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Singletons

Distribution by Scientific Domains

Medical Sciences	60%
Life Sciences	24%
Psychology	3%
Humanities and Social Sciences	3%
Chemistry	2%
3 Other Domains	8%

Distribution within Medical Sciences

Obstetrics & Gynecology	48%
Pediatrics	8%
Women's Health Nursing	6%
Neurology	3%
9 Other Subdomains	35%

Terms modified by Singletons

Selected Abstracts

GROWING UP AMISH: THE TEENAGE YEARS. (The Young Center Books in Anabaptist and Pietistic Studies.) By Richard A. Stevick THE SPIRIT OF GENERATION Y: YOUNG PEOPLE'S SPIRITUALITY IN A CHANGING AUSTRALIA By MichaelMason, Andrew Singleton, and Ruth Webber TEENAGE WITCHES: MAGICAL YOUTH AND THE SEARCH FOR SELF By Helen A. Berger and Douglas Ezzy

JOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 3 2008
TIM CLYDESDALE
No abstract is available for this article. [source]

Neonatal C-reactive protein value in prediction of Outcome of Preterm Premature Rupture of Membranes: Comparison of Singleton and Twin Pregnancies

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2009
Simin Taghavi
Abstract Aim:, The clinical importance of preterm premature rupture of the membranes (PPROM) is its relationship to maternal and neonatal mortality and morbidity, especially in twin pregnancies. The aim of this study was to determine and compare the role of inflammatory factors as predictors of the PPROM outcome between singleton and twin pregnancies. Methods:, The medical records of 22 twins delivered between 28 and 34 weeks and complicated by PPROM were reviewed at the Al-Zahra Hospital in Tabriz, Iran. Also among singletons, 55 cases of matched gestational age were randomly selected as a control group. Three laboratory indices of neonatal white blood cell (WBC) count and C-reactive protein (CRP) in the two groups were measured immediately after delivery and the effects of two factors on neonatal outcome were assessed. Results:, In singletons, there was adverse relationship between the mean of WBC count and duration of latency (P = 0.007). Also, a positive relationship between the means of ventilation time and WBC count in second twins was found (P = 0.034). Positive CRP was the main predictor of neonatal intensive care unit admission in both singletons (odds ratio: 4.929, P = 0.042) and first twins (odds ratio: 9.000, P = 0.005). However, positive CRP did not influence the existence of metabolic acidosis or duration of latency in either of the two groups. Conclusion:, Neonatal WBC count was a predictor for the duration of latency in singletons and for ventilation time in twins. Positive neonatal CRP was an important factor for the prediction of neonatal intensive care unit admission in both types of pregnancy; its role in twins is clearer than in singletons. [source]

Why All Counter-Evidence to the Critical Period Hypothesis in Second Language Acquisition Is not Equal or Problematic

LINGUISTICS & LANGUAGE COMPASS (ELECTRONIC), Issue 6 2008
Jason Rothman
That adult and child language acquisitions differ in route and outcome is observable. Notwithstanding, there is controversy as to what this observation means for the Critical Period Hypothesis' (CPH) application to adult second language acquisition (SLA). As most versions of the CPH applied to SLA claim that differences result from maturational effects on in-born linguistic mechanisms, the CPH has many implications that are amendable to empirical investigation. To date, there is no shortage of literature claiming that the CPH applies or does not apply to normal adult SLA. Herein, I provide an epistemological discussion on the conceptual usefulness of the CPH in SLA (cf. Singleton 2005) coupled with a review of Long's (2005) evaluation of much available relevant research. Crucially, I review studies that Long did not consider and conclude differently that there is no critical/sensitive period for L2 syntactic and semantic acquisition. [source]

An Examination of Affine Term Structure Models,

ASIA-PACIFIC JOURNAL OF FINANCIAL STUDIES, Issue 4 2009
Suk-Joon Byun
Abstract This paper examines the relative performance of models in the affine term structure family which includes both complete and essential affine models using Korean government bond yield data. Principal component analysis with Korean government bond yield data shows that the first three components of yields explain 97% of the total yield curve variation, and the components can be characterized as "level", "slope", and "curvature." We also estimate all three-factor affine models using a Kalman filter/quasi maximum likelihood (QML) approach. An exhaustive comparison shows that the three-factor essential affine model, A1 (3) E, in which only one factor affects the instantaneous volatility of short rates but all three factors affect the price of risk, appears to be the best model in Korea. This finding is consistent with results in Dai and Singleton (2002) and Duffee (2002) on US data and in Tang and Xia (2007) on Canadian, German, Japanese, UK and US data. [source]

Undersampling bias: the null hypothesis for singleton species in tropical arthropod surveys

JOURNAL OF ANIMAL ECOLOGY, Issue 3 2009
Jonathan A. Coddington
Summary 1Frequency of singletons , species represented by single individuals , is anomalously high in most large tropical arthropod surveys (average, 32%). 2We sampled 5965 adult spiders of 352 species (29% singletons) from 1 ha of lowland tropical moist forest in Guyana. 3Four common hypotheses (small body size, male-biased sex ratio, cryptic habits, clumped distributions) failed to explain singleton frequency. Singletons are larger than other species, not gender-biased, share no particular lifestyle, and are not clumped at 0·25,1 ha scales. 4Monte Carlo simulation of the best-fit lognormal community shows that the observed data fit a random sample from a community of ~700 species and 1,2 million individuals, implying approximately 4% true singleton frequency. 5Undersampling causes systematic negative bias of species richness, and should be the default null hypothesis for singleton frequencies. 6Drastically greater sampling intensity in tropical arthropod inventory studies is required to yield realistic species richness estimates. 7The lognormal distribution deserves greater consideration as a richness estimator when undersampling bias is severe. [source]

Mothers' and fathers' birth characteristics and perinatal mortality in their offspring: a population-based cohort study

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2010
Tone I. Nordtveit
Summary Nordtveit TI, Melve KK, Skjaerven R. Mothers' and fathers' birth characteristics and perinatal mortality in their offspring: a population-based cohort study. Paediatric and Perinatal Epidemiology 2010; 24: 282,292. There is increasing interest in the associations between parental birthweight and gestational age with their perinatal outcomes. We investigated perinatal mortality risk in offspring in relation to maternal and paternal gestational age and birthweight. We used population-based generational data from the Medical Birth Registry of Norway, 1967,2006. Singletons in both generations were included, forming 520 794 mother,offspring and 376 924 father,offspring units. Perinatal mortality in offspring was not significantly associated with paternal gestational age or birthweight, whereas it was inversely associated with maternal gestational age. A threefold increased risk in perinatal mortality was found among offspring of mothers born at 28,30 weeks of gestation relative to offspring of mothers born at term (37,43 weeks) (relative risk: 2.9, 95% CI 1.9, 4.6). There was also an overall association between maternal birthweight and offspring perinatal mortality. Relative risk for mothers whose birthweight was <2000 g was 1.5 (95% CI 1.1, 1.9), relative to mothers whose birthweight was 3500,3999 g. However, confined to mothers born at ,34 weeks of gestation, the birthweight association was not significant. Weight-specific perinatal mortality in offspring was dependent on the birthweight of the mother and the father, that is, offspring who were small relative to their mother's or father's birthweight had increased perinatal mortality. In conclusion, a mother's gestational age, and not her birthweight, was significantly associated with perinatal mortality in the offspring, while there was no such association for the father. [source]

Maternal HIV status and pregnancy outcomes in northeastern Tanzania: a registry-based study

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 5 2008
NA Habib
Objectives, The proportion of women delivering with known HIV status in sub-Saharan Africa is not well described. Risk of HIV transmission to newborns is a major concern, but there may also be increased risks for other adverse pregnancy outcomes. Design, Hospital registry. Setting, North East Tanzania (1999,2006). Population, Singletons (n= 14 444). Methods, Births were grouped by maternal HIV status and socio-demographic factors predicting HIV status, and associations between status and pregnancy outcomes were studied. Main outcome measures, Maternal HIV status, perinatal mortality, prematurity, small for gestational age (SGA), birthweight and low Apgar score. Results, The proportion of mothers with known HIV status increased from 7% before 2001 to 78% after 2004. Single motherhood, rural residence, low maternal education, maternal and paternal farming and higher paternal age were associated with unknown HIV status. About 7.4% (95% CI 6.7,8.1%) of women were HIV infected, with increased likelihood of infection with higher gravidity, single motherhood, rural residence, maternal business or farming occupations and paternal tribe. Compared with HIV-uninfected women, the untreated HIV-infected women had a higher risk of SGA births (adjusted risk ratio [ARR] 1.6; 95% CI 1.1,2.4), preterm birth (ARR 1.8; 95% CI 1.1,2.7) and perinatal death (ARR 1.9; 95% CI 0.95,3.8). Women with unknown HIV status had moderately increased risks. Treated HIV-infected women had a risk similar to that of the HIV-uninfected women for all outcomes, except for low Apgar score. Conclusion, HIV testing and infection were associated with socio-demographic factors. Untreated HIV-infected women had higher risks of adverse pregnancy outcomes, and risks were also increased for women with unknown HIV status. There is still a need to increase availability of HIV testing, education and adequate therapy for pregnant women. [source]

Breeding biology of ostriches (Struthio camelus) in the Serengeti ecosystem, Tanzania

AFRICAN JOURNAL OF ECOLOGY, Issue 3 2009
Flora J. Magige
Abstract Ostrich breeding behaviour in the Serengeti ecosystem, Tanzania was investigated for differences in laying dates between low altitude western area (WA) and high altitude eastern area (EA) populations. Ostriches in WA laid eggs significantly earlier than in EA. The differences could be attributed to topography and rainfall pattern. Reliable rains in lower altitudes ensure availability of food that in turn influences the whole process of the reproductive cycle. Clutches were contributed by several females with a nest having up to 38 eggs. We also compared the frequency of observation of predators, ostriches, nests, ,singletons' (single eggs laid randomly) and broods between the two areas. There was no significant difference between WA and EA in 1) ostrich/nest ratio, indicating similar breeding densities; 2) ostrich/predator and predator/nest ratios, indicating that predation pressure was equally high; 3) nest/singleton and predator/singleton ratios, indicating that loss of nests did not vary between areas. However, there were significantly more predators, nests and ostriches compared to broods in EA than in WA, indicating a significantly lower reproductive success in EA. Using metapopulation terminology, ostriches in EA could be regarded as a ,sink' population and those in WA as a ,source' population, but investigations over longer time-periods are needed to further resolve if this is the case. Résumé Le comportement reproducteur des autruches dans l'écosystème du Serengeti, en Tanzanie, a étéétudié pour voir les différences dans les dates de pontes entre les populations de la zone occidentale (WA) à basse altitude et de la zone orientale (EA) à plus haute altitude. Les autruches de la WA pondent significativement plus tôt que celles de l'EA. Les différences peuvent être attribuées à la topographie et au régime de la pluviosité. Les pluies fiables à plus basse altitude garantissent la disponibilité de la nourriture, ce qui influence dès lors tout le processus du cycle reproducteur. Des couvées réunissaient les ,ufs de plusieurs femelles , un nid a eu jusqu'à 38 ,ufs. Nous avons aussi comparé la fréquence d'observations de prédateurs, d'autruches, de nids, de «ingletons» (des ,ufs solitaires pondus au hasard) et de nichées entre les deux zones. Il n'y a pas de différence significative entre WA et EA pour 1) le ratio autruches/nids, ce qui indique des densités de reproduction similaires; 2) le ratio autruches/prédateurs et le ratio prédateurs/nids, ce qui indique que la pression de la prédation est aussi haute des deux côtés; et 3) le ratio nids/singletons et le ratio prédateurs/singletons, ce qui indique que la perte des nids ne variait pas entre les zones. Cependant, il y avait significativement plus de prédateurs, de nids et d'autruches par rapport aux nichées dans l'EA que dans la WA, ce qui indique une réussite de la reproduction significativement plus faible dans la EA. En utilisant la terminologie de la métapopulation, les autruches de la EA peuvent être considérées comme une population «puits» et celles de la WA comme une population «source», mais il faudrait faire des recherches de plus longue durée pour montrer si c'est bien le cas. [source]

Intrapartum fever and chorioamnionitis as risks for encephalopathy in term newborns: a case,control study

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2008
Heidi K Blume MD MPH
In this study we examined the relationship between diagnoses of isolated intrapartum fever or chorioamnionitis and the risk of encephalopathy in term newborns. We conducted a population-based, case,control study in Washington State using 1994 to 2002 linked data from the Washington State Birth Registry and the Comprehensive Hospital Abstract Reporting System (CHARS). We identified 1060 singleton, term newborns (602 males, 458 females) with International Classification of Diseases (ICD-9) diagnoses consistent with encephalopathy, and 5330 unaffected control newborns (2756 males, 2574 females). Intrapartum fever was defined by a diagnosis of intrapartum temperature of >38°C in the birth registry or CHARS databases. Chorioamnionitis was defined using ICD-9 diagnoses recorded in CHARS. We identified 2.2 cases of encephalopathy per 1000 births. Isolated intrapartum fever was associated with a 3.1-fold (95% confidence interval [CI] 2.3-4.2) increased risk of newborn encephalopathy. Chorioamnionitis was associated with a 5.4-fold (95% CI 3.6-7.8) increased risk of encephalopathy. We found that isolated intrapartum fever and chorioamnionitis were independently associated with an increased risk of encephalopathy in term infants. Our data also indicate that there is a spectrum of risk for encephalopathy in term infants exposed to intrapartum fever. Infants born to women with signs of chorioamnionitis other than isolated intrapartum fever may be at higher risk of encephalopathy than those exposed only to isolated intrapartum fever. [source]

Spider family composition and species richness patterns in two savannah habitats along the eastern coastal plain of Africa

AFRICAN JOURNAL OF ECOLOGY, Issue 2 2010
Charles R. Haddad
Abstract The spider faunas of two savannah reserves along the eastern coastal plain of Africa are compared. Species richness was higher in the tropical area, with 493 species (54 families) from Mkomazi Game Reserve, Tanzania. Species richness was also high in the subtropics, with a total of 431 species (46 families) recorded from Ndumo Game Reserve, South Africa. Spider community structure was remarkably similar in the two reserves, with Salticidae, Gnaphosidae, Thomisidae, Theridiidae and Araneidae the most species-rich families in both reserves. Eleven of the fourteen most species rich families were the same. A similar proportion of families were represented by singleton and doubleton species. A genus- and species-level comparison of ten spider families indicates that while there is considerable overlap in the generic composition of the reserves (Sorensen's Quotient of similarity: all >0.650 except Linyphiidae, 0.166; Corinnidae, 0.500) there is little overlap between the species occurring in the two sites (0.000,0.571), which was particularly evident in the more species-rich families. A comparison of diversity of 57 families in each reserve with the spider biodiversity in the two sub-regions suggests that local biodiversity is largely determined by regional biogeographical influences rather than local ecological factors. Résumé On compare ici les araignées de deux réserves de savane situées le long de la plaine côtière de l'est de l'Afrique. La richesse en espèces était plus grande dans la région tropicale, avec 493 espèces (54 familles) dénombrées dans la Mkomazi Game Reserve, en Tanzanie. La richesse en espèces était aussi élevée dans la région subtropicale, avec un total de 431 espèces (46 familles) rapportées dans la Ndumo Game Reserve, en Afrique du Sud. La structure de la communauté des araignées était remarquablement semblable dans les deux réserves, et les Salticidae, Gnaphosidae, Thomisidae, Theridiidae et les Araneidae étaient aux deux endroits les familles les plus riches en espèces. Onze des quatorze familles les plus riches en espèces étaient les mêmes. Une proportion semblable de familles n'étaient représentées que par des espèces singletons ou doubletons. Une comparaison de dix familles d'araignées au niveau du genre ou de l'espèce indique que, s'il existe un important chevauchement de la composition générique des deux réserves (quotient de similitude de Sorensen : tous > 0,650 à l'exception des Linyphiidae, 0,166, et des Corinnidae, 0,500), il y a peu de chevauchement entre les espèces qui vivent dans les deux sites (0,000,0,571), ce qui était particulièrement évident dans les familles les plus riches en espèces. Une comparaison de la diversité de 57 familles dans chaque réserve avec la biodiversité des araignées des deux sous-régions suggère que la biodiversité locale était largement déterminée par des influences biogéographiques régionales plutôt que par des facteurs écologiques locaux. [source]

Cardiothoracic ratio in the first half of pregnancy

JOURNAL OF CLINICAL ULTRASOUND, Issue 4 2004
Theera Tongsong MD
Abstract Purpose The present study was conducted to establish the nomogram of fetal cardiothoracic (C/T) ratio in the first half of normal pregnancies (eg, 11,20 weeks of gestation), using conventional sonographic techniques. Methods Two hundred thirty-eight normal pregnant women enrolled in our prenatal care were recruited into this study. All the patients had singleton fetuses whose gestational age could be accurately determined by the patient's last menstrual period and sonographic measurements. All the newborns were proven to be normal at birth. The sonographic measurements used to calculate the C/T ratio were obtained from axial scans at the level of the four-chamber view. All measurements were made by the same examiner using a single high-resolution machine. Results A total of 238 C/T ratio measurements were made. The mean C/T ratio values increased slightly with gestational age, rising from 0.38 at 11 weeks to 0.45 at 20 weeks. The mean C/T value at each gestational week was never greater than 0.50, and no fetus had a C/T ratio greater than 0.50 at 11,15 weeks of gestation. The means and 5th, 50th, and 95th percentiles of the C/T ratio were calculated for each week of gestation and the nomogram was established. Conclusions Calculation of the C/T ratio is a simple, reliable, reproducible, and time-efficient means of assessing the size of the fetal heart. By comparing the C/T ratio with the normal values presented here, physicians should be able to more easily identify cases of cardiomegaly early in their patients' pregnancies. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:186,189, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.20014 [source]

Impact of Collaborative Management and Early Admission in Labor on Method of Delivery

JOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 2 2003
Debra J. Jackson senior researcher
Objective: This study compared the effects of early admission in labor and perinatal care provider on delivery method. Higher spontaneous vaginal delivery rates for certified nurse midwives as compared with physicians have been reported in observational studies and randomized clinical trials. Certified nurse midwives, with their more expectant approach to labor management, would be expected to admit women later in labor than obstetricians. Methods: Prospective cohort study of 2,196 low-risk pregnancies, with singleton, vertex infants admitted in spontaneous labor. Independent and joint effects of perinatal care provider and cervical dilation at admission on delivery method were evaluated. Confounding was addressed using restriction and multiple regression. Results: Fewer (23.4%) women in collaborative care were admitted in early labor (< 4 cm cervical dilation) than women managed by obstetricians (95% CI =,27.6 to ,19.2). Obstetrician care had 9% to 30% fewer spontaneous vaginal deliveries. Women admitted early in labor also had 6% to 34% fewer spontaneous vaginal deliveries. Evaluation of joint effects suggested that interaction between obstetrician provider and earlier admission increased the risk of operative delivery. Conclusion: Later admission in labor (at 4 cm or greater cervical dilation) and management of perinatal care by certified nurse midwives in collaboration with obstetricians increased the rate of spontaneous vaginal delivery in low-risk women. [source]

Evaluation of D-dimer during pregnancy

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2009
Ayano Nishii
Abstract Aim:, The purpose of the present study was to elucidate the change of D-dimer and the possibility of deep vein thrombosis screening by D-dimer during pregnancy. Methods:, One thousand, one hundred and thirty-one pregnant women were enrolled in the study from April 2006 to March 2007. D-dimer was measured by latex immunoassay at 6 to 14 and 30 to 36 weeks of gestation, respectively, and the veins of the lower extremities were examined by ultrasound at 30 to 36 weeks of gestation. Results:, The mean and standard error of D-dimer was 1.1 ± 1.0 µg/mL in the first trimester and 2.2 ± 1.1 µg/mL in the third trimester, and both values were significantly higher than adult values. In addition, D-dimer significantly increased during pregnancy. D-dimer was not significantly different between singleton and twin pregnancies in the first trimester, but in the third trimester, the values of twin pregnancies were higher than singleton pregnancies (2.2 ± 1.6 vs 3.7 ± 2.5 µg/mL). The mean value of D-dimer of ultrasonographically positive women was 2.6 ± 2.0 µg/mL, which was significantly higher than the value for negative woman during the third trimester (2.2 ± 1.6 µg/mL). The positive predictive value was 7.4% and negative predictive value was 95.5% for ultrasonographically positive women when D-dimer was set at 3.2 µg/mL. Conclusion:, We clearly found a change of D-dimer during pregnancy. When D-dimer was higher than 3.2 µg/mL, the percentage of ultrasonographically positive women was high. We propose that women with D-dimer higher than 3.2 µg/mL are closely monitored for prevention of pulmonary thromboembolism. [source]

Neonatal C-reactive protein value in prediction of Outcome of Preterm Premature Rupture of Membranes: Comparison of Singleton and Twin Pregnancies

Changes of serum melatonin level and its relationship to feto-placental unit during pregnancy

JOURNAL OF PINEAL RESEARCH, Issue 1 2001
Yasuhiko Nakamura
Serum melatonin concentrations were studied in normal pregnant women and in women with several types of pathologic pregnancies, e.g., twins, preeclampsia or intrauterine growth retardation (IUGR). Blood samples were collected from the maternal antecubital vein at 14:00 hr (daytime) and 02:00 hr (nighttime) during pregnancy, and also from the umbilical vein and artery immediately after delivery. Serum melatonin concentrations were measured by radioimmunoassay. Daytime serum melatonin levels in normal (single fetus; singleton) pregnancies were low. While the levels showed an increasing tendency toward the end of pregnancy, no statistically significant changes occurred. On the other hand, the nighttime serum melatonin levels increased after 24 weeks of gestation, with significantly (P<0.01) high levels after 32 weeks; these values decreased to non-pregnant levels on the 2nd day of puerperium. Nighttime serum melatonin levels were significantly (P<0.05) higher in twin pregnancies after 28 weeks of gestation than in singleton pregnancies, whereas the patients with severe preeclampsia showed significantly (P<0.05) lower serum melatonin levels than the mild preeclampsia or the normal pregnant women after 32 weeks of gestation. Melatonin concentrations in umbilical vessels showed a higher tendency in neonates who were born during at night compared with the other neonates; moreover, those in the umbilical artery were generally higher than those in the umbilical vein. The present results indicate that in humans, the maternal serum melatonin levels show a diurnal rhythm, which increases until the end of pregnancy, reflecting some pathologic states of the feto-placental unit. Fetuses may produce melatonin with a circadian rhythm. [source]

Auricular anthropometry of Hong Kong Chinese babies

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 1 2004
T.F. Fok
Structured Abstract Authors , Fok TF, Hon KL, So HK, Wong E, Ng PC, Lee AKY, Chang A Objectives , To provide a database of the auricular measurements of Chinese infants born in Hong Kong. Design , Prospective cross-sectional study. Setting and Sample Population , A total of 2384 healthy singleton, born consecutively at the Prince of Wales Hospital and the Union Hospital from October 1998 to September 2000, were included in the study. The range of gestation was 33,42 weeks. Measurements and Results , Measurements included ear width (EW), ear length (EL) and ear position (EP). The data show generally higher values for males in the parameters measured. When compared with previously published data for Caucasian and Jordanian term babies, Chinese babies have shorter EL. The ears were within normal position in nearly all our infants. Conclusion , The human ear appears to grow in a remarkably constant fashion. This study establishes the first set of gestational age,specific standard of the ear parameters for Chinese new-borns, potentially enabling early syndromal diagnosis. There are significant inter-racial differences in these ear parameters. [source]

Disparities in the prevalence of cognitive delay: how early do they appear?

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 3 2009
Marianne M. Hillemeier
Summary Cognitively delayed children are at risk for poor mental and physical health throughout their lives. The economically disadvantaged and some race/ethnic groups are more likely to experience cognitive delay, but the age at which delays first emerge and the underlying mechanisms responsible for disparities are not well understood. The objective of this study was to determine when sociodemographic disparities in cognitive functioning emerge, and identify predictors of low cognitive functioning in early childhood. Data were from 7308 singleton and 1463 multiple births in the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a nationally representative cohort of children born in the USA in 2001. Multiple logistic regression analyses examined associations between sociodemographic characteristics and low cognitive functioning at 9 and 24 months, and tested whether gestational and birth-related factors mediate these associations. Sociodemographic characteristics were statistically significant predictors of low cognitive functioning among singletons at 24 months, including the three lowest quintiles of socio-economic status [lowest quintile, odds ratio (OR) = 2.7, 95% confidence interval [CI][1.7, 4.1]], non-white race/ethnicity (African American OR = 1.8 [95% CI 1.3, 2.5], Hispanic OR = 2.3 [95% CI 1.6, 3.2]), and gender (male OR = 2.1, [95% CI 1.7, 2.5]). Gestational and birth characteristics associated with low cognitive function at 9 months included very low and moderately low birthweight (OR = 55.0 [95% CI 28.3, 107.9] and OR = 3.6 [95% CI 2.6, 5.1]), respectively, and very preterm and moderately preterm delivery (OR = 3.6 [95% CI 2.0, 6.7] and OR = 2.4 [95% CI 1.7, 3.5]), respectively, but they had weaker effects by 24 months (ORs for birthweight: 3.7 [95% CI 2.3, 5.9] and 1.8 [95% CI 1.4, 2.3]; ORs for preterm: 1.8 [95% CI 1.1, 2.9] and 0.9 [95% CI 0.7, 1.3]). Results for multiple births were similar. Sociodemographic disparities in poor cognitive functioning emerged by 24 months of age, but were not mediated by gestational or birth characteristics. Further investigation of processes whereby social disadvantage adversely affects development prior to 24 months is needed. [source]

Fetal growth and neonatal mortality in Korea

PAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 5 2007
Jae S. Hong
Summary The fetal growth curve and neonatal mortality rate, based on gestational age and birthweight, are important for identifying groups of high-risk neonates and developing appropriate medical services and health-care programmes. The purpose of this study was to develop a national fetal growth curve for neonates in Korea, and examine the Korean national references for fetal growth and death according to their characteristics. Data of Korean vital statistics linked National Infant Mortality Survey conducted on births in 1999 were used in this study. The total livebirths were 621 764 in 1999, which were grouped into singletons (n = 609 643) and twins (n = 9805) for analysis. Birthweight/gestational age-specific fetal growth curves and neonatal mortality rates were based on 250 g of birthweight and weekly gestational age intervals for each characteristic of the birth. The features of high-risk neonates such as small-for-gestational-age and the limit of viability in Korea were different from those of Western countries. Difference in fetal growth and death was also detected in other characteristics of the fetus (gender and plurality of birth) besides race. The fetal growth curve of males was higher than that of females, and was higher in singleton than in twins. The neonatal mortality rate was higher in males (singleton, 2.6; twin, 23.5) than females (singleton, 2.1; twin, 15.9), and higher in twins (19.8/1000) than in singletons (2.4/1000). However, in neonates with gestational age >29 weeks and birthweight >1000 g, the neonatal mortality rate was lower in twins than in singletons. The limit of viability was gestational age 27 weeks and birthweight 1000 g, which was similar in singletons and twins regardless of gender. To improve the health of neonates in a country, it is imperative to investigate the characteristics of fetal growth and death under the particular circumstances of the country. When risk is defined for neonates account must be taken of differences in race, gender and plurality of birth, as the neonatal mortality rate varies depending on those factors. [source]

Parental exposure to lead and small for gestational age births

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 6 2006
Pau-Chung Chen MD
Abstract Background Previous studies about the effect of lead exposure on adverse birth outcomes are still inconsistent and few studies estimate the relationship between parental lead exposure and small for gestational age (SGA) infants. An occupational cohort study to assess whether parental lead exposure would be related to decreased birth weight and shortened gestational ages of their offspring was conducted. Whether higher lead exposure doses would increase risks of low birth weight (LBW), preterm delivery, and SGA births was also investigated. Methods A Program to Reduce Exposure by Surveillance System,Blood Lead Levels (Press-BLLS) was established in Taiwan in July 1993. The names of workers exposed to lead was collected from this occupational blood-lead notification database. The birth outcomes of their offspring were determined by linking to the Taiwan birth registration database from 1993 to 1997. Only singleton births whose parental blood-lead concentrations were tested during pregnancy or prior to conception, or within a 1-year span before these two periods were included. Results Among 1,611 eligible births, 72 births were LBW, 74 were preterm deliveries, and 135 were SGA. Maternal blood-lead concentrations (PbBs) equal to or more than 20 µg/dl had a higher risk of mothering a SGA child (risk ratio (RR),=,2.15; 95% confidence interval (CI), 1.15,3.83). Conclusions Additional evidence of the effects of lead on adverse birth outcomes, especially for SGA births is reported. Maternal exposure to lead plays a more important role in the adverse effect on birth outcome than does paternal exposure. Am. J. Ind. Med. 2006. © 2006 Wiley-Liss, Inc. [source]

Is chorionic villus sampling associated with hypertensive disorders of pregnancy?

PRENATAL DIAGNOSIS, Issue 1 2010
Anthony O. Odibo
Abstract Objective Our objective is to evaluate for potential associations between chorionic villus sampling (CVS) and hypertensive disorders of pregnancy. Methods Using our genetic database, we compared the rates of hypertensive disorders between women who underwent CVS at 10,13 and 6/7 weeks with those seen for other indications at similar gestational ages who had no invasive procedure. Only singleton and euploid pregnancies were included. Statistical methods including univariable and multivariable logistic regression, supplemented by stratified analyses were used for comparisons. Results Among 11 012 pregnant women seen between 1990 and 2006 in our center and meeting the inclusion criteria, information on hypertensive disorders of pregnancy were available in 9386, and 9098 met the inclusion criteria. The overall incidence of hypertensive disorders was 421/9098 (4.6%), with 138/5096 (2.7%) in the CVS group and 283/4002 (7.1%) in the control group [adjusted odds ratio (adjOR) 0.47, 95% confidence interval (CI), 0.38,0.59]. Similar findings were seen on stratified analyses for gestational age of procedure and the type or severity of hypertensive disorder, and other potential confounders. Conclusion The rate of hypertensive disorders of pregnancy is significantly lower in women having CVS compared with the control group. Placental disruption from CVS is not associated with preeclampsia or gestational hypertension. Copyright © 2009 John Wiley & Sons, Ltd. [source]

First-trimester maternal serum PAPP-A, SP1 and M-CSF levels in normal and trisomic twin pregnancies

PRENATAL DIAGNOSIS, Issue 2 2003
N. A. Bersinger
Abstract Objective To study PAPP-A and SP1 for biochemical trisomy screening in twin pregnancies and to investigate the role of maternal and placental compartments in marker production by comparing the levels of the decidual cytokine M-CSF with the PAPP-A and SP1 from the placenta. Methods Thirteen twin pregnancies with at least one chromosomally abnormal fetus were compared with 68 normal twin pregnancies. Sera were obtained between 11 + 3 and 13 + 6 weeks of gestation, and PAPP-A, SP1 and M-CSF levels were determined by immunoassay. These concentrations were also compared with gestation-matched groups of 18 singleton normal pregnancies and 18 singleton Down syndrome pregnancies. Results PAPP-A and SP1, but not M-CSF, levels were higher in normal twin pregnancy than in normal singleton pregnancy. SP1 levels, but not PAPP-A, correlated to M-CSF. PAPP-A, but not SP1, levels were reduced in abnormal twin pregnancies, with an increasing effect according to the number of affected fetuses, and were more pronounced in pregnancies with trisomy 18 or 13 than in trisomy 21 fetuses. M-CSF was inconsistent, with a trend towards increased levels in trisomy 21. Conclusion PAPP-A remains the best biochemical screening marker for fetal trisomies 21, 18 or 13, in singleton as well as in twin pregnancy. In contrast to SP1, its site of production is not likely to be restricted to the placenta. The role of the (maternally produced) M-CSF remains to be further investigated. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Cluster synchronization, switching and spatiotemporal coding in a phase oscillator network

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2007
Gábor Orosz
A network of five globally-coupled identical phase oscillators is considered. Cluster states consisting of two synchronized pairs of oscillators and one singleton are investigated. Forcing the system with non-uniform constant inputs results in regular switches between cluster states. The resultant cyclic sequences of switches (spatiotemporal codes) are studied for different initial conditions and input configurations. Implications on information coding in neural systems are briefly discussed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Dimension-based attention modulates early visual processing

PSYCHOPHYSIOLOGY, Issue 5 2010
Klaus Gramann
Abstract Target selection can be based on spatial or dimensional/featural mechanisms operating in a location-independent manner. We investigated whether dimension-based attention affects processing in early visual stages. Subjects searched for a singleton target among an 8-item array, with the search display preceded by an identical cue array with a dimensionally non-predictive, but spatially predictive singleton. Reaction times (RTs) were increased for changes in the target-defining dimension but not for featural changes within a dimension. This RT effect was mirrored by modulations of the P1 and anterior transition N2 (tN2). Current density reconstructions revealed increased activity in dorsal occipital cortex and decreased activity in left frontopolar cortex owing to repeated dimensional pop-out identities. These findings strengthen dimension-based theories of visual attention by indicating dimension-, rather than feature-, specific influences within the first 110 ms of visual processing. [source]

Comparison of PERV genomic locations between Asian and European pigs

ANIMAL GENETICS, Issue 1 2010
W. Y. Jung
Summary Xenotransplantation from pigs provides a possible solution to the shortage of human organs for allotransplantation. Porcine endogenous retroviruses (PERVs) are a possible obstacle to using porcine organs in addition to the immunological barriers. Three main types of PERVs (A, B and C) have been previously investigated in diverse pig breeds. To examine the copy numbers of PERVs and their genomic locations in the Korean native pig genome, we screened a BAC (Bacterial Artificial Chromosome) library with PERV-specific protease primers for initial recognition of PERV-positive clones and three sets of envelope-specific primers for the identification of PERV types. A total of 45 PERV-positive clones, nine PERV-A and 36 PERV-B, have been identified from the library screening and the BAC contigs were constructed using the primers designed from BAC end sequences (BESs). These primers were also used for SCH (Somatic Cell Hybrid) and RH (Radiation Hybrid) mapping of the PERV-positive clones. The results indicate that 45 PERV-positive BAC clones belong to nine contigs and a singleton. SCH and IMpRH (INRA-Minnesota Porcine Radiation Hybrid) mapping results indicated that there are at least eight separate PERV genomic locations, consisting of three PERV-A and five PERV-B. One contig could not be mapped, and two contigs are closely located on SSC7. Southern blotting indicates there may be up to 15 additional sites. Further investigation of these clones will contribute to a general strategy to generate PERV-free lines of pigs suitable for xenotransplantation. [source]

Watchful waiting: A management protocol for maternal glycaemia in the peripartum period

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 2 2009
Helen Lorraine BARRETT
Background: It is accepted that tight glycaemic control is necessary during labour in women with pregestational or gestational diabetes mellitus (GDM). Although policies vary, routine use of intravenous glucose and insulin remains a standard practice in some institutions. We present a retrospective review of a more conservative approach. Briefly, regardless of planned delivery method, maternal blood sugar level (BSL) is monitored during delivery and only if outside 4,7 mmol/L is action taken. We report the results of an audit of this practice. Methods: A retrospective (August 2001,July 2004) review of 137 singleton, term deliveries of women with diabetes (23 pregestational, 114 GDM). Predetermined outcomes reported were BSL achieved prior to delivery, first neonatal BSL and/or admission to neonatal intensive care unit (NICU) for hypoglycaemia. Results: With our management practice, most women had a BSL between 4 and 8 mmol/L prior to delivery (17 (74%) diabetes mellitus (DM), 37 (93%) diet-controlled GDM, 55 (89%) insulin-requiring GDM). Neonatal hypoglycaemia (< 2.6 mmol/L) was common (n= 30 (22%)). However, most neonatal hypoglycaemia occurred in infants born to mothers with BSL 4,8 mmol/L (n= 26 (87%)). Neonatal hypoglycaemia requiring NICU admission (n= 13) was predominantly in infants born to mothers with BSL < 8mmol/L prior to delivery (n= 10 (77%)). Three of eight maternal BSLs > 8 mmol/L occurred prior to emergency caesarean section in women with pregestational diabetes. Conclusion: These results suggest that our current practice, particularly in women with GDM, may offer an alternative to more aggressive regimes. [source]

The effect of single or multiple courses of antenatal corticosteroid therapy on neonatal respiratory distress syndrome in singleton versus twin pregnancies

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 2 2009
Suk-Joo CHOI
Background: Antenatal corticosteroid (ACS) treatment is widely used for the prevention of respiratory distress syndrome (RDS) in preterm infants. However, the efficacy and safety of ACS treatment remains controversial in twin pregnancies. Aims: To investigate the effect of ACS therapy, single or multiple courses, on the incidence of neonatal RDS in singleton and twin pregnancies. Methods: We retrospectively evaluated the pregnancy and neonatal outcomes of 450 singleton and 117 twin pregnancies delivered at 24,34 weeks of gestation due to preterm labour or preterm premature rupture of membranes. The subjects were categorised into four groups according to ACS exposure: 0, 1, 2 and , 3 courses. Results: Overall, RDS occurred more frequently in twins compared to singletons (41.0% vs 25.3%, P < 0.001). In singleton pregnancy, the incidence of RDS was significantly lower in the ACS user groups than in the non-user group, with the lowest incidence in the multiple course groups. An increase in the number of courses of ACS was associated with a reduction in the incidence of RDS (odds ratio 0.349, 95% confidence interval 0.226, 0.537, P < 0.001) independent of confounding variables. In twin pregnancies, however, the incidence of RDS was not significantly different in comparisons among the four groups. Conclusion: Multiple courses of ACS were associated with a significantly decreased risk of RDS in singleton pregnancies. However, the current standard dose or interval for ACS administration in singleton pregnancy, as either a single or multiple courses, did not reduce RDS in twins. [source]

A new way of looking at Caesarean section births

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 4 2007
Fergus P. McCARTHY
Abstract Aims:, To implement the Robson Ten Group Classification System (TGCS) at the Royal Women's Hospital (RWH), Melbourne, in order to determine the main contributors to the rising Caesarean section (CS) rate. Methods:, The TGCS divides women into ten groups according to parity, past obstetric history, singleton or multiple pregnancy, fetal presentation, gestational age and mode of onset of labour/delivery. The TGCS was applied retrospectively to the population of women who had a registered birth at the RWH between January 2005 and 31 December 2005. Results:, A total of 5833 women gave birth to 6011 babies during the study period. A total of 1651 women (28.3%) had a CS birth. The total CS rates ranged from 3.7% (group 3) to 100% (group 9). Women in groups 1 and 2 were the greatest contributors to the emergency CS rate, 4.2% and 4.9%, respectively. Women in group 5 were the single greatest contributor to both the elective CS rate and the total CS rate. Conclusions:, The TGCS was successfully implemented at the RWH in 2005. The TGCS is ongoing, enabling monitoring of CS rates. The Robson TGCS demonstrates the need to focus on the care of women in groups 1, 2 and 5 in particular, if CS rates are to be reduced. [source]

Outcome of pregnancies achieved by in vitro fertilisation techniques and diagnosed as twins at the 6 week ultrasound

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 6 2004
Gabor T. KOVACS
Abstract Background: To bring the success rate of in vitro fertilisation (IVF) procedures to an acceptable level, multiple embryos have historically been replaced. This has resulted in an ,epidemic' of multiple births. The pendulum has now swung full circle and the number of embryos transferred is now being limited. Such high numbers of IVF twins will not be produced in the future. Aim: To review retrospectively the outcome of a series of pregnancies achieved by IVF where the 6 week ultrasound showed the presence of two sacs. Methods: Retrospective study in a university IVF programme that produced 746 IVF pregnancies with twins at 6 weeks of gestation (1991,1999). Results: The main outcome measures were perinatal mortality, pregnancy outcome, gestation at delivery and obstetrics complications reported. Interestingly, by 20 weeks gestation, 184 (24.7%) of pregnancies spontaneously reduced to a singleton, whereas 49 (6.6%) lost both twins. Of the 513 (68.8%) viable twin pregnancies (>20 weeks), 154 (20.6%) went on to term (>37 weeks), whereas 250 (33.5%) delivered between 33 and 36 weeks gestation. The perinatal mortality per 1000 births was 6.5 over 37 weeks, 8.0 for 33,36 weeks, 41.7 for 29,32 weeks and 500 for under 28 weeks. [source]

ELECTIVE TWIN REDUCTIONS: EVIDENCE AND ETHICS

BIOETHICS, Issue 6 2010
LEAH MCCLIMANS
ABSTRACT Twelve years ago the British media got wind of a London gynecologist who performed an elective reduction on a twin pregnancy reducing it to a singleton. Perhaps not surprisingly, opinion on the moral status of twin reductions was divided. But in the last few years new evidence regarding the medical risks of twin pregnancies has emerged, suggesting that twin reductions are relevantly similar to the reductions performed on high-end multi-fetal pregnancies. This evidence has appeared to resolve the moral debate. In this paper I look at the role of clinical evidence in medical ethics. In particular I examine the role of clinical evidence in determining what counts as a significant harm or risk. First, I challenge the extent to which these empirical claims are descriptive, suggesting instead that the evidence is to some degree normative in character. Second, I question whether such empirical claims should count as evidence for what are essentially difficult ethical decisions , a role they appear to play in the case of elective reductions. I will argue that they should not, primarily because the value-laden nature of this evidence conceals much of what is ethically at stake. It is important to recognize that empirical evidence cannot be a substitute for ethical deliberation. [source]

Structure of the minimized ,/,-hydrolase fold protein from Thermus thermophilus HB8

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 12 2007
Yong Xie
The gene encoding TTHA1544 is a singleton found in the Thermus thermophilus HB8 genome and encodes a 131-amino-acid protein. The crystal structure of TTHA1544 has been determined at 2.0,Å resolution by the single-wavelength anomalous dispersion method in order to elucidate its function. There are two molecules in the asymmetric unit. Each molecule consists of four ,-helices and six ,-strands, with the ,-strands composing a central ,-sheet. A structural homology search revealed that the overall structure of TTHA1544 resembles the ,/,-hydrolase fold, although TTHA1544 lacks the catalytic residues of a hydrolase. These results suggest that TTHA1544 represents the minimized ,/,-hydrolase fold and that an additional component would be required for its activity. [source]