Maternal factors and the risk of birth defects after IVF and ICSI: a whole of population cohort study.

OBJECTIVE: To assess the contribution of maternal factors to major birth defects after in vitro fertilisation (IVF), intracytoplasmic sperm injection (ICSI), and natural conception. DESIGN: Retrospective cohort study in South Australia for the period January 1986 to December 2002. SETTING: A whole of population study. POPULATION: A census of all IVF and ICSI linked to registries for births, pregnancy terminations, and birth defects (diagnosed before a child's fifth birthday). METHODS: Odds ratios (ORs) for birth defects were calculated among IVF, ICSI, and natural conceptions for maternal age, parity, pre-pregnancy BMI, smoking, pre-existing diseases, and conditions in pregnancy, with adjustment for confounding factors. MAIN OUTCOME MEASURES: Birth defects classified by International Classification of Diseases (ninth revision) and British Paediatric Association (ICD9-BPA) codes. RESULTS: There were 2211 IVF, 1399 ICSI, and 301 060 naturally conceived births. The unadjusted prevalence of any birth defect was 7.1, 9.9, and 5.7% in the IVF, ICSI, and natural conception groups, respectively. As expected, the risk of birth defects increased with maternal age among the natural conceptions. In contrast, for IVF and ICSI combined, relative to natural conceptions, births to women aged ≤29 years had a higher risk (adjusted odds ratio, aOR 1.42; 95% confidence interval, 95% CI 1.04-1.94), births to women aged 35-39 years had no difference in risk (aOR 1.01; 95% CI 0.74-1.37), and births to women aged ≥40 years had a lower risk of defects (aOR 0.45; 95% CI 0.22-0.92). Defects were also elevated for nulliparity, anaemia, and urinary tract infection in births after ICSI, but not after IVF. CONCLUSIONS: The usual age-birth defect relationship is reversed in births after IVF and ICSI, and the associations for other maternal factors and defects vary between IVF and ICSI. TWEETABLE ABSTRACT: Risk of birth defects in women over 40 years is lower after infertility treatment than for natural conceptions.

Birthweight and thinness at birth independently predict symptoms of polycystic ovary syndrome in adulthood.

BACKGROUND: The aetiology of polycystic ovary syndrome (PCOS) is unknown and contested. While it has been suggested that PCOS could have origins in perturbed development, epidemiological findings have been inconclusive. We aimed to examine potential fetal origins of PCOS. METHODS: A retrospective birth cohort of 948 singleton female babies born at one hospital in South Australia in 1973-1975 was assembled. Birth characteristics were obtained from hospital records and PCOS symptoms were identified through interview and clinical examination when women were ~30 years old. Based on the combination of PCOS symptoms, women formed seven outcome groups. A multinomial logistic regression analysis was used to investigate associations between birth characteristics and these outcome groups. RESULTS: After adjusting for gestational age, two distinct birth characteristics were associated with two PCOS symptom groups. Each 100 g increase in birthweight increased the risk of hyperandrogenism (as a single symptom) in adulthood by 5% [relative risk ratio: 1.05, 95% confidence interval (CI): 1.01-1.09]. In contrast, each one unit increase in the ponderal index at birth decreased the risk of all three key PCOS symptoms (hyperandrogenism, menstrual dysfunction and polycystic ovaries) by 21% (0.79, 95% CI: 0.66-0.93). CONCLUSIONS: These results suggest two discrete fetal programming pathways (related to high birthweight and to thinness at birth) are operating. Our findings point to differing aetiologies for symptom clusters, and inform the debate over symptoms that best represent the disorder.

Effects of central administration of insulin or l-NMMA on rat skeletal muscle microvascular perfusion.

AIM: Intracerebroventricular (ICV) administration of a nitric oxide synthase (NOS) inhibitor to rats has been reported to raise blood pressure (BP) and cause insulin resistance, suggestive of a central effect of insulin that is NO dependent. Herein we test whether ICV insulin has peripheral haemodynamic and metabolic effects and whether peripheral effects of systemic insulin are affected by the ICV administration of the NOS inhibitor N(G) -methyl-l-arginine (l-NMMA). METHODS: Anaesthetized rats were fitted with an ICV cannula for insulin, artificial cerebrospinal fluid (aCSF) or l-NMMA infusion. Rats receiving ICV l-NMMA (500 µg) underwent systemic insulin clamp (10 mU/min/kg) or saline treatment for 70 min and were compared with animals receiving an equal amount of l-NMMA infused systemically. RESULTS: ICV aCSF or insulin (135 mU/min/kg brain) for 70 min or systemic l-NMMA (500 µg) had no effect on BP, heart rate (HR), femoral blood flow (FBF), glucose infusion rate, muscle 2-deoxyglucose uptake, microvascular perfusion or plasma insulin. However, ICV l-NMMA reduced systemic insulin-mediated increases in FBF (2.05 ± 0.08 to 1.55 ± 0.15 ml/min), 2-deoxyglucose uptake (17.7 ± 0.15 to 10.0 ± 0.03 µg/g/min) and microvascular perfusion (10.5 ± 0.5 to 6.6 ± 1.1 mol/min) (each mean ± SE, p < 0.05); plasma insulin, HR and BP were unaffected. CONCLUSIONS: Central insulin administration had no effect on skeletal muscle haemodynamics or glucose metabolism. However, systemic insulin-mediated increases in limb blood flow, muscle microvascular perfusion and glucose uptake may be regulated by a central pathway that is NO dependent.

Spontaneous loss of a co-twin and the risk of birth defects after assisted conception.

The study of very early pregnancy loss is impractical in the general population, but possible amongst infertility patients receiving carefully monitored treatments. We examined the association between fetal loss and the risk of birth defects in the surviving co-twin in a retrospective cohort study of infertility patients within an infertility clinic in South Australia from January 1986 to December 2002, linked to population registries for births, terminations and birth defects. The study population consisted of a total of 5683 births. Births from singleton pregnancies without loss were compared with survivors from (1) pregnancies with an empty fetal sac at 6-8 weeks after embryo transfer, (2) fetal loss subsequent to 8-week ultrasound and (3) multiple pregnancy continuing to birth. Odds ratios (OR) for birth defects were calculated with adjustment for confounders. Amongst infertility patients, the prevalence of birth defects was 7.9% for all twin pregnancies without fetal loss compared with 14.6% in pregnancies in which there had been an empty sac at ultrasound, and 11.6% for pregnancies with fetal loss after 6-8 weeks. Compared with singleton pregnancies without loss, the presence of an empty sac was associated with an increased risk of any defect (OR=1.90, 95% confidence intervals (CI)=1.09-3.30) and with multiple defects (OR=2.87, 95% CI=1.31-6.28). Twin pregnancies continuing to birth without loss were not associated with an overall increased prevalence of defects. We conclude that the observed loss of a co-twin by 6-8 weeks of pregnancy is related to the risk of major birth defects in the survivor.

Quantitative general theory for periodic breathing in chronic heart failure and its clinical implications.

BACKGROUND: In patients with chronic heart failure (CHF), periodic breathing (PB) predicts poor prognosis. Clinical studies have identified numerous risk factors for PB (which also includes Cheyne-Stokes respiration). Computer simulations have shown that oscillations can arise from delayed negative feedback. However, no simple general theory quantitatively explains PB and its mechanisms of treatment using widely-understood clinical concepts. Therefore, we introduce a new approach to the quantitative analysis of the dynamic physiology governing cardiorespiratory stability in CHF. METHODS AND RESULTS: An algebraic formula was derived (presented as a simple 2D plot), enabling prediction from easily acquired clinical data to determine whether respiration will be unstable. Clinical validation was performed in 20 patients with CHF (10 with PB and 10 without) and 10 healthy normal subjects. Measurements, including chemoreflex sensitivity (S) and delay (delta), alveolar volume (V(L)), and end-tidal CO(2) fraction (C), were applied to the stability formula. The breathing pattern was correctly predicted in 28 of the 30 subjects. The principal combined parameter (CS)x(delta/V(L)) was higher in patients with PB (14.2+/-3.0) than in those without PB (3.1+/-0.5; P:=0.0005) or in normal controls (2.4+/-0.5; P:=0.0003). This was because of differences in both chemoreflex sensitivity (1749+/-235 versus 620+/-103 and 526+/-104 L/min per atm CO(2); P:=0.0001 and P:<0.0001, respectively) and chemoreflex delay (0.53+/-0.06 vs 0.40+/-0.06 and 0.30+/-0.04 min; P:=NS and P:=0.02). CONCLUSION: This analytical approach identifies the physiological abnormalities that are important in the genesis of PB and explicitly defines the region of predicted instability. The clinical data identify chemoreflex gain and delay time (rather than hyperventilation or hypocapnia) as causes of PB.

Oxygenation in patients with a functionally univentricular circulation and complete mixing of blood: are saturation and flow interchangeable?

BACKGROUND: Perioperative management of patients with complete mixing of pulmonary and systemic blood centers on approximately equating pulmonary (Qp) and systemic (Qs) blood flow (Qp/Qs approximately 1). This empirically derived target is opposed by theoretical studies advocating a target Qp/Qs well below 1. We studied the cause of this persistent discrepancy. METHODS AND RESULTS: Classic theoretical studies have concentrated on maximizing 1 of many potential combination parameters of arterial oxygen content (CaO(2)) and systemic blood flow: total oxygen delivery (DO(2))=CaO(2)xQs. We defined "useful" oxygen delivery as the amount of oxygen above a notional saturation threshold (Sat(Thresh)): D(u)O(2)=carrying capacityx(SaO(2)-Sat(Thresh))xQs. Whereas DO(2) peaks at Qp/Qs ratios <1, D(u)O(2) peaks at higher Qp/Qs ratios, nearer to (or exceeding) 1. Systemic venous saturation (which mirrors tissue oxygen tension) peaks at Qp/Qs=1. CONCLUSIONS: First, the standard model of single-ventricle physiology can be reexpressed in a form allowing analysis by differential calculus, which allows broader conclusions to be drawn than does computer modeling alone. Second, the classic measure DO(2) fails to reflect the fact that proportional changes in saturation and flow are not clinically equivalent. Recognizing this asymmetry by using D(u)O(2) can give a target Qp:Qs balance that better represents clinical experience. Finally, to avoid an arbitrary choice of Sat(Thresh), systemic venous oxygen saturation (SsvO(2)) may be a useful parameter to maximize: this occurs at a Qp/Qs ratio of 1. Attempts to increase DO(2) by altering Qp/Qs away from this value will inevitably reduce SsvO(2) and therefore tissue oxygenation. Oxygen delivery is far from synonymous with tissue oxygen status.

Transplant candidates with severe left ventricular dysfunction managed with medical treatment: characteristics and survival.

OBJECTIVES: This study sought to assess the clinical characteristics and survival of patients with symptomatic heart failure who were referred as potential heart transplant candidates, but were selected for medical management. BACKGROUND: Patients with severe left ventricular dysfunction referred for heart transplantation may be considered too well to be placed immediately on an active waiting transplant list. The clinical characteristics of this patient group and their survival have not been well defined. These patients represent a unique group that are characterized by comparatively low age and freedom from significant comorbid conditions. METHODS: We studied 116 consecutive patients with symptomatic heart failure, severe left ventricular dysfunction (left ventricular ejection fraction 20 +/- 7% [mean +/- SD]) and duration of symptoms >1 month referred for heart transplantation, who were acceptable candidates for the procedure but who were not listed for transplantation because of relative clinical stability. These patients were followed up closely on optimal medical therapy. A variety of baseline clinical, hemodynamic and exercise variables were assessed to define this patient group and used to predict cardiac death and requirement later for heart transplantation. RESULTS: During a mean follow-up period of 25.0 +/- 14.8 months (follow-up 99% complete), there were eight cardiac deaths (7%) (seven sudden, one acute myocardial infarction). Only nine patients (8%) were listed for heart transplantation. Actuarial 1- and 4-year cardiac survival rates were 98 +/- 1% and 84 +/- 7% (mean +/- SE), respectively, and freedom from listing for transplantation was 95 +/- 2% and 84 +/- 7% (mean +/- SE), respectively. Patients were mainly in New York Heart Association functional class II or III and had a preserved cardiac index (2.4 liters/min.m2), pulmonary capillary wedge pressure of 16 +/- 9 mm Hg (mean +/- SD) and maximal oxygen consumption of 17.4 +/- 4.3 ml/min per kg (mean +/- SD). By logistic regression analysis, there was no predictor for cardiac death. Longer duration of heart failure (p = 0.013) and mean pulmonary artery (p < 0.05) and pulmonary systolic (p = 0.014) and diastolic (p < 0.05) pressures correlated significantly with listing for heart transplantation by univariate logistic regression. By multivariate logistic regression, only pulmonary artery systolic pressure (p < 0.004) and duration of heart failure (p < 0.015) remained as predictors for need for later transplantation. CONCLUSIONS: In the current treatment era, prognosis is favorable in a definable group of transplant candidates despite severe left ventricular dysfunction. This patient group can be identified after intensive medical therapy by stable symptoms, a relatively high maximal oxygen uptake at peak exercise and a preserved cardiac output.

Treatment of subdiaphragmatic Hodgkin's disease: is radiotherapy alone appropriate only for inguino-femoral presentations?

PURPOSE: Evaluate the role of staging laparotomy, and the impact of disease subsites on treatment outcome, for sub-diaphragmatic Hodgkin's Disease. METHODS AND MATERIALS: Between 1966 and 1989, 23 patients with Hodgkin's disease limited to sites below the diaphragm were treated at the Royal Adelaide Hospital. The high male:female ratio (2:8), low proportion of nodular sclerosis subtype (26%), and older age (mean = 40) relative to supra-diaphragmatic Hodgkin's disease is consistent with most other series. Thirteen patients underwent staging laparotomy. Initial treatment consisted of radiation therapy alone in 11, chemotherapy alone in 7, and combined modality therapy in 4 patients. This data was then combined with other published series over the last decade, to analyse relapse patterns and treatment results in relation to initial site(s) of disease. RESULTS: The overall, disease specific, and progression free 5 (and 10) year survival rates were 69%, 81%, and 58% respectively. There was no statistically significant effect of staging laparotomy on any of these parameters. Combining these results with those in the literature revealed an unacceptable relapse rate for patients with disease outside of the inguino-femoral region treated with inverted-Y radiation therapy alone. CONCLUSIONS: For the majority of patients with sub-diaphragmatic Hodgkin's disease, staging laparotomy can be avoided. Inverted-Y radiation therapy should only be used for inguino-femoral presentations.

Abnormalities of pulmonary function in patients with congestive heart failure, and reversal with ipratropium bromide.

Patients with congestive heart failure (CHF) have baseline restrictive and obstructive abnormalities in pulmonary function. Thus, improvement of respiratory parameters may provide a new method for the treatment of CHF. Ipratropium is an inhaled anticholinergic bronchodilator with no reported cardiac or systemic effect. A pilot study was performed to investigate the acute effects of a 72 micrograms inhaled dose of ipratropium bromide on pulmonary function and pulmonary artery pressures in 18 nonsmokers and 11 smokers with severe (New York Heart Association class 2 or 3), stable CHF who were referred for orthotopic cardiac transplantation. An unmatched group of 10 healthy subjects (5 men and 5 women, mean age 36.8 +/- 1.8 years) were studied with pulmonary function testing alone. Forced expiratory volume in 1 second (FEV1) in 15 of 18 nonsmokers with CHF showed a favorable response with a mean improvement of 5.1% (2.74 +/- 0.20 to 2.89 +/- 0.19 liter after drug treatment; p = 0.0026). Forced expiratory flow between 25 and 75% of the forced vital capacity (FEF25-75) improved by 19% (2.50 +/- 0.25 to 3.09 +/- 0.28 liter/s; p = 0.0013). Eight of 11 smokers with CHF responded with a 9.5% increase in FEV1 (2.32 +/- 0.21 to 2.54 +/- 0.19 liter; p = 0.0006) and a 23.2% increase in FEF25-75 (1.82 +/- 0.38 to 2.37 +/- 0.46 liter/s; p = 0.0029). Pulmonary artery pressures, cardiac output, systemic arterial pressures, and cardiac rate and rhythm were unaffected by administration of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Trisomy 18/trisomy 13 mosaicism in an adult with profound mental retardation and multiple malformations.

We report on an adult woman with profound mental retardation and multiple anomalies who consists of 3 cell lines: one with trisomy 18, one with trisomy 13, and a normal cell line. Her phenotype includes manifestations of both trisomy syndromes. The origin of these cell lines could have been a doubly aneuploid (48,XX + 13, + 18) or singly aneuploid (47,XX + 18 or 47,XX + 13) zygote with subsequent mitotic nondisjunctions, or a normal zygote with multiple mitotic nondisjunctions. There have been four previous reports of mosaicism involving both trisomy D and trisomy E; all died in the first six months of life. Two of these cases had a doubly aneuploid (48,XX, + D + E) cell line. Our patient illustrates the need for study of several tissues in patients with complex aneuploidy syndromes or atypical manifestations of a given syndrome (such as prolonged survival), as well as the need for caution in counseling families about prognosis for survival in autosomal trisomies which usually are lethal.

Peripheral blood stem cells mobilized from patients with acute myeloid leukaemia have different platelet repopulating abilities compared with those mobilized from patients with other diseases.

Peripheral blood stem cell (PBSC) transplantation gives rapid recovery of neutrophils and platelets and sustained haemopoiesis. However in patients with acute myeloid leukaemia (AML) platelet recovery has a distinctive rapid rise and then secondary fall between 3 to 8 weeks post-transplant. This study compares platelet and neutrophil recovery after PBSC transplantation in 15 patients with AML and 29 patients with other diseases consecutively transplanted in a single unit. PBSC were collected during recovery from consolidation chemotherapy in AML patients and after cyclophosphamide or cytokine administration in the other patient groups. Mononuclear cell numbers collected were similar but CFU-GM numbers were greater from the AML patients. A significant secondary fall occurred only in the platelet count and only in AML patients. Long-term recovery of the platelet count was the same in AML as in the other patients. In AML patients, the fall was the same in the long term remitters as in those who eventually relapsed. Previous studies have not, demonstrated a difference in type of precursors mobilized by differing methods, but have not included AML patients. Megakaryocyte precursors were assayed in this study and showed no consistent differences in number between patient groups however pre-progenitor assays are not yet established especially in the megakaryocytic lineage. The possible explanation for this secondary fall in AML patients is discussed.

Towards a protocol for measurement of maximum spatial peak temporal average acoustic intensity from diagnostic B mode ultrasound scanners in the field.

The Northern Regional Medical Physics Department has been involved in measurement of the acoustic output of diagnostic ultrasound equipment for several years. As the complexity of diagnostic ultrasound equipment has increased, so have the problems of measuring the acoustic outputs of this equipment in the field. Measurements made in the field are often made on unfamiliar pieces of equipment and under tight constraints of time. In these circumstances the magnitude and the conditions under which the true maximum Ispta value occurs may not always be found. The aim of a measurement protocol is therefore to facilitate the measurement of Ispta in the field, so that the measured maximum Ispta value is as close as possible to the 'true maximum' Ispta value. To be of practical benefit the protocol must be succinct and easy to use, as well as applicable to most if not all types of scanner. Our experience has led us to believe that this is possible and that the benefits of a well designed measurement protocol will far outweigh any disadvantages. The development of two measurement protocols is discussed in this paper. The time required to carry out each measurement depends on the number of assumptions made about the operation of the scanner in the protocol used. The first protocol makes very few assumptions about the operation of a scanner; the results from measurements made using this protocol can be used to assess the validity of the much larger number of assumptions made in the second protocol. The results from measurements on three types of scanner using the two protocols are presented. The results demonstrate the validity of most of the assumptions made by the protocols and the potential benefits of using a protocol for measurement of maximum Ispta in the field in terms of reduced measurement time and greater consistency.

True shape and area of proximal isovelocity surface area (PISA) when flow convergence is hemispherical in valvular regurgitation.

The proximal isovelocity surface area (PISA) method for quantifying valvular regurgitation uses an echocardiographic image with superimposed colour Doppler mapping to visualise the contours of velocity in the blood travelling towards the regurgitant orifice. The flux of blood through the regurgitant orifice is obtained as the product of the area of one of these (presumed hemispherical) contours and the speed of the blood passing through it. However, colour Doppler mapping measures the velocity component towards the echo probe (v cos theta;) rather than speed (v), so that the contours of equal Doppler velocity (isodoppler velocity contours) differ from isospeed contours. We derive the shape of the isodoppler contour surface obtainable by colour Doppler mapping, and show that its area is much less than that of the hemispherical isospeed contour. When regurgitant flux is derived from an appropriate single measure of contour dimension, an appropriate result may be obtained. However, if the true echocardiographic surface area is measured directly, the regurgitant flux will be substantially underestimated. Indeed, the conditions necessary for isodoppler velocity contours to be hemispherical are extraordinary. We should not therefore make deductions from the apparent shape for the convergence zone without considering the principles by which the image is generated. The discrepancy will assume practical significance when increased resolution of colour Doppler technology makes measurement of apparent surface area feasible. Assuming the flow contours are indeed hemispherical, a 'correction' factor of 1.45 would be required.

Quantitative sonography of muscle.

Ultrasound imaging allows detection of pathologic change in muscle on the basis of increased strength of echoes. With current commercial equipment, however, there is no method of quantitation of the echoes representing muscle, and there is lack of uniformity in scanning methodology. We describe a specially constructed scanning system, designed to access the raw echo data directly from the ultrasound transducer, and allow display and measurement of the echo signals on a computer. In a study of 38 boys with Duchenne muscular dystrophy, aged 1 to 11 years, who had an ultrasound scan of the thigh muscle, 32 (84%) had abnormality on quantitation of the ultrasound echoes. The quantitative techniques we describe could easily be incorporated into the design of ultrasound scanners.

A survey of the acoustic outputs of diagnostic ultrasound equipment in current clinical use.

Surveys published up to 1991 have highlighted a steady increase in the acoustic outputs from diagnostic ultrasound equipment. Since 1991 we have made measurements of the maximum peak negative pressure (p-) and spatial peak temporal average intensity (ISPTA) produced by 223 probes from 82 scanning systems in current clinical use in the Northern Region in the UK. Measurements have also been made of the maximum total acoustic power generated by 45 probes from 17 scanners. The results from these measurements are presented in this article and compared to the results of a similar survey of equipment from both the Northern and Wessex Regions in the UK and published in 1991. The comparison shows that measured ISPTA values have increased approximately sixfold in B mode and approximately threefold in colour Doppler mode. Also, measured total acoustic power values have doubled in pulsed Doppler mode. The present survey also draws attention to some particularly high ISPTA values obtained from a number of probes and scanning systems. This survey has shown that measurements of acoustic outputs from diagnostic ultrasound scanners in current clinical use are substantially higher than reported in earlier surveys and, for certain scanners, the acoustic outputs from scanned beam modes of operation can reach levels hitherto only found in pulsed Doppler mode.

A combined ultrasonic linear array scanner and pulsed Doppler velocimeter for the estimation of blood flow in the foetus and adult abdomen--II: Clinical evaluation.

A combined pulsed Doppler and linear array scanner is used to measure volume blood flow in 75 aortas and 45 umbilical veins of foetuses in the 3rd trimester. The mean aortic flow was 277 ml/min/kg and the mean umbilical venous flow was 122 ml/min/kg. Mean flow in the portal veins of normal subjects was found to be between 0.6 and 2.0 l/min. Clear signals were obtained from the adult kidney but no volume flow calculation has yet been attempted. The use of a spectrum analyser is considered fundamental to the accurate interpretation and processing of the Doppler signals. Medical and electronic artefacts are described which would not be detected without the use of an analyser.

A combined ultrasonic linear array scanner and pulsed Doppler velocimeter for the estimation of blood flow in the foetus and adult abdomen--I: Technical aspects.

A method is proposed for estimating the volume blood flow of deep lying vessels in the foetus and in adult portal vein and renal vessels. The equipment combines a 3.5 MHz linear array scanner with a 2 or 4 MHz pulsed Doppler. The pulsed Doppler tranducer is connected to the linear array by two movable arms. A real time spectrum analyser is used to process the Doppler signals. A water bath was used to perform an in vitro calibration of the complete system and to adjust the registration of the Doppler sample volume with the echo picture. Several possible inaccuracies in vessel diameter measurement are discussed and the mean of several caliper measurements described by Eik-Ness (1982) is used. Time Motion is thought to be the better method but is more complicated in practice.

Characterizing the microscopic physics near moving contact lines using dynamic contact angle data.

Directly probing the fluid flow and liquid-vapor interface shape in the microscopic immediate vicinity of the moving contact line can only be accomplished in very specific and isolated cases. Yet this physics is critical to macroscopic dynamic wetting. Here we examine the microscopic (or inner) physics of spreading silicone fluids using data of macroscopic dynamic contact angle versus Capillary number Ca=U mu/sigma. This dynamic contact angle is precisely defined so that it can be related back to the microscopic behavior through detailed theory. Our results indicate that the parameters describing the inner region have a detectable dependence on spreading velocity when this velocity exceeds a critical value. This dependence is not scaled (i.e., the data are not collapsed) by Ca, which suggests that an additional time scale must be present in the model of the inner region.

Relating physical activity to health status, social connections and community facilities.

An important public health goal is to increase the population's participation in regular, moderate physical activity. Descriptive epidemiological studies that focus only on associations between physical activity and demographic and psychological factors are not sufficient to inform exercise promotion strategies, and a broader view of health is required. This study investigates the additional factors of health status, social connections and satisfaction with local area facilities by analysing data from a 1987 community health survey of 1765 residents of Adelaide. Factors associated with low activity were age group, education, general health (women), reduced mobility, number of social connections (men) and degree of satisfaction with recreation facilities. Including social and structural factors is valuable for research into interventions, policy and theory relating to physical activity as it brings theoretical perspectives and links to other areas of public health and social research.

Strontium-90 as an indicator of time since death: a pilot investigation.

The results of a pilot investigation are presented. The study aimed to show that the presence of radioactive strontium-90 in human bone could be used as evidence of active uptake during life. In this way the time since death of the individual could be identified as occurring before or after the date when atmospheric levels of radioactive strontium were at a peak in the early 1960s. The results of this initial investigation were encouraging but further detailed analysis is required on a substantially larger sample of material spanning a more controlled time period.