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‘Mothering Illegitimate Children in Late Eighteenth-Century England’
No full textThis article examines the care of elite illegitimate children by birth mothers and stepmothers in late eighteenth-century England. Focusing on the letters and financial records of elite families extends a previous historiographical emphasis on illegitimacy as a facet of poverty and shows that attitudes towards illegitimate children and their multiple mothers were heavily mediated by economic inequality, class-based ideals of gender and family, and the absent hand of the poor law. The experiences of birth mothers and stepmothers can be compared with their presentation in contemporary novels, suggesting that women drew on cultural scripts to justify their actions. Single birth mothers were encouraged to be physically absent, but they also manipulated mainstream ideals to construct facets of a positive maternal identity. Stepmothers, meanwhile, included illegitimate children in affective and instrumental ideals of family. Stepmothering could be a positive aspect of elite feminine identity, construing such women as benevolent saviours of the motherless and as matriarchs of successful dynasties. The adoption of illegitimate children was not invariably damaging to female reputation. The example of caring for illegitimate children thus reveals the highly unequal and sometimes coercive aspects of the shared labour of mothering
Molecular Mobility of a Polymer of Intrinsic Microporosity Revealed by Quasielastic Neutron Scattering
No full textQuasielastic neutron scattering by employing a combination of time-of-flight and backscattering techniques is carried out to explore the molecular mobility of a polymer of intrinsic microporosity (PIM-1) at microscopic time scales in comparison with a high-performance polyimide. Molecular fluctuations can change the structure of the temporary network of micropores and open or close pathways for gas molecules. Therefore, the investigation might help to understand the selectivity of PIMs in gas separation processes. The performed neutron scattering experiments provide evidence for a low-temperature relaxation process, which was assigned to methyl group rotation. This methyl group rotation was analyzed in terms of jump diffusion in a three-fold potential. The analysis results in a fraction of methyl groups which are immobilized. For PIM-1 it was found that the fraction of immobilized methyl groups decreases with increasing temperature up to 350 K. At higher temperatures the number of immobilized methyl group increases gain due to an underlying relaxation process. This motional process on a somewhat larger length scale might lead to a reversible structural rearrangement which partially hinders the strongly localized methyl group rotation. In addition, it was found that the activation energy for the methyl group rotation for PIM-1 and the polyimide is significantly higher than for conventional polymers
Study of eclipses for Redback pulsar J1227−4853
No full textWe present a multi-frequency study of eclipse properties of a transitional redback millisecond pulsar J1227−4853 discovered in 2014 with the GMRT. Emission from this pulsar is eclipsed at 607 MHz for about 37% of its orbit around the superior conjunction. We observe eclipse ingress and egress transition which last 12% and 15% of its orbit respectively, resulting in only 36% of the orbit being unaffected by eclipsing material. We report an excess dispersion measure (DM) at eclipse boundaries of 0.079(3) pc cm−3 and the corresponding electron column density (Ne) is 24.4(8) x 1016 cm−2. Simultaneous timing and imaging studies suggests that the eclipses in J1227−4853 are not caused by temporal smearing due to excess dispersion and scattering but could be caused by removal of pulsar flux due to cyclotron absorption of the pulsed signal by intra-binary material constraining the companion’s magnetic field. Additionally, near inferior conjunction at orbital phase 0.71 and 0.82 the pulsed emission is significantly delayed which is associated with a fading of the pulsed and continuum flux densities. At orbital phase ∼0.82, we measure a change in DM of 0.035(3) pc cm−3 and Ne of 10.8(8) x 1016 cm−2 associated with a dimming of up to ∼30% of the peak flux density. Such flux fading around a fixed orbital phase is not reported for other eclipsing binaries. Moreover, this event around inferior conjunction could be caused by absorption of pulsed signal by fragmented blobs of plasma generated from mass loss through the L2 Lagrangian point
Chemical Trends in the Lattice Thermal Conductivity of Li(Ni, Mn, Co)O2 (NMC) Battery Cathodes
No full textOptimal periodicity searching: Revisiting the Fast Folding Algorithm for large-scale pulsar surveys
No full textThe Fast Folding Algorithm (FFA) is a phase-coherent search technique for periodic signals. It has rarely been used in radio pulsar searches, having been historically supplanted by the less computationally expensive Fast Fourier Transform (FFT) with incoherent harmonic summing (IHS). Here we derive from first principles that an FFA search closely approaches the theoretical optimum sensitivity to all periodic signals; it is analytically shown to be significantly more sensitive than the standard FFT+IHS method, regardless of pulse period and duty cycle. A portion of the pulsar phase space has thus been systematically under-explored for decades; pulsar surveys aiming to fully sample the pulsar population should include an FFA search as part of their data analysis.We have developed an FFA software package, riptide, fast enough to process radio observations on a large scale; riptide has already discovered sources undetectable using existing FFT+IHS implementations. Our sensitivity comparison between search techniques also shows that a more realistic radiometer equation is needed, which includes an additional term: the search efficiency. We derive the theoretical efficiencies of both the FFA and the FFT+IHS methods and discuss how excluding this term has consequences for pulsar population synthesis studies
Preventing Ovarian Cancer through early Excision of Tubes and late Ovarian Removal (PROTECTOR): protocol for a prospective non-randomised multicentre trial
No full textBackground Risk-reducing-salpingo-oophorectomy is gold standard for preventing tubo-ovarian-cancer in women at increased risk. However when performed in premenopausal women, it results in premature-menopause and associated detrimental health consequences. This, along with acceptance of the central role of the fallopian-tube in etiopathogenesis of high-grade serous carcinoma, by far the most common type of tubo-ovarian-cancer, has led to risk-reducing early-salpingectomy with delayed-oophorectomy being proposed as a two-step surgical alternative for pre-menopausal women declining/delaying oophorectomy. Primary-objective To evaluate impact on sexual function of risk-reducing-early-salpingectomy, within a two-step risk-reducing early-salpingectomy with delayed-oophorectomy tubo-ovarian-cancer prevention strategy in premenopausal women at increased risk of tubo-ovarian-cancer. Hypothesis Risk-reducing-early-salpingectomy is non-inferior for sexual and endocrine function compared to controls; risk-reducing-early-salpingectomy is superior for sexual/endocrine function, non-inferior in terms of quality-of-life, and equivalent in satisfaction compared to the standard risk-reducing-salpingo-oophorectomy. Trial-design Multi-centre, observational cohort trial with three arms: risk-reducing-early-salpingectomy with delayed-oophorectomy; risk-reducing-salpingo-oophorectomy; controls (no surgery). Consenting individuals undergo an ultrasound, serum CA125 and FSH and provide information on medical history, family-history, quality-of-life, sexual function, cancer worry, psychological well-being and satisfaction/regret. Questionnaire follow-up takes place annually for three years. Risk-reducing early-salpingectomy women can undergo delayed-oophorectomy at a later date of their choosing or definitely by menopause. Major inclusion/exclusion criteria Inclusion-criteria: Premenopausal; >30 years; at increased risk of tubo-ovarian-cancer (mutation carriers or on the basis of a strong family-history); completed their family (for surgical arms). Exclusion-criteria: Postmenopausal; previous bilateral salpingectomy or bilateral oophorectomy; pregnancy; previous tubal/ovarian/peritoneal malignancy; <12 months post cancer treatment; clinical suspicion of tubal/ovarian cancer at baseline. Primary endpoint Sexual-function measured by validated questionnaires. Sample size 1000 (333 per-arm). Estimated dates for completing accrual and presenting results It is estimated recruitment will be completed by 2023 and results published by 2027. Trial registration ISRCTN registry: 25173360 (https://doi.org/10.1186/ISRCTN25173360)
Simulations of the MilkyWay’s central molecular zone - I. Gas dynamics
No full textWe use hydrodynamical simulations to study the MilkyWay’s central molecular zone (CMZ), i.e. the star-forming nuclear ring at Galactocentric radii R . 200 pc. The simulations comprise the gas flow in a Milky Way barred potential out to R = 5 kpc, which is necessary in order to capture the large-scale environment in which the CMZ is embedded and with which it is strongly interacting through the bar-driven inflow. The simulations also include a nonequilibrium time-dependent chemical network, gas self-gravity, and a sub-grid model for starformation and supernova feedback, all while reaching sub-parsec resolution in the densest regions. Our main findings are as follows: (1) The distinction between inner (R . 120 pc) and outer (120 . R . 450 pc) CMZ that is sometimes proposed in the literature is unnecessary. Instead, the CMZ is best described as single structure, namely a star-forming ring with outer radius R ' 200 pc which is interacting directly with the dust lanes that mediate the bar-driveninflow. (2) This accretion can induce a significant tilt of the CMZ out of the plane. A tilted CMZ might provide an alternative explanation to the ¥-shaped structure identified in Herschel data by Molinari et al. 2011. (3) The bar in our simulation efficiently drives an inflow from the Galactic disc (R ' 3 kpc) down to the CMZ (R ' 200 pc) of the order of 1M yr&#x100000;1, consistent with observational determinations. (4) Self-gravity and supernovae feedback can drive an inflow from the CMZ inwards towards the circumnuclear disc of the order of 0:03M yr&#x100000;1.(5) We give a new interpretation for the 3D placement of the 20 and 50 km s&#x100000;1 clouds, according to which they are close (R . 30 pc) to the Galactic centre, but are also connected to the larger-scale streams at R & 100 pc
How does Transition to Secondary School Influence Home, School and Community Play?
No full textAim: This study gathered views of 10 to 12-years-old pupils about their play experiences before and after transition to secondary school, comparing access to their right to play.Method: A multiple-case study design was used to gather views of six Year 6 primary pupils and six Year 7 secondary pupils living in the same community in the United Kingdom (UK). Six workshops, including a focus group, were conducted with each year group. Findings: Qualitative data from both focus groups were analysed thematically, individually and across year groups. Findings indicated that temporal, spatial and psychological factors affected both Year 6 and Year 7 pupils’ play access. Year 6 pupils were more satisfied with their play opportunities and reported more time to play. Limitations: The small-scale size of this study limits drawing conclusions. Data were collected in the summer term and therefore the weather and point in the school year may have been influential.Conclusions: Findings suggested that, for the pupils involved, play opportunities appeared to decrease upon transition to secondary school. It is therefore important that barriers to play across age groups are considered and addressed, to ensure that all children can realise their right to play. Educational psychologists (EPs) can raise awareness of the benefits of play and the potential impact of limited play opportunities for older children. <br/
Loneliness and Social Relationships among 14-Year-Olds in the UK: Findings from the Millennium Cohort Study
No full textIn the current study, data collected from wave six of the Millennium Cohort Study (MCS, n =11,872), a nationally representative sample survey of youth aged 14 years in the UK, are used to examine the prevalence of loneliness among this age group, investigate the feelings associated with the experience of loneliness among youth, explore the risk factors for loneliness among young people, and learn how they coped with loneliness. Given recent findings that youth are vulnerable to loneliness, the study assesses the prevalence of loneliness among adolescents across some important socio-demographic characteristics, such as nation of residence, gender, and ethnicity. We also identify the kinds of social experiences that accompany loneliness during adolescence, exploring friendship, relations with parents, social support, and bullying. Our key finding is that, in addition to the absence of desired social relationships, which has been typically identified as the ultimate source of loneliness, the presence of undesired and even harmful social relationships is a major source of loneliness. This study uniquely brings together psychological and sociological perspectives to understand the experience of youth loneliness
The effect of Al on the formation and stability of a bcc - B2 microstructure in a refractory metal high entropy superalloy system
No full textThe development of Refractory Metal High Entropy Superalloys has received great interest due to their potential to replace Ni-based superalloys in high temperature structural applications. The formation of a two-phase nanoscale microstructure, comprising bcc and ordered B2 phases, is thought to be fundamentally linked to the presence of Al. As such, determining the influence of Al concentration on the microstructural formation and thermal stability of these novel materials is critical for future alloy development. To elucidate this effect, the microstructural evolution of a systematic series of alloys from the Ti-Ta-Zr-Alx system have been studied following homogenisation and long term exposures at 1100, 900 and 700˚C. Nanoscale cuboidal morphologies were observed in all alloys, but the onset of ordering was only observed when the bulk Al content was > 5 at.%. These results indicated that a common formation mechanism, thought to be spinodal decomposition, occurred prior to any B2 ordering. The results also showed that the B2 phase was only stable to relatively moderate temperatures, < 900˚C, eliminating order hardening as a high temperature strengthening mechanism. In addition, for the alloy with the greatest Al content, deleterious intragranular Al-Zr-rich intermetallics were observed following the long duration thermal exposures