Role stress,physical symptomatology,and turnover intentions: A causal analysis of three alternative specifications

Causal relationships involving role stressors, physical symptomatology, and turnover intentions were examined within three alternative specifications. These specifications stemmed from Beehr and Newman's (1978) and Schuler's (1982) models of role stress and Locke's (1976) theory of job satisfaction. The results, derived from LISREL VI analyses, indicate that a revised Schuler model is the most plausible specification. Findings are discussed in terms of implications for understanding role stress and employee withdrawal.     

Between pregnancy biological variability of first trimester markers of Down syndrome: implications for screening in subsequent pregnancies

In a group of 149 women who had undergone routine first trimester screening using fetal nuchal translucency thickness (NT) and maternal serum free β-hCG and pregnancy associated plasma protein-A (PAPP-A) in two consecutive pregnancies the within person between pregnancy biological variability of these markers has been assessed. For fetal NT there was no correlation between NT MoM in the first and second pregnancy (r=0.0800). For maternal serum free β-hCG MoM a significant correlation was observed (r=0.4174) as was also found for PAPP-A MoM (r=0.3270). The implications for such between pregnancy marker association is that women who have an increased risk of Down syndrome in their first pregnancy are 1.5–2 times more likely to repeat this event in their next pregnancy. This observation may be useful in counselling women in the first trimester screening of a subsequent pregnancy. Copyright © 2001 John Wiley & Sons, Ltd.     

Apparent relationships between anthropogenic factors and climate change indicators and POPs deposition in a lacustrine system

Climate change and anthropogenic activities are expected to impact the environmental behaviors and fates of persistent organic pollutants(POPs), however, quantitative studies on these combined factors are scarce. In this study, dichlorodiphenyltrichloroethane(DDTs), polycyclic aromatic hydrocarbons(PAHs), and polychlorinated biphenyls(PCBs)were used as examples to identify how and when those factors may be related to the deposition of POPs in the sediment of Lake Chaohu, China, using generalized additive models(GAMs). Three historical trends of DDT, PAH, and PCB deposition were delineated in a dated sediment core encompassing ～100 years of historical record: a steady state or gradually increasing stage, a rapidly increasing stage, and a declining stage. The GAM results showed that aquatic total phosphorus(TP) concentrations and regional GDP(anthropogenic factors) were dominant contributors to POP accumulation rates in the lake sediment. The fitted relationships between air temperature and sedimentary DDT and PAH concentrations were linear and negative, while a positive linear relationship was found for PCBs, suggesting that Lake Chaohu may have become a net source for DDTs and PAHs, and a sink for PCBs, under a progressively warming climate.     

First trimester maternal serum placenta growth factor (PIGF)concentrations in pregnancies with fetal trisomy 21 or trisomy 18

Placenta growth factor (PIGF), an angiogenic factor belonging to the vascular endothelial growth factor family, pregnancy-associated plasma protein A (PAPP-A) and free β-human chorionic gonadotrophin (β-hCG) were measured in maternal serum from 45 pregnancies with trisomy 21, 45 with trisomy 18 and 493 normal controls at 10–13 completed weeks of gestation. In the normal pregnancies maternal serum PIGF levels increased exponentially with gestation. The median multiple of the median (MoM) PIGF concentration in the trisomy 21 group (1.26 MoM) was significantly higher (p<0.0001) than in the control group (1.00 MoM). In the trisomy 18 group the median PIGF was lower (0.889 MoM) but this did not quite reach significance (p=0.064). The corresponding median MoM values for PAPP-A were 1.00 MoM for the controls, 0.49 MoM for trisomy 21 and 0.16 MoM for trisomy 18. The median MoM values for free β-hCG were 1.00 MoM for the controls, 2.05 MoM for trisomy 21 and 0.38 MoM for trisomy 18. In the control group there was a small but significant correlation of PIGF with free β-hCG (r=+0.1024) and PAPP-A (r=+0.2288). In the trisomy 18 group there was a significant association between PIGF and free β-hCG (r=+0.2629) but not with PAPP-A (r=+0.0038). In the trisomy 21 group there was a small but significant association with PAPP-A (r=+0.1028) but not with free β-hCG (r=+0.0339). The separation of affected and unaffected pregnancies in maternal serum PIGF is small, and therefore it is unlikely that measurement of PIGF would improve screening for these abnormalities provided by the combination of fetal nuchal translucency and maternal serum PAPP-A and free β-hCG. Copyright © 2001 John Wiley & Sons, Ltd.     

The legal frameworks that govern fetal surgery in the United Kingdom,European Union,and the United States

The specialty of fetal surgery or fetal intervention is one of the most exciting emerging fields of modern medicine. It is made possible by decades of major developments in antenatal imaging, obstetric anaesthesia, fetal medicine, paediatric surgery, and of course by the bold and novel practitioners willing to take new steps to advance the field. Beginning in the 1970s, it has now reached a stage of maturity where there are several established in utero procedures and countless clinical trials and studies to develop more. But what is the legal situation that fetal surgeons find themselves in? What are the rights and legal protections for the fetus and the mother, both of which are arguably the patient? This article will address this question, discussing and summarising the current legal frameworks governing fetal surgery in the jurisdictions of the United Kingdom, European Court of Human Rights, and the United States of America as well as discuss what the future may hold and how researchers and physicians in the specialty can best navigate the legal environment.