645 research outputs found

    Jacobian of meromorphic curves

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    The contact structure of two meromorphic curves gives a factorization of their jacobian.Comment: 41 pages, amstex, to be published in the Proceedings of the Indian Academy of Science

    Worldsheet Realization of the Refined Topological String

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    A worldsheet realization of the refined topological string is proposed in terms of physical string amplitudes that compute generalized N=2 F-terms of the form F_{g,n} W^{2g}Y^{2n} in the effective supergravity action. These terms involve the chiral Weyl superfield W and a superfield Y defined as an N=2 chiral projection of a particular anti-chiral T-bar vector multiplet. In Heterotic and Type I theories, obtained upon compactification on the six-dimensional manifold K3xT2, T is the usual K\"ahler modulus of the T2 torus. These amplitudes are computed exactly at the one-loop level in string theory. They are shown to reproduce the correct perturbative part of the Nekrasov partition function in the field theory limit when expanded around an SU(2) enhancement point of the string moduli space. The two deformation parameters epsilon_- and epsilon_+ of the Omega-supergravity background are then identified with the constant field-strength backgrounds for the anti-self-dual graviphoton and self-dual gauge field of the T-bar vector multiplet, respectively.Comment: 35 pages, typos corrected, published in NP

    Adverse drug reactions associated with chemotherapeutic agents used in breast cancer: Analysis of patients’ online forums

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    Background: Breast cancer is the most common type of cancer in women worldwide. The benefits of chemotherapy vary depending on the treatment regimen used and the characteristic of the tumour. However, adverse drug reactions associated with chemotherapeutic agents can cause dose delays or reductions; thereby, affecting the treatment outcomes. Objective: To explore adverse drug reactions of chemotherapeutic agents used to treat breast cancer from the patients’ perspective. Methods: A total of 110 threads from nine online discussion forums were evaluated. They were exported into NVivo for Mac where content analysis was applied. Threads were read carefully to observe emerging patterns which were then coded into sub-themes and grouped into main themes. Results: The participants’ characteristics on online discussion forums were often missing. Four hundred and eleven participants experienced 473 adverse drug reactions that were mainly associated with the nervous and immune systems. The forums’ analysis yielded three main themes: patient–patient advice, self-medication and lifestyle changes. Conclusion: Online discussion forums proposed valued source of data on adverse drug reactions associated with chemotherapeutic agents and overall patients’ experience with cancer. The adverse drug reactions experienced by patients changed their priorities and the way they dealt with the disease. Therefore, healthcare professionals must consider the patients’ experience and attitudes towards cancer when designing a treatment plan. This can be established by increasing communication between healthcare professionals and patients

    Exploring the adverse effects of chemotherapeutic agents used in the treatment of cervical and ovarian cancer from the patients' perspective: a content analysis of the online discussion forums.

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    OBJECTIVES: This study aimed to explore the adverse effects of chemotherapeutic agents used in the treatment of ovarian and cervical cancer by analysing patients' views posted in online discussion forums. METHOD: UK-centred online discussion forums were used to identify discussion threads on ovarian and cervical cancer between 2008 and 2017. The study was approved by the University of Bournemouth ethics committee. 272 discussion threads with 644 participants from four online discussion forums (Cancer Research UK, Macmillan, Ovacome and Jo's Cervical Cancer Trust) were identified. The threads were exported into NVivo and a thematic content analysis was conducted to identify study themes. RESULTS: Of the 644 participants, 19.4% had a diagnosis of cervical cancer and 80.6% had a diagnosis of ovarian cancer. Four main themes related to: (1) treatment plan, (2) adverse effects, (3) perception of treatment and (4) hospitalisation were identified. Patients' perceptions about their treatment were reported to be positive across all chemotherapeutic agents. 312 adverse effects were reported by patients with cervical cancer taking cisplatin, with fatigue (52.1%) and nausea (30.6%) being the two most frequently reported adverse effects. With regard to the treatment of ovarian cancer, 402 adverse effects were reported by patients on carboplatin and paclitaxel, with neuropathy (29.3%) and fatigue (28.0%) being the two most commonly reported adverse effects. CONCLUSION: The online discussion forums allowed patients to express their concerns in a blame-free environment that provided novel insight into the impact of chemotherapy-associated adverse effects on patients with cervical and ovarian cancers. Real-life experiences shared by patients can help the healthcare professionals to find the right balance between prolonged survival and quality of life

    On-spot quantification of modafinil in generic medicines purchased from the Internet using handheld Fourier transform-infrared, near-infrared and Raman spectroscopy

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    Poor quality medicines represent an expanding global public health threat facilitated by the Internet. A recent survey showed that one in five students have used modafinil to enhance learning ability mainly purchased from Internet sources. The aim of this work was to develop on-the-spot and simple methods for the quantification of modafinil in generic medicines using Fourier transform-infrared (FTIR), near-infrared (NIR) and Raman spectroscopy along with partial least square regression (PLSR). Modafinil tablets were measured in intact form using NIR and Raman and in powdered form using FTIR, NIR and Raman. Additionally, powder mixtures of crushed modafinil tablets and excipient(s) were prepared either by diluting the crushed tablets with excipient(s), or sequentially adding excipient(s) to the crushed tablets. Three PLSR models were constructed in MATLAB 2014a from powder mixtures and two from intact and powdered tablets. For FTIR and Raman spectroscopy, PLSR models based on tablets gave linear calibration curve with correlation coefficient (r2) values above 0.94 and a root mean square error of calibration (RMSEC) below 0.96% m/m. Conversely, the PLSR model based on powder sequential addition gave the highest accuracy using the NIR spectra (r2 = 0.99, RMSEC = 1.15% m/m). The latter model showed accuracy in predicting the concentration of the active pharmaceutical ingredient in modafinil generic medicines proving their authenticity. The overall results showed that the combination of the three spectroscopic methods with PLSR offered a rapid technique for authenticating generic modafinil medicines

    Investigating the Security of EV Charging Mobile Applications As an Attack Surface

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    The adoption rate of EVs has witnessed a significant increase in recent years driven by multiple factors, chief among which is the increased flexibility and ease of access to charging infrastructure. To improve user experience, increase system flexibility and commercialize the charging process, mobile applications have been incorporated into the EV charging ecosystem. EV charging mobile applications allow consumers to remotely trigger actions on charging stations and use functionalities such as start/stop charging sessions, pay for usage, and locate charging stations, to name a few. In this paper, we study the security posture of the EV charging ecosystem against remote attacks, which exploit the insecurity of the EV charging mobile applications as an attack surface. We leverage a combination of static and dynamic analysis techniques to analyze the security of widely used EV charging mobile applications. Our analysis of 31 widely used mobile applications and their interactions with various components such as the cloud management systems indicate the lack of user/vehicle verification and improper authorization for critical functions, which lead to remote (dis)charging session hijacking and Denial of Service (DoS) attacks against the EV charging station. Indeed, we discuss specific remote attack scenarios and their impact on the EV users. More importantly, our analysis results demonstrate the feasibility of leveraging existing vulnerabilities across various EV charging mobile applications to perform wide-scale coordinated remote charging/discharging attacks against the connected critical infrastructure (e.g., power grid), with significant undesired economical and operational implications. Finally, we propose counter measures to secure the infrastructure and impede adversaries from performing reconnaissance and launching remote attacks using compromised accounts
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