404 research outputs found
Collapse of Flexible Polyelectrolytes in Multivalent Salt Solutions
The collapse of flexible polyelectrolytes in a solution of multivalent
counterions is studied by means of a two state model. The states correspond to
rod-like and spherically collapsed conformations respectively. We focus on the
very dilute monomer concentration regime where the collapse transition is found
to occur when the charge of the multivalent salt is comparable (but smaller) to
that of the monomers. The main contribution to the free energy of the collapsed
conformation is linear in the number of monomers , since the internal state
of the collapsed polymer approaches that of an amorphous ionic solid. The free
energy of the rod-like state grows as , due to the electrostatic energy
associated with that shape. We show that practically all multivalent
counterions added to the system are condensed into the polymer chain, even
before the collapse.Comment: LaTeX-revtex, psfig file, 4 figure
FPGA based data acquisition system for COMPASS experiment
This paper discusses the present data acquisition system (DAQ) of the COMPASS
experiment at CERN and presents development of a new DAQ. The new DAQ must
preserve present data format and be able to communicate with FPGA cards. Parts
of the new DAQ are based on state machines and they are implemented in C++ with
usage of the QT framework, the DIM library, and the IPBus technology. Prototype
of the system is prepared and communication through DIM between parts was
tested. An implementation of the IPBus technology was prepared and tested. The
new DAQ proved to be able to fulfill requirements.Comment: 8 pages, CHEP 201
Pneumococcal vaccination coverage among children with sickle cell anemia, sickle cell trait, and normal hemoglobin
BackgroundChildren with sickle cell anemia and sickle cell trait are at an increased risk of invasive pneumococcal disease compared to children with normal hemoglobin. We assessed and compared pneumococcal vaccination status among these three groups.ProcedureChildren with sickle cell anemia and sickle cell trait were identified using Michigan newborn screening records (1997â2014); each child was matched to four children with normal hemoglobin based on age, Medicaid enrollment (at least 1 year from 2012â2014), race, and census tract. Vaccination records were obtained from the stateâs immunization system. Pneumococcal vaccine coverage (PCV7 or PCV13 depending on date of administration) was assessed at milestone ages of 3, 5, 7, and 16 months. The proportion of children with vaccine coverage at each milestone was calculated overall and compared among children with sickle cell anemia, sickle cell trait, and normal hemoglobin using chiâsquare tests.ResultsThe study population consisted of 355 children with sickle cell anemia, 17,319 with sickle cell trait, and 70,757 with normal hemoglobin. The proportion of children with ageâappropriate pneumococcal vaccination coverage was low at each milestone and generally decreased over time. Children with sickle cell anemia were more likely to be covered compared to children with sickle cell trait or normal hemoglobin.ConclusionsDespite higher pneumococcal vaccination coverage among children with sickle cell anemia, opportunities for improvement exist among all children. Targeted interventions will benefit from mechanisms to identify children with increased risks such as sickle cell anemia or trait to improve pneumococcal vaccination coverage among these groups.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145560/1/pbc27282.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145560/2/pbc27282_am.pd
Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives
Recent theoretical and experimental studies highlight the possibility of new
fundamental particle physics beyond the Standard Model that can be probed by
sub-eV energy experiments. The OSQAR photon regeneration experiment looks for
"Light Shining through a Wall" (LSW) from the quantum oscillation of optical
photons into "Weakly Interacting Sub-eV Particles" (WISPs), like axion or
axion-like particles (ALPs), in a 9 T transverse magnetic field over the
unprecedented length of m. No excess of events has been
detected over the background. The di-photon couplings of possible new light
scalar and pseudo-scalar particles can be constrained in the massless limit to
be less than GeV. These results are very close to the
most stringent laboratory constraints obtained for the coupling of ALPs to two
photons. Plans for further improving the sensitivity of the OSQAR experiment
are presented.Comment: 7 pages, 7 figure
Hydroxyurea use among children with sickle cell anemia
This study describes hydroxyurea use among children ages 1 to 17 with sickle cell anemia (SCA) enrolled in at least one year of Medicaid in six states from 2005 to 2012. Administrative claims were used to summarize the number of daysâ supply of hydroxyurea dispensed by state and year. A total of 7963 children with SCA contributed 22Â 424 personâyears. Among personâyears with greater than 30 days of hydroxyurea, only 18% received at least 300 days of hydroxyurea, which varied by state. Following updated recommendations for all children with SCA to be offered hydroxyurea, strategies to increase hydroxyurea adherence among this population are needed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149259/1/pbc27721_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149259/2/pbc27721.pd
Rendering an Account: An Open-State Archive in Postgraduate Supervision
The paper begins with a brief account of the transformation of research degree studies under the pressures of global capitalism and neo-liberal governmentality. A parallel transformation is occurring in the conduct of research through the use of information and communication technologies. Yet the potential of ICTs to shape practices of surveillance or to produce new student-supervisor relations and enhance the processes of developing the dissertation has received almost no critical attention. As doctoral supervisor and student, we then describe the features and uses of a web-based open state archive of the student's work-in-progress, developed by the student and accessible to his supervisor. Our intention was to encourage more open conversations between data and theorising, student and supervisor, and ultimately between the student and professional community. However, we recognise that relations of accountability, as these have developed within a contemporary "audit revolution" (Power, 1994, 1997) in universities, create particular "lines of visibility" (Munro, 1996). Thus while the open-state archive may help to redefine in less managerial terms notions of quality, transparency, flexibility and accountability, it might also make possible greater supervisory surveillance. How should we think about the panoptical potential of this archive? We argue that the diverse kinds of interactional patterns and pedagogical intervention it encourages help to create shifting subjectivities. Moreover, the archive itself is multiple, in bringing together an array of diverse materials that can be read in various ways, by following multiple paths. It therefore constitutes a collage, which we identify as a mode of cognition and of accounting distinct from but related to argument and narrative. As a more "open" text (Iser, 1978) it has an indeterminacy which may render it less open to abuse for the technologies of managerial accountability
The Communication Library DIALOG for iFDAQ of the COMPASS Experiment
Modern experiments in high energy physics impose
great demands on the reliability, the efficiency, and the data rate
of Data Acquisition Systems (DAQ). This contribution focuses on
the development and deployment of the new communication library
DIALOG for the intelligent, FPGA-based Data Acquisition System
(iFDAQ) of the COMPASS experiment at CERN. The iFDAQ
utilizing a hardware event builder is designed to be able to readout
data at the maximum rate of the experiment. The DIALOG library is a
communication system both for distributed and mixed environments,
it provides a network transparent inter-process communication layer.
Using the high-performance and modern C++ framework Qt and its
Qt Network API, the DIALOG library presents an alternative to
the previously used DIM library. The DIALOG library was fully
incorporated to all processes in the iFDAQ during the run 2016.
From the software point of view, it might be considered as a
significant improvement of iFDAQ in comparison with the previous
run. To extend the possibilities of debugging, the online monitoring
of communication among processes via DIALOG GUI is a desirable
feature. In the paper, we present the DIALOG library from several
insights and discuss it in a detailed way. Moreover, the efficiency
measurement and comparison with the DIM library with respect to
the iFDAQ requirements is provided
Reviews of theoretical frameworks: challenges and judging the quality of theory application.
Background Rigorous reviews of available information, from a range of resources, is required to support medical and health educators in their decision making related to their educational practice. Aim The aim of the paper is to highlight the importance of a review of theoretical frameworks specifically to supplement reviews that focus on a synthesis of the empirical evidence alone. Establishing a shared understanding of theory as a concept is highlighted as a challenge to these types of review and some practical strategies to achieving this are presented. The paper also introduces the concept of theoretical quality to the methodology of literature reviews, arguing that a critique of how theory is applied should complement the methodological appraisal of the literature in a review. Method We illustrate the challenge of establishing a shared meaning of theory through reference to experiences of an on-going review of this kind conducted in the field of interprofessional education (IPE) and use a high scoring paper selected in this review to illustrate how theoretical quality can be assessed. We focus on theories that apply to IPE curriculum design but the findings are transferable to all reviews of theoretical frameworks. Findings In reaching a shared understanding of theory as a concept, practical strategies that promote experiential and practical ways of knowing (e.g. small group work and piloting of all phases of the review protocol) are required in addition to more propositional ways of sharing knowledge. Concepts of parsimony, testability, operational adequacy and empirical adequacy are explored as concepts that establish theoretical quality. Conclusions Reviews of theoretical frameworks used in medical education are required to inform educational practice. Review teams should make time and effort to reach a shared understanding of the term theory. Theory reviews, and reviews more widely, should add an assessment of theory application to the protocol of their review method.
Synapse-associated protein 102/dlgh3 couples the NMDA receptor to specific plasticity pathways and learning strategies
Understanding the mechanisms whereby information encoded within patterns of action potentials is deciphered by neurons is central to cognitive psychology. The multiprotein complexes formed by NMDA receptors linked to synaptic membrane-associated guanylate kinase (MAGUK) proteins including synapse-associated protein 102 (SAP102) and other associated proteins are instrumental in these processes. Although humans with mutations in SAP102 show mental retardation, the physiological and biochemical mechanisms involved are unknown. Using SAP102 knock-out mice, we found specific impairments in synaptic plasticity induced by selective frequencies of stimulation that also required extracellular signal-regulated kinase signaling. This was paralleled by inflexibility and impairment in spatial learning. Improvement in spatial learning performance occurred with extra training despite continued use of a suboptimal search strategy, and, in a separate nonspatial task, the mutants again deployed a different strategy. Double-mutant analysis of postsynaptic density-95 and SAP102 mutants indicate overlapping and specific functions of the two MAGUKs. These in vivo data support the model that specific MAGUK proteins couple the NMDA receptor to distinct downstream signaling pathways. This provides a mechanism for discriminating patterns of synaptic activity that lead to long-lasting changes in synaptic strength as well as distinct aspects of cognition in the mammalian nervous system
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