On groups that have normal forms computable in logspace

We consider the class of finitely generated groups which have a normal form computable in logspace. We prove that the class of such groups is closed under finite extensions, finite index subgroups, direct products, wreath products, and also certain free products, and includes the solvable Baumslag-Solitar groups, as well as non-residually finite (and hence non-linear) examples. We define a group to be logspace embeddable if it embeds in a group with normal forms computable in logspace. We prove that finitely generated nilpotent groups are logspace embeddable. It follows that all groups of polynomial growth are logspace embeddable.Comment: 24 pages, 1 figure. Minor corrections from previous versio

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

Semigroup expansions using the derived category, kernel, and Malcev products

AbstractThree new classes of expansions are defined in this paper. More precisely, three different expansions are associated to each semigroup variety V. It is shown that several previously defined expansions can be viewed as specific examples of these constructions, or slight variants there of. This method is then used to “smooth” an already existing expansion to one which is guaranteed to be functorial and is maximal in a sense that will be made precise. Perhaps more importantly, this method of construction provides a large resource of expansions to be used as needed in the future

Holonomy Embedding for Arbitrary Stable Semigroups

Original article can be found at: http://ejournals.wspc.com.sg/journals/ijac/mkt/archive.shtml Copyright World Scientific Publishing Company. DOI: 10.1142/S0218196702001206 [Full text of this article is not available in the UHRA]We show how the Rhodes expansion Ŝ of any stable semigroup S embeds into the cascade integral (a natural generalization of the wreath product) of permutation-reset transformation semigroups with zero adjoined. The permutation groups involved are exactly the Schützenberger groups of the -classes of S. Since S ←← Ŝ is an aperiodic map via which all subgroups of S lift to Ŝ, this results in a strong Krohn–Rhodes–Zeiger decomposition for the entire class of stable semigroups. This class includes all semigroups that are finite, torsion, finite -above, compact Hausdorff, or relatively free profinite, as well as many other semigroups. Even if S is not stable, one can expand it using Henckell's expansion and then apply our embedding. This gives a simplified proof of the Holonomy Embedding theorem for all semigroups.Peer reviewe

Measuring engagement in advance care planning: a cross-sectional multicentre feasibility study

ObjectivesTo assess the feasibility, acceptability and clinical sensibility of a novel survey, the advance care planning (ACP) Engagement Survey, in various healthcare settings.SettingA target sample of 50 patients from each of primary care, hospital, cancer care and dialysis care settings.ParticipantsA convenience sample of patients without cognitive impairment who could speak and read English was recruited. Patients 50 and older were eligible in primary care; patients 80 and older or 55 and older with clinical markers of advanced chronic disease were recruited in hospital; patients aged 19 and older were recruited in cancer and renal dialysis centres.OutcomesWe assessed feasibility, acceptability and clinical sensibility of the ACP Engagement Survey using a 6-point scale. The ACP Engagement Survey measures ACP processes (knowledge, contemplation, self-efficacy and readiness) on 5-point Likert scales and actions (yes/no).Results196 patients (38-96 years old, 50.5% women) participated. Mean (±SD) time to administer was 48.8±19.6 min. Mean acceptability scores ranged from 3.2±1.3 in hospital to 4.7±0.9 in primary care, and mean relevance ranged from 3.5±1.0 in hospital to 4.9±0.9 in dialysis centres (p<0.001 for both). The mean process score was 3.1±0.6 and the mean action score was 11.2±5.6 (of a possible 25).ConclusionsThe ACP Engagement Survey demonstrated feasibility and acceptability in outpatient settings but was less feasible and acceptable among hospitalised patients due to length. A shorter version may improve feasibility. Engagement in ACP was low to moderate

Effect of an Interactive Website to Engage Patients in Advance Care Planning in Outpatient Settings

PurposeOnline programs may help to engage patients in advance care planning in outpatient settings. We sought to implement an online advance care planning program, PREPARE (Prepare for Your Care; http://www.prepareforyourcare.org), at home and evaluate the changes in advance care planning engagement among patients attending outpatient clinics.MethodsWe undertook a prospective before-and-after study in 15 primary care clinics and 2 outpatient cancer centers in Canada. Patients were aged 50 years or older (primary care) or 18 years or older (cancer care) and free of cognitive impairment. They used the PREPARE website over 6 weeks, with reminders sent at 2 or 4 weeks. We used the 55-item Advance Care Planning Engagement Survey, which measures behavior change processes (knowledge, contemplation, self-efficacy, readiness) on 5-point scales and actions relating to substitute decision makers, quality of life, flexibility for the decision maker, and asking doctors questions on an overall scale from 0 to 21; higher scores indicate greater engagement.ResultsIn total, 315 patients were screened and 172 enrolled, of whom 75% completed the study (mean age = 65.6 years, 51% female, 35% had cancer). The mean behavior change process score was 2.9 (SD 0.8) at baseline and 3.5 (SD 0.8) at follow-up (mean change = 0.6; 95% CI, 0.49-0.73); the mean action measure score was 4.0 (SD 4.9) at baseline and 5.2 (SD 5.4) at follow-up (mean change = 1.2; 95% CI, 0.54-1.77). The effect size was moderate (0.75) for the former and small (0.23) for the latter. Findings were similar in both primary care and cancer care populations.ConclusionsImplementation of the online PREPARE program in primary care and cancer care clinics increased advance care planning engagement among patients