Analysis of the effectiveness of ground-based VLF wave observations for predicting or nowcasting relativistic electron flux at geostationary orbit

Post-storm relativistic electron flux enhancement at geosynchronous orbit has shown correlation with very low frequency (VLF) waves measured by satellite in situ. However, our previous study found little correlation between electron flux and VLF measured by a ground-based instrument at Halley, Antarctica. Here we explore several possible explanations for this low correlation. Using 220 storms (1992–2002), our previous work developed a predictive model of the post-storm flux at geosynchronous orbit based on explanatory variables measured a day or two before the flux increase. In a nowcast model, we use averages of variables from the time period when flux is rising during the recovery phase of geomagnetic storms, and limit the VLF (1.0 kHz) measure to the dawn period at Halley (9–12 UT). This improves the simple correlation of VLF wave intensity with flux, although the VLF effect in an overall multiple regression is still much less than that of other factors. When analyses are performed separately for season and IMF Bz orientation, VLF outweighs the influence of other factors only during winter months when IMF Bz is in an average northward orientation

Prediction of relativistic electron flux at geostationary orbit following storms: Multiple regression analysis

Many solar wind and magnetosphere parameters correlate with relativistic electron flux following storms. These include relativistic electron flux before the storm, seed electron flux, solar wind velocity and number density (and their variation), IMF Bz, AE and Kp indices, and ultra low frequency (ULF) and very low frequency (VLF) wave power. However, as all these variables are intercorrelated, we use multiple regression analyses to determine which are the most predictive of flux when other variables are controlled. Using 219 storms (1992-2002), we obtained hourly averaged electron fluxes for outer radiation belt relativistic electrons (>1.5 MeV) and seed electrons (100 keV) from LANL spacecraft (geosynchronous orbit). For each storm, we found the log10 maximum relativistic electron flux 48-120 hours after the end of the main phase of each storm. Each predictor variable was averaged over the 12 hours before the storm, main phase, and the 48 hours following minimum Dst. High levels of flux following storms are best modeled by a set of variables. In decreasing influence, ULF, seed electron flux, Vsw and its variation, and after-storm Bz were the most significant explanatory variables. Kp can be added to the model, but it adds no further explanatory power. Although we included ground-based VLF power from Halley, Antarctica, it shows little predictive ability. We produced predictive models using the coefficients from the regression models, and assessed their effectiveness in predicting novel observations. The correlation between observed values and those predicted by these empirical models ranged from .645 to .795

Phase transition in a spatial Lotka-Volterra model

Spatial evolution is investigated in a simulated system of nine competing and mutating bacterium strains, which mimics the biochemical war among bacteria capable of producing two different bacteriocins (toxins) at most. Random sequential dynamics on a square lattice is governed by very symmetrical transition rules for neighborhood invasion of sensitive strains by killers, killers by resistants, and resistants by by sensitives. The community of the nine possible toxicity/resistance types undergoes a critical phase transition as the uniform transmutation rates between the types decreases below a critical value $P_c$ above which all the nine types of strain coexist with equal frequencies. Passing the critical mutation rate from above, the system collapses into one of the three topologically identical states, each consisting of three strain types. Of the three final states each accrues with equal probability and all three maintain themselves in a self-organizing polydomain structure via cyclic invasions. Our Monte Carlo simulations support that this symmetry breaking transition belongs to the universality class of the three-state Potts model.Comment: 4 page

Holstein model in infinite dimensions at half-filling

The normal state of the Holstein model is studied at half-filling in infinite dimensions and in the adiabatic regime. The dynamical mean-field equations are solved using perturbation expansions around the extremal paths of the effective action for the atoms. We find that the Migdal-Eliashberg expansion breaks down in the metallic state if the electron-phonon coupling $\lambda$ exceeds a value of about 1.3 in spite of the fact that the formal expansion parameter $\lambda \omega_0/E_F$ ($\omega_0$ is the phonon frequency, $E_F$ the Fermi energy) is much smaller than 1. The breakdown is due to the appearance of more than one extremal path of the action. We present numerical results which illustrate in detail the evolution of the local Green's function, the self-energy and the effective atomic potential as a function of $\lambda$.Comment: Revtex + 17 postscript figures include

Loop B is a major structural component of the 5-HT3 receptor

The 5-HT3 receptor belongs to a family of therapeutically important neurotransmitter-gated receptors whose ligand binding sites are formed by the convergence of six peptide loops (A-F). Here we have mutated 15 amino acid residues in and around loop B of the 5-HT3 receptor (Ser-177 to Asn-191) to Ala or a residue with similar chemical properties. Changes in [3H]granisetron binding affinity (Kd) and 5-HT EC50 were determined using receptors expressed in human embryonic kidney 293 cells. Substitutions at all but one residue (Thr-181) altered or eliminated binding for one or both mutants. Receptors were nonfunctional or EC50 values were altered for all but two mutants (S182T, I190L). Homology modeling indicates that loop B contributes two residues to a hydrophobic core that faces into the β-sandwich of the subunit, and the experimental data indicate that they are important for both the structure and the function of the receptor. The models also show that close to the apex of the loop (Ser-182 to Ile-190), loop B residues form an extensive network of hydrogen bonds, both with other loop B residues and with adjacent regions of the protein. Overall, the data suggest that loop B has a major role in maintaining the structure of the region by a series of noncovalent interactions that are easily disrupted by amino acid substitutions

Global priorities for reduction of cetacean bycatch. Scientific Committee document SC/56/BC2, International Whaling Commission, July 2004, Sorrento, Italy

Progress at reducing the scale and conservation impact of cetacean bycatch has been slow, sporadic and limited to a few specific fisheries or circumstances. As a result bycatch remains perhaps the greatest immediate and well-documented threat to cetacean populations globally. Having recognized the critical importance of reducing bycatch levels to prevent the depletion, and in some cases extinction, of cetacean populations, World Wildlife Fund-US launched a global bycatch initiative early in 2002. Their strategy calls on governmental and non-governmental bodies to move quickly, cooperatively and thoughtfully to achieve bycatch reduction. As a supportive step a working group was established to identify priorities and provide guidance on how financial and other resources should be invested to address bycatch issues. The group will conduct a global survey of cetacean bycatch problems, classify and rank those problems according to an agreed set of criteria and provide a clear rationale for each problem assigned high priority for funding and intervention. The working group will emphasise: (1) situations that are especially critical (e.g. a species’ or population’s survival is immediately at risk from bycatch) and are not being addressed adequately; (2) circumstances where rapid progress could be made with a modest investment of resources; (3) situations in which bycatch is believed to pose a threat to cetaceans but a quantitative assessment is needed to verify the risk; and (4) fisheries in which a currently available solution (technical, socioeconomic or a combination) appears feasible. The report of the working group will be directed at governmental decision makers, aid agencies, nongovernmental organizations and related audiences

Global priorities for reduction of cetacean bycatch

Progress at reducing the scale and conservation impact of cetacean bycatch has been slow, sporadic, and limited to a few specific fisheries or circumstances. As a result, bycatch remains perhaps the greatest immediate and well-documented threat to cetacean populations globally. Having recognized the critical importance of reducing bycatch levels to prevent the depletion, and in some cases extinction, of cetacean populations, World Wildlife Fund-US launched a global bycatch initiative early in 2002. Their strategy calls on governmental and non-governmental bodies to move quickly, cooperatively, and thoughtfully to achieve bycatch reduction. As a supportive step, a working group was established to identify priorities and provide guidance on how financial and other resources should be invested to address bycatch issues. The group conducted a global survey of cetacean bycatch problems and identified a series of specific problems that should be addressed as priorities, with emphasis on: (1) situations that are especially critical (e.g. a species’ or population’s survival is immediately at risk from bycatch) and are not being addressed adequately; (2) circumstances where rapid progress could be made with a modest investment of resources; (3) situations in which bycatch is believed to pose a threat to cetaceans but a quantitative assessment is needed to verify the risk; and (4) fisheries in which a currently available solution (technical, socio-economic, or a combination) appears feasible

Metacognition and lifelong e-learning: a contextual and cyclical process

Metacognition is arguably an important conceptualisation within the area of lifelong e- learning, with many theorists and practitioners claiming that it enhances the learning process. However, the lifelong, cyclical and flexible aspects of 'before', 'during' and 'after' metacognitions within lifelong e-learning (inclusive of whether an 'input' necessarily leads to a completed 'output') seem marginal within current areas of practical and theoretical debate. This article analyses Reeves's (1997) model of web-based learning in the context of the ADAPT project; a study of lifelong learners based in small and medium sized enterprises. The article focuses upon an analysis of this model's view of metacognition, and in the light of the project findings and literature review, aims to put forward an extended and expanded version of the model with reference to lifelong e-learnin

The Spinel LiCoMnO4: 5V cathode and conversion anode

LiCoMnO4 was made at 550 °C in 2 h using a novel biotemplating synthetic methodology. High temperature heat treatment under flowing N2 was then used to prepare the cation-disordered rock salt, LiCoMnO3. We demonstrate for the first time that both phases can operate as conversion anodes in lithium-ion batteries, operating at ~ 0.7 V with specific capacities of ~ 400 mAh g-1. We also demonstrate that 1,3-propane sultone can be used as an electrolytic additive to provide a modest boost to specific capacity in cells cycled at high potentials with LiCoMnO4 as the cathode

The effect of the SAFE or SORRY? programme on patient safety knowledge of nurses in hospitals and nursing homes: a cluster randomised trial

Background: patients in hospitals and nursing homes are at risk for the development of often preventable adverse events. Guidelines for the prevention of many types of adverse events are available, however compliance with these guidelines appears to be lacking. As a result many patients do not receive appropriate care. We developed a patient safety program that allows organisations to implement multiple guidelines simultaneously and therefore facilitates guideline use to improve patient safety. This program was developed for three frequently occurring nursing care related adverse events: pressure ulcers, urinary tract infections and falls. For the implementation of this program we developed educational activities for nurses as a main implementation strategy.Objectives: the aim of this study is to describe the effect of interactive and tailored education on the knowledge levels of nurses.Design: a cluster randomised trial was conducted between September 2006 and July 2008.Settings: ten hospital wards and ten nursing home wards participated in this study. Prior to baseline, randomisation of the wards to an intervention or control group was stratified for centre and type of ward.Participants: all nurses from participating wards.Methods: a knowledge test measured nurses’ knowledge on the prevention of pressure ulcers, urinary tract infections and falls, during baseline en follow-up. The results were analysed for hospitals and nursing homes separately.Results: after correction for baseline, the mean difference between the intervention and the control group on hospital nurses’ knowledge on the prevention of the three adverse events was 0.19 points on a zero to ten scale (95% CI: ?0.03 to 0.42), in favour of the intervention group. There was a statistically significant effect on knowledge of pressure ulcers, with an improved mean mark of 0.45 points (95% CI: 0.10–0.81). For the other two topics there was no statistically significant effect. Nursing home nurses’ knowledge did neither improve (0 points, CI: ?0.35 to 0.35) overall, nor for the separate subjects.Conclusion: the educational intervention improved hospital nurses’ knowledge on the prevention of pressure ulcers only. More research on long term improvement of knowledge is neede