A note on the Weiss conjecture

Let G be a finite group acting vertex-transitively on a graph. We show that bounding the order of a vertex stabilizer is equivalent to bounding the second singular value of a particular bipartite graph. This yields an alternative formulation of the Weiss Conjecture

CO(1-0) in z ≳ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs

We present ^(12)CO(J = 1 → 0) observations of the high-redshift quasi-stellar objects (QSOs) BR 1202-0725 (z = 4.69), PSS J2322+1944 (z = 4.12), and APM 08279+5255 (z = 3.91) using the NRAO Green Bank Telescope (GBT) and the MPIfR Effelsberg 100 m telescope. We detect, for the first time, the CO ground-level transition in BR 1202-0725. For PSS J2322+1944 and APM 08279+5255, our observations result in line fluxes that are consistent with previous NRAO Very Large Array (VLA) observations, but they reveal the full line profiles. We report a typical lensing-corrected velocity-integrated intrinsic ^(12)CO(J = 1 → 0) line luminosity of L'_(CO) = 5 × 10^(10) K km s^(-1) pc^2 and a typical total H_2 mass of M(H_2) = 4 × 10^(10) M_☉ for the sources in our sample. The CO/FIR luminosity ratios of these high-z sources follow the same trend as seen for low-z galaxies, leading to a combined solution of log L_(FIR) = (1.39 ± 0.05) log L_(CO) - 1.76. It has previously been suggested that the molecular gas reservoirs in some quasar host galaxies may exhibit luminous, extended ^(12)CO(J = 1 → 0) components that are not observed in the higher J CO transitions. Using the line profiles and the total intensities of our observations and large velocity gradient (LVG) models based on previous results for higher J CO transitions, we derive that emission from all CO transitions is described well by a single gas component in which all molecular gas is concentrated in a compact nuclear region. Thus, our observations and models show no indication of a luminous extended, low surface brightness molecular gas component in any of the high-redshift QSOs in our sample. If such extended components exist, their contribution to the overall luminosity is limited to at most 30%

Multidisciplinary innovation Armenia: explorations in design-led multidisciplinary enterprise education

This paper addresses the question to what extent can rapid design-led interventions support enterprise education? The work is based on a three-year engagement with students and recent graduates in Armenia. It was inspired by a course of innovation-readiness workshops called Get Ready to Innovate used to support established small and medium-sized enterprises operating in North East England. The paper provides a critical assessment of the adaptation of the GRTI model for the Armenian situation and its strengths and limitations for addressing the requirements of innovation readiness (the willingness, creative mindset and plans to make a positive change) amongst budding Armenian entrepreneurs. Mixed-methods are used, combining inductive thematic analysis of participant surveys, co-reflective workshops and semi-structured interviews. Findings suggest that there are a number of benefits associated with adopting a design-led approach, including enhancing creative confidence and multidisciplinary team working. In comparison with other forms of enterprise education, participants and facilitators identified a greater emphasis on front-end exploration and stakeholder focus. It is also clear that there were shortcomings in the approach associated with a mismatch in expectations between the facilitators and participants. The authors identify the challenges associated with this mismatch and some steps they took to overcome these. Finally, they identify scope for future research that considers implications for educational and enterprise-creation policy as well as discrete programme development

Mapping the zoonotic niche of Marburg virus disease in Africa.

BACKGROUND: Marburg virus disease (MVD) describes a viral haemorrhagic fever responsible for a number of outbreaks across eastern and southern Africa. It is a zoonotic disease, with the Egyptian rousette (Rousettus aegyptiacus) identified as a reservoir host. Infection is suspected to result from contact between this reservoir and human populations, with occasional secondary human-to-human transmission. METHODS: Index cases of previous human outbreaks were identified and reports of infection in animals recorded. These data were modelled within a species distribution modelling framework in order to generate a probabilistic surface of zoonotic transmission potential of MVD across sub-Saharan Africa. RESULTS: Areas suitable for zoonotic transmission of MVD are predicted in 27 countries inhabited by 105 million people. Regions are suggested for exploratory surveys to better characterise the geographical distribution of the disease, as well as for directing efforts to communicate the risk of practices enhancing zoonotic contact. CONCLUSIONS: These maps can inform future contingency and preparedness strategies for MVD control, especially where secondary transmission is a risk. Coupling this risk map with patient travel histories could be used to guide the differential diagnosis of highly transmissible pathogens, enabling more rapid response to outbreaks of haemorrhagic fever

Differential expression of the nuclear-encoded mitochondrial transcriptome in pediatric septic shock.

INTRODUCTION: Increasing evidence supports a role for mitochondrial dysfunction in organ injury and immune dysregulation in sepsis. Although differential expression of mitochondrial genes in blood cells has been reported for several diseases in which bioenergetic failure is a postulated mechanism, there are no data about the blood cell mitochondrial transcriptome in pediatric sepsis. METHODS: We conducted a focused analysis using a multicenter genome-wide expression database of 180 children ≤ 10 years of age with septic shock and 53 healthy controls. Using total RNA isolated from whole blood within 24 hours of PICU admission for septic shock, we evaluated 296 nuclear-encoded mitochondrial genes using a false discovery rate of 1%. A series of bioinformatic approaches were applied to compare differentially expressed genes across previously validated gene expression-based subclasses (groups A, B, and C) of pediatric septic shock. RESULTS: In total, 118 genes were differentially regulated in subjects with septic shock compared to healthy controls, including 48 genes that were upregulated and 70 that were downregulated. The top scoring canonical pathway was oxidative phosphorylation, with general downregulation of the 51 genes corresponding to the electron transport system (ETS). The top two gene networks were composed primarily of mitochondrial ribosomal proteins highly connected to ETS complex I, and genes encoding for ETS complexes I, II, and IV that were highly connected to the peroxisome proliferator activated receptor (PPAR) family. There were 162 mitochondrial genes differentially regulated between groups A, B, and C. Group A, which had the highest maximum number of organ failures and mortality, exhibited a greater downregulation of mitochondrial genes compared to groups B and C. CONCLUSIONS: Based on a focused analysis of a pediatric septic shock transcriptomic database, nuclear-encoded mitochondrial genes were differentially regulated early in pediatric septic shock compared to healthy controls, as well as across genotypic and phenotypic distinct pediatric septic shock subclasses. The nuclear genome may be an important mechanism contributing to alterations in mitochondrial bioenergetic function and outcomes in pediatric sepsis

Doctoral Recital

List of performers and performances

Innovation Constellations as a systems approach to social design infrastructuring

There are constant calls for innovation related to complex social challenges. This includes calls to innovate within government and public organisational structures but expands to include unsustainable relationships and behaviours in public life. Design is often positioned as a capability that can offer new approaches and develop novel interventions with the design project as a key mechanism. Through a case study focused on an Innovation Constellation a discussion is developed about an emerging sociomaterial design infrastrucutring system. The case study presents a complex system of designing that highlights political infrastruturing as significant in supporting a diverse group to bridge the gap between social justice rhetoric and practical action to intervene and influence existing social circumstances

Direct comparison of nick-joining activity of the nucleic acid ligases from bacteriophage T4

The genome of bacteriophage T4 encodes three polynucleotide ligases, which seal the backbone of nucleic acids during infection of host bacteria. The T4Dnl (T4 DNA ligase) and two RNA ligases [T4Rnl1 (T4 RNA ligase 1) and T4Rnl2] join a diverse array of substrates, including nicks that are present in double-stranded nucleic acids, albeit with different efficiencies. To unravel the biochemical and functional relationship between these proteins, a systematic analysis of their substrate specificity was performed using recombinant proteins. The ability of each protein to ligate 20 bp double-stranded oligonucleotides containing a single-strand break was determined. Between 4 and 37 °C, all proteins ligated substrates containing various combinations of DNA and RNA. The RNA ligases ligated a more diverse set of substrates than T4Dnl and, generally, T4Rnl1 had 50-1000-fold lower activity than T4Rnl2. In assays using identical conditions, optimal ligation of all substrates was at pH 8 for T4Dnl and T4Rnl1 and pH 7 for T4Rnl2, demonstrating that the protein dictates the pH optimum for ligation. All proteins ligated a substrate containing DNA as the unbroken strand, with the nucleotides at the nick of the broken strand being RNA at the 3'-hydroxy group and DNA at the 5'-phosphate. Since this RNA-DNA hybrid was joined at a similar maximal rate by T4Dnl and T4Rnl2 at 37 °C, we consider the possibility that this could be an unexpected physiological substrate used during some pathways of 'DNA repair'

Three degrees of influence in virtual workshops: towards an understanding of co-creative facilitation practice in technologically mediated settings

Virtual workshops look here to stay, however much of the recent discourse fo-cuses on methods, tools, techniques and routines in abstraction from practice and practitioner. Collaborations in virtual space are necessarily changed and shaped by their technologically mediated nature. Therefore, it is imperative to enter into reflective dialogue to effectively develop future participatory and co-creative design practice in virtual settings. Several significant phenomena, oc-curring within virtual workshops, have been identified through focused co-reflection by expert design facilitators. Duality is used as a rhetorical device to explore these phenomena as complex elements that are expressions of dynamic and intertwined influences within the virtual setting. These elements are simul-taneously experienced as both enablers and barriers in virtual workshops, and are negotiated through practice. This paper positions these elements as objects for critical reflection within a propositional model of three expanding degrees of influence; stage, setting, and environment