These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Spina Bifida Experience  

MedlinePLUS Videos and Cool Tools

... talk about their lives and spina bifida. Related Videos Developing Independence Managing Your Own Medical Care The Importance of Physical Activity More Videos Video Archive Find more NCBDDD videos to watch ...

2

Women's Health and Spina Bifida  

MedlinePLUS

... bladder leakage during sex? In Spina Bifida, bladder function is inseparable from sexual function. Some of the same nerves that control urinary and bowel function are also important in sexual function. Thus, preparing ...

3

Spina Bifida Experience: Developing Independence  

MedlinePLUS

... Independence Your browser does not support iFrames. Related Videos Spina Bifida Experience Managing Your Own Medical Care The Importance of Physical Activity More Videos Video Archive Find more NCBDDD videos to watch ...

4

Spina Bifida Cystica  

PubMed Central

The disappointing results of treatment in 270 consecutive unselected cases of spina bifida admitted during a 27-month period are detailed. Massive effort has led to much avoidable suffering at an exorbitant cost in manpower and money. This study confirms the validity of those adverse prognostic criteria defined in an earlier study and which form a basis for selection. These are (1) thoracolumbar lesions, (2) severe paraplegia, (3) gross enlargement of head, (4) kyphosis, and (5) other severe congenital defects, or birth injuries. It is shown again that selection is possible on the first day of life on purely objective criteria; that it is essential for the benefit of all those affected—whether they are for treatment or no treatment; and that it is in the interest of their families and the community. ImagesFIG. 2.FIG. 3.FIG. 4.FIG. 5.FIG. 6.FIG. 7. PMID:4567074

Lorber, John

1972-01-01

5

MATHEMATICAL DEVELOPMENT IN SPINA BIFIDA  

PubMed Central

Spina bifida (SB) is a neural tube defect diagnosed before or at birth that is associated with a high incidence of math disability often without co-occurring difficulties in reading. SB provides an interesting population within which to examine the development of mathematical abilities and disability across the lifespan and in relation to the deficits in visual-spatial processing that are also associated with the disorder. An overview of math and its cognitive correlates in preschoolers, school-age children and adults with SB is presented including the findings from a longitudinal study linking early executive functions in infancy to the development of later preschool and school age math skills. These findings are discussed in relation to socio-historical perspectives on math education and implications for intervention and directions for further research are presented. PMID:19213013

English, Lianne H.; Barnes, Marcia A.; Taylor, Heather B.; Landry, Susan H.

2011-01-01

6

Orthopedic Management of Spina Bifida  

ERIC Educational Resources Information Center

The management of orthopedic problems in spina bifida has seen a dramatic change over the past 10 years. The negative effects of spasticity, poor balance, and the tethered cord syndrome on ambulatory function are better appreciated. There is less emphasis on the hip radiograph and more emphasis on the function of the knee and the prevention of…

Thomson, Jeffrey D.; Segal, Lee S.

2010-01-01

7

Mathematical Development in Spina Bifida  

ERIC Educational Resources Information Center

Spina bifida (SB) is a neural tube defect diagnosed before or at birth that is associated with a high incidence of math disability often without co-occurring difficulties in reading. SB provides an interesting population within which to examine the development of mathematical abilities and disability across the lifespan and in relation to the…

English, Lianne H.; Barnes, Marcia A.; Taylor, Heather B.; Landry, Susan H.

2009-01-01

8

Spina Bifida Experience: Managing Your Own Medical Care  

MedlinePLUS Videos and Cool Tools

... The Spina Bifida Experience: Managing Your Own Medical Care Your browser does not support iFrames. Source: National ... about how the child participates in his medical care. Related Videos Spina Bifida Experience Developing Independence The ...

9

Spina bifida and anencephaly in Scotland.  

PubMed Central

Data obtained from routine sources showed that from 1971 to 1982 the birth prevalences of spina bifida and anencephaly in Scotland fell. When known terminations after routine alpha fetoprotein screening were added to total births the adjusted birth prevalence could be calculated. In 1974-82 this fell by 40% for spina bifida (3 X 0-1 X 8) and 36% for anencephaly (2 X 2-1 X 4). These findings were compared with data on birth prevalences in England and Wales, Northern Ireland, and Glasgow. The fall in birth prevalences of spina bifida and anencephaly over the past decade appears to have been due both to a true fall in incidence as well as to increased screening and termination for these conditions. PMID:6437477

Carstairs, V; Cole, S

1984-01-01

10

Cerebellar Motor Function in Spina Bifida Meningomyelocele  

Microsoft Academic Search

Spina bifida meningomyelocele (SBM), a congenital neurodevelopmental disorder, involves dysmorphology of the cerebellum, and\\u000a its most obvious manifestations are motor deficits. This paper reviews cerebellar neuropathology and motor function across\\u000a several motor systems well studied in SBM in relation to current models of cerebellar motor and timing function. Children\\u000a and adults with SBM have widespread motor deficits in trunk, upper

Maureen Dennis; Michael S. Salman; Jenifer Juranek; Jack M. Fletcher

2010-01-01

11

Optimizing Health Care for Adults with Spina Bifida  

ERIC Educational Resources Information Center

Survival into adulthood for individuals with spina bifida has significantly improved over the last 40 years with the majority of patients now living as adults. Despite this growing population of adult patients who have increased medical needs compared to the general population, including spina bifida (SB)-specific care, age-related secondary…

Webb, Thomas S.

2010-01-01

12

Identification of novel CELSR1 mutations in spina bifida.  

PubMed

Spina bifida is one of the most common neural tube defects (NTDs) with a complex etiology. Variants in planar cell polarity (PCP) genes have been associated with NTDs including spina bifida in both animal models and human cohorts. In this study, we sequenced all exons of CELSR1 in 192 spina bifida patients from a California population to determine the contribution of CELSR1 mutations in the studied population. Novel and rare variants identified in these patients were subsequently genotyped in 190 ethnically matched control individuals. Six missense mutations not found in controls were predicted to be deleterious by both SIFT and PolyPhen. Two TG dinucleotide repeat variants were individually detected in 2 spina bifida patients but not detected in controls. In vitro functional analysis showed that the two TG dinucleotide repeat variants not only changed subcellular localization of the CELSR1 protein, but also impaired the physical association between CELSR1 and VANGL2, and thus diminished the ability to recruit VANGL2 for cell-cell contact. In total, 3% of our spina bifida patients carry deleterious or predicted to be deleterious CELSR1 mutations. Our findings suggest that CELSR1 mutations contribute to the risk of spina bifida in a cohort of spina bifida patients from California. PMID:24632739

Lei, Yunping; Zhu, Huiping; Yang, Wei; Ross, M Elizabeth; Shaw, Gary M; Finnell, Richard H

2014-01-01

13

Identification of Novel CELSR1 Mutations in Spina Bifida  

PubMed Central

Spina bifida is one of the most common neural tube defects (NTDs) with a complex etiology. Variants in planar cell polarity (PCP) genes have been associated with NTDs including spina bifida in both animal models and human cohorts. In this study, we sequenced all exons of CELSR1 in 192 spina bifida patients from a California population to determine the contribution of CELSR1 mutations in the studied population. Novel and rare variants identified in these patients were subsequently genotyped in 190 ethnically matched control individuals. Six missense mutations not found in controls were predicted to be deleterious by both SIFT and PolyPhen. Two TG dinucleotide repeat variants were individually detected in 2 spina bifida patients but not detected in controls. In vitro functional analysis showed that the two TG dinucleotide repeat variants not only changed subcellular localization of the CELSR1 protein, but also impaired the physical association between CELSR1 and VANGL2, and thus diminished the ability to recruit VANGL2 for cell-cell contact. In total, 3% of our spina bifida patients carry deleterious or predicted to be deleterious CELSR1 mutations. Our findings suggest that CELSR1 mutations contribute to the risk of spina bifida in a cohort of spina bifida patients from California. PMID:24632739

Lei, Yunping; Zhu, Huiping; Yang, Wei; Ross, M. Elizabeth; Shaw, Gary M.; Finnell, Richard H.

2014-01-01

14

Hydrocephalus and Shunts in the Person with Spina Bifida  

MedlinePLUS

... keeping the infant awake; and Any worsening brain function. A head ultrasound, Computed Tomography (CT) scan or ... Spina Bifida closure site; Worsening arm or leg function (increasing weakness or loss of sensation, worsening coordination ...

15

Spina Bifida Experience: The Importance of Physical Activity  

MedlinePLUS Videos and Cool Tools

... Activity Your browser does not support iFrames. Related Videos Spina Bifida Experience Developing Independence Managing Your Own Medical Care More Videos Video Archive Find more NCBDDD videos to watch ...

16

Screening for spina bifida cystica. A cost-benefit analysis.  

PubMed Central

The costs and economic benefits are examined of introducing a programme for the mass-screening of pregnancies for the detection and abortion of fetuses with spina bifida cystica. A benefit-cost index is derived, and the possible effects on it of making different input assumptions are discussed. It is considered that, on economic grounds, screening may be worthwhile only in populations in which the incidence of spina bifida is high. PMID:59616

Hagard, S; Carter, F; Milne, R G

1976-01-01

17

Cerebellar Motor Function in Spina Bifida Meningomyelocele  

PubMed Central

Spina bifida meningomyelocele (SBM), a congenital neurodevelopmental disorder, involves dysmorphology of the cerebellum, and its most obvious manifestations are motor deficits. This paper reviews cerebellar neuropathology and motor function across several motor systems well studied in SBM in relation to current models of cerebellar motor and timing function. Children and adults with SBM have widespread motor deficits in trunk, upper limbs, eyes, and speech articulators that are broadly congruent with those observed in adults with cerebellar lesions. The structure and function of the cerebellum are correlated with a range of motor functions. While motor learning is generally preserved in SBM, those motor functions requiring predictive signals and precise calibration of the temporal features of movement are impaired, resulting in deficits in smooth movement coordination as well as in the classical cerebellar triad of dysmetria, ataxia, and dysarthria. That motor function in individuals with SBM is disordered in a manner phenotypically similar to that in adult cerebellar lesions, and appears to involve similar deficits in predictive cerebellar motor control, suggests that age-based cerebellar motor plasticity is limited in individuals with this neurodevelopmental disorder. PMID:20652468

Dennis, Maureen; Salman, Michael S.; Juranek, Jenifer; Fletcher, Jack M.

2010-01-01

18

Osteoporosis in paediatric patients with spina bifida  

PubMed Central

The prevalence and morbidity associated with osteoporosis and fractures in patients with spina bifida (SB) highlight the importance of osteoporosis prevention and treatment in early childhood; however, the issue has received little attention. The method for the selection of appropriate patients for drug treatment has not been clarified. Objective To review the literature concerning fracture risks and low bone density in paediatric patients with SB. We looked for studies describing state-of-the-art treatments and for prevention of secondary osteoporosis. Methods Articles were identified through a search in the electronic database (PUBMED) supplemented with reviews of the reference lists of selected papers. The main outcome measures were incidence of fractures and risk factors for fracture, an association between bone mineral density (BMD) and occurrence of fracture, risk factors of low BMD, and effects of pharmacological and non-pharmacological treatments on BMD and on the incidence of fractures. We considered as a secondary outcome the occurrence of fractures in relation to the mechanism of injury. Results Results indicated that patients with SB are at increased risk for fractures and low BMD. Risk factors that may predispose patients to fractures include higher levels of neurological involvement, non-ambulatory status, physical inactivity, hypercalciuria, higher body fat levels, contractures, and a previous spontaneous fracture. Limitations were observed in the number and quality of studies concerning osteoporosis prevention and treatment in paediatric patients with SB. The safety and efficiency of drugs to treat osteoporosis in adults have not been evaluated satisfactorily in children with SB. PMID:22330186

Marreiros, Humberto Filipe; Loff, Clara; Calado, Eulalia

2012-01-01

19

Congenital vertebral anomalies: aetiology and relationship to spina bifida cystica.  

PubMed Central

A family survey of 337 patients with congenital vertebral anomalies has been carried out from the Scoliosis Clinics of Edinburgh and the Royal National Orthopaedic Hospital, London. From genetic and epidemiological evidence it is clear that multiple vertebral anomalies (without apparent spina bifida) are aetiologically related to anencephaly and spina bifida cystics, carrying a 5-10% risk to subsequent sibs for any one of these defects. The implications for prenatal diagnosis are discussed. Solitary hemivertebrae and localized anterior defects of the vertebral bodies causing kyphoscoliosis are sporadic (non-familial) in nature, carrying no risk to subsequent sibs. Images PMID:1100836

Wynne-Davies, R

1975-01-01

20

Latex Allergy and Sensitization in Children with Spina bifida  

Microsoft Academic Search

Background: The purpose of this study was to investigate the prevalence rate of latex sensitization and latex allergy among children with spina bifida and to evaluate risk factors for natural rubber latex hypersensitivity. Methods: A total of 34 children between 2.5 and 17 years of age participated in the study. Participants completed a questionnaire and underwent skin prick tests with

Andrzej Obojski; Jacek Chodorski; Wojciech Barg; Andrzej M. Fal

2002-01-01

21

Correlates of Self Esteem in Adolescents with Spina Bifida.  

ERIC Educational Resources Information Center

The study examined correlates of self-esteem in 54 adolescents and young adults (ages 12-22) with spina bifida. Core issues identified were the relationships of global self-esteem and perceived competencies in specific areas, perceptions of control, and identification with the physically handicapped. Relationships of self-esteem to age, gender,…

Eckart, M. L.

22

Neurobehavioral outcomes in spina bifida: Processes versus outcomes  

PubMed Central

We review neurobehavioral outcomes and interventions for children with spina bifida. Focusing on children with spina bifida myelomeningocele, we contrast historical views of outcomes based on comparisons across content domains (e.g., language versus visual perceptual skills) with a view based on overarching processes that underlie strengths and weakness within content domains. Thus, we suggest that children with SBM have strengths when the skill involves the capacity to retrieve information from semantic memory and generate material that has been associatively linked or learned (associative processing) and general difficulties on tasks that require the construction or integration of a response (assembled processing). We use a hypothetical case to illustrate the differences in content domains versus general processes and also identify interventions that may be effective in addressing some of the cognitive and behavioral difficulties experienced variably by people with SBM. We extend these general principles to a discussion of variability in outcomes and use data from a large sample of children with spina bifida to illustrate the basis for this variability. PMID:20798790

Fletcher, Jack M.; Ostermaier, Kathryn K.; Cirino, Paul T.; Dennis, Maureen

2010-01-01

23

Executive functioning and psychological adjustment in children and youth with spina bifida  

Microsoft Academic Search

Children and adolescents with spina bifida are at risk for poor neuropsychological functioning and psychological outcomes. The relationship between executive functioning and psychological adjustment is an area worthy of investigation in this population. The current study assessed executive functioning and psychological outcomes in a group of children and adolescents with spina bifida (SBM) (n?=?51) and nondisabled controls (n?=?45). A mediation

Natalie C. Kelly; Robert T. Ammerman; Joseph R. Rausch; M. Douglas Ris; Keith O. Yeates; Sonya G. Oppenheimer; Benedicta G. Enrile

2011-01-01

24

Executive functioning and psychological adjustment in children and youth with spina bifida  

Microsoft Academic Search

Children and adolescents with spina bifida are at risk for poor neuropsychological functioning and psychological outcomes. The relationship between executive functioning and psychological adjustment is an area worthy of investigation in this population. The current study assessed executive functioning and psychological outcomes in a group of children and adolescents with spina bifida (SBM) (n?=?51) and nondisabled controls (n?=?45). A mediation

Natalie C. Kelly; Robert T. Ammerman; Joseph R. Rausch; M. Douglas Ris; Keith O. Yeates; Sonya G. Oppenheimer; Benedicta G. Enrile

2012-01-01

25

Heterogeneity of muscle fat infiltration in children with spina bifida  

PubMed Central

Children with spina bifida have well recognized functional deficits of muscle, but little is known about the associated changes in muscle anatomy and composition. This study used water-fat magnetic resonance imaging (MRI) to measure fat infiltration in the lower extremity muscles of 11 children with myelomeningocele, the most severe form of spina bifida. MRI measurements of muscle fat fraction (FF) were compared against manual muscle test (MMT) scores for muscle strength. The FF measurements were objective and reliable with mean inter-rater differences of <2% and intraclass correlation coefficients > 0.98. There was a significant inverse relationship between muscle FF and MMT scores (P ? 0.001). Surprisingly, however, muscles with negligible strength (MMT 0–1) exhibited a bimodal distribution of FF with one group having FF > 70% and another group having FF < 20%. The MRI also revealed striking heterogeneity amongst individual muscles in the same muscle group (e.g., 4% fat in one participant’s lateral gastrocnemius vs. 88% in her medial gastrocnemius), as well as significant asymmetry in FF in one participant with asymmetric strength and sensation. These results suggest that quantitative water-fat MRI may serve as a biomarker for muscle degeneration which may reveal subclinical changes useful for predicting functional potential and prognosis. PMID:24169376

Wren, Tishya A.L.; Ponrartana, Skorn; Van Speybroeck, Alexander; Ryan, Deirdre D.; Chia, Jonathan M.; Hu, Houchun H.

2013-01-01

26

The Impact of Family, Peer, and School Contexts on Depressive Symptoms in Adolescents with Spina Bifida  

PubMed Central

Objective Based on social ecological theory, this study examined the joint relations among adolescents’ family, peer, and school contexts and depressive symptoms in youth with spina bifida using cumulative, protective, and specific effects models. Method Sixty families of adolescents with spina bifida and 65 comparison families reported on adolescent’s positive experiences within these contexts and on depressive symptoms when youth were 14–15 and 16–17 years old. Results Adolescents with spina bifida had fewer total positive contexts and less positive experience within peer and school contexts, as compared to typically developing adolescents. Greater total number of positive contexts and higher levels of positive experiences within family and school contexts were associated with fewer depressive symptoms for both groups; peer positive experiences were related to lower depressive symptoms for typically developing adolescents only. Conclusion Adolescents with spina bifida have fewer positive contexts, which may place them at risk for higher levels of depressive symptoms. PMID:21171793

Essner, Bonnie S.; Holmbeck, Grayson N.

2010-01-01

27

Development of the skeleton in normal rats and in rats with trypan blue induced spina bifida.  

PubMed

In this study skeletal abnormalities in trypan blue induced axial dysraphic disorders were investigated and compared with the normal ontogenesis of the rat skeleton. The first appearance and developmental sequence of the cartilaginous and osseous structures in embryos and fetuses of normal dams were described and discussed in relation to the literature. Two main types of spina bifida were found in the offspring of trypan blue treated dams: open and occult spina bifida. Vertebral abnormalities in open spina bifida fetuses were most frequently present in the lower thoracic region and were always accompanied by rib malformations. In occult spina bifida on the contrary the abnormalities in the vertebral arches were mainly restricted to the sacral region. Both types of spina bifida were accompanied by hypoplastic tails. Apart from a delay in the onset and progress of ossification no other skeletal abnormalities were seen following trypan blue treatment. A human fetus with spina bifida was X-rayed and the vertebral abnormalities detected were very similar to those in rat fetuses. PMID:7020357

Peters, P W; Verhoef, A; De Liefde, A; Berkvens, J M

1981-03-01

28

Results of selective treatment of spina bifida cystica.  

PubMed Central

The results of selective treatment in 120 infants with open spina bifida, admitted between May 1971 and December 1976, were prospectively studied. Seventy-one infants had adverse criteria at birth and were not treated. They all died, more than 90% of them within 6 months of birth. Seven had meningocele. All were treated and survived without handicap. Forty-two infants with myelomeningocele were actively treated. Thirty-six survive at follow-up after 3 to 9 years. The quality of survival is much better than when selection was not used but 8 children have moderate or severe handicaps. The parents were fully informed and consulted at every decision-making step; they fully supported the principle of selection and the action taken on behalf of their own child. PMID:6458248

Lorber, J; Salfield, S A

1981-01-01

29

Survival and handicap of infants with spina bifida.  

PubMed Central

A follow-up study was carried out on 213 infants born with spina bifida cystica (including encephalocele and occipital meningocele) from 1965 to 1972 to women resident in Oxfordshire and the western part of Berkshire. The 5-year survival rate was 36% (39/107) for those with open lesions, 60% (30/50) for those with closed ones, and 18% (10/56) for those with lesions which could not be classified (not known) but which were probably nearly all open. The extent of handicap among these survivors was assessed by means of criteria described by Lorber; among those with open lesions (including 'not known') 84% (41/49) were severely handicapped, 10% (4/49) were moderately handicapped, and only 6% (3/49) had no handicap; among those with closed lesions, 37% (11/30) were severely handicapped, 33% (10/30) were moderately handicapped, and the remaining 30% (9/30) were not handicapped. Closed head lesions (encephalocele or occipital meningocele) were more often associated with severe handicap (6/8; 75%) than were closed spinal lesions (5/22; 23%). The children with open lesions who survived for at least 5 years spent, on average, at least 6 months in hospital during the first 5 years of their life and had, on average, at least 6 major surgical operations. In comparison, those with closed lesions spent one-third less time in hospital, and had fewer than half as many operations. During the period of the study a selective treatment policy was adopted typical of that commonly practised now, and all the infants were born before antenatal screening had been introduced. Our results therefore may be helpful in assessing the benefits to be expected from antenatal screening for open spina bifida. PMID:7436454

Althouse, R; Wald, N

1980-01-01

30

Long-term outcome in open spina bifida.  

PubMed Central

BACKGROUND: Doctors need reliable data on outcome in order to help parents faced with difficult decisions about termination of an affected pregnancy or treatment after birth. AIM: To determine survival, health and lifestyle at the mean age of 30 years in a complete cohort of adults born with open spina bifida. DESIGN OF STUDY: Prospective cohort study. PARTICIPANTS: Well-documented cohort of 117 consecutive cases of open spina bifida whose backs were closed non-selectively at birth between 1963 and 1971. METHOD: Survivors (age range = 26 to 33 years) were surveyed by postal questionnaire and telephone interview. The main outcome measures were the health, independence and lifestyle of the survivors in terms of living in the community, driving a car and working in open employment. RESULTS: Ascertainment was 100%. Sixty (51%) had died, mainly the most disabled. Of the 57 survivors, 84% had a cerebrospinal fluid (CSF) shunt, 70% had an IQ of 80 or more, 37% lived independently in the community, 39% drove a car, 30% could walk more than 50 metres and 26% were in open employment. However one-third (19) still needed daily care, three were on respiratory support, two were blind, two had diabetes mellitus, and one was on dialysis. Mortality, disability and achievement reflected the neurological deficit that had been recorded in infancy in terms of sensory level. Attainment and independence were reduced in those who had needed revision of CSF shunt. CONCLUSION: The survivors in this unselected cohort showed a wide range of outcome from apparent normality to very severe disability. This reflected both the extent of their original neurological deficit and events in the history of their CSF shunt. PMID:14601340

Oakeshott, Pippa; Hunt, Gillian M

2003-01-01

31

Mutations in planar cell polarity gene SCRIB are associated with spina bifida.  

PubMed

Neural tube defects (NTDs) (OMIM #182940) including anencephaly, spina bifida and craniorachischisis, are severe congenital malformations that affect 0.5-1 in 1,000 live births in the United States, with varying prevalence around the world. Mutations in planar cell polarity (PCP) genes are believed to cause a variety of NTDs in both mice and humans. SCRIB is a PCP-associated gene. Mice that are homozygous for the Scrib p.I285K and circletail (Crc) mutations, present with the most severe form of NTDs, namely craniorachischisis. A recent study reported that mutations in SCRIB were associated with craniorachischisis in humans, but whether SCRIB mutations contribute to increased spina bifida risk is still unknown. We sequenced the SCRIB gene in 192 infants with spina bifida and 190 healthy controls. Among the spina bifida patients, we identified five novel missense mutations that were predicted-to-be-deleterious by the PolyPhen software. Of these five mutations, three of them (p.P1043L, p.P1332L, p.L1520R) significantly affected the subcellular localization of SCRIB. In addition, we demonstrated that the craniorachischisis mouse line-90 mutation I285K, also affected SCRIB subcellular localization. In contrast, only one novel missense mutation (p.A1257T) was detected in control samples, and it was predicted to be benign. This study demonstrated that rare deleterious mutations of SCRIB may contribute to the multifactorial risk for human spina bifida. PMID:23922697

Lei, Yunping; Zhu, Huiping; Duhon, Cody; Yang, Wei; Ross, M Elizabeth; Shaw, Gary M; Finnell, Richard H

2013-01-01

32

Interhemispheric Effective and Functional Cortical Connectivity Signatures of Spina Bifida Are Consistent with Callosal Anomaly  

PubMed Central

Abstract The impact of the posterior callosal anomalies associated with spina bifida on interhemispheric cortical connectivity is studied using a method for estimating cortical multivariable autoregressive models from scalp magnetoencephalography data. Interhemispheric effective and functional connectivity, measured using conditional Granger causality and coherence, respectively, is determined for the anterior and posterior cortical regions in a population of five spina bifida and five control subjects during a resting eyes-closed state. The estimated connectivity is shown to be consistent over the randomly selected subsets of the data for each subject. The posterior interhemispheric effective and functional connectivity and cortical power are significantly lower in the spina bifida group, a result that is consistent with posterior callosal anomalies. The anterior interhemispheric effective and functional connectivity are elevated in the spina bifida group, a result that may reflect compensatory mechanisms. In contrast, the intrahemispheric effective connectivity is comparable in the two groups. The differences between the spina bifida and control groups are most significant in the ? and ? bands. PMID:22571349

Malekpour, Sheida; Li, Zhimin; Cheung, Bing Leung Patrick; Castillo, Eduardo M.; Papanicolaou, Andrew C.; Kramer, Larry A.; Fletcher, Jack M.

2012-01-01

33

Trajectories of Family Processes across the Adolescent Transition in Youth with Spina Bifida  

PubMed Central

The current study investigated change in family processes, including conflict, cohesion, and stress, across the adolescent transition, comparing the developmental trajectories of youth with and without spina bifida. Individual growth curve modeling procedures were utilized to describe the developmental course of family processes across 4 waves of data collection, from ages 9 to 15, and to test whether illness status [spina bifida vs. matched comparison group (N = 68 for both groups at Time 1)] would significantly predict individual variability in family processes. Potential moderators (child gender, SES, and child verbal ability) of the association between illness status and family functioning were also examined. Differences were found between the trajectories of family processes for families of youth with and without spina bifida. For families of youth with spina bifida, changes in family conflict and cohesion may be less dramatic than or inconsistent with what is expected during typical adolescence. Families of youth with spina bifida from low SES homes appear to demonstrate resilience in terms of family stress. PMID:19803608

Jandasek, Barbara; Holmbeck, Grayson N.; DeLucia, Christian; Zebracki, Kathy; Friedman, Deborah

2009-01-01

34

Complications following breast cancer therapy in the adult spina bifida population: A case report  

PubMed Central

Survival to adulthood in spina bifida has greatly increased with the advent of modern therapies. With this prolonging of life expectancy, patients are exposed to the risk of adult onset malignancies and the complications of subsequent treatment. We present the case of a 66-year-old woman born with a terminal lipomyelomeningocele, presenting with new fecal incontinence and a desire to undivert her ileal conduit. The deterioration was attributed to chemotherapy for breast cancer. We highlight the urologic challenges of breast cancer management in the neurogenic bowel population, as well as the utility of an adult spina bifida clinic. To the best of our knowledge, this is the first case report of a spina bifida patient presenting with fecal and urinary complications from breast cancer chemotherapy. PMID:24282472

Hoy, Nathan Y.; Metcalfe, Peter

2013-01-01

35

Transcallosal connectivity and cortical rhythms: findings in children with spina bifida  

PubMed Central

We studied the relation between cortical oscillatory rhythms and the structural integrity of the corpus callosum in 21 children with spina bifida and hydrocephalus. Participants underwent resting state neuromagnetic recordings and diffusion tensor imaging. Areas of three segments of the corpus callosum (genu, body, splenium) were derived through diffusion tensor imaging-based morphometrics. Children with spina bifida showed reduced values of spectral power in the ?, ? and ? bands when compared with age-matched controls, but only in the posterior and temporal regions. Reduced spectral power in posterior regions correlated with decreased area of the posterior segments of the corpus callosum. Atypical cortical oscillatory activity is associated with reduced transcallosal connectivity in children with spina bifida. PMID:19690505

Castillo, Eduardo M.; Fletcher, Jack M.; Li, Zhimin; Hoskison, Mayre M.; Hasan, Khader M.; Passaro, Anthony; Papanicolaou, Andrew C.

2011-01-01

36

Motor Contingency Learning and Infants with Spina Bifida  

PubMed Central

Infants with Spina Bifida (SB) were compared to typically developing infants (TD) using a conjugate reinforcement paradigm at 6 months-of-age (n = 98) to evaluate learning, and retention of a sensory-motor contingency. Analyses evaluated infant arm-waving rates at baseline (wrist not tethered to mobile), during acquisition of the sensory-motor contingency (wrist tethered), and immediately after the acquisition phase and then after a delay (wrist not tethered), controlling for arm reaching ability, gestational age, and socioeconomic status. Although both groups responded to the contingency with increased arm-waving from baseline to acquisition, 15% to 29% fewer infants with SB than TD were found to learn the contingency depending on the criterion used to determine contingency learning. In addition, infants with SB who had learned the contingency had more difficulty retaining the contingency over time when sensory feedback was absent. The findings suggest that infants with SB do not learn motor contingencies as easily or at the same rate as TD infants, and are more likely to decrease motor responses when sensory feedback is absent. Results are discussed with reference to research on contingency learning in infants with and without neurodevelopmental disorders, and with reference to motor learning in school-age children with SB. PMID:23298791

Taylor, Heather B.; Barnes, Marcia A.; Landry, Susan H.; Swank, Paul; Fletcher, Jack M.; Huang, Furong

2014-01-01

37

Quantitative diffusion tensor imaging and intellectual outcomes in spina bifida  

PubMed Central

Object Patients with spina bifida (SB) have variable intellectual outcomes. The authors used diffusion tensor (DT) imaging to quantify whole-brain volumes of gray matter, white matter, and cerebrospinal fluid (CSF), and perform regional quantitative microstructural assessments of gray matter nuclei and white matter tracts in relation to intellectual outcomes in patients with SB. Methods Twenty-nine children with myelomeningoceles and 20 age- and sex-matched children with normal neural tube development underwent MR imaging with DT image acquisition and assessments of intelligence. The DT imaging-derived metrics were the fractional anisotropy (FA), axial (parallel), and transverse (perpendicular) diffusivities. These metrics were also used to segment the brain into white matter, gray matter, and CSF. A region-of-interest analysis was conducted of the white and gray matter structures implicated in hydrocephalus. Results The amount of whole-brain gray matter was decreased in patients with SB, with a corresponding increase in CSF (p < 0.0001). Regional transverse diffusivity in the caudate nucleus was decreased (p < 0.0001), and the corresponding FA was increased (p < 0.0001), suggesting reduced dendritic branching and connectivity. Fractional anisotropy in the posterior limb of the internal capsule increased in the myelomeningocele group (p = 0.02), suggesting elimination of some divergent fascicles; in contrast, the FA in several white matter structures (such as the corpus callosum genu [p < 0.001] and arcuate fasciculus) was reduced, suggesting disruption of myelination. Diffusion tensor imaging-metrics involving gray matter volume and the caudate nucleus, but not other structures, predicted variations in IQ (r = 0.37-0.50; p < 0.05). Conclusions Diffusion tensor imaging-derived metrics provide noninvasive neuronal surrogate markers of the pathogenesis of SB and predict variations in general intellectual outcomes in children with this condition. PMID:18590401

Hasan, Khader M.; Sankar, Ambika; Halphen, Christopher; Kramer, Larry A.; Ewing-Cobbs, Linda; Dennis, Maureen; Fletcher, Jack M.

2011-01-01

38

[Peri- and postoperative management for minimally invasive fetoscopic surgery of spina bifida].  

PubMed

Minimally invasive fetoscopic surgery for spina bifida has been developed to improve the postnatal neurological function of affected fetuses -and to achieve a reduced maternal trauma compared to open fetal surgery. This -article gives an overview on the peri- and postoperative management of such cases at our centre. PMID:25518829

Degenhardt, J; Axt-Fliedner, R; Enzensberger, C; Tenzer, A; Kawecki, A; Kohl, T

2014-12-01

39

Epidemiologic and Genetic Aspects of Spina Bifida and Other Neural Tube Defects  

ERIC Educational Resources Information Center

The worldwide incidence of neural tube defects (NTDs) ranges from 1.0 to 10.0 per 1,000 births with almost equal frequencies between two major categories: anencephaly and spina bifida (SB). Epidemiological studies have provided valuable insight for (a) researchers to identify nongenetic and genetic factors contributing to etiology, (b) public…

Au, Kit Sing; Ashley-Koch, Allison; Northrup, Hope

2010-01-01

40

Transition to Adult Health Care for Adolescents with Spina Bifida: Research Issues  

ERIC Educational Resources Information Center

The increasing survival of children and young people with congenital disabilities such as spina bifida (SB) provides a challenge to health care systems globally about how best to respond to the multitude of health, developmental, and psychosocial needs of those affected by this complex disorder across the lifespan, not just in childhood and…

Sawyer, Susan M.; Macnee, Sarah

2010-01-01

41

Quality of Life in Individuals with Spina Bifida: A Research Update  

ERIC Educational Resources Information Center

Quality of life (QOL) is an important concept for individuals with chronic health conditions. Measuring and supporting QOL in children, adolescents, and adults with spina bifida (SB) may be especially unique given the broad range of complex health and rehabilitative challenges they encounter. This article provides a research update on (a)…

Sawin, Kathleen J.; Bellin, Melissa H.

2010-01-01

42

The impact of folic acid intake on the association between diabetes, obesity, and spina bifida  

PubMed Central

Objective To investigate the relationship between spina bifida and two established risk factors, pregestational diabetes and obesity, in both the presence and absence of the recommended daily folic acid intake in the periconceptional period. Study Design Cases of spina bifida (n=1154) and controls (n=9439) from the Slone Epidemiology Center Birth Defects Study (1976–2011) were included. Information on preexisting diabetes (collected 1976+) and obesity (collected 1993+), defined as BMI ?30 kg/m2, were collected through interviews conducted within six months of delivery. Periconceptional folic acid intake was calculated using both dietary and supplement information. Mothers were classified as consuming more or less than 400µg/day of folic acid, with food folate included at a 30% discount for its lower bioavailability. Logistic regression models, adjusted for maternal race, education, and study site, were used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the joint effects of low folic acid intake coupled with diabetes or obesity. Results Mothers of cases were more likely to have diabetes or be obese (0.7% and 19.0%, respectively) than control mothers (0.4% and 10.8%, respectively). The joint effect of diabetes and lower folic acid intake on spina bifida was larger (aOR:3.95; CI: 1.56, 10.00) than that of diabetes and higher folic acid intake (aOR:1.31; CI: 0.17, 10.30). Folic acid intake made little difference on the association between obesity and spina bifida. Conclusion Our findings suggest that folic acid further attenuates, though does not eliminate, the risk of spina bifida associated with diabetes, than that with obesity. PMID:23711668

Parker, Samantha E; Yazdy, Mahsa M; Tinker, Sarah C; Mitchell, Allen A; Werler, Martha M

2013-01-01

43

Partial agenesis of the corpus callosum in spina bifida meningomyelocele and potential compensatory mechanisms  

PubMed Central

After a review of Arthur Benton’s conceptual and methodological contributions to the understanding of normal and pathological development, we discuss agenesis of the corpus callosum (CC), criteria for potential neuroanatomical compensatory mechanisms in CC agenesis, and the results of an examination of magnetic resonance imaging (MRI) data of the CC in 193 children with spina bifida meningomyelocele (SBM). There were 26 CC regional patterns. Although complete agenesis did not occur, partial agenesis was observed in 102 children and within 15 CC regional patterns. Only 4.1% had a normal CC. Quantitative assessment of the area of the CC in 26 NC children and 68 children with SBM revealed that all subgroups with CC anomalies had smaller areas than did a subgroup with a normal CC. Areas were especially small in rostral/splenial agenesis and splenial agenesis but larger with rostral agenesis. Subgroups with normal/hypoplastic regions or complete hypoplasia also had CC areas that were smaller than normal but larger than the areas for the splenial agenesis groups. The relative rarity of anterior commissure enlargement (3.1%) and longitudinal bundles of Probst (0.1%) suggest that these particular fiber tract anomalies are unlikely candidates for structural compensatory mechanisms. The hippocampal commissure, enlarged in 13%, may be a more promising candidate. Overall, however, the functionality of anomalous fiber tracts and commissures in SBM is yet to be determined. PMID:19052950

Hannay, H. Julia; Dennis, Maureen; Kramer, Larry; Blaser, Susan; Fletcher, Jack M.

2009-01-01

44

Bladder dysfunction and neurological disability at presentation in closed spina bifida  

PubMed Central

Congenital closed spinal anomalies are associated with distortion of the spinal cord, the spinal nerve roots or both, and can result in neurological abnormalities of the lower limbs and neuropathic bladder dysfunction. This study reports clinical and videourodynamic findings in a group of 51 patients with closed spina bifida. The mean age at presentation to a specialist neurourological clinic was 3.3 years. Twenty five patients presented with urinary tract disturbance and 12 presented with neurological problems. Thirty three had normal neurological examination or only minor objective signs, 21 had normal renal tract ultrasonography but only two patients had normal videourodynamics, with 31 having two or more abnormalities during this assessment. Neither clinical neurological assessment nor the history of voiding behaviour are reliable indicators of bladder dysfunction and subsequent risk of renal damage. Therefore, all patients with a known or suspected diagnosis of closed spina bifida should have videourodynamic assessment.?? PMID:9771249

Johnston, L; Borzyskowski, M

1998-01-01

45

Pituitary gland and axial skeletal malformations in human fetuses with spina bifida.  

PubMed

The purpose of the present study was to describe the pituitary gland and axial skeleton, including the sella turcica, in human fetuses with spina bifida. Ten fetuses with gestational ages (GA) 15 1/2-28 weeks were investigated radiographically (Faxitron X-ray apparatus) and immunohistochemically. Four of the fetuses have been described previously. The study showed that nine fetuses had minor or no skeletal abnormalities in the vertebral bodies of the spine, and one fetus had severely malformed vertebral bodies. In all cases the sella turcica and the pituitary gland were malformed. Adenopituitary tissue was in all cases located in both the sella turcica and the pharyngeal submucosa. The most severe sella turcica/pituitary gland malformation was seen in the fetus with the malformed spine. The connection between the prenatally registered sella turcica/pituitary gland malformation and the endocrinological status of children with spina bifida should be emphasized in future studies. PMID:10661842

Kjaer, I; Fischer Hansen, B; Reintoft, I; Keeling, J W

1999-12-01

46

The use of self-modeling to improve the swimming performance of spina bifida children.  

PubMed Central

The use of edited videotape replay (which showed only "positive" behaviors) to improve the water skills of three spina bifida children, aged 5 to 10 years was examined. A multiple baseline across subjects design was used, and behavioral changes were observed to occur in close association with intervention. One child was given successive reapplications of videotaped self-modeling with continuing improvements. It appears that a useful practical technique has been developed. PMID:6988381

Dowrick, P W; Dove, C

1980-01-01

47

Predisposition to spina bifida: Search for a relation to maternal gastric acid secretion.  

PubMed Central

The peak acid output of the stomach in a group of 71 mothers of spina bifida children and in 71 matched controls was estimated indirectly by the serum level of group I pepsinogens. The mean levels did not differ significantly, suggesting that the conjectured teratogen is not specially acid-labile. The variance was significantly higher in index subjects than in controls, but the interpretation of this finding is not clear. PMID:563466

Stanway, P A; Samloff, I M; Brace, C J; Renwick, J H

1977-01-01

48

Non-surgical Intervention of Knee Flexion Contracture in Children with Spina Bifida: Case Report  

PubMed Central

[Purpose] The purpose of this case report is to describe for the first time, the use of serial casting in the management of knee joint flexion contracture for a young child with spina bifida. [Case Description] The child was 6?years old, and had L3–L4 spina bifida level lesion with quadriceps muscle strength grade 3 +. The child had previously received weekly physiotherapy including stretching for knee flexion contracture on both lower limbs, but without improvement. [Results] The knee flexion contracture, which was not corrected with passive stretching, improved with casting from ?40° knee extension to ?5° knee extension as measured by a standard goniometer over a period of 4 weeks. Careful measures were taken to ensure skin integrity. At follow up after one-year, the child could ambulate independently with the help of walking aids. [Conclusion] The outcome indicates that using serial casting and follow-up with the use of bracing may be useful for enhancing the walking ability of a young child with spina bifida with knee flexion contractures. Further investigations of serial casting as well as investigation of serial casting with other interventions are warranted. PMID:24926155

Al-Oraibi, Saleh

2014-01-01

49

Distribution of affected muscles and degree of neurogenic lesion in patients with spina bifida  

PubMed Central

Introduction Patients with spina bifida in the lumbosacral region usually have various degrees of motor and sensory dysfunctions of the lower extremities and anal sphincter. The aim of our study was to evaluate the distribution and differences in frequencies of affected muscles, number of affected muscles and degree of neurogenic lesion between patients with spina bifida occulta (SBO) and spina bifida aperta (SBA). Material and methods In 100 patients with SB, 6 muscles in the lower limbs were separately analysed. Due to the number of affected muscles, we evaluated 5 groups of patients: with 1 affected muscle, 2 affected muscles, 3 affected muscles, 4 affected muscles and 5 affected muscles. Three degrees of neurogenic lesions were assessed: mild, moderate and severe. Results The tibialis anterior muscle was most frequently affected in SB patients. The outer anal sphincter was frequently affected in the group of SBA patients. Single muscle affection is frequent in the group of patients with SBO, while in the group of patients with SBA, 4 muscles were significantly frequently affected. The great majority of patients (45.46%) with affected outer anal sphincter (OAS) in the group of SBO were without affection of other muscles, while for the SBA group it was for every third patient. Mild neurogenic lesion was significantly frequent in SBO patients, while severe form was significantly frequent in SBA patients. Conclusions Patients with SBO usually present with mild to moderate clinical presentation, while multiple root involvement and severe degree of neurogenic lesion is associated more frequently with SBA. PMID:22328890

Petronic, Ivana; Nikolic, Dejan; Cirovic, Dragana; Cvjeticanin, Suzana; Knezevic, Tatjana; Raicevic, Mirjana; Brdar, Radivoj; Dzamic, Dragana; Janic, Nenad; Golubovic, Zoran

2011-01-01

50

Rare case of spina bifida in both twins with possible genetic basis.  

PubMed

Neural tube defects (NTD) are a group of congenital malformations of the brain and spine, the etiology of which is still debated. Although presumed to be the consequence of interactions between genetic and environmental factors, so far, it is not known which genes are involved in the pathogenesis of these malformations. NTD affecting both fetuses in a twin gestation is a rare event. In view of this rarity, we present a case of dichorionic diamniotic twin pregnancy with spina bifida in both fetuses concordantly. This gestation was preceeded by another dichorionic diamniotic twin pregnancy that was complicated by placental abruption. PMID:21790891

Lembet, Arda; U?urlu, Evin Nil; Toprak, Taner; Bastu, Ercan

2011-11-01

51

Spina bifida: a multidisciplinary perspective on a many-faceted condition.  

PubMed

Open spina bifida or myelomeningocele (SBM) is the most common birth defect involving the central nervous system, second only in incidence to congenital cardiac disease. Outcomes in this disorder were poor until the mid-20th century, when modern neurosurgical techniques (closing the lesion and treating hydrocephalus) and treatment for the neuropathic bladder addressed the major causes of mortality, although SBM may still be poorly treated in the developing world. Initial management - or mismanagement - has a profound impact on survival and long-term quality of life. PMID:24897828

Fieggen, G; Fieggen, K; Stewart, C; Padayachy, L; Lazarus, J; Donald, K; Dix-Peek, S; Toefy, Z; Figaji, A

2014-03-01

52

A unifying hypothesis for hydrocephalus, Chiari malformation, syringomyelia, anencephaly and spina bifida  

PubMed Central

This work is a modified version of the Casey Holter Memorial prize essay presented to the Society for Research into Hydrocephalus and Spina Bifida, June 29th 2007, Heidelberg, Germany. It describes the origin and consequences of the Chiari malformation, and proposes that hydrocephalus is caused by inadequate central nervous system (CNS) venous drainage. A new hypothesis regarding the pathogenesis, anencephaly and spina bifida is described. Any volume increase in the central nervous system can increase venous pressure. This occurs because veins are compressible and a CNS volume increase may result in reduced venous blood flow. This has the potential to cause progressive increase in cerebrospinal fluid (CSF) volume. Venous insufficiency may be caused by any disease that reduces space for venous volume. The flow of CSF has a beneficial effect on venous drainage. In health it moderates central nervous system pressure by moving between the head and spine. Conversely, obstruction to CSF flow causes localised pressure increases, which have an adverse effect on venous drainage. The Chiari malformation is associated with hindbrain herniation, which may be caused by low spinal pressure relative to cranial pressure. In these instances, there are hindbrain-related symptoms caused by cerebellar and brainstem compression. When spinal injury occurs as a result of a Chiari malformation, the primary pathology is posterior fossa hypoplasia, resulting in raised spinal pressure. The small posterior fossa prevents the flow of CSF from the spine to the head as blood enters the central nervous system during movement. Consequently, intermittent increases in spinal pressure caused by movement, result in injury to the spinal cord. It is proposed that posterior fossa hypoplasia, which has origins in fetal life, causes syringomyelia after birth and leads to damage to the spinal cord in spina bifida. It is proposed that hydrocephalus may occur as a result of posterior fossa hypoplasia, where raised pressure occurs as a result of obstruction to flow of CSF from the head to the spine, and cerebral injury with raised pressure occurs in anencephaly by this mechanism. The current view of dysraphism is that low central nervous system pressure and exposure to amniotic fluid, damage the central nervous system. The hypothesis proposed in this essay supports the view that spina bifida is a manifestation of progressive hydrocephalus in the fetus. It is proposed that that mesodermal growth insufficiency influences both neural tube closure and central nervous system pressure, leading to dysraphism. PMID:18405364

Williams, Helen

2008-01-01

53

The relationship between intelligence and academic achievements in spina bifida adolescents.  

PubMed

I.Q. scores taken at sixteen years were significantly related to external examination results in both spina bifida and control groups. An I.Q. of 110 or more was associated with a high probability of GCE passes and an I.Q. under 90 with no passes. Three interrelated factors were responsible for poor academic achievement. These were: special school attendance shunt insertion, and severe physical handicap Only 6% of the aggressively treated children in this study are likely to enter higher education; those leaving school without qualifications and a physical handicap are much more likely to be unemployed. PMID:6395544

Tew, B; Laurence, K M

1984-12-01

54

Frequency of purchase and associated costs of assistive technology for Washington State Medicaid program enrollees with spina bifida by age  

Microsoft Academic Search

BackgroundAssistive technology (AT) is one strategy to mitigate or eliminate barriers to independence for individuals with disabilities, including those with spina bifida (SB). However, little is known about current use and costs of AT for people with SB, including the cost burden to medical insurance payees.

Alyssa M. Bamer; Frederick A. Connell; Brian J. Dudgeon; Kurt L. Johnson

2010-01-01

55

CHKA and PCYT1A gene polymorphisms, choline intake and spina bifida risk in a California population  

PubMed Central

Background Neural tube defects (NTDs) are among the most common of all human congenital defects. Over the last two decades, accumulating evidence has made it clear that periconceptional intake of folic acid can significantly reduce the risk of NTD affected pregnancies. This beneficial effect may be related to the ability of folates to donate methyl groups for critical physiological reactions. Choline is an essential nutrient and it is also a methyl donor critical for the maintenance of cell membrane integrity and methyl metabolism. Perturbations in choline metabolism in vitro have been shown to induce NTDs in mouse embryos. Methods This study investigated whether single nucleotide polymorphisms (SNPs) in human choline kinase A (CHKA) gene and CTP:phosphocholine cytidylytransferase (PCYT1A) gene were risk factors for spina bifida. Fluorescence-based allelic discrimination analysis was performed for the two CHKA intronic SNPs hCV1562388 (rs7928739) and hCV1562393, and PCYT1A SNP rs939883 and rs3772109. The study population consisted of 103 infants with spina bifida and 338 non-malformed control infants who were born in selected California counties in the period 1989–1991. Results The CHKA SNP hCV1562388 genotypes with at least one C allele were associated with a reduced risk of spina bifida (odds ratio = 0.60, 95%CI = 0.38–0.94). The PCYT1A SNP rs939883 genotype AA was associated with a twofold increased risk of spina bifida (odds ratio = 1.89, 95% CI = 0.97–3.67). These gene-only effects were not substantially modified by analytic consideration to maternal periconceptional choline intake. Conclusion Our analyses showed genotype effects of CHKA and PCYT1A genes on spina bifida risk, but did not show evidence of gene-nutrient interactions. The underlying mechanisms are yet to be resolved. PMID:17184542

Enaw, James O Ebot; Zhu, Huiping; Yang, Wei; Lu, Wei; Shaw, Gary M; Lammer, Edward J; Finnell, Richard H

2006-01-01

56

The Kennedy Krieger Independence Scales–Spina Bifida Version: A Measure of Executive Components of Self-Management  

PubMed Central

Purpose/Objective Successful implementation of functional self-care skills depends upon adequate executive functioning; however, many scales assessing adaptive skills do not address the inherent executive burden of these tasks. This omission is especially relevant for individuals with spina bifida, for whom medical self-care tasks impose a significant burden requiring initiation and prospective memory. The Kennedy Krieger Independence Scales–Spina Bifida Version (KKIS–SB) is a caregiver-reported measure designed to address this gap; it assesses skills for managing both typical and spina bifida-related daily self-care demands, with a focus on the timely and independent initiation of adaptive skills. Research Method/Design Parents of 100 youth and young adults with spina bifida completed the KKIS–SB. Exploratory factor analysis and Pearson's correlations were used to assess the factor structure, reliability, and construct validity of the KKIS–SB. Results The scale demonstrates excellent internal consistency (Cronbach's alpha = .891). Exploratory factor analysis yielded four factors, explaining 65.1% of the total variance. Two primary subscales were created, initiation of routines and prospective memory, which provide meaningful clinical information regarding management of a variety of typical (e.g., get up on time, complete daily hygiene routines on time) and spina bifida-specific self-care tasks (e.g., begin self-catheterization on time, perform self-examination for pressure sores). Conclusions/Implications Based upon internal consistency estimates and correlations with measures of similar constructs, initial data suggest good preliminary reliability and validity of the KKIS–SB. PMID:23438006

Jacobson, Lisa A.; Tarazi, Reem A.; McCurdy, Mark D.; Schultz, Scott; Levey, Eric; Mahone, E. Mark; Zabel, T. Andrew

2014-01-01

57

Hydrothorax Due to Ventriculopleural Shunting in a Child with Spina Bifida on Chronic Dialysis: Third Ventriculostomy as an Alternative of Cerebrospinal Diversion  

Microsoft Academic Search

The purpose of this paper is to describe the risks of ventriculopleural shunt in patients with spina bifida and end-stage-renal-diseases (ESRD), and to describe endoscopic third ventriculostomy as an alternative for the combination of cerebrospinal shunt and dialysis modality. We report a 16-year-old boy with spina bifida on chronic dialysis with a massive unilateral hydrothorax and respiratory distress complicating a

Jose Grunberg; Anabella Rébori; María Cristina Verocay; Virginia Ramela; Ricardo Alberti; Alvaro Cordoba

2005-01-01

58

Perception of strong-meter and weak-meter rhythms in children with spina bifida meningomyelocele  

PubMed Central

Neurodevelopmental disorders such as spina bifida meningomyelocele (SBM) are often associated with dysrhythmic movement. We studied rhythm discrimination in 21 children with SBM and in 21 age-matched controls, with the research question being whether both groups showed a strong-meter advantage whereby rhythm discrimination is better for rhythms with a strong-meter, in which onsets of longer intervals occurred on the beat, than those with a weak-meter, in which onsets of longer intervals occurred off the beat. Compared to controls, the SBM group was less able to discriminate strong-meter rhythms, although they performed comparably in discriminating weak-meter rhythms. The attenuated strong-meter advantage in children with SBM shows that their rhythm deficits occur at the level of both perception and action, and may represent a central processing disruption of the brain mechanisms for rhythm. PMID:19573270

HOPYAN, TALAR; SCHELLENBERG, E. GLENN; DENNIS, MAUREEN

2011-01-01

59

Fetal Surgery: The Ochsner Experience with In Utero Spina Bifida Repair  

PubMed Central

Background Myelomeningocele is the most common form of congenital central nervous system defect that is compatible with life. Most patients with myelomeningocele have significant functional impairment of ambulation and bowel and bladder function, require permanent cerebrospinal fluid diversion with shunting, and have significant morbidity and mortality from hindbrain herniation (Chiari II malformation). The advent of intrauterine surgery has provided new opportunities to better address this lifelong debilitating disease. Case Report The patient was a 19-year-old gravida 2 para 1 at 22-6/7 weeks whose fetus was diagnosed with an open neural tube defect and further demonstrated to have ventriculomegaly and hindbrain herniation. Amniocentesis confirmed normal karyotype and the presence of acetylcholinesterase. After an intrauterine procedure, the patient underwent cesarean section at 35-5/7 weeks and delivered a male infant. His spinal incision was well healed at birth without any evidence of cerebrospinal fluid leakage, and his extremities were normal in appearance, range of motion, and movement. The infant also has maintained relatively normal, age-appropriate bowel and bladder function and has no obvious neurologic deficit. Conclusion As the benefit of fetal surgery becomes more widely accepted, quality of care and patient safety must be at the forefront of any institution's effort to offer fetal surgery. Given the current prevalence of spina bifida and the amount of resources required to treat this disease effectively either in utero or postnatally, it is our opinion that the treatment of spina bifida should be regionalized to tertiary referral centers with the interdisciplinary expertise to offer comprehensive treatment for all aspects of the disease and all phases of care for the patients. PMID:24688343

Kahn, Lora; Mbabuike, Nnenna; Valle-Giler, Edison P.; Garces, Juanita; Moore, R. Clifton; Hilaire, Hugo St.; Bui, Cuong J.

2014-01-01

60

Transition into adult healthcare services in Scotland: findings from a study concerning service users at the Scottish Spina Bifida Association  

PubMed Central

Background and Aims Literature on interventions that enable young people with spina bifida and/or hydrocephalus to have smooth transition, into adult healthcare services, stress the need for the process to start early and to include all family members. The study reported here was set to quantify and articulate the experiences of service users who are or due to be going through the transition process in Scotland today. Methods and Results Focus group sessions, in the North of Scotland and in the ‘Central Belt’, captured rich qualitative data. A survey, sent to eligible participants on the Spina Bifida National database, offered complimentary data source. Despite the fact that the number of returned questionnaires was low (n?=?20), data analysis identified a number of core recurring themes. These include issues concerning Communications, Respect, Choice and Control. Findings suggest that there is a significant chasm between the political rhetoric and the reality faced by young people with spina bifida moving to adult healthcare services. Conclusion A possible way to facilitate successful transition of young people is using personal healthcare information as the locus for needed change. More research is needed to ascertain whether a ‘Person-Centred Record’, which is set to empower young people on their transition pathway, is an appropriate transition tool. PMID:25358489

Wynd, Andrew HD; Carachi, Robert

2014-01-01

61

Adolescent Predictors of Emerging Adulthood Milestones in Youth with Spina Bifida*  

PubMed Central

Objective?To examine the predictive utility of demographic (illness status and SES), individual (neurocognitive functioning and intrinsic motivation), and family-based (parental intrusiveness) factors during adolescence on the achievement of emerging adulthood milestones in youth with and without spina bifida (SB).?Methods?Questionnaire and observational data were collected from 14/15-year-old adolescents with SB, typically developing peers, mothers, and teachers. Emerging adulthood milestones (i.e., leaving home, attending college, employment, romantic relationship experience, and number of friendships) were assessed at ages 18/19 years in the full sample and subset of youth who graduated from high school.?Results?Typically, developing youth were more likely to achieve milestones compared to youth with SB in the full sample but not when only high school graduates were compared. Executive function, SES, intrinsic motivation, and parental intrusiveness emerged as significant predictors for particular milestones.?Conclusions?Interventions targeting executive function, intrinsic motivation, and parenting behavior may facilitate achievement of emerging adulthood milestones. PMID:20855288

Zukerman, Jill M.; Devine, Katie A.

2011-01-01

62

Examination of Frontal and Parietal Tectocortical Attention Pathways in Spina Bifida Meningomyelocele Using Probabilistic Diffusion Tractography  

PubMed Central

Abstract Abnormalities of the midbrain tectum are common but variable malformations in spina bifida meningomyelocele (SBM) and have been linked to neuropsychological deficits in attention orienting. The degree to which variations in tectum structure influence white matter (WM) connectivity to cortical regions is unknown. To assess the relationship of tectal structure and connectivity to frontal and parietal cortical regions, probabilistic diffusion tractography was performed on 106 individuals (80 SBM, 26 typically developing [TD]) to isolate anterior versus posterior tectocortical WM pathways. Results showed that those with SBM exhibited significantly reduced tectal volume, along with decreased fractional anisotropy (FA) in posterior but not anterior tectocortical WM pathways when compared with TD individuals. The group with SBM also showed greater within-subject discrepancies between frontal and parietal WM integrity compared with the TD group. Of those with SBM, qualitative classification of tectal beaking based on radiological review was associated with increased axial diffusivity across both anterior and posterior tectocortical pathways, relative to individuals with SBM and a normal appearing tectum. These results support previous volumetric findings of greater impairment to posterior versus anterior brain regions in SBM, and quantifiably relate tectal volume, tectocortical WM integrity, and tectal malformations in this population. PMID:23937233

Juranek, Jenifer; Stuebing, Karla; Cirino, Paul T.; Dennis, Maureen; Fletcher, Jack M.

2013-01-01

63

Physical activity, exercise, and health-related measures of fitness in adults with spina bifida: a review of the literature.  

PubMed

Spina bifida (SB) is the most common birth defect in United States that results in permanent lifelong disability according to the Spina Bifida Association. Advancements in medical care have led to a longer life span and an increase in the risk of secondary conditions, for example, obesity, with age. The need to maintain a healthy and active lifestyle is even stronger in adults with SB than the general population. Our objective was to fill a gap in the literature by highlighting the current state of the literature on health-related measures of fitness, exercise, and physical activity (PA) in adults with SB. PubMed and Ovid were searched for articles by using the terms "spina bifida or myelomeningocele and exercise," published between January 1, 1988 and May 10, 2012. Results of studies showed that adults with SB had an inactive lifestyle, lower aerobic capacity, decreased level of daily PA, higher prevalence of obesity, and lower health-related quality of life compared with reference groups. Therapeutic interventions reduced pain, increased biomechanical efficiency during wheelchair propulsion, and improved PA and balance. Overall, the quality of the evidence on PA, exercise, and health-related measures of fitness is low in SB. Given misdistribution of adipose tissue, short stature, scoliosis, and joint contractures, future research should be conducted to determine the most reliable and low-cost methods of measuring body composition and to establish norms. Other reference standards, for example, aerobic capacity, require further development. Studies are needed to investigate lifestyle interventions that facilitate PA and exercise, and to determine the amount of exercise required to reduce secondary conditions as people with SB age. PMID:24332229

Crytzer, Theresa M; Dicianno, Brad E; Kapoor, Roohi

2013-12-01

64

Parents' psychological adjustment in families of children with Spina Bifida: a meta-analysis  

PubMed Central

Background Spina Bifida (SB) is the second most common birth defect worldwide. Since the chances of survival in children with severe SB-forms have increased, medical care has shifted its emphasis from life-saving interventions to fostering the quality of life for these children and their families. Little is known, however, about the impact of SB on family adjustment. Reviewers have struggled to synthesize the few contradictory studies available. In this systematic review a new attempt was made to summarize the findings by using meta-analysis and by delimiting the scope of review to one concept of family adjustment: Parents' psychological adjustment. The questions addressed were: (a) do parents of children with SB have more psychological distress than controls? (b) do mothers and fathers differ? and (c) which factors correlate with variations in psychological adjustment? Methods PsycInfo, Medline, and reference lists were scanned. Thirty-three relevant studies were identified of which 15 were eligible for meta-analysis. Results SB had a negative medium-large effect on parents' psychological adjustment. The effect was more heterogeneous for mothers than for fathers. In the reviewed studies child factors (age, conduct problems, emotional problems, and mental retardation), parent factors (SES, hope, appraised stress, coping, and parenting competence), family factors (family income, partner relationship, and family climate), and environmental factors (social support) were found to be associated with variations in parents' psychological adjustment. Conclusion Meta-analysis proved to be helpful in organizing studies. Clinical implications indicate a need to be especially alert to psychological suffering in mothers of children with SB. Future research should increase sample sizes through multi-center collaborations. PMID:16120229

Vermaes, Ignace PR; Janssens, Jan MAM; Bosman, Anna MT; Gerris, Jan RM

2005-01-01

65

A description of spina bifida cases and co-occurring malformations, 1976-2011.  

PubMed

Mandatory folic acid fortification in the United States corresponded with a decline in the prevalence of spina bifida (SB). The aim of this study was to describe the epidemiologic characteristics of isolated versus non-isolated SB cases in both pre- and post-fortification periods. SB cases in the Slone Epidemiology Center Birth Defects Study from 1976 to 2011 without chromosomal anomalies and syndromes were included. A maternal interview, conducted within 6 months of delivery, collected information on demographics, reproductive history, diet, and supplement use. Daily folic acid intake in the periconceptional period was calculated using both dietary and supplement information and categorized as low intake (<400?µg/day) or high intake (?400?µg/day). SB cases (n?=?1170) were classified as isolated (80.4%) or non-isolated (19.1%). Non-isolated cases were further divided into subgroups based on accompanying major malformations (midline, renal, genital, heart, laterality). Compared to non-isolated cases, isolated cases were more likely to be white, non-Hispanic and have more than 12 years of education. Cases in the renal, genital, and heart subgroups had the lowest proportions of mothers with a high folic acid intake. The change from pre- to post-fortification was associated with a decrease in the proportion of isolated cases from 83% to 72%, though in both periods isolated cases were more likely to be female and their mothers were more likely to have high folic acid intake. These findings highlight the importance of separating isolated and non-isolated cases in etiologic research of SB. PMID:24357196

Parker, Samantha E; Yazdy, Mahsa M; Mitchell, Allen A; Demmer, Laurie A; Werler, Martha M

2014-02-01

66

Risk of Spina Bifida and Maternal Cigarette, Alcohol, and Coffee Use during the First Month of Pregnancy  

PubMed Central

This study was conducted to assess the association between the risks of spina bifida (SB) in relation to cigarette, alcohol, and caffeine consumption by women during the first month of pregnancy. Between 1988–2012, this multi-center case-control study interviewed mothers of 776 SB cases and 8,756 controls about pregnancy events and exposures. We evaluated cigarette smoking, frequency of alcohol drinking, and caffeine intake during the first lunar month of pregnancy in relation to SB risk. Logistic regression models were used to calculate adjusted odds ratios and 95% confidence intervals. Levels of cigarette smoking (1–9 and ?10/day), alcohol intake (average ?4 drinks/day) and caffeine intake (<1, 1, and ?2 cups/day) were not likely to be associated with increased risk of SB. Further, results were similar among women who ingested less than the recommended amount of folic acid (400 ?g/day). PMID:23917813

Benedum, Corey M.; Yazdy, Mahsa M.; Mitchell, Allen A.; Werler, Martha M.

2013-01-01

67

Left-sided Poland's syndrome in a girl with rare associations like spina bifida and diaphragmatic hernia.  

PubMed

Poland's syndrome is a rare congenital anomaly characterised by partial or complete absence of sternocostal head of pectoralis major muscle and anomalies of ipsilateral hand and digits. Other associated anomalies involving anterior thoracic wall, breast, diaphragm and vertebrae have also been reported in various cases. We report a case of a 10-year-old girl, with features of left-sided Poland's syndrome associated with spina bifida, dextroposition of the heart and left-sided diaphragmatic hernia. These are rare associations of Poland's syndrome. She was investigated with chest X-ray, contrast-enhanced CT of the thorax, ultrasonography of abdomen and echocardiography which helped in arriving at an accurate diagnosis and assessing all the associated abnormalities. PMID:24057335

Sunitha, V C; Narayanan, Sathya; Nair, Pradeep Pankajakshan; Prakash, Manikka Lakshmanan

2013-01-01

68

Executive Functions and Parenting Behaviors in Association With Medical Adherence and Autonomy Among Youth With Spina Bifida  

PubMed Central

Objective?This study was designed to examine whether executive functions and parenting behaviors (acceptance, behavioral control, and psychological control) are associated with medical adherence and autonomy among preadolescents and adolescents with spina bifida (SB).?Methods?Questionnaire and observational data were collected from a sample of 8–15 year olds with SB (N = 140) and their mothers, fathers, and teachers. Youth also completed neuropsychological testing.?Results?Youth with SB demonstrated impairment on measures of executive functions, based on questionnaire and test data. Executive functions (questionnaire data only) and parenting behaviors were associated with medical adherence, but only executive functions (test data only) were associated with medical autonomy. Analyses also suggest that maternal and paternal behavioral control and paternal psychological control moderate relations between executive functions and adherence.?Conclusions?Interventions that target executive functions and parenting behaviors may facilitate positive health care behavior outcomes among youth with SB. PMID:23428651

Holmbeck, Grayson N.

2013-01-01

69

Effect of Preschool Working Memory, Language, and Narrative Abilities on Inferential Comprehension at School-Age in Children with Spina Bifida Myelomeningocele and Typically Developing Children  

PubMed Central

Children with spina bifida myelomeningocele (SBM) are more likely to display a pattern of good-decoding/poor comprehension than their neurologically intact peers. The goals of the current study were to (1) examine the cognitive origins of one of the component skills of comprehension, bridging inferences, from a developmental perspective and (2) to test the effects of those relations on reading comprehension achievement. Data from a sample of children with SBM and a control group (n = 78) who participated in a longitudinal study were taken from age 36-month and 9.5-year time points. A multiple mediation model provided evidence that three preschool cognitive abilities (working memory/inhibitory control, oral comprehension, narrative recall), could partially explain the relation between group and bridging inference skill. A second mediation model supported that each of the 36-month abilities had an indirect effect on reading comprehension through bridging inference skill. Findings contribute to an understanding of both typical and atypical comprehension development, blending theories from the developmental, cognitive, and neuropsychological literature. PMID:23388065

Pike, Meredith; Swank, Paul; Taylor, Heather; Landry, Susan; Barnes, Marcia A.

2014-01-01

70

Cloning, expression, and characterization of recombinant Hev b 3, a Hevea brasiliensis protein associated with latex allergy in patients with spina bifida  

Microsoft Academic Search

Background: Two natural rubber latex proteins, Hev b 1 and Hev b 3, have been described in spina bifida (SB)–associated latex allergy. Objective: The aim of this study was to clone and express Hev b 3 and to obtain the immunologic active and soluble recombinant allergen for diagnosis of SB–associated latex allergy. Methods: A complementary DNA (cDNA) coding for Hev

Birgit Wagner; Monika Krebitz; Dietke Buck; Bodo Niggemann; Hong Yeet Yeang; Kyung-Hwan Han; Otto Scheiner; Heimo Breiteneder

1999-01-01

71

Cotransplantation with specific populations of spina bifida bone marrow stem/progenitor cells enhances urinary bladder regeneration.  

PubMed

Spina bifida (SB) patients afflicted with myelomeningocele typically possess a neurogenic urinary bladder and exhibit varying degrees of bladder dysfunction. Although surgical intervention in the form of enterocystoplasty is the current standard of care in which to remedy the neurogenic bladder, it is still a stop-gap measure and is associated with many complications due to the use of bowel as a source of replacement tissue. Contemporary bladder tissue engineering strategies lack the ability to reform bladder smooth muscle, vasculature, and promote peripheral nerve tissue growth when using autologous populations of cells. Within the context of this study, we demonstrate the role of two specific populations of bone marrow (BM) stem/progenitor cells used in combination with a synthetic elastomeric scaffold that provides a unique and alternative means to current bladder regeneration approaches. In vitro differentiation, gene expression, and proliferation are similar among donor mesenchymal stem cells (MSCs), whereas poly(1,8-octanediol-cocitrate) scaffolds seeded with SB BM MSCs perform analogously to control counterparts with regard to bladder smooth muscle wall formation in vivo. SB CD34(+) hematopoietic stem/progenitor cells cotransplanted with donor-matched MSCs cause a dramatic increase in tissue vascularization as well as an induction of peripheral nerve growth in grafted areas compared with samples not seeded with hematopoietic stem/progenitor cells. Finally, MSC/CD34(+) grafts provided the impetus for rapid urothelium regeneration. Data suggest that autologous BM stem/progenitor cells may be used as alternate, nonpathogenic cell sources for SB patient-specific bladder tissue regeneration in lieu of current enterocystoplasty procedures and have implications for other bladder regenerative therapies. PMID:23431178

Sharma, Arun K; Bury, Matthew I; Fuller, Natalie J; Marks, Andrew J; Kollhoff, David M; Rao, Manoj V; Hota, Partha V; Matoka, Derek J; Edassery, Seby L; Thaker, Hatim; Sarwark, John F; Janicki, Joseph A; Ameer, Guillermo A; Cheng, Earl Y

2013-03-01

72

Copy number variation analysis implicates the cell polarity gene glypican 5 as a human spina bifida candidate gene  

PubMed Central

Neural tube defects (NTDs) are common birth defects of complex etiology. Family and population-based studies have confirmed a genetic component to NTDs. However, despite more than three decades of research, the genes involved in human NTDs remain largely unknown. We tested the hypothesis that rare copy number variants (CNVs), especially de novo germline CNVs, are a significant risk factor for NTDs. We used array-based comparative genomic hybridization (aCGH) to identify rare CNVs in 128 Caucasian and 61 Hispanic patients with non-syndromic lumbar-sacral myelomeningocele. We also performed aCGH analysis on the parents of affected individuals with rare CNVs where parental DNA was available (42 sets). Among the eight de novo CNVs that we identified, three generated copy number changes of entire genes. One large heterozygous deletion removed 27 genes, including PAX3, a known spina bifida-associated gene. A second CNV altered genes (PGPD8, ZC3H6) for which little is known regarding function or expression. A third heterozygous deletion removed GPC5 and part of GPC6, genes encoding glypicans. Glypicans are proteoglycans that modulate the activity of morphogens such as Sonic Hedgehog (SHH) and bone morphogenetic proteins (BMPs), both of which have been implicated in NTDs. Additionally, glypicans function in the planar cell polarity (PCP) pathway, and several PCP genes have been associated with NTDs. Here, we show that GPC5 orthologs are expressed in the neural tube, and that inhibiting their expression in frog and fish embryos results in NTDs. These results implicate GPC5 as a gene required for normal neural tube development. PMID:23223018

Bassuk, Alexander G.; Muthuswamy, Lakshmi B.; Boland, Riley; Smith, Tiffany L.; Hulstrand, Alissa M.; Northrup, Hope; Hakeman, Matthew; Dierdorff, Jason M.; Yung, Christina K.; Long, Abby; Brouillette, Rachel B.; Au, Kit Sing; Gurnett, Christina; Houston, Douglas W.; Cornell, Robert A.; Manak, J. Robert

2013-01-01

73

US Pilot Study of Lumbar to Sacral Nerve Rerouting to Restore Voiding and Bowel Function in Spina Bifida: 3-Year Experience  

PubMed Central

Objective. To report our experience with creating a skin-central nervous system-bladder reflex arc with intradural lumbar to sacral motor root microanastomosis to restore bladder/bowel function in spina bifida patients. Methods. Urinary/bowel changes from baseline to three years were evaluated with questionnaires, voiding diaries, urodynamics (UDS), and renal function studies. Treatment response was defined as CIC ? once/day with stable renal function, voiding efficiency > 50%, and no worsening of motor function. Results. Of 13 subjects (9 female, median age 8 years), 3 voided small amounts at baseline, one voided 200?cc (voiding efficiency 32%), 4/13 reported normal bowels, and 2/13 were continent of stool. Postoperatively, all had transient lower extremity weakness; one developed permanent foot drop. Over three years, renal function remained stable and mean maximum cystometric capacity (MCC) increased (P = 0.0135). In the 10 that returned at 3 years, 7 were treatment responders and 9 had discontinued antimuscarinics, but most still leaked urine. Only 2/8 with baseline neurogenic detrusor overactivity (NDO) still had NDO, all 3 with compliance <10?mL/cm H2O had normalized, 7/10 considered their bowels normal, 5/10 were continent of stool, and 8/10 would undergo the procedure again. Conclusion. Lumbar to sacral nerve rerouting can improve elimination in spina bifida patients. This trial is registered with ClinicalTrials.gov NCT00378664. PMID:24987412

Peters, Kenneth M.; Gilmer, Holly; Feber, Kevin; Girdler, Benjamin J.; Nantau, William; Trock, Gary; Killinger, Kim A.; Boura, Judith A.

2014-01-01

74

Discrepancies in Mother and Child Perceptions of Spina Bifida Medical Responsibilities During the Transition to Adolescence: Associations With Family Conflict and Medical Adherence  

PubMed Central

Objective This study investigated mother–child discrepancies over perceptions of who is responsible for spina bifida (SB) medical tasks in relation to family conflict and medical adherence.?Method?140 youth with SB and their mothers completed questionnaires regarding who is responsible for specific SB medical tasks, family conflict, and medical adherence. An observational measure was also used to assess family conflict.?Results?Although children viewed themselves as more responsible for medical management than mothers did, mother–child discrepancies were not associated with family conflict or medical adherence. Interaction effects revealed that adherence was better when family conflict was low and when parents were responsible for medical tasks.?Conclusions?Parental involvement in SB medical care is essential for optimal medical adherence during adolescence. The presence of family conflict also plays an influential role on SB medical adherence. Future research should evaluate the relations between discrepancies, family conflict, and medical adherence across time. PMID:23843631

Psihogios, Alexandra M.

2013-01-01

75

The assessment of weight status in children and young people attending a spina bifida outpatient clinic: a retrospective medical record review  

PubMed Central

Purpose Children with disabilities are two to three times more likely to become overweight or obese than typically developing children. Children with spina bifida (SB) are at particular risk, yet obesity prevalence and weight management with this population are under-researched. This retrospective chart review explored how weight is assessed and discussed in a children’s SB outpatient clinic. Method Height/weight data were extracted from records of children aged 2–18 with a diagnosis of SB attending an outpatient clinic at least once between June 2009–2011. Body mass index was calculated and classified using Centers for Disease Control and Prevention cut-offs. Notes around weight, diet and physical/sedentary activities were transcribed verbatim and analysed using descriptive thematic analysis. Results Of 180 eligible patients identified, only 63 records had sufficient data to calculate BMI; 15 patients were overweight (23.81%) and 11 obese (17.46%). Weight and physical activity discussions were typically related to function (e.g. mobility, pain). Diet discussions focused on bowel and bladder function and dietary challenges. Conclusions Anthropometrics were infrequently recorded, leaving an incomplete picture of weight status in children with SB and suggesting that weight is not prioritised. Bowel/bladder function was highlighted over other benefits of a healthy body weight, indicating that health promotion opportunities are being missed. Implications for Rehabilitation It is important to assess, categorise and record anthropometric data for children and youth with spina bifida as they may be at particular risk of excess weight. Information around weight categorisation should be discussed openly and non-judgmentally with children and their families. Health promotion opportunities may be missed by focusing solely on symptom management or function. Healthcare professionals should emphasise the broad benefits of healthy eating and physical activity, offering strategies to enable the child to incorporate healthy lifestyle behaviours appropriate to their level of ability. PMID:23510013

Swift, Judy Anne; Yung, Emily; Lyons, Julia; Church, Paige

2013-01-01

76

Can Naturoptics fund Naturopathic Universities to Develop Interlocked Mentoring Relationships with Proposed Universities to Check Sensitivities of Individuals with Spina Bifida, to Environmentally Generated EMF Information about 'Quakes, Hurricanes, etc.?  

NASA Astrophysics Data System (ADS)

Individuals harboring the herpes zoster virus following chicken pox, are susceptible to attacks of shingles. They may indicate peculiar awareness of pricking `pin and needle' sensations and co-symptoms of tinnitus and/or Meuniere's syndrome. RDM used similar symptoms in FL to predict the earthquake ninety miles north of Guantanamo bay in 1998. An astounding burial site in Florida from over six thousand years ago had a teenaged boy with severe spina bifida, with non-Asian genes, who could not have survived without very capable health support. Two youthful individuals likewise afflicted with spina bifida were unearthed from one site at Pompeii, entombed by the eruption of Vesuvius, August 24 and 25, CE 79. We know how to locate sites, active with EMF, which have tornado, hurricane and earthquake associations, and would like to foster joint research also involving Hawaiian and other volcanoes.

McLeod, David M.; Ataide, Italani; McLeod, Roger D.

2006-03-01

77

Spina Bifida Occulta  

MedlinePLUS

... dimple. An ultrasound (only for newborns) or magnetic resonance imaging (MRI) may be used to confirm a problem. This information does not constitute medical advice for any individual. As specific cases may ...

78

Osteoporosis and Spina Bifida  

MedlinePLUS

... to Osteoporosis. What causes Osteoporosis? The normal bone cycle is that old bone breaks down and is ... bone. Osteoporosis creates an imbalance in this rebuilding cycle – old bone breaks down but new bone does ...

79

Development and validation of the Peer Interaction Macro-Coding System Scales (PIMS): A new tool for observational measurement of social competence in youth with spina bifida.  

PubMed

Many children with chronic health conditions encounter enduring difficulties in their peer interactions and friendships. This study aimed to create and validate scales derived from an observational coding system (i.e., Peer Interaction Macro-Coding System, or PIMS) in a sample of children with spina bifida and their peers. Participants were 106 target child-peer dyads who completed a battery of questionnaires and interviews and were videotaped performing 4 interaction tasks, which were then coded across multiple domains of social functioning. Five scales (i.e., Control, Prosocial Skills, Positive Affect, Conflict, and Dyadic Cohesion) were rationally derived based on a review of the literature and a panel of experts. Internal consistency and interrater reliability at the scale level were good to excellent for all 5 scales. Interscale correlations were in the low-to-moderate range for 4 of the scales, although the Dyadic Cohesion Scale was highly correlated with two other scales and was subsequently dropped. Convergent validity and discriminant validity were established by examining the 4 remaining scales in association with comparable questionnaire and interview data. The 4 PIMS scales appear to be reliable and valid measures of social competence and may enhance future multimethod research efforts aimed at learning more about peer interactions and overall social competence. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:24932641

Holbein, Christina E; Zebracki, Kathy; Holmbeck, Grayson N

2014-12-01

80

Functional significance of atypical cortical organization in spina bifida myelomeningocele: relations of cortical thickness and gyrification with IQ and fine motor dexterity.  

PubMed

The cortex in spina bifida myelomeningocele (SBM) is atypically organized, but it is not known how specific features of atypical cortical organization promote or disrupt cognitive and motor function. Relations of deviant cortical thickness and gyrification with IQ and fine motor dexterity were investigated in 64 individuals with SBM and 26 typically developing (TD) individuals, aged 8-28 years. Cortical thickness and 3D local gyrification index (LGI) were quantified from 33 cortical regions per hemisphere using FreeSurfer. Results replicated previous findings, showing regions of higher and lower cortical thickness and LGI in SBM relative to the TD comparison individuals. Cortical thickness and LGI were negatively associated in most cortical regions, though less consistently in the TD group. Whereas cortical thickness and LGI tended to be negatively associated with IQ and fine motor outcomes in regions that were thicker or more gyrified in SBM, associations tended to be positive in regions that were thinner or less gyrified in SBM. The more deviant the levels of cortical thickness and LGI-whether higher or lower relative to the TD group-the more impaired the IQ and fine motor outcomes, suggesting that these cortical atypicalities in SBM are functionally maladaptive, rather than adaptive. PMID:22875857

Treble, Amery; Juranek, Jenifer; Stuebing, Karla K; Dennis, Maureen; Fletcher, Jack M

2013-10-01

81

Peripersonal spatial attention in children with spina bifida: associations between horizontal and vertical line bisection and congenital malformations of the corpus callosum, midbrain, and posterior cortex.  

PubMed

Horizontal and vertical line bisection was studied in 129 children and adolescents between 8 and 19 years of age, one group (n=32) of typically developing controls and one group (n=97) with spina bifida (SBM), a neurodevelopmental disorder associated with dysmorphology of the corpus callosum, posterior cortex, and midbrain. For each participant, structural brain MRIs were analyzed qualitatively to identify beaking of the midbrain tectum and corpus callosum agenesis and hypoplasia and quantitatively by segmentation and volumetric analyses of regional cortical white and gray matter. Each group showed the line length effect, whereby greater estimation errors are made with longer lines. The group with SBM differed from controls in terms of both accuracy and variability of line bisection. Children with SBM showed pseudoneglect, attending more than controls to left hemispace. The extent of rightward bisection bias was unrelated to right posterior brain volumes, although an intact corpus callosum during development moderated and normalized the exaggerated leftward line bisection bias. More children with SBM than controls attended to inferior hemispace. A normal midbrain and greater posterior cortex volume during development moderated and normalized the downward bias. Children with SBM showed more intra-subject variability than controls. Line bisection in children with SBM reflects three deficits: an exaggerated attentional bias to left hemispace, an abnormal attentional bias to inferior hemispace; and a larger zone of subjective uncertainty in bisection judgments. PMID:15893777

Dennis, Maureen; Edelstein, Kim; Frederick, Jon; Copeland, Kim; Francis, David; Blaser, Susan E; Kramer, Larry A; Drake, James M; Brandt, Michael; Hetherington, Ross; Fletcher, Jack M

2005-01-01

82

Functional Significance of Atypical Cortical Organization in Spina Bifida Myelomeningocele: Relations of Cortical Thickness and Gyrification with IQ and Fine Motor Dexterity  

PubMed Central

The cortex in spina bifida myelomeningocele (SBM) is atypically organized, but it is not known how specific features of atypical cortical organization promote or disrupt cognitive and motor function. Relations of deviant cortical thickness and gyrification with IQ and fine motor dexterity were investigated in 64 individuals with SBM and 26 typically developing (TD) individuals, aged 8–28 years. Cortical thickness and 3D local gyrification index (LGI) were quantified from 33 cortical regions per hemisphere using FreeSurfer. Results replicated previous findings, showing regions of higher and lower cortical thickness and LGI in SBM relative to the TD comparison individuals. Cortical thickness and LGI were negatively associated in most cortical regions, though less consistently in the TD group. Whereas cortical thickness and LGI tended to be negatively associated with IQ and fine motor outcomes in regions that were thicker or more gyrified in SBM, associations tended to be positive in regions that were thinner or less gyrified in SBM. The more deviant the levels of cortical thickness and LGI—whether higher or lower relative to the TD group—the more impaired the IQ and fine motor outcomes, suggesting that these cortical atypicalities in SBM are functionally maladaptive, rather than adaptive. PMID:22875857

Treble, Amery; Juranek, Jenifer; Stuebing, Karla K.; Dennis, Maureen; Fletcher, Jack M.

2013-01-01

83

Use of Intravesicular Amikacin Irrigations for the Treatment and Prophylaxis of Urinary Tract Infections in a Patient with Spina Bifida and Neurogenic Bladder: A Case Report  

PubMed Central

This case report describes the use of intravesicular amikacin irrigations to treat and prevent urinary tract infections (UTIs) in a pediatric patient with spina bifida and neurogenic bladder. A 15 year old Hispanic female was admitted for a UTI caused by Enterobacter cloacae and multiple-drug resistant Pseudomonas aeruginosa. A 7 day course of daily intravenous amikacin and ceftazidime was initiated along with twice daily intravesicular amikacin irrigations (15 mg/30 mL) with a dwell time of 2 hours. The patient improved and was discharged on prophylactic Bactrim SS (sulfamethoxazole/trimethoprim) 1 tablet daily and intravesicular amikacin irrigations (15 mg/30 mL) once every other day. Approximately 2 months after discharge, the patient developed another UTI from multidrug resistant Escherichia coli and was treated with a 14 day course of daily intravenous ciprofloxacin accompanied by daily intravesicular amikacin irrigations. Adjunctive therapy with either once daily or twice daily intravesicular amikacin irrigations successfully treated the patient's UTI. However, prophylactic treatment with intravesicular amikacin failed to prevent future UTIs in this patient. PMID:22477833

Huynh, Donna; Morgan, Jill A.

2011-01-01

84

EFFECTIVENESS OF AN UPPER EXTREMITY EXERCISE DEVICE AND TEXT MESSAGE REMINDERS TO EXERCISE IN ADULTS WITH SPINA BIFIDA: A PILOT STUDY  

PubMed Central

Background Obesity, deconditioning, cognitive impairment, and poor exercise tolerance are health issues concerning adults with spina bifida (SB). Our aim is to describe exercise participation and identify motivating tactics and exercise devices that increase participation. Design In a quasi-experimental randomized crossover design, the GameCycle was compared to a Saratoga Silver I arm ergometer. Personalized free or low cost text/voice message reminders to exercise were sent. Methods Nineteen young adults with SB were assigned to either the GameCycle or Saratoga exercise group. Within each group, participants were randomized to receive reminders to exercise, or no reminders, then crossed over to the opposite message group after eight weeks. Before and after a 16 week exercise program we collected anthropometric, metabolic, exercise testing and questionnaire data, and recorded participation. Results Miles traveled by the GameCycle group were significantly higher than the Saratoga exercise groups. No significant differences were found in participation between the message reminder groups. Low participation rates were seen overall. Conclusions Those using the GameCycle traveled more miles. Barriers to exercise participation may have superseded ability to motivate adults with SB to exercise even with electronic reminders. Support from therapists to combat deconditioning and develop coping skills may be needed. PMID:24620701

Crytzer, Theresa M.; Dicianno, Brad E.; Fairman, Andrea D.

2013-01-01

85

Men's Health and Spina Bifida  

MedlinePLUS

... Men's Health Info Sheet here Urologic and Sexual Function Why is bladder control important for sexual activity? ... contact with you. For men with SB, bladder function is inseparable from sexual function. Some of the ...

86

Natural Rubber Latex Allergy in Spina Bifida  

MedlinePLUS

... Rubber Latex? Natural rubber latex (NRL) is a milky substance tapped from the Hevea Brasiliensis (a tropical ... take to prevent developing latex allergy? The best way to prevent developing latex allergy is to avoid ...

87

Tethered Cord in Children with Spina Bifida  

Microsoft Academic Search

Any process that attaches and fixes the spinal cord, inhibiting movement of the cord in the spinal canal, has the potential\\u000a to cause tethered cord syndrome. Motion of the head and trunk changes the length of the spinal canal and the cord must move\\u000a cranially to accommodate increases in length. If the cord is unable to move, it must lengthen

Robin M. Bowman; David G. McLone

88

Obesity among Persons with Spina Bifida  

MedlinePLUS

... exceeds his or her energy needs for bodily functions (metabolism, physical activity, the thermal effect of food, ... like muscle) for the calories it needs to function resulting in weight loss. How is obesity determined? ...

89

Myelomeningocele (open spina bifida) - surgical management.  

PubMed

Myelomeningocele has been recognized since ancient times although written descriptions began not before the 17th century. Among all serious congenital malformations, myelomeningocele is unique that is has a steady and considerable prevalence while being compatible with life. It has a dismal prognosis when left untreated where virtually all die within the first year while aggressive treatment have a profound effect on survival and quality of life. Effective surgical treatment became possible parallel to the treatment of hydrocephalus in the late 1950s. Advent of the shunt systems undoubtedly changed the morbidity and mortality rates due to associated hydrocephalus. Aggressive and effective treatment improved survival rates but also those suffering physical and mental disabilities have increased as well. Ethical and socioeconomic concerns have led to proposal for selective treatment criteria which have raised arguments on medical and ethico-legal rounds. After the swing of the pendulum between early treatment in all affected children and selective treatment of those who fulfilled the criteria for good prognosis, early myelomeningocele repair is practiced widely unless the infant is critically ill.Incidence of myelomeningocele has been decreasing especially in the Western world, partly due to prenatal diagnosis and elective terminations, dietary folate supplementation. Still, it is the most common central nervous system malformation and one of the leading causes of paraplegia, worldwide. Unfortunately, gains in the management of myelomeningocele have been mainly on antenatal diagnosis and prevention while efforts on understanding its cause, mechanisms involved are still tentative. Concerning the surgical management, no revolutionary modification improving outcome has been introduced unlike other fields of neurosurgery.Medical management of a child with myelomeningocele requires a lifelong effort of several disciplines including urology, orthopedics physical and social therapy besides neurosurgery. The initial and probably the most crucial step begin with proper repair of the lesion. The aim of surgery, with its simplest definition should be towards maintaining the medical condition of the newborn. In other words, consequences of an open spinal cord segment with associated malformations have to be avoided with appropriate measures. Comparable to the surgical treatment of any congenital malformation, myelomeningocele repair consist of reversing the failed steps of normal neural tube closure. This requires a thorough understanding of the normal and abnormal embryological sequence of events in formation of the spinal cord. Although the purpose of this chapter is to describe the basic concepts and technique of myelomeningocele repair, contemporary information and progress on epidemiology, and etiology and embryology is presented with discussion of controversial issues regarding the selection process, optimal time for surgery and technical modifications. PMID:21997743

Akalan, N

2011-01-01

90

Depression and Anxiety in Individuals with Spina Bifida  

MedlinePLUS

... there are several different types of depression, including Seasonal Affective Disorder (S.A.D.), Dysthymia, and major depression. The first step in identifying a depressive disorder is to rule out physical causes of behavior or mood change. In people who ...

91

Surgery on Fetus Reduces Complications of Spina Bifida  

MedlinePLUS Videos and Cool Tools

... an opening in the spine. In a new Web video, study author Catherine Y. Spong, M.D., ... medical rehabilitation. For more information, visit the Institute’s Web site at http://www.nichd.nih.gov/ . The ...

92

Spina Bifida / Children of Korean and Vietnam Veterans  

MedlinePLUS

... Vet Centers) War Related Illness & Injury Study Center Homeless Veterans Returning Service Members Rural Veterans Seniors & Aging ... Employment Center Returning Service Members Vocational Rehabilitation & Employment Homeless Veterans Women Veterans Minority Veterans Plain Language Surviving ...

93

Ophthalmologic complications of meningomyelocele: a longitudinal study.  

PubMed Central

Patients with spina bifida have multiple ophthalmologic problems, many of which are preventable. Most of the problems are related to the hydrocephalus, which is caused by the coexisting Arnold-Chiari malformation. When patients are treated for hydrocephalus, and comprehensive eye care is available, 94% of the patients will have 6/12 visual acuity or better. Strabismus is common but it responds well to medical and surgical treatment. Children with spina bifida should have frequent examinations by an ophthalmologist who is familiar with the diagnosis and management of the defects recorded in this study. Images FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 FIGURE 12 PMID:2095031

Biglan, A W

1990-01-01

94

Longitudinal mediators of achievement in mathematics and reading in typical and atypical development.  

PubMed

Longitudinal studies of neurodevelopmental disorders that are diagnosed at or before birth and are associated with specific learning difficulties at school-age provide one method for investigating developmental precursors of later-emerging academic disabilities. Spina bifida myelomeningocele (SBM) is a neurodevelopmental disorder associated with particular problems in mathematics, in contrast to well-developed word reading. Children with SBM (n=30) and typically developing children (n=35) were used to determine whether cognitive abilities measured at 36 and 60 months of age mediated the effect of group on mathematical and reading achievement outcomes at 8.5 and 9.5 years of age. A series of multiple mediator models showed that: visual-spatial working memory at 36 months and phonological awareness at 60 months partially mediated the effect of group on math calculations, phonological awareness partially mediated the effect of group on small addition and subtraction problems on a test of math fluency, and visual-spatial working memory mediated the effect of group on a test of math problem solving. Groups did not differ on word reading, and phonological awareness was the only mediator for reading fluency and reading comprehension. The findings are discussed with reference to theories of mathematical development and disability and with respect to both common and differing cognitive correlates of math and reading. PMID:24269579

Barnes, Marcia A; Raghubar, Kimberly P; English, Lianne; Williams, Jeffrey M; Taylor, Heather; Landry, Susan

2014-03-01

95

Fetal Spina Bifida Repair – Current Trends and Prospects of Intrauterine Neurosurgery  

Microsoft Academic Search

Myelomeningocele is a common dysraphic defect leading to severe impairment throughout the patient’s lifetime. Although surgical closure of this anomaly is usually performed in the early postnatal period, an estimated 330 cases of intrauterine repair have been performed in a few specialized centers worldwide. It was hoped prenatal intervention would improve the prognosis of affected patients, and preliminary findings suggest

M. A. Fichter; U. Dornseifer; J. Henke; K. T. M. Schneider; L. Kovacs; E. Biemer; J. Bruner; N. S. Adzick; M. R. Harrison; N. A. Papadopulos

2008-01-01

96

Arnold Chiari Malformation with Spina Bifida: A Lost Opportunity of Folic Acid Supplementation  

PubMed Central

In Arnold Chiari (kee-AHR-ee) II malformation elongated cerebellar tonsils are displaced inferiorly through the Foramen Magnum into the upper cervical spinal canal. It is a complex anomaly with skull, dura, brain, spine and cord manifestations. Meningomyelocele is seen in all cases. We present a case of type II Arnold Chiari Malformation diagnosed in utero in a pregnant lady .There was no periconceptional folic acid supplementation. As the role of the Methylene Tetra Hydro Folate Reductase gene polymorphism in neural tube defects is becoming evident, a simple opportunity as folic acid supplementation should not be missed. Folate supplementation as fortification of cereal grains will also prevent other conditions like congenital heart defects, urinary tract anomalies, orofacial defects, limb defects and pyloric stenosis.

Sagayaraj, Benjamin M; Barua, Ravi Kumar; Sharma, Nidhi; Ranga, Upasana

2014-01-01

97

Neural Tube Defects, Such as Spina Bifida, on The Decline: CDC  

MedlinePLUS

... folic acid, but not enough women get the B vitamin (*this news item will not be available after ... some women don't get enough of the B vitamin, especially Hispanic women, according to the U.S. Centers ...

98

Radiation treatment of bladder squamous cell carcinoma in a patient with spina bifida: A case report  

PubMed Central

Bladder cancer is the sixth most common cancer in Canada. While most patients present with transitional cell carcinoma, few present with squamous cell carcinoma (SCC). Risk factors for SCC include a history of chronic urinary tract infection, urothelial inflammation and indwelling catheters. We present the management of a patient with locally advanced SCC of the bladder. PMID:22709884

D’Souza, Neil; Morton, Gerard; Chung, Hans T.

2012-01-01

99

45 CFR 84.55 - Procedures relating to health care for handicapped infants.  

Code of Federal Regulations, 2013 CFR

...Association for Retarded Citizens, Down's Syndrome Congress, Spina Bifida Association...or diagnoses, for example, Down's syndrome and spina bifida, and procedures...specified by the ICRC, e.g., Down's syndrome and spina bifida....

2013-10-01

100

AGE-RELATED DIFFERENCES IN EXECUTIVE FUNCTION AMONG CHILDREN WITH SPINA BIFIDA/HYDROCEPHALUS BASED ON PARENT BEHAVIOR RATINGS  

PubMed Central

Previous research has suggested that adolescents with myelomeningocele and shunted hydrocephalus (MMH) have difficulties with aspects of executive functioning and, in turn, with functional independence. There is little research, however, examining patterns of executive functioning across adolescence in this population. The goal of this cross-sectional study was to examine parent ratings of executive function in children with MMH and in typically developing peers across late childhood and adolescence. Parents of 36 individuals with MMH and 35 typically developing peers, ages 10 to 18 years, completed the Behavior Rating Inventory of Executive Function (BRIEF). The BRIEF is organized into eight scales and two primary indices—Metacognition (MCI) and Behavioral Regulation (BRI). As a whole, the children with MMH had significantly higher BRIEF T-scores, as well as a higher prevalence of clinically significant T-scores across subscales, particularly those representing cognitive control. Effects of group, age, and age-by-group interactions on the mean raw scores of the MCI and BRI were examined using regression analyses. There were significant group effects (p < .05) for both the BRI and MCI, with the controls having significantly lower mean ratings than the MMH group. There was also a significant contribution of age-by-group interaction on the BRI (p < .05). Although mean raw scores on the BRI for the MMH group remained stable across ages, mean raw scores in the control group decreased as age increased. Thus, healthy children have age-related improvements in executive control behaviors across adolescence, particularly behavioral control, while children with MMH demonstrate no age-related improvements in parent reported executive behaviors across adolescence. Therefore, children with MMH may continue to require targeted interventions and modifications to address executive dysfunction into young adulthood in order to promote functional independence. PMID:17853154

Tarazi, Reem A.; Zabel, T. Andrew; Mahone, E. Mark

2008-01-01

101

Low temperature mitigates cardia bifida in zebrafish embryos.  

PubMed

The coordinated migration of bilateral cardiomyocytes and the formation of the cardiac cone are essential for heart tube formation. We investigated gene regulatory mechanisms involved in myocardial migration, and regulation of the timing of cardiac cone formation in zebrafish embryos. Through screening of zebrafish treated with ethylnitrosourea, we isolated a mutant with a hypomorphic allele of mil (s1pr2)/edg5, called s1pr2(as10) (as10). Mutant embryos with this allele expressed less mil/edg5 mRNA and exhibited cardia bifida prior to 28 hours post-fertilization. Although the bilateral hearts of the mutants gradually fused together, the resulting formation of two atria and one tightly-packed ventricle failed to support normal blood circulation. Interestingly, cardia bifida of s1pr2(as10) embryos could be rescued and normal circulation could be restored by incubating the embryos at low temperature (22.5°C). Rescue was also observed in gata5 and bon cardia bifida morphants raised at 22.5 °C. The use of DNA microarrays, digital gene expression analyses, loss-of-function, as well as mRNA and protein rescue experiments, revealed that low temperature mitigates cardia bifida by regulating the expression of genes encoding components of the extracellular matrix (fibronectin 1, tenascin-c, tenascin-w). Furthermore, the addition of N-acetyl cysteine (NAC), a reactive oxygen species (ROS) scavenger, significantly decreased the effect of low temperature on mitigating cardia bifida in s1pr2(as10) embryos. Our study reveals that temperature coordinates the development of the heart tube and somitogenesis, and that extracellular matrix genes (fibronectin 1, tenascin-c and tenascin-w) are involved. PMID:23922799

Lin, Che-Yi; Huang, Cheng-Chen; Wang, Wen-Der; Hsiao, Chung-Der; Cheng, Ching-Feng; Wu, Yi-Ting; Lu, Yu-Fen; Hwang, Sheng-Ping L

2013-01-01

102

Spectral analysis of erector spinae EMG during intermittent isometric fatiguing exercise  

Microsoft Academic Search

The applicability of EMG spectral analysis in the study of muscular fatigue of the erector spinae muscle was investigated. At three locations (L1, L2, L5) of the erector spinae muscle, representing different functional parts, EMG was sampled during fatiguing intermittent isometric extension of the trunk. The multifidus muscle (L5) appeared to show the most consistent changes of the EMG power

J. H. VAN DIEEN; H. M. TOUSSAINT; C. THISSEN; A. VAN DE VEN

1993-01-01

103

75 FR 9276 - Proposed Information Collection (Application for CHAMPVA Benefits); Comment Request  

Federal Register 2010, 2011, 2012, 2013, 2014

...Vietnam veterans born with spina bifida and certain other covered birth defects. DATES: Written comments and recommendations on the...reimbursement of expenses related to spina bifida and certain covered birth defects. Affected Public: Individuals or households....

2010-03-01

104

Yale Pediatrics A PRACTICE OF THE YALE MEDICAL GROUP PEDIATRIC SPECIALTY NEW PATIENT FORM Date  

E-print Network

-785-3365 Rheumatology 203-737-7635 Bone Clinic 203-737-7635 Infectious Diseases 203-785-6961 Spina Bifida 203/Behavioral Pediatrics Rheumatology Endocrinology Spina Bifida GI Thyroid Center MDA/Neuromuscular Type 2 Diabetes

105

Block the function of nonmuscle myosin II by blebbistatin induces zebrafish embryo cardia bifida.  

PubMed

Nonmuscle myosin II (NM II) is the name given to the multi-subunit protein product of three genes encoding different nonmuscle myosin heavy chains including NM II-A, NM II-B, and NM II-C. Blebbistatin is a small molecule that has been shown to be a relatively specific inhibitor of NM II. Blocking the function of NM II by blebbistatin induces zebrafish embryo cardia bifida at a dose-dependent manner. In situ hybridization analysis with ventricular marker ventricular myosin heavy chain (vmhc) and atrial marker atrial myosin heavy chain (amhc) showed each of the heart contained both distinct atria and ventricle. However, the cardia bifida embryos had highly variable distance between two separate ventricles. We also provided evidence that time window from 12 to 20 h post fertilization (hpf) is necessary and sufficient for cardia bifida formation caused by blebbistatin treatment. Expression of spinster homolog 2 (spns2) was decreased in blebbistatin-treated embryos, suggesting the cardia bifida phenotype caused by NM II inhibition was relevant to precardiac mesoderm migration defects. Through in situ hybridization analysis, we showed that foxa1 was expressed in endoderm of blebbistatin-treated embryos at 24-hpf stage, suggesting the endoderm formation is normal in cardia bifida embryos caused by blebbistatin treatment. In addition, we demonstrated that blebbistatin treatment resulted in morphology alteration of zebrafish cardiomyocytes in vivo and neonatal mouse cardiomyocytes in vitro. PMID:25403653

Wang, Xueqian; Chong, Mei; Wang, Xin; Wang, Hongkui; Zhang, Jie; Xu, Hui; Zhang, Jingjing; Liu, Dong

2014-11-18

106

Quantification of erector spinae muscle fatigue during prolonged, dynamic lifting tasks  

Microsoft Academic Search

A method was developed to quantify erector spinae fatigue resulting from repetitive dynamic lifting in the sagittal plane. This method was tested with the data from eight male subjects lifting inertial loads of 19 kg and 17 kg during sessions of 20 min and 2 h, respectively. Surface EMG electrodes were applied over sites representing the bilateral lumbar and thoracic

J. R. Potvin; R. W. Norman

1993-01-01

107

Comparison of the Electromyographic Activation Level and Unilateral Selectivity of Erector Spinae during Different Selected Movements  

ERIC Educational Resources Information Center

For patients with scoliosis, core stabilization exercises may be beneficial in improving muscle strength and trunk dynamic control. However, few studies have examined whether the erector spinae (ES) activation status during unilateral spinal extensor strengthening meets the guideline for patients with spinal scoliosis. To determine ES activation…

Guo, Lan-Yuen; Wang, Yu-Lin; Huang, Yu-Han; Yang, Chich-Haung; Hou, Yi-You; Harn, Hans I-Chen; You, Yu-Lin

2012-01-01

108

Relationship Between Erectores Spinae Voltage and Back-Lift Strength for Isometric, Concentric, and Eccentric Contractions  

ERIC Educational Resources Information Center

This study determined the maximal mean values for concentric and eccentric back-lift strength as well as isometric, and examined and compared the relationships between the mean peak voltage of the erectores spinae muscle(s) and maximal force exerted for the three types of muscle contractions. (RC)

Ashton, T. Edwin J.; Singh, Mohan

1975-01-01

109

The ethnobotany of Christ's Thorn Jujube (Ziziphus spina-christi) in Israel  

Microsoft Academic Search

This article surveys the ethnobotany of Ziziphus spina-christi (L.) Desf. in the Middle East from various aspects: historical, religious, philological, literary, linguistic, as well as pharmacological, among Muslims, Jews, and Christians. It is suggested that this is the only tree species considered \\

Amots Dafni; Shay Levy; Efraim Lev

2005-01-01

110

The ethnobotany of Christ's Thorn Jujube (Ziziphus spina-christi) in Israel  

PubMed Central

This article surveys the ethnobotany of Ziziphus spina-christi (L.) Desf. in the Middle East from various aspects: historical, religious, philological, literary, linguistic, as well as pharmacological, among Muslims, Jews, and Christians. It is suggested that this is the only tree species considered "holy" by Muslims (all the individuals of the species are sanctified by religion) in addition to its status as "sacred tree " (particular trees which are venerated due to historical or magical events related to them, regardless of their botanical identity) in the Middle East. It has also a special status as "blessed tree" among the Druze. PMID:16270941

Dafni, Amots; Levy, Shay; Lev, Efraim

2005-01-01

111

MEMS test structure for measuring thermal conductivity of thin films L. La Spina, N. Nenadovi*, A. W. van Herwaarden**,  

E-print Network

MEMS test structure for measuring thermal conductivity of thin films L. La Spina, N. Nenadovi*, A procedure is presented with which the lateral thermal conductivity of thin films can be easily. Experimental examples are given for the determination of the lateral thermal conductivity of aluminium (Al

Technische Universiteit Delft

112

Evaluation of the antidiarrhoeal effects of Zizyphus spina-christi stem bark in rats.  

PubMed

The antidiarrhoeal effects of the methanol extract of Zizyphus spina-christi stem bark were evaluated in laboratory rodents. Studies on castor oil induced diarrhoea, intraluminal fluid accumulation, and gastrointestinal transit time were carried out. Results obtained revealed that the extract caused a dose dependent protection of rats against castor oil induced diarrhoea, decreased the intraluminal fluid accumulation and gastrointestinal transit. The intraperitoneal and oral LD(50) values were found to be 346+/-5.6 and 1200+/-41.2 mg/kg in mice. Preliminary phytochemical screening revealed the presence of glycosides, resins, saponins, and tannins. It is suggested that the extract may contain biologically active components that may be useful against diarrhoea, thereby justifying its use in ethnomedical practice as an antidiarrhoeal agent. PMID:12826300

Adzu, B; Amos, S; Amizan, M B; Gamaniel, K

2003-07-01

113

A Massive Tuberculosis Abscess at the Erector Spinae Muscles and Subcutaneous Tissues in a Young Man  

PubMed Central

Tuberculosis (TB) is a chronic granulomatous infection which can present in an atypical form. Isolated muscle involvement is very rare. We report a 25-year-old man who presented with a massive cystic swelling on the right side of his back, extending from the lower thoracic to the gluteal region. He had a history of contact with a friend who was suspected of having TB. Magnetic resonance imaging (MRI) showed that the origin of the cyst was from the erector spinae muscles. The result of a fluid aspirate showed acid fast bacilli. The swelling disappeared after treatment with anti-tuberculous medications. Muscular involvement in TB is very rare. In our patient, the reports of an ultrasound and MRI confirmed isolated muscle and subcutaneous involvement without bony lesions. This case is reported to increase physician awareness regarding soft tissue TB. Although it is rare, similar cases may be seen in the future. PMID:24273676

Elshafie, Kawther T.; Al-Hinai, Mustafa M.; Al-Habsi, Hamdan A.; Al-Hattali, Mohammed S.; Hassan, Osama; Al-Sukaiti, Rashid

2013-01-01

114

Presentation and Management of Hydromyelia in Children with Chiari Type-II Malformation  

Microsoft Academic Search

Hydromyelia in patients with myelomeningocele and Chiari-II malformation is a relatively frequent finding on MRI studies. However, not all children develop symptoms from the hydromyelia that requires treatment. Furthermore, treatment of hydromyelia in spina bifida patients is rather complex due to the associated malformations. The authors retrospectively analyzed 231 MRI studies carried out on spina bifida patients who presented neurological

Frank La Marca; Martin Herman; John A. Grant; David G. McLone

1997-01-01

115

Pathophysiology of Hydrocephalus  

Microsoft Academic Search

The three major clinical manifestations of spina bifida (hydrocephalus, paraplegia and urinary and bowel incontinence) are\\u000a easily observable and have been described since ancient times, though they were not described in relationship to spina bifida\\u000a until the seventeenth century [1].

Giuseppe Cinalli; Pietro Spennato; Maria Consiglio Buonocore; Emilio Cianciulli; Matthieu Vinchon; Spyros Sgouros

116

Longitudinal Multistage Testing  

ERIC Educational Resources Information Center

This article introduces longitudinal multistage testing (lMST), a special form of multistage testing (MST), as a method for adaptive testing in longitudinal large-scale studies. In lMST designs, test forms of different difficulty levels are used, whereas the values on a pretest determine the routing to these test forms. Since lMST allows for…

Pohl, Steffi

2013-01-01

117

Digital Longitudinal Tomosynthesis  

Microsoft Academic Search

The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed \\

Daniel Steven Rimkus

1985-01-01

118

Longitudinal Magnification Drawing Mistake  

NASA Astrophysics Data System (ADS)

Lateral magnification in image formation by positive lenses, mirrors, and dioptrics is usually appropriately developed in most optics textbooks.1-9 However, the image of a three-dimensional object occupies a three-dimensional region of space. The optical system affects both the transverse and the longitudinal dimensions of the object and, in general, does it in different ways. The magnification in the direction of the optical axis (the longitudinal magnification) is seldom treated. In several texts, the concept of longitudinal magnification is not even considered. Symmetrical objects (such as arrows) are used and their images appear laterally inverted. It is not shown how a longitudinally nonsymmetric object is imaged. One of the few books where this subject is well treated is in the textbook by Hecht.10 We have repeatedly verified in our classes that there is some confusion related to this subject. Students tend to believe that the image is longitudinally symmetric with respect to the lens optic center. Some prestigious texts commit the same mistake. In addition, a very nice optics book,11 a catalogue of optical hardware,12 a worldwide scientific magazine,13 a paper in an optics journal,14 and a Spanish encyclopedia,15 for example, have also been found to contain this error in drawing the image of a three-dimensional object formed by a positive lens. In this paper we suggest that the teaching of longitudinal magnification should be done with some care and we include a figure showing a properly drawn image.

Rabal, Héctor; Cap, Nelly; Trivi, Marcelo

2004-01-01

119

Formulation and evaluation of antihyperglycemic leaf extracts of Zizyphus spina-christi (L.) Willd.  

PubMed

This study deals with the formulation of antihyperglycemic leaf extracts of Zizyphus spina-christi (L.) Willd. A bioactivity guided fractionation of different leaf extracts [defatted ethanol 70% (a), butanol (b), ethanol 70% (c), ethyl acetate (d) and petroleum ether (e) extracts] revealed that extract (c) possessed the highest antihyperglycemic activity followed by (b) and (a). HPLC was adopted for standardization of the extract (c) based on evaluation of the major saponin christinin-A which was used as marker. The detection limit was 9.45 mg/ml for Christinin-A. Extracts (a), (b) and (c) were separately formulated in soft (S) and hard (H) gelatin capsules. Two different formulations (F1 and F2) were tried using different excipients suitable for oral drug delivery. Formula 1, used for soft gelatin capsules [(F1) Sa, Sb, Sc] Formula 2, used for hard gelatin capsules [(F2) - Ha, Hb, Hc]. The recovery rates of the samples of saponin were in the range 99.43-101.86% at 200, 800 microg/ml and 1200 microg/ml. Saponin release rates from different formulae were carried out using dissolution tester USP XXIV. The highest release was obtained from formulation Sc. The release of the extracts followed diffusion mechanism. The selected formula Sc exhibited highest anti-diabetic activity (P < 0.01) on acute and long-term administration and highest saponin release. This formula (Sc) contained poly-oxyethylene (20) cetyl ether (BC-20TX), PEG 400, PEG 6000, purified water, meglyol 810, ascorbic acid and 200 mg of extract (c). PMID:19320283

Nesseem, D I; Michel, C G; Sleem, A A; El-Alfy, T S

2009-02-01

120

Effects of low-frequency electrical stimulation on cumulative fatigue and muscle tone of the erector spinae  

PubMed Central

[Purpose] The aim of this study was to determine the effect of low-frequency electrical stimulation on fatigue recovery of the erector spinae with cumulative fatigue induced by repeated lifting and lowering work. [Subjects] Thirty-two healthy men volunteered to participate in this study and they were randomly divided into three groups: a MC group of 12 persons who underwent microcurrent, a TENS group of 10 persons who underwent Transcutaneous electrical nerve stimulation, and a control group of 10 persons who only rested. [Methods] Cumulative fatigue was induced and then, EMG, muscle tone, CK and LDH serum levels of the erector spinae were measured. Each group then underwent the assigned intervention and was re-measured. To analyze the differences in fatigue between before and after the intervention, the paired t-test was conducted, while groups were compared using analysis of covariance with a control group. [Results] The MC groups showed a significant reduction in muscle fatigue and decreased muscle tone when compared to the control group. However, no significant differences were found between the TENS and control groups. [Conclusion] These results suggest that microcurrent stimulation was effective for recovery from cumulative muscle fatigue while TENS had no effect. PMID:25642049

Kang, Da-Haeng; Jeon, Jae-Keun; Lee, Joon-Hee

2015-01-01

121

Longitudinal discharge laser baffles  

DOEpatents

The IR baffles placed between the window and the electrode of a longitudinal discharge laser improve laser performance by intercepting off-axis IR radiation from the laser and in doing so reduce window heating and subsequent optical distortion of the laser beam.

Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

1994-01-01

122

Longitudinal discharge laser electrodes  

DOEpatents

The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window.

Warner, Bruce E. (Livermore, CA); Miller, John L. (Dublin, CA); Ault, Earl R. (Dublin, CA)

1994-01-01

123

Nonlinear Longitudinal KTN Modulator.  

PubMed

The longitudinal quadratic electrooptic effect in the solid solution material KTa(x)Nb(1-x)O(3) (KTN) has been investigated. It is shown that the effect is optimum for the [110] direction. For this direction the effective longitudinal electrooptic coefficient for a stress-free crystal is given by g' = |g(12) - g(11) + g(44)|. With this effect half-wave voltages as low as 100 V can be achieved in thin plates (<200 microm). It is shown that the paraelectric and ferroelectric electrooptic effects in these plates can be described by using the Devonshire thermodynamic formalism. In particular the temperature variation of the half-wave voltage is derived and comparison with the experimentally observed variation shows this to be anomalously large. Expressions are also derived for the transfer function of a quadratic modulator in both the biased and unbiased states. These expressions are in good agreement with the experimental results. Finally, the limitations and applications of the longitudinal KTN modulator are described. It is concluded that power dissipation problems limit the operation of longitudinal KTN devices to frequencies less than 100 kHz. PMID:20134890

Fox, A J

1975-02-01

124

WISCONSIN LONGITUDINAL STUDY (WLS)  

EPA Science Inventory

The Wisconsin Longitudinal Study (WLS) is a long-term study of a random sample of 10,317 men and women who graduated from Wisconsin high schools in 1957. The WLS provides an opportunity to study of the life course, intergenerational transfers and relationships, family functioning...

125

Longitudinal discharge laser electrodes  

DOEpatents

The improved longitudinal discharge laser electrode with IR baffle includes an electrode made up of washers spaced along the laser axis in order to form inter-washer spaces for hollow cathode discharge to take place and for IR radiation to be trapped. Additional IR baffles can be placed between the electrode ann the window. 2 figs.

Warner, B.E.; Miller, J.L.; Ault, E.R.

1994-08-23

126

Bellows With Longitudinal Beams  

NASA Technical Reports Server (NTRS)

Bellows assembled using two longitudinal side seams allow seam joints to be placed in axial directions of bellows. Design of particular importance in difficult situations where frequent assembly or repair required or in limited-access areas not desirable to disassemble total unit to replace one-piece bellows.

Garvin, W.

1984-01-01

127

Experimental Demonstration of Longitudinal Magnification  

ERIC Educational Resources Information Center

We describe an experiment which enables the observation of longitudinal magnification for the real image of a three-dimensional (3D) object formed by a converging lens. The experiment also shows the absence of longitudinal inversion. Possible reasons for misconceptions with respect to real images and longitudinal inversions are discussed and a…

Razpet, Nada; Susman, Katarina; Cepic, Mojca

2009-01-01

128

Longitudinally Graded Optical Fibers  

NASA Astrophysics Data System (ADS)

Described herein, for the first time to the best of our knowledge, are optical fibers possessing significant compositional gradations along their length due to longitudinal control of the core glass composition. More specifically, MCVD-derived germanosilicate fibers were fabricated that exhibited a gradient of up to about 0.55 weight percent GeO2 per meter. These gradients are about 1900 times greater than previously reported for fibers possessing longitudinal changes in composition. The refractive index difference is shown to change by about 0.001, representing a numerical aperture change of about 10%, over a fiber length of less than 20 m. The lowest attenuation measured from the present longitudinally-graded fiber (LGF) was 82 dB/km at a wavelength of 1550 nm, though this is shown to result from extrinsic process-induced factors and could be reduced with further optimization. The stimulated Brillouin scattering (SBS) spectrum from the LGF exhibited a 4.4 dB increase in the spectral width, and thus reduction in Brillouin gain, relative to a standard commercial single mode fiber, over a fiber length of only 17 m. Fibers with longitudinally uniform (i.e., not gradient) refractive index profiles but differing chemical compositions among various core layers were also fabricated to determine acoustic effects of the core slug method. The refractive index of the resulting preform varies by about +/- 0.00013 from the average. Upon core drilling, it was found that the core slugs had been drilled off-center from the parent preform, resulting in semi-circular core cross sections that were unable to guide light. As a result, optical analysis could not be conducted. Chemical composition data was obtained, however, and is described herein. A third fiber produced was actively doped with ytterbium (Yb3 ) and fabricated similarly to the previous fibers. The preforms were doped via the solution doping method with a solution of 0.015 M Yb 3 derived from ytterbium chloride hexahydrate and 0.30 M Al 3 derived from aluminum chloride hexahydrate. The doped preform was engineered to have two core layers of differing chemical composition, resulting in both a gradient refractive index profile as well as a gradient acoustic profile. While exhibiting higher loss than the original LGF, the Yb 3-doped fiber showed slightly better SBS suppression with preliminary calculations showing at least 6 dB reduction in Brillouin gain. Lastly, reported here is a straight-forward and flexible method to fabricate silica optical fibers of circular cladding cross-section and rectilinear cores whose aspect ratio and refractive index profile changes with position along the fiber in a deterministic way. Specifically, a modification to the process developed to produce longitudinally-graded optical fibers, was employed. Herein reported are MCVD-derived germanosilicate fibers with rectangular cores where the aspect ratio changes by nearly 200 % and the average refractive index changed by about 5 %. Fiber losses were measured to be about 50 dB/km. Such rectangular core fibers are useful for a variety of telecommunication and biomedical applications and the dimensional and optical chirp provides a deterministic way to control further the modal properties of the fiber. Possible applications of longitudinally graded optical fibers and future improvements are also discussed. The methods employed are very straight-forward and technically simple, providing for a wide variety of longitudinal refractive index and acoustic velocity profiles, as well as core shapes, that could be especially valuable for SBS suppression in high energy laser systems. Next generation analogs, with longitudinally-graded compositional profiles that are very reasonable to fabricate, are shown computationally to be more effective at suppressing SBS than present alternatives, such as externally-applied temperature or strain gradients.

Evert, Alexander George

129

Muon cooling: longitudinal compression.  

PubMed

A 10??MeV/c positive muon beam was stopped in helium gas of a few mbar in a magnetic field of 5 T. The muon "swarm" has been efficiently compressed from a length of 16 cm down to a few mm along the magnetic field axis (longitudinal compression) using electrostatic fields. The simulation reproduces the low energy interactions of slow muons in helium gas. Phase space compression occurs on the order of microseconds, compatible with the muon lifetime of 2???s. This paves the way for the preparation of a high-quality low-energy muon beam, with an increase in phase space density relative to a standard surface muon beam of 10^{7}. The achievable phase space compression by using only the longitudinal stage presented here is of the order of 10^{4}. PMID:24949772

Bao, Yu; Antognini, Aldo; Bertl, Wilhelm; Hildebrandt, Malte; Khaw, Kim Siang; Kirch, Klaus; Papa, Angela; Petitjean, Claude; Piegsa, Florian M; Ritt, Stefan; Sedlak, Kamil; Stoykov, Alexey; Taqqu, David

2014-06-01

130

45 CFR 1308.12 - Eligibility criteria: Orthopedic impairment.  

Code of Federal Regulations, 2014 CFR

...affect a child's learning. An orthopedic impairment involves muscles, bones, or joints and is characterized by impaired ability...includes, but is not limited to, spina bifida, cerebral palsy, loss of or deformed limbs, contractures caused by burns,...

2014-10-01

131

Folic acid and birth defect prevention  

MedlinePLUS

Prevention of birth defects with folic acid (folate) ... There is good evidence that taking folic acid before and during pregnancy can reduce the risk of certain birth defects ( spina bifida , anencephaly , and some heart defects). Experts recommend taking 400 ...

132

Preparing for Multiple Births  

MedlinePLUS

... throughout the pregnancy will decrease the risk of neural tube defects (such as spina bifida ). Another dietary ... best reassurance is knowing that you have a network of support around you: capable doctors, a caring ...

133

77 FR 58395 - Proposed Data Collections Submitted for Public Comment and Recommendations  

Federal Register 2010, 2011, 2012, 2013, 2014

...several better-known childhood conditions, including Down syndrome and spina bifida. The birth prevalence of congenital...g., increased parental anxiety, ``fragile child syndrome''). CDC is requesting OMB approval for one...

2012-09-20

134

78 FR 4411 - Agency Forms Undergoing Paperwork Reduction Act Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...several better-known childhood conditions, including Down Syndrome and Spina Bifida. The birth prevalence of congenital...g., increased parental anxiety, ``fragile child syndrome''). CDC is requesting OMB approval for one...

2013-01-22

135

38 CFR 17.901 - Provision of health care.  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Provision of health care. 17.901 Section 17.901...DEPARTMENT OF VETERANS AFFAIRS MEDICAL Health Care Benefits for Certain Children...Birth Defects § 17.901 Provision of health care. (a) Spina bifida....

2012-07-01

136

38 CFR 17.901 - Provision of health care.  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Provision of health care. 17.901 Section 17.901...DEPARTMENT OF VETERANS AFFAIRS MEDICAL Health Care Benefits for Certain Children...Birth Defects § 17.901 Provision of health care. (a) Spina bifida....

2011-07-01

137

38 CFR 17.901 - Provision of health care.  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Provision of health care. 17.901 Section 17.901...DEPARTMENT OF VETERANS AFFAIRS MEDICAL Health Care Benefits for Certain Children...Birth Defects § 17.901 Provision of health care. (a) Spina bifida....

2014-07-01

138

38 CFR 17.901 - Provision of health care.  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Provision of health care. 17.901 Section 17.901...DEPARTMENT OF VETERANS AFFAIRS MEDICAL Health Care Benefits for Certain Children...Birth Defects § 17.901 Provision of health care. (a) Spina bifida....

2013-07-01

139

Birth Defects: What They Are and How They Happen  

MedlinePLUS

... include heart defects , cleft lip and cleft palate , Down syndrome and spina bifida . Find out how to prevent ... the choroid plexus. These cysts are made of blood vessels and tissue. They do not cause intellectual disabilities ...

140

Scoliosis  

MedlinePLUS

... problem that affects the muscles. Problems can include cerebral palsy , muscular dystrophy , spina bifida, and polio . ... They may have another serious disorder such as cerebral palsy or muscular dystrophy, so their goals are much ...

141

Wheelchairs  

MedlinePLUS

... Others have disabilities due to muscular dystrophy or cerebral palsy . In some cases, kids have wheelchairs but don' ... Needs Spina Bifida In the Band: Jens' Story Cerebral Palsy Steven's Story: Power Player Going to a Physical ...

142

Yale Pediatrics A PRACTICE OF THE YALE MEDICAL GROUP PEDIATRIC SPECIALTY NEW PATIENT FORM Date  

E-print Network

-737-7635 Develop. & Behavioral 203-737-7635 Hepatology 203-785-3365 Rheumatology 203-737-7635 Endocrinology Rheumatology Spina Bifida Patientor referring officecalls 203-785-4081 #1 to schedule appointment Appointment

143

Spectral analysis of erector spinae muscle surface electromyography as an index of exercise performance in maximal treadmill running.  

PubMed

Thirteen male athletes (mean 20.7 years) participated in the present study which investigated the relationship between mean power frequency (MPF) and exercise intensity determined from gas analysis during maximal treadmill running. All subjects performed two consecutive ramp exercise tests on the treadmill. Myoelectric signals from surface electrodes on the erector spinae muscles were digitized and MPF was calculated every ten seconds. Gas exchange data was collected using an automated breath-by-breath system, from which the anaerobic threshold (AT), respiratory gas exchange ratio (R = VCO2/VO2), and %VO2 = VO2/VO2max were obtained. During loading, MPF showed a steady decrease, followed by a sudden fall to a base level in both tests. After loading, MPF recovered within 30 seconds in all subjects. The test-retest reliability coefficient of MPF and R at the point of sudden fall in MPF were 0.757 (p = 0.0018), and 0.808 (p = 0.0004). These findings suggest that a sudden fall and a base level of MPF indicate local muscle fatigue, and the spectral analysis of trunk muscle surface EMG provides a reliable index of exercise performance in maximal treadmill running. PMID:10740977

Nagamachi, A; Ikata, T; Katoh, S; Morita, T

2000-02-01

144

Longitudinally extensive myelopathy in children.  

PubMed

When children present with acute myelopathy manifested by sensory, motor, or bowel and bladder symptoms, MRI of the neuraxis with contrast agent is the most important imaging study to obtain. Although occasionally normal, MRI often demonstrates signal abnormality within the spinal cord. Classically, longitudinally extensive transverse myelitis (?3 vertebral bodies in length) has been described with neuromyelitis optica (NMO), but alternative diagnoses should be considered. This pictorial essay reviews the differential diagnoses that may present with longitudinally extensive spinal cord signal abnormalities. Multiple inflammatory, infectious, vascular, metabolic and neurodegenerative etiologies can present with a myelopathy. Thus, radiologists can assist in the diagnosis by familiarizing themselves with the spectrum of diseases in childhood that result in longitudinally extensive signal abnormalities in the absence of trauma. PMID:25636706

Sorte, Danielle Eckart; Poretti, Andrea; Newsome, Scott D; Boltshauser, Eugen; Huisman, Thierry A G M; Izbudak, Izlem

2015-02-01

145

Longitudinal health effects of disasters  

Microsoft Academic Search

Background: We carry out prospective, longitudinal studies on the possible health effects of two disasters in the Netherlands: the explosion of fireworks depot in a residential area (Enschede) and a fire in discotheque in Volendam. Learning from the chaotic aftermath previous disasters, the Dutch government attempts to prevent longterm public health damage by means of a pro-active public health response;

C. J. Yzermans

2004-01-01

146

Longitudinal and Transverse Wave Motion  

NSDL National Science Digital Library

Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) at a wave speed which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves.

147

Regression analysis with longitudinal measurements  

E-print Network

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.3.Bayesian regression . . . . . . . . . . . . . . . . . . . . . . 9 A. Regression for continuous response . . . . . . . . . . . 9 B. Regression for binary response . . . . . . . . . . . . . 10 2.4.Parametric regression analysis on cardiotoxic... . . . . . . . . . . . . . . . . . . 49 B. Nonparametric regression . . . . . . . . . . . . . . . . 51 5.4.Model diagnostics . . . . . . . . . . . . . . . . . . . . . . . 53 5.5.Simulation study . . . . . . . . . . . . . . . . . . . . . . . 55 5.6.Longitudinal study of cardiotoxicity...

Ryu, Duchwan

2005-08-29

148

Longitudinal Studies of Spelling Development.  

ERIC Educational Resources Information Center

Noting that proposed models of literacy development suggest that reading and writing mutually influence and grow from each other, this paper summarizes aspects of stage theories of literacy development and an integrative model, and considers how the model fared in empirical longitudinal tests. The paper begins with a summary of the modal aspects…

Ellis, Nick

149

Longitudinal and Transverse Wave Motion  

NSDL National Science Digital Library

This group of animations with accompanying text illustrates the difference between the two primary types of mechanical waves: longitudinal and transverse. It is part of a larger collection of resources on wave motion, acoustics, and sound authored by Dan Russell of Kettering University.

Russell, Dan

2006-05-18

150

Panel - Generic Longitudinal Business Process Model  

E-print Network

This presentation described a model for the processes involved in a longitudinal study. The model was developed at a symposium-style workshop held at Dagstuhl in September of 2011 (http://www.dagstuhl.de/11382). The Generic Longitudinal Business...

Barkow, Ingo; Block, William C.; Greenfield, Jay; Hebing, Marcel; Hoyle, Larry; Thomas, Wendy

2013-04-03

151

Memory Strategy Development: Lessons from Longitudinal Research.  

ERIC Educational Resources Information Center

Reviews development of rehearsal and organizational strategies based on cross-sectional and longitudinal research, focusing on the Munich Longitudinal Study. Found that longitudinal data reveal greater individual variability in strategy acquisition, suggesting that canonical development patterns inferred from cross-sectional studies obfuscate…

Schneider, Wolfgang; Sodian, Beate

1997-01-01

152

Longitudinal evidence on financial expectations in Albania  

E-print Network

EA 4272 Longitudinal evidence on financial expectations in Albania: Do remittances matter? Laetitia-14Dec2010 #12;Longitudinal evidence on financial expectations in Albania: Do remittances matter of remittances on financial expectations in Albania using longitudinal data covering the period 2002

Paris-Sud XI, Université de

153

The Importance of Longitudinal Studies  

NASA Astrophysics Data System (ADS)

It has been eight years since the AAS Council unanimously endorsed the document, known as "Equity Now: The Pasadena Recommendations for Gender Equality in Astronomy," in January 2005. This document was the main product of the conference entitled “Women in Astronomy II: Ten Years After” (WIA II), held in June 2003 in Pasadena, CA. One of the key recommendations represented in that document was the need for a longitudinal study of astronomers. It was recognized that in order to understand our own field, how it is evolving, and the impact on individuals, we need to track people over time. I will discuss the fundamental questions that led to the recommendation, and set the stage for the current (ongoing) longitudinal study.

Knezek, Patricia

2014-01-01

154

Note on longitudinal beam polairzation  

SciTech Connect

Longitudinal beam polarization achieved through g-2 precession is examined for the dependence of the power emitted as synchrotron radiation on the free length at the intersection. Using only dipoles for dispersion, the power doubles for every three meters of free length. The power can be reduced by using existing focusing elements to increase the dispersion, but this procedure also limits the luminosity because of chromatic aberration.

Wenzel, W.A.

1988-01-01

155

Comparison of Attenuation of Striated Muscle between Postmortem and Antemortem Computed Tomography: Results of a Longitudinal Study  

PubMed Central

Objective We evaluated the postmortem changes of striated muscle by comparing computed tomography (CT) images obtained postmortem and antemortem in the same patients. Materials and Methods We studied 33 consecutive patients who underwent antemortem CT, postmortem CT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. Postmortem CT was performed within 20 h after death and was followed by pathological autopsy. Pathological autopsy confirmed the absence of muscular diseases such as amyotrophic lateral sclerosis, muscular dystrophy, myositis, and myasthenia, in all of the patients. The CT attenuation values of four cardiac muscle sites (anterior wall of the left ventricle, left ventricular free wall, posterior wall of the left ventricle, and the ventricular septum) and two skeletal muscle sites (the pectoralis major muscle and the erector spinae muscle) were compared between antemortem and postmortem CT using paired t test. Results Striated muscle had significantly greater attenuation on postmortem CT than on antemortem CT (P<0.001) in all six tissue sites. No significant association was found between postmortem change in the CT attenuation of striated muscle and gender, age, or elapsed time since death. Conclusion This is the first longitudinal study to show hyperattenuation of striated muscle on postmortem CT images compared with antemortem CT images in the same patients. PMID:25365255

Okuma, Hidemi; Gonoi, Wataru; Ishida, Masanori; Shirota, Go; Shintani, Yukako; Abe, Hiroyuki; Fukayama, Masashi; Ohtomo, Kuni

2014-01-01

156

Parameterized Linear Longitudinal Airship Model  

NASA Technical Reports Server (NTRS)

A parameterized linear mathematical model of the longitudinal dynamics of an airship is undergoing development. This model is intended to be used in designing control systems for future airships that would operate in the atmospheres of Earth and remote planets. Heretofore, the development of linearized models of the longitudinal dynamics of airships has been costly in that it has been necessary to perform extensive flight testing and to use system-identification techniques to construct models that fit the flight-test data. The present model is a generic one that can be relatively easily specialized to approximate the dynamics of specific airships at specific operating points, without need for further system identification, and with significantly less flight testing. The approach taken in the present development is to merge the linearized dynamical equations of an airship with techniques for estimation of aircraft stability derivatives, and to thereby make it possible to construct a linearized dynamical model of the longitudinal dynamics of a specific airship from geometric and aerodynamic data pertaining to that airship. (It is also planned to develop a model of the lateral dynamics by use of the same methods.) All of the aerodynamic data needed to construct the model of a specific airship can be obtained from wind-tunnel testing and computational fluid dynamics

Kulczycki, Eric; Elfes, Alberto; Bayard, David; Quadrelli, Marco; Johnson, Joseph

2010-01-01

157

Antifungal activity of nettle (Urtica dioica L.), colocynth (Citrullus colocynthis L. Schrad), oleander (Nerium oleander L.) and konar (Ziziphus spina-christi L.) extracts on plants pathogenic fungi.  

PubMed

Anti-mycotic activity of the ethanol extracts from Nettle (Urtica dioica L.), Colocynth (Citrullus colocynthis L. Schrad), Konar (Ziziphus spina-christi L.) and Oleander (Nerium oleander L.) floral parts were screened in vitro against four important plant pathogenic fungi viz.; Alternaria alternate, Fusarium oxysporum, Fusarium solani and Rizoctonia solani using agar dilution bioassay. Extracts showed antifungal activity against all the tested fungi. Among the plants, Nettle and Colocynth were the most effective against A. alternate and R. solani while Oleander possesses the best inhibition on F. oxysporum and F. solani. Konar was the most effective extract by reducing the growth of Rizoctonia solani than other fungi. These results showed that extracts could be considered suitable alternatives to chemical additives for the control of fungal diseases in plants. PMID:19579919

Hadizadeh, I; Peivastegan, B; Kolahi, M

2009-01-01

158

Longitudinal Sampling and Aliasing in Spiral CT  

Microsoft Academic Search

Although analyses of in-plane aliasing have been done for conventional computed tomography (CT) images, longitudinal aliasing in spiral CT has not been properly in investigated. The authors propose a mathematical model of the three-dimensional (3-D) sampling scheme in spiral CT and analyze its effects on longitudinal aliasing. They investigated longitudinal aliasing as a function of the helical-interpolation algorithm, pitch, and

Shin Yi Yen; Chye Hwang Yan; Geoffrey D. Rubin; Sandy Napel

1999-01-01

159

DOCUMENTATION OF SCALES WISCONSIN LONGITUDINAL STUDY  

E-print Network

..................................................................................................................................13 Psychological Well-Being-Acceptance................................................................................................................ 25 7. Total Score for Psychological Well-BeingDOCUMENTATION OF SCALES in WISCONSIN LONGITUDINAL STUDY 1992-1993 Respondent Mail Questionnaire

Wisconsin at Madison, University of

160

Transverse-longitudinal integrated resonator  

DOEpatents

A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

Hutchinson, Donald P. (Knoxville, TN); Simpson, Marcus L. (Knoxville, TN); Simpson, John T. (Knoxville, TN)

2003-03-11

161

[Longitudinal stent deformation during bifurcation lesion treatment].  

PubMed

Longitudinal stent deformation is defined as a compression of stent length after its implantation. It's a rare complication but dangerous seen with several stents. We reported a case of longitudinal stent deformation during bifurcation lesion treatment with a Promus Element(®) and we perform a short review of this complication. PMID:25450995

Mami, Z; Monsegu, J

2014-12-01

162

MODELING LONGITUDINAL DAMAGE IN SHIP COLLISIONS  

E-print Network

SSC Report SR- 1426 MODELING LONGITUDINAL DAMAGE IN SHIP COLLISIONS SHIP STRUCTURE COMMITTEE 2004 and Subtitle Modeling LongitudinalDamage in Ship Collisions 5. Report Date October 2004 6. Performing or Grant No. DTCG32-02-C-R00002 12. Sponsoring Agency Name and Address Ship Structure Committee US Coast

Brown, Alan

163

Longitudinal Control of a Platoon of Vehicles  

Microsoft Academic Search

This paper presents a systematic analysis of a longitudinal control law for a platoon of non-identical vehicles using a non-linear model to represent the vehicle dynamics of each vehicle within the platoon. The basic idea is to take full advantage of recent advances in communication and measurement and using these advances in longitudinal control of a platoon of vehicles: in

Shahab Sheikholeslam; Charles A. Desoer

1990-01-01

164

Modeling a Longitudinal Relational Research Data Systems  

ERIC Educational Resources Information Center

A study was conducted to propose a research-based model for a longitudinal data research system that addressed recommendations from a synthesis of literature related to: (1) needs reported by the U.S. Department of Education, (2) the twelve mandatory elements that define federally approved state longitudinal data systems (SLDS), (3) the…

Olsen, Michelle D. Hunt

2010-01-01

165

Remittances matter: Longitudinal evidence from Albania  

E-print Network

EA 4272 Remittances matter: Longitudinal evidence from Albania Laetitia DUVAL (*) François,version1-1Oct2009 #12;Remittances matter: Longitudinal evidence from Albania # Laetitia Duval * François-Charles Wolff ** September 2009 Abstract: Using the LSMS panel data collected by the World Bank in Albania from

Paris-Sud XI, Université de

166

49 CFR 238.405 - Longitudinal static compressive strength.  

Code of Federal Regulations, 2013 CFR

... § 238.405 Longitudinal static compressive strength. ...resist a minimum longitudinal static compressive force of 2...resist a minimum longitudinal static compressive force of 800...to crush as part of the crash energy management design are not...

2013-10-01

167

49 CFR 238.405 - Longitudinal static compressive strength.  

Code of Federal Regulations, 2011 CFR

... § 238.405 Longitudinal static compressive strength. ...resist a minimum longitudinal static compressive force of 2...resist a minimum longitudinal static compressive force of 800...to crush as part of the crash energy management design are not...

2011-10-01

168

49 CFR 238.405 - Longitudinal static compressive strength.  

Code of Federal Regulations, 2012 CFR

... § 238.405 Longitudinal static compressive strength. ...resist a minimum longitudinal static compressive force of 2...resist a minimum longitudinal static compressive force of 800...to crush as part of the crash energy management design are not...

2012-10-01

169

49 CFR 238.405 - Longitudinal static compressive strength.  

Code of Federal Regulations, 2010 CFR

... § 238.405 Longitudinal static compressive strength. ...resist a minimum longitudinal static compressive force of 2...resist a minimum longitudinal static compressive force of 800...to crush as part of the crash energy management design are not...

2010-10-01

170

14 CFR 29.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2014 CFR

...false Demonstration of static longitudinal stability. 29.175 Section 29.175 Aeronautics...175 Demonstration of static longitudinal stability. (a) Climb. Static longitudinal stability must be shown in the climb condition at...

2014-01-01

171

14 CFR 27.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2013 CFR

...false Demonstration of static longitudinal stability. 27.175 Section 27.175 Aeronautics...175 Demonstration of static longitudinal stability. (a) Climb. Static longitudinal stability must be shown in the climb condition at...

2013-01-01

172

14 CFR 27.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2012 CFR

...false Demonstration of static longitudinal stability. 27.175 Section 27.175 Aeronautics...175 Demonstration of static longitudinal stability. (a) Climb. Static longitudinal stability must be shown in the climb condition at...

2012-01-01

173

14 CFR 23.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2012 CFR

... Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics...COMMUTER CATEGORY AIRPLANES Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal stability...

2012-01-01

174

14 CFR 25.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2013 CFR

... Demonstration of static longitudinal stability. 25.175 Section 25.175 Aeronautics...TRANSPORT CATEGORY AIRPLANES Flight Stability § 25.175 Demonstration of static longitudinal stability. Static longitudinal stability...

2013-01-01

175

14 CFR 23.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2014 CFR

... Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics...COMMUTER CATEGORY AIRPLANES Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal stability...

2014-01-01

176

14 CFR 27.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2014 CFR

...false Demonstration of static longitudinal stability. 27.175 Section 27.175 Aeronautics...175 Demonstration of static longitudinal stability. (a) Climb. Static longitudinal stability must be shown in the climb condition at...

2014-01-01

177

14 CFR 29.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2013 CFR

...false Demonstration of static longitudinal stability. 29.175 Section 29.175 Aeronautics...175 Demonstration of static longitudinal stability. (a) Climb. Static longitudinal stability must be shown in the climb condition at...

2013-01-01

178

14 CFR 23.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2013 CFR

... Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics...COMMUTER CATEGORY AIRPLANES Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal stability...

2013-01-01

179

14 CFR 23.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2011 CFR

... Demonstration of static longitudinal stability. 23.175 Section 23.175 Aeronautics...COMMUTER CATEGORY AIRPLANES Flight Stability § 23.175 Demonstration of static longitudinal stability. Static longitudinal stability...

2011-01-01

180

14 CFR 29.175 - Demonstration of static longitudinal stability.  

Code of Federal Regulations, 2012 CFR

...false Demonstration of static longitudinal stability. 29.175 Section 29.175 Aeronautics...175 Demonstration of static longitudinal stability. (a) Climb. Static longitudinal stability must be shown in the climb condition at...

2012-01-01

181

46 CFR 154.176 - Longitudinal contiguous hull structure.  

Code of Federal Regulations, 2010 CFR

... false Longitudinal contiguous hull structure. 154.176 Section 154.176 Shipping...Design, Construction and Equipment Hull Structure § 154.176 Longitudinal contiguous hull structure. (a) The longitudinal...

2010-10-01

182

Psychiatric resilience: longitudinal twin study  

PubMed Central

Objective There is great variability in response to stressful life events (SLEs), with some individuals demonstrating substantial psychiatric symptoms while others remain largely asymptomatic. The source of this variability is poorly understood. The present study aimed to examine the genetic and environmental underpinning of resilience, defined as the difference between the twins’ total score on a broad measure of internalizing symptoms and their predicted score based on their cumulative exposure to SLEs. Method SLE exposure and internalizing symptoms were assessed at two time points in 7,500 adult twins. Using the residual between actual and predicted internalizing symptom total score, twin modeling was conducted for each wave separately, as well as longitudinally. Quantitative and qualitative sex effects were also tested. Results Resilience was found to have a mild to moderate genetic heritability at each individual wave (~31%). Additionally, qualitative sex effects were found. Incorporating error of measurement into the model increased the estimated heritability for the latent construct of resilience (~50%). Unconfounded by measurement error and occasion specific effects, environmental influences contributed roughly equally to determining the individual level of resilience. Conclusions Genetic factors influence the level of psychiatric resilience, and are largely stable over time. The genes that impact on resilience are not entirely the same in males and females, although the degree of heritability is equal across the sexes. Environmental influences can also have an enduring effect on resilience. The present findings of the genetic and environmental influences on adaptation to SLEs clarify the sources of individual variation to environmental stressors. PMID:24723629

Amstadter, Ananda B.; Myers, John M.; Kendler, Kenneth S.

2014-01-01

183

Longitudinal Variations in Jupiter's Winds  

NASA Technical Reports Server (NTRS)

Long-term studies of Jupiter's zonal wind field revealed temporal variations on the order of 20 to 40 m/s at many latitudes, greater than the typical data uncertainties of 1 to 10 m/s. No definitive periodicities were evident, however, though some latitudinally-confined signals did appear at periods relevant to the Quasi- Quadrennial Oscillation (Simon-Miller & Gierasch, Icarus, in press). As the QQO appears, from vertical temperature profiles, to propagate downward, it is unclear why a signal is not more obvious, unless other processes dominate over possibly weaker forcing from the QQO. An additional complication is that zonal wind profiles represent an average over some particular set of longitudes for an image pair and most data sets do not offer global wind coverage. Lien avoiding known features, such as the large anticyclonic vortices especially prevalent in the south, there can be distinct variations in longitude. We present results on the full wind field from Voyager and Cassini data, showing apparent longitudinal variations of up to 60 m/s or more. These are particularly obvious near disruptions such as the South Equatorial Disturbance, even when the feature itself is not clearly visible. These two dates represent very different states of the planet for comparison: Voyagers 1 & 2 flew by Jupiter shortly after a global upheaval, while many regions were in a disturbed state, while the Cassini view is typical of a more quiescent period present during much of the 1990s and early 2000s.

Simon-Miller, Amy A.; Gierasch, P. J.; Tierney, G.

2010-01-01

184

Longitudinal Dynamics and Tomography in the Tevatron  

DOE PAGESBeta

Motivated by the desire to understand the longitudinal effects of beam-beam forces, we study the longitudinal dynamics of protons and anti-protons at injection and top energy in the Tevatron. Multi-turn data of the longitudinal profiles are captured to reveal information about frequencies of oscillation, and changes in the bunch distributions. Tomographic reconstruction is used to create phase space maps which are subsequently used to find the momentum distributions. Changes in these distributions for both proton and anti-proton beams are also followed through the operational cycle. We report on the details of interesting dynamics and some unexpected findings.

Stogin, J [Princeton U.; Sen, T [Fermilab; Moore, R S [Fermilab

2012-01-10

185

Interaction of longitudinal modes in MWCG  

NASA Astrophysics Data System (ADS)

Interaction of relativistic electron beam with the electromagnetic field of two longitudinal modes near the (pi) -type oscillations of TM01-mode has been investigated by means of a nonlinear code in the overmoded one- and two-sectional slow-wave structures (SWS). Longitudinal mode interaction in Cerenkov one-sectional generators has shown to result in the changes of generation regime from the stable to unstable one. For a multiwave Cerenkov generator with a two-sectional SWS a generation regime classification depending on the type of longitudinal mode interaction has been carried out. Numerical simulation results are compared with the previously obtained experimental data.

Koshelev, Vladimir I.; Deichuly, Michail P.; Petkun, Andrei A.

1999-07-01

186

LONGITUDINAL TUNING OF THE SNS SUPERCONDUCTING LINAC  

SciTech Connect

The SNS superconducting linac delivers about 1 GeV of energy driven by self-consistent RF cavities. Here, we present an experience of the longitudinal tune-up of the SNS linac where a new application for quick RF phase setup and cavity fault adaptation was created. The routine of superconducting linac tune-up, longitudinal beam manipulation, and radio frequency cavity phase scaling for beam state recovery is presented. The application has direct value for beam optics study and will serve as the basis for longitudinal beam-size manipulation for the laser stripping project.

Gorlov, Timofey V [ORNL] [ORNL

2012-01-01

187

Longitudinal forces in pinched electric currents  

E-print Network

It is shown that the theory of Mbelek and Lachi\\`eze-Rey predicts longitudinal forces of gravitational origin in pinched current distributions, with magnitudes large enough to have noticeable effects.

F. O. Minotti

2014-02-13

188

ADDHEALTH - NATIONAL LONGITUDINAL STUDY OF ADOLESCENT HEALTH  

EPA Science Inventory

This study provides a comprehensive view of the health and health behaviors of adolescents and the antecedents - personal, interpersonal, familial, and environmental of these outcomes. The study features a longitudinal, multi-level design with independent measurement at the indiv...

189

The Lighthouse Program: A Longitudinal Research Project.  

ERIC Educational Resources Information Center

Longitudinal data are presented from the Lighthouse Program for gifted students which features cluster grouping and a quota identification systems to ensure proportionate inclusion of minority students. (Author/CL)

LaRose, Barbara

1986-01-01

190

Venturing a 30Year Longitudinal Study  

Microsoft Academic Search

Longitudinal inquiry has long been recognized as a uniquely powerful method for seeking understanding of psychological development. A 30-year longitudinal venture is described—its theoretical motivation, methodological rationale, and details of implementation. Some of the novel and implicative findings the study has generated are briefly described. Common to all of the results is an absolute reliance on long-term, widely ranging, independent

Jack Block; Jeanne H. Block

2006-01-01

191

Spinal dysraphism: genetic relation to neural tube malformations.  

PubMed Central

The families of 207 index patients treated for spinal dysraphism at The Hospital for Sick Children were studied to discover whether the condition was aetiologically related to the classical neural tube malformation--spina bifida cystica and anencephaly. The index patients had all had a tethered conus medullaris and one or more of a variety of anomalies of the spinal cord, vertebrae, or skin overlying the vertebral column. Of 364 sibs of index patients, 9 had an encephaly and 6 spina bifida cystica, a pro-proportion of 4.12%. This approximates to the proportion of sibs affected by neural tube malformations in the London region when the index patients themselves have spina bifida or anencephaly. It is, therefore, appropriate that the mothers of children with spinal dysraphism should be offered prenatal screening for neural tube malformations. PMID:794474

Carter, C O; Evans, K A; Till, K

1976-01-01

192

COMPARISON OF POSTURAL CHANGES AND MUSCLE FATIGUE BETWEEN TWO TYPES OF LUMBAR SUPPORT: A PROSPECTIVE LONGITUDINAL STUDY.  

PubMed

Background: Lumbar supports are used in the management of low back pain (LBP). Although various types of lumbar supports are available, insufficient evidence exists regarding their effectiveness. The aim of this study was to investigate the effect of two types of lumbar support on postural change and muscle fatigue in a prospective longitudinal study.Methods: A total of 144 subjects (9 men and 135 women) with LBP were enrolled in this study. Subjects were divided into 2 groups: a conventional lumbosacral support (LS) group and a wear-type support (SW) group. They filled in questionnaires that included the Short Form 36-Item Health Survey (SF-36), the Roland-Morris Disability Questionnaire (RDQ), and a questionnaire that evaluated the severity of LBP at baseline, 1, 2, and 3 months. The first 40 enrolled subjects were investigated for muscle fatigue and walking efficacy during a gait-loading test, and posture at baseline, 1 month, and 3 months.Results: The intensity of LBP and the number of days with LBP significantly decreased over time in both groups. The decrease was similar in both groups at each time point. Wearing either support for 3 months did not induce erector spinae muscle fatigue. Furthermore, walking efficacy improved but spinal alignment was not affected by either support. Subjects in the SW group reported that the support was comfortable to wear for long periods, while subjects in the LS group mentioned that the LS relieved LBP by tightly supporting the lower back.Conclusion: Both types of support reduced mild LBP and improved walking efficiency without causing muscle fatigue. PMID:25410441

Saito, Hiroharu; Sekiguchi, Miho; Yamada, Hiroyuki; Kubota, Tomoyuki; Shigihara, Tomohiko; Iwasaki, Tetsuji; Yabuki, Shoji; Konno, Shinichi

2014-11-19

193

Neural tube defects in New South Wales: management and preventive policies, 1965-1980.  

PubMed

This paper reviews the results of the programme of antenatal testing and selective termination of fetuses with anencephaly and spina bifida in New South Wales over the last eight years. It discusses the problems associated with pregnancy screening, with reference to those involved in selection for treatment of newborn infants with spina bifida. The incidence of neural tube defects has been declining, and this, although possibly the result of early termination of affected fetuses, may have its basis in a worldwide trend. Preventive action based on a more precise understanding of aetiological factors will further decrease the incidence, thereby reducing the load of long-term handicapped survivors. PMID:6174849

Field, B R; Kerr, C B

194

Visual analysis of longitudinal brain tumor perfusion  

NASA Astrophysics Data System (ADS)

In clinical research on diagnosis and evaluation of brain tumors, longitudinal perfusion MRI studies are acquired for tumor grading as well as to monitor and assess treatment response and patient prognosis. Within this work, we demonstrate how visual analysis techniques can be adapted to multidimensional datasets from such studies within a framework to support the computer-aided diagnosis of brain tumors. Our solution builds on two innovations: First, we introduce a pipeline yielding comparative, co-registered quantitative perfusion parameter maps over all time steps of the longitudinal study. Second, based on these time-dependent parameter maps, visual analysis methods were developed and adapted to reveal valuable insight into tumor progression, especially regarding the clinical research area of low grade glioma transformation into high grade gliomas. Our examination of four longitudinal brain studies demonstrates the suitability of the presented visual analysis methods and comprises new possibilities for the clinical researcher to characterize the development of low grade gliomas.

Glaßer, Sylvia; Oeltze, Steffen; Preim, Uta; Bjørnerud, Atle; Hauser, Helwig; Preim, Bernhard

2013-02-01

195

Longitudinal control of intense charged particle beams  

NASA Astrophysics Data System (ADS)

As the accelerator frontier shifts from high energy to high intensity, accelerator facilities are demanding beams with higher quality. Applications such as Free Electron Lasers and Inertial Fusion Energy production require the minimization of both transverse emittance and longitudinal energy spread throughout the accelerator. Fluctuations in beam energy or density at the low-energy side of the accelerator, where space-charge forces dominate, may lead to larger modulations downstream and the eventual degradation of the overall beam quality. Thus it is important to understand the phenomenon that causes these modulations in space-charge dominated beams and be able to control them. This dissertation presents an experimental study on the longitudinal control of a space-charge dominated beam in the University of Maryland Electron Ring (UMER). UMER is a scaled model of a high-intensity beam system, which uses low-energy high-current electron beams to study the physics of space-charge. Using this facility, I have successfully applied longitudinal focusing to the beam edges, significantly lengthening the propagation distance of the beam to 1000 turns (>11.52 km). This is a factor of 10 greater than the original design conceived for the accelerator. At this injected current, the space-charge intensity is several times larger than the standard limit for storage rings, an encouraging result that raises the possibility of operating these machines with far more space-charge than previously assumed possible. I have also explored the transverse/longitudinal correlations that result when a beam is left to expand longitudinally under its own space-charge forces. In this situation, the beam ends develop a large correlated energy spread. Through indirect measurements, I have inferred the correlated energy profile along the bunch length. When the bunch is contained using longitudinal focusing, I have shown that errors in the applied focusing fields induce space-charge waves at the bunch edges that propagate into the middle region of the beam. In some cases, these waves sustain multiple reflections before damping away. I conclude that space-charge in an intense beam without longitudinal focusing can cause the bunch to develop a large correlated energy spread, increasing the risk that the beam is lost to the pipe walls as it requires a larger aperture. When longitudinal focusing is applied however, we are able to transport the beam over a much longer path length and reduce the correlated energy spread.

Beaudoin, Brian Louis

2011-12-01

196

Symmetric Diffeomorphic Modeling of Longitudinal Structural MRI  

PubMed Central

This technology report describes the longitudinal registration approach that we intend to incorporate into SPM12. It essentially describes a group-wise intra-subject modeling framework, which combines diffeomorphic and rigid-body registration, incorporating a correction for the intensity inhomogeneity artifact usually seen in MRI data. Emphasis is placed on achieving internal consistency and accounting for many of the mathematical subtleties that most implementations overlook. The implementation was evaluated using examples from the OASIS Longitudinal MRI Data in Non-demented and Demented Older Adults. PMID:23386806

Ashburner, John; Ridgway, Gerard R.

2013-01-01

197

The Tevatron bunch by bunch longitudinal dampers  

SciTech Connect

We describe in this paper the Tevatron bunch by bunch dampers. The goal of the dampers is to stop the spontaneous longitudinal beam size blowup of the protons during a store. We will go through the theory and also show the measured results during the commissioning of this system. The system is currently operational and have stopped the beam blowups during a store.

Cheng-Yang Tan and James Steimel

2002-09-25

198

Longitudinal data analysis using generalized linear models  

Microsoft Academic Search

SUMMARY This paper proposes an extension of generalized linear models to the analysis of longitudinal data. We introduce a class of estimating equations that give consistent estimates of the regression parameters and of their variance under mild assumptions about the time dependence. The estimating equations are derived without specifying the joint distribution of a subject's observations yet they reduce to

KUNG-YEE LIANG; SCOTT L. ZEGER

1986-01-01

199

Longitudinal Associations Between Reading and Mathematics Achievement  

Microsoft Academic Search

The association between early reading skills and changes in mathematics was examined in a large, low-income sample to determine whether students who have a greater level of reading skills in early elementary school exhibit more rapid gains in tests of mathematics. The longitudinal associations between third grade reading comprehension and changes in three components of mathematics achievement (Problem Solving and

Kevin J. Grimm

2008-01-01

200

ORIGINAL RESEARCH Human middle longitudinal fascicle: segregation  

E-print Network

association fiber tracts, it has only recently been discovered in humans. In this high angular resolution and schizophrenia. Keywords High-angular resolution diffusion imaging . Middle longitudinal fascicle . Middle diffusion imaging (HARDI) MRI study, we delin- eated the two major fiber connections of the human Md

Dickerson, Brad

201

Reengineering service operations: a longitudinal case study  

Microsoft Academic Search

Examples of business process reengineering efforts have tended to emphasize manufacturing applications over service operations. This paper reports on a recently completed longitudinal reengineering project conducted by the authors in a service context. Key lessons learned from the experiences of the case study are presented in the form of propositions. Based on these propositions, a process model for successfully planning

Ram Narasimhan; Jayanth Jayaram

1998-01-01

202

NLS Handbook, 2005. National Longitudinal Surveys  

ERIC Educational Resources Information Center

The National Longitudinal Surveys (NLS), sponsored by the U.S. Bureau of Labor Statistics (BLS), are a set of surveys designed to gather information at multiple points in time on the labor market experiences of groups of men and women. Each of the cohorts has been selected to represent all people living in the United States at the initial…

Bureau of Labor Statistics, 2006

2006-01-01

203

Empirical data on longitudinal dispersion in rivers  

USGS Publications Warehouse

Empirical data on longitudinal dispersion process in rivers are compiled from published and unpublished sources. Fifty-one sets of data, covering flows from about 30 cubic feet per second to 241,000 cubic feet per second (0.85 to 6,820 cubic meters per second), are analyzed graphically.

Nordin, Carl F.; Sabol, George V.

1974-01-01

204

Emotion Regulation and Childhood Aggression: Longitudinal Associations  

ERIC Educational Resources Information Center

Accumulating evidence suggests that emotion dysregulation is associated with psychopathology. This paper provides a review of recent longitudinal studies that investigate the relationship between emotion regulation and aggressive behavior in childhood age. While there is substantial evidence for assuming a close relation of emotion regulation and…

Roll, Judith; Koglin, Ute; Petermann, Franz

2012-01-01

205

Issues in Longitudinal Research on Motivation  

ERIC Educational Resources Information Center

This paper discusses two methodological issues regarding the analysis of longitudinal data using structural equation modeling that emerged during the reconsideration of the analysis of a recent study on the relationship between academic motivation and language achievement in elementary education [Stoel R.D., Peetsma, T.T.D. and Roeleveld, J.…

Stoel, Reinoud D.; Roeleveld, Jaap; Peetsma, Thea; van den Wittenboer, Godfried; Hox, Joop

2006-01-01

206

EXPLAINING DISCREPANCIES BETWEEN LONGITUDINAL AND CROSS-SECTIONAL MODELS  

EPA Science Inventory

Discrepancies between estimates obtained from longitudinal studies analyzed cross-sectionally and longitudinally pose questions about the validity of cross-sectional estimates of change. n some cases these discrepancies are the result of period effects, cohort effects, or selecti...

207

Using the Longitudinal Study as a Central Teaching Focus.  

ERIC Educational Resources Information Center

Argues that treatment of one investigative longitudinal topic from start to finish in a high school biology class can illustrate many major ideas and concepts. Discusses ways to use various longitudinal studies of plant growth with General Biology classes. (WRM)

Demchik, Michael J.

1999-01-01

208

Research article The relationship between acculturation preferences and prejudice: Longitudinal  

E-print Network

Research article The relationship between acculturation preferences and prejudice: Longitudinal the reciprocal effects of acculturation preferences and prejudice among ethnic minorities and majorities. Data on acculturation preferences but also the reverse for both majority and minority members. The mutual longitudinal

Royal Holloway, University of London

209

46 CFR 172.095 - Intact longitudinal stability.  

Code of Federal Regulations, 2010 CFR

...false Intact longitudinal stability. 172.095 Section 172...CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING...095 Intact longitudinal stability. Each tank barge must...loading and operation, at least equal to the following:...

2010-10-01

210

Longitudinal dunes on Mars: Relation to current wind regimes  

NASA Technical Reports Server (NTRS)

Longitudinal dunes are extremely rare on Mars, but constitute a substantial fraction of terrestrial desert dunes. We report finding isolated examples of longitudinal dunes on Mars and relate their occurence to expected sand transport regimes. Terrestrial longitudinal dunes form in bimodal and multimodal transport regimes. General circulation models and streak data indicate that bimodal and multimodal transport of sand should be very rare on Mars. Thus the dearth of longitudinal dunes on Mars is consistant with their apparent formation conditions on Earth.

Lee, Pascal; Thomas, Peter C.

1995-01-01

211

Longitudinal dunes on Mars: Relation to current wind regimes  

NASA Technical Reports Server (NTRS)

Longitudinal dunes are extremely rare on Mars, but constitute a substantial fraction of terrestrial desert dunes. We report finding isolated examples of longitudinal dunes on Mars and relate their occurrence to expected sand transport regimes. Terrestrial longitudinal dunes form in bimodal and multimodal transport regimes. General circulation models and streak data indicate that bimodal and multimodal transport of sand should be very rare on Mars. Thus the dearth of longitudinal dunes on Mars is consistent with their apparent formation conditions on Earth.

Lee, Pascal; Thomas, Peter C.

1995-01-01

212

Factorization properties of the diffraction dissociation of longitudinal photons  

Microsoft Academic Search

We develop the pQCD description of the diffraction dissociation (DD) of longitudinal pho- tons. We demonstrate that the longitudinal diffractive structure function does not factor into the flux of pomerons and the partonic structure function of the pomeron, thus defying the usually assumed Regge factorization. In contrast to DD of the transverse photons, DD of the longitudinal photons is strongly

M. Genovesea; B. G. Zakharovd; L. D. Landau

213

Ultrasonic rock drilling devices using longitudinal-torsional compound vibration  

Microsoft Academic Search

Nasa funded studies have proven that ultrasonics is a viable technology for extraterrestrial drilling. Previous research by the authors has indicated that ultrasonic longitudinal-torsional coupled vibrations may improve rock excavation. In this study, two approaches to the development of torsional output from a Langevin transducer are pursued: coupling the longitudinal mode with a torsional mode and degenerating the longitudinal mode

Patrick Harkness; Andrea Cardoni; Margaret Lucas

2009-01-01

214

STAR results on longitudinal spin dynamics  

E-print Network

We present preliminary results on the double longitudinal spin asymmetries A_LL in inclusive jet production and the longitudinal spin transfer asymmetries D_LL in inclusive Lambda and anti-Lambda hyperon production. The data amount to about 0.5 pb-1 collected at RHIC in 2003 and 2004 with beam polarizations up to 45 %. The jet A_LL asymmetries, measured over 5 < pT < 17 GeV/c, are consistent with evaluations based on deep-inelastic scattering parametrizations for the gluon polarization in the nucleon, and disfavor large positive values of gluon polarization in the nucleon. The Lambda and anti-Lambda D_LL, measured at midrapidity and at low average transverse momentum of 1.5 GeV/c, are consistent with zero within their dominant statistical uncertainties.

Joanna Kiryluk; for the STAR Collaboration

2006-08-08

215

A Longitudinal Analysis of Satisfaction and Profitability  

Microsoft Academic Search

Recently, significant attention has been focused on customer satisfaction. However, few studies link satisfaction with performance, and even fewer studies examine this link through the use of time-series data. In this study, a longitudinal analysis of satisfaction and performance for a national chain of fast-food restaurants is conducted. A total of 342,308 consumer responses, 3,009 employee responses, and 12 months

Kenneth L. Bernhardt; Naveen Donthu; Pamela A. Kennett

2000-01-01

216

RADON reconstruction in longitudinal phase space  

SciTech Connect

Longitudinal particle motion in circular accelerators is typically monitoring by one dimensional (1-D) profiles. Adiabatic particle motion in two dimensional (2-D) phase space can be reconstructed with tomographic techniques, using 1-D profiles. A computer program RADON has been developed in C++ to process digitized mountain range data and perform the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC).

Mane, V.; Peggs, S.; Wei, J.

1997-07-01

217

Extensions of the longitudinal envelope equation  

SciTech Connect

Recently, longitudinal space charge effects have become of increased importance in a variety of dynamical situations. The CEBAF FEL injector beam dynamics shows large space-charge effects, even at 10 MeV ({gamma} {approx} 20). Space-charge dominated longitudinal motion has also been studied in the IUCF ion storage ring. Previously a longitudinal envelope equation with a self-consistent phase-space distribution has been developed, and has been of considerable use in analyzing the motion of these cases. Longitudinal motion in detailed agreement with this envelope equation has been observed at the U. of Maryland Laboratory for Plasma Research, and at the GSI electron cooling storage ring ESR, as well as at the IUCF. However, the initial presentation in ref. 4 used non-relativistic linear-accelerator bunching motion as a simplifying approximation in order to avoid inadvertent errors and minimize misprints, and must be adapted to include relativistic and/or synchrotron effects. In the present note we extend the envelope equation formulae to include relativistic, synchrotron, and acceleration effects, and define the various factors in the equations in explicit detail. The object is to obtain a set of debugged formulae for these extended cases, with all of the various factors defined explicitly, so that the formulae can be used as a reference without repetitive rederivations. The usual ambiguities over emittance definitions and units and {beta}, {gamma}, g factors should be resolved. The reader (or readers) is invited to discover any remaining errors, ambiguities or misprints for removal in the next edition.

Neuffer, David

1997-04-30

218

Extensions of the longitudinal envelope equation  

SciTech Connect

Recently, longitudinal space charge effects have become of increased importance in a variety of dynamical situations. The CEBAF FEL injector beam dynamics shows large space-charge effects, even at 10 MeV ({gamma} {approx} 20). Space-charge dominated longitudinal motion has also been studied in the IUCF ion storage ring. Previously a longitudinal envelope equation with a self-consistent phase-space distribution has been developed, and has been of considerable use in analyzing the motion of these cases. Longitudinal motion in detailed agreement with this envelope equation has been observed at the U. of Maryland Laboratory for Plasma Research, and at the GSI electron cooling storage ring ESR, as well as at the IUCF. However, the initial presentation in ref. 4 used non-relativistic linear- accelerator bunching motion as a simplifying approximation in order to avoid inadvertent errors and minimize misprints, and must be adapted to include relativistic and/or synchrotron effects. In the present note we extend the envelope equation formulae to include relativistic, synchrotron, and acceleration effects, and define the various factors in the equations in explicit detail. The object is to obtain a set of debugged formulae for these extended cases, with all of the various factors defined explicitly, so that the formulae can be used as a reference without repetitive rederivations. The usual ambiguities over emittance definitions and units and {beta}, {gamma}, g factors should be resolved. The reader (or readers) is invited to discover any remaining errors, ambiguities or misprints for removal in the next edition. 12 refs.

Neuffer, D.

1996-12-01

219

Longitudinal plasma oscillations in an electric field  

Microsoft Academic Search

The properties of longitudinal plasma oscillations in an external electric field are investigated. In a completely linear approximation, it is found that the direct-current electric field introduces essentially no new effects. A quasi-linear approximation is also considered, in which couplings between different plasma modes are neglected while the space-averaged distribution functions are assumed to be approximately independent of time. In

B. D. Fried; M. Gell-mann; J. D. Jackson; H. W. Wyld

1960-01-01

220

Kml: A package to cluster longitudinal data  

Microsoft Academic Search

Cohort studies are becoming essential tools in epidemiological research. In these studies, measurements are not restricted to single variables but can be seen as trajectories. Thus, an important question concerns the existence of homogeneous patient trajectories.KmL is an R package providing an implementation of k-means designed to work specifically on longitudinal data. It provides several different techniques for dealing with

Christophe Genolini; Bruno Falissard

2011-01-01

221

CLADA: Cortical Longitudinal Atrophy Detection Algorithm  

PubMed Central

Measurement of changes in brain cortical thickness is useful for assessment of regional gray matter atrophy in neurodegenerative conditions. A new longitudinal method, called CLADA (cortical longitudinal atrophy detection algorithm), has been developed for measurement of changes in cortical thickness in magnetic resonance images (MRI) acquired over time. CLADA creates a subject-specific cortical model which is longitudinally deformed to match images from individual time points. The algorithm was designed to work reliably for lower-resolution images, such as the MRIs with 1×1×5mm3 voxels previously acquired for many clinical trials in multiple sclerosis (MS). CLADA was evaluated to determine reproducibility, accuracy, and sensitivity. Scan-rescan variability was 0.45% for images with 1mm3 isotropic voxels and 0.77% for images with 1×1×5 mm3 voxels. The mean absolute accuracy error was 0.43 mm, as determined by comparison of CLADA measurements to cortical thickness measured directly in post- mortem tissue. CLADA’s sensitivity for correctly detecting at least 0.1 mm change was 86% in a simulation study. A comparison to FreeSurfer showed good agreement (Pearson correlation = 0.73 for global mean thickness). CLADA was also applied to MRIs acquired over 18 months in secondary progressive MS patients who were imaged at two different resolutions. Cortical thinning was detected in this group in both the lower and higher resolution images. CLADA detected a higher rate of cortical thinning in MS patients compared to healthy controls over 2 years. These results show that CLADA can be used for reliable measurement of cortical atrophy in longitudinal studies, even in lower resolution images. PMID:20674750

Nakamura, Kunio; Fox, Robert; Fisher, Elizabeth

2010-01-01

222

Random-effects models for longitudinal data  

Microsoft Academic Search

Models for the analysis of longitudinal data must recognize the relationship between serial observations on the same unit. Multivariate models with general covariance structure are often difficult to apply to highly unbalanced data, whereas two-stage random-effects models can be used easily. In two-stage models, the probability distributions for the response vectors of different individuals belong to a single family, but

N. M. Laird; J. H. Ware

1982-01-01

223

Longitudinal analysis of attitudes toward wolves.  

PubMed

Understanding individual attitudes and how these predict overt opposition to predator conservation or direct, covert action against predators will help to recover and maintain them. Studies of attitudes toward wild animals rely primarily on samples of individuals at a single time point. We examined longitudinal change in individuals' attitudes toward gray wolves (Canis lupus). In the contiguous United States, amidst persistent controversy and opposition, abundances of gray wolves are at their highest in 60 years. We used mailed surveys to sample 1892 residents of Wisconsin in 2001 or 2004 and then resampled 656 of these individuals who resided in wolf range in 2009. Our study spanned a period of policy shifts and increasing wolf abundance. Over time, the 656 respondents increased agreement with statements reflecting fear of wolves, the belief that wolves compete with hunters for deer (Odocoileus virginianus), and inclination to poach a wolf. Endorsement of lethal control of wolves by the state and public hunting of wolves also increased. Neither the time span over which respondents reported exposure to wolves locally nor self-reported losses of domestic animals to wolves correlated with changes in attitude. We predict future increases in legal and illegal killing of wolves that may reduce their abundance in Wisconsin unless interventions are implemented to improve attitudes and behavior toward wolves. To assess whether interventions change attitudes, longitudinal studies like ours are needed. Análisis Longitudinal de las Actitudes Hacia Lobos. PMID:23293913

Treves, Adrian; Naughton-Treves, Lisa; Shelley, Victoria

2013-04-01

224

Magnetization transfer induced biexponential longitudinal relaxation.  

PubMed

Longitudinal relaxation of brain water (1)H magnetization in mammalian brain in vivo is typically analyzed on a per-voxel basis using a monoexponential model, thereby assigning a single relaxation time constant to all (1)H magnetization within a given voxel. This approach was tested by obtaining inversion recovery (IR) data from gray matter of rats at 64 exponentially spaced recovery times. Using Bayesian probability for model selection, brain water data were best represented by a biexponential function characterized by fast and slow relaxation components. At 4.7T, the amplitude fraction of the rapidly relaxing component is 3.4% +/- 0.7% with a rate constant of 44 +/- 12 s(-1) (mean +/- SD; 174 voxels from four rats). The rate constant of the slow relaxing component is 0.66 +/- 0.04 s(-1). At 11.7T, the corresponding values are 6.9% +/- 0.9%, 19 +/- 5 s(-1), and 0.48 +/- 0.02 s(-1) (151 voxels from four rats). Several putative mechanisms for biexponential relaxation behavior were evaluated, and magnetization transfer (MT) between bulk water protons and nonaqueous protons was determined to be the source of biexponential longitudinal relaxation. MR methods requiring accurate quantification of longitudinal relaxation may need to take this effect explicitly into account. PMID:18759367

Prantner, Andrew M; Bretthorst, G Larry; Neil, Jeffrey J; Garbow, Joel R; Ackerman, Joseph J H

2008-09-01

225

Modeling HIF relevant longitudinal dynamics in UMER  

NASA Astrophysics Data System (ADS)

The foremost challenge for Heavy-Ion Fusion (HIF) is achieving sufficiently low emittances and small energy spreads in the presence of intense space-charge, to achieve the high deposition densities necessary for pellet ignition. The University of Maryland Electron Ring (UMER) uses intense low-energy electron beams to access the scaled physics of HIF drivers. In particular, the long path-length propagation in UMER presents an opportunity to study, at realistic scales, the longitudinal beam dynamics and manipulations required for such a driver. With the use of induction modules, as in the ion machines such as NDCX-II, the resulting bunch dynamics show evidence of space-charge waves excited by an initial mismatch between the detailed initial beam distribution at the bunch ends and the applied focusing waveforms, persisting with multiple damped reflections propagating along the bunch flat-top. Using the induction module we are able to suppress space-charge waves with great accuracy, at amplitudes that include wave steepening prior to the formation of solitary wave trains. The longitudinal dynamics largely dominates when no containment fields are applied, coupling through the natural chromaticity of the ring even within the first turn. After subsequent turns, the bunch elongates and wraps the circumference of the machine multiple times; eventually reaching a point of instability that has also been shown through simulation, obtaining excellent agreement when the detailed longitudinal dynamics of the experiment are carefully incorporated into the model.

Beaudoin, B. L.; Bernal, S.; Blanco, C.; Haber, I.; Kishek, R. A.; Koeth, T.; Mo, Y.

2014-01-01

226

Longitudinal evolution of Suez rift structure, Egypt  

SciTech Connect

A three-dimensional study of the structure of the Suez Rift has been carried out using field and subsurface data in an attempt to determine the role of transverse faults and the longitudinal evolution of the rift. As in most intracontinental rifts, the structure of the Gulf of Suez area is governed by normal faults and tilted blocks, whose crests constitute the main target of exploratory wells. The fault pattern consists of two major sets of trends: (1) longitudinal faults parallel with the rift axis and created in an extensional regime, trending east-northeast-west-southwest, and (2) transverse faults with north-south to north-northeast-south-southwest dominant trend. The transverse faults are inherited passive discontinuities, whereas most of the longitudinal faults were created during the Neogene in a purely extensional regime. Both sets were simultaneously active, producing a zigzag pattern and rhombic-shaped blocks. The transverse faults can show horizontal strike-slip components and act as relays between major normal faults.

Colletta, B.; Le Quellec, P.; Letouzey, J.; Moretti, I.

1988-01-01

227

Longitudinal dispersion coefficients in natural channels.  

PubMed

Details are given herein, of the development of an equation for predicting the longitudinal dispersion coefficient in riverine flows, based on 81 sets of measured data, and obtained from 30 rivers in the USA. This equation relates the dispersion coefficient to the hydraulic and geometric parameters of the flow and has been derived using dimensional and regression analysis, with a high correlation coefficient (i.e. R2 = 0.84). The formulation has been compared with many other existing empirical equations, frequently used to predict the longitudinal dispersion coefficient in riverine flows, with the comparisons based on four different statistical methods. These statistical comparisons have shown that the new equation appears to be more accurate than the other equations considered. The new dispersion equation was then linearly combined with a similar equation recently proposed by Seo and Cheong (J. Hydraul. Eng. ASCE 124 (1998) 25) and this combined equation was then also analysed using statistical methods. The existing empirical equations used to estimate the longitudinal dispersion coefficient and the new equations proposed in this study were included in the advective dispersion equation to predict the suspended sediment concentrations at three sites in the Humber Estuary sited along the northeast coast of England. The average percentage errors between the predicted- and measured-field data for the proposed new dispersion equations were less than those obtained using the previously documented equations. PMID:11996348

Kashefipour, Seyed M; Falconer, Roger A

2002-03-01

228

Multilevel Cross-dependent Binary Longitudinal Data  

PubMed Central

We provide insights into new methodology for the analysis of multilevel binary data observed longitudinally, when the repeated longitudinal measurements are correlated. The proposed model is logistic functional regression conditioned on three latent processes describing the within- and between-variability, and describing the cross-dependence of the repeated longitudinal measurements. We estimate the model components without employing mixed-effects modeling but assuming an approximation to the logistic link function. The primary objectives of this paper are to highlight the challenges in the estimation of the model components, to compare two approximations to the logistic regression function, linear and exponential, and to discuss their advantages and limitations. The linear approximation is computationally efficient whereas the exponential approximation applies for rare events functional data. Our methods are inspired by and applied to a scientific experiment on spectral backscatter from long range infrared light detection and ranging (LIDAR) data. The models are general and relevant to many new binary functional data sets, with or without dependence between repeated functional measurements. PMID:24131242

Staicu, Ana-Maria; Carroll, Raymond J.

2013-01-01

229

PREPROCESSING MAGNETIC FIELDS WITH CHROMOSPHERIC LONGITUDINAL FIELDS  

SciTech Connect

Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new preprocessing for the NLFFF extrapolation. Through this preprocessing, we expect to obtain magnetic field data similar to those in the chromosphere. In our preprocessing, we add a new term concerning chromospheric longitudinal fields into the optimization function proposed by Wiegelmann et al. We perform a parameter survey of six free parameters to find minimum force- and torque-freeness with the simulated-annealing method. Analyzed data are a photospheric vector magnetogram of AR 10953 observed with the Hinode spectropolarimeter and a chromospheric longitudinal magnetogram observed with SOLIS spectropolarimeter. It is found that some preprocessed fields show the smallest force- and torque-freeness and are very similar to the chromospheric longitudinal fields. On the other hand, other preprocessed fields show noisy maps, although the force- and torque-freeness are of the same order. By analyzing preprocessed noisy maps in the wave number space, we found that small and large wave number components balance out on the force-free index. We also discuss our iteration limit of the simulated-annealing method and magnetic structure broadening in the chromosphere.

Yamamoto, Tetsuya T. [Solar-Terrestrial Environment Laboratory, Nagoya University, Chikusa-ku, Nagoya 464-8601 (Japan); Kusano, K., E-mail: tyamamot@stelab.nagoya-u.ac.jp [Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Kanagawa 236-0001 (Japan)

2012-06-20

230

Nucleon Spin Structure: Longitudinal and Transverse  

SciTech Connect

Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

Jian-Ping Chen

2011-02-01

231

The AQUA-FONTIS study: protocol of a multidisciplinary, cross-sectional and prospective longitudinal study for developing standardized diagnostics and classification of non-thyroidal illness syndrome  

PubMed Central

Background Non-thyroidal illness syndrome (NTIS) is a characteristic functional constellation of thyrotropic feedback control that frequently occurs in critically ill patients. Although this condition is associated with significantly increased morbidity and mortality, there is still controversy on whether NTIS is caused by artefacts, is a form of beneficial adaptation, or is a disorder requiring treatment. Trials investigating substitution therapy of NTIS revealed contradictory results. The comparison of heterogeneous patient cohorts may be the cause for those inconsistencies. Objectives Primary objective of this study is the identification and differentiation of different functional states of thyrotropic feedback control in order to define relevant evaluation criteria for the prognosis of affected patients. Furthermore, we intend to assess the significance of an innovative physiological index approach (SPINA) in differential diagnosis between NTIS and latent (so-called "sub-clinical") thyrotoxicosis. Secondary objective is observation of variables that quantify distinct components of NTIS in the context of independent predictors of evolution, survival or pathophysiological condition and influencing or disturbing factors like medication. Design The approach to a quantitative follow-up of non-thyroidal illness syndrome (AQUA FONTIS study) is designed as both a cross-sectional and prospective longitudinal observation trial in critically ill patients. Patients are observed in at least two evaluation points with consecutive assessments of thyroid status, physiological and clinical data in additional weekly observations up to discharge. A second part of the study investigates the neuropsychological impact of NTIS and medium-term outcomes. The study design incorporates a two-module structure that covers a reduced protocol in form of an observation trial before patients give informed consent. Additional investigations are performed if and after patients agree in participation. Trial Registration ClinicalTrials.gov NCT00591032 PMID:18851740

Dietrich, Johannes W; Stachon, Axel; Antic, Biljana; Klein, Harald H; Hering, Steffen

2008-01-01

232

Shroom, a PDZ Domain–Containing Actin-Binding Protein, Is Required for Neural Tube Morphogenesis in Mice  

Microsoft Academic Search

Using gene trap mutagenesis, we have identified a mutation in mice that causes exencephaly, acrania, facial clefting, and spina bifida, all of which can be attributed to failed neural tube closure. This mutation is designated shroom (shrm) because the neural folds “mushroom” outward and do not converge at the dorsal midline. shrm encodes a PDZ domain protein that is involved

Jeffrey D. Hildebrand; Philippe Soriano

1999-01-01

233

Neural Tube Defects: Review of Experimental Evidence on Stem Cell Therapy and Newer Treatment Options  

Microsoft Academic Search

The failure of closure of the neural tube during development leads to malformations called neural tube defects (NTDs). The most common neural malformations in humans include anencephaly, encephalocele, exencephaly, craniorachischisis spina bifida with or without myelomeningocele, lipomyeloschisis, lipomyelomeningocele, meningocele and myelocystocele. Current preventive strategies are mainly based on pharmacologic\\/folic acid supplementation. However, stem cell-based and other combination approaches may emerge

Dhara B. Dhaulakhandi; Seema Rohilla; Kamal Nain Rattan

2010-01-01

234

Tethered cord syndrome versus low-placed conus medullaris in an over-distended spinal cord following initial repair for myelodysplasia  

Microsoft Academic Search

We present findings obtained from a total of 100 patients who had previously undergone surgery for spina bifida and whose progress had been monitored by magnetic resonance imaging (MRI) in our meningomyelocele clinic. Fourteen of these patients (14.0%) developed delayed symptom(s) of progressive spinal neurologic dysfunction. In those with myeloschisis, increase of motor deficit was the most common clinical manifestation

S. Oi; H. Yamada; S. Matsumoto

1990-01-01

235

Klippel-Feil Syndrome  

MedlinePLUS

... in the normal segmentation or division of the cervical vertebrae during the early weeks of fetal development. The ... spine), spina bifida (a birth defect of the spine), anomalies of the kidneys ... relieve cervical or craniocervical instability and constriction of the spinal ...

236

Roughing It Smoothly.  

ERIC Educational Resources Information Center

A mother of a 17-year-old son with spina bifida recounts the family's experiences camping in the Adirondack Mountains. Her son has enjoyed swimming, modified waterskiing, riding to the top of a mountain during the summer on a ski chair lift, and blueberry picking from a toboggan rather than his wheelchair. (VW)

Turner, Donna

1988-01-01

237

Multiple point action mechanism of valproic acid-teratogenicity alleviated by folic acid, vitamin C, And N-acetylcysteine in chicken embryo model  

Microsoft Academic Search

The teratogenicity of antiepilepsy drug valproic acid (VPA) mostly is found in genetic and somatic levels, causing teratogenesis involving neurotubular defects (NTDs), anencephaly, lumbosacral meningomyelocele, and leg dysfunction due to spina bifida aperta. A diversity of nutraceutics have been tried to alleviate the risk of VPA-teratogenicity. The effect was varying. In order to promote the preventive prescription, to find out

Chiu-Lan Hsieh; Hui-Er Wang; Wan-Jane Tsai; Chiung-Chi Peng; Robert Y. Peng

238

[Enecphalocele: 26 retrospective cases at the Maternal and Neonatal Center of La Rabta, Tunis].  

PubMed

Encephalocel is leff frequent than spina bifida and anencephalia. Its incidence is 0.25@1000 births. It concern as much female than male. This neural defect is frequency associated to others malformations face (20%) squelette (17%), kidney (13%). In our study the ultra sound is performant in 82% of the cases. Encephalocel is still a lethal and severe abnormality. PMID:11332345

Soumaya, S G; Aida, M; Sami, M; Khaled, N; Med Badis, C; Sami, J; Ezedine, S; Zohra, M; Issam, L; Faouzia, Z; Hedi, R; Hela, C; Naima, K

2001-01-01

239

A rare case of thoracic myelocystocele associated with type 1 split cord malformation with low lying tethered cord, dorsal syrinx and sacral agenesis: Pentad finding  

PubMed Central

Myelocystocele is a rare form of spinal dysraphism. Thoracic myelocystocele is still rarer. The occurrence of thoracic myelocystocele associated with type-1 split cord malformation, low lying tethered cord, dorsal syrinx and spina bifida is extremely rare. Clinical presentation of such a rare case and an early surgical management is discussed briefly. PMID:25552859

Mankotia, Dipanker Singh; Satyarthee, Guru Dutta; Sharma, Bhawani Shankar

2015-01-01

240

Swimming for the Handicapped Child and Adult: Occasional Papers No. 10.  

ERIC Educational Resources Information Center

Outlined are physiological and psychological values of swimming for the handicapped, basic principles and teaching procedures for instructing physically handicapped persons, and specific suggestions for teaching swimming to persons with the following conditions; amputations, polio, paraplegia, cerebral palsy, spina bifida, Legg-Perthes Disease,…

Neishloss, Lou

241

38 CFR 17.901 - Provision of health care.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Provision of health care. 17.901 Section 17.901...DEPARTMENT OF VETERANS AFFAIRS MEDICAL Health Care Benefits for Certain Children of...Birth Defects § 17.901 Provision of health care. (a) Spina bifida. VA...

2010-07-01

242

A Case of Enlarged Intracranial Translucency in a Fetus with Blake's Pouch Cyst  

PubMed Central

The intracranial translucency (IT) is a recently introduced marker of open spina bifida (OSB). In this study, we describe a case of a fetus affected by Blake's pouch cyst which showed alterations of BS/BSOB ratio at the first trimester screening. PMID:24523974

Iuculano, Ambra; Zoppi, Maria Angelica; Ibba, Rosa Maria; Monni, Giovanni

2014-01-01

243

Residential agricultural pesticide exposures and risk of neural tube defects and orofacial clefts among offspring in the San Joaquin Valley of California.  

PubMed

We examined whether early gestational exposures to pesticides were associated with an increased risk of anencephaly, spina bifida, cleft lip with or without cleft palate (CLP), or cleft palate only. We used population-based data along with detailed information from maternal interviews. Exposure estimates were based on residential proximity to agricultural pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley, California (1997-2006). Analyses included 73 cases with anencephaly, 123 with spina bifida, 277 with CLP, and 117 with cleft palate only in addition to 785 controls. A total of 38% of the subjects were exposed to 52 chemical groups and 257 specific chemicals. There were relatively few elevated odds ratios with 95% confidence intervals that excluded 1 after adjustment for relevant covariates. Those chemical groups included petroleum derivatives for anencephaly, hydroxybenzonitrile herbicides for spina bifida, and 2,6-dinitroaniline herbicides and dithiocarbamates-methyl isothiocyanate for CLP. The specific chemicals included 2,4-D dimethylamine salt, methomyl, imidacloprid, and ?-(para-nonylphenyl)-?-hydroxypoly(oxyethylene) phosphate ester for anencephaly; the herbicide bromoxynil octanoate for spina bifida; and trifluralin and maneb for CLP. Adjusted odds ratios ranged from 1.6 to 5.1. Given that such odds ratios might have arisen by chance because of the number of comparisons, our study showed a general lack of association between a range of agricultural pesticide exposures and risks of selected birth defects. PMID:24553680

Yang, Wei; Carmichael, Suzan L; Roberts, Eric M; Kegley, Susan E; Padula, Amy M; English, Paul B; Shaw, Gary M

2014-03-15

244

Home Care for Children with Chronic Illnesses and Severe Disabilities: A Bibliography and Resource Guide.  

ERIC Educational Resources Information Center

The bibliography and resource guide summarizes relevant research and information on home care for children with disabilities and chronic illnesses, including those with such diagnoses as spina bifida, cerebral palsy, severe mental retardation, acquired immune deficiency syndrome (AIDS), hemophilia, sickle cell anemia, autism, or failure-to-thrive…

Wells, Alice; And Others

245

Transition to Adult-Oriented Health Care: Perspectives of Youth and Adults with Complex Physical Disabilities  

ERIC Educational Resources Information Center

Introduction: The transition to adulthood is extremely difficult for individuals with disabilities. We sought to explore the specific issue of transition to adult-oriented health care in a Canadian context. Methods: We conducted semi-structured individual interviews with 15 youth and 15 adults with cerebral palsy, spina bifida, and acquired brain…

Young, Nancy L.; Barden, Wendy S.; Mills, Wendy A.; Burke, Tricia A.; Law, Mary; Boydell, Katherine

2009-01-01

246

5 Faculty Review: KARANAS 1) Acute Burn 2) Vertical Breast Reduction followed by Chiefs Lecture  

E-print Network

Plastic Surgery Interview Day 19 Faculty Review: GIROD ­ 1) Oral-Maxillofacial Surgery and Dental Trauma/Press - Spina bifida & Complex Back Reconstruction: Avoiding Complications 2 Faculty Review: KIM - Facial (non-rhino) Cosmetic Surgery 7 9 Faculty Review: LORENZ ­ Craniofacial Anomalies & Cleft Lip and Cleft Palate; Anatomy

Stanford University

247

Kamran Shamaei PhD Candidate in Mechanical Engineering and Materials Science  

E-print Network

on Heat and Fluid, 2004-5 Senior Project: "Determination of Maximum Dynamic Load Carrying Capacity and Prostheses and Biomechanics of Human Gait under Exoskeletal Assistance" Advisor: Prof. Aaron Dollar · Yale: Human subject experiments: Spinal cord injury patients and Spina Bifida patients · Gait laboratory

Haller, Gary L.

248

Folic acid fortification and cancer risk: plea for objective evaluation of the evidence  

Technology Transfer Automated Retrieval System (TEKTRAN)

The letter from Bayston and colleagues,1 representing the Association for Spina Bifida and Hydrocephalus, dismisses concerns raised by two recent studies2, 3 of a possible increase in colorectal cancer (CRC) risk following a high intake of folic acid. In relation to the postulated link between forti...

249

Serum reactivities to latex proteins ( Hevea brasiliensis)  

Microsoft Academic Search

Background: In recent years there has been an increasing incidence of allergy to latex among health care workers and children with spina bifida. The allergic response in these individuals can be severe and occasionally fatal. Several allergens have been identified with the use of sera from different patient groups. In our effort to identify reagents for in vitro testing and

Akira Akasawa; Li-Shan Hsieh; Yuan Lin

1995-01-01

250

Urothlelium Facilitates the Recruitment and TransDifferentiation of Fibroblasts into Smooth Muscle in Acellular Matrix  

Microsoft Academic Search

PurposeTissue engineering has shown promise for patients requiring bladder reconstruction secondary to diverse diseases such as spina bifida and tuberculosis. In this study we addressed whether urothelium in conjunction with an acellular bladder matrix is necessary for the recruitment of host cells to repopulate the graft and whether the urothelium facilitates trans-differentiation of host fibroblastic cells into bladder smooth muscle

VIRAJ A. MASTER; GUANGHUI WEI; WENHUI LIU; LAURENCE S. BASKIN

2003-01-01

251

A longitudinal study of spatial ability.  

PubMed

A number of studies have lent support to the sex-linked major gene theory of spatial ability. Expectations arising from this theory (although not necessarily unique to it) are that spatial ability can be measured in children, that it is the same as spatial ability in adults, and that an individual's position in a distribution of spatial ability remains unchanged over time. Results of a longitudinal experiment utilizing test scores of 76 high school students and their earliertest scores provide confirmatory evidence for these expectations. PMID:1131143

Goldberg, J; Meredith, W

1975-04-01

252

Longitudinal Diagnostics for Short Electron Beam Bunches  

SciTech Connect

Single-pass free electron lasers require high peak currents from ultra-short electron bunches to reach saturation and an accurate measurement of bunch length and longitudinal bunch profile is necessary to control the bunch compression process from low to high beam energy. The various state-of-the-art diagnostics methods from ps to fs time scales using coherent radiation detection, RF deflection, and other techniques are presented. The use of linear accelerators as drivers for free electron lasers (FEL) and the advent of single-pass (SASE) FELs has driven the development of a wide range of diagnostic techniques for measuring the length and longitudinal distribution of short and ultra-short electron bunches. For SASE FELs the radiation power and the length of the undulator needed to achieve saturation depend strongly on the charge density of the electron beam. In the case of X-ray FELs, this requires the accelerator to produce ultra-high brightness beams with micron size transverse normalized emittances and peak currents of several kA through several stages of magnetic bunch compression. Different longitudinal diagnostics are employed to measure the peak current and bunch profile along these stages. The measurement techniques can be distinguished into different classes. Coherent methods detect the light emitted from the beam by some coherent radiation process (spectroscopic measurement), or directly measure the Coulomb field traveling with the beam (electro-optic). Phase space manipulation techniques map the time coordinate onto a transverse dimension and then use conventional transverse beam diagnostics (transverse deflector, rf zero-phasing). Further methods measure the profile or duration of an incoherent light pulse emitted by the bunch at wavelengths much shorted than the bunch length (streak camera, fluctuation technique) or modulate the electron beam at an optical wavelength and then generate a narrow bandwidth radiation pulse with the longitudinal profile of the beam mapped onto (optical replicator). The operational needs for bunch length measurements to have fast acquisitions, to be used in feedback systems, to distinguish pulse to pulse changes and to be nondestructive or parasitically have resulted into developing many of the diagnostics into single-shot techniques and in the following the main discussion will emphasize them.

Loos, H.; /SLAC; ,

2010-06-11

253

Parametric survey of longitudinal prominence oscillation simulations  

NASA Astrophysics Data System (ADS)

Context. Longitudinal filament oscillations recently attracted increasing attention, while the restoring force and the damping mechanisms are still elusive. Aims: We intend to investigate the underlying physics for coherent longitudinal oscillations of the entire filament body, including their triggering mechanism, dominant restoring force, and damping mechanisms. Methods: With the MPI-AMRVAC code, we carried out radiative hydrodynamic numerical simulations of the longitudinal prominence oscillations. We modeled two types of perturbations of the prominence, impulsive heating at one leg of the loop and an impulsive momentum deposition, which cause the prominence to oscillate. We studied the resulting oscillations for a large parameter scan, including the chromospheric heating duration, initial velocity of the prominence, and field line geometry. Results: We found that both microflare-sized impulsive heating at one leg of the loop and a suddenly imposed velocity perturbation can propel the prominence to oscillate along the magnetic dip. Our extensive parameter survey resulted in a scaling law that shows that the period of the oscillation, which weakly depends on the length and height of the prominence and on the amplitude of the perturbations, scales with ?R/g?, where R represents the curvature radius of the dip, and g? is the gravitational acceleration of the Sun. This is consistent with the linear theory of a pendulum, which implies that the field-aligned component of gravity is the main restoring force for the prominence longitudinal oscillations, as confirmed by the force analysis. However, the gas pressure gradient becomes significant for short prominences. The oscillation damps with time in the presence of non-adiabatic processes. Radiative cooling is the dominant factor leading to damping. A scaling law for the damping timescale is derived, i.e., ?~ l1.63 D0.66w-1.21v0-0.30, showing strong dependence on the prominence length l, the geometry of the magnetic dip (characterized by the depth D and the width w), and the velocity perturbation amplitude v0. The larger the amplitude, the faster the oscillation damps. We also found that mass drainage significantly reduces the damping timescale when the perturbation is too strong.

Zhang, Q. M.; Chen, P. F.; Xia, C.; Keppens, R.; Ji, H. S.

2013-06-01

254

Resonant longitudinal Zitterbewegung in zigzag graphene nanoribbons  

NASA Astrophysics Data System (ADS)

The Zitterbewegung of a wave packet in a zigzag graphene nanoribbon is theoretically investigated. The coupling between edge states and bulk states results in intriguing properties. Apart from the oscillation in position perpendicular to the direction of motion, we also observe an oscillation along the direction of propagation which is not present in semiconductor nanowires or infinite graphene sheets. We also observe a resonance of its amplitude with respect to the central momentum of the wave packet. We show here that this longitudinal Zitterbewegung is caused by the interplay between bulk and edge states, which is a unique property of a zigzag nanoribbon.

Ghosh, S.; Schwingenschlögl, U.; Manchon, A.

2015-01-01

255

Apparatus for demonstrating longitudinal wave pulses  

NASA Astrophysics Data System (ADS)

For live classroom demonstrations there are a number of devices that have been used to simulate waves. Some are based upon a design produced by E. S. Ritchie & Sons and consist of rods and cams that are activated by turning a crank.2,3 These devices show what transverse and longitudinal waves look like, but they do not allow for the free manipulation of wave parameters and observations of the changes that take place. A simple device can be constructed using elastic bands and straws4 to demonstrate properties of transverse waves.

Trikosko, Walter L.; Callaway, Thomas O.

2011-05-01

256

Longitudinal feedback system kicker for the PLS storage ring  

Microsoft Academic Search

The higher order modes (HOMs) of RF cavities at the Pohang Light Source (PLS) storage ring cause longitudinal coupled bunch mode instabilities. A longitudinal feedback system (LFS) is introduced to cure these instabilities. As a key component of the LFS, there is a single-ridged waveguide-overloaded cavity for a longitudinal bunch-by-bunch LFS kicker. Since the RF frequency is 500 MHz, the

Yujong Kim; M. Kwon; J. Y. Huang; W. Namkung; I. S. Ko

2000-01-01

257

Longitudinally pumped pulsed Ti:S laser  

NASA Astrophysics Data System (ADS)

Our pulsed Ti:S laser is abaxial longitudinally pumped by a frequency double YAG laser with VRM unstable resonator, the Ti:S crystal is Bi-Brewster-cutting. The single output energy of the Ti:S laser is over 130 mJ at 1 Hz and over 110 mJ at 10 Hz, the efficiency is 39.6% and 36. 7% respectively, the tunable range is 0.723 approximately 0.996 micrometers with only a pair of flat mirrors, the output energy in the two ends is 1/10 of that in the center wavelength. We discuss the effect of choice of the crystal size, the angle (alpha) (between the pump beam and the cavity axis) on efficiency. We suggest that the high absorptivity, high FOM value of the crystal bring high output and high efficiency when longitudinally pumped by a flat-top laser beam. We also show the scheme of our Ti:S laser and our broad band transmitted curve of reflective mirror.

Liu, Hongfa; Yan, Baisheng; Lei, Hairong; Zhang, Guowei; Chen, Qinghan

1996-09-01

258

Longitudinally pumped pulsed Ti:S laser  

SciTech Connect

The pulsed Ti:S laser is abaxial longitudinally pumped by a frequency doubled YAG laser with VRM unstable resonator. The single output energy of the Ti:S laser is over 130mJ at 1Hz and over 110mJ at 10Hz, the efficiency is 39.6% and 36.7% respectively, the tunable range is 0.723 {approximately} 0.996 {micro}m with only a pair of flat mirrors, the output energy in the two ends is 1/10 of that in the center wavelength. The authors discuss the effect of choice of the crystal size, the angle {alpha} (between the pump beam and the cavity axis) on efficiency. They suggest that the high absorptivity, high FOM value of the crystal bring high output and high efficiency when longitudinally pumped by a flat-top laser beam. They also show the scheme of their Ti:S laser and the broad band transmitted curve of reflective mirror.

Liu Hongfa; Yan Baisheng; Lei Hairong; Zhang Guowei [Beijing Inst. of Tech. (China). Dept. of Optical Engineering; Chen, Qinghan [Southwest Inst. of Technical Physics, Chengdu (China)

1996-12-31

259

LONGITUDINAL IMPEDANCE OF THE SQUID GIANT AXON  

PubMed Central

Longitudinal alternating current impedance measurements have been made on the squid giant axon over the frequency range from 30 cycles per second to 200 kc. per second. Large sea water electrodes were used and the inter-electrode length was immersed in oil. The impedance at high frequency was approximately as predicted theoretically on the basis of the poorly conducting dielectric characteristics of the membrane previously determined. For the large majority of the axons, the impedance reached a maximum at a low frequency and the reactance then vanished at a frequency between 150 and 300 cycles per second. Below this frequency, the reactance was inductive, reaching a maximum and then approaching zero as the frequency was decreased. The inductive reactance is a property of the axon and requires that it contain an inductive structure. The variation of the impedance with interpolar distance indicates that the inductance is in the membrane. The impedance characteristics of the membrane as calculated from the measured longitudinal impedance of the axon may be expressed by an equivalent membrane circuit containing inductance, capacity, and resistance. For a square centimeter of membrane the capacity of 1 µf with dielectric loss is shunted by the series combination of a resistance of 400 ohms and an inductance of one-fifth henry. PMID:19873252

Cole, Kenneth S.; Baker, Richard F.

1941-01-01

260

Parental mediation and cyberbullying - a longitudinal study.  

PubMed

Parents use active and restrictive mediation strategies to guide and regulate children's online participation and the online risks they encounter. However, changes in parental mediation do occur over time and the effectiveness of these strategies on cyberbullying demands for further empirical investigation. The current study addresses these issues with a sample of 1084 students (49% girls) in a longitudinal, three-wave design. Gender differences were tested via multi-group analyses. Longitudinal growth models showed that parental use of both active and restrictive mediation decreased over time. For both types of mediation, the mean rate of change had a significant effect on boys' engagement in cyberbullying, but not for girls. Initial levels of restrictive mediation, but not active mediation, were found to be significantly predictive of cyberbullying in both genders. Girls had higher initial levels of both parental mediation types in comparison to boys. The results reveal that the effectiveness of active and restrictive mediation in relation to students' cyberbullying differs and informs us on gender differences. The implications of these results for parental education in online mediation are discussed. PMID:24875699

Chng, Grace S; Liau, Albert; Khoo, Angeline; Li, Dongdong

2014-01-01

261

Longitudinal seam weld characterization by focused ultrasonics  

NASA Astrophysics Data System (ADS)

Increasingly, the detectability limits placed on inspection methodologies applied to the assessment of critical high energy components in fossil fuelled power plants are being forced to lower values. Most notably, recent events involving longitudinal seam welded piping have raised the question of lowering the detectibility limit for ultrasonics to a level necessary for resolving incipient creep damage. Historically, several testing methods were required for the detection of defects over the range of anticipated flaw sizes in an economically and technically acceptable manner. However, unyielding limitations exist for several of these currently used methods. While accepting that the detection of isolated creep cavities is not technically feasible with current conventional ultrasonic methods, the detection of high density cavitation sheets or zones prior to microcrack initiation has been demonstrated and successfully applied to field inspection of critical welds using focused ultrasonics. This paper describes the equipment and verification process used to extend the detectability limit of a field ultrasonic systems for longitudinal seam weld evaluations to approaching that of an acoustic microscope for the identification of incipient creep cavitation.

Bisbee, Laney H.; Nottingham, Lawrence

1996-11-01

262

Longitudinal effects of PTSD on memory functioning.  

PubMed

Numerous studies have demonstrated explicit and working memory deficits related to posttraumatic stress disorder (PTSD), but few have addressed longitudinal changes in memory functioning. There is some evidence to suggest an interactive effect of PTSD and aging on verbal memory decline in Holocaust survivors (Yehuda et al., 2006). However, the longitudinal trajectory of neuropsychological functioning has not been investigated in Vietnam veterans, a younger but substantial population of aging trauma survivors. We administered tests of visual and verbal memory, and working memory to derive different dependent measures in veterans between the ages of 41 and 63, the majority of whom served in the Vietnam War. Twenty-five veterans with PTSD and 22 veterans without PTSD were assessed over two time points (mean age at follow-up = 54.0; mean inter-test interval = 34 months). The PTSD+ group, consisting of veterans with chronic, primarily combat-related PTSD, did not show a significant change in PTSD symptoms over time. Compared to veterans without PTSD, veterans with PTSD showed a greater decline in delayed facial recognition only, and this decline was extremely subtle. PMID:19703319

Samuelson, Kristin W; Neylan, Thomas C; Lenoci, Maryanne; Metzler, Thomas J; Cardenas, Valerie; Weiner, Michael W; Marmar, Charles R

2009-11-01

263

A longitudinal study of urea cycle disorders.  

PubMed

The Urea Cycle Disorders Consortium (UCDC) is a member of the NIH funded Rare Diseases Clinical Research Network and is performing a longitudinal study of 8 urea cycle disorders (UCDs) with initial enrollment beginning in 2006. The consortium consists of 14 sites in the U.S., Canada and Europe. This report summarizes data mining studies of 614 patients with UCDs enrolled in the UCDC's longitudinal study protocol. The most common disorder is ornithine transcarbamylase deficiency, accounting for more than half of the participants. We calculated the overall prevalence of urea cycle disorders to be 1/35,000, with 2/3rds presenting initial symptoms after the newborn period. We found the mortality rate to be 24% in neonatal onset cases and 11% in late onset cases. The most common precipitant of clinical hyperammonemic episodes in the post-neonatal period was intercurrent infections. Elevations in both blood ammonia and glutamine appeared to be biomarkers for neurocognitive outcome. In terms of chronic treatment, low protein diet appeared to result in normal weight but decreased linear growth while N-scavenger therapy with phenylbutyrate resulted in low levels of branched chain amino acids. Finally, we found an unexpectedly high risk for hepatic dysfunction in patients with ornithine transcarbamylase deficiency. This natural history study illustrates how a collaborative study of a rare genetic disorder can result in an improved understanding of morbidity and disease outcome. PMID:25135652

Batshaw, Mark L; Tuchman, Mendel; Summar, Marshall; Seminara, Jennifer

2014-01-01

264

Transversal and longitudinal mixing in compound channels  

NASA Astrophysics Data System (ADS)

An experimental campaign, based on particle image velocimetry (PIV) measurements of free-surface velocities, forms the basis for an analysis of the mixing processes which occur in a compound-channel flow. The flow mixing is characterized in terms of Lagrangian statistics (absolute dispersion and diffusivity) and of the related mean flow characteristics. Mixing properties strongly depend on the ratiorh between the main channel flow depth (h*mc) and the floodplain depth (h*fp), and three flow classes can be identified, namely shallow, intermediate, and deep flows. In the present study the large time asymptotic behavior of the mixing characteristics is analyzed in terms of the absolute diffusivity in order to characterize typical values of longitudinal and transversal diffusivity coefficients. Various sets of experiments, which cover a wide range of the governing physical parameters, have been performed and the asymptotic values of the absolute diffusivity have been evaluated. The results are then compared with several studies of flow dispersion for both the longitudinal diffusivity coefficient and the transversal turbulent mixing coefficient. The present results highlight a stronger dependence of such coefficients with the flow-depth ratio than with the flow regime (Froude number).

Besio, G.; Stocchino, A.; Angiolani, S.; Brocchini, M.

2012-12-01

265

Entanglement from Longitudinal and Scalar Photons  

NASA Astrophysics Data System (ADS)

The covariant quantization of the electromagnetic field in the Lorentz gauge gives rise to longitudinal and scalar photons in addition to the usual transverse photons [1]. This is necessary because the vector and scalar potentials form the components of a four-vector. Quantizing only the transverse components of the field would give different results in different reference frames and is not invariant under Lorentz transformations. Here we calculate the entanglement of two atoms or harmonic oscillators due to the exchange of longitudinal and scalar photons. The form of the entangled state is found to be very different from that obtained using only transverse photons in the Coulomb gauge. Nevertheless, a generalized gauge transformation is used to show that the results are physically equivalent. A covariant treatment of photons is necessary for a fundamental understanding of quantum optics and it may have practical implications for quantum communications between satellites and ground stations, for example. [4pt] [1] For example, see C. Cohen-Tannoudji, J. Dupont-Roc, and G. Grynberg, Photons and Atoms (Wiley, New York, 1989.)

Franson, James

2011-06-01

266

Longitudinal Muscle Dysfunction in Achalasia Esophagus and Its Relevance  

PubMed Central

Muscularis propria of the esophagus is organized into circular and longitudinal muscle layers. Goal of this review is to summarize the role of longitudinal muscle in physiology and pathophysiology of esophageal sensory and motor function. Simultaneous manometry and ultrasound imaging that measure circular and longitudinal muscle contraction respectively reveal that during peristalsis 2 layers of the esophagus contract in perfect synchrony. On the other hand, during transient relaxation of the lower esophageal sphincter (LES), longitudinal muscle contracts independently of circular muscle. Recent studies provide novel insights, i.e., longitudinal muscle contraction of the esophagus induces LES relaxation and possibly descending relaxation of the esophagus. In achalasia esophagus and other motility disorders there is discoordination between the 2 muscle layers. Longitudinal muscle contraction patterns are different in the recently described three types of achalasia identified by high-resolution manometry. Robust contraction of the longitudinal muscle in type II achalasia causes pan-esophageal pressurization and is the mechanism of whatever little esophageal emptying that take place in the absence of peristalsis and impaired LES relaxation. It may be that preserved longitudinal muscle contraction is also the reason for superior outcome to medical/surgical therapy in type II achalasia esophagus. Prolonged contractions of longitudinal muscles of the esophagus is a possible mechanism of heartburn and "angina like" pain seen in esophageal motility disorders and possibly achalasia esophagus. Novel techniques to record longitudinal muscle contraction are on the horizon. Neuro-pharmacologic control of circular and longitudinal muscles is different, which provides an important opportunity for the development of novel pharmacological therapies to treat sensory and motor disorders of the esophagus. PMID:23667744

Hong, Su Jin; Bhargava, Valmik

2013-01-01

267

Beam Tomography in Longitudinal Phase Space  

NASA Astrophysics Data System (ADS)

Longitudinal particle motion in circular accelerators is typically monitored by one dimensional (1-D) profiles. Adiabatic particle motion in 2-D phase space can be reconstructed with tomographic techniques, using 1-D profiles. In this paper, we discuss a filtered backprojection algorithm, with a high pass ramp or Hann filter, for phase space reconstruction. The algorithm uses several projections of the beam at equally spaced angles over half a synchrotron period. A computer program RADON has been developed to process digitized mountain range data and do the phase space reconstruction for the AGS, and later for Relativistic Heavy Ion Collider (RHIC). Analysis has been performed to determine the sensitivity to machine parameters and data acquisition errors. During the Sextant test of RHIC in early 1997, this program has been successfully employed to reconstruct the motion of Au^77+ beam in the AGS.

Mane, V.; Wei, J.; Peggs, S.

1997-05-01

268

Latitudinal and longitudinal barriers in global biogeography  

PubMed Central

Due to changes in climate and continental arrangement, plant and animal assemblages faced different dispersal barriers at different moments in Earth's history. It is generally accepted that groups which diversified during times of Gondwanan–Laurasian separation show different distribution patterns from those of more recent origin. Here I present principal component-derived maps for two globally distributed groups, with ca 1000 species each. Gymnosperm assemblages perfectly illustrate the existence of southern and northern components, corresponding to the Gondwanan and Laurasian temperate floras at the time when angiosperms started becoming dominant in the tropics, thus imposing a latitudinal barrier. Bat (chiropteran) assemblages indicate that the major biogeographical barrier in their Cenozoic dispersal was the longitudinal separation between the Old and New World. PMID:17148329

Proche?, ?erban

2005-01-01

269

Longitudinal Changes in Cognitive Functioning in Adult Day Care Participants  

Microsoft Academic Search

This study examines longitudinal changes in cognitive functioning over the course of 2 years in participants of adult day care programs. Cognitive measures included the Brief Cognitive Rating Scale (BCRS) and the Mini-Mental State Examination (MMSE). Longitudinal data were available for five measurement points over 2 years for 82 participants (22 males and 60 females). Overall, results from this study

Jiska Cohen-Mansfield; Ann L. Gruber-Baldini; William J. Culpepper; Perla Werner

1996-01-01

270

Longitudinally slotted conical horn antenna with small flare angle  

Microsoft Academic Search

The radiation and cross polarization characteristics of a longitudinally slotted, conical horn antenna with small flare angle, excited in the modified TE(11) mode, are investigated. To this end the electromagnetic wave propagation in a longitudinally slotted circular waveguide is studied first, using a wall reactance model. Because of the need to introduce mode-dependent wall reactances in the present structure, conditions

T. Scharten; J. Nellen; F. van den Bogaart

1981-01-01

271

Longitudinal Research with Sexual Assault Survivors: A Methodological Review  

ERIC Educational Resources Information Center

Longitudinal research designs are relatively rare in the academic literature on rape and sexual assault despite their tremendous methodological rigor and scientific utility. In the interest of promoting wider use of such methods, we conducted a methodological review of projects that have used prospective longitudinal designs to study the…

Campbell, Rebecca; Sprague, Heather Brown; Cottrill, Sara; Sullivan, Cris M.

2011-01-01

272

Reflex vertical gaze and the medial longitudinal fasciculus  

Microsoft Academic Search

Extraocular movements were investigated in a patient with bilateral vascular lesions of the medial longitudinal fasciculus. The patient showed voluntary and reflex horizontal gaze consistent with his lesion, but had absent reflex vertical gaze. Voluntary vertical gaze was present. Necropsy was performed, and the findings suggest that the medial longitudinal fasciculi in the pons conveys impulses for reflex vertical gaze,

L. R. Jenkyn; G. Margolis; A. G. Reeves

1978-01-01

273

Longitudinal analyses of religious and spiritual development among seminary students  

Microsoft Academic Search

We conducted a longitudinal study of spiritual development among a sample of graduate-level seminary students (N = 119) at a religiously affiliated university in the Midwest. Seven longitudinal hypotheses were tested based on a relational model of spirituality (Shults & Sandage, 2006). Over time, we expected that the seminary context would facilitate increases in students’ questing, intrinsic religiosity, spiritual well-being,

Ian Todd Williamson; Steven J. Sandage

2009-01-01

274

The modified electromagnetism and the emergent longitudinal wave  

E-print Network

The classical theory of electromagnetism has been revisited and the possibility of longitudinal photon wave is explored. It is shown that the emergence of longitudinal wave is a consequence of Lorenz gauge (condition) violation. Proca, Vlaenderen & Waser and Arbab theories are investigated.

Arbab I Arbab; Mudhahir Al-Ajmi

2014-01-22

275

46 CFR 172.095 - Intact longitudinal stability.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping...SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO BULK CARGOES...Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

2013-10-01

276

46 CFR 172.095 - Intact longitudinal stability.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping...SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO BULK CARGOES...Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

2012-10-01

277

46 CFR 172.095 - Intact longitudinal stability.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping...SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO BULK CARGOES...Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

2011-10-01

278

46 CFR 172.095 - Intact longitudinal stability.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Intact longitudinal stability. 172.095 Section 172.095 Shipping...SECURITY (CONTINUED) SUBDIVISION AND STABILITY SPECIAL RULES PERTAINING TO BULK CARGOES...Chapter § 172.095 Intact longitudinal stability. Each tank barge must be...

2014-10-01

279

Longitudinal Trajectories of Perceived Body Weight: Adolescence to Early Adulthood  

ERIC Educational Resources Information Center

Objective: To examine longitudinal trajectories of perceived weight from adolescence to early adulthood by gender. Methods: We analyzed 9 waves (1997-2005) of data from the National Longitudinal Survey of Youth (N = 8302) using Mplus. Results: Perceived overweight increased over time among girls and did not level off until 23 years of age. Blacks…

Seo, Dong-Chul; Li, Kaigang

2012-01-01

280

A Longitudinal Study of Adolescent Adjustment Following Family Transitions  

ERIC Educational Resources Information Center

Background: This study examined the impact of family transitions, that is, parental separation, divorce, remarriage and death, upon the lives of Australian children and adolescents in a longitudinal study of temperament and development. Methods: Using longitudinal and concurrent questionnaire data, outcomes for young people experiencing…

Ruschena, Eda; Prior, Margot; Sanson, Ann; Smart, Diana

2005-01-01

281

Learning from Longitudinal Research in Criminology and the Health Sciences  

ERIC Educational Resources Information Center

This article reviews longitudinal research within criminology and the health sciences on the relationship between reading and criminal, delinquent, or antisocial behavior. Longitudinal research in criminology, medicine, and psychology examines the role of reading within a broad set of interactive processes, connecting literacy to public health via…

Vanderstaay, Steven L.

2006-01-01

282

Generalized Linear Models with Longitudinal Covariates Daowen Zhang  

E-print Network

; Asymptotic Relative EÃ?ciency; Mixed models; Repeated measurements. Running title: \\GLMs with Longitudinal covariates. We assume the lon- gitudinal covariates follow a linear mixed model and the primary outcome measure of the longitudinal covariate when #12;tting a generalized linear model. Alternatively, some

Zhang, Daowen

283

IMPUTATION METHODS ON GENERAL LINEAR MIXED MODELS OF LONGITUDINAL STUDIES  

Microsoft Academic Search

Survey data collection is a very efficient way to gather information for research of interest. Many state and federal government agencies collect data through surveys. Long-term longitudinal studies are the most appropriate studies for the study of individual change over time. As a result, most longitudinal studies and surveys have non-responses and missing data issues. The problem of missing data

YANN-YANN SHIEH

284

Formulating mixed models for experiments, including longitudinal experiments  

E-print Network

Formulating mixed models for experiments, including longitudinal experiments C. J. Brien1 and C of experiments, particularly those that require more complicated models (e.g. those that involve longitudinal data). This article describes a method for deriving the terms in a mixed model. Our approach extends

Brien, Chris

285

An analytical model of a longitudinal-torsional ultrasonic transducer  

Microsoft Academic Search

The combination of longitudinal and torsional (LT) vibrations at high frequencies finds many applications such as ultrasonic drilling, ultrasonic welding, and ultrasonic motors. The LT mode can be obtained by modifications to the design of a standard bolted Langevin ultrasonic transducer driven by an axially poled piezoceramic stack, by a technique that degenerates the longitudinal mode to an LT motion

Hassan Al-Budairi; Margaret Lucas

2012-01-01

286

A Cautionary Note on Modeling Growth Trends in Longitudinal Data  

ERIC Educational Resources Information Center

Random coefficient and latent growth curve modeling are currently the dominant approaches to the analysis of longitudinal data in psychology. The application of these models to longitudinal data assumes that the data-generating mechanism behind the psychological process under investigation contains only a deterministic trend. However, if a…

Kuljanin, Goran; Braun, Michael T.; DeShon, Richard P.

2011-01-01

287

Future Orientation, Impulsivity, and Problem Behaviors: A Longitudinal Moderation Model  

ERIC Educational Resources Information Center

In the current study, based on a sample of 1,873 adolescents between 11.4 and 20.9 years of age from the first 3 waves of the National Longitudinal Study of Adolescent Health, we investigated the longitudinal effects of future orientation on levels of and developmental changes in problem behaviors, while controlling for the effects by impulsivity;…

Chen, Pan; Vazsonyi, Alexander T.

2011-01-01

288

TAILOR THE LONGITUDINAL ANAYSIS FOR NIH LONGITUDINAL NORMAL BRAIN DEVELOPMENTAL STUDY  

PubMed Central

There are imminent needs for longitudinal analysis to make physiological inferences on NIH MRI study of normal brain development. But up to date, two critical aspects for longitudinal analysis, namely the selections of mean and covariance structures have not been addressed by the neuroimaging community. For the mean structure, we employed a linear free-knot B-spline regression in combination with quasi-least square estimating equations to approximate a nonlinear growth trajectory with piecewise linear segments for a friendly physiological interpretation. For covariance structure selection, we have proposed a novel time varying correlation structure considering not only the time separation between the repeated measures but also when these acquisitions occurred. We have demonstrated that the proposed covariance structure has a lower Akaike information criterion value than the commonly used Markov correlation structure. PMID:25405003

Chen, Yasheng; An, Hongyu; Shen, Dinggang; Zhu, Hongtu; Lin, Weili

2014-01-01

289

Enhanced magnetoelectric effect in longitudinal-longitudinal mode laminate with cofired interdigitated electrodes  

NASA Astrophysics Data System (ADS)

In this letter, we describe a low-temperature cofiring technique to embed the interdigitated electrodes (IDE) inside the piezoelectric ceramic layer to achieve longitudinally (L) poled magnetoelectric (ME) laminates. The ME voltage coefficient of this L-L mode composite was found to be 4.41 V cm-1 Oe-1 at 1 kHz, which is 340% higher than that of L-T (transversal) mode. IDE based longitudinal poling and piezoelectric response was evaluated by impedance changes and piezoresponse force microscopy, illustrating the effect of inactive/ineffective zone in the range beneath and above the fingers with vanishing fields. At an electric field of 50 V/cm, the composite was found to generate magnetic field on the order of 175 ?G at 1 kHz.

Yan, Yongke; Zhou, Yuan; Priya, Shashank

2014-01-01

290

Delay of left ventricular longitudinal expansion with diastolic dysfunction: impact on load dependence of e' and longitudinal strain rate.  

PubMed

The effect of diastolic dysfunction (DD) on the timing of left ventricular (LV) diastolic longitudinal and circumferential expansion and their load dependence is not known. This study evaluated the timing of the peak early diastolic LV inflow velocity (E), mitral annular velocity (e'), and longitudinal and circumferential global strain rates (SRE) in 161 patients in sinus rhythm. The intraventricular pressure difference (IVPD) from the left atrium to the LV apex was obtained using color M-mode Doppler data to integrate the Euler equation. The diastolic function was graded according to the guidelines. In normals (N = 57), E, e', longitudinal SRE, and circumferential SRE occurred nearly simultaneously during the IVPD. With DD (N = 104), e' and longitudinal SRE were delayed occurring after the IVPD (e': 18 ± 23 msec, longitudinal SRE: 13 ± 21 msec from the IVPD), whereas circumferential SRE (-8 ± 28 msec) and E (-2 ± 13 msec) were not delayed. The normal dependence of e' and longitudinal SRE on IVPD was reduced in DD; while the relation of circumferential SRE and E to IVPD were unchanged in DD. Thus, normally, the LV expands symmetrically during early diastole and both longitudinal and circumferential expansions are related to the IVPD. With DD, early diastolic longitudinal LV expansion is delayed, occurring after the IVPD and LV filling, resulting in their relative independence from the IVPD. In contrast, with DD, circumferential SRE and mitral inflow are not delayed and their normal relation to the IVPD is unchanged. PMID:25035279

Iwano, Hiroyuki; Pu, Min; Upadhya, Bharathi; Meyers, Brett; Vlachos, Pavlos; Little, William C

2014-07-01

291

Vertical longitudinal magnetoresistance of semiconductor superlattices Yu. A. Pusep,1,2  

E-print Network

Vertical longitudinal magnetoresistance of semiconductor superlattices Yu. A. Pusep,1,2 G. M. Gusev manuscript received 19 January 2001; published 2 April 2001 Vertical longitudinal magnetoresistance VLMR the surface conductiv- ity contributes significantly. Moreover, the vertical longitudinal magnetoresistance

Gusev, Guennady

292

76 FR 58252 - Applications for New Awards; Statewide, Longitudinal Data Systems Program  

Federal Register 2010, 2011, 2012, 2013, 2014

...Applications for New Awards; Statewide, Longitudinal Data Systems Program AGENCY...Longitudinal Data Systems Program. Notice...applications for new awards for fiscal year...Longitudinal Data Systems program awards grants to State...

2011-09-20

293

Longitudinal determinants of substance use disorders.  

PubMed

Substance use and substance use disorders (SUDs) have been linked with marital discord. Relatively little is known, however, about the antecedents of SUDs, the mediators of these factors over time, or their associations with the spousal/partner relationship among urban adults. A better understanding of the longitudinal pathways to marital conflict and to SUDs should help prevention and intervention programs target their precursors within the developmental period in which they occur. The present study, therefore, examined the longitudinal predictors of an unsupportive spousal/partner relationship and SUDs among a community sample of urban African American and Puerto Rican adults from East Harlem, NY. Participants (N?=?816) completed structured questionnaires at five time waves, from adolescence to adulthood (mean ages?=?14, 19, 24, 29, and 32 years). Structural equation modeling examined the effects of earlier environmental and social stressors and intrapersonal and interpersonal factors on later SUDs in adulthood. There was a good fit of the structural equation model (CFI?=?0.91; RMSEA?=?0.06; and SRMR?=?0.06), which revealed three main pathways from adolescence to the spousal/partner relationship and SUDs in adulthood. One pathway linked a weak parent-adolescent attachment relationship with the participant's psychological symptoms in emerging adulthood (p?

Brook, Judith S; Lee, Jung Yeon; Rubenstone, Elizabeth; Finch, Stephen J; Seltzer, Nathan; Brook, David W

2013-12-01

294

Occupational exposures and longitudinal lung function decline.  

PubMed

Background Few longitudinal studies have been conducted on occupational exposure and lung function. This study investigated occupational dust exposure effects on lung function and whether genetic variants influence such effects. Methods The study population (1,332 participants) was from the Framingham Heart Study, in which participant lung function measures were available from up to five examinations over nearly 17 years. Occupational dust exposures were classified into "more" and "less" likely dust exposure. We used linear mixed effects models for the analysis. Results Participants with more likely dust exposure had a mean 4.5?mL/year excess loss rate of FEV1 over time. However, occupational dust exposures alone or interactions with age or time had no significant effect on FEV1 /FVC. No statistically significant effects of genetic modifications in the different subgroups were identified for FEV1 loss. Conclusions Occupational dust exposures may accelerate the rate of FEV1 loss but not FEV1 /FVC loss. Am. J. Ind. Med. 58:14-20, 2015. © 2014 Wiley Periodicals, Inc. PMID:25384732

Liao, Shu-Yi; Lin, Xihong; Christiani, David C

2015-01-01

295

Parametric survey of longitudinal prominence oscillation simulations  

E-print Network

It is found that both microflare-sized impulsive heating at one leg of the loop and a suddenly imposed velocity perturbation can propel the prominence to oscillate along the magnetic dip. An extensive parameter survey results in a scaling law, showing that the period of the oscillation, which weakly depends on the length and height of the prominence, and the amplitude of the perturbations, scales with $\\sqrt{R/g_\\odot}$, where $R$ represents the curvature radius of the dip, and $g_\\odot$ is the gravitational acceleration of the Sun. This is consistent with the linear theory of a pendulum, which implies that the field-aligned component of gravity is the main restoring force for the prominence longitudinal oscillations, as confirmed by the force analysis. However, the gas pressure gradient becomes non-negligible for short prominences. The oscillation damps with time in the presence of non-adiabatic processes. Compared to heat conduction, the radiative cooling is the dominant factor leading to the damping. A sca...

Zhang, Q M; Xia, C; Keppens, R; Ji, H S

2013-01-01

296

Longitudinal dynamic stability of a shuttle vehicle.  

NASA Technical Reports Server (NTRS)

Analytical study of the longitudinal dynamic stability of a nonrolling, lifting vehicle gliding at hypersonic speeds. The analysis applies to shuttle vehicles designed for operating up to the rim of a planetary atmosphere. A general nondimensional time transformation is introduced to derive a unified second-order linear differential equation for the angle of attack, valid for all types of reentry of a general type of vehicle. The stability of motion is discussed for two fundamental regimes of flight that are based on widely different assumptions. For near ballistic entry along a straight line trajectory, the equation reduces to a confluent hypergeometric equation, the solution of which can be expressed in terms of Whittaker's function. Using a theorem in the theory of stability of differential equations, criteria for damped oscillations are derived. It is shown that the aerodynamic criteria for stability are the same as for the case of ballistic entry. In addition, for each vehicle configuration, and specified planetary atmosphere, there exists an altitude range where the angle of attack frequency is nearly equal to the orbital frequency causing instability in pitch. This resonance instability is due to the ellipticity of the orbit. Criteria for eccentricity instability are derived.

Vinh, N. X.; Laitone, E. V.

1972-01-01

297

Dual imputation model for incomplete longitudinal data.  

PubMed

Missing values are a practical issue in the analysis of longitudinal data. Multiple imputation (MI) is a well-known likelihood-based method that has optimal properties in terms of efficiency and consistency if the imputation model is correctly specified. Doubly robust (DR) weighing-based methods protect against misspecification bias if one of the models, but not necessarily both, for the data or the mechanism leading to missing data is correct. We propose a new imputation method that captures the simplicity of MI and protection from the DR method. This method integrates MI and DR to protect against misspecification of the imputation model under a missing at random assumption. Our method avoids analytical complications of missing data particularly in multivariate settings, and is easy to implement in standard statistical packages. Moreover, the proposed method works very well with an intermittent pattern of missingness when other DR methods can not be used. Simulation experiments show that the proposed approach achieves improved performance when one of the models is correct. The method is applied to data from the fireworks disaster study, a randomized clinical trial comparing therapies in disaster-exposed children. We conclude that the new method increases the robustness of imputations. PMID:23909566

Jolani, Shahab; Frank, Laurence E; van Buuren, Stef

2014-05-01

298

A longitudinal analysis of nursing home outcomes.  

PubMed Central

OBJECTIVE: To investigate resident and facility attributes associated with long-term care health outcomes in nursing homes. DATA SOURCES: Quarterly Management Minutes Questionnaire (MMQ) survey data for Medicaid case-mix reimbursement of nursing homes in Massachusetts from 1991 to 1994, for specification of outcomes and resident attributes. Facility attributes are specified from cost report data. STUDY DESIGN: Multivariate logistic and "state-dependence" regression models are estimated for survival, ADL functional status, incontinence status, and mental status outcomes from longitudinal residence histories of Medicaid residents spanning 3 to 36 months in length. Outcomes are specified to be a function of resident demographic and diagnostic attributes and facility-level operating and nurse staffing attributes. PRINCIPAL FINDINGS: The estimated parameters for resident demographic and diagnostic attributes showed a great deal of construct validity with respect to clinical expectations regarding risk factors for adverse outcomes. Few facility attributes were associated with outcomes generally, and none was significantly associated with all four outcomes. CONCLUSIONS: The absence of uniform associations between facility attributes and the various long-term care health outcomes studied suggests that strong facility performance on one health outcome may coexist with much weaker performance on other outcomes. This has implications for the aggregation of individual facility performance measures on multiple outcomes and the development of overall outcome performance measures. PMID:9776939

Porell, F; Caro, F G; Silva, A; Monane, M

1998-01-01

299

Longitudinal Variability in the Geomagnetically Quiescent Ionosphere  

NASA Astrophysics Data System (ADS)

We report on the effects of nonmigrating tides on the Earth's upper atmosphere based upon calculations made with the National Center for Atmospheric Research (NCAR) thermosphere-ionosphere- mesosphere-electrodynamics general circulation model (TIME-GCM) and global-scale wave model (GSWM). We extend the results reported by Hagan et al. (2007) who demonstrated that longitude variations in IMAGE satellite airglow brightness measurements associated with equatorial ionization anomaly peak densities can be attributed to longitudinally variable nonmigrating zonal wind tides which modulate the E-region dynamo and produce electric field effects that map into the F-region aloft. We explore the local time, altitude and seasonal variability of these nonmigrating tidal components in the TIME-GCM along with viable sources of excitation, including latent heat release associated with raindrop formation in deep convective towers in the tropical troposphere as parameterized in the GSWM. We also assess the reliability of our TIME-GCM predictions via comparison with accessible observations of the quiescent ionosphere. Hagan, M.E., A. Maute, R. G. Roble, A. D. Richmond, T. J. Immel, and S. L. England, (2007), Connections between deep tropical clouds and the Earths ionosphere, Geophys. Res. Lett., in press.

Hagan, M. E.; Maute, A.; Roble, R. G.; Richmond, A. D.

2007-12-01

300

NASA Planetary Science Summer School: Longitudinal Study  

NASA Astrophysics Data System (ADS)

NASA’s Planetary Science Summer School is a program designed to prepare the next generation of scientists and engineers to participate in future missions of solar system exploration. The opportunity is advertised to science and engineering post-doctoral and graduate students with a strong interest in careers in planetary exploration. Preference is given to U.S. citizens. The “school” consists of a one-week intensive team exercise learning the process of developing a robotic mission concept into reality through concurrent engineering, working with JPL’s Advanced Project Design Team (Team X). This program benefits the students by providing them with skills, knowledge and the experience of collaborating with a concept mission design. A longitudinal study was conducted to assess the impact of the program on the past participants of the program. Data collected included their current contact information, if they are currently part of the planetary exploration community, if participation in the program contributed to any career choices, if the program benefited their career paths, etc. Approximately 37% of 250 past participants responded to the online survey. Of these, 83% indicated that they are actively involved in planetary exploration or aerospace in general; 78% said they had been able to apply what they learned in the program to their current job or professional career; 100% said they would recommend this program to a colleague.

Giron, Jennie M.; Sohus, A.

2006-12-01

301

8. VIEW OF UNDERSIDE OF BRIDGE, SHOWING LONGITUDINAL SUPPORTING IBEAMS, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW OF UNDERSIDE OF BRIDGE, SHOWING LONGITUDINAL SUPPORTING I-BEAMS, CORRUGATED IRON ARCH REINFORCEMENTS, TIE RODS, AND EASTERN POURED CONCRETE ABUTMENT. FACING EAST. - Brevard Bridge, Spanning Westland Run at Ullom Road, Export, Washington County, PA

302

5. PHOTOCOPY, LONGITUDINAL SECTION, FIRST, SECOND, THIRD FLOOR PLANS, FROM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. PHOTOCOPY, LONGITUDINAL SECTION, FIRST, SECOND, THIRD FLOOR PLANS, FROM AMERICAN ARCHITECT AND BUILDING NEWS, VOL. 24, No. 657-JULY 28, 1888 - Cambridge City Hall, 795 Massachusetts Avenue, Cambridge, Middlesex County, MA

303

A NEW METHOD OF LONGITUDINAL DIARY ASSEMBLY FOR EXPOSURE MODELING  

EPA Science Inventory

Many stochastic human exposure models require the construction of longitudinal time-activity diaries to evaluate the time sequence of concentrations encountered, and hence, the pollutant exposure for the simulated individuals. However, most of the available data on human activiti...

304

A pattern-clustering method for longitudinal data -heroin users  

E-print Network

A pattern-clustering method for longitudinal data - heroin users receiving methadone CHIEN-JU LIN for supporting me spiritually throughout my life. iii #12;Abstract Methadone is used as a substitute of heroin

Jones, Peter JS

305

Agile Customer Engagement: a Longitudinal Qualitative Case Study  

E-print Network

Agile Customer Engagement: a Longitudinal Qualitative Case Study Geir Kjetil Hanssen SINTEF ICT S Customer Engagement, Agile Process, Stakeholder Management, Process Transition. 1. INTRODUCTION Software characteristics of traditional approaches, agile methodologies suggest a different approach, emphasizing close

306

LONGITUDINAL VIEW OF THE SOAKING PIT BUILDING INTERIOR WITH OPEN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LONGITUDINAL VIEW OF THE SOAKING PIT BUILDING INTERIOR WITH OPEN HEARTH IN BACKGROUND AND FURNACE PIT/ STACK AREA TO THE LEFT. - Pittsburgh Steel Company, Monessen Works, Open Hearth Plant, Donner Avenue, Monessen, Westmoreland County, PA

307

Determining longitudinal dispersion coefficients for submerged vegetated flow  

NASA Astrophysics Data System (ADS)

Prediction of the physical transport and mixing of pollutants or other soluble material is crucial for effective river management. Although well established methods exist which describe mixing processes in open channel flow, the presence of vegetation has a significant impact on mixing and few existing techniques account for this. To date, existing models which predict longitudinal dispersion coefficients in vegetated open channel flow have been derived and verified based on experiments conducted in simulated vegetation. This paper presents observations of longitudinal dispersion coefficients in a channel featuring living vegetation and tests against both an existing and a newly proposed model for longitudinal dispersion coefficient in submerged vegetated open channel flow. A model based on a mathematical technique of predicting dispersion in plain shear flow is shown to be capable of predicting longitudinal dispersion coefficients to within 20%.

Shucksmith, J. D.; Boxall, J. B.; Guymer, I.

2011-10-01

308

Longitudinal structure of ballooning MHD disturbances in a model magnetosphere  

NASA Astrophysics Data System (ADS)

Large-scale toroidal Pc5 pulsations are commonly treated as Alfven oscillations of a magnetic field line. According to observations, their longitudinal structure is described well by theory. At the same time, the longitudinal structure of azimuthal small-scale poloidal Pc5 pulsations is virtually unknown. These pulsations are associated with ballooning disturbances described by a system of coupled equations for Alfvenic and slow magnetosonic (SMS) modes. In this work, the Voigt model is used to describe the equilibrium finite-pressure plasma configuration in an inhomogeneous magnetosphere plasma in a curved magnetic field. Spectral characteristics and the spatial structure of natural ballooning modes are calculated for this model. The model calculations demonstrate the possibility of different longitudinal scales for transverse and longitudinal magnetic components of oscillations near the top of the field line.

Mazur, N. G.; Fedorov, E. N.; Pilipenko, V. A.

2014-05-01

309

Expanding the longitudinal magnetoimpedance sensor range by direct bias current  

NASA Astrophysics Data System (ADS)

We investigated the effects of induced helical anisotropy and application of dc bias current IB on longitudinal magnetoimpedance (MI) in amorphous microwires both separately and together. We demonstrated that when both parameters are present, i.e., a dc bias current IB is applied to the microwire with induced helical anisotropy, the longitudinal MI sensor range can be considerably extended up to the fields considerably higher than its anisotropy field as the slope of MI curve dZ /dHE remains rather high. A highly asymmetric longitudinal MI dependence with a rather high slope at the zero-field point was obtained. Reversing the bias current IB causes reversal of the bias field direction and results in a mirroring of the MI dependence. This gives a possibility to determine both the sign and the magnitude of the external magnetic field. The obtained results can be used in development of the longitudinal MI sensors with increased sensitivity and/or range.

Ipatov, M.; Zhukova, V.; Zhukov, A.; Gonzalez, J.

2013-05-01

310

Further development of a pore site in longitudinal view.  

NSDL National Science Digital Library

Further development of a pore site in longitudinal view. Callose nearly fused at middle lamella, plasmalemma and ER cisternae cover the callose, plasmodesma extends from ER to ER through future pore. (Echium angustifolium petiole)

Esau, Katherine

2004-03-09

311

Longitudinal dispersion modeling in small streams  

NASA Astrophysics Data System (ADS)

The environmental problems caused by the increasing of pollutant loads discharged into natural water bodies are very complex. For that reason the cognition of transport mechanism and mixing characteristics in natural streams is very important. The mathematical and numerical models have become very useful tools for solving the water management problems. The mathematical simulations based on numerical models of pollution mixing in streams can be used (for example) for prediction of spreading of accidental contaminant waves in rivers. The paper deals with the estimation of the longitudinal dispersion coefficients and with the numerical simulation of transport and transformation of accidental pollution in the small natural streams. There are different ways of solving problems of pollution spreading in open channels, in natural rivers. One of them is the hydrodynamic approach, which endeavours to understand and quantify the spreading phenomenon in a stream. The hydrodynamic models are based on advection-diffusion equation and the majority of them are one-dimensional models. Their disadvantage is inability to simulate the spread of pollution until complete dispersion of pollutant across the stream section is finished. Two-dimensional mixing models do not suffer from these limitations. On the other hand, the one-dimensional models are simpler than two-dimensional ones, they need not so much input data and they are often swifter. Three-dimensional models under conditions of natural streams are applicable with difficulties (or inapplicable) for their complexity and demands on accuracy and amount of input data. As there was mentioned above the two-dimensional models can be used also until complete dispersion of pollutant across the stream section is not finished, so we decided to apply the two-dimensional model SIRENIE. Experimental microbasin Rybarik is the part of the experimental Mostenik brook basin of IH SAS Bratislava. It was established as a Field Hydrological Laboratory in 1958. Since 1986 started a chemical program in the basin. The total area of the Rybarik basin is 0.119 km2. The length of the stream from spring to closing profile is 256 m, the mean slope of the stream is 9.1%, and the mean slope of the basin is 14.9%. The elevation is from 369 to 434 m above the sea level. The geological conditions in the Rybarik basin are characterized by flysh substrates (altering layers of clay and sandstones). The basin is from 2/3 cultivated by the state farm, private farmer covers the rest of the area. The forest coverage during the period 1986-2004 was approximately 10%, rest of the land is arable. NaCl (10-30 g) was injected to the Rybárik brook at different water levels and in different seasons. The electric conductivity was measured 100 and 250 m downstream the injection point. The samples were taken for Cl- concentration analyses during the first cases. The Cl and EC waves were identical. Coefficients of the longitudinal dispersion were estimated by trial-error method in the Rybárik brook using model SIRENIE. Coefficients were in range of 0.2 - 0.7 m2.s-1. Acknowledgement: This work was supported by project VEGA 0010/11.

Pekarova, Pavla; Pekar, Jan; Miklanek, Pavol

2014-05-01

312

Longitudinal Diffusion Tensor Imaging in Frontotemporal Dementia  

PubMed Central

Objective Novel biomarkers for monitoring progression in neurodegenerative conditions are needed. Measurement of microstructural changes in white matter (WM) using diffusion tensor imaging (DTI) may be a useful outcome measure. Here we report trajectories of WM change using serial DTI in a cohort with behavioral variant frontotemporal dementia (bvFTD). Methods Twenty-three patients with bvFTD (12 having genetic mutations), and 18 age-matched control participants were assessed using DTI and neuropsychological batteries at baseline and ?1.3 years later. Baseline and follow-up DTI scans were registered using a groupwise approach. Annualized rates of change for DTI metrics, neuropsychological measures, and whole brain volume were calculated. DTI metric performances were compared, and sample sizes for potential clinical trials were calculated. Results In the bvFTD group as a whole, rates of change in fractional anisotropy (FA) and mean diffusivity (MD) within the right paracallosal cingulum were greatest (FA: ?6.8%/yr, p?longitudinal DTI may be a useful biomarker in future clinical trials. PMID:25363208

Mahoney, Colin J; Simpson, Ivor J A; Nicholas, Jennifer M; Fletcher, Phillip D; Downey, Laura E; Golden, Hannah L; Clark, Camilla N; Schmitz, Nicole; Rohrer, Jonathan D; Schott, Jonathan M; Zhang, Hui; Ourselin, Sebastian; Warren, Jason D; Fox, Nick C

2015-01-01

313

Future Orientation, Impulsivity, and Problem Behaviors: A Longitudinal Moderation Model  

Microsoft Academic Search

In the current study, based on a sample of 1,873 adolescents between 11.4 and 20.9 years of age from the first 3 waves of the National Longitudinal Study of Adolescent Health, we investigated the longitudinal effects of future orientation on levels of and developmental changes in problem behaviors, while controlling for the effects by impulsivity; we also tested the moderating

Pan Chen; Alexander T. Vazsonyi

2011-01-01

314

Cocaine, Anemia, and Neurodevelopmental Outcomes in Children: A Longitudinal Study  

Microsoft Academic Search

This longitudinal study investigated the rates of iron-deficiency (ID) and iron-deficiency anemia (IDA) among prenatally cocaine-exposed and nonexposed two- and four-year-old children and assessed their relationships to neurodevelopmental outcomes. The sample consisted of 143 two-year-old (70 exposed and 73 nonexposed) and 274 four-year-old (139 exposed and 135 nonexposed) low socioeconomic status children recruited from an ongoing longitudinal study. Hematological assessments

SUCHITRA NELSON; EDITH LERNER; ROBERT NEEDLMAN; ANN SALVATOR; LYNN T. SINGER

2004-01-01

315

First Observation of the Exchange of Transverse and Longitudinal Emittances  

SciTech Connect

An experimental program to demonstrate a novel phase-space manipulation in which the horizontal and longitudinal emittances of a particle beam are exchanged has been completed at the Fermilab A0 Photoinjector. A new beam line, consisting of a TM{sub 110} deflecting mode cavity flanked by two horizontally dispersive doglegs has been installed. We report on the first direct observation of transverse and longitudinal emittance exchange.

J Ruan; A Johnson; A Lumpkin; R Thurman-Keup; H Edwards; R Fliller; T Koeth; Y Sun

2011-12-31

316

Factors affecting longitudinal trajectories of plasma sphingomyelins: the Baltimore Longitudinal Study of Aging.  

PubMed

Sphingomyelin metabolism has been linked to several diseases and to longevity. However, few epidemiological studies have quantified individual plasma sphingomyelin species (identified by acyl-chain length and saturation) or their relationship between demographic factors and disease processes. In this study, we determined plasma concentrations of distinct sphingomyelin species in 992 individuals, aged 55 and older, enrolled in the Baltimore Longitudinal Study of Aging. Participants were followed, with serial measures, up to 6 visits and 38 years (3972 total samples). Quantitative analyses were performed on a high-performance liquid chromatography-coupled electrospray ionization tandem mass spectrometer. Linear mixed models were used to assess variation in specific sphingomyelin species and associations with demographics, diseases, medications or lifestyle factors, and plasma cholesterol and triglyceride levels. We found that most sphingomyelin species increased with age. Women had higher plasma levels of all sphingomyelin species and showed steeper trajectories of age-related increases compared to men. African Americans also showed higher circulating sphingomyelin concentrations compared to Caucasians. Diabetes, smoking, and plasma triglycerides were associated with lower levels of many sphingomyelins and dihydrosphingomyelins. Notably, these associations showed specificity to sphingomyelin acyl-chain length and saturation. These results demonstrate that longitudinal changes in circulating sphingomyelin levels are influenced by age, sex, race, lifestyle factors, and diseases. It will be important to further establish the intra-individual age- and sex-specific changes in each sphingomyelin species in relation to disease onset and progression. PMID:25345489

Mielke, Michelle M; Bandaru, Veera Venkata Ratnam; Han, Dingfen; An, Yang; Resnick, Susan M; Ferrucci, Luigi; Haughey, Norman J

2015-02-01

317

Modeling Longitudinal Data Containing Non-Normal Within Subject Errors  

NASA Technical Reports Server (NTRS)

The mission of the National Aeronautics and Space Administration’s (NASA) human research program is to advance safe human spaceflight. This involves conducting experiments, collecting data, and analyzing data. The data are longitudinal and result from a relatively few number of subjects; typically 10 – 20. A longitudinal study refers to an investigation where participant outcomes and possibly treatments are collected at multiple follow-up times. Standard statistical designs such as mean regression with random effects and mixed–effects regression are inadequate for such data because the population is typically not approximately normally distributed. Hence, more advanced data analysis methods are necessary. This research focuses on four such methods for longitudinal data analysis: the recently proposed linear quantile mixed models (lqmm) by Geraci and Bottai (2013), quantile regression, multilevel mixed–effects linear regression, and robust regression. This research also provides computational algorithms for longitudinal data that scientists can directly use for human spaceflight and other longitudinal data applications, then presents statistical evidence that verifies which method is best for specific situations. This advances the study of longitudinal data in a broad range of applications including applications in the sciences, technology, engineering and mathematics fields.

Feiveson, Alan; Glenn, Nancy L.

2013-01-01

318

Specific features of formation and evolution of a longitudinal autosoliton in p-InSb in a longitudinal magnetic field  

SciTech Connect

The effect of a longitudinal magnetic field on the formation and behavior of a longitudinal autosoliton in the excited nonequilibrium electron-hole plasma in p-InSb is studied experimentally. It is shown that, in a longitudinal magnetic field, the threshold characteristics of the formation of an autosoliton are reduced and the autosoliton takes on the diamagnetic properties that persist after removal of the magnetic field. In magnetic fields of 9.6 x 10{sup 3}-4.6 x 10{sup 4} A m{sup -1}, instabilities of the autosoliton current are excited, with a frequency in the range 2-20 kHz. In this case, the amplitude and frequency of these instabilities depend on the magnetic field. At elevated levels of excitation of the autosoliton and in increased magnetic fields, the instability of the longitudinal-autosoliton current exhibits synergetic properties.

Kamilov, I. K.; Stepurenko, A. A., E-mail: stepurenko-a@yandex.ru; Gummetov, A. E. [Russian Academy of Sciences, Institute of Physics, Dagestan Research Center (Russian Federation)

2010-06-15

319

Theoretical study of transverse-longitudinal emittance coupling  

SciTech Connect

The effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions is investigated using the generalized Courant-Snyder theory for coupled lattices. Recently, the concept and technique of transverse-longitudinal emittance coupling have been proposed for applications in the Linac Coherent Light Source and other free-electron lasers to reduce the transverse emittance of the electron beam. Such techniques can also be applied to the driver beams for the heavy ion fusion and beam-driven high energy density physics, where the transverse emittance budget is typically tighter than the longitudinal emittance. The proposed methods consist of one or several coupling components which completely swap the emittances of one of the transverse directions and the longitudinal direction at the exit of the coupling components. The complete emittance exchange is realized in one pass through the coupling components. In the present study, we investigate the effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions. A weak coupling component is introduced at every focusing lattice, and we would like to determine if such a lattice can realize the function of emittance exchange.

Qin, H; Davidson, R C; Chung, M; Barnard, J J; Wang, T F

2011-04-14

320

Flexible marginalized models for bivariate longitudinal ordinal data  

PubMed Central

Random effects models are commonly used to analyze longitudinal categorical data. Marginalized random effects models are a class of models that permit direct estimation of marginal mean parameters and characterize serial correlation for longitudinal categorical data via random effects (Heagerty, 1999). Marginally specified logistic-normal models for longitudinal binary data. Biometrics 55, 688–698; Lee and Daniels, 2008. Marginalized models for longitudinal ordinal data with application to quality of life studies. Statistics in Medicine 27, 4359–4380). In this paper, we propose a Kronecker product (KP) covariance structure to capture the correlation between processes at a given time and the correlation within a process over time (serial correlation) for bivariate longitudinal ordinal data. For the latter, we consider a more general class of models than standard (first-order) autoregressive correlation models, by re-parameterizing the correlation matrix using partial autocorrelations (Daniels and Pourahmadi, 2009). Modeling covariance matrices via partial autocorrelations. Journal of Multivariate Analysis 100, 2352–2363). We assess the reasonableness of the KP structure with a score test. A maximum marginal likelihood estimation method is proposed utilizing a quasi-Newton algorithm with quasi-Monte Carlo integration of the random effects. We examine the effects of demographic factors on metabolic syndrome and C-reactive protein using the proposed models. PMID:23365416

Lee, Keunbaik; Daniels, Michael J.; Joo, Yongsung

2013-01-01

321

Nonlinear Cascade Strategy for Longitudinal Control of Electric Vehicle.  

PubMed

The problem of controlling the longitudinal motion of front-wheels electric vehicle (EV) is considered making the focus on the case where a single dc motor is used for both front wheels. Chassis dynamics are modelled applying relevant fundamental laws taking into account the aerodynamic effects and the road slope variation. The longitudinal slip, resulting from tire deformation, is captured through Kiencke's model. Despite its highly nonlinear nature the complete model proves to be utilizable in longitudinal control design. The control objective is to achieve a satisfactory vehicle speed regulation in acceleration/deceleration stages, despite wind speed and other parameters uncertainty. An adaptive controller is developed using the backstepping design technique. The obtained adaptive controller is shown to meet its objectives in presence of the changing aerodynamics efforts and road slope. PMID:24895464

El Majdoub, K; Giri, F; Ouadi, H; Chaoui, F Z

2014-01-01

322

Simulation of the ALS longitudinal multibunch feedback system  

SciTech Connect

Longitudinal coupled bunch growth rates in the Advanced Light Source (ALS), a 1.5 GeV electron storage ring for producing synchrotron radiation, indicate the need for damping via a feedback (FB) system. The design of the system is based on the proposed PEP-II longitudinal FB system which uses a digital filter to provide the required phase and amplitude response. We report the results of a detailed computer simulation of the FB system including single particle longitudinal beam dynamics, measured RF cavity fundamental and higher order modes, and response of major FB components such as the power amplifier and kicker. The simulation addresses issues such as required FB power and gain, noise, digital filter effects, and varying initial bunch conditions.

Byrd, J.

1993-05-01

323

Longitudinal research with sexual assault survivors: a methodological review.  

PubMed

Longitudinal research designs are relatively rare in the academic literature on rape and sexual assault despite their tremendous methodological rigor and scientific utility. In the interest of promoting wider use of such methods, we conducted a methodological review of projects that have used prospective longitudinal designs to study the occurrence of sexual victimization throughout the lifespan and/or the process of change during rape recovery (N = 32 projects). Five questions were examined: (a) What were the substantive foci of these longitudinal studies? (b) How were survivors recruited? (c) What participation rates were typical? (d) How long were participants followed over time and with what success rates? and (e) What incentives were used to increase participation? Most studies focused on postassault sequelae and recruited survivors from hospital emergency departments and other first-response help-seeking sites with highly variable participation rates. Retention rates were comparable across studies (approximately 70%). PMID:20724293

Campbell, Rebecca; Sprague, Heather Brown; Cottrill, Sara; Sullivan, Cris M

2011-02-01

324

Regulatory Issues Encountered when Conducting Longitudinal Substance Abuse Research  

PubMed Central

Objective To summarize challenges unique to obtaining Institutional Review Board (IRB) approval for longitudinal substance abuse research, focusing on solutions and lessons learned. Methods Thirteen senior Principal Investigators with experience conducting research on substance abuse treatment and health services outcomes recalled instances from the prior 5 years when obtaining UCLA and non-UCLA IRB approval was hampered by differences in the interpretation of regulatory guidelines and how those differences were resolved. Principal Findings Comprehensive yet flexible research protocols regarding (1) informed and voluntary consent, (2) participant payment, and (3) re-contact efforts are essential for securing IRB approval of longitudinal substance abuse studies. Specific examples of lessons learned are provided. Conclusions Experiences can help researchers to provide appropriate and explicit justification for longitudinal substance abuse research protocols, thereby minimizing the burden and cost associated with meeting regulatory requirements as well as enhancing the efficiency, quantity, and quality of data collected. PMID:20379383

Evans, Elizabeth; Murphy, Debra A.; Grella, Christine E.; Mouttapa, Michele; Hser, Yih-Ing

2008-01-01

325

Calibration of the initial longitudinal momentum spread of tunneling ionization  

NASA Astrophysics Data System (ADS)

Recently, the initial longitudinal momentum at the tunnel exit has attracted considerable interest in the strong-field community. We have measured the photoelectron momentum distribution of Kr atoms at an intensity of 1.2×1014W/cm2 and the ellipticity-resolved angular distribution of Ne atoms at an intensity of 3.6×1014W/cm2 (790-nm, 25-fs laser pulses). To shed more light on the debated issue, we have introduced an initial longitudinal momentum spread at the tunnel exit to compare with the measured photoelectron angular distributions using a dedicated semiclassical model. The simulation indicates that the value of this longitudinal momentum spread is in the range 0.0-0.1 a.u., which is less than the initial transverse momentum spread predicted by the tunneling theory.

Sun, Xufei; Li, Min; Yu, Jizhou; Deng, Yongkai; Gong, Qihuang; Liu, Yunquan

2014-04-01

326

Young's modulus of BF wood material by longitudinal vibration  

NASA Astrophysics Data System (ADS)

All engineered structures are designed and built with consideration of resisting the same fundamental forces of tension, compression, shear, bending and torsion. Structural design is a balance of these internal and external forces. So, it is interesting to calculate the Young's moduli of Borassus Flabellifier BF wood are quite important from the application point of view. The ultrasonic waves are closely related with the elastic and inelastic properties of the materials. In the present study, we measured longitudinal wave ultrasonic velocities in BF wood material by longitudinal vibration method. After measuring ultrasonic velocity in BF wood material, we calculated Young's modulus of Borassus Flabellifier BF wood material. We used ultrasonic interferometer for measuring longitudinal wave ultrasonic velocity in BF wood material made by Mittal Enterprises, New Delhi, India in our laboratory. Borassus Flabellifier BF wood material was collected from Dhar district of Madhya Pradesh, India.

Phadke, Sushil; Darshan Shrivastava, Bhakt; Mishra, Ashutosh; Dagaonkar, N.

2014-09-01

327

A radio-frequency quadrupole accelerator longitudinal field stabilizer  

SciTech Connect

The fields in a 600-MHz model of a radio-frequency quadrupole (RFQ) accelerator have been longitudinally stabilized over 86% of its length. The stabilizing elements consist of four external transverse electromagnetic (TEM) lines. Each line is coupled to the RFQ by two magnetic loops attached to voltage maxima of the TEM line. These resonant lines stabilize the RFQ fields by providing an alternate longitudinal power flow path in the RFQ. Stabilization depends on the TEM line Q and the TEM line RFQ coupling. Each stabilizer coupling-loop location in the RFQ needs to be fully azimuthally stabilized. Substantial coupling between stabilizer elements destroys stabilization. 3 refs., 13 figs., 2 tabs.

Gray, E.R.; Spalek, G.; Shapiro, A.

1988-01-01

328

Longitudinal fMRI analysis: A review of methods  

PubMed Central

Functional magnetic resonance imaging (fMRI) investigations of a longitudinal nature, where participants are scanned repeatedly over time and imaging data are obtained at more than one time-point, are essential to understanding functional changes and development in healthy and pathological brains. The main objective of this paper is to provide a brief summary of common longitudinal analysis approaches, develop an overview of fMRI by introducing how such data manifest, and explore the statistical challenges that arise at the intersection of these two techniques. PMID:21691445

Skup, Martha

2010-01-01

329

Longitudinal fMRI analysis: A review of methods  

PubMed Central

Functional magnetic resonance imaging (fMRI) investigations of a longitudinal nature, where participants are scanned repeatedly over time and imaging data are obtained at more than one time-point, are essential to understanding functional changes and development in healthy and pathological brains. The main objective of this paper is to provide a brief summary of common longitudinal analysis approaches, develop an overview of fMRI by introducing how such data manifest, and explore the statistical challenges that arise at the intersection of these two techniques. PMID:22655113

Skup, Martha

2011-01-01

330

Pre-, Post-, and Longitudinal Evaluation of Juvenile Justice Education.  

ERIC Educational Resources Information Center

Describes two stages of the Juvenile Justice Educational Enhancement Program's pre-, post-, and longitudinal evaluation research and reports on the pilot studies used to explore how to design statewide research on pre- and post-assessment scores and community reintegration outcomes. Findings suggest that higher performing programs produce greater…

Major, Aline K.; Chester, Deborah R.; McEntire, Ranee; Waldo, Gordon P.; Blomberg, Thomas G.

2002-01-01

331

Longitudinal Effects of Domestic Violence on Employment and Welfare Outcomes  

ERIC Educational Resources Information Center

This study uses longitudinal data spanning 13 years from a study of 234 adolescent mothers to evaluate the effects of cumulative domestic violence on employment and welfare use before and after welfare reform. Domestic violence increased the odds of unemployment after welfare reform, but not before; domestic violence had no effect on welfare use…

Lindhorst, Taryn; Oxford, Monica; Gillmore, Mary Rogers

2007-01-01

332

Anxiety Sensitivity and Panic Attacks: A 1-Year Longitudinal Study  

ERIC Educational Resources Information Center

The hypothesis that anxiety sensitivity (AS) is a risk factor for panic genesis has obtained compelling support, but the clinical/practical importance of AS in panic genesis has been questioned. In addition, the association between panic experience and AS increase has not been clearly demonstrated. Through this 1-year longitudinal study among…

Li, Wen; Zinbarg, Richard E.

2007-01-01

333

Joint modeling of longitudinal categorical data and survival Jianwen Cai  

E-print Network

Joint modeling of longitudinal categorical data and survival data by Jianwen Cai University time. In this talk, we will discuss such joint models. Random effects are introduced to illustrate our approaches. This is joint work with Jaeun Choi and Donglin Zeng. #12;

Jin, Jiashun

334

Longitudinal Relationships Between Childhood, Adolescent, and Adult Eating Disorders  

Microsoft Academic Search

ObjectiveThis study investigates the longitudinal course of eating problems from childhood though adulthood. The following questions are answered: (1) How stable are eating disorder symptoms and diagnoses over a 17-year interval from childhood to adulthood? (2) Do early childhood eating problems predict the occurrence of eating disorders in adulthood?

LISA A. KOTLER; PATRICIA COHEN; MARK DAVIES; DANIEL S. PINE; B. TIMOTHY WALSH

2001-01-01

335

Patterns of Doctoral Student Degree Completion: A Longitudinal Analysis  

ERIC Educational Resources Information Center

Despite decades of interest in Ph.D. student outcomes, there have been few comprehensive studies of doctoral student completion. Compared to research on undergraduate students, longitudinal studies of doctoral student completion in multiple disciplines at multiple institutions are exceptionally rare. As a consequence, there is relatively scant…

Most, David E.

2008-01-01

336

Longitudinal evaluation of growth changesin class II division 1 subjects  

Microsoft Academic Search

Longitudinal records from the Ohio State University Growth Study were used to compare the skeletal growth changes between Class II division 1 and Class I female subjects between ages 7 and 14. Tensor analysis was used to determine the yearly growth rate and direction. No significant difference was found in cranial base dimension between the Class I and Class II

Peter W. Ngan; Ewa Byczek; John Scheick

1997-01-01

337

Prompting in CALL: A Longitudinal Study of Learner Uptake  

ERIC Educational Resources Information Center

This research presents a longitudinal study of learner uptake in a computer-assisted language learning (CALL) environment. Over the course of 3 semesters, 10 second language learners of German at a Canadian university used an online, parser-based CALL program that, for the purpose of this research, provided 2 different types of feedback of varying…

Heift, Trude

2010-01-01

338

Revisiting the Dedifferentiation Hypothesis with Longitudinal Multi-Cohort Data  

ERIC Educational Resources Information Center

The present longitudinal multi-cohort study examines whether interindividual variability in cognitive performance and change increases in old age, and whether associations among developments of different cognitive functions increase with adult age. Multivariate multiple-group latent growth modeling was applied to data from narrow cohorts separated…

de Frias, Cindy M.; Lovden, Martin; Lindenberger, Ulman; Nilsson, Lars-Goran

2007-01-01

339

IVUS-based Histology of Atherosclerotic plaques: Improving Longitudinal Resolution  

E-print Network

IVUS-based Histology of Atherosclerotic plaques: Improving Longitudinal Resolution Arash Takia ABSTRACT Although Virtual Histology (VH) is the in-vivo gold standard for atherosclerosis plaque is the Virtual Histology (VH).3 VH provides a colored coded plaque characterization image by analyzing

Yanikoglu, Berrin

340

A Longitudinal Study of Judge Leniency and Consistency.  

ERIC Educational Resources Information Center

This retrospective longitudinal study was designed to show grading leniency patterns of judges within and across clinical examination administrations. Data from 17 different administrations of the histology examination of the American Society of Clinical Pathologists over 10 years were studied. Over the 10 years there were 4,683 candidates and 57…

Lunz, Mary E.; O'Neill, Thomas R.

341

Acquisition patterns of financial products: A longitudinal investigation  

Microsoft Academic Search

Acquisition pattern analysis investigates orders in which households acquire products. Extant empirical studies employ cross-sectional data, providing limited insight into acquisition orders and no insight into timing of product acquisitions. We use an extensive longitudinal database for studying acquisition patterns in the financial product market, in particular financial assets. We find support for a common order of acquisition, reflecting risk

Leonard J. Paas; Tammo H. A. Bijmolt; Jeroen K. Vermunt

2007-01-01

342

Sasaki Metrics for Analysis of Longitudinal Data on Manifolds  

PubMed Central

Longitudinal data arises in many applications in which the goal is to understand changes in individual entities over time. In this paper, we present a method for analyzing longitudinal data that take values in a Riemannian manifold. A driving application is to characterize anatomical shape changes and to distinguish between trends in anatomy that are healthy versus those that are due to disease. We present a generative hierarchical model in which each individual is modeled by a geodesic trend, which in turn is considered as a perturbation of the mean geodesic trend for the population. Each geodesic in the model can be uniquely parameterized by a starting point and velocity, i.e., a point in the tangent bundle. Comparison between these parameters is achieved through the Sasaki metric, which provides a natural distance metric on the tangent bundle. We develop a statistical hypothesis test for differences between two groups of longitudinal data by generalizing the Hotelling T2 statistic to manifolds. We demonstrate the ability of these methods to distinguish differences in shape changes in a comparison of longitudinal corpus callosum data in subjects with dementia versus healthily aging controls.

Muralidharan, Prasanna; Fletcher, P. Thomas

2014-01-01

343

Suprasegmental Phonology Development and Reading Acquisition: A Longitudinal Study  

ERIC Educational Resources Information Center

Previous studies implicate suprasegmental phonology in reading acquisition. However, little is known about how suprasegmental sensitivity develops or how it contributes to reading. Here, 130 Spanish primary-school children participated in this 2-year longitudinal study. Nonlinguistic rhythm, lexical-stress sensitivity and metrical-stress…

Calet, Nuria; Gutiérrez-Palma, Nicolás; Simpson, Ian C.; González-Trujillo, M. Carmen; Defior, Sylvia

2015-01-01

344

Alternative Structural Models for Multivariate Longitudinal Data Analysis  

ERIC Educational Resources Information Center

Structural equation models are presented as alternative models for examining longitudinal data. The models include (a) a cross-lagged regression model, (b) a factor model based on latent growth curves, and (c) a dynamic model based on latent difference scores. The illustrative data are on motivation and perceived competence of students during…

Ferrer, Emilio; McArdle, John

2003-01-01

345

The Third Wave of Longitudinal Data Systems: Data Partnerships  

ERIC Educational Resources Information Center

States have made dramatic progress in the past few years in implementing longitudinal data systems (LDS) to improve student achievement. These systems collect and house student educational data that make it easy for policymakers and practitioners to access and use it for reporting, policymaking and decision making. So much has happened in states…

Armstrong, Jane; Bergner, Terry; Smith, Nancy

2008-01-01

346

Effects of First Occasion Test Experience on Longitudinal Cognitive Change  

ERIC Educational Resources Information Center

Effects of additional test experience on longitudinal change in 5 cognitive abilities was examined in a sample of healthy adults ranging from 18 to 80 years of age. Participants receiving experience with parallel versions of the cognitive tests on the first occasion had more positive cognitive change an average of 2.5 years later than participants…

Salthouse, Timothy A.

2013-01-01

347

A Longitudinal Investigation of Peer Sexual Harassment Victimization in Adolescence  

ERIC Educational Resources Information Center

The current study describes longitudinal trends in sexual harassment by adolescent peers and highlights gender, pubertal status, attractiveness, and power as predictors of harassment victimization. At the end of 5th, 7th, and 9th grades, 242 adolescents completed questionnaires about sexual harassment victimization, pubertal status, and perceived…

Petersen, Jennifer L.; Hyde, Janet Shibley

2009-01-01

348

A Longitudinal Study of Psychological Burnout in Teachers  

Microsoft Academic Search

This longitudinal study examined antecedents and consequences of psychological burnout among human service professionals. Antecedents of psychological burnout included individual and situational characteristics, work stressors, and measures of social support. Consequences of psychological burnout emphasized satisfaction and emotional and physical well-being variables. Participants in the study were 362 school-based educators (teachers and administrators) employed by the same school board. Respondents

Ronald J. Burke; Esther Greenglass

1995-01-01

349

Reciprocal Longitudinal Relations Between Nonresident Father Involvement and Adolescent Delinquency  

Microsoft Academic Search

Using a representative sample of low-income, primarily minority adolescents (N 5647, aged 10-14 years at Wave 1), this study examined bidirectional longitudinal relations between nonresident father involvement, defined as contact and responsibility for children's care and behavior, and adolescent engagement in delinquent activities. Autoregressive and fixed effects models found that higher nonresident father involvement predicted subsequent decreases in adolescent delinquency,

Rebekah Levine Coley; Bethany L. Medeiros

2007-01-01

350

Longitudinal control of the lead car of a platoon  

Microsoft Academic Search

The work presented here belongs to the area of Intelligent Highway Vehicle Systems (IHVS). In particular it deals with the scenario where cars move along the highway in tightly spaced platoons. We present the control schemes that perform the major longitudinal tasks that will be required from the lead vehicle of a platoon moving on an automated highway. In particular

Datta N. Godbole; John Lygeros

1994-01-01

351

Physical Simulation of Longitudinal Welding in Porthole-Die Extrusion  

Microsoft Academic Search

In porthole-die extrusion, the metal flowing through the die has to split up around the webs and then rejoin creating longitudinal welds that extend along the whole profile. The formation and quality of these welds depend on the metal flow around the webs and a number of process parameters such as the thermal and mechanical history stored in the material

P. F. Bariani; S. Bruschi; A. Ghiotti

2006-01-01

352

THE NATURE AND DEVELOPMENT OF GIFTEDNESS: A LONGITUDINAL STUDY  

Microsoft Academic Search

Following a short discussion of conceptual and theoretical problems of giftedness, the methodological foundations and selected results of a (presently) four year longitudinal study are presented. This study is based on a multidimensional concept of giftedness: intelligence, creativity, social competence, musical ability, psychomotor ability (or practical intelligence). Both academic achievements and leisure activities, as well as cognitive and motivational personality

Kurt A. Heller

1991-01-01

353

Traumatic longitudinal splitting of the inferior rectus muscle  

PubMed Central

Orbital floor fractures and associated injuries can cause strabismus. We present the case of a 34-year-old man with incomitant strabismus following orbital reconstruction after a high-impact baseball injury. Multipositional, high-resolution magnetic resonance imaging (MRI) revealed extensive longitudinal splitting of the inferior rectus muscle by an orbital floor implant that separated its orbital and global layers. PMID:21463958

Laursen, Jessica; Demer, Joseph L.

2011-01-01

354

A Longitudinal Study of Principals' Activities and Student Performance  

ERIC Educational Resources Information Center

Although a substantial amount of research on school leadership has focused on what principals may do to improve teaching and learning, little of this research has explored how principals' time spent on leadership activities may relate to and possibly affect student performance. This article presents results from a 3-year longitudinal study of…

May, Henry; Huff, Jason; Goldring, Ellen

2012-01-01

355

Longitudinal variability of methane and ammonia bands on Jupiter  

NASA Technical Reports Server (NTRS)

Results of a quantitative study of the longitudinal variations of methane and ammonia absorption on Jupiter are presented. A total of 78 high signal-to-noise ratio photoelectric spectra in the range 6000 to 6600 A were obtained on two consecutive nights, with complete longitudinal equatorial coverage each night through 9-min exposures covering a total of over 9 h. Analysis of the equivalent widths of the CH4 6190 A and NH3 6450 A absorption bands by means of a blind, automated, self-consistent method of continuum determination reveals large equivalent widths in both bands near longitudes of 35 and 340 deg and small equivalent widths near 150 deg, with a high degree of correlation between the equivalent widths of the bands. Continuum molecular absorption is found to be slightly negatively correlated with band equivalent widths. Radiative transfer calculations based on the model of Sato and Hansen (1979) using a doubling and adding technique indicate that the observed longitudinal variables of equivalent widths and continuum reflectivity are the results of longitudinal variations in ammonia cloud altitude.

Cochran, W. D.; Cochran, A. L.

1980-01-01

356

Using National Education Longitudinal Data Sets in School Counseling Research  

ERIC Educational Resources Information Center

National longitudinal databases hold much promise for school counseling researchers. Several of the more frequently used data sets, possible professional implications, and strategies for acquiring training in the use of large-scale national data sets are described. A 6-step process for conducting research with the data sets is explicated:…

Bryan, Julia A.; Day-Vines, Norma L.; Holcomb-McCoy, Cheryl; Moore-Thomas, Cheryl

2010-01-01

357

A Longitudinal Study: Phonological Changes Associated with Pharyngeal Flap Surgery.  

ERIC Educational Resources Information Center

The longitudinal study compared the speech of two children (beginning at age 3) with cleft palate and inadequate velopharyngeal closure in an attempt to identify the patterns of production observed prior to surgery and the course and rate of change in production following surgery. Subjects' speech samples were evaluated prior to pharyngeal flap…

Letcher, Lisa M.; And Others

358

Longitudinal Changes in Disabled Husbands' and Wives' Receipt of Care  

ERIC Educational Resources Information Center

Purpose of the Study: This study contrasts 2-year adjustments in disabled husbands' and wives' amount of received care following both worsening and recovery in personal (activities of daily living [ADLs]) and routine care (instrumental activities of daily living [IADLs]) disability. Design and Methods: Using longitudinal data on 789 husbands and…

Noel-Miller, Claire

2010-01-01

359

A Longitudinal Study of Welfare Exit among American Indian Families  

ERIC Educational Resources Information Center

Data from a longitudinal survey of families from three reservations (Navajo Nation, San Carlos, and Salt River) in Arizona were used to examine their probability of welfare use. Logistic regression models were used to estimate the effects of individual, family, and structural factors on welfare exit. Results indicate that their probability of…

Pandey, Shanta; Guo, Baorong

2007-01-01

360

Longitudinal Effects of Parental Bereavement on Adolescent Developmental Competence  

ERIC Educational Resources Information Center

The aim of this study is to assess the impact of sudden parental bereavement on subsequent attainment of developmental competencies. This longitudinal study reports on 126 youth bereaved by sudden parental death (suicide, accident, or natural death) and 116 demographically similar nonbereaved controls assessed at 9, 21, 33, and 62 months after…

Brent, David A.; Melhem, Nadine M.; Masten, Ann S.; Porta, Giovanna; Walker Payne, Monica

2012-01-01

361

Longitudinal Relationships between Core Self-Evaluations and Job Satisfaction  

ERIC Educational Resources Information Center

Core self-evaluations (CSE) have been proposed as a static personality trait that influences individuals' work experiences. However, CSE can also be influenced by work experiences. Based on the corresponsive principle of personality development, this study incorporated both dispositional and contextual perspectives to examine longitudinal

Wu, Chia-Huei; Griffin, Mark A.

2012-01-01

362

Neuronal excitation, inhibition and modulation of leech longitudinal muscle  

Microsoft Academic Search

The effects of impulse activity in identified excitatory motor neurons, inhibitory motor neurons and Retzius cells upon mechanical properties of the longitudinal muscle of the leechHirudo medicinalis were examined.1.Contractions produced by different exciters differed in their rates of rise and peak tensions. Each excitor had a different minimum firing rate required to produce a detectable contraction and each had a

Adrian Mason; William B. Kristan

1982-01-01

363

Longitudinal elastic behavior of the mixed ferroelectric KTN  

Microsoft Academic Search

Because of the essential role played by anharmonic elastic forces and strain in ferroelectric transitions, elastic measurements can provide direct evidence of the various stages which ferroelectrics go through when approaching the transition. In the case of mixed ferroelectrics like KTN, the transition occurs in two distinct stages, clearly revealed by ultrasonic measurements of the longitudinal C11 elastic constant. In

X. M. Wang; J. Toulouse; L. A. Boatner

1990-01-01

364

Longitudinal Stability of Phonological and Surface Subtypes of Developmental Dyslexia  

ERIC Educational Resources Information Center

Limited evidence supports the external validity of the distinction between developmental phonological and surface dyslexia. We previously identified children ages 8 to 13 meeting criteria for these subtypes (Peterson, Pennington, & Olson, 2013) and now report on their reading and related skills approximately 5 years later. Longitudinal

Peterson, Robin L.; Pennington, Bruce F.; Olson, Richard K.; Wadsworth, Sally J.

2014-01-01

365

Measurement and simulation of the RHIC abort kicker longitudinal impedence  

SciTech Connect

In face of the new upgrades for RHIC the longitudinal impedance of the machine plays an important role in setting the threshold for instabilities and the efficacy of some systems. In this paper we describe the measurement of the longitudinal impedance of the abort kicker for RHIC as well as computer simulations of the structure. The impedance measurement was done by the S{sub 21} wire method covering the frequency range from 9 kHz to 2.5 GHz. We observed a sharp resonance peak around 10 MHz and a broader peak around 20 MHz in both, the real and imaginary part, of the Z/n. These two peaks account for a maximum imaginary longitudinal impedance of j15 {Omega}, a value an order of magnitude larger than the estimated value of j0.2 {Omega}, which indicates that the kicker is one of the main sources of longitudinal impedance in the machine. A computer model was constructed for simulations in the CST MWS program. Results for the magnet input and the also the beam impedance are compared to the measurements. A more detail study of the system properties and possible changes to reduce the coupling impedance are presented.

Abreu,N.P.; Hahn,H.; Choi, E.

2009-09-01

366

Regional ux analysis of longitudinal atrophy in Alzheimer's disease.  

E-print Network

Regional ux analysis of longitudinal atrophy in Alzheimer's disease. Lorenzi Marco1,2 , Nicholas Ayache1 , Xavier Pennec1 , and the Alzheimer's Disease Neuroimaging Initiative 1 Project Team Asclepios analysis of the brain morphology in Alzheimer's disease(AD) is fundamental for understanding

Paris-Sud XI, Université de

367

Pain Perceptions of the Oldest Old: A Longitudinal Study  

ERIC Educational Resources Information Center

Purpose: This study assessed self-reported pain in the oldest old and examined its changes over time and in relation to other measures of health and functioning. Design and Methods: A population-based sample of the oldest old (86-92 years of age) residing in Sweden who were participating in a multiwave longitudinal investigation were interviewed…

Zarit, Steven H.; Griffiths, Patricia C.; Berg, Stig

2004-01-01

368

Reciprocal Longitudinal Relations between Nonresident Father Involvement and Adolescent Delinquency  

ERIC Educational Resources Information Center

Using a representative sample of low-income, primarily minority adolescents (N=647, aged 10-14 years at Wave 1), this study examined bidirectional longitudinal relations between nonresident father involvement, defined as contact and responsibility for children's care and behavior, and adolescent engagement in delinquent activities. Autoregressive…

Coley, Rebekah Levine; Medeiros, Bethany L.

2007-01-01

369

Longitudinal Factor Score Estimation Using the Kalman Filter.  

ERIC Educational Resources Information Center

How longitudinal factor score estimation--the estimation of the evolution of factor scores for individual examinees over time--can profit from the Kalman filter technique is described. The Kalman estimates change more cautiously over time, have lower estimation error variances, and reproduce the LISREL program latent state correlations more…

Oud, Johan H.; And Others

1990-01-01

370

Adolescent Drug Use and Psychological Health: A Longitudinal Inquiry  

Microsoft Academic Search

The relation between psychological characteristics and drug use was investigated in subjects studied longitudinally, from preschool through age 18. Adolescents who had engaged in some drug experimentation (primarily with marijuana) were the best-adjusted in the sample. Adolescents who used drugs frequently were maladjusted, showing a distinct personality syndrome marked by interpersonal alienation, poor impulse control, and manifest emotional distress. Adolescents

Jonathan Shedler; Jack Block

1990-01-01

371

Longitudinal Rasch Modeling in the Context of Psychotherapy Outcomes Assessment  

ERIC Educational Resources Information Center

The present study illustrates an extension of Kamata's (2001) restricted form of the hierarchical generalized linear model that provides a multilevel longitudinal Rasch measurement model appropriate for use with polytomous responses. This extension can be used to assess average and interindividual change in the latent trait of interest,…

Pastor, Dena A.; Beretvas, S. Natasha

2006-01-01

372

Leveraging ARRA Funding for Developing Comprehensive State Longitudinal Data Systems  

ERIC Educational Resources Information Center

The American Recovery and Reinvestment Act (ARRA) provides several funding opportunities that can assist states in designing, developing, and implementing statewide education longitudinal data systems. These new and enhanced information systems will enable states to track student progress within and across the secondary and postsecondary education…

Pfeiffer, Jay; Klein, Steven; Levesque, Karen

2009-01-01

373

9. Photograph of a line drawing. SHEET 9, LONGITUDINAL SECTION ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Photograph of a line drawing. SHEET 9, LONGITUDINAL SECTION ON LINE AA; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

374

Longitudinal Magnetoacoustic Phenomena in Degenerate Semiconductors and Semimetals  

Microsoft Academic Search

The effects of parabolic and nonparabolic band structures on the propagation of ultrasound in a degenerate semiconductor like SrTiO3 in the presence of a dc longitudinal magnetic field are investigated. The major interaction between the conduction electrons and the ultrasound is via deformation potential coupling. It is found that the absorption coefficient and sound velocity for ultrasound propagating parallel to

Chhi-Chong Wu; Jensan Tsai

1972-01-01

375

Longitudinal Links between Early Coparenting and Infant Behaviour Problems  

ERIC Educational Resources Information Center

This study of 164 married couples examined longitudinal links between parents' perceptions of coparenting support and undermining by spouse at 6 months postpartum and infant behaviour problems at the age of 12 months after controlling for marital quality, individual parenting, and infant temperament. Multiple methods (i.e. parent reports and…

LeRoy, Michelle; Mahoney, Annette; Pargament, Kenneth I.; DeMaris, Alfred

2013-01-01

376

Longitudinal phonetic variation in a closed system University of Chicago  

E-print Network

Longitudinal phonetic variation in a closed system Max Bane University of Chicago Peter Graff MIT-scale corpus study of the trajectories of different phonetic parameters over the course of three months offers a unique opportunity to study "medium term" phonetic change in individuals: longer than studies

Stephens, Matthew

377

Parental Influences on Young People's Sexual Behaviour: A Longitudinal Analysis  

ERIC Educational Resources Information Center

Both family structure and processes have been associated with young people's sexual behaviour, but most studies are cross-sectional and focus on only one outcome: age at first intercourse. This paper uses longitudinal data from a survey of Scottish teenagers (N=5041) to show how low parental monitoring predicts early sexual activity for both sexes…

Wight, Daniel; Williamson, Lisa; Henderson, Marion

2006-01-01

378

Nonlinear Latent Curve Models for Multivariate Longitudinal Data  

ERIC Educational Resources Information Center

Latent curve models have become a useful approach to analyzing longitudinal data, due in part to their allowance of and emphasis on individual differences in features that describe change. Common applications of latent curve models in developmental studies rely on polynomial functions, such as linear or quadratic functions. Although useful for…

Blozis, Shelley A.; Conger, Katherine J.; Harring, Jeffrey R.

2007-01-01

379

Stability of Career Aspirations: A Longitudinal Test of Gottfredson's Theory  

ERIC Educational Resources Information Center

Gottfredson's theory of the career compromise process was evaluated using a longitudinal data set of 2,353 female and 321 male students recruited for Zuckerman's "Seven College Study," who reported their career aspirations twice over a 1-year period. Expressed career aspirations were coded on the dimensions of sex type, prestige, and the…

Junk, Kate E.; Armstrong, Patrick Ian

2010-01-01

380

A Longitudinal Study of School Districts' Sustained Improvement  

ERIC Educational Resources Information Center

In this longitudinal study of one region in the state of Texas, there was an examination of district leadership and the sustaining of high student achievement for their districts. The results of this study suggest that sustained improvement of student achievement is very difficult. The districts that had sustained improvement had stable district…

Sampson, Pauline M.

2011-01-01

381

The Generalized Multilevel Facets Model for Longitudinal Data  

ERIC Educational Resources Information Center

In the human sciences, ability tests or psychological inventories are often repeatedly conducted to measure growth. Standard item response models do not take into account possible autocorrelation in longitudinal data. In this study, the authors propose an item response model to account for autocorrelation. The proposed three-level model consists…

Hung, Lai-Fa; Wang, Wen-Chung

2012-01-01

382

GASTROINTESTINAL ANATOMY Fig. 171. Longitudinal section through the liver  

E-print Network

GASTROINTESTINAL ANATOMY Fig. 171. Longitudinal section through the liver and gallbladder gallbladder gallbladder bile duct ampulla of Vater (bile duct papilla) duodenum pylorus duodenum The Anatomy of Sea Turtles 113 #12;The Anatomy of Sea Turtles114 GASTROINTESTINAL ANATOMY Figs. 172a and 172b

383

Predictors of Longitudinal Growth in Inhibitory Control in Early Childhood  

ERIC Educational Resources Information Center

In the current study, we examined latent growth in 731 young children's inhibitory control from the ages of two to four years, and whether demographic characteristics or parenting behaviors were related to initial levels and growth in inhibitory control. As part of an ongoing longitudinal evaluation of the family check-up, children's inhibitory…

Moilanen, Kristin L.; Shaw, Daniel S.; Dishion, Thomas J.; Gardner, Frances; Wilson, Melvin

2010-01-01

384

LONGITUDINAL OSCILLATIONS IN DENSITY STRATIFIED AND EXPANDING SOLAR WAVEGUIDES  

SciTech Connect

Waves and oscillations can provide vital information about the internal structure of waveguides in which they propagate. Here, we analytically investigate the effects of density and magnetic stratification on linear longitudinal magnetohydrodynamic (MHD) waves. The focus of this paper is to study the eigenmodes of these oscillations. It is our specific aim to understand what happens to these MHD waves generated in flux tubes with non-constant (e.g., expanding or magnetic bottle) cross-sectional area and density variations. The governing equation of the longitudinal mode is derived and solved analytically and numerically. In particular, the limit of the thin flux tube approximation is examined. The general solution describing the slow longitudinal MHD waves in an expanding magnetic flux tube with constant density is found. Longitudinal MHD waves in density stratified loops with constant magnetic field are also analyzed. From analytical solutions, the frequency ratio of the first overtone and fundamental mode is investigated in stratified waveguides. For small expansion, a linear dependence between the frequency ratio and the expansion factor is found. From numerical calculations it was found that the frequency ratio strongly depends on the density profile chosen and, in general, the numerical results are in agreement with the analytical results. The relevance of these results for solar magneto-seismology is discussed.

Luna-Cardozo, M. [Instituto de Astronomia y Fisica del Espacio, CONICET-UBA, CC. 67, Suc. 28, 1428 Buenos Aires (Argentina); Verth, G. [School of Computing, Engineering and Information Sciences, Northumbria University, Newcastle Upon Tyne NE1 8ST (United Kingdom); Erdelyi, R., E-mail: mluna@iafe.uba.ar, E-mail: robertus@sheffield.ac.uk, E-mail: gary.verth@northumbria.ac.uk [Solar Physics and Space Plasma Research Centre (SP2RC), University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2012-04-01

385

A Longitudinal Study of the Correlates of Children's Social Behavior.  

ERIC Educational Resources Information Center

Reported was an 8 year longitudinal study of social and antisocial behavioral correlates in 1550 third, sixth, and ninth grade children identified as either aggressive-disruptive or prosocial by their teachers. A more intensive study was made of 192 aggressive-disruptive and 192 prosocial children. Data included interviews, individual tests (such…

Feldhusen, John F.; And Others

386

AIAA 2004-4162 Nonlinear Longitudinal Mode Instability in  

E-print Network

AIAA 2004-4162 Nonlinear Longitudinal Mode Instability in Liquid Propellant Rocket Engine Institute For permission to copy or republish, contact the copyright owner named on the first page. For AIAA-held copyright, write to AIAA, Permissions Department, 1801 Alexander Bell Drive, Suite 500, Reston, VA 20191

Flandro, Gary A.

387

Regression Artifacts in Time-Series and Longitudinal Data.  

ERIC Educational Resources Information Center

Regression artifacts are a source of mistaken causal inference in inferences based on time-series data and from longitudinal studies. These artifacts are illustrated, and it is noted that their magnitude is computable (and distinguishable from genuine effects) if the autocorrelation patterns for various lags is known. (SLD)

Campbell, Donald T.

1996-01-01

388

A Longitudinal Study of the Impact of an Environmental Action  

ERIC Educational Resources Information Center

In a previous study, we investigated the impact of an awareness-raising campaign on the behaviour of secondary school children in the Centre Region of France, regarding the recycling of used batteries. But, was it a question of pro-environmental behaviour or simply an environmental action? To answer this question, a three-year longitudinal study…

Rioux, Liliane; Pasquier, Daniel

2013-01-01

389

A longitudinal study on internship effectiveness in vocational higher education  

Microsoft Academic Search

A cooperative education experience (or internship placement) is an essential component of the curricula of vocational higher education. The efficacy of internship placements has become one of the major concerns facing those who develop education curricula. The purpose of this longitudinal study was to explore the relationships among the multi-faceted predictors of intern commitment as a reflection of internship efficacy.

Chin-Sheng Wan; Jen-te Yang; Shu-yun Cheng; Chiakai Su

2011-01-01

390

First Results of the LHC Longitudinal Density Monitor  

SciTech Connect

The Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. It is designed to accelerate and collide protons or heavy ions up to the center-of-mass energies of 14 TeV. Knowledge of the longitudinal distribution of particles is important for various aspects of accelerator operation, in particular to check the injection quality and to measure the proportion of charge outside the nominally filled bunches during the physics periods. In order to study this so-called ghost charge at levels very much smaller than the main bunches, a longitudinal profile measurement with a very high dynamic range is needed. A new detector, the LHC Longitudinal Density Monitor (LDM) is a single-photon counting system measuring synchrotron light by means of an avalanche photodiode detector. The unprecedented energies reached in the LHC allow synchrotron light diagnostics to be used with both protons and heavy ions. A prototype was installed during the 2010 LHC run and was able to longitudinally profile the whole ring with a resolution close to the target of 50 ps. On-line correction for the effects of the detector deadtime, pile-up and afterpulsing allow a dynamic range of 105 to be achieved. First measurements with the LDM are presented here along with an analysis of its performance and an outlook for future upgrades.

Jeff, A.; /CERN /Liverpool U.; Boccardi, A.; /CERN; Bravin, E.; /CERN; Fisher, A.S.; /SLAC; Lefevre, T.; /CERN; Rabiller, A.; /CERN; Roncarolo, F.; /CERN; Welsch, C.P.; /Liverpool U. /Cockcroft Inst. Accel. Sci. Tech.

2012-04-19

391

NATIONAL LONGITUDINAL MORTALITY STUDY- NATIONAL DEATH INDEX RECORD LINKAGE (NLMS)  

EPA Science Inventory

National Longitudinal Mortality Study is to investigate social, economic, demographic and occupational differentials in mortality (total and by cause) within a national sample of the U.S. population. In a collaboration begun in 1999 with the Census Bureau and other federal agenci...

392

A Bayesian Shrinkage Model for Incomplete Longitudinal Binary Data  

E-print Network

inference in randomized longitudinal studies with missing data that is generated by skipped clinic visits and loss to follow-up. In this setting, it is well known that full data estimands are not identified unless population of the study was women at increased risk of developing breast cancer, including women who were age

Daniels, Michael J.

393

Component vs Factor Analytic Approaches to Longitudinal Data.  

ERIC Educational Resources Information Center

A component analytic method for analyzing multivariate longitudinal data is presented that does not make strong assumptions about the structure of the data. Central to the method are the facts that components are derived as linear composites of the observed or manifest variables and that the components must provide an adequate representation of…

Millsap, Roger E.

394

Longitudinal study of symptoms and cognitive function in chronic schizophrenia  

Microsoft Academic Search

There is conflicting evidence of a relationship between changes in symptoms and cognitive functioning in schizophrenia. This study investigated longitudinal changes in psychopathology and cognitive functioning in chronic schizophrenia utilising three different dimensional models of symptomatology. Sixty-two patients diagnosed with DSM-IV schizophrenia or schizoaffective disorder were examined on two occasions over a period of 6 months for symptom improvement, measured

Catherine Hughes; Veena Kumari; William Soni; Mrigendra Das; Brendon Binneman; Sonia Drozd; Shaun O'Neil; Vallakalil Mathew; Tonmoy Sharma

2003-01-01

395

Longitudinal Construct Validity of Brief Symptom Inventory Subscales in Schizophrenia  

ERIC Educational Resources Information Center

Longitudinal validity of Brief Symptom Inventory subscales was examined in a sample (N = 318) with schizophrenia-related illness measured at baseline and every 6 months for 3 years. Nonlinear factor analysis of items was used to test graded response models (GRMs) for subscales in isolation. The models varied in their within-time and between-times…

Long, Jeffrey D.; Harring, Jeffrey R.; Brekke, John S.; Test, Mary Ann; Greenberg, Jan

2007-01-01

396

Discovery of an Important Previously Unknown Longitudinal Wave  

Microsoft Academic Search

In 1988 a new species of longitudinal sound like wave was identified in this laboratory. These waves travel through (dark matter filled) vacuum as well as through ordinary matter. So far as is known these waves always appear as standing waves. The data suggest that they organize plants, organize structures in manipulated granular materials, organize planetary systems, and other structures

Orvin Wagner

2002-01-01

397

Discovery of an All-Pervading Previously Unknown Longitudinal Wave  

Microsoft Academic Search

In 1988 a new species of longitudinal sound like wave was identified in this laboratory. These waves travel through (dark matter filled) vacuum as well as through ordinary matter. So far as is known these waves always appear as standing waves. The data suggest that they organize plants, organize structures in manipulated granular materials, organize planetary systems, and other structures

Orvin E. Wagner

2002-01-01

398

Longitudinal control of automated CHVs with significant actuator delays  

Microsoft Academic Search

One of the most critical obstacles in the automated operation of commercial heavy vehicles (CHVs) is the presence of significant delays in the fuel and brake actuators. These delays are especially important in longitudinal control of vehicle platoons which do not employ intervehicle communication, because their effect becomes cumulative as it propagates upstream, resulting in considerably degraded performance. Our objective

Diana Yanakiev; Ioannis Kanellakopoulos

1997-01-01

399

Two-Method Planned Missing Designs for Longitudinal Research  

ERIC Educational Resources Information Center

We examine longitudinal extensions of the two-method measurement design, which uses planned missingness to optimize cost-efficiency and validity of hard-to-measure constructs. These designs use a combination of two measures: a "gold standard" that is highly valid but expensive to administer, and an inexpensive (e.g., survey-based)…

Garnier-Villarreal, Mauricio; Rhemtulla, Mijke; Little, Todd D.

2014-01-01

400

Varying Coefficient Models for Sparse Noise-contaminated Longitudinal Data  

PubMed Central

Summary In this paper we propose a varying coefficient model for highly sparse longitudinal data that allows for error-prone time-dependent variables and time-invariant covariates. We develop a new estimation procedure, based on covariance representation techniques, that enables effective borrowing of information across all subjects in sparse and irregular longitudinal data observed with measurement error, a challenge in which there is no adequate solution currently. More specifically, sparsity is addressed via a functional analysis approach that considers the observed longitudinal data as noise contaminated realizations of a random process that produces smooth trajectories. This approach allows for estimation based on pooled data, borrowing strength from all subjects, in targeting the mean functions and auto- and cross-covariances to overcome sparse noisy designs. The resulting estimators are shown to be uniformly consistent. Consistent prediction for the response trajectories are also obtained via conditional expectation under Gaussian assumptions. Asymptotic distribution of the predicted response trajectories are derived, allowing for construction of asymptotic pointwise confidence bands. Efficacy of the proposed method is investigated in simulation studies and compared to the commonly used local polynomial smoothing method. The proposed method is illustrated with a sparse longitudinal data set, examining the age-varying relationship between calcium absorption and dietary calcium. Prediction of individual calcium absorption curves as a function of age are also examined.

2014-01-01

401

Spatial variation of the longitudinal dispersion coefficient in an estuary  

NASA Astrophysics Data System (ADS)

The effective longitudinal dispersion is a primary tool for determining property distributions in estuaries. Most previous studies have examined the longitudinal dispersion coefficient for the average tidal condition. However, information on spatial and temporal variations of this coefficient at low and high tide is scarce. Three years of hydrographic data taken at low and high tide along the main axis of the Sumjin River Estuary (SRE), Korea are used to estimate the spatial and temporal variation of the effective longitudinal dispersion coefficient. The range of the dispersion coefficient is rather broad at high water slack (HWS) and narrower at low water slack (LWS) because of the different tidal amplitudes. The spatially varying dispersion coefficient has maximal values (>300 m2 s-1) near the mouth at high water and decreases gradually upstream, with fluctuations. The temporally varying dispersion coefficient appears to be positively correlated with river discharges at both low and high tide. The dispersion varies with the square root of river discharges at HWS and LWS. The dispersive salt fluxes increases with increasing river discharges and decreases with decreasing river discharges at HWS and LWS. Estimation of the numerical values of the effective longitudinal dispersion coefficient in the SRE can be useful for better understanding of the distributions of other tracers in the SRE as well as for developing and testing hypotheses about various mixing mechanisms.

Shaha, D. C.; Cho, Y.-K.; Kwak, M.-T.; Kundu, S. R.; Jung, K. T.

2011-08-01

402

Spatial variation of the longitudinal dispersion coefficient in an estuary  

NASA Astrophysics Data System (ADS)

The effective longitudinal dispersion is a primary tool for determining property distributions in estuaries. Most previous studies have examined the longitudinal dispersion coefficient for the average tidal condition. However, information on spatial and temporal variations of this coefficient at low and high tides is scarce. Three years of hydrographic data taken at low and high tide along the main axis of the Sumjin River Estuary (SRE), Korea are used to estimate the spatial and temporal variation of the effective longitudinal dispersion coefficient. The range of the dispersion coefficient is rather broad at high water slack (HWS) and narrower at low water slack (LWS) because of the different tidal amplitudes. The spatially varying dispersion coefficient has maximal values (>300 m2 s-1) near the mouth at high water and decreases gradually upstream, with fluctuations. The temporally varying dispersion coefficient appears to be positively correlated with river discharges at both low and high tide. The dispersion varies with the square root of river discharges at HWS and LWS. The dispersive salt fluxes increases with increasing river discharges and decreases with decreasing river discharges at HWS and LWS. Estimation of the numerical values of the effective longitudinal dispersion coefficient in the SRE can be useful for better understanding of the distributions of other tracers in the SRE as well as for developing and testing hypotheses about various mixing mechanisms.

Shaha, D. C.; Cho, Y.-K.; Kwak, M.-T.; Kundu, S. R.; Jung, K. T.

2011-12-01

403

TWO-STAGE EMPIRICAL LIKELIHOOD FOR LONGITUDINAL NEUROIMAGING DATA *  

PubMed Central

Longitudinal imaging studies are essential to understanding the neural development of neuropsychiatric disorders, substance use disorders, and the normal brain. The main objective of this paper is to develop a two-stage adjusted exponentially tilted empirical likelihood (TAETEL) for the spatial analysis of neuroimaging data from longitudinal studies. The TAETEL method allows us to efficiently analyze longitudinal data without correctly modeling temporal correlation and to classify different time-dependent covariate types. To account for spatial dependence, the TAETEL method developed here specifically combines all the data in the neighborhood of each voxel (or pixel) on a 3 dimensional (3D) volume (or 2D surface) with appropriate weights to calculate adaptive parameter estimates and adaptive test statistics. Simulation studies are used to examine the finite sample performance of the adjusted exponential tilted likelihood ratio statistic and TAETEL. We demonstrate the application of our statistical methods to the detection of the difference in the morphological changes of the hippocampus across time between schizophrenia patients and healthy subjects in a longitudinal schizophrenia study. PMID:21765885

Shi, Xiaoyan; Ibrahim, Joseph G.; Lieberman, Jeffrey; Styner, Martin; Zhu, Hongtu

2011-01-01

404

Geological and plate tectonic setting of the Longitudinal Valley  

E-print Network

3 Chapter 1 Geological and plate tectonic setting of the Longitudinal Valley Fault 1.1 Tectonic and the Philippine Sea Plate (Figure 1.1a). South of Taiwan this convergence is absorbed along the Manila trench by the eastward subduction of the oceanic crust of the South China Sea beneath the Philippine Sea Plate, leading

Winfree, Erik

405

Nanofocusing of longitudinally polarized light using absorbance modulation  

SciTech Connect

Recently, many methods based on amplitude or phase modulation to reduce the focal spot and enhance the longitudinal field component of a tight-focused radially polarized light beam have been suggested. But they all suffer from spot size limit 0.36?/NA and large side lobes strength in longitudinal component. Here, we report a method of generating a tighter focused spot by focusing radially polarized and azimuthally polarized beams of different wavelengths on a thin photochromic film through a high-numerical-aperture lens simultaneously. In this method, by suppressing the radial component and compressing the longitudinal component of radially polarized beam, absorbance modulation makes the ultimate spot size break the size limit of 0.36?/NA with side-lobe intensity of longitudinal component below 1% of central-peak intensity. The theoretical analysis and simulation demonstrate that the focal spot size could be smaller than 0.1? with nearly all radial component blocked at high intensity ratio of the two illuminating beams.

Li, Qiang; Zhao, Xing, E-mail: zhaoxingtjnk@nankai.edu.cn; Zhang, Bo; Zheng, Yi; Zhou, Liqiu; Fang, Zhiliang [Institute of Modern Optics, Key Laboratory of Optical Information Science and Technology, Ministry of Education of China, Nankai University, Tianjin 300071 (China); Wang, Lingjie; Wu, Yanxiong [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

2014-02-10

406

A Bayesian Approach for Analyzing Longitudinal Structural Equation Models  

ERIC Educational Resources Information Center

This article considers a Bayesian approach for analyzing a longitudinal 2-level nonlinear structural equation model with covariates, and mixed continuous and ordered categorical variables. The first-level model is formulated for measures taken at each time point nested within individuals for investigating their characteristics that are dynamically…

Song, Xin-Yuan; Lu, Zhao-Hua; Hser, Yih-Ing; Lee, Sik-Yum

2011-01-01

407

Longitudinal Intensity Normalization of Magnetic Resonance Images using Patches  

PubMed Central

This paper presents a patch based method to normalize temporal intensities from longitudinal brain magnetic resonance (MR) images. Longitudinal intensity normalization is relevant for subsequent processing, such as segmentation, so that rates of change of tissue volumes, cortical thickness, or shapes of brain structures becomes stable and smooth over time. Instead of using intensities at each voxel, we use patches as image features as a patch encodes neighborhood information of the center voxel. Once all the time-points of a longitudinal dataset are registered, the longitudinal intensity change at each patch is assumed to follow an auto-regressive (AR(1)) process. An estimate of the normalized intensities of a patch at every time-point are generated from a hidden Markov model, where the hidden states are the unobserved normalized patches and the outputs are the observed patches. A validation study on a phantom dataset shows good segmentation overlap with the truth, and an experiment with real data shows more stable rates of change for tissue volumes with the temporal normalization than without. PMID:24382991

Roy, Snehashis; Carass, Aaron; Prince, Jerry L.

2013-01-01

408

SYLLABUS : Spring, 2010 STATISTICS 689 : Missing Data in Longitudinal Studies  

E-print Network

/Hierarchical Models. A. Gelman and J. Hill (2008), Cambridge Press. 3. (Recommended) Mixed Effects Models for Complex to the theory and methods of longitudinal (repeated measures, panel,) data analysis with a focus on handling on regression models or generalized linear models( GLMs) with correlated response, and introducing the basic

Pourahmadi, Mohsen

409

Functional Modeling of Longitudinal Data Hans-Georg Muller  

E-print Network

such as the Generalized Linear Mixed Model (GLMM) or are marginal methods such as Generalized Esti- mating Equations (GEE of functional data analysis are smoothing, functional principal components, functional linear models and time Introduction Longitudinal studies are characterized by data records containing repeated measurements per

Müller, Hans-Georg

410

Mixed models for longitudinal left-censored repeated measures  

Microsoft Academic Search

Longitudinal studies could be complicated by left-censored repeated measures. For example, in Human Immunodeficiency Virus infection, there is a detection limit of the assay used to quantify the plasma viral load. Simple imputation of the limit of the detection or of half of this limit for left-censored measures biases estimations and their standard errors. In this paper, we review two

Rodolphe Thiébaut; Hélène Jacqmin-Gadda

2007-01-01

411

Mixed models for longitudinal left-censored repeated measures  

Microsoft Academic Search

Abstract Longitudinal studies could be complicated by left-censored repeated measures. For example, in Human Immunodeficiency Virus infection, there is a detection limit of the assay used to quantify the plasma viral load. Simple imputation of the limit of the detection or of half of this limit for left-censored measures biases estimations and their standard errors. In this paper, we review

Rodolphe Thiébaut; Hélène Jacqmin-gadda

2004-01-01

412

Social Class Differentiation in Cognitive Development: A Longitudinal Study.  

ERIC Educational Resources Information Center

In an effort to isolate the emergence and causes of social class differences in intellectual performance, this longitudinal study was undertaken as a follow-up on a cross-sectional study that yielded no social class differences on the Cattell Infant Intelligence Scale for 12-, 18-, and 24-month-old black children. In the present study, 89 children…

Golden, Mark; And Others

413

Using Longitudinal Scales Assessment for Instrumental Music Students  

ERIC Educational Resources Information Center

In music education, current assessment trends emphasize student reflection, tracking progress over time, and formative as well as summative measures. This view of assessment requires instrumental music educators to modernize their approaches without interfering with methods that have proven to be successful. To this end, the Longitudinal Scales…

Simon, Samuel H.

2014-01-01

414

Parental influences on adolescent physical activity: a longitudinal study  

Microsoft Academic Search

BACKGROUND: Physical inactivity is increasing among adolescents in the U.S., especially among girls. Despite growing evidence that parents are an important influence on adolescent health, few longitudinal studies have explored the causal relationship between parental influence and physical activity. This study examines how the relationships between parental influences and adolescent physical activity differ by gender and tests whether these relationships

India J Ornelas; Krista M Perreira; Guadalupe X Ayala

2007-01-01

415

Violence Viewing and Adolescent Aggression: A Longitudinal Study.  

ERIC Educational Resources Information Center

A longitudinal field study conducted in Turku, Finland, traced the development of aggression as a function of the viewing of violence by children from the ages of 7 and 9 to the ages of 15 and 17 to explore the connection between violence viewing and viewers' aggression, and to shed light on the question of causality. The 220 subjects, both male…

Viemero, Vappu

416

Attachment from Infancy to Adulthood: The Major Longitudinal Studies  

ERIC Educational Resources Information Center

This volume provides unique and valuable firsthand accounts of the most important longitudinal studies of attachment. Presented are a range of research programs that have broadened the understanding of early close relationships and their role in individual adaptation throughout life. In addition to discussing the findings that emerged from each…

Grossmann, Klaus E., Ed.; Grossmann, Karin, Ed.; Waters, Everett, Ed.

2005-01-01

417

Longitudinal Study of Low and High Achievers in Early Mathematics  

ERIC Educational Resources Information Center

Background: Longitudinal studies allow us to identify, which specific maths skills are weak in young children, and whether there is a continuing weakness in these areas throughout their school years. Aims: This 2-year study investigated whether certain socio-demographic variables affect early mathematical competency in children aged 5-7 years.…

Navarro, Jose I.; Aguilar, Manuel; Marchena, Esperanza; Ruiz, Gonzalo; Menacho, Inmaculada; Van Luit, Johannes E. H.

2012-01-01

418

Homeschooling Education: Longitudinal Study of Methods, Materials, and Curricula  

ERIC Educational Resources Information Center

In a comprehensive study of two-hundred fifty homeschooling families in urban, rural and suburban areas of the Commonwealth of Pennsylvania, the researcher examined all aspects of the instruction, materials and curricula employed by the families in a ten-year longitudinal study from 1998 through 2008. The researcher conducted interviews and…

Hanna, Linda G.

2012-01-01

419

Effects of a Rape Experience: A Longitudinal Study.  

ERIC Educational Resources Information Center

A longitudinal study found that victims of rape are significantly more anxious, fearful, suspicious, and confused than nonvictims for at least a year after they were assaulted. However, there was improvement on those and on other measures of personality and emotional state over time. (Author/MJL)

Kilpatrick, Dean G.; And Others

1981-01-01

420

Criminal Victimization and Crime Risk Perception: A Multilevel Longitudinal Study  

ERIC Educational Resources Information Center

In a national sample of the Italian population, surveyed four times between October 2002 and January 2007 (N = 2,008), we performed a multilevel longitudinal study aimed at predicting the increase in crime risk perception as a function of three families of independent variables, respectively lying at the within individual level (direct…

Russo, Silvia; Roccato, Michele; Vieno, Alessio

2013-01-01

421

ORAL PRESENTATION Open Access Longitudinal monitoring of cardiac dysfunction  

E-print Network

of anomalies appearance associated to diet-induced obesity and insulin resistance in a 4 month longitudinal model of obesity and type 2 diabetes Inès Abdesselam1,2* , Thomas Troalen1 , Pauline Pepino1 , Anne, USA. 16-19 January 2014 Background Obesity consequences include type 2 diabetes and cardi- ovascular

Boyer, Edmond

422

Switching speed of longitudinal thin film recording media  

Microsoft Academic Search

Switching speed of longitudinal thin film recording media was studied using micromagnetic modeling. The dependence of the switching speed on the damping constant ? was investigated. It is shown that when ? is small (=0.01), even with instantaneously rising head field, the medium switching time can be as large as 2 ns, which is slow enough to have a significant

Hao Fang; Jian-Gang Zhu

1996-01-01

423

Transition noise properties in longitudinal thin-film media  

Microsoft Academic Search

Transition noise properties in longitudinal thin film media are studied by micromagnetic modeling. The mechanism for enhancement of transition noise at small bit intervals due to intertransition interaction is investigated. The noise dependence on the medium parameters, such as saturation magnetization and film thickness, is calculated. Reducing either the saturation magnetization or the film thickness yields a reduction of transition

Jian-Gang Zhu

1993-01-01

424

FIAS Longitudinal Measurements Modified - More Accurate Cotton Fiber Maturity  

Technology Transfer Automated Retrieval System (TEKTRAN)

A projected 2-D image of a cotton fiber has large variations in fiber width due to the convolutions along the longitudinal axes. The ratio of the maximum width to the minimum width of a fiber ribbon could be used as a maturity indicator. Another important factor related to cotton maturity is fibers ...

425

Maternal Psychosocial Adversity and the Longitudinal Development of Infant Sleep  

ERIC Educational Resources Information Center

Research has identified associations between indicators of social disadvantage and the presence of child sleep problems. We examined the longitudinal development of infant sleep in families experiencing high (n = 58) or low (n = 64) levels of psychosocial adversity, and the contributions of neonatal self-regulatory capacities and maternal settling…

Cronin, Alison; Halligan, Sarah L.; Murray, Lynne

2008-01-01

426

A Longitudinal Study on Internship Effectiveness in Vocational Higher Education  

ERIC Educational Resources Information Center

A cooperative education experience (or internship placement) is an essential component of the curricula of vocational higher education. The efficacy of internship placements has become one of the major concerns facing those who develop education curricula. The purpose of this longitudinal study was to explore the relationships among the…

Wan, Chin-Sheng; Yang, Jen-te; Cheng, Shu-yun; Su, Chiakai

2013-01-01

427

Longitudinal Study on Reciprocity between Personality Traits and Parenting Stress  

ERIC Educational Resources Information Center

Reciprocal associations between the Big Five personality traits and parenting stress--including both parents' feelings of their distress and perception of their incompetence as parents--were studied with 248 participants (49% of which were males). Longitudinal data, collected at ages 33/36, 42 and 50 years, were used. Cross-lagged path…

Rantanen, Johanna; Tillemann, Kati; Metsäpelto, Riitta-Leena; Kokko, Katja; Pulkkinen, Lea

2015-01-01

428

Longitudinal Dimensionality of Adolescent Psychopathology: Testing the Differentiation Hypothesis  

ERIC Educational Resources Information Center

Background: The differentiation hypothesis posits that the underlying liability distribution for psychopathology is of low dimensionality in young children, inflating diagnostic comorbidity rates, but increases in dimensionality with age as latent syndromes become less correlated. This hypothesis has not been adequately tested with longitudinal

Sterba, Sonya K.; Copeland, William; Egger, Helen L.; Costello, E. Jane; Erkanli, Alaattin; Angold, Adrian

2010-01-01

429

Measurement of the Longitudinal Structure Function in Diffraction  

E-print Network

Measurement of the Longitudinal Structure Function in Diffraction FL D David Sálek Institute Workshop 2009, Italy First Measurement of FLD 2 Diffractive Kinematics and Rapidity GapDiffractive Workshop 2009, Italy First Measurement of FLD 3 Proton Structure Functions in DiffractionProton Structure

430

Intimate Partner Violence and Welfare Participation: A Longitudinal Causal Analysis  

ERIC Educational Resources Information Center

This longitudinal study examined the temporal-ordered causal relationship between intimate partner violence (IPV), five mental disorders (depression, generalized anxiety disorder, social phobia, panic attack, posttraumatic stress disorder [PTSD]), alcohol abuse/dependence, drug abuse/ dependence, treatment seeking (from physician, counselor, and…

Cheng, Tyrone C.

2013-01-01

431

Theories, Methods and Case Studies of Longitudinal HCI Research  

E-print Network

in research on Human-Computer Interaction (HCI). However, recent market and legislation developments for the need of multi-year studies in assessing the effectiveness of technologies that motivate users to adopt Longitudinal studies have been traditionally seen as too cumbersome and labor-intensive to be of much use

Tomkins, Andrew

432

Ureter Smooth Muscle Cell Orientation in Rat Is Predominantly Longitudinal  

PubMed Central

In ureter peristalsis, the orientation of the contracting smooth muscle cells is essential, yet current descriptions of orientation and composition of the smooth muscle layer in human as well as in rat ureter are inconsistent. The present study aims to improve quantification of smooth muscle orientation in rat ureters as a basis for mechanistic understanding of peristalsis. A crucial step in our approach is to use two-photon laser scanning microscopy and image analysis providing objective, quantitative data on smooth muscle cell orientation in intact ureters, avoiding the usual sectioning artifacts. In 36 rat ureter segments, originating from a proximal, middle or distal site and from a left or right ureter, we found close to the adventitia a well-defined longitudinal smooth muscle orientation. Towards the lamina propria, the orientation gradually became slightly more disperse, yet the main orientation remained longitudinal. We conclude that smooth muscle cell orientation in rat ureter is predominantly longitudinal, though the orientation gradually becomes more disperse towards the proprial side. These findings do not support identification of separate layers. The observed longitudinal orientation suggests that smooth muscle contraction would rather cause local shortening of the ureter, than cause luminal constriction. However, the net-like connective tissue of the ureter wall may translate local longitudinal shortening into co-local luminal constriction, facilitating peristalsis. Our quantitative, minimally invasive approach is a crucial step towards more mechanistic insight into ureter peristalsis, and may also be used to study smooth muscle cell orientation in other tube-like structures like gut and blood vessels. PMID:24465961

Reesink, Koen D.; Kroon, Wilco; Delhaas, Tammo

2014-01-01

433

Longitudinal, Regional and Deformation-Specific Corpus Callosum Shape Analysis for Multiple Sclerosis  

E-print Network

brain scans of a group of multiple sclerosis patients undergoing a longitudinal (serial) study transmit neural impulses between the hemispheres. Multiple Sclerosis is an inflammatory and degenerativeLongitudinal, Regional and Deformation-Specific Corpus Callosum Shape Analysis for Multiple

Hamarneh, Ghassan

434

Edinburgh Research Explorer A longitudinal survey of African animal trypanosomiasis in  

E-print Network

Edinburgh Research Explorer A longitudinal survey of African animal trypanosomiasis in domestic trypanosomiasis in domestic cattle on the Jos Plateau, Nigeria: prevalence, distribution and risk factors. 2014 #12;RESEARCH Open Access A longitudinal survey of African animal trypanosomiasis in domestic

Millar, Andrew J.

435

Single-Longitudinal-Mode Lanthanum-Codoped Bismuth-Based Erbium Doped Fiber Ring Laser  

E-print Network

Single-Longitudinal-Mode Lanthanum-Codoped Bismuth-Based Erbium Doped Fiber Ring Laser K. K and demonstrate a stable single-longitudinal-mode lanthanum-codoped bismuth oxide- based erbium doped fiber ring

Wai, Ping-kong Alexander

436

Cross-Sectional and Longitudinal Relationships Among Age, Cognition, and Processing Speed  

Microsoft Academic Search

Cross-sectional and longitudinal age effects on cognitive function were examined in 302 older adults followed longitudinally. Processing speed was related to cognitive performance at cross-section, and change in speed predicted within-person longitudinal cognitive decline. Statistical control of processing speed greatly reduced cross-sectional age effects but did not attenuate longitudinal aging effects. This difference in processing speed's ability to account for

Martin Sliwinski; Herman Buschke

1999-01-01

437

Input Shaping for Continuum Beams under Longitudinal Vibration Joel Fortgang* and William Singhose**  

E-print Network

Fig. 2. Impulse Response of Longitudinal Beam End Point 0 0.5 1 1.5 1 0.5 0 0.5 0 0.5 Postion Along BeamTime Deflection Fig. 3. Impulse Response of Longitudinal Beam displacements, the rest of the beamInput Shaping for Continuum Beams under Longitudinal Vibration Joel Fortgang* and William Singhose

Singhose, William

438

The Latent Curve ARMA (P, Q) Panel Model: Longitudinal Data Analysis in Educational Research and Evaluation  

ERIC Educational Resources Information Center

Autocorrelated residuals in longitudinal data are widely reported as common to longitudinal data. Yet few, if any, researchers modeling growth processes evaluate a priori whether their data have this feature. Sivo, Fan, and Witta (2005) found that not modeling autocorrelated residuals present in longitudinal data severely biases latent curve…

Sivo, Stephen; Fan, Xitao

2008-01-01

439

Coping with Memory Effect and Serial Correlation when Estimating Reliability in a Longitudinal Framework  

ERIC Educational Resources Information Center

Longitudinal studies are permeating clinical trials in psychiatry. Therefore, it is of utmost importance to study the psychometric properties of rating scales, frequently used in these trials, within a longitudinal framework. However, intrasubject serial correlation and memory effects are problematic issues often encountered in longitudinal data.…

Laenen, Annouschka; Alonso, Ariel; Molenberghs, Geert; Vangeneugden, Tony; Mallinckrodt, Craig H.

2010-01-01

440

Longitudinal Data Analysis. A Comparison Between Generalized Estimating Equations and Random Coefficient Analysis  

Microsoft Academic Search

The analysis of data from longitudinal studies requires special techniques, which take into account the fact that the repeated measurements within one individual are correlated. In this paper, the two most commonly used techniques to analyze longitudinal data are compared: generalized estimating equations (GEE) and random coefficient analysis. Both techniques were used to analyze a longitudinal dataset with six measurements

Jos W. R. Twisk

2004-01-01

441

Academic Performance of Language-Minority Students and All-Day Kindergarten: A Longitudinal Study  

ERIC Educational Resources Information Center

This longitudinal study examined the effect of all-day kindergarten programs on the academic achievement of students from racial language minority and low socioeconomic class. The study employed a series of 3-level longitudinal multilevel analyses using a nationally representative database, the Early Childhood Longitudinal Study (ECLS). The study…

Chang, Mido

2012-01-01

442

Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1  

E-print Network

Longitudinally propagating arc wave in the pre-onset optical aurora V. M. Uritsky,1 J. Liang,1 E aurora ­ the longitudinally propagating arc wave (LPAW) ­ associated with flapping oscillations, and K. H. Glassmeier (2009), Longitudinally propagating arc wave in the pre-onset optical aurora

California at Berkeley, University of

443

Generation of longitudinal vibrations in piano strings: From physics to sound synthesis  

Microsoft Academic Search

Longitudinal vibration of piano strings greatly contributes to the distinctive character of low piano notes. In this paper a simplified modal model is developed, which describes the generation of phantom partials and longitudinal free modes jointly. The model is based on the simplification that the coupling from the transverse vibration to the longitudinal polarization is unidirectional. The modal formulation makes

Balázs Bank; La?szlo? Sujbert

2005-01-01

444

Longitudinal Models of Developmental Dynamics Between Reading and Cognition from Childhood to Adolescence  

ERIC Educational Resources Information Center

The authors applied linear dynamic models to longitudinal data to examine the dynamics of reading and cognition from 1st to 12th grade. They used longitudinal data (N=445) from the Connecticut Longitudinal Study (S. E. Shaywitz, B. A. Shaywitz, J. M. Fletcher, & M. D. Escobar, 1990) to map the dynamic interrelations of various scales of the…

Ferrer, Emilio; McArdle, John J.; Shaywitz, Bennett A.; Holahan, John M.; Marchione, Karen; Shaywitz, Sally E.

2007-01-01

445

Neural tube defects – recent advances, unsolved questions and controversies  

PubMed Central

Neural tube defects (NTDs) are severe congenital malformations affecting around 1 in every 1000 pregnancies. Here we review recent advances and currently unsolved issues in the NTD field. An innovation in clinical management has come from the demonstration that closure of open spina bifida lesions in utero can diminish neurological dysfunction in children. Primary prevention by folic acid has been enhanced through introduction of mandatory food fortification in some countries, although not yet in UK. Genetic predisposition comprises the majority of NTD risk, and genes that regulate folate one-carbon metabolism and planar cell polarity have been strongly implicated. The sequence of human neural tube closure events remains controversial, but study of mouse NTD models shows that anencephaly, open spina bifida and craniorachischisis result from failure of primary neurulation, while skin-covered spinal dysraphism results from defective secondary neurulation. Other ‘NTD’ malformations, such as encephalocele, are likely to be post-neurulation disorders. PMID:23790957

Copp, Andrew J.; Stanier, Philip; Greene, Nicholas D. E.

2014-01-01

446

Sprengel's deformity: association with musculoskeletal dysfunctions and tethered cord syndrome.  

PubMed

Sprengel's deformity is a rare and complex congenital deformity of the shoulder girdle. The deformity commonly occurs sporadically, though in combination with other congenital anomalies, such as congenital scoliosis, fusion of cervical vertebrae, and conditions like Klippel-Feil syndrome may coexist. We report a case of a 14-year-old girl with bilateral Sprengel's deformity presenting with a progressive bilateral lower limb weakness and gait abnormality. Radiological investigations demonstrated multiple musculoskeletal abnormalities on x-ray and lumbar spina bifida occulta causing tethering of the cord on MRI. The patient consulted neurosurgeons and orthopaedic surgeons, who recommended no operative intervention and conservative management till the end of growth spurt. Therefore, we prescribed a home-based exercise regimen to strengthen the periscapular and intrinsic foot muscles. Although rare, Sprengel's deformity can be associated with other musculoskeletal abnormalities including lumbar spina bifida and comprehensive neurological examination should not be ignored as it is much more than a cosmetic problem. PMID:23605835

Mittal, Nimish; Majumdar, Ritu; Chauhan, Sonal; Acharjya, Minati

2013-01-01

447

Neural stem cells: are they the hope of a better life for patients with fetal-onset hydrocephalus?  

PubMed Central

I was honored to be awarded the Casey Holter Essay Prize in 2013 by the Society for Research into Hydrocephalus and Spina Bifida. The purpose of the prize is to encourage original thinking in a way to improve the care of individuals with spina bifida and hydrocephalus. Having kept this purpose in mind, I have chosen the title: Neural stem cells, are they the hope of a better life for patients with fetal-onset hydrocephalus? The aim is to review and discuss some of the most recent and relevant findings regarding mechanisms leading to both hydrocephalus and abnormal neuro/gliogenesis. By looking at these outcome studies, it is hoped that we will recognize the potential use of neural stem cells in the treatment of hydrocephalus, and so prevent the disease or diminish/repair the associated brain damage. PMID:24685106

2014-01-01

448

GTF Transverse and Longitudinal Emittance Data Analysis Technique  

SciTech Connect

The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Measurements at the GTF include quadrupole scan transverse emittance measurements and linac phase scan longitudinal emittance measurements. Typically the beam size is measured on a screen as a function of a quadrupole current or linac phase and the beam matrix is then fit to the measured data. Often the emittance which is the final result of the measurement is the only number reported. However, the method used to reduce the data to the final emittance value can have a significant effect on the result. This paper describes in painful detail the methods used to analyze the transverse and longitudinal emittance data collected at the GTF.

Not Available

2010-12-07

449

Managing Endings in a Longitudinal Study: Respect for Persons  

NASA Astrophysics Data System (ADS)

In this paper I describe and discuss the way that a book I had written on a five-year longitudinal study of school science teaching was received by the pupils and teachers it featured. By and large the pupils' reception was positive. However, one group of teachers was deeply hurt by the book. I trace this mainly to my failure to consider adequately their fears of the consequences of the book's publication and possibly to my failure to consider with them the psychological significance of my withdrawing from the school after five years of regular study. I hope that there are lessons not only for myself but also for others considering longitudinal and ethnographic research in science education and more broadly.

Reiss, Michael J.

2005-03-01

450

Mapping genes with longitudinal phenotypes via Bayesian posterior probabilities  

PubMed Central

Most association studies focus on disease risk, with less attention paid to disease progression or severity. These phenotypes require longitudinal data. This paper presents a new method for analyzing longitudinal data to map genes in both population-based and family-based studies. Using simulated systolic blood pressure measurements obtained from Genetic Analysis Workshop 18, we cluster the phenotype data into trajectory subgroups. We then use the Bayesian posterior probability of being in the high subgroup as a quantitative trait in an association analysis with genotype data. This method maintains high power (>80%) in locating genes known to affect the simulated phenotype for most specified significance levels (?). We believe that this method can be useful to aid in the discovery of genes that affect severity or progression of disease. PMID:25519410

2014-01-01

451

Note: Longitudinally excited N2 laser with low beam divergence  

NASA Astrophysics Data System (ADS)

We developed a longitudinally excited N2 laser (337 nm) with low beam divergence without collimator lenses. The N2 laser consisted of a 30 cm long Pyrex glass tube with an inner diameter of 2.5 mm, a normal stable resonator formed by flat mirrors, and a simple, novel driver circuit. At a N2 gas pressure of 0.4 kPa and a repetition rate of 40 Hz, the N2 laser produced a circular beam with an output energy of 2.6 ?J and a low full-angle beam divergence of 0.29 mrad due to the uniform discharge formed by the longitudinal excitation scheme, the long cavity with the small aperture, and the low-input energy oscillation.

Uno, K.; Akitsu, T.; Jitsuno, T.

2014-09-01

452

Note: Longitudinally excited N? laser with low beam divergence.  

PubMed

We developed a longitudinally excited N2 laser (337 nm) with low beam divergence without collimator lenses. The N2 laser consisted of a 30 cm long Pyrex glass tube with an inner diameter of 2.5 mm, a normal stable resonator formed by flat mirrors, and a simple, novel driver circuit. At a N2 gas pressure of 0.4 kPa and a repetition rate of 40 Hz, the N2 laser produced a circular beam with an output energy of 2.6 ?J and a low full-angle beam divergence of 0.29 mrad due to the uniform discharge formed by the longitudinal excitation scheme, the long cavity with the small aperture, and the low-input energy oscillation. PMID:25273794

Uno, K; Akitsu, T; Jitsuno, T

2014-09-01

453

High-resolution, noninvasive longitudinal live imaging of immune responses  

PubMed Central

Intravital imaging emerged as an indispensible tool in biological research, and a variety of imaging techniques have been developed to noninvasively monitor tissues in vivo. However, most of the current techniques lack the resolution to study events at the single-cell level. Although intravital multiphoton microscopy has addressed this limitation, the need for repeated noninvasive access to the same tissue in longitudinal in vivo studies remains largely unmet. We now report on a previously unexplored approach to study immune responses after transplantation of pancreatic islets into the anterior chamber of the mouse eye. This approach enabled (i) longitudinal, noninvasive imaging of transplanted tissues in vivo; (ii) in vivo cytolabeling to assess cellular phenotype and viability in situ; (iii) local intervention by topical application or intraocular injection; and (iv) real-time tracking of infiltrating immune cells in the target tissue. PMID:21768391

Abdulreda, Midhat H.; Faleo, Gaetano; Molano, Ruth Damaris; Lopez-Cabezas, Maite; Molina, Judith; Tan, Yaohong; Echeverria, Oscar A. Ron; Zahr-Akrawi, Elsie; Rodriguez-Diaz, Rayner; Edlund, Patrick K.; Leibiger, Ingo; Bayer, Allison L.; Perez, Victor; Ricordi, Camillo; Caicedo, Alejandro; Pileggi, Antonello; Berggren, Per-Olof

2011-01-01

454

Longitudinal Plasma Resonance Shifts in Gold Nanoparticle Aggregates  

NASA Astrophysics Data System (ADS)

Recent interest in colloidal gold focuses on understanding the tunability of the longitudinal and transverse plasma resonance. It was reported that the reduction of HAuCl4 by Na2S produces gold nanoparticles with an optical absorption in the near infrared. This absorption blue shifts during the course of the reaction. X-ray photoemission spectroscopy (XPS) measurements on this system indicated that there was little sulfur present in the system. A small angle x-ray scattering (SAX) experiment was used to monitor the reaction while simultaneously the UV-VIS spectrum was measured. During the reaction the fractal dimension decreased from 4.154 +/- 0.850 to 0.624 +/- 0.146. The decrease in fractal dimension coincided with the blue shift in the longitudinal plasma resonance from the near IR to the visible. This suggests a change from reaction limited colloid aggregation (RLCA) to diffusion limited colloid aggregation (DLCA), caused the shift in the plasma resonance.

Norman, Thaddeus J., Jr.; Grant, Christian; Magana, Donny; Anderson, Roger W.; Zhang, Jin Z.; Cao, Daliang; Bridges, Frank; Liu, Jun; van Buuren, Tony

2002-11-01

455

Demonstration of a Horseshoe-Shaped Longitudinal Focal Profile  

SciTech Connect

The three-dimensional laser focal region has been spatially shaped so that in the focal plane the transverse intensity distribution is centrally peaked, whereas at multiple defocused planes along the laser propagation direction, the distribution is annular. The longitudinal profile of such a shaped laser focal volume is approximately in the form of a “horseshoe.” The horseshoe-shaped longitudinal profile was realized experimentally from a single laser beam by the incoherent coaxial combination of Laguerre–Gaussian and Gaussian modes generated from segmented optical elements. The ponderomotive forces associated with this three-dimensional focal intensity distribution can potentially generate a quasi-collimated, forward-directed bunch of electrons from a low-density gas target at high laser intensities.

Brijesh, P.; Kessler, T.J.; Zuegel, J.D.; Meyerhofer, D.D.

2007-03-26

456

Longitudinal alignment of disease progression in fibrosing interstitial lung disease.  

PubMed

Generating disease progression models from longitudinal medical imaging data is a challenging task due to the varying and often unknown state and speed of disease progression at the time of data acquisition, the limited number of scans and varying scanning intervals. We propose a method for temporally aligning imaging data from multiple patients driven by disease appearance. It aligns follow- up series of different patients in time, and creates a cross-sectional spatio-temporal disease pattern distribution model. Similarities in the disease distribution guide an optimization process, regularized by temporal rigidity and disease volume terms. We demonstrate the benefit of longitudinal alignment by classifying instances of different fibrosing interstitial lung diseases. Classification results (AUC) of Usual Interstitial Pneumonia (UIP) versus non-UIP improve from AUC = 0.71 to 0.78 following alignment, classification of UIP vs. Extrinsic Allergic Alveolitis (EAA) improves from 0.78 to 0.88. PMID:25485367

Vogl, Wolf-Dieter; Prosch, Helmut; Müller-Mang, Christina; Schmidt-Erfurth, Ursula; Langs, Georg

2014-01-01

457

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

NASA Technical Reports Server (NTRS)

We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 micrometers, 1450 times the mean-free path.

Sadlier, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.

2009-01-01

458

Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors  

NASA Technical Reports Server (NTRS)

We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T(sub c) of the TES is current-dependent and at fixed current scales as 1/L(sup 2). We also have found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 micrometers, 1450 times the mean-free path.

Sadleir, John E.; Smith, Stephen J.; Bandler, Simon R.; Chervenak, James A.; Clem, John R.

2010-01-01

459

Deisgn of the APS transverse and longitudinal damping system  

SciTech Connect

The three stripline damper system designed to reduce instability growth in the Advanced Photon Source Storage ring is described. The main sources of instability growth are higher-order modes of the accelerating cavities and the resistive wall impedance of the small insertion devices beam tubes. The transverse damping system will be dominated by the resistive wall modes and the longitudinal damper will reduce the higher-order modes from the accelerating cavities. Three stripline units will be used: One as a pickup, one as a transverse damper, and one as a longitudinal damper. They will each contain four strips located symmetrically about the vertical center plane at the top of an elliptical beam tube and two located at the bottom. (AIP) {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

Sellyey, W.; Barr, D.; Kahana, E.; Votaw, A. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

1995-05-05

460

Baseline patient characteristics and mortality associated with longitudinal intervention compliance  

PubMed Central

SUMMARY Lin et al. (http://www.biostatsresearch.com/upennbiostat/papers/, 2006) proposed a nested Markov compliance class model in the Imbens and Rubin compliance class model framework to account for time-varying subject noncompliance in longitudinal randomized intervention studies. We use superclasses, or latent compliance class principal strata, to describe longitudinal compliance patterns, and time-varying compliance classes are assumed to depend on the history of compliance. In this paper, we search for good subject-level baseline predictors of these superclasses and also examine the relationship between these superclasses and all-cause mortality. Since the superclasses are completely latent in all subjects, we utilize multiple imputation techniques to draw inferences. We apply this approach to a randomized intervention study for elderly primary care patients with depression. PMID:17477334

Lin, Julia Y.; Ten Have, Thomas R.; Bogner, Hillary R.; Elliott, Michael R.

2010-01-01

461

Composite slip table of dissimilar materials for damping longitudinal modes  

DOEpatents

A vibration slip table for use in a vibration testing apparatus. The table s comprised of at least three composite layers of material; a first metal layer, a second damping layer, and a third layer having a high acoustic velocity relative to the first layer. The different acoustic velocities between the first and third layers cause relative shear displacements between the layers with the second layer damping the displacements between the first and third layers to reduce the table longitudinal vibration modes.

Gregory, Danny L. (Albuquerque, NM); Priddy, Tommy G. (Albuquerque, NM); Smallwood, David O. (Albuquerque, NM); Woodall, Tommy D. (Albuquerque, NM)

1991-01-01

462

Measurement of longitudinal relaxation times for spin-decoupled protons.  

NASA Technical Reports Server (NTRS)

Description of an experimental method for the determination of the longitudinal relaxation time for spin-decoupled protons by a modified version of the saturation recovery technique reported by Van Geet and Hume (1965). The described method should facilitate relaxation studies of chemically shifted protons (or fluorines) and can be applied to more complicated spin systems with the aid of triple resonance and noise-decoupling techniques.

Gerace, M. J.; Kuhlmann, K. F.

1972-01-01

463

Minimizing subject loss in a longitudinal study of deviant behavior  

Microsoft Academic Search

A number of techniques are described to prevent attrition of four different categories of subjects in a longitudinal study of deviant behavior.Difficult to schedule subjects required persistence, empathy and flexibility to ensure their continued participation.Reluctant subjects were persuaded to participate by taking special care to build rapport with that family.Subjects who initially refused were “turned around” by assuming that a

Judith L. Navratil; Stephanie M. Green; Rolf Loeber; Benjamin B. Lahey

1994-01-01

464

Formation of longitudinal, midface cracks in continuously-cast slabs  

Microsoft Academic Search

Based on a series of related investigations, a mechanism for the formation of longitudinal, midface cracks in strand-cast\\u000a slabs has been elucidated. Metallographic studies, X-ray analyses, and high-temperature tensile testing of as-cast slab samples,\\u000a together with computer predictions of heat flow, have been combined to show that the cracks open first close to the solidification\\u000a front where the ductility is

J. K. Brimacombe; F. Weinberg; E. B. Hawbolt

1979-01-01

465

Formation of longitudinal, midface cracks in continuously-cast slabs  

Microsoft Academic Search

Based on a series of related investigations, a mechanism for the formation of longitudinal, midface cracks in strand-cast slabs has been elucidated. Metallographic studies, X-ray analyses, and high-temperature tensile testing of as-cast slab samples, together with computer predictions of heat flow, have been combined to show that the cracks open first close to the solidification front where the ductility is

J. K. Brimacombe; F. Weinberg; E. B. Hawbolt

1979-01-01

466

Longitudinal and transverse feedback kickers for the ALS  

Microsoft Academic Search

We describe the development of electromagnetic kickers for coupled-bunch feedback systems at the ALS. Transverse kickers are of a stripline design with one kicker per plane, operating in the baseband, 10 kHz to 250 MHz. Longitudinal kickers are of a coaxial design with electrodes paired in series operating over the band 1.00 to 1.25 GHz. Operating-band measurements and parasitic impedance

J. N. Corlett; J. Johnson; Glen R Lambertson; F. Voelker

1994-01-01

467

Investigation of longitudinal control system for a small hydrofoil boat  

NASA Technical Reports Server (NTRS)

An analysis of a hydromechanical system for longitudinal control of a small hydrofoil boat is presented. The system incorporates height and acceleration sensors operating flaps on the foils through a mechanical linkage. Effects of some of the system parameters on the stability and response to waves are shown. The results indicate that the system is capable of providing adequate stability, but the response to stern waves at low frequencies is larger than desired.

Phillips, W. H.; Shaughnessy, J. D.

1976-01-01

468

Longitudinal profile monitors using Coherent Smith-Purcell radiation  

NASA Astrophysics Data System (ADS)

Coherent Smith-Purcell radiation has the potential of providing information on the longitudinal profile of an electron bunch. The E-203 experiment at the FACET User Facility measures bunch profiles from the SLAC linac in the hundreds of femtoseconds range and the SPESO collaboration at Synchrotron SOLEIL is planning to make an accurate 2D map of the Coherent Smith-Purcell Radiation emission.

Andrews, H. L.; Bakkali Taheri, F.; Barros, J.; Bartolini, R.; Cassinari, L.; Clarke, C.; Le Corre, S.; Delerue, N.; Doucas, G.; Fuster-Martinez, N.; Konoplev, I.; Labat, M.; Perry, C.; Reichold, A.; Stevenson, S.; Vieille Grosjean, M.

2014-03-01

469

KmL: K-means for Clustering Longitudinal Data  

Microsoft Academic Search

The package KmL(1) is a generalization of the K-means algorithm for clus- tering Longitudinal data. Cohort studies are becoming essential tools in epidemiological research. In these studies, measurements are no longer restricted to a single variable but can be seen as trajectories. K-means is one of the statistical methods that can be used to determine homogeneous groups of patients trajectories.

Christophe Genolini; Bruno Falissard

470

A longitudinal study of cyberbullying: Examining riskand protective factors  

Microsoft Academic Search

The objective of the current study was to examine possible risk (school-bullying and victimization, exposure to media violence, callous-unemotional traits, impulsivity and narcissism) and protective (family, peer and school social support) factors that might be associated with cyberbullying and cyber-victimization by employing a longitudinal, two-wave design. The sample consisted of 1,416 (50.1% girls) adolescents living in Cyprus. The findings suggested

Kostas A. Fanti; Andreas G. Demetriou; Veronica V. Hawa

2012-01-01

471

Nonlinear H_ Missile Longitudinal Autopilot Design with 8- D Method  

Microsoft Academic Search

In this paper, a new nonlinear control synthesis technique, 8-D method, is employed to design a missile longitudinal autopilot. The 8 - D technique yields suboptimal solutions to nonlinear optimal control problems in the sense that it provides approximate solution to the Hamilton-lacobi-Bellman (HIB) equation. Semi-global asymptotic stability can be achieved by manipulating the perturbation terms which are added to

Ming Xin; S. N. Balakrishnan

2003-01-01

472

A longitudinal study of adolescent mental health service use  

Microsoft Academic Search

This study examines longitudinal mental health service use patterns of a school-based sample of adolescents. Based on the Center for Epidemiologic Studies Depression Scale scores, a stratified sample of middle-school students was interviewed using the Schedule for Affective Disorders and Schizophrenia for School-Aged Children: cycle one (n = 579; mean age 12.83) and cycle two (n = 490; mean age

Steven P. Cuffe; Jennifer L. Waller; Cheryl L. Addy; Robert E. McKeown; Kirby L. Jackson; Jamaluddin Moloo; Carol Z. Garrison

2001-01-01

473

A longitudinal study of domestic water conservation behavior  

Microsoft Academic Search

A 1988 study of a school-linked sample in a metropolitan and a regional urban area established baseline data for knowledge, attitudes, intentions, and behavior with regard to water management and conservation (Murphy, Watson, & Moore, 1991). This paper reports on a 1991 follow-up, utilising both longitudinal and cross-sectional samples of students, teachers and parents, which aimed at identifying changes within

Susan Moore; Margot Murphy; Ray Watson

1994-01-01

474

Mental disorders in ecstasy users: a prospective-longitudinal investigation  

Microsoft Academic Search

Objectives: To investigate the relationship between ecstasy use and mental disorders in a representative sample of adolescents and young adults. Method: Data for this investigation were drawn from the Early Developmental Stages of Psychopathology (EDSP) study, an epidemiological–longitudinal study in which 14–24 year-olds were examined prospectively over a period of about 4 years. Results are based on N=2462 participants who

Roselind Lieb; Christian G. Schuetz; Hildegard Pfister; Kirsten von Sydow; Hans-Ulrich Wittchen

2002-01-01

475

15-year longitudinal study of blood pressure and dementia  

Microsoft Academic Search

SummaryBackground Vascular causes of dementia may be more common than supposed. Vascular factors may also have a role in late-onset Alzheimer's disease, but the role of hypertension in the development of dementia is unclear.Methods As part of the Longitudinal Population Study of 70-year-olds in Göteborg, Sweden, we analysed the relation between blood pressure and the development of dementia in the

I Skoog; L Nilsson; G Persson; B Lernfelt; S Landahl; B Palmertz; L-A Andreasson; A Odén; A Svanborg

1996-01-01

476

Generalized longitudinal susceptibility for magnetic monopoles in spin ice  

PubMed Central

The generalized longitudinal susceptibility ?(q,?) affords a sensitive measure of the spatial and temporal correlations of magnetic monopoles in spin ice. Starting with the monopole model, a mean field expression for ?(q,?) is derived as well as expressions for the mean square longitudinal field and induction at a point. Monopole motion is shown to be strongly correlated, and both spatial and temporal correlations are controlled by the dimensionless monopole density x which defines the ratio of the magnetization relaxation rate and the monopole hop rate. Thermal effects and spin-lattice relaxation are also considered. The derived equations are applicable in the temperature range where the Wien effect for magnetic monopoles is negligible. They are discussed in the context of existing theories of spin ice and the following experimental techniques: DC and AC magnetization, neutron scattering, neutron spin echo and longitudinal and transverse field ?SR. The monopole theory is found to unify diverse experimental results, but several discrepancies between theory and experiment are identified. One of these, concerning the neutron scattering line shape, is explained by means of a phenomenological modification to the theory. PMID:23166378

Bramwell, Steven T.

2012-01-01

477

The Bielefeld Longitudinal Study of Adult Twins (BiLSAT).  

PubMed

The Bielefeld Longitudinal Study of Adult Twins (BiLSAT) is a German longitudinal study of monozygotic and dizygotic twins reared together, including more than 1,100 twin pairs aged between 14 and 80 who participated in the first wave. Data were collected at five waves of assessment between 1993 and 2009. Initially, the study focused on genetic and environmental influences on the structure and the development in adult temperament and personality. Today, the study includes a broad range of individual variables, such as personality disorders, major life goals, interests, attitudes, values, life and work satisfaction, and major life events. A special feature of this genetically informative study lies in the multiple-rater approach (i.e., self-reports and peer reports). Longitudinal multiple-rater analyses allow researchers to go beyond the basic nature-nurture decomposition of variance in self-reports examining genetic and environmental influences on stability and change in more accurately measured individual attributes. In the current article, we briefly describe the design and contents of BiLSAT as well as some recent major findings and future plans. PMID:23046571

Kandler, Christian; Riemann, Rainer; Spinath, Frank M; Bleidorn, Wiebke; Thiel, Wolfgang; Angleitner, Alois

2013-02-01

478

Longitudinal variability of ethane ice on the surface of Pluto  

E-print Network

We present the results of an investigation using near-infrared spectra of Pluto taken on 72 separate nights using SpeX/IRTF. These data were obtained between 2001 and 2013 at various sub-observer longitudes. The aim of this work was to confirm the presence of ethane ice and to determine any longitudinal trends on the surface of Pluto. We computed models of the continuum near the 2.405 {\\mu}m ethane band using Hapke theory and calculated an equivalent width of the ethane absorption feature for six evenly-spaced longitude bins and a grand average spectrum. Ethane on Pluto was confirmed at the 7.5-{\\sigma} level from the grand average spectrum. Additionally, ethane was found to vary longitudinally with the highest abundance present in the N2-rich region and the lowest abundance found in the visibly dark tholin-rich region. We argue for ethane production in the atmosphere and present a theory of volatile transport to explain the observed longitudinal trend.

Holler, B J; Grundy, W M; Olkin, C B; Cook, J C

2014-01-01

479

Multiscale Adaptive Generalized Estimating Equations for Longitudinal Neuroimaging Data 1  

PubMed Central

Many large-scale longitudinal imaging studies have been or are being widely conducted to better understand the progress of neuropsychiatric and neurodegenerative disorders and normal brain development. The goal of this article is to develop a multiscale adaptive generalized estimation equation (MAGEE) method for spatial and adaptive analysis of neuroimaging data from longitudinal studies. MAGEE is applicable to making statistical inference on regression coefficients in both balanced and unbalanced longitudinal designs and even twin and familial studies, whereas standard software platforms have several major limitations in handling these complex studies. Specifically, conventional voxel-based analyses in these software platforms involve Gaussian smoothing imaging data and then independently fitting a statistical model at each voxel. However, the conventional smoothing methods suffer from the lack of spatial adaptivity to the shape and spatial extent of region of interest and the arbitrary choice of smoothing extent, while independently fitting statistical models across voxels does not account for the spatial properties of imaging observations and noise distribution. To address such drawbacks, we adapt a powerful propagation–separation (PS) procedure to sequentially incorporate the neighboring information of each voxel and develop a new novel strategy to solely update a set of parameters of interest, while fixing other nuisance parameters at their initial estimators. Simulation studies and real data analysis show that MAGEE significantly outperforms voxel-based analysis. PMID:23357075

Li, Yimei; Gilmore, John H.; Shen, Dinggang; Styner, Martin; Lin, Weili; Zhu, Hongtu

2013-01-01

480

Ionospheric longitudinal variations at midlatitudes: symmetry and variability  

NASA Astrophysics Data System (ADS)

A characteristic ionospheric longitudinal variation at midlatitudes across the zero magnetic declination has been identified recently. Electron densities on east and west sides of the zero declination show systematical differences that vary with local time, season and solar cycle. This was first found for the continental US, and then confirmed for several other sectors. A declination-zonal wind mechanism was proposed to account for this class of variations. This presentation will attempt to address the generality of the tangible east-west difference in space and time. By using a 12-year long ground-based GPS TEC dataset for North America and performing empirical orthorgenal function (EOF) decomposition for spatial and temporal variations, we are able to view a striking symmetric longitudinal variation of the ionosphere, with respect to magnetic declination. This symmetry in TEC is an overwelming feature of the second mode EOF basis, and matches perfectly well with that in the vertical drift driven by thermospheric zonal winds under the influence of longitudinally varying declination. This study highlights the substantial control of the geomagnetic field on mesoscale ionospheric structures at a broad sense of midlatitudes.

Zhang, S.; Chen, Z.; Coster, A. J.; Erickson, P. J.

2013-12-01

481

Analysis of Longitudinal Data with Semiparametric Estimation of Covariance Function  

PubMed Central

Improving efficiency for regression coefficients and predicting trajectories of individuals are two important aspects in analysis of longitudinal data. Both involve estimation of the covariance function. Yet, challenges arise in estimating the covariance function of longitudinal data collected at irregular time points. A class of semiparametric models for the covariance function is proposed by imposing a parametric correlation structure while allowing a nonparametric variance function. A kernel estimator is developed for the estimation of the nonparametric variance function. Two methods, a quasi-likelihood approach and a minimum generalized variance method, are proposed for estimating parameters in the correlation structure. We introduce a semiparametric varying coefficient partially linear model for longitudinal data and propose an estimation procedure for model coefficients by using a profile weighted least squares approach. Sampling properties of the proposed estimation procedures are studied and asymptotic normality of the resulting estimators is established. Finite sample performance of the proposed procedures is assessed by Monte Carlo simulation studies. The proposed methodology is illustrated by an analysis of a real data example. PMID:19707537

Fan, Jianqing; Huang, Tao; Li, Runze

2009-01-01

482

Modeling Time Varying Effects with Generalized and Unsynchronized Longitudinal Data  

PubMed Central

Summary We propose novel estimation approaches for generalized varying coefficient models that are tailored for unsynchronized, irregular and infrequent longitudinal designs/data. Unsynchronized longitudinal data refers to the time-dependent response and covariate measurements for each individual measured at distinct time points. The proposed methods are motivated by data from the Comprehensive Dialysis Study (CDS). We model the potential age-varying association between infection-related hospitalization status and the inflammatory marker, C-reactive protein (CRP), within the first two years from initiation of dialysis. Traditional longitudinal modeling cannot directly be applied to unsynchronized data and no method exists to estimate time- or age-varying effects for generalized outcomes (e.g., binary or count data) to date. In addition, through the analysis of the CDS data and simulation studies, we show that preprocessing steps, such as binning, needed to synchronize data to apply traditional modeling can lead to significant loss of information in this context. In contrast, the proposed approaches discard no observation; they exploit the fact that although there is little information in a single subject trajectory due to irregularity and infrequency, the moments of the underlying processes can be accurately and efficiently recovered by pooling information from all subjects using functional data analysis. Subject-specific mean response trajectory predictions are derived and finite sample properties of the estimators are studied. PMID:23335196

?entürk, Damla; Dalrymple, Lorien S.; Mohammed, Sandra M.; Kaysen, George A.; Nguyen, Danh V.

2013-01-01

483

Joint modeling of event time and nonignorable missing longitudinal data.  

PubMed

Survival studies usually collect on each participant, both duration until some terminal event and repeated measures of a time-dependent covariate. Such a covariate is referred to as an internal time-dependent covariate. Usually, some subjects drop out of the study before occurrence of the terminal event of interest. One may then wish to evaluate the relationship between time to dropout and the internal covariate. The Cox model is a standard framework for that purpose. Here, we address this problem in situations where the value of the covariate at dropout is unobserved. We suggest a joint model which combines a first-order Markov model for the longitudinally measured covariate with a time-dependent Cox model for the dropout process. We consider maximum likelihood estimation in this model and show how estimation can be carried out via the EM-algorithm. We state that the suggested joint model may have applications in the context of longitudinal data with nonignorable dropout. Indeed, it can be viewed as generalizing Diggle and Kenward's model (1994) to situations where dropout may occur at any point in time and may be censored. Hence we apply both models and compare their results on a data set concerning longitudinal measurements among patients in a cancer clinical trial. PMID:12048867

Dupuy, Jean-François; Mesbah, Mounir

2002-06-01

484

Longitudinal in vivo MR imaging of live earthworms.  

PubMed

Earthworm (Oligochaeta, Lumbricidae) species are used widely in eco-toxicological tests especially with contaminated soils. These long-term tests are reliable, but a high sample size is needed. Magnetic resonance imaging (MRI) can produce fast, robust, sensitive, and longitudinal morphological results using a small sample size. Performing longitudinal in vivo examinations of earthworms using MRI requires the need for anesthetics to completely avoid earthworm's moving. Our goal was to develop a simple and non-invasive method to anesthetize earthworms for in vivo longitudinal imaging studies. We investigated a number of different anesthesia methods and found that propan-2-ol and its vapor was optimal. We used a commercial sequential nanoScan® PET/MRI system (Mediso Ltd, Hungary, Budapest) to explore feasibility of MR imaging in immobilized earthworms. It was possible to visualize via micro MRI the brain, gastrointestinal tract, seminal vesicles, calciferous gland (Morren gland), and main blood vessels of the circulatory system. Our findings show the possibilities to examine changes in morphology using MRI of certain organs using a reversible, long-term immobilization method. PMID:25059556

Budán, Ferenc; Kovács, Noémi; Engelmann, Péter; Horváth, Ildikó; Veres, Dániel S; Németh, Péter; Szigeti, Krisztián; Máthé, Domokos

2014-11-01

485

Generation of longitudinally polarized optical chain by 4? focusing system  

NASA Astrophysics Data System (ADS)

A longitudinally polarized optical chain is generated in a proposed 4? focusing system. The radially polarized Bessel-Gaussian incident beam is modulated by a complex amplitude filter. Their focusing performance is investigated using the Debye integral. Longitudinally polarized focusing spots with uniform intensity, high axial resolution and small spot volume are achieved in the proposed scheme. The number of the focusing spots in the optical chain is controllable by adjusting the complex amplitude filter. As an example, a longitudinally polarized optical chain with seven uniform intensity focusing spots is obtained. The volume of each focusing spot is reduced by about seven times and the axial resolution is only one-fourth of that in a single lens system with the same parameters. The influence of optical axes mismatching and foci shifting on the focusing performance is also investigated. The focusing system with the complex amplitude filter permits a large foci shifting because of the elongated depth of focus. It is expected that the research results can be used in the field of confocal microscopy, optical trapping and manipulating.

Lin, Jie; Chen, Ran; Jin, Peng; Cada, Michael; Ma, Yuan

2015-04-01

486

Longitudinal and transverse response functions for quasielastic electron scattering  

SciTech Connect

We consider the longitudinal and transverse response functions for quasielastic electron scattering from /sup 56/Fe. In a previous work we showed that the longitudinal response is overestimated by about forty percent in the impulse approximation. We argued that short-range correlations, among other effects, could shift transition strength to higher energies. To account for these features we multiplied the cross sections by a factor Z/sup 2/, where Z is a measure of the strength of the quasiparticle pole. The model we proposed then led to a significant underestimate of the transverse response. In this work we concentrate on the analysis of the transverse response and consider the electromagnetic properties of an interacting system of nucleons and deltas. Specific assumptions concerning the transition amplitudes NN/sup -1/..-->..NN/sup -1/ and NN/sup -1/..--> delta..N/sup -1/ allow for a simultaneous fit to both the longitudinal and transverse response functions. In our model the amplitude NN/sup -1/..--> delta..N/sup -1/ is governed by rho exchange with no additional correlation corrections. The model further requires that the NN/sup -1/..-->..NN/sup -1/ amplitude be small for the momentum transfers considered here: 210 MeV/c< or =Vertical BarqVertical Bar< or =410 MeV/c. Some theoretical support is offered for these small values of the latter amplitude.

Celenza, L.S.; Pong, W.S.; Shakin, C.M.

1983-06-01

487

Signal Detection and Monitoring Based on Longitudinal Healthcare Data  

PubMed Central

Post-marketing detection and surveillance of potential safety hazards are crucial tasks in pharmacovigilance. To uncover such safety risks, a wide set of techniques has been developed for spontaneous reporting data and, more recently, for longitudinal data. This paper gives a broad overview of the signal detection process and introduces some types of data sources typically used. The most commonly applied signal detection algorithms are presented, covering simple frequentistic methods like the proportional reporting rate or the reporting odds ratio, more advanced Bayesian techniques for spontaneous and longitudinal data, e.g., the Bayesian Confidence Propagation Neural Network or the Multi-item Gamma-Poisson Shrinker and methods developed for longitudinal data only, like the IC temporal pattern detection. Additionally, the problem of adjustment for underlying confounding is discussed and the most common strategies to automatically identify false-positive signals are addressed. A drug monitoring technique based on Wald’s sequential probability ratio test is presented. For each method, a real-life application is given, and a wide set of literature for further reading is referenced. PMID:24300373

Suling, Marc; Pigeot, Iris

2012-01-01

488

Flexible parametric joint modelling of longitudinal and survival data.  

PubMed

The joint modelling of longitudinal and survival data is a highly active area of biostatistical research. The submodel for the longitudinal biomarker usually takes the form of a linear mixed effects model. We describe a flexible parametric approach for the survival submodel that models the log baseline cumulative hazard using restricted cubic splines. This approach overcomes limitations of standard parametric choices for the survival submodel, which can lack the flexibility to effectively capture the shape of the underlying hazard function. Numerical integration techniques, such as Gauss-Hermite quadrature, are usually required to evaluate both the cumulative hazard and the overall joint likelihood; however, by using a flexible parametric model, the cumulative hazard has an analytically tractable form, providing considerable computational benefits. We conduct an extensive simulation study to assess the proposed model, comparing it with a B-spline formulation, illustrating insensitivity of parameter estimates to the baseline cumulative hazard function specification. Furthermore, we compare non-adaptive and fully adaptive quadrature, showing the superiority of adaptive quadrature in evaluating the joint likelihood. We also describe a useful technique to simulate survival times from complex baseline hazard functions and illustrate the methods using an example data set investigating the association between longitudinal prothrombin index and survival of patients with liver cirrhosis, showing greater flexibility and improved stability with fewer parameters under the proposed model compared with the B-spline approach. We provide user-friendly Stata software. PMID:23037571

Crowther, Michael J; Abrams, Keith R; Lambert, Paul C

2012-12-30

489

TRANSVERSE OSCILLATIONS OF A LONGITUDINALLY STRATIFIED CORONAL LOOP SYSTEM  

SciTech Connect

Collective transverse coronal loop oscillations seem to be detected in observational studies. In this regard, Luna et al. modeled the collective kink-like normal modes of several cylindrical loop systems using the T-matrix theory. This paper investigates the effects of longitudinal density stratification along the loop axis on the collective kink-like modes of the system of coronal loops. The coronal loop system is modeled as cylinders of parallel flux tubes, with two ends of each loop at the dense photosphere. The flux tubes are considered as uniform magnetic fields, with stratified density along the loop axis which changes discontinuously at the lateral surface of each cylinder. The MHD equations are reduced to solve a set of two coupled dispersion relations for frequencies and wavenumbers, in the presence of a stratification parameter. The fundamental and first overtone frequencies and longitudinal wavenumbers are computed. The previous results are verified for an unstratified coronal loop system. Finally, we conclude that an increased longitudinal density stratification parameter will result in an increase of the frequencies. The frequency ratios, first overtones to fundamentals, are very sensitive functions of the density scale height parameter. Therefore, stratification should be included in dynamics of coronal loop systems. For unstratified coronal loop systems, these ratios are the same as monoloop ones.

Fathalian, N. [Institute for Advanced Studies in Basic Sciences, P.O. Box 45195-1159, Zanjan (Iran, Islamic Republic of); Safari, H., E-mail: fathalian@iasbs.ac.i, E-mail: safari@znu.ac.i [Department of Physics, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)

2010-11-20

490

Characteristic ionospheric longitudinal variations at midlatitudes over North America  

NASA Astrophysics Data System (ADS)

The midlatitude ionosphere is known to feature substantial differences between the Asian and American sectors caused by the offset between the magnetic and geographic coordinate systems. This paper deals with a new type of ionospheric longitudinal variation at midlatitudes that is associated with magnetic declination and the thermospheric zonal wind. Over the continental US, the total electron content (TEC) exhibits a prominent east-west coast difference, which varies with local time, season and solar activity. Above the eastern US, there appears a similar east-west difference in the F-region electron density as indicated in the long-term super-wide coverage experiments by the Millstone Hill incoherent scatter radar (ISR). We suggest that this type of longitudinal variation at midlatitude is caused by a combined effect of the magnetic declination difference and varying thermospheric zonal winds. The magnetic declination reverses its direction near the central US and is over 15 degress in the eastern US. Meanwhile, the long-term Fabry-Perot interferometer (FPI) zonal wind observations at Millstone Hill show very high correlation with the east-west electron density difference in the F-region. This paper reports results from the TEC, ISR and FPI observations that demonstrate the characteristic longitudinal variation at midlatitudes over the US and its causative mechanism.

Zhang, S.; Foster, J. C.; Coster, A. J.; Erickson, P. J.

2012-12-01

491

The longitudinal gracilis myocutaneous flap: broadening options in breast reconstruction.  

PubMed

Many patients who present for autogenous breast reconstruction are not suitable candidates for abdominal wall flaps, either because of previous abdominal surgery (most commonly transverse rectus abdominis myocutaneous flap for prior breast reconstruction) or because of the lack of enough adipose tissue. Another donor site option is the medial thigh that has more recently been recognized as a source of tissue for breast reconstruction. Prior reports have described the harvest of a gracilis myocutaneous flap through a transverse incision. From August 2004 to April 2007, 12 patients underwent autogenous breast reconstruction of 15 breasts with the longitudinal gracilis myocutaneous microvascular flap. The patients' ages ranged from 41 to 60 years (average, 48 years). In all patients the longitudinal gracilis flap was chosen because of a desire for autogenous reconstruction and a lack of available abdominal wall tissue. Mean follow-up of the 12 patients was 16.8 months (range, 5-36 months). There was no microvascular thrombosis or free-flap failure in this series. Donor sites were well tolerated by all patients. Three patients underwent suction-assisted lipectomy of 5 donor site areas to improve contour and/or symmetry. The longitudinal gracilis myocutaneous flap is a useful alternative for breast reconstruction in properly selected patients. PMID:18948778

Kind, Gabriel M; Foster, Robert D

2008-11-01

492

Piezoelectric linear motor concepts based on coupling of longitudinal vibrations.  

PubMed

Classically, rotary motors with gears and spindle mechanisms are used to achieve translatory motion. In means of miniaturization and weight reduction piezoelectric linear motors are of interest. Several ultrasonic linear motors found in literature base on the use of two different vibration modes. Most often flexural and longitudinal modes are combined to achieve an elliptic micro-motion of surface points. This micro-motion is converted to direct linear (or translatory) motion of a driven slider. To gain high amplitudes of the micro-motion and thus having a powerful motor, the ultrasonic vibrator should be driven near the eigenfrequency of its modes. Additionally, low mechanical and electrical losses lead to increased efficiency and large amplitude magnification in resonance. This demands a geometrical design that fits the eigenfrequencies of the two different modes. A frequency-deviation of only a few percent leads to non-acceptable disturbance of the elliptical motion. Thus, the mechanical design of the vibrators has to be done very carefully. Within this contribution we discuss different motor designs based on the coupling of two the same longitudinal vibrations within one structure to generate an elliptic motion of surface points. Different concepts based on piezoelectric plates and Langevin transducers are compared. Benefits and drawbacks against the combination of longitudinal and bending modes will be discussed. Numerical results of the stator vibration as well as motor characteristics are validated by measurements on different prototypes. PMID:16782160

Hemsel, T; Mracek, M; Twiefel, J; Vasiljev, P

2006-12-22

493

Myelomeningocoele and a dermoid sinus-like lesion in a French bulldog  

PubMed Central

A 2-year-old male French bulldog was presented for investigation of lumbosacral pain and hindlimb ataxia associated with urinary and fecal incontinence. Survey radiography, myelography, and computed tomography images were suggestive of a dermoid sinus with associated spina bifida. Surgical intervention led to a resolution of pain and neurological deficits. Histopathological analysis of the excised tissue was compatible with a myelomeningocoele of the 7th lumbar vertebra. PMID:24293672

Ployart, Stéphane; Doran, Ivan; Bomassi, Eric; Bille, Christophe; Libermann, Stéphane

2013-01-01

494

Antegrade continence enema (ACE): current practice  

Microsoft Academic Search

The purpose of this study was to assess current status of antegrade continence enema (ACE) procedure taking into account the\\u000a recent improvement in the technique and outcome. Reviewing our record of 48 patients with ACE procedure performed between\\u000a January 2002 and May 2007, we found that the underlying diagnoses were idiopathic constipation in 56%, anorectal malformation\\u000a in 31%, spina bifida

Chandrasen Kumar Sinha; Alka Grewal; Harry C. Ward

2008-01-01

495

Herbicide exposure and veterans with covered service in Korea. Final rule.  

PubMed

This document adopts as a final rule the Department of Veterans Affairs' (VA) proposal to amend VA adjudication, medical, and vocational rehabilitation and employment regulations to incorporate relevant provisions of the Veterans Benefits Act of 2003. Specifically, this document amends VA regulations regarding herbicide exposure of certain veterans who served in or near the Korean demilitarized zone and regulations regarding spina bifida in their children. It also amends VA's medical regulations by correcting the Health Administration Center's hand-delivery address. PMID:21275190

2011-01-25

496

Primary tethered cord syndrome: diagnosis and treatment of an insidious defect.  

PubMed

Failure to recognize the signs and symptoms of tethered cord syndrome in patients with spina bifida occulta can result in tragic consequences. Of patients with tethered spinal cord, 35% have bowel and/or bladder dysfunction. Scoliosis, foot or leg length discrepancies, pes cavus, and varus or valgus deformities also can occur. Early assessment and intervention by the neuroscience nurse who is familiar with these clinical signs can help prevent significant deformities and irreversible neurological deficits. PMID:10994534

Cartwright, C

2000-08-01

497

Knowledge and use of folic acid by women of childbearing age--United States, 1997.  

PubMed

Each year in the United States, approximately 4000 pregnancies are affected by spina bifida and anencephaly. Babies born with spina bifida usually survive, often with serious disability, but anencephaly is invariably fatal. The B vitamin folic acid can reduce the occurrence of spina bifida and anencephaly by at least 50% when consumed daily before conception and during early pregnancy. In 1992, the Public Health Service (PHS) recommended that all women of childbearing age who are capable of becoming pregnant consume 400 microg of folic acid daily. Folic acid can be obtained from multivitamins or certain other supplements and from some fortified breakfast cereals. It is found naturally in orange juice, green leafy vegetables, and beans; however, it is difficult to obtain the recommended 400 microg daily through diet alone. This report summarizes findings from a survey conducted during January and February 1997 that indicate modest increases since 1995 in knowledge about and consumption of folic acid among U.S. women aged 18-45 years and highlights the need for additional public health efforts to take full advantage of this prevention opportunity. PMID:9262072

1997-08-01

498

A Longitudinal Examination of Childhood Maltreatment and Adolescent Obesity: Results from the National Longitudinal Study of Adolescent Health (AddHealth) Study  

ERIC Educational Resources Information Center

Objectives: We sought to explore the association between childhood maltreatment (e.g., neglect, physical and sexual abuse) and longitudinal growth trajectories of body mass index (BMI) from adolescence to young adulthood. Methods: We used latent curve modeling to examine data from the National Longitudinal Study of Adolescent Health (N = 8,471),…

Shin, Sunny Hyucksun; Miller, Daniel P.

2012-01-01

499

Biases in Multicenter Longitudinal PET Standardized Uptake Value Measurements1  

PubMed Central

This study investigates measurement biases in longitudinal positron-emission tomography/computed tomography (PET/CT) studies that are due to instrumentation variability including human error. Improved estimation of variability between patient scans is of particular importance for assessing response to therapy and multicenter trials. We used National Institute of Standards and Technology-traceable calibration methodology for solid germanium-68/gallium-68 (68Ge/68Ga) sources used as surrogates for fluorine-18 (18F) in radionuclide activity calibrators. One cross-calibration kit was constructed for both dose calibrators and PET scanners using the same 9-month half-life batch of 68Ge/68Ga in epoxy. Repeat measurements occurred in a local network of PET imaging sites to assess standardized uptake value (SUV) errors over time for six dose calibrators from two major manufacturers and for six PET/CT scanners from three major manufacturers. Bias in activity measures by dose calibrators ranged from -50% to 9% and was relatively stable over time except at one site that modified settings between measurements. Bias in activity concentration measures by PET scanners ranged from -27% to 13% with a median of 174 days between the six repeat scans (range, 29 to 226 days). Corresponding errors in SUV measurements ranged from -20% to 47%. SUV biases were not stable over time with longitudinal differences for individual scanners ranging from -11% to 59%. Bias in SUV measurements varied over time and between scanner sites. These results suggest that attention should be paid to PET scanner calibration for longitudinal studies and use of dose calibrator and scanner cross-calibration kits could be helpful for quality assurance and control. PMID:24772207

Doot, Robert K; Pierce, Larry A; Byrd, Darrin; Elston, Brian; Allberg, Keith C; Kinahan, Paul E

2014-01-01

500

A predictive model of longitudinal, patient-specific colonoscopy results.  

PubMed

We suggest a model framework, in which an individual patient's risk for colonic neoplasia varies based on findings from his previous colonoscopies, to predict longitudinal colonoscopy results. The neoplasia natural history model describes progression through four neoplasia development states with patient age. Multiple natural history model parameter sets are assumed to act concurrently on the colon and parameter set prevalence combinations, whose a priori likelihoods are a function of patient sex, provide a basis set for patient-level predictions. The novelty in this approach is that after a colonoscopy, both the parameter set combination likelihoods and their model predictions can adjust in a Bayesian manner based on the results and conditions of the colonoscopy. The adjustment of model predictions operationalizes the clinical knowledge that multiple or advanced neoplasia at baseline colonoscopy is an independent predictor of multiple or advanced neoplasia at follow-up colonoscopy--and vice versa for negative colonoscopies--and the adjustment of parameter set combination likelihoods accounts for the possibility that patients may have different neoplasia development rates. A model that accurately captures serial colonoscopy results could potentially be used to design and evaluate post-colonoscopy treatment strategies based on the risk of individual patients. To support model identification, observational longitudinal colonoscopy results, procedure details, and patient characteristics were collected for 4084 patients. We found that at least two parameter sets specific to each sex with model adjustments was required to capture the longitudinal colonoscopy data and inclusion of multiple possible parameter set combinations, which account for random variations within the population, was necessary to accurately predict the second-time colonoscopy findings for patients with a history of advanced adenomas. Application of this model to predict CRC risks for patients adhering to guideline recommended follow-up colonoscopy intervals found that there are significant differences in risk with patient age, gender, and preparation quality and demonstrates the need for a more rigorous investigation into these recommendations. PMID:23968894

Sherer, Eric A; Ambedkar, Sanmit; Perng, Sally; Yih, Yuehwern; Imperiale, Thomas F

2013-12-01