10,145 research outputs found

    The anti-feminist reconstruction of the midlife crisis: Popular psychology, journalism and social science in 1970s America

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    The “midlife crisis” was first successfully promoted in the United States with journalist Gail Sheehy’s Passages (1976) as a feminist idea, which described middle life as the point when men and women abandon traditional gender roles. Psychological experts responded with a male-centered definition of middle age, which banned women from reimagining their lives. Presented and received as more scientific, this became the dominant meaning of “midlife crisis.” This paper reverses histories of “popularization” by tracing how an idea moved from popular culture into academia. It examines the gender politics of scientific demarcation and shows that the midlife crisis has historical roots in debates about gender roles.Arts and Humanities Research Council, Studienstiftung des Deutschen Volke

    Hybrid solid state qubits: the powerful role of electron spins

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    We review progress on the use of electron spins to store and process quantum information, with particular focus on the ability of the electron spin to interact with multiple quantum degrees of freedom. We examine the benefits of hybrid quantum bits (qubits) in the solid state that are based on coupling electron spins to nuclear spin, electron charge, optical photons, and superconducting qubits. These benefits include the coherent storage of qubits for times exceeding seconds, fast qubit manipulation, single qubit measurement, and scalable methods for entangling spatially separated matter-based qubits. In this way, the key strengths of different physical qubit implementations are brought together, laying the foundation for practical solid-state quantum technologies.Comment: 54 pages, 7 figure

    Variational methods for He-4 using a modern He-He potential

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    The two-body potential HFD-B3-FC11 for He-He interactions proposed by Aziz and collaborators is analyzed using the variational Monte Carlo method. Complementary work using the Green's function Monte Carlo method is presented as well. The importance of three-body effects in the description of the interactions are considered and good evidence is presented for using a potential that takes into account these effects even at the equilibrium density of systems of He-4 atoms. An examination of the most usual trial functions forms employed in the studies of these systems, some experiments with other correlation factors, and some methodological notes complete this investigation. [S0163-1829(99)02741-1].6017123421234

    On RAF Sets and Autocatalytic Cycles in Random Reaction Networks

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    The emergence of autocatalytic sets of molecules seems to have played an important role in the origin of life context. Although the possibility to reproduce this emergence in laboratory has received considerable attention, this is still far from being achieved. In order to unravel some key properties enabling the emergence of structures potentially able to sustain their own existence and growth, in this work we investigate the probability to observe them in ensembles of random catalytic reaction networks characterized by different structural properties. From the point of view of network topology, an autocatalytic set have been defined either in term of strongly connected components (SCCs) or as reflexively autocatalytic and food-generated sets (RAFs). We observe that the average level of catalysis differently affects the probability to observe a SCC or a RAF, highlighting the existence of a region where the former can be observed, whereas the latter cannot. This parameter also affects the composition of the RAF, which can be further characterized into linear structures, autocatalysis or SCCs. Interestingly, we show that the different network topology (uniform as opposed to power-law catalysis systems) does not have a significantly divergent impact on SCCs and RAFs appearance, whereas the proportion between cleavages and condensations seems instead to play a role. A major factor that limits the probability of RAF appearance and that may explain some of the difficulties encountered in laboratory seems to be the presence of molecules which can accumulate without being substrate or catalyst of any reaction.Comment: pp 113-12

    Towards accelerated autolysis? Dynamics of phenolics, proteins, amino acids and lipids in response to novel treatments and during ageing of sparkling wine

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    Premium sparkling wine produced by the traditional method (analogous to the French mĂ©thode champenoise) is characterised by the development of aged wine character as a result of a second fermentation in the bottle with lees contact and lengthy ageing. Treatments (microwave, ultrasound, or ÎČ-glucanase enzymes) were applied to disrupt the cell wall of Saccharomyces cerevisiae and added to the tirage liquor for the second fermentation of Chardonnay-Pinot Noir base wine cuvĂ©e and compared to a control, to assess effects on the release of phenolics, proteins, amino acids, and lipids at 6, 12 and 18 months post-tirage. General responses to wine ageing included a 60% increase in the total phenolic content of older sparkling wines relative to younger wines and an increase in protein concentration from 6 to 12 months bottle age. Microwave and ÎČ-glucanase enzyme treatments of yeast during tirage preparation were associated with a 10% increase in total free amino acid concentration and a 10% increase in proline concentration at 18 months bottle age, compared to control and ultrasound treatment. Furthermore, microwave treatment was associated with elevated asparagine content in wine at 18 months bottle age, relative to the control and the other wines. The ÎČ-glucanase enzyme and ultrasound treatments were associated with significant accumulation of total lipids, which were driven by 2-fold increases in the phospholipid and monoacylglycerol components in wine at 18 months bottle age and, furthermore, the microwave treatment was associated with elevated triacylglycerol at 18 months bottle age. This study demonstrates that the use of yeast treatments at the tirage stage of sparkling wine production presents an opportunity to manipulate wine composition

    3D-nanoprinted antiresonant hollow-core microgap waveguide: an on-chip platform for integrated photonic devices and sensors.

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    Due to their unique capabilities, hollow-core waveguides are playing an increasingly important role, especially in meeting the growing demand for integrated and low-cost photonic devices and sensors. Here, we present the antiresonant hollow-core microgap waveguide as a platform for the on-chip investigation of light-gas interaction over centimeter-long distances. The design consists of hollow-core segments separated by gaps that allow external access to the core region, while samples with lengths up to 5 cm were realized on silicon chips through 3D-nanoprinting using two-photon absorption based direct laser writing. The agreement of mathematical models, numerical simulations and experiments illustrates the importance of the antiresonance effect in that context. Our study shows the modal loss, the effect of gap size and the spectral tuning potential, with highlights including extremely broadband transmission windows (>200 nm), very high contrast resonance (>60 dB), exceptionally high structural openness factor (18%) and spectral control by nanoprinting (control over dimensions with step sizes (i.e., increments) of 60 nm). The application potential was demonstrated in the context of laser scanning absorption spectroscopy of ammonia, showing diffusion speeds comparable to bulk diffusion and a low detection limit. Due to these unique properties, application of this platform can be anticipated in a variety of spectroscopy-related fields, including bioanalytics, environmental sciences, and life sciences

    A priority paper for the societal and ethical aspects of synthetic biology

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    As synthetic biology develops into a promising science and engineering field, we need to have clear ideas and priorities regarding its safety, security, ethical and public dialogue implications. Based on an extensive literature search, interviews with scientists, social scientists, a 4 week long public e-forum, and consultation with several stakeholders from science, industry and civil society organisations, we compiled a list of priority topics regarding societal issues of synthetic biology for the years ahead. The points presented here are intended to encourage all stakeholders to engage in the prioritisation of these issues and to participate in a continuous dialogue, with the ultimate goal of providing a basis for a multi-stakeholder governance in synthetic biology. Here we show possible ways to solve the challenges to synthetic biology in the field of safety, security, ethics and the science–public interface

    Rapid diagnostic tests for molecular surveillance of Plasmodium falciparum malaria -assessment of DNA extraction methods and field applicability

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    Background: The need for new malaria surveillance tools and strategies is critical, given improved global malaria control and regional elimination efforts. High quality Plasmodium falciparum DNA can reliably be extracted from malaria rapid diagnostic tests (RDTs). Together with highly sensitive molecular assays, wide scale collection of used RDTs may serve as a modern tool for improved malaria case detection and drug resistance surveillance. However, comparative studies of DNA extraction efficiency from RDTs and the field applicability are lacking. The aim of this study was to compare and evaluate different methods of DNA extraction from RDTs and to test the field applicability for the purpose of molecular epidemiological investigations. Methods: DNA was extracted from two RDT devices (Paracheck-PfW and SD Bioline Malaria Pf/Pan (R)), seeded in vitro with 10-fold dilutions of cultured 3D7 P. falciparum parasites diluted in malaria negative whole blood. The level of P. falciparum detection was determined for each extraction method and RDT device with multiple nested-PCR and real-time PCR assays. The field applicability was tested on 855 paired RDT (Paracheck-Pf) and filter paper (Whatman (R) 3MM) blood samples (734 RDT negative and 121 RDT positive samples) collected from febrile patients in Zanzibar 2010. RDT positive samples were genotyped at four key single nucleotide polymorphisms (SNPs) in pfmdr1 and pfcrt as well as for pfmdr1 copy number, all associated with anti-malarial drug resistance. Results: The P. falciparum DNA detection limit varied with RDT device and extraction method. Chelex-100 extraction performed best for all extraction matrixes. There was no statistically significant difference in PCR detection rates in DNA extracted from RDTs and filter paper field samples. Similarly there were no significant differences in the PCR success rates and genotyping outcomes for the respective SNPs in the 121 RDT positive samples. Conclusions: The results support RDTs as a valuable source of parasite DNA and provide evidence for RDT-DNA extraction for improved malaria case detection, molecular drug resistance surveillance, and RDT quality control.ACT Consortium through Bill and Melinda Gates Foundation; Swedish International Development Agency (SIDA) [SWE 2009-193]; Swedish Civil Contingencies Agency (MSB) [2010-7991]; Swedish Medical Research Council (VR) [2009-3785]; Goljes Foundationinfo:eu-repo/semantics/publishedVersio
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