3,176 research outputs found

    Numerical Simulation of Nano Scanning in Intermittent-Contact Mode AFM under Q control

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    We investigate nano scanning in tapping mode atomic force microscopy (AFM) under quality (Q) control via numerical simulations performed in SIMULINK. We focus on the simulation of whole scan process rather than the simulation of cantilever dynamics and the force interactions between the probe tip and the surface alone, as in most of the earlier numerical studies. This enables us to quantify the scan performance under Q control for different scan settings. Using the numerical simulations, we first investigate the effect of elastic modulus of sample (relative to the substrate surface) and probe stiffness on the scan results. Our numerical simulations show that scanning in attractive regime using soft cantilevers with high Qeff results in a better image quality. We, then demonstrate the trade-off in setting the effective Q factor (Qeff) of the probe in Q control: low values of Qeff cause an increase in tapping forces while higher ones limit the maximum achievable scan speed due to the slow response of the cantilever to the rapid changes in surface profile. Finally, we show that it is possible to achieve higher scan speeds without causing an increase in the tapping forces using adaptive Q control (AQC), in which the Q factor of the probe is changed instantaneously depending on the magnitude of the error signal in oscillation amplitude. The scan performance of AQC is quantitatively compared to that of standard Q control using iso-error curves obtained from numerical simulations first and then the results are validated through scan experiments performed using a physical set-up

    A survey of Australian midwives’ knowledge, experience, and training needs in relation to female genital mutilation

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    © 2017 Australian College of Midwives Background: Female genital mutilation (FGM) involves partial or total removal of the external female genitalia or any other injury for non-medical reasons. Due to international migration patterns, health professionals in high income countries are increasingly caring for women with FGM. Few studies explored the knowledge and skills of midwives in high income countries. Aim: To explore the knowledge, experience and needs of midwives in relation to the care of women with FGM. Methods: An online self-administered descriptive survey was designed and advertised through the Australian College of Midwives’ website. Results: Of the 198 midwives (24%) did not know the correct classification of FGM. Almost half of the respondents (48%) reported they had not received FGM training during their midwifery education. Midwives (8%) had been asked, or knew of others who had been asked to perform FGM in Australia. Many midwives were not clear about the law or health data related to FGM and were not aware of referral paths for affected women. Conclusion: As frontline providers, midwives must have appropriate up-to-date clinical skills and knowledge to ensure they are able to provide women with FGM the care they need and deserve. Midwives have a critical role to play in the collection of FGM related data to assist with health service planning and to prevent FGM by working closely with women and communities they serve to educate and advocate for its abandonment. Therefore, addressing educational gaps and training needs are key strategies to deliver optimal quality of care

    Preventing female genital mutilation in high income countries: A systematic review of the evidence

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    © 2019 The Author(s). Background: Female genital mutilation (FGM) is prevalent in communities of migration. Given the harmful effects of the practice and its illegal status in many countries, there have been concerted primary, secondary and tertiary prevention efforts to protect girls from FGM. However, there is paucity of evidence concerning useful strategies and approaches to prevent FGM and improve the health and social outcomes of affected women and girls. Methods: We analysed peer-reviewed and grey literature to extract the evidence for FGM prevention interventions from a public health perspective in high income countries by a systematic search of bibliographic databases and websites using appropriate keywords. Identified publications were screened against selection criteria, following the PRISMA guidelines. We examined the characteristics of prevention interventions, including their programmatic approaches and strategies, target audiences and evaluation findings using an apriori template. Findings: Eleven documents included in this review described primary and secondary prevention activities. High income countries have given attention to legislative action, bureaucratic interventions to address social injustice and protect those at risk of FGM, alongside prevention activities that favour health persuasion, foster engagement with the local community through outreach and the involvement of community champions, healthcare professional training and capacity strengthening. Study types are largely process evaluations that include measures of short-term outcomes (pre- and post-changes in attitude, knowledge and confidence or audits of practices). There is a dearth of evaluative research focused on empowerment-oriented preventative activities that involve individual women and girls who are affected by FGM. Beattie's framework provides a useful way of articulating negotiated and authoritative prevention actions required to address FGM at national and local levels. Conclusion: FGM is a complex and deeply rooted sociocultural issue that requires a multifaceted response that encompasses socio-economic, physical and environmental factors, education and learning, health services and facilities, and community mobilisation activities. Investment in the rigorous longitudinal evaluation of FGM health prevention efforts are needed to provide strong evidence of impact to guide future decision making. A national evidence-based framework would bring logic, clarity, comprehension, evidence and economically more effective response for current and future prevention interventions addressing FGM in high income countries

    Evidence to inform education, training and supportive work environments for midwives involved in the care of women with female genital mutilation: A review of global experience

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    © 2014 Elsevier Ltd. Objective: to identify how midwives in low and middle income countries (LMIC) and high income countries (HIC) care for women with female genital mutilation (FGM), their perceived challenges and what professional development and workplace strategies might better support midwives to provide appropriate quality care. Design: an integrative review involving a narrative synthesis of the literature was undertaken to include peer reviewed research literature published between 2004 and 2014. Findings: 10 papers were included in the review, two from LMIC and eight from HIC. A lack of technical knowledge and limited cultural competency was identified, as well as socio-cultural challenges in the abandonment process of the practice, particularly in LMIC settings. Training in the area of FGM was limited. One study reported the outcomes of an education initiative that was found to be beneficial. Key conclusions: professional education and training, a working environment supported by guidelines and responsive policy and community education, are necessary to enable midwives to improve the care of women with FGM and advocate against the practice. Implications for practice: improved opportunities for midwives to learn about FGM and receive advice and support, alongside opportunities for collaborative practice in contexts that enable the effective reporting of FGM to authorities, may be beneficial and require further investigation

    Generative discriminative models for multivariate inference and statistical mapping in medical imaging

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    This paper presents a general framework for obtaining interpretable multivariate discriminative models that allow efficient statistical inference for neuroimage analysis. The framework, termed generative discriminative machine (GDM), augments discriminative models with a generative regularization term. We demonstrate that the proposed formulation can be optimized in closed form and in dual space, allowing efficient computation for high dimensional neuroimaging datasets. Furthermore, we provide an analytic estimation of the null distribution of the model parameters, which enables efficient statistical inference and p-value computation without the need for permutation testing. We compared the proposed method with both purely generative and discriminative learning methods in two large structural magnetic resonance imaging (sMRI) datasets of Alzheimer's disease (AD) (n=415) and Schizophrenia (n=853). Using the AD dataset, we demonstrated the ability of GDM to robustly handle confounding variations. Using Schizophrenia dataset, we demonstrated the ability of GDM to handle multi-site studies. Taken together, the results underline the potential of the proposed approach for neuroimaging analyses.Comment: To appear in MICCAI 2018 proceeding

    Are treatment guides and rational drug use policies adequately exploited in combating respiratory system diseases?

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    SummaryThe aim of the present study was to increase awareness regarding the rational use of medicines. The data were obtained via the Material Resources Management System Module of the Ministry of Health. For the appropriateness of treatments, the Global Initiative for Asthma, the Global Initiative for Chronic Obstructive Lung Disease, and the guidelines for the rational use of medicines were used. We also investigated whether any de-escalation method or physical exercise was performed. Statistical analyses were performed using descriptive statistics to determine the mean, standard deviation, and frequency. The results showed that healthcare providers ignored potential drug reactions or adverse interactions, and reflecting the lack of adherence to the current treatment guides, 35.8% irrational use of medicines was recorded. Thus, de-escalation methods should be used to decrease costs or narrow the antibiotic spectrum, antibiotic selection should consider the resistance patterns, culturing methods should be analyzed, and monotherapy should be preferred over combination treatments

    CoDet: Sentence-based containment detection in news corpora

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    We study a generalized version of the near-duplicate detection problem which concerns whether a document is a subset of another document. In text-based applications, document containment can be observed in exact-duplicates, near-duplicates, or containments, where the first two are special cases of the third. We introduce a novel method, called CoDet, which focuses particularly on this problem, and compare its performance with four well-known near-duplicate detection methods (DSC, full fingerprinting, I-Match, and SimHash) that are adapted to containment detection. Our method is expandable to different domains, and especially suitable for streaming news. Experimental results show that CoDet effectively and efficiently produces remarkable results in detecting containments. © 2011 ACM

    The effect of racemic gossypol and AT-101 on angiogenic profile of OVCAR-3 cells: a preliminary molecular framework for gossypol enantiomers

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    To compare the effect of racemic gossypol with its (–)/(–) enantiomer (AT-101) on expression profiles of angiogenic molecules by mRNA levels in human ovarian cancer cell line OVCAR-3. Methods: Cell viability assay (2,3-bis (2-methoxy-4-nitro-5- sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide) was used to detect cytotoxicity of gossypol enantiomers. DNA fragmentation by an enzyme-linked immunosorbent (ELISA) assay was used to evaluate the rate of apoptosis. The mRNA expression levels of angiogenic molecules were investigated by Human Angiogenesis RT2 ProfilerTM PCR Array (SuperArray, Frederick, MD). Results: Both racemic form and AT-101 resulted in a significant cytotoxicity and induced apoptosis. This effect was observed in a dose- and time dependent manner. However, AT-101 was much more potent. In addition, the treatment of 10 μM of racemic gossypol alone and 3 μM of AT-101 alone resulted in significant down-regulation (≥ 3 fold) in mRNA levels of some pivotal angiogenic molecules in OVCAR-3, but altered gene profiles were different by the treatment of each enantiomer. Conclusion: The efficacy of two gossypol enantiomers in OVCAR-3 cells showed distinction. AT-101 was much more potent than racemic gossypol, not only by means of cell death and apoptosis, but also by modulation of angiogenic molecules released from OVCAR-3 cells. Further studies with endothelial cells should be done to verify the anti-angiogenic effect of gossypol enantiomers in cancer treatment

    Competing Ultrafast Energy Relaxation Pathways in Photoexcited Graphene

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    For most optoelectronic applications of graphene a thorough understanding of the processes that govern energy relaxation of photoexcited carriers is essential. The ultrafast energy relaxation in graphene occurs through two competing pathways: carrier-carrier scattering -- creating an elevated carrier temperature -- and optical phonon emission. At present, it is not clear what determines the dominating relaxation pathway. Here we reach a unifying picture of the ultrafast energy relaxation by investigating the terahertz photoconductivity, while varying the Fermi energy, photon energy, and fluence over a wide range. We find that sufficiently low fluence (\lesssim 4 μ\muJ/cm2^2) in conjunction with sufficiently high Fermi energy (\gtrsim 0.1 eV) gives rise to energy relaxation that is dominated by carrier-carrier scattering, which leads to efficient carrier heating. Upon increasing the fluence or decreasing the Fermi energy, the carrier heating efficiency decreases, presumably due to energy relaxation that becomes increasingly dominated by phonon emission. Carrier heating through carrier-carrier scattering accounts for the negative photoconductivity for doped graphene observed at terahertz frequencies. We present a simple model that reproduces the data for a wide range of Fermi levels and excitation energies, and allows us to qualitatively assess how the branching ratio between the two distinct relaxation pathways depends on excitation fluence and Fermi energy.Comment: Nano Letters 201

    The monocyte-macrophage axis in the intestine

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    Macrophages are one of the most abundant leucocytes in the intestinal mucosa where they are essential for maintaining homeostasis. However, they are also implicated in the pathogenesis of disorders such as inflammatory bowel disease (IBD), offering potential targets for novel therapies. Here we discuss the function of intestinal monocytes and macrophages during homeostasis and describe how these populations and their functions change during infection and inflammation. Furthermore, we review the current evidence that the intestinal macrophage pool requires continual renewal from circulating blood monocytes, unlike most other tissue macrophages which appear to derive from primitive precursors that subsequently self-renew
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