1,671 research outputs found
Development of a steady state model for forecasting U.S. Navy Nurse Corps personnel
This thesis developed a deterministic Markov state model to provide the U.S. Navy Nurse Corps a tool to more accurately forecast recruiting goals and future years force structure. Nurse Corps data was provided by the Nurse Corps Community Manager's office covering fiscal years 1990 to 2003. The probabilities used in the Markov model were derived from the fiscal year data. Transitions used in this model were stay at present grade, move up one grade or exit the system. Backward movement was not allowed and individuals could only move up one grade per year. The model was limited to eleven years and focused primarily on the ranks of O-1 to O-3. O-4's and O-5's that appeared in the data were allowed to flow through the system. Logistic regression was then used to investigate the probability of "staying" in the Nurse Corps to certain career decision points. Nurse Corps cohort data files for fiscal years 90 through 94 were merged for analysis, as was cohort data for fiscal year 96 through 98. Results of the markov model show that the O-1's and O-2's reach a steady state at the eight-year mark while the O-3's reach a steady state at the seventeen-year mark (based on provided data). The steady state values are compared to actual Nurse Corps goals. Results of the logistic regression show that Recalls, Medical Enlisted Commissioning Program and Nurse Candidate Program were all significant at increasing the probability of staying in the Nurse Corps. Males were more likely than females to stay in the Nurse Corps and changes in education levels decreased the probability of staying in the Nurse Corps.http://archive.org/details/developmentofste109451699Lieutenant, United States NavyApproved for public release; distribution is unlimited
Marsviewer 2008
Marsviewer 2008 is designed for quality control, browsing, and operational and science analysis of images and derived image products returned by spacecraft. This program allows all derived products (reduced data records, or RDRs) associated with each original image (experiment data record, or EDR) to be viewed in various ways, including in stereo, depending on the type of image
Scale-adaptive simulation of a square cross-sectional bubble column
This paper presents detailed Euler–Euler Scale-Adaptive Simulations of the dispersed bubbly flow in a square cross-sectioned bubble column. The main objective is to investigate the potential of this approach for the prediction of bubbly flows with anisotropic liquid velocity fluctuations. The set of physical models describing the momentum exchange between the phases was chosen according to previous experiences of the authors. Experimental data and Euler–Euler Large Eddy Simulation are used for comparison. It was found that the presented combination of sub-models provides good agreement with experimental data for the mean flow and liquid velocity fluctuations. The energy spectra of the resolved velocity obtained from the simulations are presented and compared to the experimental spectra
Experimental Proof of a Magnetic Coulomb Phase
Spin ice materials are magnetic substances in which the spin directions map
onto hydrogen positions in water ice. Recently this analogy has been elevated
to an electromagnetic equivalence, indicating that the spin ice state is a
Coulomb phase, with magnetic monopole excitations analogous to ice's mobile
ionic defects. No Coulomb phase has yet been proved in a real magnetic
material, as the key experimental signature is difficult to resolve in most
systems. Here we measure the scattering of polarised neutrons from the
prototypical spin ice Ho2Ti2O7. This enables us to separate different
contributions to the magnetic correlations to clearly demonstrate the existence
of an almost perfect Coulomb phase in this material. The temperature dependence
of the scattering is consistent with the existence of deconfined magnetic
monopoles connected by Dirac strings of divergent length.Comment: 18 pages, 4 fig
Utilising inorganic nanocarriers for gene delivery
The delivery of genetic materials into cells to elicit cellular responses has been extensively studied by biomaterials scientists globally. Many materials such as lipids, peptides, viruses, synthetically modified cationic polymers and certain inorganic nanomaterials could be used to complex the negatively charged plasmids and deliver the formed package into cells. The recent literature on the delivery of genetic materials utilising inorganic nanoparticles is carefully examined in this review. We have picked out the most relevant references and concisely summarised the findings with illustrated examples. We further propose alternative approaches and suggest future pathways towards the practical use of multifunctional nanocarriers
Artesunate reduces but does not prevent posttreatment transmission of Plasmodium falciparum to Anopheles gambiae.
Combination therapy that includes artemisinin derivatives cures most falciparum malaria infections. Lowering transmission by reducing gametocyte infectivity would be an additional benefit. To examine the effect of such therapy on transmission, Gambian children with Plasmodium falciparum malaria were treated with standard regimens of chloroquine or pyrimethamine-sulfadoxine alone or in combination with 1 or 3 doses of artesunate. The infectivity to mosquitoes of gametocytes in peripheral blood was determined 4 or 7 days after treatment. Infection of mosquitoes was observed in all treatment groups and was positively associated with gametocyte density. The probability of transmission was lowest in those who received pyrimethamine-sulfadoxine and 3 doses of artesunate, and it was 8-fold higher in the group that received pyrimethamine-sulfadoxine alone. Artesunate reduced posttreatment infectivity dramatically but did not abolish it completely. The study raises questions about any policy to use pyrimethamine-sulfadoxine alone as the first-line treatment for malaria
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