Virtual reality learning: A randomized controlled trial assessing medical student knowledge of fetal development.

OBJECTIVE: To investigate whether a virtual reality learning environment (VRLE) enhanced student understanding and knowledge compared with a traditional tutorial. METHOD: A randomized controlled trial involving medical students from University College Dublin, Ireland. Participants were assigned to an intervention (VRLE involving a 15-min learning experience on the stages of fetal development) or control (PowerPoint tutorial on the same topic) group. Multiple choice questionnaires (MCQs) assessed knowledge at three time points: preintervention, immediately postintervention, and 1 week postintervention. Primary outcomes were differences in MCQ knowledge scores postintervention between groups. Secondary outcomes included attitudes on the learning experience assessed using the Student Satisfaction and Self-Confidence in Learning Scale (SCLS) and the Virtual Reality Design Scale (VRDS). RESULTS: No statistically significant between-group differences were found in the primary outcome assessing postintervention knowledge scores. Within-group differences in knowledge scores were significant among the three time points for both the intervention (P < 0.01 [95% confidence interval, 5.33-6.19]) and control (P = 0.02 [95% confidence interval, 5.74-6.49]) groups. Mean levels of satisfaction and self-confidence in learning were higher in the intervention group compared with the control group: 54.2 (standard deviation, 7.5) and 50.5 (standard deviation, 7.2), respectively (P = 0.21). CONCLUSION: VRLEs are a learning tool that can support knowledge development.

Towards an explainable clinical decision support system for large-for-gestational-age births.

A myriad of maternal and neonatal complications can result from delivery of a large-for-gestational-age (LGA) infant. LGA birth rates have increased in many countries since the late 20th century, partially due to a rise in maternal body mass index, which is associated with LGA risk. The objective of the current study was to develop LGA prediction models for women with overweight and obesity for the purpose of clinical decision support in a clinical setting. Maternal characteristics, serum biomarkers and fetal anatomy scan measurements for 465 pregnant women with overweight and obesity before and at approximately 21 weeks gestation were obtained from the PEARS (Pregnancy Exercise and Nutrition with smart phone application support) study data. Random forest, support vector machine, adaptive boosting and extreme gradient boosting algorithms were applied with synthetic minority over-sampling technique to develop probabilistic prediction models. Two models were developed for use in different settings: a clinical setting for white women (AUC-ROC of 0.75); and a clinical setting for women of all ethnicity and regions (AUC-ROC of 0.57). Maternal age, mid upper arm circumference, white cell count at the first antenatal visit, fetal biometry and gestational age at fetal anatomy scan were found to be important predictors of LGA. Pobal HP deprivation index and fetal biometry centiles, which are population-specific, are also important. Moreover, we explained our models with Local Interpretable Model-agnostic Explanations (LIME) to improve explainability, which was proven effective by case studies. Our explainable models can effectively predict the probability of an LGA birth for women with overweight and obesity, and are anticipated to be useful to support clinical decision-making and for the development of early pregnancy intervention strategies to reduce pregnancy complications related to LGA.

Does exercise therapy improve pulmonary function in patients with Adolescent Idiopathic Scoliosis?

INTRODUCTION: Exercise therapy is frequently used for treating patients with Adolescent Idiopathic Scoliosis (AIS) however no previous review has evaluated the effect of exercise therapy on pulmonary function in this population. OBJECTIVE: To systematically analyze the literature on the effect of exercise therapy on pulmonary function in patients with AIS. METHODS: A systematic electronic database search (CINAHL, Embase, Medline, Web of Science) was conducted. Manual searches of key reviews and studies were also conducted. Studies that included exercise-based interventions to improve pulmonary function in patients with AIS and reported pre- and post-intervention pulmonary function test scores were included. Test scores were compared using standardized mean difference (SMD) between intervention and control groups in randomized control trials (RCT) and mean ± SD between pre- and post-intervention in prospective intervention studies (PI). Methodological quality was assessed using a modified Downs and Black checklist. RESULTS: Fifteen studies met the inclusion criteria (six RCTs and nine PIs). Results indicated the positive effect of exercise-based therapy on lung volumes (FVC/VC) and FEV1 in patients with AIS. CONCLUSION: Exercise therapy has a positive effect on lung volumes in patients with AIS. The quality of many studies was only 'fair,' therefore more suitably powered higher level clinical trials are required.

Virtual reality in midwifery education: A mixed methods study to assess learning and understanding.

BACKGROUND: Virtual reality learning environments (VRLEs) are a potentially valuable learning tool that have recently increased in popularity due to widespread availability and decreased cost. VRLEs can provide an immersive learning environment that increases the understanding of three-dimensional relationships between anatomical structures. However, there is a paucity of evidence in the literature supporting its use within Midwifery education. OBJECTIVES: To explore the effectiveness of a VRLE as an educational tool in midwifery education. SETTING: A large University in Ireland, with institutional ethical approval. PARTICIPANTS: Undergraduate and graduate degree midwifery students. DESIGN: A descriptive qualitative and quantitative study was carried out. Data collection was carried out between September 2020 and March 2021. METHODS: Participants underwent a VRLE lesson based on the topic of fetal lie, position, and presentation in pregnancy. A multiple-choice questionnaire was used to quantitatively evaluate knowledge before and immediately after the intervention, and knowledge retention after one week. Qualitative data was collected using open-ended questions in the questionnaire. The primary outcome was a difference in pre- and post-intervention knowledge scores. Data was analysed using repeated measures one-way ANOVA. Qualitative data was analysed using thematic analysis and simple content analysis. All students participated in the quantitative and qualitative components of the study. Secondary outcomes included participant satisfaction and self-confidence in learning which were analysed using thematic analysis. The side effect profile of the virtual reality device was also explored using open-ended questions in the questionnaire. RESULTS: Forty-one midwifery students participated in the study, with a 100 % participation and response rate. Repeated measures one-way ANOVA revealed no statistically significant differences in knowledge scores pre- and post-intervention. Participants rated high satisfaction and self-confidence scores with regard to the VRLE as a learning modality. Side effects most commonly experienced by participants included dizziness (49 %), disorientation (30 %) and symptoms similar to motion sickness (32 %). The following themes were identified: "Learning in 3D", "The Power of Visual Learning", "The value of Educational Technology", "Learning can be fun and enjoyable". CONCLUSIONS: This study showed that the VRLE had no impact on knowledge gain, though high levels of satisfaction and self-confidence indicate a positive response to the VRLE. VRLEs are a potentially valuable learning tool to help enhance the student learning experience, promoting increased engagement, satisfaction, and self-confidence with the learning material.

Diet and mental health in pregnancy: Nutrients of importance based on large observational cohort data.

OBJECTIVE: To determine associations between dietary intake and well-being in pregnancy. METHODS: This retrospective cohort analysis combined three studies: the ROLO Study (a randomized controlled trial of a low-glycemic-index diet in pregnancy), the Pregnancy Exercise and nutrition Research Study with smartphone application support (PEARS), and a randomized controlled trial on probiotics. All data were collected before study interventions (16 wk). Dietary intakes during pregnancy were determined using 3-day food diaries. The five-item World Health Organization Well-Being Index was used to assess mental well-being. Initial associations were evaluated using Pearson correlations and further defined with multiple regression analysis adjusted for age, body mass index (BMI), Pobal Haase and Pratschke deprivation index, and metabolic equivalent of task minutes scores. RESULTS: A total of 1521 women were included in the analysis (mean age, 32+4 y; mean BMI, 27 kg/m2 [IQR, 17-56 kg/m2]). The mean well-being score was 59%. Regression analysis showed that fiber (B = 0.07; P = 0.02), magnesium (B = 0.08; P < 0.01), niacin (B = 0.09; P < 0.01), thiamine (B = 0.07; P = 0.01), and folate (B = 0.08; P = 0.02) were all positively and significantly associated with well-being in a pregnant population. The Benjamini-Hochberg procedure to correct for multiple testing was applied, and significance remained. CONCLUSIONS: Maternal nutrition and well-being are related during early pregnancy. Our findings suggest that fiber, magnesium, and particular B vitamins may be of importance for promoting positive mental well-being during pregnancy.

Learning Outcomes of Immersive Technologies in Health Care Student Education: Systematic Review of the Literature.

BACKGROUND: There is a lack of evidence in the literature regarding the learning outcomes of immersive technologies as educational tools for teaching university-level health care students. OBJECTIVE: The aim of this review is to assess the learning outcomes of immersive technologies compared with traditional learning modalities with regard to knowledge and the participants' learning experience in medical, midwifery, and nursing preclinical university education. METHODS: A systematic review was conducted according to the Cochrane Collaboration guidelines. Randomized controlled trials comparing traditional learning methods with virtual, augmented, or mixed reality for the education of medicine, nursing, or midwifery students were evaluated. The identified studies were screened by 2 authors independently. Disagreements were discussed with a third reviewer. The quality of evidence was assessed using the Medical Education Research Study Quality Instrument (MERSQI). The review protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews) in April 2020. RESULTS: Of 15,627 studies, 29 (0.19%) randomized controlled trials (N=2722 students) were included and evaluated using the MERSQI tool. Knowledge gain was found to be equal when immersive technologies were compared with traditional learning modalities; however, the learning experience increased with immersive technologies. The mean MERSQI score was 12.64 (SD 1.6), the median was 12.50, and the mode was 13.50. Immersive technology was predominantly used to teach clinical skills (15/29, 52%), and virtual reality (22/29, 76%) was the most commonly used form of immersive technology. Knowledge was the primary outcome in 97% (28/29) of studies. Approximately 66% (19/29) of studies used validated instruments and scales to assess secondary learning outcomes, including satisfaction, self-efficacy, engagement, and perceptions of the learning experience. Of the 29 studies, 19 (66%) included medical students (1706/2722, 62.67%), 8 (28%) included nursing students (727/2722, 26.71%), and 2 (7%) included both medical and nursing students (289/2722, 10.62%). There were no studies involving midwifery students. The studies were based on the following disciplines: anatomy, basic clinical skills and history-taking skills, neurology, respiratory medicine, acute medicine, dermatology, communication skills, internal medicine, and emergency medicine. CONCLUSIONS: Virtual, augmented, and mixed reality play an important role in the education of preclinical medical and nursing university students. When compared with traditional educational modalities, the learning gain is equal with immersive technologies. Learning outcomes such as student satisfaction, self-efficacy, and engagement all increase with the use of immersive technology, suggesting that it is an optimal tool for education.

An explainable machine learning-based clinical decision support system for prediction of gestational diabetes mellitus.

Gestational Diabetes Mellitus (GDM), a common pregnancy complication associated with many maternal and neonatal consequences, is increased in mothers with overweight and obesity. Interventions initiated early in pregnancy can reduce the rate of GDM in these women, however, untargeted interventions can be costly and time-consuming. We have developed an explainable machine learning-based clinical decision support system (CDSS) to identify at-risk women in need of targeted pregnancy intervention. Maternal characteristics and blood biomarkers at baseline from the PEARS study were used. After appropriate data preparation, synthetic minority oversampling technique and feature selection, five machine learning algorithms were applied with five-fold cross-validated grid search optimising the balanced accuracy. Our models were explained with Shapley additive explanations to increase the trustworthiness and acceptability of the system. We developed multiple models for different use cases: theoretical (AUC-PR 0.485, AUC-ROC 0.792), GDM screening during a normal antenatal visit (AUC-PR 0.208, AUC-ROC 0.659), and remote GDM risk assessment (AUC-PR 0.199, AUC-ROC 0.656). Our models have been implemented as a web server that is publicly available for academic use. Our explainable CDSS demonstrates the potential to assist clinicians in screening at risk patients who may benefit from early pregnancy GDM prevention strategies.

Maternal Well-Being and Stage of Behaviour Change during Pregnancy: A Secondary Analysis of the PEARS Randomised Controlled Trial.

We aimed to determine whether early pregnancy well-being was associated with the stage of behaviour change during an antenatal lifestyle intervention using a secondary analysis of data from the Pregnancy Exercise and Nutrition Research Study (PEARS). Pregnant women (n = 277) with well-being data in early pregnancy were included. Maternal well-being was measured using the World Health Organisation Five-Item Well-Being Index. The intervention consisted of a mobile health (mHealth) phone application, supported by antenatal education and exercise, to prevent gestational diabetes in a population with overweight. Stage of behaviour change was measured in late pregnancy using a five-stage classification. Ordinal logistic regression was used to examine if well-being, the study group, or their interaction, were related to behaviour change. Maternal well-being (OR 1.03, 95% CI 1.01, 1.04, p < 0.01) and the study group (OR 2.25, 95% CI 1.44, 3.51, p < 0.01) both significantly influenced the positive stage of behaviour change. The probability of being at stage 5 increased from 43 to 92% as well-being increased from 0 to 100% and was higher in the intervention (53%) compared to the control (34%) group (p ≤ 0.01 (8.65, 29.27). This study demonstrates the potential importance of well-being in enabling women to engage with a healthy lifestyle, and the role that mHealth technology has in facilitating beneficial behaviour change.

Observational study of parental opinion of deferred consent for neonatal research.

OBJECTIVE: To evaluate the opinions of parents of newborns following their infant's enrolment into a neonatal research study through the process of deferred consent. DESIGN: Mixed-methods, observational study, interviewing 100 parents recently approached for deferred consent. SETTING: Tertiary-level neonatal intensive care unit, Melbourne, Australia. RESULTS: All 100 parents interviewed had consented to the study/studies using deferred consent; 62% had also experienced a prospective neonatal consent process. Eighty-nine per cent were 'satisfied' with the deferred consent process. The most common reason given for consenting was 'to help future babies'. Negative comments regarding deferred consent mostly related to the timing of the consent approach, and some related to a perceived loss of parental rights. A deferred approach was preferred by 51%, 24% preferred a prospective approach and 25% were unsure. Those who thought prospective consent would not have been preferable cited impaired decision-making, inappropriate timing of an approach before birth and their preference for removal of the decision-making burden via deferred consent. Seventy-seven per cent thought they would have given the same response if approached prospectively; those who would have declined reported that a prospective approach under stressful conditions was unwelcome and too overwhelming. CONCLUSION: In our sample, 89% of parents of infants enrolled in neonatal research using deferred consent considered it acceptable and half would not have preferred prospective consent. The ability to make a more considered decision under less stressful circumstances was key to the acceptability of deferred consent.

Limited Impact of Fetal Sex and Maternal Body Mass Index on Fetal and Maternal Insulin Resistance and Lipid Metabolism: Findings from the PEARs Study.

The intrauterine environment can have a significant impact on fetal and maternal well-being, both during pregnancy and in later life. We aimed to identify how fetal sex and maternal body mass index (BMI) influence insulin resistance and metabolic function during pregnancy with maternal BMI > 25 kg/m2. This secondary analysis assessed data from the PEARS-randomized controlled trial that recruited pregnant women with body mass indexes 25-39.9 kg/m2. Longitudinal measurements of maternal and fetal insulin resistance and metabolic function were recorded throughout pregnancy. Regression models tested the effects of fetal sex and maternal BMI on markers of metabolic function and insulin regulation. A total of 484 women and their newborns (252 (52%) males vs. 232 (48%) females) were included in the analysis. A total of 333 (69%) women were overweight and 151 (31%) were obese. Male newborns were heavier and larger than females, and had a higher rate of instrumental delivery. Males had a lower LDL, but no other markers of insulin resistance or metabolic function were affected by fetal sex. Women with obesity had elevated markers of insulin resistance and metabolic dysfunction compared with women that were overweight, but maternal BMI did not impact these variables in the fetus. Fetal sex did not impact maternal and fetal metabolic parameters in women with BMI > 25 kg/m2. However, a higher BMI caused increasingly deranged maternal blood lipid concentrations and markers of insulin resistance as pregnancy progressed. Lipid monitoring and interventions to reduce lipids during pregnancy therefore require further evaluation.

Neonatal mannequin comparison of the Upright self-inflating bag and snap-fit mask versus standard resuscitators and masks: leak, applied load and tidal volumes.

OBJECTIVE: Neonatal mask ventilation is a difficult skill to acquire and maintain. Mask leak is common and can lead to ineffective ventilation. The aim of this study was to determine whether newly available neonatal self-inflating bags and masks could reduce mask leak without additional load being applied to the face. DESIGN: Forty operators delivered 1 min episodes of mask ventilation to a mannequin using the Laerdal Upright Resuscitator, a standard Laerdal infant resuscitator (Laerdal Medical) and a T-Piece Resuscitator (Neopuff), using both the Laerdal snap-fit face mask and the standard Laerdal size 0/1 face mask (equivalent sizes). Participants were asked to use pressure sufficient to achieve 'appropriate' chest rise. Leak, applied load, airway pressure and tidal volume were measured continuously. Participants were unaware that load was being recorded. RESULTS: There was no difference in mask leak between resuscitation devices. Leak was significantly lower when the snap-fit mask was used with all resuscitation devices, compared with the standard mask (14% vs 37% leak, P<0.01). The snap-fit mask was preferred by 83% of participants. The device-mask combinations had no significant effect on applied load. CONCLUSIONS: The Laerdal Upright Resuscitator resulted in similar leak to the other resuscitation devices studied, and did not exert additional load to the face and head. The snap-fit mask significantly reduced overall leak with all resuscitation devices and was the mask preferred by participants.

A Randomized Trial of Conditioned or Unconditioned Gases for Stabilizing Preterm Infants at Birth.

OBJECTIVE: To determine whether the use of heated-humidified gases for respiratory support during the stabilization of infants <30 weeks of gestational age (GA) in the delivery room reduces rates of hypothermia on admission to the neonatal intensive care unit (NICU). STUDY DESIGN: A multicenter, unblinded, randomized trial was conducted in Melbourne, Australia, between February 2013 and June 2015. Infants <30 weeks of GA were randomly assigned to receive either heated-humidified gases or unconditioned gases during stabilization in the delivery room and during transport to NICU. Infants born to mothers with pyrexia >38°C were excluded. Primary outcome was rate of hypothermia on NICU admission (rectal temperature <36.5°C). RESULTS: A total of 273 infants were enrolled. Fewer infants in the heated-humidified group were hypothermic on admission to NICU (36/132 [27%]) compared with controls (61/141 [43%], P < .01). There was no difference in rates of hyperthermia (>37.5°C); 20% (27/132) in the heated-humidified group compared with 16% (22/141) in the controls (P = .30). There were no differences in mortality or respiratory outcomes. CONCLUSIONS: The use of heated-humidified gases in the delivery room significantly reduces hypothermia on admission to NICU in preterm infants, without increased risk of hyperthermia. CLINICAL TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Register (www.anzctr.org.au) ACTRN12613000093785.

A 20-year investigation of declining leatherback hatching success: implications of climate variation.

Unprecedented increases in air temperature and erratic precipitation patterns are predicted throughout the twenty-first century as a result of climate change. A recent global analysis of leatherback turtle hatchling output predicts that the nesting site at Sandy Point National Wildlife Refuge (SPNWR) will experience the most significant regional climate alterations. We aimed to identify how local air temperatures and precipitation patterns influenced within-nest mortality and overall hatchling output at this site between 1990 and 2010. We show that while the greatest mortality occurred during the latest stages of development (stage three), the rate of embryo mortality was highest during the initial stages (stage zero) of development (approx. 3.8 embryos per day per clutch). Increased mortality at stage three was associated with decreased precipitation and increased temperature during this developmental period, whereas precipitation prior to, and during stage zero had the greatest influence on early mortality. There was a significant decline in overall hatching success (falling from 74% to 55%) and emergence rate (calculated from the number of hatchlings that emerged from the nest as a percentage of hatched eggs) which fell from 96% to 91%. However, there was no trend observed in local temperature or precipitation during this timeframe, and neither variable was related to hatching success or emergence rate. In conclusion, our findings suggest that despite influencing within-nest mortality, climatic variability does not account for the overall decline in hatchling output at SPNWR from 1990 to 2010. Further research is therefore needed to elicit the reasons for this decline.

Histological changes in the umbilical artery following severe chorioamnionitis and funisitis may be indicative of early atherosclerosis.

We investigated whether histological evidence of early atherosclerosis was present in the umbilical artery of 21 pregnancies complicated by severe perinatal inflammation, and 21 controls matched for gestational age, sex and birth weight. Severe chorioamnionitis with funisitis was associated with increased numbers of CD68 and CD45 positive cells (both P < 0.01), indicating accumulation of monocyte-derived macrophages in lesion-susceptible regions. A down-regulation of SMA expression (P = 0.01) was also observed. These preliminary findings suggest that chorioamnionitis with funisitis may promote changes in the intima and media of the umbilical artery similar to that seen in early atherosclerosis.

The accuracy of delivery of target pressures using self-inflating bag manometers in a benchtop study.

AIM: We tested whether operators using manometers attached to self-inflating bags could accurately deliver set targeted peak inspiratory pressures (PIPs) compared to the Neopuff(™) T-piece resuscitator (TPR). METHODS: Participants provided positive pressure ventilation to a leak-free neonatal test lung at a rate of 60 inflations/min and a flow of 8 L/min. Participants used three manometers attached to self-inflating bags and a Neopuff(™) TPR to target PIPs of 20, 30 and 40 cmH2 O on each device. Mean PIPs delivered with each manometer were compared to the 'gold standard' Neopuff(™) TPR. RESULTS: In total, 13 991 inflations delivered by 20 participants were analysed. At all target PIPs, the mean PIP delivered using the Mercury Medical manometer attached to a Laerdal self-inflating bag was significantly higher by 5 cmH2 O (p < 0.01) than the Neopuff(™) TPR. The PIP delivered using both the Ambu(™) and Parker Healthcare manometers attached to their respective devices was similar to that delivered by the Neopuff(™) TPR at all targeted PIPs. CONCLUSION: Accurately targeted PIPs can be achieved when a manometer specifically designed for use on a self-inflating bag is used during manual ventilation. This may be useful in settings where access to a Neopuff(™) TPR or a gas flow source is limited.

Inflammation, lipids and aortic intima-media thickness in newborns following chorioamnionitis.

AIM: This study investigated whether chorioamnionitis was associated with increased inflammation, dyslipidaemia and adverse cardiovascular phenotypes in the immediate postnatal period. METHODS: This prospective case-control study included preterm infants (30(+0) -35(+6) weeks gestational age, GA) whose mothers did not have pregnancy-related conditions that may influence outcomes. Chorioamnionitis was diagnosed by placental histology, and infants were divided retrospectively into cases (chorioamnionitis-exposed) and controls (unexposed). Serum high-sensitivity C-reactive protein (hsCRP), lipid profile, far-wall abdominal aortic intima-media thickness (aIMT) and blood pressure (BP) were measured in the first week of life. RESULTS: There were 20 (16 male, mean GA 32.4 weeks) cases and 31 (12 male, mean GA 32.6 weeks) controls. Histological chorioamnionitis was associated with a significant increase in hsCRP and a non-significant trend towards an adverse lipid profile. There was no evidence of differences in aIMT or BP. CONCLUSION: Preterm infants exposed to chorioamnionitis have greater postnatal inflammation. There were no early postnatal differences in aIMT or BP. The inflammatory stimulus of chorioamnionitis late in gestation may be of insufficient intensity and duration to result in immediate postnatal alterations to arterial structure. Cardiovascular follow-up of infants exposed to chorioamnionitis may identify differential risk trajectories and subsequent inflammatory responses.

The impact of extended preovipositional arrest on embryonic development and hatchling fitness in the flatback sea turtle.

Turtle embryos pause development before oviposition in a process known as preovipositional arrest. Embryonic development arrests due to hypoxia (low oxygen) in the maternal oviducts and resumes only after exposure to normoxia when eggs are laid. Recently, several studies have hypothesized that the prolonged periods of preovipositional arrest may have a detrimental effect on embryo survival and development after eggs are laid. We tested this hypothesis by comparing embryo survival (determined by white spot formation and hatching success) and hatchling fitness (measured by self-righting, crawling, and swimming ability) of flatback sea turtle (Natator depressus) eggs following incubation in hypoxic (∼ 1%) and normoxic (∼ 21%) treatments for 5 d immediately following oviposition. We also measured embryo survival and hatchling fitness when eggs were incubated in hyperoxic conditions (42% oxygen), to determine whether hyperoxia could improve developmental outcome or whether some consequence of oxidative stress might manifest. Eggs incubated in hypoxia remained arrested during the 5-d treatment, and 97.5% of the eggs successfully recommenced development after exposure to normoxia when the treatment finished. At treatment commencement, 100% and 97.5% of eggs in the hyperoxic and normoxic treatments, respectively, began developing. Although hatching success was significantly lower following hypoxia (15%) compared to normoxia (80%) and hyperoxia (85%), hatchings from the hypoxic treatment were larger (carapace length and width and plastron length) than normoxic hatchlings. Similarly, hypoxic hatchings also swam significantly faster than hyperoxic hatchlings. Considering larger hatchlings may have a greater chance of survival, the production of larger hatchings may offset the high cost (lower hatching success) when preovipositional arrest is prolonged. Hyperoxia does not appear to have deleterious consequences for development.

An increasing citation black hole in ecology and evolution.

Citations published in online supplementary material (OSM) are invisible to search engines used to calculate citation counts, potentially negatively impacting popular performance indices and journal rankings that rely on citation counts for quantification. To quantify the number of citations that are "lost" in OSM, we conducted a systematic survey of supplementary citation practices in four high-ranking, society-run journals from two geographical locations (Europe and North America). In 2012, 6% of all citations were only included in the OSM and were therefore not included in citation counts. We found a significant increase in the number of references invisible to citation counting services over the last two decades. A solution to this problem is urgently required and could include journal indexing of citations in OSM or the inclusion of all references in the main text.

Neonatal resuscitation in resource-limited settings: titrating oxygen delivery without an oxygen blender.

OBJECTIVE: To test whether 4 commonly used self-inflating bags with a reservoir in situ can reliably deliver different oxygen concentrations (21%-100%) using a portable oxygen cylinder with flows of ≤5 L/min. STUDY DESIGN: Four self-inflating bags (from Laerdal, Ambu, Parker Healthcare, and Mayo Healthcare) were tested to provide positive pressure ventilation to a manikin at 60 inflations/min by 4 operators. Oxygen delivery was measured for 2 minutes, combining oxygen flows (0.25, 0.5, 1, 5 L/min) and peak inspiratory pressures (PIPs 20-25, 35-40 cmH2O). RESULTS: Combinations (n=128) were performed twice. Oxygen delivery depended upon device, oxygen flow, and PIP. All self-inflating bags delivered mean oxygen concentrations of <40% with 0.25 L/min, regardless of PIP. Three self-inflating bags delivered ≤40% with flow 0.5 L/min at PIP 35-40 cmH2O, whereas all delivered >40% at PIP 20-25 cmH2O. With 1 L/min, 3 self-inflating bags delivered 40%-60% at PIP 35-40 cmH2O and all delivered >60% at PIP 20-25 cmH2O. With 5 L/min, all self-inflating bags delivered close to or 100%, regardless of PIP. Differences in oxygen delivery between self-inflating bags were statistically significant (P<.001) even when differences were not clinically important. CONCLUSION: Self-inflating bags with a reservoir in situ can deliver a variety of oxygen concentrations without a blender, from <40% with 0.25 L/min oxygen flow to 100% with 5 L/min. The adjustment of oxygen flow may be a useful method of titrating oxygen in settings where air-oxygen blenders are unavailable.