Hopf algebras and Markov chains: Two examples and a theory

The operation of squaring (coproduct followed by product) in a combinatorial Hopf algebra is shown to induce a Markov chain in natural bases. Chains constructed in this way include widely studied methods of card shuffling, a natural "rock-breaking" process, and Markov chains on simplicial complexes. Many of these chains can be explictly diagonalized using the primitive elements of the algebra and the combinatorics of the free Lie algebra. For card shuffling, this gives an explicit description of the eigenvectors. For rock-breaking, an explicit description of the quasi-stationary distribution and sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes will only appear on the version on Amy Pang's website, the arXiv version will not be updated.

Neuropathological Findings In Chronic Relapsing Experimental Allergic Neuritis Induced In The Lewis Rat By Inoculation With Intradural Root Myelin And Treatment With Low Dose Cyclosporin A

Experimental allergic neuritis (EAN) was induced in Lewis rats by inoculation with bovine intradural root myelin and adjuvants. Rats treated with subcutaneous cyclosporin A (CsA) (4mg/kg on 3 days per week from the day of inoculation until day 29) developed a chronic relapsing course. Tissues from the spinal cord, nerve roots, dorsal root ganglia and sciatic nerve of CsA-treated rats sampled during relapses and remissions were studied during or after episodes of acute EAN. Both control and CsA-treated animals studied in the first episode of EAN had evidence of inflammation and primary demyelination of the nerve roots and dorsal root ganglia. In control and CsA-treated animals in the second episode there was severe inflammation and demyelination and remyelination in the spinal nerves and sciatic nerves and dorsal columns of the spinal cord, particularly in later stages of the disease. In later episodes there was less inflammation, but there was continuing demyelination and onion bulbs were present. In animals sampled after recovery from chronic relapsing EAN onion bulbs were present. Occasional small onion bulbs were also observed in control animals that were inoculated with higher doses of myelin. Plasma cells were present in the inflammatory lesions of later episodes. Mast cells were also observed at different stages of the disease. We conclude that the CsA form of chronic relapsing EAN has clinical and pathological similarities with the human disease, chronic inflammatory demyelinating polyradiculoneuropathy

Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction

A representational predicament for a subordinate vis-à-vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. © 2013 Copyright Taylor and Francis Group, LLC

Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial

Background Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear. Methods RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047. Findings Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths. Interpretation Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population

Comparison of methods used to characterize water imbibition in hard-to-cook beans

The traditional gravimetric and volumetric methods of measuring water imbibition were compared to a new method, water-holding capacity, to study water uptake in black bean cotyledons with and without the hard-to-cook defect. Water-holding capacity was found to be more reliable in measuring water taken up by the cotyledon since the former methods measure gross water uptake, including a layer of bulk water existing between the seedcoat and cotyledons of hard-to-cook beans. Total water uptake, as measure by the water absorption method was greatest for hard-to-cook beans. Using the water-holding capacity method, however, hard-to-cook beans were found to bind approximately 25% less water during soaking than control beans

Global Universal Service and International Settlement Reform

The objective of this paper is to analyze the international settlement system and its implications for the development of a global telecommunications network in an industry scenario that is moving beyond international accounting rates. The international dimension of funding developing countries' universal service policies is then discussed. It is pointed out that increasing competition in international markets, diverting traffic flows and retail price collection from developing to rich countries could lower the total revenue that the former obtain from international services, even when the received net settlement payments increase. The expected international settlement reforms asked for by the ITU and the US federal regulator could also intensify this phenomenon. Therefore, our conclusion is that such reforms may require adequate safe-guards to deliver financial support to developing world network infrastructure, also considering the positive externalities accruing to rich countries. Zusammenfassung Globaler Universaldienst und Reform der internationalen Ausgleichszahlungen in der Telekommunikation Der vorliegende Aufsatz analysiert das internationale System der Ausgleichszahlungen und seine Auswirkungen auf die Entwicklung eines globalen Telekommunikationsnetzwerkes. Dies geschieht anhand eines Szenarios, das über internationale Verrechnungssätze hinausgeht. Die internationale Dimension der Finanzierung von Universaldienststrategien in Entwicklungsländern wird anschließend diskutiert. Es wird darauf hingewiesen, dass der sich verschärfende Wettbewerb auf internationalen Märkten, der Kommunikationsströme und Einnahmen von den sich entwickelnden auf die reichen Länder verlagert, zur Verringerung der Gesamteinnhamen der ärmeren Länder führen kann, auch wenn die erhaltenen Netto-Ausgleichszahlungen steigen. Die erwartete Reform des Systems der Ausgleichszahlungen, das die ITU und die US-amerikanische Regulierungsbehörde anstreben, könnten dieses Phänomen weiter verstärken. Die Schlussfolgerung der Autoren lautet daher, dass diese Reformen adäquatebegelitende Maßnahmen erfordern, die den Aufbau einer internationalen Netzinfrastruktur finanziell unterstützen. Hier sollten auch die positiven Externalitäten, die den reichen Ländern zugute kommen, berücksichtigt werden