Knowledge Management in Information Technology Help Desk:Past, Present and Future

Information technology has changed the way organizations function. This resulted in the reliance of help desks to deal with information technology related areas such as hardware, software, and telecommunication. Besides, the adoption of business process reengineering and downsizing have led to the shrinkage of the size of help desk. The shorter information technology product life cycle has worsened the situation by increasing the already sizeable help desk’s user base. Consequently, the help desk has to cover more information technology products and resolute more technical enquiries with less staff. Thus, the outcome is clear that users have to wait comparably longer before help desk staff is available to offer assistance. This paper describes the contribution of knowledge management in retaining knowledge and solving “knowledge leaking” problem. The research presents the development of user selfhelp knowledge management system to re-distribute incoming enquiries so that simple and routine technical enquiries can be resolved without help desk intervention

Exploring the diversity of double-detonation explosions for Type Ia supernovae: effects of the post-explosion helium shell composition

The detonation of a helium shell on top of a carbon-oxygen white dwarf has been argued as a potential explosion mechanism for Type Ia supernovae (SNe Ia). The ash produced during helium shell burning can lead to light curves and spectra that are inconsistent with normal SNe Ia, but may be viable for some objects showing a light-curve bump within the days following explosion. We present a series of radiative transfer models designed to mimic predictions from double-detonation explosion models. We consider a range of core and shell masses, and systematically explore multiple post-explosion compositions for the helium shell. We find that a variety of luminosities and time-scales for early light-curve bumps result from those models with shells containing Ni-56,Fe- 52, or Cr-48. Comparing our models to SNe Ia with light-curve bumps, we find that these models can reproduce the shapes of almost all of the bumps observed, but only those objects with red colours around maximum light (B - V greater than or similar to 1) are well matched throughout their evolution. Consistent with previous works, we also show that those models in which the shell does not contain iron-group elements provide good agreement with normal SNe Ia of different luminosities from shortly after explosion up to maximum light. While our models do not amount to positive evidence in favour of the double-detonation scenario, we show that provided the helium shell ash does not contain iron-group elements, it may be viable for a wide range of normal SNe Ia

Detecting the signatures of helium in type Iax supernovae

Recent studies have argued that the progenitor system of type Iax supernovae must consist of a carbon-oxygen white dwarf accreting from a helium star companion. Based on existing explosion models invoking the pure deflagration of carbon-oxygen white dwarfs, we investigate the likelihood of producing spectral features due to helium in type Iax supernovae. From this scenario, we select those explosion models producing ejecta and Ni-56 masses that are broadly consistent with those estimated for type Iax supernovae (0.014-0.478M(circle dot) and similar to 0.003-0.183 M-circle dot, respectively). To this end, we present a series of models of varying luminosities (-18.4 less than or similar to M-V less than or similar to -14.5 mag) with helium abundances accounting for up to similar to 36% of the ejecta mass, and covering a range of epochs beginning a few days before B-band maximum to approximately two weeks after maximum. We find that the best opportunity for detecting He (I) features is at near-infrared wavelengths, and in the post-maximum spectra of the fainter members of this class. We show that the optical spectrum of SN 2007J is potentially consistent with a large helium content (a few 10(-2) M-circle dot), but argue that current models of accretion and material stripping from a companion struggle to produce compatible scenarios. We also investigate the presence of helium in all objects with near-infrared spectra. We show that SNe 2005hk, 2012Z, and 2015H contain either no helium or their helium abundances are constrained to much lower values (less than or similar to 10(-3) M-circle dot). For the faint type Iax supernova, SN 2010ae, we tentatively identify a small helium abundance from its near-infrared spectrum. Our results demonstrate the differences in helium content among type Iax supernovae, perhaps pointing to different progenitor channels. Either SN 2007J is an outlier in terms of its progenitor system, or it is not a true member of the type Iax supernova class

Spatial heterogeneity and peptide availability determine CTL killing efficiency in vivo

The rate at which a cytotoxic T lymphocyte (CTL) can survey for infected cells is a key ingredient of models of vertebrate immune responses to intracellular pathogens. Estimates have been obtained using in vivo cytotoxicity assays in which peptide-pulsed splenocytes are killed by CTL in the spleens of immunised mice. However the spleen is a heterogeneous environment and splenocytes comprise multiple cell types. Are some cell types intrinsically more susceptible to lysis than others? Quantitatively, what impacts are made by the spatial distribution of targets and effectors, and the level of peptide-MHC on the target cell surface? To address these questions we revisited the splenocyte killing assay, using CTL specific for an epitope of influenza virus. We found that at the cell population level T cell targets were killed more rapidly than B cells. Using modeling, quantitative imaging and in vitro killing assays we conclude that this difference in vivo likely reflects different migratory patterns of targets within the spleen and a heterogeneous distribution of CTL, with no detectable difference in the intrinsic susceptibilities of the two populations to lysis. Modeling of the stages involved in the detection and killing of peptide-pulsed targets in vitro revealed that peptide dose influenced the ability of CTL to form conjugates with targets but had no detectable effect on the probability that conjugation resulted in lysis, and that T cell targets took longer to lyse than B cells. We also infer that incomplete killing in vivo of cells pulsed with low doses of peptide may be due to a combination of heterogeneity in peptide uptake and the dissociation, but not internalisation, of peptide-MHC complexes. Our analyses demonstrate how population-averaged parameters in models of immune responses can be dissected to account for both spatial and cellular heterogeneity

First analysis of anisotropic flow with Lee--Yang zeroes

We report on the first analysis of directed and elliptic flow with the new method of Lee--Yang zeroes. Experimental data are presented for Ru+Ru reactions at 1.69 AGeV measured with the FOPI detector at SIS/GSI. The results obtained with several methods, based on the event-plane reconstruction, on Lee--Yang zeroes, and on multi-particle cumulants (up to 5th order) applied for the first time at SIS energies, are compared. They show conclusive evidence that azimuthal correlations between nucleons and composite particles at this energy are largely dominated by anisotropic flow.Comment: 5 pages, 3 figures, submitted to Phys. Rev. C Rapid Co

Simultaneous Activation of Complement and Coagulation by MBL-Associated Serine Protease 2

The complement system is an important immune mechanism mediating both recognition and elimination of foreign bodies. The lectin pathway is one pathway of three by which the complement system is activated. The characteristic protease of this pathway is Mannan-binding lectin (MBL)-associated serine protease 2 (MASP2), which cleaves complement proteins C2 and C4. We present a novel and alternative role of MASP2 in the innate immune system. We have shown that MASP2 is capable of promoting fibrinogen turnover by cleavage of prothrombin, generating thrombin. By using a truncated active form of MASP2 as well as full-length MASP2 in complex with MBL, we have shown that the thrombin generated is active and can cleave both factor XIII and fibrinogen, forming cross-linked fibrin. To explore the biological significance of these findings we showed that fibrin was covalently bound on a bacterial surface to which MBL/MASP2 complexes were bound. These findings suggest that, as has been proposed for invertebrates, limited clotting may contribute to the innate immune response

Exercise training as a novel primary treatment for localised prostate cancer: a multi-site randomised controlled phase II study

Alternative management strategies for localised prostate cancer are required to reduce morbidity and overtreatment. The aim of this study was to evaluate the feasibility, safety and acceptability of exercise training (ET) with behavioural support as a primary therapy for low/intermediate risk localised prostate cancer. Men with low/intermediate-risk prostate cancer were randomised to 12 months of ET or usual care with physical activity advice (UCwA) in a multi-site open label RCT. Feasibility included acceptability, recruitment, retention, adherence, adverse events and disease progression. Secondary outcomes included quality of life and cardiovascular health indices. Of the 50 men randomised to ET (n=25) or UCwA (n=25), 92% (n=46) completed 12 month assessments. Three men progressed to invasive therapy (two in UCwA). In the ET group, men completed mean: 140 mins per week for 12 months (95% CI 129,152mins) (94% of target dose) at 75% Hrmax. Men in the ET group demonstrated improved body mass (mean reduction: 2.0 kg; 95% CI -2.9,-1.1), reduced systolic (mean: 13 mmHg; 95% CI 7,19) and diastolic blood pressure (mean:8 mmHg; 95% CI 5,12) and improved quality of life (EQ5D mean:13 points; 95% CI 7,18). There were no serious adverse events. ET in men with low/intermediate risk prostate cancer is feasible and acceptable with a low progression rate to radical treatment. Early signals on clinically relevant markers were found which warrant further investigation

Growing evidence that SNe Iax are not a one-parameter family The case of PS1-12bwh

In this study, we present observations of a type Iax supernova, PS1-12bwh, discovered during the Pan-STARRS1 3 pi-survey. Our analysis was driven by previously unseen pre-maximum, spectroscopic heterogeneity. While the light curve and post-maximum spectra of PS1-12bwh are virtually identical to those of the well-studied type Iax supernova, SN 2005hk, the -2 day spectrum of PS1-12bwh does not resemble SN 2005hk at a comparable epoch; instead, we found it to match a spectrum of SN 2005hk taken over a week earlier (12 day). We are able to rule out the cause as being incorrect phasing, and argue that it is not consistent with orientation effects predicted by existing explosion simulations. To investigate the potential source of this difference, we performed radiative transfer modelling of both supernovae. We found that the pre-maximum spectrum of PS1-12bwh is well matched by a synthetic spectrum generated from a model with a lower density in the high velocity (greater than or similar to 6000 km s(-1)) ejecta than SN 2005hk. The observed differences between SN 2005hk and PS1-12bwh may therefore be attributed primarily to differences in the high velocity ejecta alone, while comparable densities for the lower velocity ejecta would explain the nearly identical post-maximum spectra. These two supernovae further highlight the diversity within the SNe Iax class, as well as the challenges in spectroscopically identifying and phasing these objects, especially at early epochs