Suburban solutions: The other side of the story

How much does urban form affect levels of active travel and transport carbon emissions? It is all too easy for policy-makers to jump to simple conclusions, but the answer is both complex and contested. Here Hugh Barton, Marcus Grant and Michael Horswell report on recent research which casts new light on the impact of neighbourhood planning

Exploratory laparotomy in the management of confirmed necrotizing enterocolitis

Introduction: Necrotizing enterocolitis (NEC) is a serious gastrointestinal emergency in newborn infants. Surgical management includes primary peritoneal drainage and/or exploratory laparotomy with bowel resection. This study describes obstetric complications, postnatal comorbidities, surgical care and intermediate postoperative outcomes in all infants with surgically and/or histologically proven NEC, who underwent exploratory laparotomy at our tertiary referral centre.Materials and methods: We conducted a retrospective review between January 2005 and December 2010. Results are reported as median (range). Fisher’s exact test (two tailed) was used for statistical analysis. A P-value of 0.05 or less was considered statistically significant.Results: A total of 71 infants had suspected (Bell’s stageZ1) NEC. Of them, 32 infants underwent laparotomy for stage 2–3 NEC. We excluded 11 infants with surgically and/or histologically proven spontaneous intestinal perforation. In the remaining 21 infants with confirmed NEC, median gestational age was 27 weeks (23–39 weeks) and median birth weight was 720 g (440–3510 g). NEC was suspected after a median 14 days of life (1–49 days of life). Fifteen patients (71%) were initially managed medically for a median total of 8 days (1–25 days). Laparotomy was performed after a median of 7 days (<1–35 days) from the suspicion of NEC. Eleven infants (52%) underwent bowel resection and enterostomy, four infants (19%) underwent  bowel resection with primary anastomosis and one infant (5%) underwent proximal diverting jejunostomy. Bowel perforation was seen in seven patients (33%). Necrosis totalis was evident in five patients (24%). There were 12 postoperative deaths (57% mortality), and seven deaths (58%) occurred during the first 30 days. Infants who died were more likely to have had absent/reversed enddiastolic flow (n=5, P= 0.64), intrauterine growth retardation (n=5, P = 0.18) or a gestational birth weight between 501 and 750 g (n=9, P = 0.08). In the surviving children (n= 9), the median length of hospital stay was 134 days (87–190 days) and postoperative sequelae were frequently seen.Conclusion: The morbidity and mortality for infants with confirmed NEC who undergo laparotomy remain high in infants despite optimal medical and surgical care. Keywords: exploratory laparotomy, necrotizing enterocolitis, surger

Modelling the effects of gravity waves on stratocumulus clouds observed during VOCALS-UK

During the VOCALS campaign spaceborne satellite observations showed that travelling gravity wave packets, generated by geostrophic adjustment, resulted in perturbations to marine boundary layer (MBL) clouds over the south-east Pacific Ocean (SEP). Often, these perturbations were reversible in that passage of the wave resulted in the clouds becoming brighter (in the wave crest), then darker (in the wave trough) and subsequently recovering their properties after the passage of the wave. However, occasionally the wave packets triggered irreversible changes to the clouds, which transformed from closed mesoscale cellular convection to open form. In this paper we use large eddy simulation (LES) to examine the physical mechanisms that cause this transition. Specifically, we examine whether the clearing of the cloud is due to (i) the wave causing additional cloud-top entrainment of warm, dry air or (ii) whether the additional condensation of liquid water onto the existing drops and the subsequent formation of drizzle are the important mechanisms. We find that, although the wave does cause additional drizzle formation, this is not the reason for the persistent clearing of the cloud; rather it is the additional entrainment of warm, dry air into the cloud followed by a reduction in longwave cooling, although this only has a significant effect when the cloud is starting to decouple from the boundary layer. The result in this case is a change from a stratocumulus to a more patchy cloud regime. For the simulations presented here, cloud condensation nuclei (CCN) scavenging did not play an important role in the clearing of the cloud. The results have implications for understanding transitions between the different cellular regimes in marine boundary layer (MBL) clouds

OH detection by absorption of frequency-doubled diode laser radiation at 308nm

Radiation at 308 nm has been obtained by frequency doubling the output of a commercial diode laser cooled to 165 K. A single pass through a crystal of LiIO3 converted 1 mW of 616 nm radiation to 50 pW of UV, and this was used to detect the OH radical in absorption in a flow tube. Possible extensions of the method for detection of OH in the atmosphere are discussed

Hemostatic efficacy of an advanced bipolar sealer in open gynecologic, thoracic, and colectomy procedures: A prospective cohort study

Background An advanced bipolar (ABP) tissue sealer designed for division of major vessels in open procedures was evaluated in a prospective post-market study. The objective was to provide clinical data for assessment of vessel transection, hemostatic performance and ease of use of the ABP device during open colectomy, gynecologic, and thoracic operations. Materials and methods The ABP test device was used in colectomy (n = 36), gynecologic (n = 44), and thoracic (n = 21) procedure groups. Vessels transected with the ABP device were graded intraoperatively on a hemostasis scale of 1–4, defined as follows: Grade1, no bleeding; Grade 2, minor bleeding with no intervention; Grade 3, minor bleeding requiring touchup with the test device or monopolar cautery; and Grade 4, significant bleeding requiring intervention with any additional hemostatic product. The primary performance measure was the percentage of vessels that achieved hemostasis grades ≤3. The primary safety endpoint was the summarization of all ABP device-related adverse events (AEs). Results For all three procedure groups together, 302 (96.2%) of 314 total vessel transections were scored as hemostasis grades ≤ 3, including 270 (86.0%) that were rated Grade 1. Twelve transections (3.8%) were Grade 4, which included 9 vessels transected in the gynecologic group and 3 in the thoracic group. Three subjects experienced a total of 4 device-related AEs, consisting of hematoma, hypotension, procedural pain, and superficial thermal burn. All 4 device-related AEs were mild in severity. Conclusion The advanced bipolar device exhibited effective hemostasis, an acceptable safety profile, and ease of use during colectomy, thoracic, and gynecologic procedures

Revisiting Consumer Ethnocentrism: Review, Reconceptualization, and Empirical Testing

Prior research has suggested that many consumers prefer domestic to foreign products, even when the quality is lower and the price is higher. Such bias is attributed to consumer ethnocentrism. This study critically examines the current conceptualizations of consumer ethnocentrism and proposes an extension of its conceptual boundaries and measurement. It determines that consumer ethnocentrism is a multidimensional construct that encompasses five dimensions: prosociality, cognition, insecurity, reflexiveness, and habituation. Empirical evidence from the United Kingdom and the United States demonstrates that the extended measurement instrument better predicts consumers' preferences for local brands at the expense of foreign brands

T-REX: software for the processing and analysis of T-RFLP data

Softwar

Likely Health Outcomes for Untreated Acute Febrile Illness in the Tropics in Decision and Economic Models; A Delphi Survey

BACKGROUND: Modelling is widely used to inform decisions about management of malaria and acute febrile illnesses. Most models depend on estimates of the probability that untreated patients with malaria or bacterial illnesses will progress to severe disease or death. However, data on these key parameters are lacking and assumptions are frequently made based on expert opinion. Widely diverse opinions can lead to conflicting outcomes in models they inform. METHODS AND FINDINGS: A Delphi survey was conducted with malaria experts aiming to reach consensus on key parameters for public health and economic models, relating to the outcome of untreated febrile illnesses. Survey questions were stratified by malaria transmission intensity, patient age, and HIV prevalence. The impact of the variability in opinion on decision models is illustrated with a model previously used to assess the cost-effectiveness of malaria rapid diagnostic tests. Some consensus was reached around the probability that patients from higher transmission settings with untreated malaria would progress to severe disease (median 3%, inter-quartile range (IQR) 1-5%), and the probability that a non-malaria illness required antibiotics in areas of low HIV prevalence (median 20%). Children living in low transmission areas were considered to be at higher risk of progressing to severe malaria (median 30%, IQR 10-58%) than those from higher transmission areas (median 13%, IQR 7-30%). Estimates of the probability of dying from severe malaria were high in all settings (medians 60-73%). However, opinions varied widely for most parameters, and did not converge on resurveying. CONCLUSIONS: This study highlights the uncertainty around potential consequences of untreated malaria and bacterial illnesses. The lack of consensus on most parameters, the wide range of estimates, and the impact of variability in estimates on model outputs, demonstrate the importance of sensitivity analysis for decision models employing expert opinion. Results of such models should be interpreted cautiously. The diversity of expert opinion should be recognised when policy options are debated

Neptunism and transformism:Robert Jameson and other evolutionary theorists in early nineteenth-century Scotland

This paper sheds new light on the prevalence of evolutionary ideas in Scotland in the early nineteenth century and establish what connections existed between the espousal of evolutionary theories and adherence to the directional history of the earth proposed by Abraham Gottlob Werner and his Scottish disciples. A possible connection between Wernerian geology and theories of the transmutation of species in Edinburgh in the period when Charles Darwin was a medical student in the city was suggested in an important 1991 paper by James Secord. This study aims to deepen our knowledge of this important episode in the history of evolutionary ideas and explore the relationship between these geological and evolutionary discourses. To do this it focuses on the circle of natural historians around Robert Jameson, Wernerian geologist and professor of natural history at the University of Edinburgh from 1804 to 1854. From the evidence gathered here there emerges a clear confirmation that the Wernerian model of geohistory facilitated the acceptance of evolutionary explanations of the history of life in early nineteenth-century Scotland. As Edinburgh was at this time the most important center of medical education in the English-speaking world, this almost certainly influenced the reception and development of evolutionary ideas in the decades that followed.</p

Hundreds of variants clustered in genomic loci and biological pathways affect human height

Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.