Establishing the safety of waterbirth for mothers and babies: a cohort study with nested qualitative component: the protocol for the POOL study

Introduction Approximately 60 000 (9/100) infants are born into water annually in the UK and this is likely to increase. Case reports identified infants with water inhalation or sepsis following birth in water and there is a concern that women giving birth in water may sustain more complex perineal trauma. There have not been studies large enough to show whether waterbirth increases these poor outcomes. The POOL Study (ISRCTN13315580) plans to answer the question about the safety of waterbirths among women who are classified appropriate for midwifery-led intrapartum care. Methods and analysis A cohort study with a nested qualitative component. Objectives will be answered using retrospective and prospective data captured in electronic National Health Service (NHS) maternity and neonatal systems. The qualitative component aims to explore factors influencing pool use and waterbirth; data will be gathered via discussion groups, interviews and case studies of maternity units. Ethics and dissemination The protocol has been approved by NHS Wales Research Ethics Committee (18/WA/0291) the transfer of identifiable data has been approved by Health Research Authority Confidentiality Advisory Group (18CAG0153). Study findings and innovative methodology will be disseminated through peer-reviewed journals, conferences and events. Results will be of interest to the general public, clinical and policy stakeholders in the UK and will be disseminated accordingly

Opening a new window to other worlds with spectropolarimetry

A high level of diversity has already been observed among the planets of our own Solar System. As such, one expects extrasolar planets to present a wide range of distinctive features, therefore the characterisation of Earth- and super Earth-like planets is becoming of key importance in scientific research. The SEARCH (Spectropolarimetric Exoplanet AtmospheRe CHaracerisation) mission proposal of this paper represents one possible approach to realising these objectives. The mission goals of SEARCH include the detailed characterisation of a wide variety of exoplanets, ranging from terrestrial planets to gas giants. More specifically, SEARCH will determine atmospheric properties such as cloud coverage, surface pressure and atmospheric composition, and may also be capable of identifying basic surface features. To resolve a planet with a semi major axis of down to 1.4AU and 30pc distant SEARCH will have a mirror system consisting of two segments, with elliptical rim, cut out of a parabolic mirror. This will yield an effective diameter of 9 meters along one axis. A phase mask coronagraph along with an integral spectrograph will be used to overcome the contrast ratio of star to planet light. Such a mission would provide invaluable data on the diversity present in extrasolar planetary systems and much more could be learned from the similarities and differences compared to our own Solar System. This would allow our theories of planetary formation, atmospheric accretion and evolution to be tested, and our understanding of regions such as the outer limit of the Habitable Zone to be further improved.Comment: 23 pages, accepted for publication in Experimental Astronom

A Map of Dielectric Heterogeneity in a Membrane Protein: the Hetero-Oligomeric Cytochrome b 6 f Complex

The cytochrome b6f complex, a member of the cytochrome bc family that mediates energy transduction in photosynthetic and respiratory membranes, is a hetero-oligomeric complex that utilizes two pairs of b-hemes in a symmetric dimer to accomplish trans-membrane electron transfer, quinone oxidation–reduction, and generation of a proton electrochemical potential. Analysis of electron storage in this pathway, utilizing simultaneous measurement of heme reduction, and of circular dichroism (CD) spectra, to assay heme–heme interactions, implies a heterogeneous distribution of the dielectric constants that mediate electrostatic interactions between the four hemes in the complex. Crystallographic information was used to determine the identity of the interacting hemes. The Soret band CD signal is dominated by excitonic interaction between the intramonomer b-hemes, bn and bp, on the electrochemically negative and positive sides of the complex. Kinetic data imply that the most probable pathway for transfer of the two electrons needed for quinone oxidation–reduction utilizes this intramonomer heme pair, contradicting the expectation based on heme redox potentials and thermodynamics, that the two higher potential hemes bn on different monomers would be preferentially reduced. Energetically preferred intramonomer electron storage of electrons on the intramonomer b-hemes is found to require heterogeneity of interheme dielectric constants. Relative to the medium separating the two higher potential hemes bn, a relatively large dielectric constant must exist between the intramonomer b-hemes, allowing a smaller electrostatic repulsion between the reduced hemes. Heterogeneity of dielectric constants is an additional structure–function parameter of membrane protein complexes

The bc 1 complexes of Rhodobacter sphaeroides and Rhodobacter capsulatus

Photosynthetic bacteria offer excellent experimental opportunities to explore both the structure and function of the ubiquinol-cytochrome c oxidoreductase ( bc 1 complex). In both Rhodobacter sphaeroides and Rhodobacter capsulatus , the bc 1 complex functions in both the aerobic respiratory chain and as an essential component of the photosynthetic electron transport chain. Because the bc 1 complex in these organisms can be functionally coupled to the photosynthetic reaction center, flash photolysis can be used to study electron flow through the enzyme and to examine the effects of various amino acid substitutions. During the past several years, numerous mutations have been generated in the cytochrome b subunit, in the Rieske iron-sulfur subunit, and in the cytochrome c 1 subunit. Both site-directed and random mutagenesis procedures have been utilized. Studies of these mutations have identified amino acid residues that are metal ligands, as well as those residues that are at or near either the quinol oxidase (Q o ) site or the quinol reductase (Q i ) site. The postulate that these two Q-sites are located on opposite sides of the membrane is supported by these studies. Current research is directed at exploring the details of the catalytic mechanism, the nature of the subunit interactions, and the assembly of this enzyme.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44795/1/10863_2004_Article_BF00762582.pd

Identifying Efficiency Degrading Faults in Split Air Conditioning Systems

Studies estimate that as much as 50% of packaged air conditioning systems operate in faulty conditions that degrade system efficiency. Common faults include: under- and over-charged systems (too much or too little refrigerant), faulty expansions valves (stuck valves, valve hunting, poorly tuned valve controllers), and fouled evaporators and condensers. Furthermore, air conditioning systems can often be adjusted to improve efficiency while continuing to meet cooling loads (adjusting system pressures, decreasing superheat setpoints). This study presents the design of a low cost device that can non-invasively measure system operating conditions, diagnose faults, estimate potential energy savings, and provide recommendations on how the system should be adjusted or repaired. Using eight external temperature measurements, the device potentially can detect and diagnose up to ten faults commonly found in HVAC systems. Steady state temperatures are compared to threshold values obtained from literature and HVAC manufacturers to detect and determine the severity of faults and subsequent reductions in coefficient of performance. Preliminary tests reveal the potential for the device to detect and diagnose common efficiency-degrading faults in HVAC systems