6,323 research outputs found

    The effects of weight and physical activity change over 20 years on later-life objective and self-reported disability.

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    Weight and health behaviours are known to affect physical disability; however the evidence exploring the impact of changes to these lifestyle factors over the life course on disability is inconsistent. We aimed to explore the roles of weight and activity change between mid and later life on physical disability

    Conditional q-Entropies and Quantum Separability: A Numerical Exploration

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    We revisit the relationship between quantum separability and the sign of the relative q-entropies of composite quantum systems. The q-entropies depend on the density matrix eigenvalues p_i through the quantity omega_q = sum_i p_i^q. Renyi's and Tsallis' measures constitute particular instances of these entropies. We perform a systematic numerical survey of the space of mixed states of two-qubit systems in order to determine, as a function of the degree of mixture, and for different values of the entropic parameter q, the volume in state space occupied by those states characterized by positive values of the relative entropy. Similar calculations are performed for qubit-qutrit systems and for composite systems described by Hilbert spaces of larger dimensionality. We pay particular attention to the limit case q --> infinity. Our numerical results indicate that, as the dimensionalities of both subsystems increase, composite quantum systems tend, as far as their relative q-entropies are concerned, to behave in a classical way

    Foundations of dynamic learning analytics: Using university student data to increase retention

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    With digitisation and the rise of e-learning have come a range of computational tools and approaches that have allowed educators to better support the learners' experience in schools, colleges and universities. The move away from traditional paper-based course materials, registration, admissions and support services to the mobile, always-on and always accessible data has driven demand for information and generated new forms of data observable through consumption behaviours. These changes have led to a plethora of data sets that store learning content and track user behaviours. Most recently, new data analytics approaches are creating new ways of understanding trends and behaviours in students that can be used to improve learning design, strengthen student retention, provide early warning signals concerning individual students and help to personalise the learner's experience. This paper proposes a foundational learning analytics model (LAM) for higher education that focuses on the dynamic interaction of stakeholders with their data supported by visual analytics, such as self-organising maps, to generate conversations, shared inquiry and solution-seeking. The model can be applied for other educational institutions interested in using learning analytics processes to support personalised learning and support services. Further work is testing its efficacy in increasing student retention rates

    Optimising the radiolabelling properties of technetium tricarbonyl and His-tagged proteins

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    BACKGROUND: To date, the majority of protein-based radiopharmaceuticals have been radiolabelled using non-site-specific conjugation methods, with little or no control to ensure retained protein function post-labelling. The incorporation of a hexahistidine sequence (His-tag) in a recombinant protein can be used to site-specifically radiolabel with 99mTc-tricarbonyl ([99mTc(CO)3]+). This chemistry has been made accessible via a technetium tricarbonyl kit; however, reports of radiolabelling efficiencies and specific activities have varied greatly from one protein to another. Here, we aim to optimise the technetium tricarbonyl radiolabelling method to produce consistently &gt;95% radiolabelling efficiencies with high specific activities suitable for in vivo imaging.METHODS: Four different recombinant His-tagged proteins (recombinant complement receptor 2 (rCR2) and three single chain antibodies, α-CD33 scFv, α-VCAM-1 scFv and α-PSMA scFv), were used to study the effect of kit volume, ionic strength, pH and temperature on radiolabelling of four proteins.RESULTS: We used 260 and 350 μL [99mTc(CO)3]+ kits enabling us to radiolabel at higher [99mTc(CO)3]+ and protein concentrations in a smaller volume and thus increase the rate at which maximum labelling efficiency and specific activity were reached. We also demonstrated that increasing the ionic strength of the reaction medium by increasing [Na+] from 0.25 to 0.63 M significantly increases the rate at which all four proteins reach a &gt;95% labelling efficiency by at least fourfold, as compared to the conventional IsoLink® kit (Covidien, Petten, The Netherlands) and 0.25 M [Na+].CONCLUSION: We have found optimised kit and protein radiolabelling conditions suitable for the reproducible, fast, efficient radiolabelling of proteins without the need for post-labelling purification.</p

    A Decomposed Fourier-Motzkin Elimination Framework to Derive Vessel Capacity Models

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    Accurate Vessel Capacity Models (VCMs) expressing thetrade-off between different container types that can be stowed on containervessels are required in core liner shipping functions such as uptake-,capacity-, and network management. Today, simple models based on volume,weight, and refrigerated container capacity are used for these tasks,which causes overestimations that hamper decision making. Though previouswork on stowage planning optimization in principle provide finegrainedlinear Vessel Stowage Models (VSMs), these are too complexto be used in the mentioned functions. As an alternative, this papercontributes a novel framework based on Fourier-Motzkin Eliminationthat automatically derives VCMs from VSMs by projecting unneededvariables. Our results show that the projected VCMs are reduced byan order of magnitude and can be solved 20–34 times faster than theircorresponding VSMs with only a negligible loss in accuracy. Our frameworkis applicable to LP models in general, but are particularly effectiveon block-angular structured problems such as VSMs. We show similarresults for a multi-commodity flow problem

    WFPC2 Observations of the Hubble Deep Field-South

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    The Hubble Deep Field-South observations targeted a high-galactic-latitude field near QSO J2233-606. We present WFPC2 observations of the field in four wide bandpasses centered at roughly 300, 450, 606, and 814 nm. Observations, data reduction procedures, and noise properties of the final images are discussed in detail. A catalog of sources is presented, and the number counts and color distributions of the galaxies are compared to a new catalog of the HDF-N that has been constructed in an identical manner. The two fields are qualitatively similar, with the galaxy number counts for the two fields agreeing to within 20%. The HDF-S has more candidate Lyman-break galaxies at z > 2 than the HDF-N. The star-formation rate per unit volume computed from the HDF-S, based on the UV luminosity of high-redshift candidates, is a factor of 1.9 higher than from the HDF-N at z ~ 2.7, and a factor of 1.3 higher at z ~ 4.Comment: 93 pages, 25 figures; contains very long table

    Evaluation of a School Systems Plan to Utilize Teachers’ Perceptions of Principal Leadership to Improve Student Achievement

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    This study examines fourth grade student achievement in relation to teacher perceptions of principal leadership and other selected variables in a large urban school district in Georgia. Student achievement was measured by performance on the Georgia Criterion-Referenced Competency Tests (CRCT) during the 2004-05 and 2005-06 school years. The leadership instrument measures six competencies: (I) Instructional Leadership, (II) Interpersonal Skills, (III) Decision-making Skills, (IV) Facilities Planning Skills and Student Behavior Expectations, (V) Evaluation, and (VI) School Climate. The sample consisted of 3,900 teachers from 81 schools in the district. Demographic variables for each school included enrollment, free/reduced lunch eligibility, discipline incidents, retained students, absenteeism, teacher experience, administrator experience, principal gender, and principal tenure.Pearson correlation analyses indicated the following significant relationships:(a) student achievement with discipline incidents, free/reduced lunch participants, and school climate; (b) school climate with principals’ instructional leadership, interpersonal skills, decision-making, facilities planning and student behavior expectations, evaluation, discipline incidents, retained students, enrollment, and free/reduced lunch participants. Regression analyses indicated that: (a) student achievement was inversely explained by discipline incidents, but none of the other variables and (b) discipline incidents were explained by enrollment, absenteeism, retained students, principal tenure, teacher experience, and free/reduced lunch status

    MACK the Bulldog Mural at Bulldog QuikSnak

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    MACK the Bulldog mural by Ed Williams hanging at the Bulldog QuikSnak grill in Boiling Springs, NC.https://digitalcommons.gardner-webb.edu/gardner-webb-bulldog-mascot/1012/thumbnail.jp
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