To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Updated by a team of internationally renowned experts, this book gives a thorough overview of fetal pathophysiology and an evidence base for in utero: both medical (non-invasive) and surgical treatments. Many topics are expanded to cover recent advances, including: stem cell transplantation; tissue scaffolding; minimally invasive approaches to 'open fetal surgery'; the etiology, prevention and treatment of preterm birth and PROM; the genetic etiologies of fetal disease; and gene therapy. In addition, there are in-depth discussions as to the role of open fetal myelomeningocele repair and several fetoscopic approaches to therapy. The international editors have added important new chapters on reducing stillbirth and prenatal counselling. This book is an invaluable reference guide to the latest fetal therapy options, and an essential, in-depth study book for maternal-fetal and neonatology specialists.
The spread of the Zika virus (ZIKV) in the Americas led to large outbreaks across the region and most of the Southern hemisphere. Of greatest concern were complications following acute infection during pregnancy. At the beginning of the outbreak, the risk to unborn babies and their clinical presentation was unclear. This report describes the methods and results of the UK surveillance response to assess the risk of ZIKV to children born to returning travellers. Established surveillance systems operating within the UK – the paediatric and obstetric surveillance units for rare diseases, and national laboratory monitoring – enabled rapid assessment of this emerging public health threat. A combined total of 11 women experiencing adverse pregnancy outcomes after possible ZIKV exposure were reported by the three surveillance systems; five miscarriages, two intrauterine deaths and four children with clinical presentations potentially associated with ZIKV infection. Sixteen women were diagnosed with ZIKV during pregnancy in the UK. Amongst the offspring of these women, there was unequivocal laboratory evidence of infection in only one child. In the UK, the number and risk of congenital ZIKV infection for travellers returning from ZIKV-affected countries is very small.
In 2008, for the first time in the history of this country, a black woman became First Lady of the United States. During Barack Obama's presidency, Michelle Obama was ever present in the public eye for her advocacy on issues related to health, military families, education, and for promoting the interests of women and girls. This article contributes to ongoing scholarly discourse, as well as extensive media coverage and analysis, regarding Obama's role as wife and first lady by critically examining how the particular model of motherhood she embraced and exhibited, a model firmly rooted in the black American community, was designed to challenge negative stereotypes of black women, maternity, and families. We address the following questions in this work: How did Obama's identity as a black woman influence the policies she championed as first lady? Does Obama's mothering relate to stereotypes of black mothers and help (re)define black motherhood, and if so, how? What does it mean to be a black mater gentis or mother of the nation? Drawing on her speeches and policy initiatives, we reveal how Michelle Obama defied dominant and oppressive stereotypes of black women and mothers while simultaneously (re)defining black womanhood and motherhood for the nation.
Heart rate variability (HRV) is a proxy measure of autonomic function and can be used as an indicator of swine stress. While traditional linear measures are used to distinguish between stressed and unstressed treatments, inclusion of nonlinear HRV measures that evaluate data structure and organization shows promise for improving HRV interpretation. The objective of this study was to evaluate the inclusion of nonlinear HRV measures in response to an acute heat episode. Twenty 12- to 14-week-old growing pigs were individually housed for 7 days and acclimated to thermoneutral conditions (20.35°C ± 0.01°C; 67.6% ± 0.2% RH) before undergoing one of the two treatments: (1) thermoneutral control (TN; n = 10 pigs) or (2) acute heat stress (HS; n = 10 pigs; 32.6°C ± 0.1°C; 26.2% ± 0.1% RH). In Phase 1 of the experimental procedure (P1; 60 min), pigs underwent a baseline HRV measurement period in thermoneutral conditions before treatment [Phase 2; P2; 60 min once gastrointestinal temperature (Tg) reached 40.6°C], where HS pigs were exposed to heated conditions and TN pigs remained in thermoneutral conditions. After P2, all pigs were moved back to thermoneutral conditions (Phase 3; P3; 60 min). During each phase, Tg data were collected every 5 min and behavioural data were collected to evaluate the amount of time each pig spent in an active posture. Additionally, linear (time and frequency domain) and nonlinear [sample entropy (SampEn), de-trended fluctuation analysis, percentage recurrence, percentage determinism (%DET), mean diagonal line length in a recurrence plot] HRV measures were quantified. Heat stressed pigs exhibited greater Tg (P = 0.002) and spent less time in an active posture compared to TN pigs during P2 (P = 0.0003). Additionally, low frequency to high frequency ratio was greater in HS pigs during P3 compared to TN pigs (P = 0.02). SampEn was reduced in HS pigs during P2 (P = 0.01) and P3 (P = 0.03) compared to TN pigs. Heat stressed pigs exhibited greater %DET during P3 (P = 0.03) and tended to have greater %DET (P = 0.09) during P2 than TN pigs. No differences between treatments were detected for the remaining HRV measures. In conclusion, linear HRV measures were largely unchanged during P2. However, changes to SampEn and %DET suggest increased heat stress as a result of the acute heat episode. Future work should continue to evaluate the benefits of including nonlinear HRV measures in HRV analysis of swine heat stress.
Powerful synergies between phosphonate, zinc oxide, and acrylamido-tert-butyl-sulfonate (ATBS) copolymer chemical additives render superior performance in a high-temperature retarder system for oil well grade Portland cement. The phosphonate retarder and ATBS-based retarders establish a two-tiered strength development where amorphous C-S-H converts to crystalline dicalcium silicate hydrate (C2SH) in the first (low compressive strength) tier prior to the reaction of Portlandite with quartz. The three additive retarder system can be tuned with nanosilica to eliminate the two-tiered strength development effect leading to a smooth transition from the cement in the slurry form directly to its highest compressive strength.
Background: Cervical sponylotic myelopathy (CSM) may present with neck and arm pain. This study investiagtes the change in neck/arm pain post-operatively in CSM. Methods: This ambispective study llocated 402 patients through the Canadian Spine Outcomes and Research Network. Outcome measures were the visual analogue scales for neck and arm pain (VAS-NP and VAS-AP) and the neck disability index (NDI). The thresholds for minimum clinically important differences (MCIDs) for VAS-NP and VAS-AP were determined to be 2.6 and 4.1. Results: VAS-NP improved from mean of 5.6±2.9 to 3.8±2.7 at 12 months (P<0.001). VAS-AP improved from 5.8±2.9 to 3.5±3.0 at 12 months (P<0.001). The MCIDs for VAS-NP and VAS-AP were also reached at 12 months. Based on the NDI, patients were grouped into those with mild pain/no pain (33%) versus moderate/severe pain (67%). At 3 months, a significantly high proportion of patients with moderate/severe pain (45.8%) demonstrated an improvement into mild/no pain, whereas 27.2% with mild/no pain demonstrated worsening into moderate/severe pain (P <0.001). At 12 months, 17.4% with mild/no pain experienced worsening of their NDI (P<0.001). Conclusions: This study suggests that neck and arm pain responds to surgical decompression in patients with CSM and reaches the MCIDs for VAS-AP and VAS-NP at 12 months.
Unlike most bird species, individual kingfisher species (Aves: Alcedinidae) are typically parasitized by only a single genus of louse (Alcedoffula, Alcedoecus, or Emersoniella). These louse genera are typically specific to a particular kingfisher subfamily. Specifically, Alcedoecus and Emersoniella parasitize Halcyoninae, whereas Alcedoffula parasitizes Alcedininae and Cerylinae. Although Emersoniella is geographically restricted to the Indo-Pacific region, Alcedoecus and Alcedoffula are geographically widespread. We used DNA sequences from two genes, the mitochondrial COI and nuclear EF-1α genes, to infer phylogenies for the two geographically widespread genera of kingfisher lice, Alcedoffula and Alcedoecus. These phylogenies included 47 kingfisher lice sampled from 11 of the 19 currently recognized genera of kingfishers. We compared louse phylogenies to host phylogenies to reconstruct their cophylogenetic history. Two distinct clades occur within Alcedoffula, one that infests Alcedininae and a second that infests Cerylinae. All species of Alcedoecus were found only on host species of the subfamily Halcyoninae. Cophylogenetic analysis indicated that Alcedoecus, as well as the clade of Alcedoffula occurring on Alcedininae, do not show evidence of cospeciation. In contrast, the clade of Alcedoffula occurring on Cerylinae showed strong evidence of cospeciation.
This paper documents autonomous multi-floor stairwell ascent by a legged robot. This is made possible through empirically deployed sequential composition of several reactive controllers, with perceptually triggered transitions. This composition relies on simplified assumptions regarding the robot’s sensory capabilities, its level of mobility, and the environment it operates in. The discrepancies between these assumptions and the physical reality are capably handled by the intrinsic motor competence of the robot. This behavior is implemented on the legged RHex platform and experiments spanning 10 different stairwells with various challenges are conducted.
Disease surveillance in wildlife populations presents a logistical challenge, yet is critical in gaining a deeper understanding of the presence and impact of wildlife pathogens. Erinaceus coronavirus (EriCoV), a clade C Betacoronavirus, was first described in Western European hedgehogs (Erinaceus europaeus) in Germany. Here, our objective was to determine whether EriCoV is present, and if it is associated with disease, in Great Britain (GB). An EriCoV-specific BRYT-Green® real-time reverse transcription PCR assay was used to test 351 samples of faeces or distal large intestinal tract contents collected from casualty or dead hedgehogs from a wide area across GB. Viral RNA was detected in 10.8% (38) samples; however, the virus was not detected in any of the 61 samples tested from Scotland. The full genome sequence of the British EriCoV strain was determined using next generation sequencing; it shared 94% identity with a German EriCoV sequence. Multivariate statistical models using hedgehog case history data, faecal specimen descriptions and post-mortem examination findings found no significant associations indicative of disease associated with EriCoV in hedgehogs. These findings indicate that the Western European hedgehog is a reservoir host of EriCoV in the absence of apparent disease.
The X-ray diffraction patterns from fibrous polymers are generally characterized by a small number of relatively broad overlapping peaks often overlaid with a diffuse halo. Single fibres give the same pattern as a parallel bundle of fibres, so that the pattern is equivalent to the rotation pattern of a single crystal. Despite the inherent difficulty of insufficient well-defined reflections, all commercially useful fibres have been indexed, starting with cellulose, through nylon 66 and polyester, to the more recent fibres, such as Nomex and Kevlar. Only the structural complexities of the natural fibres of keratin (wool and hair) remain to be fully determined.
Many sophisticated computations have been carried out to refine unit-cell constants; unfortunately, much of this work is of doubtful value to those interested in fibre characterisation. Fibres are semicrystalline materials and their molecules are insufficiently well ordered for precision calculations of atomic positions. Indeed, there can be significant error involved in evaluating unit-cell constants from overlapping peaks, unless precise profile resolution is carried out.
The affect of several aberrations on the figures of merit, FOM, used in the identification analysis of diffraction patterns has been examined by generating simulated diffraction traces with mathematically induced errors. Patterns of mixtures with random 20 shifts, intensity variations, and profile broadening were generated for analysis by MATCHDB, and the behavior of three FOMs during the search step was followed. The results have shown that the angle errors are the most serious in degrading the potential for identification of the phases in the mixtures. Intensity errors cause some degradation on the results. Broadening has little affect when using whole-pattern matching methods.
A file of digitized diffraction traces for clay minerals has been developed as a test for the usefulness of such traces in the analysis of clays and clay deposits. The kaolin, smectite, mica clay and chlorite groups are represented by patterns of the most common mineral species in the small crystallite size which is typical of their natural occurrences. Patterns are included for the oriented sample and for glycolated and heated samples when appropriate. This database may form a nucleus for an extensive collection of clay mineral traces in the same manner as the early Powder Diffraction File did for the modern PDE.
The use of whole-pattern matching techniques for phase identification provides increased confidence in the phases determined compared with d-I matching and enhances the potential for determining the existence of phases present in low concentrations. Reference patterns from a database of selected phases were compared with the experimental pattern obtained from an unknown, and the results were ranked using figures-of-merit designed to distinguish the best pattern matches. Several different figures-of-merit have been evaluated, all of which proved successful in recognizing the strongest phase but varied with respect to the other phases.
Low-concentration phases are revealed when the patterns of the more abundant phases are stripped from the experimental trace using the best-fit scaled reference traces. Pattern stripping is improved by pattern shifting and profile shape matching which are provided for in the matching program.
The former Deep Sea Drilling Project (DSDP) automated X-ray diffraction data collection and analysis system located at the Riverside campus of the University of California has been upgraded for use in the characterization of samples from natural hydrothermal systems by the addition of an interactive graphics terminal and the rewriting of the computer programs.
The system has the capability of collecting and interpreting patterns from 25-30 samples in one night's unattended operation. The computer's interpretation can be monitored and corrected easily. The pattern and the computed baseline are displayed with the peak locations and intensities, as predicted by the mineral standards file, and calculated mineral intensities superimposed. The system can display a pattern and accept and remember corrections to its interpretation in less than two minutes. The system can also organize and display the interpretations of a suite of samples in both tabular and graphical form.
The mineral identifications, minimum levels of detections and quantities calculated were tested using artificial mixtures of known composition and comparisons with other techniques and found to be adequate. As an example of the system's output, approximately 500 samples of cuttings from 12 boreholes drilled in the Salton Sea geothermal field in California have been run. The mineral modal analyses for samples from each well was produced in a diagrammatic format suitable for displaying on maps to show the three-dimensional distribution of mineral abundances.
The system gives adequate quality of analysis for the mapping of mineral abundances. The main benefit is the assumption of bookkeeping functions thus allowing the analyst to concentrate on the more difficult interpretation problems. The current drawback of the system is the difficulty in dealing with clays.
Quantitative X-ray powder diffraction using the complete digitized diffraction pattern has proved to be an effective approach to improving the accuracy of the analysis of complex mineral mixtures, provided representative reference patterns and accurate Reference Intensity Ratio (RIR) factors arc available for each component phase. However, chemical and structural variability of common rock-forming minerals may complicate the pattern fitting approach. A method has been developed which utilizes X-ray fluorescence chemistry of an unknown and realistic compositional ranges for component phases as constraints on the quantitative XRD analysis without significant compromise of the pattern fit. This unique approach no only yields accurate weight fractions, but also provides indications of the specific compositions of each phase present in the mixture.
In powder diffraction experiments involving mixtures of compounds, identification of each individual phase is complicated by the presence of other phases. The interpretation of such complex patterns is often very difficult, and much effort has gone into computational search-match algorithms which attempt to identify individual phases (Nichols, 1966; Johnson, 1977; Frevel, 1976). The success achieved by these programs and by manual search-match methods accounts for the fact that X-ray diffractionists have, in the past, not actively searched for other techniques that could be used to simplify such complex problems. In a recent work (Nichols & Johnson, 1980), a comparison was made of the search-match methodologies employed by several similar technologies (mass spectroscopy, fingerprint identification, X-ray diffraction etc.). A significant observation was made that only in the X-ray method was there so much emphasis on analysis of phases in their “as received” condition. In the other cases, emphasis was placed on the separation of phases before obtaining the spectra. A classical example is the GC-MS instrument which employs a gas chromatograph to separate phases before the mass spectrographic analysis is carried out on what are, by that time, essentially pure phases.