Effective Circle Count for Apollonian packings and Closed horospheres

The main result of this paper is an effective count for Apollonian circle packings that are either bounded or contain two parallel lines. We obtain this by proving an effective equidistribution of closed horospheres in the unit tangent bundle of a geometrically finite hyperbolic 3-manifold of infinite volume, whose fundamental group has critical exponent bigger than 1. We also discuss applications to Affine sieves. Analogous results for surfaces are treated as well.Comment: 43 pages, 2 figures, To appear in GAF

Macroblock-based algorithm for dual-bitstream MPEG video streaming with VCR functionalities

Centre for Multimedia Signal Processing, Department of Electronic and Information EngineeringVersion of RecordPublishe

Preeclampsia in pregnancy and later use of antihypertensive drugs

We explored the association between preeclampsia and later use of antihypertensive drugs in a population-based study with data from the Medical Birth Registry of Norway and the Norwegian Prescription Database. The study cohort consisted of 980,000 women having 2.1 million pregnancies during 1967–2012. Hazard ratios (HRs) with 95 % confidence intervals (95 % CI) were estimated in multivariate time-dependent Cox proportional hazards regression models. Overall, the HR of later use of antihypertensive drugs was 2.0 (95 % CI 2.0–2.0) in women with one preeclamptic pregnancy compared to women without preeclamptic pregnancies. The HR increased by increasing number of preeclamptic pregnancies, both term and preterm pregnancies. In women with two or more preeclamptic pregnancies, the HR was 2.8 (2.7–3.0). The overall HR after 40 years of follow-up for women with one preeclamptic pregnancy was 1.3 (1.2–1.4) and for two or more preeclamptic pregnancies the HR was 1.6 (1.1–2.1). The first 5 years after the first birth, the HR of being dispensed antihypertensive drugs was higher in preterm [8.4 (7.7–9.1)] than term preeclamptic pregnancies [4.3(4.0–4.6)]. However, after 10 years, this difference was no longer present. The HR of later use of antihypertensive drugs increased with the number of preeclamptic pregnancies, and in the first 10 years the HR was higher after a preterm than a term preeclamptic pregnancy. Although the HR decreased with time since first birth, the risk was still elevated after 40 years. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited

Anal incontinence after vaginal delivery or cesarean section.

INTRODUCTION: Uncertainties remain as to whether cesarean section is protective for short and long term development of anal incontinence. Our aim was to explore whether women who had only delivered vaginally were at greater risk of anal incontinence compared to nulliparous women and women who had undergone caesarean sections only. MATERIAL AND METHODS: Background information, medical history and data on anal incontinence (defined as fecal or flatus incontinence weekly or more) reported by women participating in a large population-based health survey in Norway (HUNT 3) during the period October 2006-June 2008, was collected and linked to data from the Medical Birth Registry of Norway. Anal incontinence prevalence was calculated and multivariable logistic regression analyses were applied. RESULTS: Mean age amongst the 12.567 women was 49.9 years. Age and educational level were similar in women with caesarean sections only and those with vaginal delivery and obstetric anal sphincter injuries (OASIS). Nulliparas and women with vaginal delivery and no OASIS were older and had higher educational achievements. One in four women with OASIS reported anal incontinence compared to one in six amongst the other women(p<.001). Age, educational level, diarrhea, constipation, birthweight and OASIS increased the risk of anal incontinence in all women. Parity was associated with anal incontinence in parous women only. No differences were found for fecal urgency. CONCLUSIONS: Women with vaginal deliveries complicated by OASIS were at increased risk of anal incontinence. However, no increased risk of anal incontinence was found in nulliparous women or women with cesarean sections only or vaginal deliveries not complicated by OASIS

Sexual violence and neonatal outcomes: a Norwegian population-based cohort study

Objective The objective of this study was to explore the association between sexual violence and neonatal outcomes. Design National cohort study. Setting Women were recruited to the Norwegian Mother and Child Cohort Study (MoBa) while attending routine ultrasound examinations from 1999 to 2008. Population A total of 76 870 pregnant women. Methods Sexual violence and maternal characteristics were self-reported in postal questionnaires during pregnancy. Neonatal outcomes were retrieved from the Medical Birth Registry of Norway (MBRN). Risk estimations were performed with linear and logistic regression analysis. Outcome measures: gestational age at birth, birth weight, preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA). Results Of 76 870 women, 18.4% reported a history of sexual violence. A total of 4.7% delivered prematurely, 2.7% had children with a birth weight <2500 g and 8.1% children were small for their gestational age. Women reporting moderate or severe sexual violence (rape) had a significantly reduced gestational length (2 days) when the birth was provider-initiated in an analysis adjusted for age, parity, education, smoking, body mass index and mental distress. Those exposed to severe sexual violence had a significantly reduced gestational length of 0.51 days with a spontaneous start of birth. Crude estimates showed that severe sexual violence was associated with PTB, LBW and SGA. When controlling for the aforementioned sociodemographic and behavioural factors, the association was no longer significant. Conclusions Sexual violence was not associated with adverse neonatal outcomes. Moderate and severe violence had a small but significant effect on gestational age; however, the clinical influence of this finding is most likely limited. Women exposed to sexual violence in this study reported more of the sociodemographic and behavioural factors associated with PTB, LBW and SGA compared with non-abused women

Perinatal mortality by gestational week and size at birth in singleton pregnancies at and beyond term: a nationwide population-based cohort study

Background: Whether gestational age per se increases perinatal mortality in post-term pregnancy is unclear. We aimed at assessing gestational week specific perinatal mortality in small-for-gestational-age (SGA) and non-SGA term and post-term gestations, and specifically to evaluate whether the relation between post-term gestation and perinatal mortality differed before and after ultrasound was introduced as the standard method of gestational age estimation. Methods: A population-based cohort study, using data from the Medical Birth Registry of Norway (MBRN), 1967–2006, was designed. Singleton births at 37 through 44 gestational weeks (n = 1 855 682), excluding preeclampsia, diabetes and fetal anomalies, were included. Odds ratios (OR) with 95% confidence intervals (CI) for perinatal mortality and stillbirth in SGA and non-SGA births by gestational week were calculated. Results: SGA infants judged post-term by LMP had significantly higher perinatal mortality than post-term non-SGA infants at 40 weeks, independent of time period (highest during 1999–2006 [OR 9.8, 95% CI: 5.7-17.0]). When comparing years before (1967–1986) versus after (1987–2006) ultrasound was introduced, there was no decrease in the excess mortality for post-term SGA versus non-SGA births (ORs from 6.1 [95% CI: 5.2-7.1] to 6.7 [5.2-8.5]), while mortality at 40 weeks decreased significantly (ORs from 4.6, [4.0-5.3] to 3.2 [2.5-3.9]). When assessing stillbirth risk (1999–2006), more than 40% of SGA stillbirths (11/26) judged to be ≥41 weeks by LMP were shifted to lower gestational ages using ultrasound estimation. Conclusions: Mortality risk in post-term infants was strongly associated with growth restriction. Such infants may erroneously be judged younger than they are when using ultrasound estimation, so that the routine assessment for fetal wellbeing in the prolonged gestation may be given too late

Hyperemesis gravidarum in the Medical Birth Registry of Norway – a validity study

BACKGROUND: Valid registration of medical information is essential for the quality of registry-based research. Hyperemesis gravidarum (HG) is characterized by severe nausea and vomiting, weight loss and electrolyte imbalance starting before 22nd gestational week. Given the fact that HG is a generally understudied disease which might have short- and long- term health consequences for mother and child, it is of importance to know whether potential misclassification bias influences the results of future studies. We therefore assessed the validity of the HG-registration in the in Medical Birth Registry of Norway (MBRN) using hospital records. METHODS: The sample comprised all women registered in MBRN with HG and who delivered at Ullevål and Akershus hospitals in 1.1.-31.3.1970, 1.4.-30.6.1986, 1.7.-30.9.1997 and 1.10.-31.12.2001. A random sample of 10 women per HG case, without HG according to MBRN, but who delivered during the same time periods at the same hospitals was also collected. The final sample included 551 women. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were estimated using strict and less strict diagnostic criteria of HG, indicating severe and mild HG, respectively. Hospital journals were used as gold standard. RESULTS: Using less strict diagnostic criteria of HG, sensitivity, specificity, PPV and NPV were 83.9% (95% CI: 67.4-92.9), 96.0% (95% CI: 93.9-97.3), 55.3% (95% CI: 41.2-68.6) and 99.0% (95% CI: 97.7-99.6), respectively. For strict diagnostic criteria, being hospitalised due to HG the corresponding values were 64% (95% CI: 38.8-87.2), 92% (95% CI: 90.2-94.6), 18.6% (95% CI: 10.2-31.9) and 99.0% (95% CI: 97.7-99.6). CONCLUSIONS: The results from our study are comparable to previous research on disease registration in MBRN, and show that MBRN can be considered valid for mild HG but not for severe HG

Improving Information on Maternal Medication Use by Linking Prescription Data to Congenital Anomaly Registers: A EUROmediCAT Study

Research on associations between medication use during pregnancy and congenital anomalies is significative for assessing the safe use of a medicine in pregnancy. Congenital anomaly (CA) registries do not have optimal information on medicine exposure, in contrast to prescription databases. Linkage of prescription databases to the CA registries is a potentially effective method of obtaining accurate information on medicine use in pregnancies and the risk of congenital anomalies. We linked data from primary care and prescription databases to five European Surveillance of Congenital Anomalies (EUROCAT) CA registries. The linkage was evaluated by looking at linkage rate, characteristics of linked and non-linked cases, first trimester exposure rates for six groups of medicines according to the prescription data and information on medication use registered in the CA databases, and agreement of exposure. Of the 52,619 cases registered in the CA databases, 26,552 could be linked. The linkage rate varied between registries over time and by type of birth. The first trimester exposure rates and the agreements between the databases varied for the different medicine groups. Information on anti-epileptic drugs and insulins and analogue medicine use recorded by CA registries was of good quality. For selective serotonin reuptake inhibitors, anti-asthmatics, antibacterials for systemic use, and gonadotropins and other ovulation stimulants, the recorded information was less complete. Linkage of primary care or prescription databases to CA registries improved the quality of information on maternal use of medicines in pregnancy, especially for medicine groups that are less fully registered in CA registries