3,603 research outputs found

    Tuning the relaxation rates of dual-mode T?/T? nanoparticle contrast agents: a study into the ideal system

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    Magnetic resonance imaging (MRI) is an excellent imaging modality. However the low sensitivity of the technique poses a challenge to achieving an accurate image of function at the molecular level. To overcome this, contrast agents are used; typically gadolinium based agents for T? weighted imaging, or iron oxide based agents for T? imaging. Traditionally, only one imaging mode is used per diagnosis although several physiological situations are known to interfere with the signal induced by the contrast agents in each individual imaging mode acquisition. Recently, the combination of both T? and T? imaging capabilities into a single platform has emerged as a tool to reduce uncertainties in MR image analysis. To date, contradicting reports on the effect on the contrast of the coupling of a T? and T? agent have hampered the application of these specialised probes. Herein, we present a systematic experimental study on a range of gadolinium-labelled magnetite nanoparticles envisioned to bring some light into the mechanism of interaction between T? and T? components, and advance towards the design of efficient (dual) T? and T? MRI probes. Unexpected behaviours observed in some of the constructs will be discussed. In this study, we demonstrate that the relaxivity of such multimodal probes can be rationally tuned to obtain unmatched potentials in MR imaging, exemplified by preparation of the magnetite-based nanoparticle with the highest T? relaxivity described to date

    Two Foraging Algorithms for Robot Swarms Using Only Local Communication

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    Large collections of robots have the potential to perform tasks collectively using distributed control algorithms. These algorithms require communication between robots to allow the robots to coordinate their behavior and act as a collective. In this paper we describe two algorithms which allow coordination between robots, but do not require physical environment marks such as pheromones. Instead, these algorithms rely on simple, local, low bandwidth, direct communication between robots. We describe the algorithms and measure their performance in worlds with and without obstacles.Engineering and Applied Science

    Updated guidelines, updated curriculum: The GAISE College Report and introductory statistics for the modern student

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    Since the 2005 American Statistical Association's (ASA) endorsement of the Guidelines for Assessment and Instruction in Statistics Education (GAISE) College Report, changes in the statistics field and statistics education have had a major impact on the teaching and learning of statistics. We now live in a world where "Statistics - the science of learning from data - is the fastest-growing science, technology, engineering, and math (STEM) undergraduate degree in the United States," according to the ASA, and where many jobs demand an understanding of how to explore and make sense of data. In light of these new reports and other changes and demands on the discipline, a group of volunteers revised the 2005 GAISE College Report. The updated report was endorsed by the Board of Directors of the American Statistical Association in July 2016. To help shed additional light on the revision process and subsequent changes in the report, we review the report and share insights into the committee's thoughts and assumptions.Comment: in press, CHANC

    Kinetics of substrate oxidation and hydrogen peroxide production by Mycoplasma mycoides subsp. mycoides Large Colony (LC) type and Mycoplasma mycoides subsp. capri

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    Mycoplasma mycoides subsp. mycoides Large Colony (LC) type is a pathogen of goats causing contagious agalactia and respiratory disease, found on all continents where small ruminants are kept. It shares close genetic characteristics with M. mycoides subsp. capri. Substrate oxidation by 22 strains of M. mycoides subsp. mycoides LC from nine countries was compared with that of eight strains of M. mycoides subsp. capri from five countries. There was considerable similarity in the substrates used, but substrate saturation coefficients (Ks) varied for different substrates. Substrate utilization patterns and Ks values did not (1) significantly differentiate the LC strains from each other, (2) show any correlation with geographical origin, or (3) distinguish the LC strains from the capri strains. These results support previous studies justifying the reclassification of these subspecies as a single species

    Utility of the new Movement Disorder Society clinical diagnostic criteria for Parkinson's disease applied retrospectively in a large cohort study of recent onset cases

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    Objective: To examine the utility of the new Movement Disorder Society (MDS) diagnostic criteria in a large cohort of Parkinson's disease (PD) patients. Methods: Recently diagnosed (<3.5 years) PD cases fulfilling United Kingdom (UK) brain bank criteria in Tracking Parkinson's, a UK multicenter prospective natural history study were assessed by retrospective application of the MDS criteria. Results: In 2000 cases, 1835 (91.7%) met MDS criteria for PD, either clinically established (n = 1261, 63.1%) or clinically probable (n = 574, 28.7%), leaving 165 (8.3%) not fulfilling criteria. Clinically established cases were significantly more likely to have limb rest tremor (89.3%), a good l-dopa response (79.5%), and olfactory loss (71.1%), than clinically probable cases (60.6%, 44.4%, and 34.5% respectively), but differences between probable PD and ‘not PD’ cases were less evident. In cases not fulfilling criteria, the mean MDS UPDRS3 score (25.1, SD 13.2) was significantly higher than in probable PD (22.3, SD 12.7, p = 0.016) but not established PD (22.9, SD 12.0, p = 0.066). The l-dopa equivalent daily dose of 341 mg (SD 261) in non-PD cases was significantly higher than in probable PD (250 mg, SD 214, p < 0.001) and established PD (308 mg, SD 199, p = 0.025). After 30 months' follow-up, 89.5% of clinically established cases at baseline remained as PD (established/probable), and 86.9% of those categorized as clinically probable at baseline remained as PD (established/probable). Cases not fulfilling PD criteria had more severe parkinsonism, in particular relating to postural instability, gait problems, and cognitive impairment. Conclusion: Over 90% of cases clinically diagnosed as early PD fulfilled the MDS criteria for PD. Those not fulfilling criteria may have an atypical parkinsonian disorder or secondary parkinsonism that is not correctly identified by the UK Brain Bank criteria, but possibly by the new criteria

    Evaluasi Program Pembelajaran Bahasa Inggris

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    The aims of this research were to evaluate English learning in context, input, process, product. This research was an evaluation research. The sources of the research were students of English for Children class at English Smart Bandar Jaya. The data was collected through observation, test, and documentation which was analyzed descriptive quantitative. The conclusions in this research were : 1) the of context value of sub component at the pre-condition is fair, the input value of component sub component infrastructure,human resources and curriculum is poor, the result of process component sub component of planning and english learning implementation is fair, and the product component value in the learning result of the students is fair, and 2) the recommendation of this research,the general manager needs to observe and change the curriculum for a better future, then provide laboratory room for listening, the teachers should make a lesson plan based on the syllabus for each competency.Penelitian ini bertujuan untuk mengevaluasi pembelajaran Bahasa Inggris pada komponen context, input, process, product. Penelitian ini merupakan penelitian evaluasi. Sumber penelitian adalah pembelajar kelas English for Children di English Smart Bandar Jaya. Data dikumpulkan dengan observasi, tes dan dokumentasi kemudian dianalisis secara deskriptif kuantitatif. Kesimpulan dalam penelitian ini : 1) nilai context sub komponen kondisi awal lembaga cukup, nilai input sub komponen fasilitas sarana prasarana, tenaga pendidik dan kurikulum cukup, nilai process sub komponen perencanaan dan pelaksanaan pembelajaran bahasa Inggris kurang, dan nilai komponen product pada hasil belajar pembelajar cukup, dan 2) rekomendasi penelitian ini, kepala lembaga perlu meninjau atau mengubah kurikulum lembaga untuk pembaruan ke arah yang lebih baik, disediakan ruang laboratorium untuk menunjang pembelajaran listening, tentor harus membuat lesson plan yang disusun berdasarkan silabus unit kompetensi
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