)

Silva, F.B.B.; Orlando, M.T.D.; Fardin, J.F.; Simonetti, D.S.; Baldan, C.A.

2014-01-01

Highlights: • Alternative method for starting up induction motor. • Based on using a high-temperature superconductor. • A prototype of the limiter was constructed with a 2G-YBCO tape. • Prototype was tested with a 55-kW industrial induction motor in a 440-V/60-Hz. • Offers reduced current waveform distortion compared to the soft starter method. - Abstract: In this paper, an alternative method for starting up induction motors is proposed, taking into account experimental measurements. The new starting current limitation method is based on using a high-temperature superconductor. A prototype of the superconducting starting current limiter was constructed with a commercially available second-generation high-temperature superconductor YBCO tape, and this was tested with a 55-kW industrial induction motor in a 440-V/60-Hz three-phase power grid. Performance evaluations of the superconducting limiter method (applied to startup of the induction motor) were performed and were compared with a direct-on-line starter and an electronic soft starter. In addition, a computational model was developed and used for electromagnetic torque analysis of the system. As significant characteristics, our method offers the ability to limit the starting current of the induction motor with greater electromagnetic torque, reduced current waveform distortion and therefore lower harmonic pollution during startup when compared to the soft starter method

A novel induction motor starting method using superconduction

Energy Technology Data Exchange (ETDEWEB)

Silva, F.B.B., E-mail: flaviobarcelos@ifes.edu.br [Ifes – Federal Institute of Espírito Santo, Dept. of Industrial Automation, Serra, ES 29173087 (Brazil); UFES – Federal University of Espírito Santo, Dept. of Electrical Engineering, Vitória, ES (Brazil); Orlando, M.T.D. [UFES – Federal University of Espírito Santo, Dept. of Physics, Vitória, ES (Brazil); Fardin, J.F.; Simonetti, D.S. [UFES – Federal University of Espírito Santo, Dept. of Electrical Engineering, Vitória, ES (Brazil); Baldan, C.A. [EEL/USP – Engineering School from Lorena/University of São Paulo, SP (Brazil)

2014-12-15

Highlights: • Alternative method for starting up induction motor. • Based on using a high-temperature superconductor. • A prototype of the limiter was constructed with a 2G-YBCO tape. • Prototype was tested with a 55-kW industrial induction motor in a 440-V/60-Hz. • Offers reduced current waveform distortion compared to the soft starter method. - Abstract: In this paper, an alternative method for starting up induction motors is proposed, taking into account experimental measurements. The new starting current limitation method is based on using a high-temperature superconductor. A prototype of the superconducting starting current limiter was constructed with a commercially available second-generation high-temperature superconductor YBCO tape, and this was tested with a 55-kW industrial induction motor in a 440-V/60-Hz three-phase power grid. Performance evaluations of the superconducting limiter method (applied to startup of the induction motor) were performed and were compared with a direct-on-line starter and an electronic soft starter. In addition, a computational model was developed and used for electromagnetic torque analysis of the system. As significant characteristics, our method offers the ability to limit the starting current of the induction motor with greater electromagnetic torque, reduced current waveform distortion and therefore lower harmonic pollution during startup when compared to the soft starter method.

Evaluation of the dynamic and kinematic performance of the THOR dummy: neck performance

NARCIS (Netherlands)

Hoofman, M.; Ratingen, M.R. van; Wismans, J.S.H.M.

1998-01-01

The objective of this study is to evaluate the frontal head-neck performance of the THOR neck with respect to the human frontal head-neck performance and the Hybrid-III frontal head-neck performance. For this purpose, tests were carried out with an isolated THOR and Hybrid-III-neck system on a HyGe

Sleep, sleepiness and school start times: a preliminary study.

Science.gov (United States)

Dexter, Donn; Bijwadia, Jagdeep; Schilling, Dana; Applebaugh, Gwendolyn

2003-01-01

High school students are reported to be excessively sleepy, resulting in decreased academic performance, increased psycho-social problems and increased risk of morbidity and mortality from accidents. Early school start times have been noted to contribute to this problem. This report attempts to confirm the relationship of early school start times with decreased sleep and increased sleepiness. We examined sophomore and junior students in 2 local high schools with different start times and measured the amount of time slept and sleepiness. We found that students at the early start school reported reduced sleep time and more sleepiness than their counterparts at the later starting school. Early school start times are associated with student reports of less sleep and increased sleepiness. Further studies in larger groups are recommended in view of the potential significant impact of sleep deprivation in this age group.

Pretreatment Quality of Life Predicts for Locoregional Control in Head and Neck Cancer Patients: A Radiation Therapy Oncology Group Analysis

International Nuclear Information System (INIS)

Siddiqui, Farzan; Pajak, Thomas F.; Watkins-Bruner, Deborah; Konski, Andre A.; Coyne, James C.; Gwede, Clement K.; Garden, Adam S.; Spencer, Sharon A.; Jones, Christopher; Movsas, Benjamin

2008-01-01

Purpose: To analyze the prospectively collected health-related quality-of-life (HRQOL) data from patients enrolled in two Radiation Therapy Oncology Group randomized Phase III head and neck cancer trials (90-03 and 91-11) to assess their value as an independent prognostic factor for locoregional control (LRC) and/or overall survival (OS). Methods and Materials: HRQOL questionnaires, using a validated instrument, the Functional Assessment of Cancer Therapy-Head and Neck (FACT-H and N), version 2, were completed by patients before the start of treatment. OS and LRC were the outcome measures analyzed using a multivariate Cox proportional hazard model. Results: Baseline FACT-H and N data were available for 1,093 patients and missing for 417 patients. No significant difference in outcome was found between the patients with and without baseline FACT-H and N data (p = 0.58). The median follow-up time was 27.2 months for all patients and 49 months for surviving patients. Multivariate analyses were performed for both OS and LRC. Beyond tumor and nodal stage, Karnofsky performance status, primary site, cigarette use, use of concurrent chemotherapy, and altered fractionation schedules, the FACT-H and N score was independently predictive of LRC (but not OS), with p = 0.0038. The functional well-being component of the FACT-H and N predicted most significantly for LRC (p = 0.0004). Conclusions: This study represents, to our knowledge, the largest analysis of HRQOL as a prognostic factor in locally advanced head and neck cancer patients. The results of this study have demonstrated the importance of baseline HRQOL as a significant and independent predictor of LRC in patients with locally advanced head and neck cancer

Is contrast-enhanced CT indicated in acute head injury

International Nuclear Information System (INIS)

Mauser, H.W.; Nieuwenhuizen, O. van; Veiga-Pires, J.A.

1984-01-01

The authors discuss the value of intravenous contrast enhancement in CT scanning in acute head injury. In a series of seventy consecutive patients they conclude that no incremental information was obtained by performing contrast-enhanced CT scans in the acute phase of the head injury. (orig.)

Capabilities of Helmets for Preventing Head Injuries Induced by Ballistic Impacts

Directory of Open Access Journals (Sweden)

D.V. Balandin

2004-01-01

Full Text Available The limiting performance of ballistically loaded helmets designed to reduce head injuries is studied analytically. The projectile does not penetrate the helmet. This analysis evaluates the absolute minimum of the peak displacement of the helmet shell relative to the head, provided that criteria measuring the severity of head injuries lie within prescribed limits. Rather than optimize a specific design configuration, e.g. a viscoelastic foam liner, characteristics of a time-dependent force representing the helmet liner are calculated. The formulation reduces the limiting performance analysis to an optimal control problem.

The effect of dental management for maintaining dental health in patients with head and neck cancer after radiotherapy

International Nuclear Information System (INIS)

Katsura, Kouji; Sasai, Keisuke; Sato, Katsuro; Hayashi, Takafumi; Goto, Sanae; Tomita, Masahiko; Matsuyama, Hiroshi

2009-01-01

The purpose of this study was to evaluate the significance of our dental management protocol by observing the chronological change of dental health of head and neck radiotherapy patients. Fifty-two head and neck radiotherapy patients who had received dental management to prevent and/or alleviate their oral complications were enrolled in this study. They were followed for three or more years after radiotherapy. We divided them into three groups according to the timing of the start of dental management; Pre, Mid and Post. The chronological changes of dental status (DMFT and the number of tooth extractions) and osteoradionecrosis were investigated for three to five years. The increase in the DMFT index of the Pre and Mid groups was reduced to less than 2 by introducing our dental management protocol. On the contrary, the number of unavoidable tooth extractions following radiotherapy was the least in the Pre group. The incidence rates of osteoradionecrosis of the mandible in the Pre, Mid and Post groups were 6.5%, 18.0% and 20.0% respectively. Our dental management protocol was proved to be effective in maintaining dental health and helpful in controlling osteoradionecrosis following head and neck radiotherapy. For a more effective outcome, we advocate that dental management should commence before the start of head and neck radiotherapy. (author)

Opioid-Induced Nausea Involves a Vestibular Problem Preventable by Head-Rest.

Directory of Open Access Journals (Sweden)

Nadine Lehnen

Full Text Available Opioids are indispensable for pain treatment but may cause serious nausea and vomiting. The mechanism leading to these complications is not clear. We investigated whether an opioid effect on the vestibular system resulting in corrupt head motion sensation is causative and, consequently, whether head-rest prevents nausea.Thirty-six healthy men (26.6 ± 4.3 years received an opioid remifentanil infusion (45 min, 0.15 μg/kg/min. Outcome measures were the vestibulo-ocular reflex (VOR gain determined by video-head-impulse-testing, and nausea. The first experiment (n = 10 assessed outcome measures at rest and after a series of five 1-Hz forward and backward head-trunk movements during one-time remifentanil administration. The second experiment (n = 10 determined outcome measures on two days in a controlled crossover design: (1 without movement and (2 with a series of five 1-Hz forward and backward head-trunk bends 30 min after remifentanil start. Nausea was psychophysically quantified (scale from 0 to 10. The third controlled crossover experiment (n = 16 assessed nausea (1 without movement and (2 with head movement; isolated head movements consisting of the three axes of rotation (pitch, roll, yaw were imposed 20 times at a frequency of 1 Hz in a random, unpredictable order of each of the three axes. All movements were applied manually, passively with amplitudes of about ± 45 degrees.The VOR gain decreased during remifentanil administration (p<0.001, averaging 0.92 ± 0.05 (mean ± standard deviation before, 0.60 ± 0.12 with, and 0.91 ± 0.05 after infusion. The average half-life of VOR recovery was 5.3 ± 2.4 min. 32/36 subjects had no nausea at rest (nausea scale 0.00/0.00 median/interquartile range. Head-trunk and isolated head movement triggered nausea in 64% (p<0.01 with no difference between head-trunk and isolated head movements (nausea scale 4.00/7.25 and 1.00/4.5, respectively.Remifentanil reversibly decreases VOR gain at a half

Infant eye and head movements toward the side opposite the cue in the anti-saccade paradigm

Directory of Open Access Journals (Sweden)

Sukigara Masune

2007-01-01

Full Text Available Abstract Background The anti-saccade task, when people must respond in the direction opposite to a visual stimulus, has been used as a marker of operation of the frontal cortical oculomotor area. However, early development of oculomotor control has been little studied with the infant anti-saccade paradigm, and a few studies did not recognize anti-saccades in infants in light of the results of adult anti-saccade. Since the characteristics of infant eye movements are little known, applying the criteria used in adult study is by no means the best way to study infant anti-saccade. As it is indicated that coordinated eye and head movements often enable infants to control the direction of their gaze, head movements should be examined as an infant orienting response. The aim of this study was to address how infants used eye and head movements during the anti-saccade paradigm. To distinguish infants' responses, we also investigated eye and head movements during a task for an inhibition of return. Inhibition of return, in which delayed responses occur in the direction to which attention had previously been oriented, has been thought to mark activity of the superior colliculus. Since the superior colliculus is thought to develop much earlier in life than the frontal lobes, we thought it useful to compare these task performances during infancy. Methods Infants were divided into three groups according to age. Anti-saccade and inhibition-of-return tasks were given. Their eye and head movements during tasks were independently recorded by the corneal reflection method in the head-free condition. Results Younger infants tended to initiate eye movement less than older ones in both tasks. In the anti-saccade task, responses opposite to the cue tended to show longer latency than responses to the cue. Infants made faster responses toward the side opposite the cue when it was to the right than when it was left of fixation. Regarding the comparison of responses

Impulsive force on the head during performance of typical ukemi techniques following different judo throws.

Science.gov (United States)

Hashimoto, Toshihiko; Ishii, Takanori; Okada, Naoyuki; Itoh, Masahiro

2015-01-01

In this study, eight judo athletes who are major candidates for the Japan national team were recruited as participants. Kinematic analysis of exemplary ukemi techniques was carried out using two throws, o-soto-gari, a throw linked to frequent injury, and o-uchi-gari. The aim of this study was to kinematically quantify the timing patterns of exemplary ukemi techniques and to obtain kinematic information of the head, in a sequence of ukemi from the onset of the throw to the completion of ukemi. The results indicated that the vertical velocity with which the uke's head decelerated was reduced by increasing the body surface exposed to the collision with the tatami and by increasing the elapsed time. In particular, overall upper limb contact with the tatami is greatly associated with deceleration. In o-soto-gari, the impulsive force on the faller's head as the head reached the lowest point was 204.82 ± 19.95 kg m · s(-2) while in o-uchi-gari it was 118.46 ± 63.62 kg m · s(-2), z = -1.75, P = 0.08, and it did present a large-sized effect with r = 0.78. These findings indicate that the exemplary o-soto-gari as compared to o-uchi-gari is the technique that causes more significant damage to the uke's head.

The origin and diversification of the developmental mechanisms that pattern the vertebrate head skeleton.

Science.gov (United States)

Square, Tyler; Jandzik, David; Romášek, Marek; Cerny, Robert; Medeiros, Daniel Meulemans

2017-07-15

The apparent evolvability of the vertebrate head skeleton has allowed a diverse array of shapes, sizes, and compositions of the head in order to better adapt species to their environments. This encompasses feeding, breathing, sensing, and communicating: the head skeleton somehow participated in the evolution of all these critical processes for the last 500 million years. Through evolution, present head diversity was made possible via developmental modifications to the first head skeletal genetic program. Understanding the development of the vertebrate common ancestor's head skeleton is thus an important step in identifying how different lineages have respectively achieved their many innovations in the head. To this end, cyclostomes (jawless vertebrates) are extremely useful, having diverged from jawed vertebrates approximately 400 million years ago, at the deepest node within living vertebrates. From this ancestral vantage point (that is, the node connecting cyclostomes and gnathostomes) we can best identify the earliest major differences in development between vertebrate classes, and start to address how these might translate onto morphology. In this review we survey what is currently known about the cell biology and gene expression during head development in modern vertebrates, allowing us to better characterize the developmental genetics driving head skeleton formation in the most recent common ancestor of all living vertebrates. By pairing this vertebrate composite with information from fossil chordates, we can also deduce how gene regulatory modules might have been arranged in the ancestral vertebrate head. Together, we can immediately begin to understand which aspects of head skeletal development are the most conserved, and which are divergent, informing us as to when the first differences appear during development, and thus which pathways or cell types might be involved in generating lineage specific shape and structure. Copyright © 2017 Elsevier Inc. All

Posterior-only spinal fusion without rib head resection for treating type I neurofibromatosis with intra-canal rib head dislocation

Directory of Open Access Journals (Sweden)

Dong Sun

2013-12-01

Full Text Available OBJECTIVES: Patients with Type I neurofibromatosis scoliosis with intra-canal rib head protrusion are extremely rare. Current knowledge regarding the diagnosis and treatment for this situation are insufficient. The purpose of this study is to share our experience in the diagnosis and surgical treatments for such unique deformities. METHODS: Six patients with Type I neurofibromatosis scoliosis with rib head dislocation into the spinal canal were diagnosed at our institution. Posterior instrumentation and spinal fusion without intra-canal rib head resection via a posterior-only approach was performed for deformity correction and rib head extraction. The efficacy and outcomes of the surgery were evaluated by measurements before, immediately and 24 months after the surgery using the following parameters: coronal spinal Cobb angle, apex rotation and kyphosis of the spine and the intra-canal rib head position. Post-operative complications, surgery time and blood loss were also evaluated. RESULTS: Patients were followed up for at least 24 months post-operatively. The three dimensional spinal deformity was significantly improved and the intra-canal rib head was significantly extracted from the canal immediately after the surgery. At follow-up 24 months after surgery, solid fusions were achieved along the fusion segments, and the deformity corrections and rib head positions were well maintained. There were no surgery-related complications any time after the surgery. CONCLUSIONS: Systematic examinations are needed to identify patients with Type I neurofibromatosis scoliosis with rib head dislocation into the canal who can be treated by posterior-only spinal fusion without rib head resection.

The influence of ego depletion on sprint start performance in athletes without track and field experience.

Science.gov (United States)

Englert, Chris; Persaud, Brittany N; Oudejans, Raôul R D; Bertrams, Alex

2015-01-01

We tested the assumption that ego depletion would affect the sprint start in a sample of N = 38 athletes without track and field experience in an experiment by applying a mixed between- (depletion vs. non-depletion) within- (T1: before manipulation of ego depletion vs. T2: after manipulation of ego depletion) subjects design. We assumed that ego depletion would increase the possibility for a false start, as regulating the impulse to initiate the sprinting movement too soon before the starting signal requires self-control. In line with our assumption, we found a significant interaction as there was only a significant increase in the number of false starts from T1 to T2 for the depletion group while this was not the case for the non-depletion group. We conclude that ego depletion has a detrimental influence on the sprint start in athletes without track and field experience.

Why START?

International Nuclear Information System (INIS)

Mendelsohn, J.

1991-01-01

Barring some major unexpected downturn in US-Soviet relations, it seems likely that the long-awaited Strategic Arms Reduction Talks (START) treaty will be signed sometime in 1991. Under negotiation for the past nine years, public acceptance and Senate approval of a START treaty will be facilitated by the generally less confrontational East-West relationship which has evolved over that time, by the growing constraints on the US defense budget, and by the obvious merits of the treaty itself. Not only will the nearly complete START treaty be an extremely useful and powerful arms control agreement, it is also decidedly advantageous to US security interests. First and foremost, a START treaty will cap and reduce the steady buildup of nuclear weapons that has characterized the last 30 years of the US-Soviet strategic relationship. As a result of the basic outline originally agreed to at the Reykjavik summit, START will take a 25 to 35 percent bite out of existing nuclear arsenals, impose approximately a 50 percent cut in overall Soviet ballistic missile warheads and throw-weight (lifting power or payload capacity), and produce an exact 50 percent cut in Soviet SS-18 missiles

Gas Turbine Engine Starting Applicated on TV2-117 Turboshaft

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R. M. Catana

2017-10-01

Full Text Available The paper presents the examination of two different types of engine starting configurations, applicated on TV2-117A turboshaft, running into the test bench. The first type of starting configuration is a normal starting, with the engine connected to the dynamometer which controls the free turbine speed by the dynamometer load. The second type of starting is a different one, the engine is not connected with the dynamometer, therefore it results that there is no control of the free turbine speed from the dynamometer, only from the engine but in particular conditions. To achieve the starting phase an instrumentation scheme is created, to control and monitor the engine, and a starting sequence with all the parameters, confirmations and commands that are involved into the starting phase. The engine starting is performed by the test bench operating system, composed of an acquisition system and a programmable controller, wherewith is running the starting sequence.

Prophylactic treatment of mycotic mucositis in radiotherapy of patients with head and neck cancers

Energy Technology Data Exchange (ETDEWEB)

Koc, M.; Aktas, E. [Ataturk Univ., Erzurum (Turkey). Medical School

2003-02-01

Patients undergoing radiotherapy for head and neck cancer are at increased risk of developing oral candidiasis. The objective of this study was to investigate the clinical Candida mucositis and interruptions in radiotherapy in patients suffering from head and neck cancer, receiving fluconazole in comparison with a control group without specific prophylaxis. Eighty consecutive patients were randomized in a prospective double-blind trial of prophylactic oral fluconazole or treatment with the same drug when mycotic infections appeared. Adult head and neck cancer patients who were undergoing treatment with radiotherapy and/or chemotherapy, radiotherapeutic coverage of the entire oropharynx and oral cavity at least 3 cm anterior to the retromolar trigone and receiving a total dose of more than 6000 cGy and Karnofsky Performance Status (KPS) >70 were included in the study. Group A received radiation therapy plus fluconazole (Fluzole 100 mg/day) starting from the sixth irradiation session throughout the treatment; 40 patients in group B received the same baseline treatment, but were given fluconazole only when mycotic infections appeared. We evaluated 37 patients in group A and the first 37 patients were evaluated in group B. Three of the patients in group A (8.1%) and 14 of the patients in group B (37.8%) demonstrated clinical candidasis. Radiotherapy was interrupted in all of these patients. The differences between the two groups were statistically significant with respect to clinical candidiasis (P=0.005). The median discontinuation time was 5 days (range, 3-7 days) in group A and 7 days (range, 4-10 days) in group B. The median dose resulting in clinical candidiasis was 3200 cGy (range, 2200-5800 cGy) in all groups. In the fluconazole group it was 4200 cGy and in the control group 2800 cGy. These results suggest that patients undergoing head and neck radiation therapy are at risk of developing candidiasis and that fluconazole may be used to reduce the frequency of

Prophylactic treatment of mycotic mucositis in radiotherapy of patients with head and neck cancers

International Nuclear Information System (INIS)

Koc, M.; Aktas, E.

2003-01-01

Patients undergoing radiotherapy for head and neck cancer are at increased risk of developing oral candidiasis. The objective of this study was to investigate the clinical Candida mucositis and interruptions in radiotherapy in patients suffering from head and neck cancer, receiving fluconazole in comparison with a control group without specific prophylaxis. Eighty consecutive patients were randomized in a prospective double-blind trial of prophylactic oral fluconazole or treatment with the same drug when mycotic infections appeared. Adult head and neck cancer patients who were undergoing treatment with radiotherapy and/or chemotherapy, radiotherapeutic coverage of the entire oropharynx and oral cavity at least 3 cm anterior to the retromolar trigone and receiving a total dose of more than 6000 cGy and Karnofsky Performance Status (KPS) >70 were included in the study. Group A received radiation therapy plus fluconazole (Fluzole 100 mg/day) starting from the sixth irradiation session throughout the treatment; 40 patients in group B received the same baseline treatment, but were given fluconazole only when mycotic infections appeared. We evaluated 37 patients in group A and the first 37 patients were evaluated in group B. Three of the patients in group A (8.1%) and 14 of the patients in group B (37.8%) demonstrated clinical candidasis. Radiotherapy was interrupted in all of these patients. The differences between the two groups were statistically significant with respect to clinical candidiasis (P=0.005). The median discontinuation time was 5 days (range, 3-7 days) in group A and 7 days (range, 4-10 days) in group B. The median dose resulting in clinical candidiasis was 3200 cGy (range, 2200-5800 cGy) in all groups. In the fluconazole group it was 4200 cGy and in the control group 2800 cGy. These results suggest that patients undergoing head and neck radiation therapy are at risk of developing candidiasis and that fluconazole may be used to reduce the frequency of

Gender differences in head-neck segment dynamic stabilization during head acceleration.

Science.gov (United States)

Tierney, Ryan T; Sitler, Michael R; Swanik, C Buz; Swanik, Kathleen A; Higgins, Michael; Torg, Joseph

2005-02-01

Recent epidemiological research has revealed that gender differences exist in concussion incidence but no study has investigated why females may be at greater risk of concussion. Our purpose was to determine whether gender differences existed in head-neck segment kinematic and neuromuscular control variables responses to an external force application with and without neck muscle preactivation. Forty (20 females and 20 males) physically active volunteers participated in the study. The independent variables were gender, force application (known vs unknown), and force direction (forced flexion vs forced extension). The dependent variables were kinematic and EMG variables, head-neck segment stiffness, and head-neck segment flexor and extensor isometric strength. Statistical analyses consisted of multiple multivariate and univariate analyses of variance, follow-up univariate analyses of variance, and t-tests (P Gender differences existed in head-neck segment dynamic stabilization during head angular acceleration. Females exhibited significantly greater head-neck segment peak angular acceleration (50%) and displacement (39%) than males despite initiating muscle activity significantly earlier (SCM only) and using a greater percentage of their maximum head-neck segment muscle activity (79% peak activity and 117% muscle activity area). The head-neck segment angular acceleration differences may be because females exhibited significantly less isometric strength (49%), neck girth (30%), and head mass (43%), resulting in lower levels of head-neck segment stiffness (29%). For our subject demographic, the results revealed gender differences in head-neck segment dynamic stabilization during head acceleration in response to an external force application. Females exhibited significantly greater head-neck segment peak angular acceleration and displacement than males despite initiating muscle activity earlier (SCM only) and using a greater percentage of their maximum head-neck segment

Study on transient hydrodynamic performance and cavitation characteristic of high-speed mixed-flow pump

International Nuclear Information System (INIS)

Chen, T; Liu, Y L; Sun, Y B; Wang, L Q; Wu, D Z

2013-01-01

In order to analyse the hydrodynamic performance and cavitation characteristic of a high-speed mixed-flow pump during transient operations, experimental studies were carried out. The transient hydrodynamic performance and cavitation characteristics of the mixed-flow pump with guide vane during start-up operation processes were tested on the pump performance test-bed. Performance tests of the pump were carried out under various inlet pressures and speed-changing operations. The real-time instantaneous external characteristics such as rotational speed, hydraulic head, flow rate, suction pressure and discharge pressure of the pump were measured. Based on the experimental results, the effect of fluid acceleration on the hydrodynamic performances and cavitation characteristics of the mixed-flow pump were analysed and evaluated

‘YES YES HEAD TREMOR’ case developing after cerebellar infarction

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Uygar Utku

2015-12-01

Full Text Available Movement disorders, developing after cerebellar infarctions, are rare. One of them is 'Yes / Yes tremor' head tremor. A 73-year-old female patient was brought to the emergency department of our hospital with complaints of dizziness, nausea and vomiting. There was hypertension on her past history. She was taking anti-hypertension drug. Her neurological examination was normal except for right dysmetria, disdiadikokinesia and damaged knee-heel test. Electrocardiography was atrial fibrillation with rapid ventricular response. On the right cerebellar hemisphere, brain computerized tomography revealed consistent lesions with acute ischemic stroke. The patient showed clinically significant improvement in time and discharged with coumadine. When she came for drug control after two weeks, we detected her ‘Yes / Yes’ revealed style of head tremor started three days ago. The tremor was resting-postural. Its activity increased with excitement, decreased after resting and stopped while sleeping. She was intolerant although we initiated the treatment with primidone 250 mg tablets divided into eight. After continuing the treatment with gabapentine titrated 300 mg tablets, the head tremor of patient improved remarkedly in a short period of time. The phenomenon is presented due to its rarity and remarkableness.

MRI in head trauma

International Nuclear Information System (INIS)

Hong, Jin Kyo

1986-01-01

In the diagnosis of head injury, Magnetic Resonance Imaging (MRI), like CT, is an effective method of distinguishing between intracerebral and extracerebral lesions. In our experience of MRI, early hematomas are almost isointense by Saturation Recovery (SR) method, so these must be performed with Spin Echo (SE) method for better visualization of hematomas. Isodense subdural hematomas, which is a diagnostic dilemma on CT images, are clearly seen on MRI. Delayed hematomas or residual parenchymal lesions are better demonstrated on MRI than on CT. Direct cornal, sagittal images and multiplanar facility of MRI provides excellent visualization of the the location and shape of extracerebral collection of hematoma. For the screening of head traumas, SE method is a technique of choice because of its excellent sensitivity within limited time.

MRI in head trauma

Energy Technology Data Exchange (ETDEWEB)

Hong, Jin Kyo [Shin Wha Hospital, Seoul (Korea, Republic of)

1986-02-15

In the diagnosis of head injury, Magnetic Resonance Imaging (MRI), like CT, is an effective method of distinguishing between intracerebral and extracerebral lesions. In our experience of MRI, early hematomas are almost isointense by Saturation Recovery (SR) method, so these must be performed with Spin Echo (SE) method for better visualization of hematomas. Isodense subdural hematomas, which is a diagnostic dilemma on CT images, are clearly seen on MRI. Delayed hematomas or residual parenchymal lesions are better demonstrated on MRI than on CT. Direct cornal, sagittal images and multiplanar facility of MRI provides excellent visualization of the the location and shape of extracerebral collection of hematoma. For the screening of head traumas, SE method is a technique of choice because of its excellent sensitivity within limited time.

Turbidity Current Head Mixing

Science.gov (United States)

Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

2010-05-01

A laboratory experimental set - up for studying the behaviour of sediment in presence of a turbulent field with zero mean flow is compared with the behaviour of turbidity currents [1] . Particular interest is shown on the initiation of sediment motion and in the sediment lift - off. The behaviour of the turbidity current in a flat ground is compared with the zero mean flow oscilating grid generated turbulence as when wave flow lifts off suspended sediments [2,3]. Some examples of the results obtained with this set-up relating the height of the head of the turbidity current to the equilibrium level of stirred lutoclines are shown. A turbulent velocity u' lower than that estimated by the Shield diagram is required to start sediment motion. The minimum u' required to start sediment lift - off, is a function of sediment size, cohesivity and resting time. The lutocline height depends on u', and the vorticity at the lutocline seems constant for a fixed sediment size [1,3]. Combining grid stirring and turbidty current head shapes analyzed by means of advanced image analysis, sediment vertical fluxes and settling speeds can be measured [4,5]. [1] D. Hernandez Turbulent structure of turbidity currents and sediment transport Ms Thesis ETSECCPB, UPC. Barcelona 2009. [2] A. Sánchez-Arcilla; A. Rodríguez; J.C. Santás; J.M. Redondo; V. Gracia; R. K'Osyan; S. Kuznetsov; C. Mösso. Delta'96 Surf-zone and nearshore measurements at the Ebro Delta. A: International Conference on Coastal Research through large Scale Experiments (Coastal Dynamics '97). University of Plymouth, 1997, p. 186-187. [3] P. Medina, M. A. Sánchez and J. M. Redondo. Grid stirred turbulence: applications to the initiation of sediment motion and lift-off studies Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere. 26, Issue 4, 2001, Pages 299-304 [4] M.O. Bezerra, M. Diez, C. Medeiros, A. Rodriguez, E. Bahia., A. Sanchez-Arcilla and J.M. Redondo. Study on the influence of waves on

Analysis on Sealing Reliability of Bolted Joint Ball Head Component of Satellite Propulsion System

Science.gov (United States)

Guo, Tao; Fan, Yougao; Gao, Feng; Gu, Shixin; Wang, Wei

2018-01-01

Propulsion system is one of the important subsystems of satellite, and its performance directly affects the service life, attitude control and reliability of the satellite. The Paper analyzes the sealing principle of bolted joint ball head component of satellite propulsion system and discuss from the compatibility of hydrazine anhydrous and bolted joint ball head component, influence of ground environment on the sealing performance of bolted joint ball heads, and material failure caused by environment, showing that the sealing reliability of bolted joint ball head component is good and the influence of above three aspects on sealing of bolted joint ball head component can be ignored.

Influence of Head Teachers' General and Instructional Supervisory Practices on Teachers' Work Performance in Secondary Schools in Entebbe Municipality, Wakiso District, Uganda

Science.gov (United States)

Jared, Nzabonimpa Buregeya

2011-01-01

The study examined the Influence of Secondary School Head Teachers' General and Instructional Supervisory Practices on Teachers' Work Performance. Qualitative and qualitative methods with a descriptive-correlational research approach were used in the study. Purposive sampling technique alongside random sampling technique was used to select the…

Dynamic and steady state performance comparison of line-start permanent magnet synchronous motors with interior and surface rotor magnets

Directory of Open Access Journals (Sweden)

Ogbuka Cosmas

2016-03-01

Full Text Available A comprehensive comparison of the dynamic and steady state performance characteristics of permanent magnet synchronous motors (PMSM with interior and surface rotor magnets for line-start operation is presented. The dynamic model equations of the PMSM, with damper windings, are utilized for dynamic studies. Two typical loading scenarios are examined: step and ramp loading. The interior permanent magnet synchronous motor (IPMSM showed superior asynchronous performance under no load, attaining faster synchronism compared to the surface permanent magnet synchronous motor (SPMSM. With step load of 10 Nm at 2 s the combined effect of the excitation and the reluctance torque forced the IPMSM to pull into synchronism faster than the SPMSM which lacks saliency. The ability of the motors to withstand gradual load increase, in the synchronous mode, was examined using ramp loading starting from zero at 2 s. SPMSM lost synchronism at 12 s under 11 Nm load while the IPMSM sustained synchronism until 41 seconds under 40 Nm load. This clearly suggests that the IPMSM has superior load-withstand capability. The superiority is further buttressed with the steady state torque analysis where airgap torque in IPMSM is enhanced by the reluctance torque within 90° to 180° torque angle.

Contrasting Effects of Starting Age and Input on the Oral Performance of Foreign Language Learners

Science.gov (United States)

Muñoz, Carmen

2014-01-01

The present study focuses on the influence of starting age and input on foreign language learning. In relation to starting age, the study investigates whether early starters in instructional settings achieve the same kind of long-term advantage as learners in naturalistic settings and it complements previous research by using data from oral…

A Fast-Starting Robotic Fish

Science.gov (United States)

Modarres-Sadeghi, Yahya; Watts, Matthew; Conte, Joe; Hover, Franz; Triantafyllou, Michael

2009-11-01

We have built a simple mechanical system to emulate the fast-start performance of fish. The system consisted of a thin metal beam covered by a urethane rubber fish body. The body form of the mechanical fish in this work was modeled from a pike species, which is the most successfully studied fast-start specialist species. The mechanical fish was held in curvature and hung in water by two restraining lines, which were simultaneously released by pneumatic cutting mechanisms. The potential energy in the beam was transferred into the fluid, thereby accelerating the fish, similar to a pike. We measured the resulting velocity and acceleration, as well as the efficiency of propulsion for the mechanical fish model and also ran a series of flow visualization tests to observe the resulting flow pattern. We also studied the influence of stiffness and geometry of the tail on the efficiency of propulsion and flow pattern. The hydrodynamic efficiency of the fish, calculated by the transfer of energy, was around 10%. Flow visualization of the mechanical fast-start wake was also analyzed, showing that the acceleration is associated with the fast movement of an intense vortex in a near-lateral direction.

Flued head replacement alternatives

International Nuclear Information System (INIS)

Smetters, J.L.

1987-01-01

This paper discusses flued head replacement options. Section 2 discusses complete flued head replacement with a design that eliminates the inaccessible welds. Section 3 discusses alternate flued head support designs that can drastically reduce flued head installation costs. Section 4 describes partial flued head replacement designs. Finally, Section 5 discusses flued head analysis methods. (orig./GL)

Two-Man Bobsled Push Start Analysis

Directory of Open Access Journals (Sweden)

Lopes Alexandre Dias

2016-04-01

Full Text Available The importance of push start times on bobsled performance was evidenced by some studies, but at this moment there is no article to the authors’ knowledge that describes the bobsled push start. Thus, the objectives of this study were to describe the two-man bobsled push start, analyze the differences between teams, and estimate the most important variable analyzed. We hypothesized that the pilot and brakeman athletes’ movement patterns during a bobsled pushing start can be described. The images used in this study were obtained during the men’s two-man XIV World Championship of Bobsled (2004. Fifteen best teams participating in the championship were recorded, and four start runs for each team were analyzed. The videos were captured by two digital video cameras. The pilot athletes were analyzed during the moment that they touched the lateral push bar of the sled, and the brakemen were analyzed during the first take-off and first landing. The teams were pooled in three groups of five teams using the final ranking of pushing time. We concluded that there was a distinct pattern movement for pilots and brakemen. The initial position of the majority of the pilots was localized slightly behind the bar. After touching the lateral bar, the pilots remained in a semi-squat position, pushing the sled forward in a pattern of marching movement. All brakemen used the board attached to the track as a support for both feet at the start. The brakeman gave the greatest contribution to break the inertia of the sled. There was no significant difference of movement between the three groups analyzed for the pilot and the brakeman.

Economic impact of a head and neck oncologic surgeon: the case mix index.

Science.gov (United States)

Jalisi, Scharukh; Sanan, Akshay; Mcdonough, Katie; Hussein, Khalil; Platt, Michael; Truong, Minh Tam; Couch, Marion; Burkey, Brian B

2014-10-01

Head and neck oncologic surgery is a time-consuming specialty that requires extensive resources and manpower. Case mix index (CMI) is used in evaluating the complexity and economic impact of surgeons. Head and neck oncologic surgeons generate significant revenue for hospitals, yet compensation is relatively low. Retrospective review of a tertiary hospital's case mix data for 605 otolaryngology admissions from 2009 to 2011 was performed. CMI comparison for head and neck oncologic surgeons versus general otolaryngology was performed. In an otolaryngology department of 9 surgeons; there was a significant difference (p 1) favoring head and neck oncologic surgeons. Head and neck oncologic surgeons increase the CMI for hospitals and ultimately influence the hospital's reimbursement. There is a need for increased collaboration between hospitals and departments in fostering and furthering their head and neck surgical oncology programs by taking CMI into consideration. © 2013 Wiley Periodicals, Inc.

Bottom head assembly

International Nuclear Information System (INIS)

Fife, A.B.

1998-01-01

A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs

RA-6 reactor's probabilistic safety evaluation. Identification and selection of starting events

International Nuclear Information System (INIS)

Kay, J.; Chiossi, C.; Felizia, E.; Vallerga, H.; Kalejman, G.; Navarro, R.; Caruso, G.J.

1987-01-01

A summary of the 'Identification and selection of starting events' stage of the previous probabilistic safety evaluation of RA-6 reactor is presented. This evaluation was performed to verify if the safety criteria required for the licensing of RA-6 are met and to promote the diffusion of its meaning and usefulness with educational purposes. At this stage the starting events of RA-6 are determined and the probability that such events occur is calculated. The identification and selection of starting events is performed in two steps: determination of proposed starting events and determination of postulated starting events. The proposed starting events are determined by means of the master logic diagram (MLD) method, while the postulated starting events are obtained by grouping the proposed starting events. The simplifying hypothesis required for the application of MLD to the reactor are also formulated. The probability that the proposed and postulated starting events occur is afterwards calculated, adopting different fault models, in accordance with the nature of events that are considered. Conservative hypothesis on the characteristics of these events and the uncertainty of parameter values of those models are also formulated. The numerical values of the above mentioned probabilities are obtained by giving the parameters suitable values that are extracted from specialized publications. (Author)

On the performance of a high head Francis turbine at design and off-design conditions

International Nuclear Information System (INIS)

Aakti, B; Amstutz, O; Casartelli, E; Romanelli, G; Mangani, L

2015-01-01

In the present paper, fully 360 degrees transient and steady-state simulations of a Francis turbine were performed at three operating conditions, namely at part load (PL), best efficiency point (BEP), and high load (HL), using different numerical approaches for the pressure-velocity coupling. The simulation domain includes the spiral casing with stay and guide vanes, the runner and the draft tube. The main target of the investigations is the numerical prediction of the overall performance of the high head Francis turbine model as well as local and integral quantities of the complete machine in different operating conditions. All results were compared with experimental data published by the workshop organization. All CFD simulations were performed at model scale with a new in-house, 3D, unstructured, object-oriented finite volume code within the framework of the open source OpenFOAM library. The novel fully coupled pressure-based solver is designed to solve the incompressible RANS- Equations and is capable of handling multiple references of frame (MRF). The obtained results show that the overall performance is well captured by the simulations. Regarding the local flow distributions within the inlet section of the draft-tube, the axial velocity is better estimated than the circumferential component

Efficacy of Core Decompression of Femoral Head to Treat Avascular Necrosis in Intravenous Drug Users

Directory of Open Access Journals (Sweden)

Hossein Soleimani

2013-04-01

Full Text Available Core decompression (CD of the femoral head is one of the effective treatments of avascular necrosis (AVN, especially in the early stages of the disease. To investigate further the value of CD in treating the AVN, this study was performed on patients with symptomatic AVN with different etiologies who were treated with CD. This study was carried out on 25 patients (with the total number of 37 femoral head who were diagnosed AVN using X-Ray and MRI. The CD treatments for these patients were started soon after the diagnosis. The results were considered as a success if there was no progression of disease confirmed by X Ray or no subsequent operation was required. Modified Ficat staging was used to record changes before and 2 years after CD treatment. Twenty five patients were participated in this study in which 68% (n=17 were female, 32% (n=8 were male, and the average of the age of the patients were 29.58±4.58. Eight of these patients had systemic lupus erythematous (SLE (32%, 4 rheumatoid arthritis (RA (16%, 3 with kidney transplant (12%, 1 Takayasu’s vasculitis (4% and 1 Wegner vasculitis (4%. Eight of patients had a history of intravenous injection of Temgesic (32%. In patients using Temgesic the changes in Modified Ficat staging were significantly different before and after CD treatment (P=0.03 in comparison with other groups. And in all 8 Temgesic users AVN progressed to the stage 3 and 4 after CD treatment. This study demonstrated that CD treatment to prevent the changes in the femoral head has been more effective in patients with collagen vascular diseases and kidney transplant than patients using intravenous Temgesic. These patients, in spite of early operation, showed no benefit of CD to prevent the changes in the femoral head.

The Sydney Triage to Admission Risk Tool (START): A prospective validation study.

Science.gov (United States)

Ebker-White, Anja A; Bein, Kendall J; Dinh, Michael M

2018-02-08

The present study aims to prospectively validate the Sydney Triage to Admission Risk Tool (START) to predict ED disposition. This was a prospective validation study at two metropolitan EDs in Sydney, Australia. Consecutive triage encounters were observed by a trained researcher and START scores calculated. The primary outcome was patient disposition (discharge or inpatient admission) from the ED. Multivariable logistic regression was used to estimate area under curve of receiver operator characteristic (AUC ROC) for START scores as well as START score in combination with other variables such as frailty, general practitioner referral, overcrowding and major medical comorbidities. There were 894 patients analysed during the study period. The START score when applied to the data had AUC ROC of 0.80 (95% CI 0.77-0.83). The inclusion of other clinical variables identified at triage did not improve the overall performance of the model with an AUC ROC of 0.81 (95% CI 0.78-0.84) in the present study. The overall performance of the START tool with respect to model discrimination and accuracy has been prospectively validated. Further clinical trials are required to test the clinical effectiveness of the tool in improving patient flow and overall ED performance. © 2018 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Study on scan timing using a test injection method in head CTA

International Nuclear Information System (INIS)

Sekito, Yuichi; Sanada, Hidenori

2005-01-01

In head computed tomographic angiography (CTA), circulation from arterial phase to venous phase is more rapid than that in other regions. Therefore, it is necessary to determine correct scan timing to obtain ideal CTA images. A test injection method makes it possible to set correct scan timing from the time density curve (TDC) for each subject. The method, however, has a weak point that is a time lag in an arrival time at peak point of contrast medium on TDC between the test injection and the primary examination because of the difference in total volume of contrast medium used. The purpose of this study calculated the delay time on the TDC in both scans. We used the test injection method and the bolus tracking method in the primary examination. The average errors in start time (Δt1) and slope change time (Δt2) of the contrast medium on the TDC between test injection and primary examination were 0.15 sec and 3.05 sec, respectively. The results indicated that it was important to grasp the delay time in start time and peak arrival time of the contrast medium between test injection and primary examination to obtain ideal images in head CTA. (author)

[Diagnostic and organizational error in head injuries].

Science.gov (United States)

Zaba, Czesław; Zaba, Zbigniew; Swiderski, Paweł; Lorkiewicz-Muszyíska, Dorota

2009-01-01

The study aimed at presenting a case of a diagnostic and organizational error involving lack of detection of foreign body presence in the soft tissues of the head. Head radiograms in two projections clearly demonstrated foreign bodies that resembled in shape flattened bullets, which could not have been missed upon evaluation of the X-rays. On the other hand, description of the radiograms entered by the attending physicians to the patient's medical record indicated an absence of traumatic injuries or foreign bodies. In the opinion of the authors, the case in question involved a diagnostic error: the doctors failed to detect the presence of foreign bodies in the head. The organizational error involved the failure of radiogram evaluation performed by a radiologist.

Split-phase motor running as capacitor starts motor and as capacitor run motor

Directory of Open Access Journals (Sweden)

Yahaya Asizehi ENESI

2016-07-01

Full Text Available In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The magnitude of capacitor that will develop maximum torque in capacitor start motor and capacitor run motor are investigated and determined by simulation. Each of these capacitors is connected to the auxiliary winding of split-phase motor thereby transforming it into capacitor start or capacitor run motor. The starting current and starting torque of the split-phase motor (SPM, capacitor run motor (CRM and capacitor star motor (CSM are compared for their suitability in their operational performance and applications.

Goniometer head

International Nuclear Information System (INIS)

Dzhazairov-Kakhramanov, V.; Berger, V.D.; Kadyrzhanov, K.K.; Zarifov, R.A.

1994-01-01

The goniometer head is an electromechanical instrument that performs the independent transfer of a testing sample on three coordinate axes (X, Y, Z) within limits of ±8 mm and independent rotation relative of these directions. The instrument comprises a sample holder, bellows component and three electrometer drives. The sample holder rotates around the axes X and Y, and is installed on the central arm which rotates around axis Z. One characteristic of this instrument is its independence which allows its use in any camera for researches in the field of radiation physics. 2 figs

Psychomotor performance during a 28 day head-down tilt with and without lower body negative pressure

Science.gov (United States)

Traon, A. Pavy-le; de Feneyrols, A. Rous; Cornac, A.; Abdeseelam, R.; N'uygen, D.; Lazerges, M.; Güell, A.; Bes, A.

Several factors may affect psychomotor performance in space: sensory-motor changes, sleep disturbances, psychological modifications induced by the social isolation and confinement. However, psychomotor performance is difficult to assess. A battery of standardized and computerized tests, so-called "Automated Portable Test System" (APTS) was devised to ascertain the cognitive, perceptive and motor abilities and their possible fluctuations according to environmental effects. Antiorthostatic bedrest, often used to simulate weightlessness, (particularly cardiovascular modifications) also constitutes a situation of social confinement and isolation. During two bedrest experiments (with head-down tilt of -6°) of 28 days each, we intended to assess psychomotor performance of 6 males so as to determine whether: —on the one hand, it could be altered by remaining in decubitus; —on the other, the Lower Body Negative Pressure sessions, designed to prevent orthostatic intolerance back on Earth, could improve the performance. To accomplish this, part of the APTS tests as well as an automated perceptive attention test were performed. No downgrading of psychomotor performance was observed. On the contrary, the tasks were more accurately performed over time. In order to assess the experimental conditions on the acquisition phase, the learning curves were modelled. A beneficial effect of the LBNP sessions on simple tests involving the visual-motor coordination and attention faculties can only be regarded as a mere trend. Methods used in this experiment are also discussed.

Clinical application of duodenum-preserving pancreatic head resection

OpenAIRE

ZHOU Songqiang

2018-01-01

Objective To investigate the indications and therapeutic effect of duodenum-preserving pancreatic head resection (DPPHR). Methods A retrospective analysis was performed for the clinical data of 17 patients who underwent DPPHR in Fujian Provincial Hospital from January 2013 to February 2017. Among these patients, 6 had chronic pancreatitis with pancreatic duct stones, 2 had chronic pancreatitis with pancreatic pseudocyst, 3 had solid pseudopapillary tumor of the pancreatic head, 3 had intraduc...

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 ma...... and the final business model. In other words: The start-up must first nail the problem together with the customers, then develop the solution and test, and then in the end scale it to a full-grown business model.......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...

Results from an experimental trial at a Head Start center to evaluate two meal service approaches to increase fruit and vegetable intake of preschool aged children

Directory of Open Access Journals (Sweden)

Harnack Lisa J

2012-04-01

Full Text Available Abstract Background Strategies to increase fruit and vegetable consumption of preschool aged children are needed. Objectives Evaluate the independent effects of the following meal service strategies on intake of fruits and vegetables of preschool children: 1. Serving fruits and vegetables in advance of other menu items as part of traditional family style meal service; and 2. Serving meals portioned and plated by providers. Methods Fifty-three preschool aged children completed a randomized crossover experiment conducted at a Head Start center in Minneapolis, MN. Over a six week trial period each of the experimental meal service strategies (serving fruits and vegetable first and serving meals portioned by providers was implemented during lunch service for two one-week periods. Two one-week control periods (traditional family style meal service with all menu items served at once were also included over the six week trial period. Childrens lunch intake was observed as a measure of food and nutrient intake during each experimental condition. Results Fruit intake was significantly higher (p Conclusions Serving fruits in advance of other meal items may be a low cost easy to implement strategy for increasing fruit intake in young children. However, serving vegetables first does not appear to increase vegetable intake. Results provide support for current recommendations for traditional family style meal service in preschool settings.

What are Head Cavities? - A History of Studies on Vertebrate Head Segmentation.

Science.gov (United States)

Kuratani, Shigeru; Adachi, Noritaka

2016-06-01

Motivated by the discovery of segmental epithelial coeloms, or "head cavities," in elasmobranch embryos toward the end of the 19th century, the debate over the presence of mesodermal segments in the vertebrate head became a central problem in comparative embryology. The classical segmental view assumed only one type of metamerism in the vertebrate head, in which each metamere was thought to contain one head somite and one pharyngeal arch, innervated by a set of cranial nerves serially homologous to dorsal and ventral roots of spinal nerves. The non-segmental view, on the other hand, rejected the somite-like properties of head cavities. A series of small mesodermal cysts in early Torpedo embryos, which were thought to represent true somite homologs, provided a third possible view on the nature of the vertebrate head. Recent molecular developmental data have shed new light on the vertebrate head problem, explaining that head mesoderm evolved, not by the modification of rostral somites of an amphioxus-like ancestor, but through the polarization of unspecified paraxial mesoderm into head mesoderm anteriorly and trunk somites posteriorly.

MR of head and neck hemangiomas

International Nuclear Information System (INIS)

Bilaniuk, L.T.; Zimmerman, R.A.; Gusnard, D.A.

1990-01-01

This paper defines the MR characteristics of head and neck hemangiomas and to evaluate the role of MR in their diagnosis and management. Eighteen pediatric and young adult patients with head and neck hemangiomas (six neck, six face, three eyelid, two scalp, and one parotid) underwent high-field-strength 1.5-T MR imaging. Conventional spin-echo sequences with T1 and T2 weighting were performed. In addition, one-third of patients underwent MR angiography and gadolinium enhancement. The hemangiomas were isointense to muscle on T1-weighted images and hyperintense on proton-density and T2-weighted images

Development of Head Injury Assessment Reference Values Based on NASA Injury Modeling

Science.gov (United States)

Somers, Jeffrey T.; Melvin, John W.; Tabiei, Ala; Lawrence, Charles; Ploutz-Snyder, Robert; Granderson, Bradley; Feiveson, Alan; Gernhardt, Michael; Patalak, John

2011-01-01

NASA is developing a new capsule-based, crewed vehicle that will land in the ocean, and the space agency desires to reduce the risk of injury from impact during these landings. Because landing impact occurs for each flight and the crew might need to perform egress tasks, current injury assessment reference values (IARV) were deemed insufficient. Because NASCAR occupant restraint systems are more effective than the systems used to determine the current IARVs and are similar to NASA s proposed restraint system, an analysis of NASCAR impacts was performed to develop new IARVs that may be more relevant to NASA s context of vehicle landing operations. Head IARVs associated with race car impacts were investigated by completing a detailed analysis of all of the 2002-2008 NASCAR impact data. Specific inclusion and exclusion criteria were used to select 4071 impacts from the 4015 recorder files provided (each file could contain multiple impact events). Of the 4071 accepted impacts, 274 were selected for numerical simulation using a custom NASCAR restraint system and Humanetics Hybrid-III 50th percentile numerical dummy model in LS-DYNA. Injury had occurred in 32 of the 274 selected impacts, and 27 of those injuries involved the head. A majority of the head injuries were mild concussions with or without brief loss of consciousness. The 242 non-injury impacts were randomly selected and representative of the range of crash dynamics present in the total set of 4071 impacts. Head dynamics data (head translational acceleration, translational change in velocity, rotational acceleration, rotational velocity, HIC-15, HIC-36, and the Head 3ms clip) were filtered according to SAE J211 specifications and then transformed to a log scale. The probability of head injury was estimated using a separate logistic regression analysis for each log-transformed predictor candidate. Using the log transformation constrains the estimated probability of injury to become negligible as IARVs approach

From START to NEW START. The dilemma and future of nuclear disarmament; Von START zu NEW START. Das Dilemma und die Zukunft der Nuklearen Abruestung