A Solution to the Graceful Exit Problem in Pre-Big Bang Cosmology

We examine the string cosmology equations with a dilaton potential in the context of the Pre-Big Bang Scenario with the desired scale factor duality, and give a generic algorithm for obtaining solutions with appropriate evolutionary properties. This enables us to find pre-big bang type solutions with suitable dilaton behaviour that are regular at $t=0$, thereby solving the graceful exit problem. However to avoid fine tuning of initial data, an `exotic' equation of state is needed that relates the fluid properties to the dilaton field. We discuss why such an equation of state should be required for reliable dilaton behaviour at late times.Comment: 16 pages LaTeX, 5 figures. To appear in Physical Review

Tuberculous meningitis in children: reducing the burden of death and disability

Tuberculous meningitis disproportionately affects young children. As the most devastating form of tuberculosis, it is associated with unacceptably high rates of mortality and morbidity even if treated. Challenging to diagnose and treat, tuberculous meningitis commonly causes long-term neurodisability in those who do survive. There remains an urgent need for strengthened surveillance, improved rapid diagnostics technology, optimised anti-tuberculosis drug therapy, investigation of new host-directed therapy, and further research on long-term functional and neurodevelopmental outcomes to allow targeted intervention. This review focuses on the neglected field of paediatric tuberculous meningitis and bridges current clinical gaps with research questions to improve outcomes from this crippling disease

Recent developments in Tuberculous meningitis pathogenesis and diagnostics [version 2; peer review: 1 approved]

The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a “one-size-fits-all” approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens

Brane Dynamics in the Randall-Sundrum model, Inflation and Graceful Exit

We study the averaged action of the Randall-Sundrum model with a time dependent metric ansatz. It can be reformulated in terms of a Brans-Dicke action with time dependent Newton's constant. We show that the physics of early universe, particularly inflation, is governed by the Brans-Dicke theory. The Brans-Dicke scalar, however, quickly settles to its equilibrium value and decouples from the post-inflationary cosmology. The deceleration parameter is negative to start with but changes sign before the Brans-Dicke scalar settles to its equilibrium value. Consequently, the brane metric smoothly exits inflation. We have also studied the slow-roll inflation in our model and investigated the spectra of the density perturbation generated by the radion field and find them consistent with the current observations.Comment: Revised version, Accepted in Class. Quant. Gravit

Bacille Calmette-Guerin (BCG) vaccine and the COVID-19 pandemic : responsible stewardship is needed

CITATION: Schaaf, H. S. et al. 2020. Bacille Calmette-Guerin (BCG) vaccine and the COVID-19 pandemic : responsible stewardship is needed. International Journal of Tuberculosis and Lung Disease, 4(7):732-734, doi:10.5588/ijtld.20.0267.The original publication is available at https://www.theunion.org/what-we-do/journals/ijtldWe believe that responsible stewardship of the bacille Calmette-Guérin (BCG) vaccine in the context of the COVID-19 epidemic is urgently needed. Live attenuated BCG is currently the only licensed vaccine to protect against tuberculosis (TB). Neonatal BCG vaccination has proven efficacy in protecting infants and young children against life-threatening disseminated forms of TB, including TB meningitis and miliary TB.Post-prin

Trading Justice for Peace? Reframing reconciliation in TRC processes in South Africa, Canada and Nordic countries

Conflict in its various manifestations continues to be a defining feature in many places throughout the world. In an attempt to address such conflict, various forms of a Truth and Reconciliation Commission (TRC) have been introduced to facilitate the transition from social conflict to a new dispensation. The introduction and subsequent proceedings of TRCs in South Africa, Canada and Norway are widely regarded as good examples of this approach. Against this background, a number of researchers from VID Specialized University and the University of the Western Cape had an exploratory meeting in Oslo in 2018 where the possibility for a joint research project under the broad theme of ‘discourses on reconciliation’ was first discussed. This led to two further research symposia in Cape Town and Tromsø in 2019. With the inclusion of specialists working on the Canadian Truth and Reconciliation process, these meetings demonstrated common ground and a shared understanding of the issues at stake. Moreover, it pointed to the differences between the South African, Canadian and Norwegian Commissions. In comparing the South African, Canadian and Norwegian experiences, researchers identified that these countries were, in fact, at different stages of their respective truth and reconciliation processes. This has prompted scholars to revisit and problematise these processes in relation to ongoing societal challenges. In all cases, it is quite apparent that reconciliation between individuals and groups remains a significant challenge

The avoiding late diagnosis of ovarian cancer (ALDO) project; A pilot national surveillance programme for women with pathogenic germline variants in BRCA1 and BRCA2

Background: Our study aimed to establish â € real-world' performance and cost-effectiveness of ovarian cancer (OC) surveillance in women with pathogenic germline BRCA1/2 variants who defer risk-reducing bilateral salpingo-oophorectomy (RRSO). Methods: Our study recruited 875 female BRCA1/2-heterozygotes at 13 UK centres and via an online media campaign, with 767 undergoing at least one 4-monthly surveillance test with the Risk of Ovarian Cancer Algorithm (ROCA) test. Surveillance performance was calculated with modelling of occult cancers detected at RRSO. The incremental cost-effectiveness ratio (ICER) was calculated using Markov population cohort simulation. Results: Our study identified 8 OCs during 1277 women screen years: 2 occult OCs at RRSO (both stage 1a), and 6 screen-detected; 3 of 6 (50%) were ≤stage 3a and 5 of 6 (83%) were completely surgically cytoreduced. Modelled sensitivity, specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) for OC were 87.5% (95% CI, 47.3 to 99.7), 99.9% (99.9-100), 75% (34.9-96.8) and 99.9% (99.9-100), respectively. The predicted number of quality-Adjusted life years (QALY) gained by surveillance was 0.179 with an ICER cost-saving of-£102,496/QALY. Conclusion: OC surveillance for women deferring RRSO in a â € real-world' setting is feasible and demonstrates similar performance to research trials; it down-stages OC, leading to a high complete cytoreduction rate and is cost-saving in the UK National Health Service (NHS) setting. While RRSO remains recommended management, ROCA-based surveillance may be considered for female BRCA-heterozygotes who are deferring such surgery