bluuebunny/crossref_metadata_2025_split huggingface dataset:
Height Discordance in Monozygotic Females is not Attributable to Discordant Inactivation of X-linked Stature Determining Genes
Authors: Healey S.C. , Kirk K.M. , Hyland V.J. , Munns C.F. , Henders A.K. , Batch J.A. , Heath A.C. , Martin N.G. , Glass I.A. 
Published: May 2007

AbstractWe tested the hypothesis that X-linked genes determining stature which are subject to skewed or non-random X-inactivation can account for discordance in height in monozygotic female twins. Height discordant female monozygotic adult twins (20 pairs) were identified from the Australian Twin Registry, employing the selection criteria of proven monozygosity and a measured height discordance of at least 5 cm. Differential X-inactivation was examined in genomic DNA extracted from peripheral lymphocytes by estimating differential methylation of alleles at the polymorphic CAG triplet repeat of the Androgen receptor gene (XAR). There were 17/20 MZ pairs heterozygous at this locus and informative for analysis. Of these, 10/17 both had random X-inactivation, 5/17 showed identical X-inactivation patterns of non random inactivation and 2/17 (12%) showed discordant X-inactivation. There was no relationship between inactivation patterns and self-report chorionicity. We conclude that non-random X-inactivation does not appear to be a major contributor to intra-pair height discordance in female MZ twins.
Twins, Chorionicity and Zygosity
Authors: Derom Robert , Bryan Elizabeth , Derom Catherine , Keith Louis , Vlietinck Robert 
Published: May 2007

AbstractAccurate determination of zygosity and chorionicity is essential in all multiple maternities. The parents and the multiples themselves ask it. It is of medical importance and now considered as a prerequisite in several domains of twin research, especially when perinatal data are analysed. It helps the multiples and their parents and teachers to ascertain identity. The methods are briefly described and a plea is made to obstetricians and paediatricians to use them systematically at the time of birth.
Induction of Labour and Scheduled Cesarean Deliveries in Twin Pregnancies at the Port-Royal Maternity Hospital in Paris France
Authors: Papiernik Emile , Hessabi Madieh , Dubourdieu Corinne , Zeitlin Jennifer 
Published: May 2007

AbstractThe study is a critical analysis of the decisions to induce labour or schedule cesareans in the practice of a third level referral centre, with as outcome criterion the reduction of fetal death. 783 women pregnant with twins were included from 1.1.1993 to 31.12.1998, in three groups:originally booked, referred for care during pregnancy, or transferred from another institution. The results show that an important proportion of preterm deliveries result from a medical decision to induce labour or from a scheduled cesarean in the originally booked group with even higher proportions in groups of referred and transferred women. These results are discussed in relation to fetal death rates and causes. Deaths related to fetal growth restriction were not observed in women originally booked for care. The hospital bias has been discussed. The conclusion is that decisions to minimize fetal deaths in twin pregnancies increased preterm deliveries by medical decision.
The Role of Ultrasound in Multiple Pregnancy
Authors: Arabin Birgit , van Eyck Jim 
Published: May 2007

AbstractThe advances in reproductive technologies have changed the demographics of multifetal pregnancies. In the first trimester, ultrasound allows to diagnose the number of multiples, chorionicity and amnionicity, the presence or absence of nuchal translucency, early growth discordance, severe malformations and the origin of activities and contacts between multiples. In the second and third trimester, the opportunity to examine the cervix by transvaginal ultrasound should not be missed to detect the risk of premature delivery. Ultrasound is essential for the early grading and treatment of twin-to-twin transfusion syndrome (TTTS), the diagnosis of malformations and growth disturbances. Doppler velocimetry has proven to be able to reduce perinatal mortality in twin pregnancies. Finally, ultrasound is used for the detection of the position of multiples and the decision of the optimal route of delivery. This is of main importance in delayed interval delivery and expectant management of multifetal pregnancies and early cervical dilatation.
Use of Monozygotic Twins in Search for Breast Cancer Susceptibility Loci
Authors: Försti Asta , Jin Qianren , Sundqvist Lena , Söderberg Magnus , Hemminki Kari 
Published: May 2007

AbstractWe have used Swedish monozygotic twins concordant for breast cancer to study genetic changes associated with the development of breast cancer. Because loss of heterozygosity (LOH) at a specific genomic region may reflect the presence of a tumour suppressor gene, loss of the same allele in both of the twins concordant for breast cancer may pinpoint a tumour suppressor gene that confers a strong predisposition to breast cancer. DNA samples extracted from the matched tumour and normal tissues of nine twin pairs were analysed for allelic imbalance using a set of microsatellite markers on chromosomes 1, 13, 16 and 17, containing loci with known tumour suppressor genes. The two main regions, where more twin pairs than expected had lost the same allele, were located at 16qtel, including markers D16S393, D16S305 and D16S413, and at 17p13, distal to the p53 locus. Our results show that the monozygotic twin model can be used to suggest candidate regions of potential tumour suppressor genes, even with a limited number of twin pairs.
Ascertainment of a Mid-Western US Female Adolescent Twin Cohort for Alcohol Studies: Assessment of Sample Representativeness Using Birth Record Data
Authors: Heath Andrew C. , Howells William , Bucholz Kathleen K. , Glowinski Anne L. , Nelson Elliot C. , Madden Pamela A. F. 
Published: May 2007

AbstractFemale twin pairs were identified from birth records, and their families invited to participate in a prospective study of the determinants of alcohol problems in women. We investigated sampling biases arising because of failure to locate families, or non-cooperation of families. Out of 2644 families with a live-born pair (born between July 1975 and December 1986) who survived beyond infancy, contact was established and a brief screening interview completed with 90% (N = 2380). Fewer than 6% of located families declined to participate in the initial screening interview. Predictors of failure to locate a family or to obtain a screening interview were identified from information recorded in birth records, and from neighborhood characteristics identified from 1990 US Census block group data for the family residence when the twins were born. African-American families were under-represented in the final sample, but this effect was barely significant when other variables were controlled for. Under-represented were families where the mother was 19 or younger at the birth of the twins, where the mother herself was born out-of-state, or where information about biological father was not reported in the birth record. Non-participating families on average came from neighborhoods with a higher proportion of residents living in poverty, and with a higher proportion of African-American residents. Sampling biases were however small. The unusual cooperativeness in research of families with twins persists.
Estimating Two-Stage Models for Genetic Influences on Alcohol, Tobacco or Drug Use Initiation and Dependence Vulnerability in Twin and Family Data
Authors: Heath Andrew C. , Martin Nicholas G. , Lynskey Michael T. , Todorov Alexandre A. , Madden Pamela A. F. 
Published: May 2007

AbstractGenetic research on risk of alcohol, tobacco or drug dependence must make allowance for the partial overlap of risk-factors for initiation of use, and risk-factors for dependence or other outcomes in users. Except in the extreme cases where genetic and environmental risk-factors for initiation and dependence overlap completely or are uncorrelated, there is no consensus about how best to estimate the magnitude of genetic or environmental correlations between Initiation and Dependence in twin and family data. We explore by computer simulation the biases to estimates of genetic and environmental parameters caused by model misspecification when Initiation can only be defined as a binary variable. For plausible simulated parameter values, the two-stage genetic models that we consider yield estimates of genetic and environmental variances for Dependence that, although biased, are not very discrepant from the true values. However, estimates of genetic (or environmental) correlations between Initiation and Dependence may be seriously biased, and may differ markedly under different two-stage models. Such estimates may have little credibility unless external data favor selection of one particular model. These problems can be avoided if Initiation can be assessed as a multiple-category variable (e.g. never versus early-onset versus later onset user), with at least two categories measurable in users at risk for dependence. Under these conditions, under certain distributional assumptions, recovery of simulated genetic and environmental correlations becomes possible. Illustrative application of the model to Australian twin data on smoking confirmed substantial heritability of smoking persistence (42%) with minimal overlap with genetic influences on initiation.
Fundal Height as a Predictor of Early Preterm Triplet Delivery
Authors: Yokoyama Yoshie 
Published: May 2007

AbstractThe purpose of this study was to create graphs of fundal height parameters in triplet pregnancies compared with those in twin pregnancies, and to investigate whether larger fundal heights in triplet pregnancies would predispose them to earlier delivery (before 34 weeks). The subjects were 727 twin pregnant women and 133 triplet pregnant women, who delivered after 1984. Triplet pregnancies showed significantly higher fundal heights compared with twin pregnancies at each gestational age (weeks). In triplet pregnancies, a single fundal height measurement above the 90th percentile before 34 weeks yielded a sensitivity of 31.3% and specificity of 82.4% for delivery before 34 weeks, with a positive predictive value of 50.0% and a negative predictive value of 68.0%. After adjusting for each associated factor using logistic regression, the risk of preterm labour was not significantly associated with a single fundal height measurement above the 90th percentile recorded before 34 weeks.
Paternal Familial Twinning: Hypothesis and Genetic/Medical Implications
Authors: Golubovsky Michael 
Published: May 2007

AbstractThe phenomenon of paternally dependent familial twinning has been known in human and animal genetics since the 1920s, but still remains without any theoretical explanation and is indeed a neglected field of inquiry. Over the last two decades investigations in reproduction biology have discovered the significant role of multiple paternally dependent errors in fertilization including androgenic triploidy and moles. We suggest the hypothesis that the fathers of twins in the relevant families carry gene variants that increase the probability of dispermy, diplospermy and male pronucleus heterochrony as well as involvement of two male pronuclei in the fertilization of two female meiotic products. Any resulting twins would be an exceptional intermediate between MZ and DZ twins — and might properly be described as “sesquizygotic” (SZ). Paternal familial twinning may also go together with infertility due to triploidy, moles and chimerism. The hypothesis: (i) places the curiosities of paternally derived twinning within the framework of current knowledge of reproductive genetics and verifiable phenomena; (ii) predicts the existence of families in which twinning is associated with reproductive abnormalities; (iii) predicts an occurrence in relevant families of the third and intermediate category of SZ twins. Families with paternal twinning may thus provide the natural selective system for the search of unusual cases of primary chimeras, the frequency of which is still unknown.
Heritabilities of Apolipoprotein and Lipid Levels in Three Countries
Authors: Beekman Marian , Heijmans Bastiaan T. , Martin Nicholas G. , Pedersen Nancy L. , Whitfield John B. , DeFaire Ulf , van Baal G. Caroline M. , Snieder Harold , Vogler George P. , Slagboom P. Eline , Boomsma Dorret I. 
Published: May 2007

AbstractThis study investigated the influence of genes and environment on the variation of apolipoprotein and lipid levels, which are important intermediate phenotypes in the pathways toward cardiovascular disease. Heritability estimates are presented, including those for apolipoprotein E and AII levels which have rarely been reported before. We studied twin samples from the Netherlands (two cohorts;n= 160 pairs, aged 13–22 andn= 204 pairs, aged 34–62), Australia (n= 1362 pairs, aged 28–92) and Sweden (n= 302 pairs, aged 42–88). The variation of apolipoprotein and lipid levels depended largely on the influences of additive genetic factors in each twin sample. There was no significant evidence for the influence of common environment. No sex differences in heritability estimates for any phenotype in any of the samples were observed. Heritabilities ranged from 0.48–0.87, with most heritabilities exceeding 0.60. The heritability estimates in the Dutch samples were significantly higher than in the Australian sample. The heritabilities for the Swedish were intermediate to the Dutch and the Australian samples and not significantly different from the heritabilities in these other two samples. Although sample specific effects are present, we have shown that genes play a major role in determining the variance of apolipoprotein and lipid levels in four independent twin samples from three different countries.
The Validity and Heritability of Self-Report Osteoarthritis in an Australian Older Twin Sample
Authors: Kirk Katherine M. , Bellamy Nicholas , O'Gorman Louise E. , Kuhnert Petra M. , Klestov Alex , Muirden Ken , Tesar Paul , Walker Duncan , Martin Nicholas G. 
Published: May 2007

AbstractIn order to investigate the genetic and environmental antecedents of osteoarthritis (OA), self-report measures of joint pain, stiffness and swelling were obtained from a popula-tion-based sample of 1242 twin pairs over 50 years of age. In order to provide validation for these self-report measures, a subsample of 118 twin pairs were examined according to the American College of Rheumatology clinical and radiographic criteria for the classification of osteoarthritis. A variety of statistical methods were employed to identify the model derived from self-report variables which would provide optimal prediction of these standardised assessments, and structural equation modelling was used to determine the relative influences of genetic and environmental influences on the development of osteoarthritis. Significant genetic effects were found to contribute to osteoarthritis of the hands, hips and knees in women, with heritability estimates ranging from 30–46% depending on the site. In addition, the additive genetic effects contributing to osteoarthritis in various parts of the body were confirmed to be the same. Statistically significant familial aggregation of osteoarthritis in men was also observed, but it was not possible to determine whether this was due to genetic or shared environmental effects.
Norwegian Twin Registers and Norwegian Twin Studies — An Overview
Authors: Bergem A.L. Mina 
Published: May 2007

AbstractThe Norwegian Twin Registers include several sets of population-based sub-registers, and covers twin pairs born between 1895 and today. Except for the missing birth years 1960 to 1967, the register is almost complete. Most of the register contains information about both same-sexed and opposite-sexed twin pairs, except for twin pairs born between 1946 and 1960, where only same-sexed twins are registered. In a substantial part of the register, information about zygosity is obtained, mainly by a mailed questionnaire and in some cases supported by DNA testing. These are the birth years 1915 to 1960 and the birth years 1967 to 1979. Zygosity information is further obtained in the different twin studies derived from the twin register. In 1990 the whole register was made available in a computerized form. Several twin studies have been derived from the different parts of the register. In this article, studies from the two earliest parts of the register are reviewed and grouped by recruitment specifics. Finally, future plans for the register and twin studies are discussed.
Chronic Ventilator Need in the Community: A 2005 Pediatric Census of Massachusetts
Authors: Graham Robert J. , Fleegler Eric W. , Robinson Walter M. 
Published: May 2007

OBJECTIVES. The purpose of this study was to describe the population of children with chronic mechanical ventilation in Massachusetts and their patterns of medical care.PATIENTS AND METHODS. Investigators surveyed all of the Massachusetts home ventilator clinics, pediatric pulmonary services, hospital-based pediatric services for special health care needs, insurers, home care vendors, nursing agencies, the Massachusetts Department of Public Health, selected individual providers, and rehabilitation and long-term care facilities providing services to children with chronic respiratory support needs. Support was defined as daily use of noninvasive, negative-pressure, or invasive/transtracheal ventilators. Subsequent matching of demographic data, including date of birth, zip code, and gender supported maximal census yield without duplications. Geographic information systems were used to create distribution maps and estimate distances between children with chronic mechanical ventilator needs and key resources.RESULTS. A total of 197 children were identified as requiring chronic mechanical respiratory support in Massachusetts in 2005, which was a nearly threefold increase in this population in the 15-year interval since the last census. Congenital or perinatal-acquired neurologic or neuromuscular disorders constituted the majority of primary diagnoses (n = 107 [54%]). Chronic lung disease attributed to prematurity represented only 7% of the sample.CONCLUSIONS. Children receiving chronic mechanical respiratory support are a growing population. The shift in underlying diagnoses from pulmonary disease to neurogenic respiratory insufficiency has implications for hospital and community-based providers from all disciplines in extending services to the home setting. Barriers encountered when performing this study, however, reflect an overall lack of coordination among the many individuals and agencies involved in their care. Coordinated and centralized care efforts require a clear and managed flow of information; census reports such as this one are only the beginning. Direct needs assessments and quality-of-life surveys from families are needed to design and implement programmatic changes and advocacy efforts.
Inviting Reluctant Adolescent Readers Into the Literacy Club: Some Comprehension Strategies to Tutor Individuals or Small Groups of Reluctant Readers
Authors: Ambe Elizabeth BiFuh 
Published: May 2007

Developing students' ability to read is a critical educational goal, necessary in order that students can become successful members of society. Proficiency in reading increases opportunities for higher education and promotes positive social change.Unfortunately, many students struggle with comprehension, especially in the content areas. Some have special learning needs, but others are simply reluctant learners. Direct systematic instruction in comprehension strategies and the use of enjoyable texts can encourage nonreaders to become part of our reading culture. This article describes strategies that
Enhance motivation
Develop prior knowledge
Improve vocabulary acquisition
Foster comprehension of both expository and narrative texts that students are likely to find in the content areas
This article is also the source for a Class Acts podcast. Download “Supporting struggling adolescent readers” from
www.reading.orgresourcespodcastsindex.html
Extracurricular Reading Habits of College Students in Taiwan: Findings From Two National Surveys
Authors: Chen Su‐Yen 
Published: May 2007

The Chinese people have great regard for those who read widely, yet little is known of the extracurricular reading behaviors of Chinese students. This study drew on data from two national surveys to investigate the amount of time Taiwanese college students spend on extracurricular reading. Findings are interpreted in relation to prior research on the reading habits of college students internationally. The study found that
Female students on average did not spend more time on extracurricular reading than males
Students from public institutions, who generally have higher academic competence, did not spend more time reading than students from private institutions
Education majors spent the least time on extracurricular reading
Newspapers, magazines, and bestsellers were the most popular reading materials, but manga (graphic novels) had medium popularity
Crosscultural differences might have an impact on the amount of time spent reading and on reading interests
Preservice Teacher Understandings of Adolescent Literacy Development: Naive Wonder to Dawning Realization to Intellectual Rigor
Authors: Freedman Lauren , Carver Cynthia 
Published: May 2007

How do secondary teacher candidates learn about their responsibility for the ongoing literacy development of their students? How do they gain the understandings and knowledge of instructional practices necessary to meet this responsibility within their content teaching?The authors document three stages of development their students progress through in the two integrated preservice courses they teach. In the first stage of “naive wonder,” the students exhibit enthusiasm for adolescent literacy development but provide only superficial, simplistic, and clichéd responses. At the stage of “dawning realization,” students begin to recognize the challenges involved and shift their focus from themselves as teachers to their students as learners. By the end of the two integrated courses, the students were in the third stage and approaching their responsibility for literacy development with intellectual rigor.
“I Was Bitten by a Scorpion”: Reading in and out of School in a Refugee's Life
Authors: Sarroub Loukia K. , Pernicek Todd , Sweeney Tracy 
Published: May 2007

This study examined the progress of Hayder, a high school student, in becoming a reader within an English language learner (ELL) reading program. The authors delve into the relationships between this young man's masculinity as a Yezidi Kurdish refugee, the reading instruction he received, his attempts to stay in school, and his successful literacy practices at home and in his workplace.There is a relatively small body of published literature on youth cultures and literacy in secondary schools, especially as it relates to ELL students who take part in innovative reading programs based on elementary reading research and curricula. Findings indicate that the reading instruction the teachers implement works for students such as Hayder when certain support structures are in place and when teachers are aware of the multiple literacies with which students engage outside of school.
“I Learned That There's a State Called Victoria and He Has Six Blue‐Tongued Lizards!”
Authors: Charron Nancy Necora 
Published: May 2007

In the study described in this article, fourth‐grade teachers and students of different abilities and language backgrounds were interviewed before, during, and after participating in an Internet pen pal program. Results reveal that the program's authentic tasks and texts facilitated communication and enabled students to learn about a different culture. Enthusiasm generated by the program was evidenced in student writing.This program motivated students to write. It facilitated problem solving and supported critical thinking in written‐language acquisition.