2,293 research outputs found

    The 2020 Covid-19 pandemic and global value chains

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    This paper considers the impact of the Covid-19 pandemic on firm strategies and, in particular, the configuration of firms’ global value chains (GVCs) once the pandemic has been brought under control. The merits of alternative location strategies (international diversification vs reshoring) are compared, as are the merits of different governance arrangements (internalization vs externalization) for GVC activities. The possibility of fire-sale foreign direct investment is raised, and the wider geopolitical context is emphasized. The widespread human tragedy is noted, as is the dilemma facing national governments around the world in balancing lives and livelihoods

    What do γ\gamma-ray bursts look like?

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    There have been great and rapid progresses in the field of γ\gamma-ray bursts (denoted as GRBs) since BeppoSAX and other telescopes discovered their afterglows in 1997. Here, we will first give a brief review on the observational facts of GRBs and direct understanding from these facts, which lead to the standard fireball model. The dynamical evolution of the fireball is discussed, especially a generic model is proposed to describe the whole dynamical evolution of GRB remnant from highly radiative to adiabatic, and from ultra-relativistic to non-relativistic phase. Then, Various deviations from the standard model are discussed to give new information about GRBs and their environment. In order to relax the energy crisis, the beaming effects and their possible observational evidences are also discussed in GRB's radiations.Comment: 10 pages, Latex. Invited talk at the Pacific Rim Conference on Stellar Astrophysics, Hong Kong, China, Aug. 199

    Identification and functional characterisation of CRK12:CYC9, a novel cyclin-dependent kinase (CDK)-cyclin complex in Trypanosoma brucei

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    The protozoan parasite, Trypanosoma brucei, is spread by the tsetse fly and causes trypanosomiasis in humans and animals. Both the life cycle and cell cycle of the parasite are complex. Trypanosomes have eleven cdc2-related kinases (CRKs) and ten cyclins, an unusually large number for a single celled organism. To date, relatively little is known about the function of many of the CRKs and cyclins, and only CRK3 has previously been shown to be cyclin-dependent in vivo. Here we report the identification of a previously uncharacterised CRK:cyclin complex between CRK12 and the putative transcriptional cyclin, CYC9. CRK12:CYC9 interact to form an active protein kinase complex in procyclic and bloodstream T. brucei. Both CRK12 and CYC9 are essential for the proliferation of bloodstream trypanosomes in vitro, and we show that CRK12 is also essential for survival of T. brucei in a mouse model, providing genetic validation of CRK12:CYC9 as a novel drug target for trypanosomiasis. Further, functional characterisation of CRK12 and CYC9 using RNA interference reveals roles for these proteins in endocytosis and cytokinesis, respectively

    Clinical significance of preoperative serum interleukin-6 and C-reactive protein level in breast cancer patients

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    <p>Abstract</p> <p>Background</p> <p>Breast cancer is a disease that continues to plague females during their entire lifetime. IL-6 and CRP are found to be elevated in various inflammatory and malignant diseases and their levels are found to correlate with the extent of the disease. The primary objective of this study was to determine the preoperative serum levels of IL-6 and CRP in breast carcinoma, and to correlate them with the staging of the disease and the prognosis.</p> <p>Methods</p> <p>59 female patients admitted for breast cancer were identified for the study and were subjected to thorough evaluation. Serum levels of IL-6 were assessed via Enzyme-Linked Immuno-Sorbent Assay (ELISA), and CRP was measured via immunoturbidimetry. Histological findings included tumour size, lymph node (LN) metastasis, and tumour staging. Relevant investigations were made to find out the presence of distant metastasis. Statistical analysis of the data was then processed.</p> <p>Results</p> <p>Increases in cancer invasion and staging are generally associated with increases in preoperative serum IL-6 levels. IL-6 and CRP levels correlated with LN metastasis (P < 0.001, P < 0.001) and TNM stage (P < 0.001, P < 0.001). Tumour invasion and the presence of distant metastasis is associated with higher IL-6 levels (P = 0.001, P = 0.009). When we established the cutoff value for IL-6 level (20.55 pg/dl) by ROC curve, we noted a significant difference in overall survival (OS; P = 0.008). However, CRP evidenced no significance with regard to patient's OS levels. Serum IL-6 levels were correlated positively with CRP levels (r2 = 0.579, P < 0.01)</p> <p>Conclusion</p> <p>Serum levels of IL-6 correlates well with the extent of tumor invasion, LN metastasis, distant metastasis and TNM staging thus enveloping all aspects of breast cancer.</p

    Persistent isolated impairment of gas transfer following COVID-19 pneumonitis relates to perfusion defects on dual-energy computed tomography

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    Breathlessness is common in patients after COVID-19 [1]. Patients may have an isolated impairment of gas transfer (diffusion of the lung for carbon monoxide, DLCO) at lung function testing, often without obvious interstitial lung disease or classical pulmonary emboli (PE) on imaging. Iodine maps from post-COVID patients undergoing dual energy computed tomography (DECT) demonstrate hypoenhancement in areas of normal lung parenchyma [2] (figure 1). We hypothesized that in breathless patients recovering from COVID-19, low DLCO would correlate with a CT marker of lung perfusion, measured using DECT-derived iodine enhancement, including in patients where parenchymal disease was absent. As an even more specific indicator for the pulmonary vascular compartment, we hypothesized that KCO (DLCO corrected for alveolar volume) would even better correlate with DECT perfusion, and more so than forced vital capacity (FVC) and CT measures of interstitial lung involvement

    Physical activity in Hodgkin's lymphoma survivors with and without chronic fatigue compared with the general population – a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Hodgkin's lymphoma survivors (HLSs) commonly report chronic fatigue, defined as high levels of fatigue for 6 months or more. Underlying mechanisms are poorly understood. Based upon knowledge from other populations, lifestyle parameters may be related to this increased and persistent fatigue. The primary objective of the present study was to assess self-reported levels of physical activity, smoking habits and sleep patterns in HLSs with and without chronic fatigue. The secondary objective was to compare these results with data from age and gender adjusted data from the general population (Gen-Pop).</p> <p>Methods</p> <p>The Fatigue Questionnaire (FQ) and questions about daily smoking, sleep patterns and level of physical activity were completed by 476 HLSs treated at Rikshospitalet-Radiumhospitalet Trust (RR). The Gen-Pop data was derived from 56.999 inhabitants in a Norwegian county responding to a mail survey. Fischer's exact test, chi square test and t-tests were used to compare groups. P-values < .05 were considered statistically significant. A logistic regression analysis was performed in comparing the Gen-Pop with the HLSs.</p> <p>Results</p> <p>Level of physical activity, smoking habits and sleep patterns did not differ significantly between HLSs with and without chronic fatigue. The multivariate logistic regression analysis adjusting for different covariates, showed significantly more physically active men among HLSs compared with the Gen-Pop (OR = 1.50, CI 1.04 – 2.17), p = .031. No significant difference was found among females (OR = 1.20, CI = 0.83 – 1.74), p = .33.</p> <p>Conclusion</p> <p>Lifestyle parameters did not seem to be related to increased and persistent fatigue among HLSs. The results may indicate that the experience of Hodgkin's lymphoma increases the level of physical activity among male HLSs.</p

    Drama as a pedagogical tool for practicing death notification-experiences from Swedish medical students

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    <p>Abstract</p> <p>Background</p> <p>One of the toughest tasks in any profession is the deliverance of death notification. Marathon Death is an exercise conducted during the fourth year of medical school in northern Sweden to prepare students for this responsibility. The exercise is designed to enable students to gain insight into the emotional and formal procedure of delivering death notifications. The exercise is inspired by Augusto Boal's work around Forum Theatre and is analyzed using video playback. The aim of the study was to explore reflections, attitudes and ideas toward training in delivering death notifications among medical students who participate in the Marathon Death exercise based on forum play.</p> <p>Methods</p> <p>After participation in the Marathon Death exercise, students completed semi-structured interviews. The transcribed interviews were analyzed using the principles of qualitative content analysis including a deductive content analysis approach with a structured matrix based on Bloom's taxonomy domains.</p> <p>Results</p> <p>The Marathon Death exercise was perceived as emotionally loaded, realistic and valuable for the future professional role as a physician. The deliverance of a death notification to the next of kin that a loved one has died was perceived as difficult. The exercise conjured emotions such as positive expectations and sheer anxiety. Students perceived participation in the exercise as an important learning experience, discovering that they had the capacity to manage such a difficult situation. The feedback from the video playback of the exercise and the feedback from fellow students and teachers enhanced the learning experience.</p> <p>Conclusions</p> <p>The exercise, Marathon Death, based on forum play with video playback is a useful pedagogical tool that enables students to practice delivering death notification. The ability to practice under realistic conditions contributes to reinforce students in preparation for their future professional role.</p

    Detection of Gamma-Ray Emission from the Starburst Galaxies M82 and NGC 253 with the Large Area Telescope on Fermi

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    We report the detection of high-energy gamma-ray emission from two starburst galaxies using data obtained with the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. Steady point-like emission above 200 MeV has been detected at significance levels of 6.8 sigma and 4.8 sigma respectively, from sources positionally coincident with locations of the starburst galaxies M82 and NGC 253. The total fluxes of the sources are consistent with gamma-ray emission originating from the interaction of cosmic rays with local interstellar gas and radiation fields and constitute evidence for a link between massive star formation and gamma-ray emission in star-forming galaxies.Comment: Submitted to ApJ Letter

    Molecular biology of breast cancer metastasis: The use of mathematical models to determine relapse and to predict response to chemotherapy in breast cancer

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    Breast cancer mortality rates have shown only modest improvemen despite the advent of effective chemotherapeutic agents which have been administered to a large percentage of women with breast cancer. In an effort to improve breast cancer treatment strategies, a variety of mathematical models have been developed that describe the natural history of breast cancer and the effects of treatment on the cancer. These models help researchers to develop, quantify, and test various treatment hypotheses quickly and efficiently. The present review discusses several of these models, with a focus on how they have been used to predict the initiation time of metastatic growth, the effect of operative therapy on the growth of metastases, and the optimal administration strategy for chemotherapy
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