441 research outputs found

    The Lack of Childcare and its Impact in America

    Get PDF
    Child care is expensive. The average cost of child care in the United States can range from 9- 36% of a family’s income, depending on where they live. We are the only industrialized country that does not offer some kind paid family leave. For one of the richest countries in the world, child poverty rates have remained increasingly high in America. The lack of affordable child care has become a national crisis, with daycare costing more than in-state university tuition in half of the country. Lowering costs and providing better access to high quality childcare can significantly increase parents’ employment rates and incomes. In turn, the increase in income has the potential to improve children’s outcomes as well in terms of more educational opportunities later in life. A typical family paying for child care spends about 10% of their income but the challenge is especially acute for low-income families and single parents. In some states, a minimum wage worker simply would need to work more weeks than exist in a year to afford an average-priced day care. Quality child care is expensive and in many states it can cost more than college tuition. In California, the cost of a typical day-care center is now equal to almost half of the median income of a single parent

    Tuning the Dzyaloshinskii-Moriya Interaction in Pt/Co/MgO heterostructures through MgO thickness

    Get PDF
    The interfacial Dzyaloshinskii-Moriya interaction (DMI) in the ferromagnetic/heavy metal ultra-thin film structures , has attracted a lot of attention thanks to its capability to stabilize Neel-type domain walls (DWs) and magnetic skyrmions for the realization of non-volatile memory and logic devices. In this study, we demonstrate that magnetic properties in perpendicularly magnetized Ta/Pt/Co/MgO/Pt heterostructures, such as magnetization and DMI, can be significantly influenced through both the MgO and the Co ultrathin film thickness. By using a field-driven creep regime domain expansion technique, we find that non-monotonic tendencies of DMI field appear when changing the thickness of MgO and the MgO thickness corresponding to the largest DMI field varies as a function of the Co thicknesses. We interpret this efficient control of DMI as subtle changes of both Pt/Co and Co/MgO interfaces, which provide a method to investigate ultra-thin structures design to achieve skyrmion electronics.Comment: 18 pages, 11 figure

    Governance in the age of social machines: the web observatory

    Get PDF
    The World Wide Web has provided unprecedented access to information; as humans and machines increasingly interact with it they provide more and more data. The challenge is how to analyse and interpret this data within the context that it was created, and to present it in a way that both researchers and practitioners can more easily make sense of. The first step is to have access to open and interoperable data sets, which Governments around the world are increasingly subscribing to. But having ‘open’ data is just the beginning and does not necessarily lead to better decision making or policy development. This is because data do not provide the answers – they need to be analysed, interpreted and understood within the context of their creation, and the business imperative of the organisation using them. The major corporate entities, such as Google, Amazon, Microsoft, Apple and Facebook, have the capabilities to do this, but are driven by their own commercial imperatives, and their data are largely siloed and held within ‘walled gardens’ of information. All too often governments and non-profit groups lack these capabilities, and are driven by very different mandates. In addition they have far more complex community relationships, and must abide by regulatory constraints which dictate how they can use the data they hold. As such they struggle to maximise the value of this emerging ‘digital currency’ and are therefore largely beholden to commercial vendors. What has emerged is a public-private data ecosystem that has huge policy implications (including the twin challenges of privacy and security). Many within the public sector lack the skills to address these challenges because they lack the literacy required within the digital context. This project seeks to address some of these problems by bringing together a safe and secure Australian-based data platform (facilitating the sharing of data, analytics and visualisation) with policy analysis and governance expertise in order to create a collaborative working model of a ‘Government Web Observatory’. This neutral space, hosted by an Australian university, can serve as a powerful complement to existing Open Data initiatives in Australia, and enable research and education to combine to support the development of a more digitally literate public service. The project aims to explore where, and in which contexts, people, things, data and the Internet meet and result in evolving observable phenomena which can inform better government policy development and service delivery.&nbsp

    Signal identification with Kalman Filter towards background-free neutrinoless double beta decay searches in gaseous detectors

    Full text link
    Particle tracks and differential energy loss measured in high pressure gaseous detectors can be exploited for event identification in neutrinoless double beta decay~(0ÎœÎČÎČ0\nu \beta \beta) searches. We develop a new method based on Kalman Filter in a Bayesian formalism (KFB) to reconstruct meandering tracks of MeV-scale electrons. With simulation data, we compare the signal and background discrimination power of the KFB method assuming different detector granularities and energy resolutions. Typical background from 232^{232}Th and 238^{238}U decay chains can be suppressed by another order of magnitude than that in published literatures, approaching the background-free regime. For the proposed PandaX-III experiment, the 0ÎœÎČÎČ0\nu \beta \beta search half-life sensitivity at the 90\% confidence level would reach 2.7×10262.7 \times 10^{26}~yr with 5-year live time, a factor of 2.7 improvement over the initial design target

    Resilience-based multifactorial model of depression among people who lost an only-child in China

    Get PDF
    Objective: There are almost one million families who lost their only child in China, and 65.6% of them had severe and long lasting depression and needed timely psychointervention. This study aims to explore the relationship among resilience and its influential factors, and to compare their effect on depression. Methods: A total of 212 only-child loss person in 9 administrative regions in Changsha were assessed by using Connor-Davidson Resilience Scale, Zung Self-rating Depression Scale, Simplified Coping Style Questionnaire, Simplified Eysenck Personality Questionnaire, Social Support Rating Scale, and General Self-efficacy Scale. A hypothetical model was tested based on Kumpfer resilience framework and stress-coping theory. Results: The influential factors of resilience were: positive coping (the total effect value was 0.480), support utilization (the total effect value was 0.359), neuroticism (the total effect value was -0.326), negative coping (the total effect value was 0.279), extraversion (the total effect value was 0.219), and objective support (the total effect value was 0.077). The process of individual-environment interaction showed a greater impact on resilience, which had a direct effect on depression (the total effect value was −0.344, 67.1%), and also indirect effect through self-efficacy (the total effect value was −0.169). The total effect of resilience accounted for 20.1% of the total effect of all variables. Conclusion: Resilience mainly impacts depression directly, and can negatively predict depression in only-child loss parents. Resilience, located before self-efficacy, is a significant stress mediating variables. Personality traits and support utilization indirectly impact resilience via negative and positive coping. The key to promote the reorganization of resilience is the process of individual-environmental interaction, involving support utilization, positive coping, and some sorts of negative coping strategies, which plays an important role in developing a resilience intervention program and can improve the depression of the only-child loss person

    Enhanced Interfacial Dzyaloshinskii-Moriya Interaction in annealed Pt/Co/MgO structures

    Get PDF
    The interfacial Dzyaloshinskii-Moriya interaction (iDMI) is attracting great interests for spintronics. An iDMI constant larger than 3 mJ/m^2 is expected to minimize the size of skyrmions and to optimize the DW dynamics. In this study, we experimentally demonstrate an enhanced iDMI in Pt/Co/X/MgO ultra-thin film structures with perpendicular magnetization. The iDMI constants were measured using a field-driven creep regime domain expansion method. The enhancement of iDMI with an atomically thin insertion of Ta and Mg is comprehensively understood with the help of ab-initio calculations. Thermal annealing has been used to crystallize the MgO thin layer for improving tunneling magneto-resistance (TMR), but interestingly it also provides a further increase of the iDMI constant. An increase of the iDMI constant up to 3.3 mJ/m^2 is shown, which could be promising for the scaling down of skyrmion electronics

    The Role of Intrinsic and Surface States on the Emission Properties of Colloidal CdSe and CdSe/ZnS Quantum Dots

    Get PDF
    Time Resolved Photoluminescence (TRPL) measurements on the picosecond time scale (temporal resolution of 17 ps) on colloidal CdSe and CdSe/ZnS Quantum Dots (QDs) were performed. Transient PL spectra reveal three emission peaks with different lifetimes (60 ps, 460 ps and 9–10 ns, from the bluest to the reddest peak). By considering the characteristic decay times and by comparing the energetic separations among the states with those theoretically expected, we attribute the two higher energy peaks to ± 1Uand ± 1L bright states of the fine structure picture of spherical CdSe QDs, and the third one to surface states emission. We show that the contribution of surface emission to the PL results to be different for the two samples studied (67% in the CdSe QDs and 32% in CdSe/ZnS QDs), confirming the decisive role of the ZnS shell in the improvement of the surface passivation
    • 

    corecore