Simple groups and strong covers

AbstractGiven a finite, nonabelian, simple group S and labelling π as the set of prime divisors of |S|, a set C of character degrees of S strongly covers π if some fixed prime divides every member of C and every prime in π divides at least one member of C. In this article, we classify the simple groups S for which there is such a set.When there is such a set, we associate a strong covering number scn(S) with S by letting this be the cardinality of a smallest set C of degrees which strongly covers π. Finding a set C which strongly covers π establishes an upper bound on scn(S), but in many cases our set C has minimal cardinality, and so scn(S)=|C|. In addition, if cd(S) has a subset C which strongly covers π, C can be chosen so |C|⩽3, showing scn(S)⩽3, and we furthermore classify which simple groups have a strong covering number of 3. For all the sporadic and alternating groups, and several families of groups of Lie type, we calculate the exact strong covering number. Several consequences of these facts are also presented

Molecular Interactions in the Norrin Receptor Complex

The retina has the highest oxygen consumption rate of any tissue type within the body and thus, requires extensive vasculature to supply its needs. The blood vessels supplying this tissue form in a distinct and highly characterized manner, known to be under the control of the Norrin/Frizzled4 signaling pathway. Tetraspanin12 (TSPAN12), a membrane protein, is one of the proteins mediating this pathway, but its role in signaling initiation is largely unknown. I hypothesized that TSPAN12 may positively regulate Norrin/Frizzled4 signaling by promoting protein-protein interactions in the Norrin receptor complex. This study utilized the iDimerize system to survey the function of possible protein interactions among components of the Norrin receptor complex. The goal was to gain insight into which interactions promote signaling and to thereby help identify candidate interactions that may be promoted by TSPAN12. I show that forcing the interactions of Frizzled4 and the co-receptor LRP5 promotes two components of signaling: one is Norrin dependent signaling and the other component is Norrin independent. A point mutation in Frizzled4, M105V, impairs only the Norrin-dependent component of signaling and is rescued by TSPAN12. Along with other evidence, this suggests that TSPAN12 may rescue signaling defects of Frizzled4 M105V by promoting Norrin binding to Frizzled4

“Traduttore, traditore?” Translating human rights into the corporate context

This research is part of a larger PhD studentship Grant, which is funded by the Scottish Graduate School of Social Science (SGSSS) and the Institute of Chartered Accountants Scotland (ICAS).This paper critically investigates the implementation of the UN guiding principles on business and human rights (UNGPs) into the corporate setting through the concept of ‘translation’. In the decade since the creation of the UNGPs, little academic research has focussed specifically on the corporate implementation of human rights. Drawing on qualitative case studies of two multinational corporations—an oil and gas company and a bank—this paper unpacks how human rights are translated into the corporate context. In doing so, the paper focuses on the “resonance dilemma” translators encounter, the strategies used to make human rights understandable and palatable, and the difficulties that emerge from this process. We contend that the process of making human rights understandable and manageable can change their form and content, which may act as an obstacle to human rights realisation and corporate accountability for human rights.Publisher PDFPeer reviewe

National Action Plans on Business and Human Rights:an Experimentalist Governance Analysis

Research for this article was partly funded by Danida, “Realising the SDGS: The role of responsible business”.National Action Plans (NAPs) on business and human rights are a growing phenomenon. Since 2011, 42 such plans have been adopted or are in-development worldwide. By comparison, only 39 general human rights action plans were published between 1993 and 2021. In parallel, NAPs have attracted growing scholarly interest. While some studies highlight their potential to advance national compliance with international norms, others criticise NAPs as cosmetic devices that states use to deflect attention from persisting abuses and needed regulation. In response to wider critiques of international human rights norms, and their failure to exact universal state compliance, experimentalist governance theory highlights the dynamic, dialogic and iterative character of human rights implementation as well as the role of stakeholders. In this article, we apply experimentalist governance theory to evaluate the role and character of business and human rights NAPs. Rather than attempting to evaluate NAPs’ ultimate consequences for rights-holders, which appears premature, we focus on NAPs processes. Specifically, we analyse NAPs processes in twenty-five states against five experimentalist governance criteria relating to (i) stakeholder participation; (ii) agreement on a broad problem definition; (iii) local contextualisation; (iv) monitoring and peer review and (v) periodic revision and learning. According to our findings, NAPs on business and human rights in most states demonstrate resemblance to the traits of experimentalist governance. In particular, our analysis points to the emergence of relatively sophisticated and demanding institutional governance mechanisms within NAPs — including the institutionalisation of complex deliberative processes. Nevertheless, our paper also identifies some significant shortcomings in NAPs, related to the lack of inclusion of vulnerable groups and the lack of explicit indicators and targets.Publisher PDFPeer reviewe

Mechanisms of instabilities of exothermic hypersonic blunt-body flows,

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1968.Vita.Bibliography: leaves 112-117.by John B. McVey.Sc.D

Preliminary Evaluation of a 10 kW Hall Thruster

A 10 kW Hall thruster was characterized over a range of discharge voltages from 300-500 V and a range of discharge currents from 15-23 A. This corresponds to power levels from a low of 4.6 kW to a high of 10.7 kW. Over this range of discharge powers, thrust varied from 278 mN to 524 mN, specific impulse ranged from 1644 to 2392 seconds, and efficiency peaked at approximately 59%. A continuous 40 hour test was also undertaken in an attempt to gain insight with regard to long term operation of the engine. For this portion of the testing the thruster was operated at a discharge voltage of 500 V and a discharge current of 20 A. Steady-state temperatures were achieved after 3-5 hrs and very little variation in performance was detected

The P2X(7 )receptor is a candidate product of murine and human lupus susceptibility loci: a hypothesis and comparison of murine allelic products

Systemic lupus erythematosus and its murine equivalent, modelled in the New Zealand Black and New Zealand White (NZB × NZW)F(1 )hybrid strain, are polygenic inflammatory diseases, probably reflecting an autoimmune response to debris from cells undergoing programmed cell death. Several human and murine loci contributing to disease have been defined. The present study asks whether the proinflammatory purinergic receptor P2X(7), an initiator of a form of programmed cell death known as aponecrosis, is a candidate product of murine and human lupus susceptibility loci. One such locus in (NZB × NZW)F(1 )mice is lbw3, which is situated at the distal end of NZW chromosome 5. We first assess whether NZB mice and NZW mice carry distinct alleles of the P2RX(7 )gene as expressed by common laboratory strains, which differ in sensitivity to ATP stimulation. We then compare the responses of NZB lymphocytes, NZW lymphocytes and (NZB × NZW)F(1 )lymphocytes to P2X(7 )stimulation. NZB and NZW parental strains express the distinct P2X(7)-L and P2X(7)-P alleles of P2RX(7), respectively, while lymphocytes from these and (NZB × NZW)F(1 )mice differ markedly in their responses to P2X(7 )receptor stimulation. NZB mice and NZW mice express functionally distinct alleles of the proinflammatory receptor, P2X(7). We show that current mapping suggests that murine and human P2RX(7 )receptor genes lie within lupus susceptibility loci lbw3 and SLEB4, and we argue that these encode a product with the functional characteristics consistent with a role in lupus. Furthermore, we argue that aponecrosis as induced by P2X(7 )is a cell death mechanism with characteristics that potentially have particular relevance to disease pathogenesis