Design of central irradiation facilities for the MITR-II research reactor

"September 1976."Also issued as a Ph. D. thesis by the first author and supervised by the second author, MIT Dept. of Nuclear Engineering, 1977Includes bibliographical references (pages 94-95)Design analysis studies have been made for various in-core irradiation facility designs which are presently used, or proposed for future use in the MITR-II. The information obtained includes reactivity effects, core flux and power distributions, and estimates of the safety limits and limiting conditions for operation. A finite-difference, diffusion theory computer code was employed in two and three dimensions, and with three and fifteen group energy schemes. The facilities investigated include the single-element molybdenum sample holder, a proposed double-element irradiation facility and a proposed central irradiation facility design encompassing most of the area of the three central core positions. In addition, a comparison of the effects of various absorber materials has been made for a core configuration which includes three solid dummies. Flux levels in the molybdenum holder facility and in the beam ports were calculated for both three and five dummy cores. Flooding the sample tube in these cases was found to increase the safety and operating limits, but not to unacceptable levels for an 8 inch blade height. For the five dummy case, the operating limit in the C-ring was predicted to reach its maximum allowed value at a blade bank height of 13.6 inches. The reactivity effect of flooding was calculated to be 0.19%AK for the five dummy case, in direct agreement with the measured value. Flooging the large sample channel in the double element facility was found to increase the reactivity by 1.5 6%AK ff and also to cause an unacceptable power-peaking. The proposed central irradiation facility is a thermal flux-trap which could produce thermal flux values of up to 2.0 x 1014 n/cm 2 sec. Computer estimates show that flooding this facility's central sample tube would increase this value to 2.5 x 1014 n/cm2 sec, without resulting in an unacceptable power peak

Supporting Peer Help and Collaboration in Distributed Workplace Environments

Special Issue on Computer Supported Collaborative LearningIncreasingly, organizations are geographically distributed with activities coordinated and integrated through the use of information technology. Such organizations face constant change and the corresponding need for continual learning and renewal of their workers. In this paper we describe a prototype system called PHelpS (Peer Help System) that facilitates workers in carrying out such "life long learning". PHelpS supports workers as they perform their tasks, offers assistance in finding peer helpers when required, and mediates communication on task-related topics. When a worker runs into difficulty in carrying out a task, PHelpS provides a list of other workers who are ready, willing and able to help him or her. The worker then selects a particular helper with PHelpS supporting the subsequent help interaction. The PHelpS system acts as a facilitator to stimulate learning and collaboration, rather than as a directive agent imposing its perspectives on the workers. In this way PHelpS facilitates the creation of extensive informal peer help networks, where workers help one another with tasks and opens up new research avenues for further exploration of AI-based computer-supported collaborative learning. (http://aied.inf.ed.ac.uk/members98/archive/vol_9/greer/full.html

The successful Ghana election of 2008: a convenient myth?

Ghana's 2008 election has been hailed by national and international observers as a model for Africa. The perception of success has prevailed despite persistent concerns about an inflated voters' register and electoral fraud perpetrated by the two major parties, the NPP and NDC, in their strongholds in the Ashanti and Volta Regions respectively. Electoral malpractice in Ghana's virtual two-party system could acquire a decisive importance as a ‘third force’, representing an even more important factor than the smaller opposition parties. Unfortunate diplomatic and technocratic biases in election monitoring, combined with a reluctance on the part of the responsible authorities to investigate what appears to be a long history of fraudulent voting, amounts to a dangerous time bomb of unresolved conflict which could detonate in future elections

cGMP Recombinant FIX for IV and Oral Hemophilia B Therapy

Three specific aims are proposed: Specific Aim # 1. Process engineer and scale-up the recovery and purification of transgenic recombinant human Factor IX. The University of Nebraska-Lincoln Biological Process Development Facility will complete process development and scale-up, and produce clinical grade materials for preclinical studies. The endpoint is a proposed final product specification to help facilitate transfer to current Good Manufacturing Practices compliant production of clinical grade material to support an Investigational New Drug filing with the United States Food and Drug Administration (FDA) leading to clinical trials. Specific Aim #2. Characterize and formulate transgenic recombinant human Factor IX for intravenous dosage, and evaluate in a hemophilia B dog model. These activities are directed toward characterization of the product important to assure the provision of safe and reproducibly effective hemostasis. The results of these investigations will help support an IND filing with the FDA. Specific Aim # 3. Develop an oral dosage form of transgenic recombinant human Factor IX, and evaluate in hemophilia B mice and dog models. Oral administration of coagulation therapy will obviate the invasiveness, discomfort, potential for opportunistic infection, and complications of storage and supplies that accompany intravenous administration. Oral dosage forms of Factor IX will thus greatly increase the proportion of the patient population that can be treated. There is also published evidence suggesting that oral administration may reduce the potential for complicating immune responses to replacement therapy, especially in patients with severe hemophilia

Design of central irradiation facilities for the MITR-II research reactor.

Thesis. 1977. M.S.--Massachusetts Institute of Technology. Dept. of Nuclear Engineering.MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.Includes bibliographical references.M.S

Conceptualising a model to guide nursing and midwifery in the community guided by an evidence review

Background: Successful models of nursing and midwifery in the community delivering healthcare throughout the lifespan and across a health and illness continuum are limited, yet necessary to guide global health services. Primary and community health services are the typical points of access for most people and the location where most care is delivered. The scope of primary healthcare is complex and multifaceted and therefore requires a practice framework with sound conceptual and theoretical underpinnings. The aim of this paper is to present a conceptual model informed by a scoping evidence review of the literature. Methods: A scoping evidence review of the literature was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Databases included CINAHL, MEDLINE, PsycINFO and SocINDEX using the EBSCO platform and the Cochrane Library using the keywords: model, nursing, midwifery, community, primary care. Grey literature for selected countries was searched using the Google ‘advanced’ search interface. Data extraction and quality appraisal for both empirical and grey literature were conducted independently by two reviewers. From 127 empirical and 24 non-empirical papers, data extraction parameters, in addition to the usual methodological features, included: the nature of nursing and midwifery; the population group; interventions and main outcomes; components of effective nursing and midwifery outcomes. Results: The evidence was categorised into six broad areas and subsequently synthesised into four themes. These were not mutually exclusive: (1) Integrated and Collaborative Care; (2) Organisation and Delivery of Nursing and Midwifery Care in the Community; (3) Adjuncts to Nursing Care and (4) Overarching Conceptual Model. It is the latter theme that is the focus of this paper. In essence, the model depicts a person/client on a lifespan and preventative-curative trajectory. The health related needs of the client, commensurate with their point position, relative to both trajectories, determines the nurse or midwife intervention. Consequently, it is this need, that determines the discipline or speciality of the nurse or midwife with the most appropriate competencies. Conclusion: Use of a conceptual model of nursing and midwifery to inform decision-making in primary/community based care ensures clinical outcomes are meaningful and more sustainable. Operationalising this model for nursing and midwifery in the community demands strong leadership and effective clinical governance

Atmospheric and Astrophysical Neutrinos above 1 TeV Interacting in IceCube

The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV--PeV) neutrinos produced in distant astrophysical objects. A search for $\gtrsim 100$~TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos. At lower energies, IceCube collects large numbers of neutrinos from the weak decays of mesons in cosmic-ray air showers. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1~TeV and 1~PeV in 641 days of data taken from 2010--2012, lowering the energy threshold for neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis. Astrophysical neutrinos remain the dominant component in the southern sky down to 10 TeV. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum, $\Phi_{\nu} = 2.06^{+0.4}_{-0.3} \times 10^{-18} \left({E_{\nu}}/{10^5 \,\, \rm{GeV}} \right)^{-2.46 \pm 0.12} {\rm {GeV^{-1} \, cm^{-2} \, sr^{-1} \, s^{-1}} }$, as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere, 1.52 times the benchmark theoretical prediction used in previous IceCube results at 90\% confidence.Comment: 18 pages, 12 figure

Improved limits on dark matter annihilation in the Sun with the 79-string IceCube detector and implications for supersymmetry

We present an improved event-level likelihood formalism for including neutrino telescope data in global fits to new physics. We derive limits on spin-dependent dark matter-proton scattering by employing the new formalism in a re-analysis of data from the 79-string IceCube search for dark matter annihilation in the Sun, including explicit energy information for each event. The new analysis excludes a number of models in the weak-scale minimal supersymmetric standard model (MSSM) for the first time. This work is accompanied by the public release of the 79-string IceCube data, as well as an associated computer code for applying the new likelihood to arbitrary dark matter models.Comment: 24 pages, 8 figs, 1 table. Contact authors: Pat Scott & Matthias Danninger. Likelihood tool available at http://nulike.hepforge.org. v2: small updates to address JCAP referee repor