A framework for P2P application development

Although Peer-to-Peer (P2P) computing has become increasingly popular over recent years, there still exist only a very small number of application domains that have exploited it on a large scale. This can be attributed to a number of reasons including the rapid evolution of P2P technologies, coupled with their often-complex nature. This paper describes an implemented abstraction framework that seeks to aid developers in building P2P applications. A selection of example P2P applications that have been developed using this framework are also presented

Radical political unionism reassessed

Defections from European social-democratic parties and a resurgence of union militancy have prompted some to diagnose a new left-wing trade unionism across Europe. This comment on the article by Connolly and Darlington scrutinizes trends in France and Germany but primarily analyses recent developments in Britain. While there are some instances of disaffiliation from the Labour Party, support for electoral alternatives, growth in political militancy and emphasis on new forms of internationalism, these have been limited. There is insufficient evidence to suggest that we are witnessing the making of a new radical collectivism

Morphology and biomechanics of the nests of the Common Blackbird Turdus merula

Capsule Common blackbirds select different materials, with varying biomechanical properties, to construct different parts of their nest. Aims This study tested the hypothesis that outer components of a nest have a more structural role and so are stronger than materials used to line the cup. Methods Blackbird nests were measured prior to being dismantled to isolate structural components which were tested for mechanical strength and rigidity. Results Outer nest wall materials were significantly thicker, stronger and more rigid than materials in the inner structural wall or the cup lining. In the vertical plane materials used in the structural wall did not differ. By contrast, lining materials from the bottom of the nest cup were significantly thicker, stronger and more rigid than materials from the top of the cup. Conclusion Blackbirds use different materials in nest construction roles suited to their properties and so may be able to recognise the structural properties of these materials. Materials on the outside of the nest may have a key structural role during construction

Empirical predictive models of daily relativistic electron flux at geostationary orbit: Multiple regression analysis

The daily maximum relativistic electron flux at geostationary orbit can be predicted well with a set of daily averaged predictor variables including previous day's flux, seed electron flux, solar wind velocity and number density, AE index, IMF Bz, Dst, and ULF and VLF wave power. As predictor variables are intercorrelated, we used multiple regression analyses to determine which are the most predictive of flux when other variables are controlled. Empirical models produced from regressions of flux on measured predictors from 1 day previous were reasonably effective at predicting novel observations. Adding previous flux to the parameter set improves the prediction of the peak of the increases but delays its anticipation of an event. Previous day's solar wind number density and velocity, AE index, and ULF wave activity are the most significant explanatory variables; however, the AE index, measuring substorm processes, shows a negative correlation with flux when other parameters are controlled. This may be due to the triggering of electromagnetic ion cyclotron waves by substorms that cause electron precipitation. VLF waves show lower, but significant, influence. The combined effect of ULF and VLF waves shows a synergistic interaction, where each increases the influence of the other on flux enhancement. Correlations between observations and predictions for this 1 day lag model ranged from 0.71 to 0.89 (average: 0.78). A path analysis of correlations between predictors suggests that solar wind and IMF parameters affect flux through intermediate processes such as ring current (Dst), AE, and wave activity

Trade unions and the challenge of fostering solidarities in an era of financialisation

This articles re-examines evidence that trade unions in the UK have struggled to renew themselves despite considerable investment of time and effort. It argues that financialisation in the realms of capital accumulation, organisational decision making and everyday life has introduced new barriers to building the solidarities within and between groups of workers that would be necessary to develop a stronger response to the catastrophic effects on labour of financialisation in general, and the financial crisis specifically. The crisis highlighted the weaknesses of trade unions as institutions of economic and industrial democracy, but has also given some opportunities to establish narratives of solidarity in spaces and platforms created within a financialised context

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

High-temperature performance of ferritic steels in fireside corrosion regimes: temperature and deposits

The paper reports high temperature resistance of ferritic steels in fireside corrosion regime in terms of temperature and deposits aggressiveness. Four candidate power plant steels: 15Mo3, T22, T23 and T91 were exposed under simulated air-fired combustion environment for 1000 h. The tests were conducted at 600, 650 and 700 °C according to deposit-recoat test method. Post-exposed samples were examined via dimensional metrology (the main route to quantify metal loss), and mass change data were recorded to perform the study of kinetic behavior at elevated temperatures. Microstructural investigations using ESEM-EDX were performed in order to investigate corrosion degradation and thickness of the scales. The ranking of the steels from most to the least damage was 15Mo3 > T22 > T23 > T91 in all three temperatures. The highest rate of corrosion in all temperatures occurred under the screening deposit

Anti-GnRH antibodies can induce castrate levels of testosterone in patients with advanced prostate cancer

D17DT consists of the GnRH decapeptide linked to diphtheria toxoid. The aim of this pilot study was to assess the tolerance of D17DT and the production of anti-GnRH antibodies from two doses, 30 and 100 μg, in patients with locally advanced prostate cancer. Twelve patients with histologically proven prostate cancer in whom hormonal therapy was indicated were recruited. Patients received either 30 or 100 μg given intramuscularly on three separate occasions over six weeks. Patients were followed up and blood was taken for estimation of serum testosterone, PSA and anti-GnRH antibody titre. Overall the drug was well tolerated. In 5 patients a significant reduction in serum testosterone and PSA was seen. Castrate levels of testosterone were achieved in 4 and maintained for up to 9 months. Patients with the highest antibody titre had the best response in terms of testosterone suppression. This study shows that it is possible to immunize a patient with prostate cancer against GnRH to induce castrate levels of testosterone. This state appears to be reversible. This novel form of immunotherapy may have advantages over conventional forms of hormonal therapy and further studies are warranted in order to try and increase the proportion of responders. © 2000 Cancer Research Campaig

Family Resemblances? Ligand Binding and Activation of Family A and B G-Protein-Coupled Receptors Ligand binding and activation of the CGRP receptor

Abstract The receptor for CGRP (calcitonin gene-related peptide) is a heterodimer between a GPCR (G-proteincoupled receptor), CLR (calcitonin receptor-like receptor) and an accessory protein, RAMP1 (receptor activitymodifying protein 1). Models have been produced of RAMP1 and CLR. It is likely that the C-terminus of CGRP interacts with the extracellular N-termini of CLR and RAMP1; the extreme N-terminus of CLR is particularly important and may interact directly with CGRP and also with RAMP1. The N-terminus of CGRP interacts with the TM (transmembrane) portion of the receptor; the second ECL (extracellular loop) is especially important. Receptor activation is likely to involve the relative movements of TMs 3 and 6 to create a G-protein-binding pocket, as in Family A GPCRs. Pro 321 in TM6 appears to act as a pivot. At the base of TMs 2 and 3, Arg 151 , His 155 and Glu 211 may form a loose equivalent of the Family A DRY (Asp-Arg-Tyr) motif. Although the details of this proposed activation mechanism clearly do not apply to all Family B GPCRs, the broad outlines may be conserved