Climate-driven range shifts explain the distribution of extant gene pools and predict future loss of unique lineages in a marine brown alga.

The climate-driven dynamics of species ranges is a critical research question in evolutionary ecology. We ask whether present intraspecific diversity is determined by the imprint of past climate. This is an ongoing debate requiring interdisciplinary examination of population genetic pools and persistence patterns across global ranges. Previously, contrasting inferences and predictions have resulted from distinct genomic coverage and/or geographical information. We aim to describe and explain the causes of geographical contrasts in genetic diversity and their consequences for the future baseline of the global genetic pool, by comparing present geographical distribution of genetic diversity and differentiation with predictive species distribution modelling (SDM) during past extremes, present time and future climate scenarios for a brown alga, Fucus vesiculosus. SDM showed that both atmospheric and oceanic variables shape the global distribution of intertidal species, revealing regions of persistence, extinction and expansion during glacial and postglacial periods. These explained the distribution and structure of present genetic diversity, consisting of differentiated genetic pools with maximal diversity in areas of long-term persistence. Most of the present species range comprises postglacial expansion zones and, in contrast to highly dispersive marine organisms, expansions involved only local fronts, leaving distinct genetic pools at rear edges. Besides unravelling a complex phylogeographical history and showing congruence between genetic diversity and persistent distribution zones, supporting the hypothesis of niche conservatism, range shifts and loss of unique genetic diversity at the rear edge were predicted for future climate scenarios, impoverishing the global gene pool.

Quantification of risk of emergency caesarean during labour after one previous caesarean section.

In its 2007 guideline, the Royal College of Obstetricians and Gynaecologists (RCOG) recommends vaginal birth after caesarean (VBAC) as safer than repeat elective caesarean sections. However, this document does not give details of risk of emergency caesarean section for women accepting VBAC. An emergency caesarean is associated with increased maternal and neonatal morbidity, and women do consider the eventuality of emergency delivery when deciding mode of delivery. We sought to quantify this risk by designing a retrospective cohort study in a consultant-led unit. While higher than average rates of successful planned VBAC were achieved, the odds of emergency caesarean delivery were increased in women undergoing VBAC (OR 3.0, 95% CI 1.2-7.6, p = 0.03). Odds of requiring a Category 1 emergency caesarean were markedly raised. Our data adds to the VBAC literature by quantifying the risk of Category 1 or 2 emergency caesarean section for women entering labour who have delivered by caesarean section once previously, giving the odds of emergency caesarean section on entering labour compared with women without a scar. This gives further information to those counselling women about birth after caesarean section.

Loss of a globally unique kelp forest from Oman.

Kelp forests are declining in many regions globally with climatic perturbations causing shifts to alternate communities and significant ecological and economic loss. Range edge populations are often at most risk and are often only sustained through localised areas of upwelling or on deeper reefs. Here we document the loss of kelp forests (Ecklonia radiata) from the Sultanate of Oman, the only confirmed northern hemisphere population of this species. Contemporary surveys failed to find any kelp in its only known historical northern hemisphere location, Sadah on the Dhofar coast. Genetic analyses of historical herbarium specimens from Oman confirmed the species to be E. radiata and revealed the lost population contained a common CO1 haplotype found across South Africa, Australia and New Zealand suggesting it once established through rapid colonisation throughout its range. However, the Omani population also contained a haplotype that is found nowhere else in the extant southern hemisphere distribution of E. radiata. The loss of the Oman population could be due to significant increases in the Arabian Sea temperature over the past 40 years punctuated by suppression of coastal upwelling. Climate-mediated warming is threatening the persistence of temperate species and precipitating loss of unique genetic diversity at lower latitudes.

Exploring the response of a key Mediterranean gorgonian to heat stress across biological and spatial scales.

Understanding the factors and processes that shape intra-specific sensitivity to heat stress is fundamental to better predicting the vulnerability of benthic species to climate change. Here, we investigate the response of a habitat-forming Mediterranean octocoral, the red gorgonian Paramuricea clavata (Risso, 1826) to thermal stress at multiple biological and geographical scales. Samples from eleven P. clavata populations inhabiting four localities separated by hundreds to more than 1500 km of coast and with contrasting thermal histories were exposed to a critical temperature threshold (25 °C) in a common garden experiment in aquaria. Ten of the 11 populations lacked thermotolerance to the experimental conditions provided (25 days at 25 °C), with 100% or almost 100% colony mortality by the end of the experiment. Furthermore, we found no significant association between local average thermal regimes nor recent thermal history (i.e., local water temperatures in the 3 months prior to the experiment) and population thermotolerance. Overall, our results suggest that local adaptation and/or acclimation to warmer conditions have a limited role in the response of P. clavata to thermal stress. The study also confirms the sensitivity of this species to warm temperatures across its distributional range and questions its adaptive capacity under ocean warming conditions. However, important inter-individual variation in thermotolerance was found within populations, particularly those exposed to the most severe prior marine heatwaves. These observations suggest that P. clavata could harbor adaptive potential to future warming acting on standing genetic variation (i.e., divergent selection) and/or environmentally-induced phenotypic variation (i.e., intra- and/or intergenerational plasticity).

Evolution and diversification within the intertidal brown macroalgae Fucus spiralis/F. vesiculosus species complex in the North Atlantic.

We examined 733 individuals of Fucusspiralis from 21 locations and 1093 Fucusvesiculosus individuals from 37 locations throughout their northern hemisphere ranges using nuclear and mitochondrial markers. Three genetic entities of F. spiralis were recovered. In northern and sympatric populations, the presence of "F. spiralis Low" in the mid-intertidal and "F. spiralis High" in the high-intertidal was confirmed and both co-occurred with the sister species F. vesiculosus. The third and newly-discovered entity, "F. spiralis South", was present mainly in the southern range, where it did not co-occur with F. vesiculosus. The South entity diverged early in allopatry, then hybridized with F. vesiculosus in sympatry to produce F. spiralis Low. Ongoing parallel evolution of F. spiralis Low and F. spiralis High is most likely due to habitat preference/local selection and maintained by preferentially selfing reproductive strategies. Contemporary populations of F. spiralis throughout the North Atlantic stem from a glacial refugium around Brittany involving F. spiralis High; F. spiralis South was probably unaffected by glacial episodes. Exponential population expansion for F. vesiculosus began during the Cromer and/Holstein interglacial period (300,000-200,000 yrs BP). Following the last glacial maximum (30,000-22,000 yrs BP), a single mtDNA haplotype from a glacial refugium in SW Ireland colonized Scandinavia, the Central Atlantic islands, and the W Atlantic.

A transcriptome resource for the copepod Calanus glacialis across a range of culture temperatures.

The copepod Calanus glacialis plays a key role in the Arctic pelagic ecosystem. Despite its ecological importance and ongoing climate changes, limited knowledge at the genomic level has hindered the understanding of the molecular processes underlying environmental stress responses and ecological adaptation. Transcriptome data was generated from an experiment with C. glacialis copepodite (CV) subjected to five different temperatures. We obtained a total of 512,352 high-quality 454 pyrosequencing reads, which were assembled into 55,562 contigs distributed in 128 KEGG pathways. Functional analysis revealed numerous genes related to diverse biological functions and processes, including members of all major conserved signaling pathways. Comparative analysis of acclimated individuals to experimental temperatures has provided information about gene variations observed in several pathways (e.g. genes involved in energy, lipid and amino acid metabolism were shown to be down-regulated with increasing temperatures). These mRNA sequence resources will facilitate further studies on genomics and physiology-driven molecular processes in C. glacialis and related species.

Evaluation of nuclear magnetic resonance spectroscopy for determination of deuterium abundance in body fluids: application to measurement of total-body water in human infants.

Nuclear magnetic resonance (NMR) spectroscopy was used to quantitate abundance of 2H in body water of human infants. This method provides precise measurement of total-body water without the extensive sample preparation requirements of previously described methods for determination of 2H content in body fluids. 2H2O (1 g/kg body weight) was administered to infants and saliva and urine were collected for up to 5 h. An internal standard was added directly to the fluid specimen and 2H enrichment in water was measured by NMR spectroscopy. Working range of deuterium abundance was 0.04-0.32 atom %. Coefficients of variation for saliva samples at 0.20 atom % 2H was 1.97%. 2H content in urine and saliva water reached a plateau by 4 h after administration, and amounts in the two fluids were virtually identical. Mean total-body water determination for six infants was 58.3 +/- 5.8% of body weight (range 53-66%).

Childhood pulmonary alveolar proteinosis. Extracorporeal membrane oxygenation with total cardiopulmonary support during bronchopulmonary lavage.

Partial cardiopulmonary bypass with extracorporeal membrane oxygenation to allow bilateral bronchopulmonary lavage in pulmonary alveolar proteinosis has been described. However, this technique is complicated by a very low arterial PO2 and cardiovascular embarrassment. Total cardiopulmonary support avoids these problems and was successfully used in a 2 1/2-year-old girl.

Bronchopulmonary infection with Moraxella catarrhalis in infants requiring extracorporeal membrane oxygenation.

Moraxella (formerly Branhamella) catarrhalis is now a well-recognized pathogen of the upper and lower respiratory tract. Four pediatric cases of life-threatening pneumonia requiring extracorporeal membrane oxygenation are presented. M. Catarrhalis was isolated within 48 hours of admission in three of the cases and within 24 hours of an acute deterioration in the fourth. We conclude that M. catarrhalis is either a significant pathogen in its own right, a marker of severe disease, or a secondary invader.

Salvage of postoperative pulmonary hypertensive crisis using ECMO via cervical cannulation in a case of truncus arteriosus.

The survival of patients with truncus arteriosus beyond one year of age is rare without surgical treatment [3 . Early surgery may be associated with a mortality but is still preferable, as the risks of established pulmonary hypertensive disease complicate delayed surgery [2]. We report the successful salvage of a pulmonary hypertensive crisis 24 h after corrective surgery in a late presenting patient using extracorporeal membrane oxygenation (ECMO) via cervical cannulation. Post-operative pulmonary hypertensive crises may present a difficult management problem. Extracorporeal membrane oxygenation is therapeutic in these circumstances in addition to providing life support. Cervical cannulation remains the method of choice in the postoperative cardiac patient.

Extracorporeal membrane oxygenation and the treatment of critical pulmonary hypertension in congenital heart disease.

Certain forms of congenital heart disease (CHD) confer a high risk for the development of severe pulmonary hypertension before and after corrective cardiac surgery. Extracorporeal membrane oxygenation (ECMO) has theoretical benefits in the treatment of this complication in that it assures oxygenation, corrects acid-base balance and provides haemodynamic support at the same time as allowing lung rest from ventilation. We examined our experience of the 117 children and neonates supported with ECMO between November 1989 and July 1993. Of these, five received support for critical pulmonary hypertension associated with congenital heart disease. They comprised three who had undergone surgical repair of CHD, one whose total anomalous pulmonary venous drainage was diagnosed and corrected whilst on ECMO and one neonate with functional pulmonary atresia. Pulmonary artery pressure (PAP) was estimated by Doppler echocardiography in all patients and confirmed invasively in two. The median systolic PAP was 46 (range 42-65) mmHg prior to ECMO. The median ratio of pulmonary to systemic arterial pressure (PAP/SAP) was 0.75 (0.70-0.92). Following ECMO of 16-120 h duration, the median systolic PAP was 34 (30-49) mmHg with PAP/SAP 0.50 (0.35-0.60). All patients survived and there were no complications related to ECMO. Extracorporeal membrane oxygenation is an effective treatment in critical pulmonary hypertension and should be considered in all patients in whom this is refractory to conventional measures.

Refresher courses for the 21st century.

One hundred eighty-one (n = 181) nurses who completed the Rutgers Nurse Refresher course between the years of 1991 and 1994 were surveyed to determine the outcome of the course in relation to successor return to nursing practice. Of the number of nurses who responded (n = 111), 78 nurses (70.2%) returned to practice as RNs. Nurses who completed the course in 1991 and 1992 had higher employment rates as RNs than those nurses who completed the course in 1993 and 1994. Of the 78 nurses who found employment as RNs, 55 nurses (71%) found employment in other-than-hospital settings. An increase in employment in long-term care and other settings, such an physician offices and school nursing was found when the data were analyzed by setting and year of course completion. Findings of the survey are discussed in relationship to changes in health care delivery as well as recommendations for curriculum revision.

Blood loss and blood transfusion at caesarean section: a prospective observational study covering 30 years.

OBJECTIVE: Attitudes to acute blood loss and transfusion have changed during the last 40 years. This study observed the trends in blood loss and transfusion rates at caesarean section during that period to identify any trends between 1976 and 2006. STUDY DESIGN: Prospective analysis of clinical notes of women delivered by caesarean sections in a major district hospital obstetric unit in the UK, delivering around 6000 annually during four 12-month periods every 10 years from 1976 to 2006. Details including demographic, pregnancy, delivery, blood loss, transfusion, and puerperal observations were recorded. RESULTS: 3222 of 22,998 women were delivered by caesarean section during the four study years, increasing from 7.2% in 1976 to 23.4% in 2006 (P<0.001). The median recorded blood loss was 500ml, which did not change significantly over the study years. The rate of excess blood loss however increased in low-risk cases in 2006 compared with 1996 (P<0.001); this increase followed the recommended restricted intra-operative oxytocin dose. Transfusion rates declined significantly from 22% in 1976 to 4-5% in 1996 and 2006 (P<0.001). CONCLUSIONS: Median blood loss remained steady for each of the study years but with an increase in excess blood loss cases in the last study year compared with the two previous study years. The explanation for this is presently uncertain, but was possibly influenced by the 2001 recommendation for a reduced dose of oxytocin at delivery. Transfusion rates declined, probably precipitated by anxieties over infections associated blood products. There was no indication of increased morbidity with the reduced transfusion rates accessed by the surrogate of post-delivery discharge times.

How children die: classifying child deaths.

AIM: To validate a descriptive tool for the causes of child death, which was designed to circumvent problems posed by the analysis of a confidential enquiry. METHOD: 3 participants from different healthcare backgrounds used clinical data, including the entries on the medical certificate of the cause of death, to classify the root cause of 783 deaths from the Confidential Enquiry into Maternal and Child Health child death review. A bespoke hierarchical system was used. Unanimity of allocation within categories and inter-rater and intra-rater agreement were assessed. Two methods for treating disagreements were compared by assessing their effect upon the apparent incidence of different causes of death. RESULTS: The participants were most consistent in grouping deaths due to trauma, malignancy and sudden infant death. Each was highly consistent in allocating cases to groups (κ 0.85-0.99), but the agreement between participants, although "good", was worse (κ 0.66-0.78). The greatest number of discrepancies was between diseases identified as congenital by the doctor and as chronic medical conditions by others. The method for treating disagreement between participants does not affect the commonest cause of death (trauma) but alters the ranking of the subordinate causes. CONCLUSION: Agreement within diagnostic categories might be improved by greater training of assessors in the use of the technique. This level of performance compares well with that of other coding systems upon their target groups.

Why children die: avoidable factors associated with child deaths.

AIM: To describe the avoidable factors associated with child deaths identified by a confidential enquiry. METHOD: In the Centre for Maternal and Child Enquiries confidential enquiry, a sample (13%) of cases was subjected to case note review by multidisciplinary panels attempting to identify avoidable factors associated with the deaths. Cases were selected blindly but in equal numbers from predetermined age bands and participating regions. The anonymised records were reviewed in regions remote to where the child lived and died. Panel composition, conduct and reporting were standardised. RESULTS: 119 of 126 cases reviewed by enquiry panels had sufficient information to determine avoidable factors. These cases were comparable with the whole dataset in terms of sex and causes of death. 31 (26%) of 119 had avoidable factors that were predominantly related to individuals or agencies with a direct responsibility to the child. 51 (43%) of 119 were defined as potentially avoidable. In all, 130 factors were considered in relation to these 82 cases, and 64% of the factors were healthcare related. Avoidable factors were more likely where life-limiting illness was not present. Recurring avoidable factors included failure to recognise serious illness at the point of presentation and death occurring in children who had been lost to follow-up. CONCLUSION: Child Death Overview Panels now have the responsibility to review child deaths using similar methods but relying upon data forms rather than the case record. Analysis of contributory factors on a national scale has the potential to improve understanding of why children die and indicate strategies to reduce child mortality.