8,568 research outputs found

    Real-world Quantum Sensors: Evaluating Resources for Precision Measurement

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    Quantum physics holds the promise of enabling certain tasks with better performance than possible when only classical resources are employed. The quantum phenomena present in many experiments signify nonclassical behavior, but do not always imply superior performance. Quantifying the enhancement achieved from quantum behavior requires careful analysis of the resources involved. We analyze the specific case of parameter estimation using an optical interferometer, where increased precision can be achieved using quantum probe states. Common performance measures are examined and it is shown that some overestimate the improvement. For the simplest experimental case we compare the different measures and show this overestimate explicitly. We give the preferred analysis of real-world experiments and calculate benchmark values for experimental parameters necessary to realize a precision enhancement.Comment: 8 pages, 3 figure

    Building inclusive and welcoming student health centers for transgender students

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    INTRODUCTION: While health, wellness, and healthcare are essential to every human being, not much is known about the health and healthcare experiences of transgender students on college campuses. Understanding these healthcare experiences are important because when we recognize them, we can establish a healthy relationship of trust. There is a growing number of transgender students on West Chester University campus, who felt they were not getting the appropriate support and care. As a result, a project was started at student health services to help transgender students effectively access sensitive and welcoming care and support. METHODS: To address the needs of the transgender student population and improve the model of care at student health services, gaining a better understanding of the transgender community was a vital step. To become familiarized with their needs and health concerns, a Likert survey was created and disseminated to investigate the current issues regarding barriers of adequate care. Additionally, to identify the barriers of providing adequate care, student and health professional interviews were completed. The students involved in the interviews and questionnaires were recruited through LGBTQ Support Services Center on West Chester University’s campus. A needs assessment was also created to gain a better understanding of the health needs of the transgender student community. The available resources and services provided to the LGBTQ students at West Chester University were reviewed and compared to other colleges and universities. RESULTS: Students expressed that they felt the healthcare providers were underprepared to provide care and that their care could be improved upon. Through meeting with students and clinicians, a key barrier was the unfamiliarity with transgender health and in addressing transgender-specific health needs. It was also discovered that being unprepared to provide care, resulted in unconscious and implicit bias and the perpetuation of transgender exclusive practices. DISCUSSION: This project identified themes, barriers and areas of concern expressed by transgender students. By identifying these elements, further research can be conducted to better understand student’s perceptions and feelings when seeking healthcare, and whether these experiences impact health outcomes. The purpose of this project was to create an atmosphere geared towards providing healthcare services that are inclusive to all people of all gender identities. With the growing number of transgender students on college campuses, establishing welcoming health setting for students is very important

    In vitro evaluation of the interaction of dextrin-colistin conjugates with bacterial lipopolysaccharide.

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    Dextrin-colistin conjugates have been developed with the aim of reducing clinical toxicity associated with colistin and improving targeting to sites of bacterial infection. This study investigated the in vitro ability of these dextrin-colistin conjugates to bind and modulate bacterial lipopolysaccharide (LPS), and how this binding affects its biological activity. These results showed that colistin, and ‘amylase-activated’ dextrin-colistin conjugate to a lesser extent, bound to LPS and induced significant conformational changes to its structure. In biological studies, both colistin and dextrin-colistin conjugate effectively inhibited LPS-induced hemolysis and TNFα secretion in a concentration-dependent manner, but only dextrin-colistin conjugate did not cause additive toxicity at higher concentrations. This study provides the first direct structural experimental evidence for the binding of dextrin-colistin conjugates and LPS, providing insight into the mode of action of dextrin-colistin conjugates

    Integrated Photonic Sensing

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    Loss is a critical roadblock to achieving photonic quantum-enhanced technologies. We explore a modular platform for implementing integrated photonics experiments and consider the effects of loss at different stages of these experiments, including state preparation, manipulation and measurement. We frame our discussion mainly in the context of quantum sensing and focus particularly on the use of loss-tolerant Holland-Burnett states for optical phase estimation. In particular, we discuss spontaneous four-wave mixing in standard birefringent fibre as a source of pure, heralded single photons and present methods of optimising such sources. We also outline a route to programmable circuits which allow the control of photonic interactions even in the presence of fabrication imperfections and describe a ratiometric characterisation method for beam splitters which allows the characterisation of complex circuits without the need for full process tomography. Finally, we present a framework for performing state tomography on heralded states using lossy measurement devices. This is motivated by a calculation of the effects of fabrication imperfections on precision measurement using Holland-Burnett states.Comment: 19 pages, 7 figure

    TMEDA in Iron‐Catalyzed Hydromagnesiation: Formation of Iron(II)‐Alkyl Species for Controlled Reduction to Alkene‐Stabilized Iron(0)

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    N,N,N’,N’‐Tetramethylethylenediamine (TMEDA) has been one of the most prevalent and successful additives used in iron‐catalysis, finding application in reactions as diverse as cross‐coupling, C‐H activation and borylation. However, the role that TMEDA plays in these reactions remains largely undefined. Herein, studying the iron‐catalyzed hydromagnesiation of styrene derivatives using TMEDA has provided molecular‐level insight into the role of TMEDA in achieving effective catalysis. Key is the initial formation of TMEDA‐iron(II) alkyl species which undergo a controlled reduction to selectively form catalytically active styrene‐stabilized iron(0)‐alkyl complexes. While TMEDA is not bound to the catalytically active species, these active iron(0) complexes cannot be accessed in the absence of TMEDA. This mode of action, allowing for controlled reduction and access to iron(0) species, represents a new paradigm for the role of this important reaction additive in iron catalysis

    Prevalence and correlates of reproductive coercion across ten sites: commonalities and divergence

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    Background Reproductive coercion (RC) is a type of abuse where a partner asserts control over a woman’s reproductive health trajectories. Recent research emphasizes that RC experiences may differ within and across low- and middle-income countries (LMICs), as compared to higher income contexts, given social pressures surrounding childbearing. To date, nationally representative surveys have lacked comprehensive measures for RC, leading to gaps in understanding its prevalence and risk factors. Across eight LMICs (10 sites), we aimed to (1) validate the RC Scale; (2) calculate prevalence of RC and specific behaviors; and (3) assess correlates of RC. Methods This analysis leverages cross-sectional Performance Monitoring for Action (PMA) data collected from November 2020 to May 2022. Analyses were limited to women in need of contraception (Burkina Faso n = 2767; Côte d’Ivoire n = 1561; Kongo Central, Democratic Republic of Congo (DRC) n = 830; Kinshasa, DRC n = 846; Kenya n = 4588; Kano, Nigeria n = 535; Lagos, Nigeria n = 612; Niger n = 1525; Rajasthan, India n = 3017; Uganda n = 2020). Past-year RC was assessed via five items adapted from the original RC Scale and previously tested in LMICs. Confirmatory factor analysis examined fit statistics by site. Per-item and overall prevalence were calculated. Site-specific bivariate and multivariable logistic regression examined RC correlates across the socioecological framework. Results Confirmatory factor analysis confirmed goodness of fit across all sites, with moderate internal consistency (alpha range: 0.66 Cote d’Ivoire–0.89 Kinshasa, DRC/Lagos, Nigeria). Past-year reported prevalence of RC was highest in Kongo Central, DRC (20.3%) and lowest in Niger (3.1%). Prevalence of individual items varied substantially by geography. Polygyny was the most common RC risk factor across six sites (adjusted odds ratio (aOR) range: 1.59–10.76). Increased partner education levels were protective in Kenya and Kano, Nigeria (aOR range: 0.23–0.67). Other assessed correlates differed by site. Conclusions Understanding RC prevalence and behaviors is central to providing woman-centered reproductive care. RC was most strongly correlated with factors at the partner dyad level; future research is needed to unpack the relative contributions of relationship power dynamics versus cultural norms surrounding childbearing. Family plannin

    Colloquium: Trapped ions as quantum bits -- essential numerical tools

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    Trapped, laser-cooled atoms and ions are quantum systems which can be experimentally controlled with an as yet unmatched degree of precision. Due to the control of the motion and the internal degrees of freedom, these quantum systems can be adequately described by a well known Hamiltonian. In this colloquium, we present powerful numerical tools for the optimization of the external control of the motional and internal states of trapped neutral atoms, explicitly applied to the case of trapped laser-cooled ions in a segmented ion-trap. We then delve into solving inverse problems, when optimizing trapping potentials for ions. Our presentation is complemented by a quantum mechanical treatment of the wavepacket dynamics of a trapped ion. Efficient numerical solvers for both time-independent and time-dependent problems are provided. Shaping the motional wavefunctions and optimizing a quantum gate is realized by the application of quantum optimal control techniques. The numerical methods presented can also be used to gain an intuitive understanding of quantum experiments with trapped ions by performing virtual simulated experiments on a personal computer. Code and executables are supplied as supplementary online material (http://kilian-singer.de/ent).Comment: accepted for publication in Review of Modern Physics 201

    Epidemiological profile and clinico-pathological features of pediatric gynecological cancers at Moi Teaching & Referral Hospital, Kenya

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    Background: The main pediatric (0–18 years) gynecologic cancers include stromal carcinomas (juvenile granulosa cell tumors and Sertoli-Leydig cell tumors), genital rhabdomyosarcomas and ovarian germ cell. Outcomes depend on time of diagnosis, stage, tumor type and treatment which can have long-term effects on the reproductive career of these patients. This study seeks to analyze the trends in clinical-pathologic presentation, treatment and outcomes in the cases seen at our facility. This is the first paper identifying these cancers published from sub-Saharan Africa. Method: Retrospective review of clinico-pathologic profiles and treatment outcomes of pediatric gynecologic oncology patients managed at MTRH between 2010 and 2020. Data was abstracted from gynecologic oncology database and medical charts. Results: Records of 40 patients were analyzed. Most, (92.5%, 37/40) of the patients were between 10 and 18 years. Ovarian germ cell tumors were the leading histological diagnosis in 72.5% (29/40) of the patients; with dysgerminomas being the commonest subtype seen in 12 of the 37 patients (32.4%). The patients received platinum-based chemotherapy in 70% of cases (28/40). There were 14 deaths among the 40 patients (35%) Conclusion: Surgery remains the main stay of treatment and fertility-sparing surgery with or without adjuvant platinum-based chemotherapy are the standard of care with excellent prognosis following early detection and treatment initiation. LMICs face several challenges in access to quality care and that affects survival of these patients. Due to its commonality, ovarian germ cell cancers warrant a high index of suspicion amongst primary care providers attending to adnexal masses in this age group
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