Women's experiences of planning a vaginal breech birth in Australia

© Homer et al. Background: In many countries, planned vaginal breech birth (VBB) is a rare event. After the Term Breech Trial in 2000, VBB reduced and caesarean section for breech presentation increased. Despite this, women still request VBB. The objective of this study was to explore the experiences and decision-making processes of women who had sought a VBB. Methods: A qualitative study using descriptive exploratory design was undertaken. Twenty-two (n=22) women who planned a VBB, regardless of eventual mode of birth were recruited. The women had given birth at one of two maternity hospitals in Australia that supported VBB. In-depth, semi-structured interviews using an interview guide were conducted. Interviews were analysed thematically. Results: Twenty two women were interviewed; three quarters were primiparous (n=16; 73%). Nine (41%) were already attending a hospital that supported VBB with the remaining women moving hospitals. All women actively sought a vaginal breech birth because the baby remained breech after an external cephalic version - 12 had a vaginal birth (55%) and 10 (45%) a caesarean section after labour commenced. There were four main themes: Reacting to a loss of choice and control, Wanting information that was trustworthy, Fighting the system and seeking support for VBB and The importance of 'having a go' at VBB. Conclusions: Women seeking a VBB value clear, consistent and relevant information in deciding about mode of birth. Women desire autonomy to choose vaginal breech birth and to be supported in their choice with high quality care

Multilayer metamaterial absorbers inspired by perfectly matched layers

We derive periodic multilayer absorbers with effective uniaxial properties similar to perfectly matched layers (PML). This approximate representation of PML is based on the effective medium theory and we call it an effective medium PML (EM-PML). We compare the spatial reflection spectrum of the layered absorbers to that of a PML material and demonstrate that after neglecting gain and magnetic properties, the absorber remains functional. This opens a route to create electromagnetic absorbers for real and not only numerical applications and as an example we introduce a layered absorber for the wavelength of $8$~$\mu$m made of SiO$_2$ and NaCl. We also show that similar cylindrical core-shell nanostructures derived from flat multilayers also exhibit very good absorptive and reflective properties despite the different geometry

SUMO chain formation is required for response to replication arrest in S. pombe

SUMO is a ubiquitin-like protein that is post-translationally attached to one or more lysine residues on target proteins. Despite having only 18% sequence identity with ubiquitin, SUMO contains the conserved betabetaalphabetabetaalphabeta fold present in ubiquitin. However, SUMO differs from ubiquitin in having an extended N-terminus. In S. pombe the N-terminus of SUMO/Pmt3 is significantly longer than those of SUMO in S. cerevisiae, human and Drosophila. Here we investigate the role of this N-terminal region. We have used two dimensional gel electrophoresis to demonstrate that S. pombe SUMO/Pmt3 is phosphorylated, and that this occurs on serine residues at the extreme N-terminus of the protein. Mutation of these residues (in pmt3-1) results in a dramatic reduction in both the levels of high Mr SUMO-containing species and of total SUMO/Pmt3, indicating that phosphorylation of SUMO/Pmt3 is required for its stability. Despite the significant reduction in high Mr SUMO-containing species, pmt3-1 cells do not display an aberrant cell morphology or sensitivity to genotoxins or stress. Additionally, we demonstrate that two lysine residues in the N-terminus of S. pombe SUMO/Pmt3 (K14 and K30) can act as acceptor sites for SUMO chain formation in vitro. Inability to form SUMO chains results in aberrant cell and nuclear morphologies, including stretched and fragmented chromatin. SUMO chain mutants are sensitive to the DNA synthesis inhibitor, hydroxyurea (HU), but not to other genotoxins, such as UV, MMS or CPT. This implies a role for SUMO chains in the response to replication arrest in S. pomb

Statistically validated networks in bipartite complex systems

Many complex systems present an intrinsic bipartite nature and are often described and modeled in terms of networks [1-5]. Examples include movies and actors [1, 2, 4], authors and scientific papers [6-9], email accounts and emails [10], plants and animals that pollinate them [11, 12]. Bipartite networks are often very heterogeneous in the number of relationships that the elements of one set establish with the elements of the other set. When one constructs a projected network with nodes from only one set, the system heterogeneity makes it very difficult to identify preferential links between the elements. Here we introduce an unsupervised method to statistically validate each link of the projected network against a null hypothesis taking into account the heterogeneity of the system. We apply our method to three different systems, namely the set of clusters of orthologous genes (COG) in completely sequenced genomes [13, 14], a set of daily returns of 500 US financial stocks, and the set of world movies of the IMDb database [15]. In all these systems, both different in size and level of heterogeneity, we find that our method is able to detect network structures which are informative about the system and are not simply expression of its heterogeneity. Specifically, our method (i) identifies the preferential relationships between the elements, (ii) naturally highlights the clustered structure of investigated systems, and (iii) allows to classify links according to the type of statistically validated relationships between the connected nodes.Comment: Main text: 13 pages, 3 figures, and 1 Table. Supplementary information: 15 pages, 3 figures, and 2 Table

Volume-Targeted Ventilation and Arterial Carbon Dioxide in Neonates

Objectives: To review the arterial carbon dioxide tensions (PaCO2) in newborn infants ventilated using synchronized intermittent mandatory ventilation (SIMV) in volume guarantee mode (using the Drager Babylog 8000+) with a unit policy targeting tidal volumes of approximately 4 mL/kg. Methods: Data on ventilator settings and arterial (PaCO2 levels were collected on all arterial blood gases (ABG; n = 288) from 50 neonates ( 65 mmHg) were determined. Results: The mean (SD) (PaCO2 during the first 48 h was 46.6 (9.0) mmHg. The mean (SD) (PaCO2 on the first blood gas of those infants commenced on volume guarantee from admission was 45.1 (12.5) mmHg. Severe hypo- or hypercapnoea occurred in 8% of infants at the time of their first blood gas measurement, and i

A comparison of body composition assessment methods in climbers: Which is better?

Objective To compare body composition estimations of field estimation methods: Durnin & Womersley anthropometry (DW-ANT), bioelectrical impedance analysis (BIA) and Deborah-Kerr anthropometry (DK-ANT) against dual-energy X-ray absorptiometry (DXA) in a male Chilean sport climbing sample. Methods 30 adult male climbers of different performance levels participated in the study. A DXA scan (Lunar Prodigy (R)) was used to determine fat mass, lean mass and total bone mineral content (BMC). Total muscle mass (MM, kg) was estimated through a validated prediction model. DW-ANT and BIA ("non-athletes" and "athletes" equations) were used to determinate fat mass percentage (FM %), while DK-ANT was utilized to estimate MM and BMC. Results A significant (p<0.01) inter-method difference was observed for all methods analyzed. When compared to DXA, DW-ANT and BIA underestimated FM% and DK-ANT overestimated MM and BMC (All p< 0.01). The inter-method differences was lower for DW-ANT. Discussion We found that body composition estimation in climbers is highly method dependent. If DXA is not available, DW-ANT for FM% has a lower bias of estimation than BIA in young male Chilean climbers. For MM and BMC, further studies are needed to compare and estimate the DK-ANT bias level. For both methods, correction equations for specific climbing population should be considered

Who mixes with whom among men who have sex with men? Implications for modelling the HIV epidemic in southern India

In India, the identity of men who have sex with men (MSM) is closely related to the role taken in anal sex (insertive, receptive or both), but little is known about sexual mixing between identity groups. Both role segregation (taking only the insertive or receptive role) and the extent of assortative (within-group) mixing are known to affect HIV epidemic size in other settings and populations. This study explores how different possible mixing scenarios, consistent with behavioural data collected in Bangalore, south India, affect both the HIV epidemic, and the impact of a targeted intervention. Deterministic models describing HIV transmission between three MSM identity groups (mostly insertive Panthis/Bisexuals, mostly receptive Kothis/Hijras and versatile Double Deckers), were parameterised with behavioural data from Bangalore. We extended previous models of MSM role segregation to allow each of the identity groups to have both insertive and receptive acts, in differing ratios, in line with field data. The models were used to explore four different mixing scenarios ranging from assortative (maximising within-group mixing) to disassortative (minimising within-group mixing). A simple model was used to obtain insights into the relationship between the degree of within-group mixing, R0 and equilibrium HIV prevalence under different mixing scenarios. A more complex, extended version of the model was used to compare the predicted HIV prevalence trends and impact of an HIV intervention when fitted to data from Bangalore. With the simple model, mixing scenarios with increased amounts of assortative (within-group) mixing tended to give rise to a higher R0 and increased the likelihood that an epidemic would occur. When the complex model was fit to HIV prevalence data, large differences in the level of assortative mixing were seen between the fits identified using different mixing scenarios, but little difference was projected in future HIV prevalence trends. An oral pre-exposure prophylaxis (PrEP) intervention was modelled, targeted at the different identity groups. For intervention strategies targeting the receptive or receptive and versatile MSM together, the overall impact was very similar for different mixing patterns. However, for PrEP scenarios targeting insertive or versatile MSM alone, the overall impact varied considerably for different mixing scenarios; more impact was achieved with greater levels of disassortative mixing

Plastic microfibre ingestion by deep-sea organisms

Plastic waste is a distinctive indicator of the world-wide impact of anthropogenic activities. Both macro- and micro-plastics are found in the ocean, but as yet little is known about their ultimate fate and their impact on marine ecosystems. In this study we present the first evidence that microplastics are already becoming integrated into deep-water organisms. By examining organisms that live on the deep-sea floor we show that plastic microfibres are ingested and internalised by members of at least three major phyla with different feeding mechanisms. These results demonstrate that, despite its remote location, the deep sea and its fragile habitats are already being exposed to human waste to the extent that diverse organisms are ingesting microplastics

The relationship between parent and child dysfunctional beliefs about sleep and child sleep

Cognitive theories emphasise the role of dysfunctional beliefs about sleep in the development and maintenance of sleep-related problems (SRPs). The present research examines how parents' dysfunctional beliefs about children's sleep and child dysfunctional beliefs about sleep are related to each other and to children's subjective and objective sleep. Participants were 45 children aged 11 -12 years and their parents. Self-report measures of dysfunctional beliefs about sleep and child sleep were completed by children, mothers and fathers. Objective measures of child sleep were taken using actigraphy. The results showed that child dysfunctional beliefs about sleep were correlated with father (r=.43, p<.05) and mother (r=.43, p<.05) reported child SRPs, and with Sleep Onset Latency (r=.34, p<.05). Maternal dysfunctional beliefs about child sleep were related to child SRPs as reported by mothers (r=.44, p<.05), and to child dysfunctional beliefs about sleep (r=.37, p<.05). Some initial evidence was found for a mediation pathway in which child dyfunctional beliefs mediate the relationship between parent dysfunctional beliefs and child sleep. The results support the cognitive model of SRPs and contribute to the literature by providing the first evidence of familial aggregation of dysfunctional beliefs about sleep