A Population-Based Study of Pregnancy and Delivery Characteristics Among Women with Vulvodynia

Introduction: To examine pregnancy and delivery characteristics of women with and without vulvodynia. Methods: The authors analyzed 227 vulvodynia cases that were less than 45 years old at pain onset; controls were age matched 1:1 to cases and had no history of vulvar pain. Pregnancy and delivery events were assessed after age at first vulvar pain onset (the reference age) in cases and a matched age in controls. Results: The authors observed no significant difference between cases and controls in achieving pregnancy after reference age. Also, no difference in pregnancy outcome was observed between cases and controls (P = 0.87). There was an indication that cases were more likely to receive a Cesarean section delivery (P = 0.07). In addition, 37.1% of cases who had vaginal delivery versus 11.3% of controls (P < 0.01) reported pain at 2 months postpartum. Comparing only women with vulvodynia, women who had intermittent pain versus constant pain were more than twice as likely to have a pregnancy (adjusted odds ratio 2.26, 95% CI 1.10–4.60). Conclusions: Women with vulvodynia may be as likely as other women to carry their pregnancy to birth; however, they may experience higher rates of Cesarean section delivery and could reflect a selection towards those women with vulvodynia who have inconsistent pain

Experimental and numerical investigations of sliding wear behaviour of an Fe-based Alloy for PWR Wear Resistance Applications

The excellent wear and corrosion resistance of Co-based alloys make them desirable for tribological applications in the nuclear industry. However, neutron activation of the Co-based alloys leads to significant occupational radiation doses. An alternative Fe-based alloy called RR2450 was developed by Rolls-Royce plc to replace these alloys. This paper presents the first comprehensive study evaluating the sliding wear resistance of RR2450 alloy in representative PWR conditions. The sliding counterface of RR2450 balls was a Co-based alloy, Haynes 25 discs. Four tests were performed at temperatures up to 80 °C, and 12 tests were performed up to 200 °C. Results showed wear performance of RR2450 balls degraded at higher loads and temperatures, with temperature having a significant role. Microstructural investigation revealed voids and hard silicide phases, negatively impacting wear resistance. Nonetheless, the wear performance of RR2450 was similar to a Co-based alloy, a=Stellite 20, at nuclear reactor conditions. Two wear tests with uneven wear tracks were selected for 3D finite element analysis. The wear simulation procedure is based on Archard’s wear equation and is implemented in a commercial FE package, ABAQUS. The FEA method was used to capture the wear on both surfaces, and was shown to predict nominal wear profiles. These comparisons with experiments show that the FEA results can provide representative wear profiles when wear depths and widths are asymmetrical and irregular

Sliding wear analysis of cobalt based alloys in nuclear reactor conditions

The study of the wear behaviour of cobalt based alloys in nuclear reactor environmental conditions is the focus of this work. The alloys are used in components within reactors due to their excellent wear and corrosion resistance and their high hardness in the high pressure and temperature water facing environment. In the nuclear reactor core, cobalt is irradiated producing a highly penetrative gamma emitting isotope, cobalt 60 from stable cobalt 59. Wear of the cobalt alloys, producing wear debris, exacerbates this problem as it may be transported and deposited at various locations throughout the primary loop increasing the potential of radiation exposure. Removing this problem will require the removal of cobalt from the system. In order for suitable replacement materials to be identified, a better understanding of the behaviour of these alloys in the prototypical working conditions must be obtained. This work focuses on two cobalt based alloys used in the ball and race components of rolling element bearings in the reactor core, Stellite 20 and Haynes 25, respectively. The sliding wear behaviour of the alloys in an environment designed to replicate reactor conditions is examined using a bespoke pin on disc tribometer. Wear measurement and microstructural and compositional analysis of the samples tested over a range of conditions are presented and discussed. Concurrent to the experimental work is the development of a wear prediction model using a semi analytical method. The model employs Archard’s wear law as the method of predicting wear using data obtained through experimentation. The accuracy of the semi analytical model is limited however it does give a good estimation for maximum wear depth of the test specimens

Scenario of Accelerating Universe from the Phenomenological \Lambda- Models

Dark matter, the major component of the matter content of the Universe, played a significant role at early stages during structure formation. But at present the Universe is dark energy dominated as well as accelerating. Here, the presence of dark energy has been established by including a time-dependent $\Lambda$ term in the Einstein's field equations. This model is compatible with the idea of an accelerating Universe so far as the value of the deceleration parameter is concerned. Possibility of a change in sign of the deceleration parameter is also discussed. The impact of considering the speed of light as variable in the field equations has also been investigated by using a well known time-dependent $\Lambda$ model.Comment: Latex, 9 pages, Major change

Bioavailability of iodine in the UK-Peak District environment and its human bioaccessibility: an assessment of the causes of historical goitre in this area

Iodine is an essential micronutrient for human health. Its deficiency causes a number of functional and developmental abnormalities such as goitre. The limestone region of Derbyshire, UK was goitre-endemic until it declined from the 1930s and the reason for this has escaped a conclusive explanation. The present study investigates the cause(s) of goitre in the UK-Peak District area through an assessment of iodine in terms of its environmental mobility, bioavailability, uptake into the food chain and human bioaccessibility. The goitre-endemic limestone area is compared with the background millstone grit area of the UK-Peak District. The findings of this study show that ‘total’ environmental iodine is not linked to goitre in the limestone area, but the governing factors include iodine mobility, bioavailability and bioaccessibility. Compared with the millstone grit area, higher soil pH and calcium content of the limestone area restrict iodine mobility in this area, also soil organic carbon in the limestone area is influential in binding the iodine to the soil. Higher calcium content in the limestone area is an important factor in terms of strongly fixing the iodine to the soil. Higher iodine bioaccessibility in the millstone grit than the limestone area suggests that its oral bioaccessibility is restricted in the limestone area. Iodine taken up by plant roots is transported freely into the aerial plant parts in the millstone grit area unlike the limestone area, thus providing higher iodine into the human food chain in the millstone grit area through grazing animals unlike the goitre-prevalent limestone area

Transposon-mediated BAC transgenesis in human ES cells

Transgenesis is a cornerstone of molecular biology. The ability to integrate a specifically engineered piece of DNA into the genome of a living system is fundamental to our efforts to understand life and exploit its implications for medicine, nanotechnology and bioprospecting. However, transgenesis has been hampered by position effects and multi-copy integration problems, which are mainly due to the use of small, plasmid-based transgenes. Large transgenes based on native genomic regions cloned into bacterial artificial chromosomes (BACs) circumvent these problems but are prone to fragmentation. Herein, we report that contrary to widely held notions, large BAC-sized constructs do not prohibit transposition. We also report the first reliable method for BAC transgenesis in human embryonic stem cells (hESCs). The PiggyBac or Sleeping Beauty transposon inverted repeats were integrated into BAC vectors by recombineering, followed by co-lipofection with the corresponding transposase in hESCs to generate robust fluorescent protein reporter lines for OCT4, NANOG, GATA4 and PAX6. BAC transposition delivers several advantages, including increased frequencies of single-copy, full-length integration, which will be useful in all transgenic systems but especially in difficult venues like hESCs

Optimal Control of Nonlinear Switched Systems: Computational Methods and Applications

A switched system is a dynamic system that operates by switching between different subsystems or modes. Such systems exhibit both continuous and discrete characteristics—a dual nature that makes designing effective control policies a challenging task. The purpose of this paper is to review some of the latest computational techniques for generating optimal control laws for switched systems with nonlinear dynamics and continuous inequality constraints. We discuss computational strategiesfor optimizing both the times at which a switched system switches from one mode to another (the so-called switching times) and the sequence in which a switched system operates its various possible modes (the so-called switching sequence). These strategies involve novel combinations of the control parameterization method, the timescaling transformation, and bilevel programming and binary relaxation techniques. We conclude the paper by discussing a number of switched system optimal control models arising in practical applications

NANOG Reporter Cell Lines Generated by Gene Targeting in Human Embryonic Stem Cells

Background: Pluripotency and self-renewal of human embryonic stem cells (hESCs) is mediated by a complex interplay between extra- and intracellular signaling pathways, which regulate the expression of pluripotency-specific transcription factors. The homeodomain transcription factor NANOG plays a central role in maintaining hESC pluripotency, but the precise role and regulation of NANOG are not well defined. Methodology/Principal Findings: To facilitate the study of NANOG expression and regulation in viable hESC cultures, we generated fluorescent NANOG reporter cell lines by gene targeting in hESCs. In these reporter lines, the fluorescent reporter gene was co-expressed with endogenous NANOG and responded to experimental induction or repression of the NANOG promoter with appropriate changes in expression levels. Furthermore, NANOG reporter lines facilitated the separation of hESC populations based on NANOG expression levels and their subsequent characterization. Gene expression arrays on isolated hESC subpopulations revealed genes with differential expression in NANOG high and NANOG low hESCs, providing candidates for NANOG downstream targets hESCs. Conclusion/Significance: The newly derived NANOG reporter hESC lines present novel tools to visualize NANOG expression in viable hESCs. In future applications, these reporter lines can be used to elucidate the function and regulation of NANO

A review of the changing culture and social context relating to forensic facial depiction of the dead

The recognition of a decedent by a family member is commonplace in forensic investigation and is often employed as identity confirmation. However, it is recognised that misidentification from facial recognition is also common and faces of the dead may be extremely difficult to recognise due to decomposition or external damage, and even immediate post-mortem changes may be significant enough to confuse an observer. The depiction of faces of the dead can be a useful tool for promoting recognition leading to identification and post-mortem facial depiction is described as the interpretation of human remains in order to suggest the living appearance of an individual. This paper provides an historical context relating to the changing view of society to the presentation and publication of post-mortem facial depictions and discusses the current ethical, practical and academic challenges associated with these images