Outcomes associated with planned place of birth among women with low-risk pregnancies

Background:Previous studies have shown that planned home birth is associated with a decreased likelihood of intrapartum intervention with no difference in neonatal outcomes compared with planned hospital birth. The purpose of our study was to evaluate different birth settings by comparing neonatal mortality, morbidity and rates of birth interventions between planned home and planned hospital births in Ontario, Canada.Methods:We used a provincial database of all midwifery-booked pregnancies between 2006 and 2009 to compare women who planned home birth at the onset of labour to a matched cohort of women with low-risk pregnancies who had planned hospital births attended by midwives. We conducted subgroup analyses by parity. Our primary outcome was stillbirth, neonatal death (< 28 d) or serious morbidity (Apgar score < 4 at 5 min or resuscitation with positive pressure ventilation and cardiac compressions).Results:We compared 11 493 planned home births and 11 493 planned hospital births. The risk of our primary outcome did not differ significantly by planned place of birth (relative risk [RR] 1.03, 95% confidence interval [CI] 0.68–1.55). These findings held true for both nulliparous (RR 1.04, 95% CI 0.62–1.73) and multiparous women (RR 1.00, 95% CI 0.49–2.05). All intrapartum interventions were lower among planned home births.Interpretation:Compared with planned hospital birth, planned home birth attended by midwives in a jurisdiction where home birth is well-integrated into the health care system was not associated with a difference in serious adverse neonatal outcomes but was associated with fewer intrapartum interventions.In Ontario, Canada, the College of Midwives of Ontario has regulated midwifery since 1994, and increasing numbers of women with low obstetrical risk and their newborns receive care in a publicly funded, midwifery-led continuity of care model.¹ Midwives have admission and discharge privileges at their local hospitals and are able to consult or transfer care to other health care providers if required. In Ontario, midwives attend a small proportion of all births in the province (10%), and about 20% of the births they attend take place at home.² A comprehensive record is maintained for every woman and infant in a midwife’s care. Until 2009, this record was submitted to the provincial Ministry of Health and Long-term Care (MOHLTC) through the Ontario Midwifery Program to access reimbursement for care provided.In the last century, Western culture has come to view hospital birth as safer than home birth.³ Recently, however, the value of hospital birth for all women with low-risk pregnancies has come into question; it has been suggested that in the absence of benefit, a planned hospital birth for this population may increase the use of intrapartum interventions, including cesarean delivery.^4–7 Even though recent studies comparing planned home and hospital births have had moderate sample sizes, they are individually limited in their ability to report definitively on rare outcomes such as death. Owing to a lack of evidence from randomized controlled trials (RCTs) to show that restricting a woman’s freedom to choose a place of birth prevents harm, the authors of a 2012 Cochrane review of planned hospital versus planned home births concluded that home birth services with collaborative medical backup should be established and offered to women with low-risk pregnancies in all jurisdictions.⁸ This conclusion, along with findings from the large English Birthplace Cohort Study,⁴ may be what prompted the National Institute for Health and Care Excellence (NICE) in England to update its intrapartum care guidelines to recommend that, for women at low risk of birth-associated complications, home birth should be considered a generally safe option.⁹ With the paucity of information derived from RCTs,⁸ observational studies are essential to continue to inform and monitor maternal and infant outcomes for women at low obstetrical risk who plan home or hospital birth, and to continue to provide pregnant women with quality information about choice of birthplace.The primary purpose of this retrospective cohort study was to determine the risk of stillbirth or neonatal death or serious neonatal morbidity among women at low obstetrical risk whose deliveries were attended by midwives and who had planned a home birth at the onset of labour, compared with women at low obstetrical risk who planned a hospital birth at the onset of labour. In addition, we also compared the incidence of maternal death and morbidity, birth interventions and breastfeeding between planned home births and planned hospital births.     

Does perspective matter? A case study comparing Eulerian and Lagrangian estimates of common murre (Uria aalge) distributions

Studies estimating species' distributions require information about animal locations in space and time. Location data can be collected using surveys within a predetermined frame of reference (i.e., Eulerian sampling) or from animal‐borne tracking devices (i.e., Lagrangian sampling). Integration of observations obtained from Eulerian and Lagrangian perspectives can provide insights into animal movement and habitat use. However, contemporaneous data from both perspectives are rarely available, making examination of biases associated with each sampling approach difficult. We compared distributions of a mobile seabird observed concurrently from ship, aerial, and satellite tag surveys during May, June, and July 2012 in the northern California Current. We calculated utilization distributions to quantify and compare variability in common murre (Uria aalge) space use and examine how sampling perspective and platform influence observed patterns. Spatial distributions of murres were similar in May, regardless of sampling perspective. Greatest densities occurred in coastal waters off southern Washington and northern Oregon, near large murre colonies and the mouth of the Columbia River. Density distributions of murres estimated from ship and aerial surveys in June and July were similar to those observed in May, whereas distributions of satellite‐tagged murres in June and July indicated northward movement into British Columbia, Canada, resulting in different patterns observed from Eulerian and Lagrangian perspectives. These results suggest that the population of murres observed in the northern California Current during spring and summer includes relatively stationary individuals attending breeding colonies and nonstationary, vagile adults and subadults. Given the expected growth of telemetry studies and advances in survey technology (e.g., unmanned aerial systems), these results highlight the importance of considering methodological approaches, spatial extent, and synopticity of distribution data sets prior to integrating data from different sampling perspectives.     

Rapid shifts in the thermal sensitivity of growth but not development rate causes temperature–size response variability during ontogeny in arthropods

Size at maturity in ectotherms commonly declines with warming. This near‐universal phenomenon, formalised as the temperature–size rule, has been observed in over 80% of tested species, from bacteria to fish. The proximate cause has been attributed to the greater temperature dependence of development rate than growth rate, causing individuals to develop earlier but mature smaller in the warm. However, few studies have examined the ontogenetic progression of the temperature–size response at high resolution. Using marine planktonic copepods, we experimentally determined the progression of the temperature–size response over ontogeny. Temperature–size responses were not generated gradually from egg to adult, contrary to the predictions of a naïve model in which development rate was assumed to be more temperature‐dependent than growth rate, and the difference in the temperature dependence of these two rates remained constant over ontogeny. Instead, the ontogenetic progression of the temperature–size response in experimental animals was highly episodic, indicating rapid changes in the extent to which growth and development rates are thermally decoupled. The strongest temperature–size responses occurred temporally mid‐way through ontogeny, corresponding with the point at which individuals reached between ~5 and 25% of their adult mass. Using the copepod Oithona nana, we show that the temperature‐dependence of growth rate varied substantially throughout ontogeny, whereas the temperature dependence of development rate remained constant. The temperature‐dependence of growth rate even exceeded that of development rate in some life stages, leading to a weakening of the temperature–size response. Our analyses of arthropod temperature–size responses from the literature, including crustaceans and insects, support these conclusions more broadly. Overall, our findings provide a better understanding of how the temperature–size rule is produced over ontogeny. Whereas we find support for the generality of developmental rate isomorphy in arthropods (shared temperature dependence of development rate across life stages), this concept appears not to apply to growth rates.     

The influence of subjective sleep quality on the association between eveningness and depressive symptoms

Increasing evidence suggests that eveningness is associated with increased risk for depression. Eveningness, however, is also associated with poor sleep quality and the unique role of eveningness in depressive symptomatology remains to be elucidated. The goal of the current study, therefore, was to examine the inter-relationships between eveningness, subjective sleep quality and depressive symptoms in healthy participants free of current or previous depression and sleep disorder. Here, 167 healthy participants (mean age 24.16, 129/38 females/males) completed the reduced Morningness–Eveningness Questionnaire (rMEQ), the Pittsburgh Sleep Quality Index (PSQI) and the Centre for Epidemiological Studies Depression Scale (CES-D). Bootstrap mediation analysis for a simple mediation model including rMEQ, PSQI and CES-D was applied. Eveningness was associated with increased depressive symptoms and mediation analysis showed that this relationship was partly mediated by sleep quality. Our results suggest that indicators of depression observed in evening-type individuals cannot be attributed exclusively to disturbed sleep. We suggest that interventions that target both sleep quality and dysfunctional cognitive styles would be optimal to promote well-being in evening-type individuals.     

Cost-Effectiveness of Coronary Artery Calcium Testing for Coronary Heart and Cardiovascular Disease Risk Prediction to Guide Statin Allocation: The Multi-Ethnic Study of Atherosclerosis (MESA)

Background

The Multi-Ethnic Study of Atherosclerosis (MESA) showed that the addition of coronary artery calcium (CAC) to traditional risk factors improves risk classification, particularly in intermediate risk asymptomatic patients with LDL cholesterol levels <160 mg/dL. However, the cost-effectiveness of incorporating CAC into treatment decision rules has yet to be clearly delineated.

Objective

To model the cost-effectiveness of CAC for cardiovascular risk stratification in asymptomatic, intermediate risk patients not taking a statin. Treatment based on CAC was compared to (1) treatment of all intermediate-risk patients, and (2) treatment on the basis of United States guidelines.

Methods

We developed a Markov model of first coronary heart disease (CHD) and cardiovascular disease (CVD) events. We modeled statin treatment in intermediate risk patients with CAC≥1 and CAC≥100, with different intensities of statins based on the CAC score. We compared these CAC-based treatment strategies to a “treat all” strategy and to treatment according to the Adult Treatment Panel III (ATP III) guidelines. Clinical and economic outcomes were modeled over both five- and ten-year time horizons. Outcomes consisted of CHD and CVD events and Quality-Adjusted Life Years (QALYs). Sensitivity analyses considered the effect of higher event rates, different CAC and statin costs, indirect costs, and re-scanning patients with incidentalomas.

Results

We project that it is both cost-saving and more effective to scan intermediate-risk patients for CAC and to treat those with CAC≥1, compared to treatment based on established risk-assessment guidelines. Treating patients with CAC≥100 is also preferred to existing guidelines when we account for statin side effects and the disutility of statin use.

Conclusion

Compared to the alternatives we assessed, CAC testing is both effective and cost saving as a risk-stratification tool, particularly if there are adverse effects of long-term statin use. CAC may enable providers to better tailor preventive therapy to patients'' risks of CVD.     

Ostracods and the Holocene palaeolimnology of Lake Qarun, with special reference to past human–environment interactions in the Faiyum (Egypt)

We present an ostracod record covering the past two millennia from an 8.25-m core taken from Lake Qarun, in the Faiyum Depression of Egypt. The occurrence of ostracod species in the lake is controlled primarily by variations in solute composition, which are in turn related to shifts in catchment land use. At times when the Faiyum Depression supported thriving agriculture, lake water contained Na⁺–Cl^? brine, and Cyprideis torosa dominated the ostracod assemblage. When the Faiyum Depression experienced periods of environmental and economic decline, lake water contained Na⁺–HCO₃ ^? brine, and Limnocythere inopinata dominated. The relative abundance of other ostracod species provides additional information about past conditions in Lake Qarun including salinity and lake level changes. Overall, the ostracod assemblages provide evidence for human influences in the Faiyum, which extend back before instrumental or detailed observational records began.     

Effects of competition and season on survival and maturation of young bank vole females

In territorial microtines intra-specific density dependent processes can limit the maturation of individuals during the summer of their birth. This may have demographic consequences by affecting the number and the age distribution of breeding individuals in the population. Little is known about this process on a community level, though populations of many northern microtine species fluctuate in synchrony and are known to interfere socially with each other. We experimentally studied the influence of the field vole Microtus agrestis on maturation, breeding, space use and survival of weanling bank voles, Clethrionomys glareolus. Two additive competition experiments on bank vole populations were conducted in large outdoor enclosures, half of them additionally housing a field vole population. In a mid-summer experiment low population density and absence of older breeding females minimised intra-specific competition. Survival was not affected by the presence of field voles. Season had a significant effect on both the probability of maturation and breeding of the weanlings. Competition with field voles significantly delayed breeding, and coupled with seasonal effects decreased the probability of breeding. In a late-summer experiment breeding and survival of bank vole weanlings were studied for three weeks as part of a high density breeding bank vole population. Weanlings did not mature at all nor were their space use and survival affected by the presence of field voles. Our results show that competition with other species can also have an impact on breeding of immatures. In an extreme seasonal environment, even a short delay of breeding may decrease survival chances of offspring. Seasonal and competition effects together may thus limit the contribution of year born females to reproductive output of the population. Other studies have shown that adult breeding bank voles suffer lower survival in the presence of field voles, but this study showed no survival effects on the weanlings. Thus it might be beneficial for weanlings to stay immature especially in the end of the breeding season and postpone reproduction to the next breeding season if densities of competing species are high.     

Physiological Studies of Oxygen Protection Mechanisms in the Heterocysts of Anabaena cylindrica

The mechanism of O₂ protection of nitrogenase in the heterocysts of Anabaena cylindrica was studied in vivo. Resistance to O₂ inhibition of nitrogenase activity correlated with the O₂ tension of the medium in which heterocyst formation was induced. O₂ resistance also correlated with the apparent K_m for acetylene, indicating that O₂ tension may influence the development of a gas diffusion barrier in the heterocysts. The role of respiratory activity in protecting nitrogenase from O₂ that diffuses into the heterocyst was studied using inhibitors of carbon metabolism. Reductant limitation induced by 3-(3,4-dichlorophenyl)-1, 1-dimethylurea increased the O₂ sensitivity of in vivo acetylene reduction. Azide, at concentrations (30 mM) sufficient to completely inhibit dark nitrogenase activity (a process dependent on oxidative phosphorylation for its ATP supply), severely inhibited short-term light-dependent acetylene reduction in the presence of O₂ but not in its absence. After 3 h of aerobic incubation in the presence of 20 mM azide, 75% of cross-reactive component I (Fe-Mo protein) in nitrogenase was lost; less than 35% was lost under microaerophilic conditions. Sodium malonate and monofluoroacetate, inhibitors of Krebs cycle activity, had only small inhibitory effects on nitrogenase activity in the light and on cross-reactive material. The results suggest that oxygen protection is dependent on both an O₂ diffusion barrier and active respiration by the heterocyst.     

H－ras在颊粘膜正常、良性、癌前及恶性变上皮中的表达：免疫组织化学定量研究

本文通过建立图象分析方法对免疫组织化学反应结果进行定量,检测观察Ｈ－ｒａｓ在口腔颊粘膜上皮在正常（Ｎ）、慢性炎症（ＩＦ）、癌旁上皮（ＥＡＣ）和鳞癌（ＳＣＣ）的变化过程中的表达并进行分析。结果显示Ｈ－ｒａｓ在ＳＣＣ组中,以中等分化的ＳＣＣ无论是Ｈ－ｒａｓ表达的量还是细胞阳性率都较高。此外,组织学观察显示,Ｈ－ｒａｓ在处于分化末期但尚未角化的正常上皮细胞中有较高的表达。本文结果显示了Ｈ－ｒａｓ的过表达与上皮细胞的会化程度密切相关。本研究还显示,所采用的阳性区域透光值、平均总透光值及阳性反应区域与阴性反应区域比值可靠并有相关性。这进一步说明了用免疫组化定量方法检测Ｈ－ｒａｓ癌基因表达的精确和可靠性。