Introducing risk management into the grid

Service Level Agreements (SLAs) are explicit statements about all expectations and obligations in the business partnership between customers and providers. They have been introduced in Grid computing to overcome the best effort approach, making the Grid more interesting for commercial applications. However, decisions on negotiation and system management still rely on static approaches, not reflecting the risk linked with decisions. The EC-funded project "AssessGrid" aims at introducing risk assessment and management as a novel decision paradigm into Grid computing. This paper gives a general motivation for risk management and presents the envisaged architecture of a "risk-aware" Grid middleware and Grid fabric, highlighting its functionality by means of three showcase scenarios

A bilateral shear layer between two parallel Couette flows

We consider a shear layer of a kind not previously studied to our knowledge. Contrary to the classical free shear layer, the width of the shear zone does not vary in the streamwise direction but rather exhibits a lateral variation. Based on some simplifying assumptions, an analytic solution has been derived for the new shear layer. These assumptions have been justified by a comparison with numerical solutions of the full Navier-Stokes equations, which accord with the analytical solution to better than 1% in the entire domain. An explicit formula is found for the width of the shear zone as a function of wall-normal coordinate. This width is independent of wall velocities in the laminar regime. Preliminary results for a co-current laminar-turbulent shear layer in the same geometry are also presented. Shear-layer instabilities were then developed and resulted in an unsteady mixing zone at the interface between the two co-current streams.Comment: 6 pages, 7 figures. Accepted for publication in Phys. Rev.

Dynamical effects induced by long range activation in a nonequilibrium reaction-diffusion system

We both show experimentally and numerically that the time scales separation introduced by long range activation can induce oscillations and excitability in nonequilibrium reaction-diffusion systems that would otherwise only exhibit bistability. Namely, we show that the Chlorite-Tetrathionate reaction, where autocatalytic species diffuses faster than the substrates, the spatial bistability domain in the nonequilibrium phase diagram is extended with oscillatory and excitability domains. A simple model and a more realistic model qualitatively account for the observed behavior. The latter model provides quantitative agreement with the experiments.Comment: 19 pages + 9 figure

Learning from Lockdown: Listening to students' voices about the challenges and benefits in the post-COVID-19 digital practices

The sudden move to remote teaching and learning in Spring 2020 brought together staff and students in order to learn from each other how to best address the challenges of the new ways of teaching and learning. In this synchronous presentation the seven authors will take turns: *to introduce the two institutionally-supported studies conducted last year, one surveying the UCL undergraduates, and the other one surveying the postgraduate taught students in the CPA department of UCL IoE; *to share the framework that guided the analysis of students’ views of their experiences and priorities surrounding online learning, gathered via online surveys and focussed group discussions; *to propose alternative conceptions for what could be a meaningful and rich online educative experience; *to discuss our findings and their implications for theory, research, policy and practice in a post-pandemic context; and last and most important, *to describe how staff and students collaborated on carrying out these projects, and later worked together to write an academic paper about to the two projects

Engagement discourses, relationality and the student voice: connectedness, questioning and inclusion in post-Covid digital practices

The Covid-19 crisis has led to a rapid pivot to online teaching and student engagement across higher education internationally, due to public health ‘lockdown’ measures. In March 2020 in the UK this move was sudden, and universities were forced to move their provision to digital formats with little preparatory time, and in many cases, inadequate training and experience. In the subsequent period, higher education institutions have prioritised the enhancement of digital education, with a range of strategic initiatives and training programmes for teaching staff. This paper, written by a staff-student partnership of authors, reports on two institutionally-supported studies conducted at a large, research-focused university in England, in which student views were sought on their experiences and priorities surrounding online engagement during the Covid-19 crisis. In our discussion of the findings, we argue that the student accounts challenge some of the mainstream assumptions about constructs such as student ‘inclusivity’, academic ‘community’ online, and teaching which encourages ‘questioning’, requiring us to think more deeply about what constitutes a meaningful and rich online educative experience. In the spirit of ‘lessons learned’ from the Covid-19 pandemic, the paper proposes alternative conceptions of these values, emphasising relationality, communities, difference, and the importance of an ethos of care. We conclude with a discussion of findings, implications for theory, research, policy and practice in a post-pandemic context, proposing that an ethos of care be recognised as central to the development of digital education and the practices and ethics of student engagement

Awareness and uptake of layered HIV prevention programming for young women: analysis of population-based surveys in three DREAMS settings in Kenya and South Africa

Background The DREAMS Partnership is an ambitious effort to deliver combinations of biomedical, behavioural and structural interventions to reduce HIV incidence among adolescent girls and young women (AGYW). To inform multi-sectoral programming at scale, across diverse settings in Kenya and South Africa, we identified who the programme is reaching, with which interventions and in what combinations. Methods Randomly-selected cohorts of 606 AGYW aged 10–14 years and 1081 aged 15–22 years in Nairobi and 2184 AGYW aged 13–22 years in uMkhanyakude, KwaZulu-Natal, were enrolled in 2017, after ~ 1 year of DREAMS implementation. In Gem, western Kenya, population-wide cross-sectional survey data were collected during roll-out in 2016 (n = 1365 AGYW 15–22 years). We summarised awareness and invitation to participate in DREAMS, uptake of interventions categorised by the DREAMS core package, and uptake of a subset of ‘primary’ interventions. We stratified by age-group and setting, and compared across AGYW characteristics. Results Awareness of DREAMS was higher among younger women (Nairobi: 89%v78%, aged 15-17v18–22 years; uMkhanyakude: 56%v31%, aged 13-17v18–22; and Gem: 28%v25%, aged 15-17v18–22, respectively). HIV testing was the most accessed intervention in Nairobi and Gem (77% and 85%, respectively), and school-based HIV prevention in uMkhanyakude (60%). Among those invited, participation in social asset building was > 50%; > 60% accessed ≥2 core package categories, but few accessed all primary interventions intended for their age-group. Parenting programmes and community mobilisation, including those intended for male partners, were accessed infrequently. In Nairobi and uMkhanyakude, AGYW were more likely to be invited to participate and accessed more categories if they were: aged < 18 years, in school and experienced socio-economic vulnerabilities. Those who had had sex, or a pregnancy, were less likely to be invited to participate but accessed more categories. Conclusions In representative population-based samples, awareness and uptake of DREAMS were high after 1 year of implementation. Evidence of ‘layering’ (receiving multiple interventions from the DREAMS core package), particularly among more socio-economically vulnerable AGYW, indicate that intervention packages can be implemented at scale, for intended recipients, in real-world contexts. Challenges remain for higher coverage and greater ‘layering’, including among older, out-of-school AGYW, and community-based programmes for families and men

Kinase and channel activity of TRPM6 are co-ordinated by a dimerization motif and pocket interaction

Contains fulltext : 138516.pdf (publisher's version ) (Open Access)Mutations in the gene that encodes the atypical channel-kinase TRPM6 (transient receptor potential melastatin 6) cause HSH (hypomagnesaemia with secondary hypocalcaemia), a disorder characterized by defective intestinal Mg2+ transport and impaired renal Mg2+ reabsorption. TRPM6, together with its homologue TRPM7, are unique proteins as they combine an ion channel domain with a C-terminally fused protein kinase domain. How TRPM6 channel and kinase activity are linked is unknown. Previous structural analysis revealed that TRPM7 possesses a non-catalytic dimerization motif preceding the kinase domain. This interacts with a dimerization pocket lying within the kinase domain. In the present study, we provide evidence that the dimerization motif in TRPM6 plays a critical role in regulating kinase activity as well as ion channel activity. We identify mutations within the TRPM6 dimerization motif (Leu1718 and Leu1721) or dimerization pocket (L1743A, Q1832K, A1836N, L1840A and L1919Q) that abolish dimerization and establish that these mutations inhibit protein kinase activity. We also demonstrate that kinase activity of a dimerization motif mutant can be restored by addition of a peptide encompassing the dimerization motif. Moreover, we observe that mutations that disrupt the dimerization motif and dimerization pocket interaction greatly diminish TRPM6 ion channel activity, in a manner that is independent of kinase activity. Finally, we analyse the impact on kinase activity of ten disease-causing missense mutations that lie outwith the protein kinase domain of TRPM6. This revealed that one mutation lying nearby the dimerization motif (S1754N), found previously to inhibit channel activity, abolished kinase activity. These results provide the first evidence that there is structural co-ordination between channel and kinase activity, which is mediated by the dimerization motif and pocket interaction. We discuss that modulation of this interaction could comprise a major regulatory mechanism by which TRPM6 function is controlled

Evaluating the impact of DREAMS on HIV incidence among adolescent girls and young women: A population-based cohort study in Kenya and South Africa

Background: Through a multisectoral approach, the DREAMS Partnership aimed to reduce HIV incidence among adolescent girls and young women (AGYW) by 40% over 2 years in high-burden districts across sub-Saharan Africa. DREAMS promotes a combination package of evidence-based interventions to reduce individual, family, partner, and community-based drivers of young women’s heightened HIV risk. We evaluated the impact of DREAMS on HIV incidence among AGYW and young men in 2 settings. // Methods and findings: We directly estimated HIV incidence rates among open population-based cohorts participating in demographic and HIV serological surveys from 2006 to 2018 annually in uMkhanyakude (KwaZulu-Natal, South Africa) and over 6 rounds from 2010 to 2019 in Gem (Siaya, Kenya). We compared HIV incidence among AGYW aged 15 to 24 years before DREAMS and up to 3 years after DREAMS implementation began in 2016. We investigated the timing of any change in HIV incidence and whether the rate of any change accelerated during DREAMS implementation. Comparable analyses were also conducted for young men (20 to 29/34 years). In uMkhanyakude, between 5,000 and 6,000 AGYW were eligible for the serological survey each year, an average of 85% were contacted, and consent rates varied from 37% to 67%. During 26,395 person-years (py), HIV incidence was lower during DREAMS implementation (2016 to 2018) than in the previous 5-year period among 15- to 19-year-old females (4.5 new infections per 100 py as compared with 2.8; age-adjusted rate ratio (aRR) = 0.62, 95% confidence interval [CI] 0.48 to 0.82), and lower among 20- to 24-year-olds (7.1/100 py as compared with 5.8; aRR = 0.82, 95% CI 0.65 to 1.04). Declines preceded DREAMS introduction, beginning from 2012 to 2013 among the younger and 2014 for the older women, with no evidence of more rapid decline during DREAMS implementation. In Gem, between 8,515 and 11,428 AGYW were eligible each survey round, an average of 34% were contacted and offered an HIV test, and consent rates ranged from 84% to 99%. During 10,382 py, declines in HIV incidence among 15- to 19-year-olds began before DREAMS and did not change after DREAMS introduction. Among 20- to 24-year-olds in Gem, HIV incidence estimates were lower during DREAMS implementation (0.64/100 py) compared with the pre-DREAMS period (0.94/100 py), with no statistical evidence of a decline (aRR = 0.69, 95% CI 0.53 to 2.18). Among young men, declines in HIV incidence were greater than those observed among AGYW and also began prior to DREAMS investments. Study limitations include low study power in Kenya and the introduction of other interventions such as universal treatment for HIV during the study period. // Conclusions: Substantial declines in HIV incidence among AGYW were observed, but most began before DREAMS introduction and did not accelerate in the first 3 years of DREAMS implementation. Like the declines observed among young men, they are likely driven by earlier and ongoing investments in HIV testing and treatment. Longer-term implementation and evaluation are needed to assess the impact of such a complex HIV prevention intervention and to help accelerate reductions in HIV incidence among young women

A Phylogenetic Analysis of HIV-1 Sequences in Kiev: Findings among Key Populations

BACKGROUND: The HIV epidemic in Ukraine has been driven by a rapid rise among people who inject drugs, but recent studies have shown an increase through sexual transmission. METHODS: Protease and RT sequences from 876 new HIV diagnoses (April 2013 - March 2015) in Kiev were linked to demographic data. We constructed phylogenetic trees for 794 subtype A1 and 64 subtype B sequences and identified factors associated with transmission clustering. Clusters were defined as ≥ 2 sequences, ≥ 80% local branch support and maximum genetic distance of all sequence pairs in the cluster ≤ 2.5%. Recent infection was determined through the LAg avidity EIA assay. Sequences were analysed for transmitted drug resistance (TDR) mutations. RESULTS: 30% of subtype A1 and 66% of subtype B sequences clustered. Large clusters (maximum 11 sequences) contained mixed risk groups. In univariate analysis, clustering was significantly associated with subtype B compared to A1 (OR 4.38 [95% CI 2.56-7.50]), risk group (OR 5.65 [3.27-9.75]) for men who have sex with men compared to heterosexual males, recent, compared to long-standing, infection (OR 2.72 [1.64-4.52]), reported sex work contact (OR 1.93 [1.07-3.47]) and younger age groups compared to age ≥36 (OR 1.83 [1.10-3.05] for age ≤25). Females were associated with lower odds of clustering than heterosexual males (OR 0.49 [0.31-0.77]). In multivariate analysis, risk group, subtype and age group were independently associated with clustering (p<0.001, p=0.007 and p=0.033). 18 sequences (2.1%) indicated evidence of TDR. CONCLUSIONS: Our findings suggest high levels of transmission and bridging between risk groups

Transverse Λ0\Lambda^0 polarization in inclusive quasi-real photoproduction at the current fragmentation

It is shown that the recent HERMES data on the transverse $\Lambda^0$ polarization in the inclusive quasi-real photoproduction at $x_F>0$ can be accommodated by the strange quark scattering model. Relations with the quark recombination approach are discussed.Comment: 5 pages, 3 figures, accepted by Eur. Phys. J.