The algebra of rewriting for presentations of inverse monoids

We describe a formalism, using groupoids, for the study of rewriting for presentations of inverse monoids, that is based on the Squier complex construction for monoid presentations. We introduce the class of pseudoregular groupoids, an example of which now arises as the fundamental groupoid of our version of the Squier complex. A further key ingredient is the factorisation of the presentation map from a free inverse monoid as the composition of an idempotent pure map and an idempotent separating map. The relation module of a presentation is then defined as the abelianised kernel of this idempotent separating map. We then use the properties of idempotent separating maps to derive a free presentation of the relation module. The construction of its kernel - the module of identities - uses further facts about pseudoregular groupoids.Comment: 22 page

High-temperature environments of human evolution in East Africa based on bond ordering in paleosol carbonates

Many important hominid-bearing fossil localities in East Africa are in regions that are extremely hot and dry. Although humans are well adapted to such conditions, it has been inferred that East African environments were cooler or more wooded during the Pliocene and Pleistocene when this region was a central stage of human evolution. Here we show that the Turkana Basin, Kenya—today one of the hottest places on Earth—has been continually hot during the past 4 million years. The distribution of ^(13)C-^(18)O bonds in paleosol carbonates indicates that soil temperatures during periods of carbonate formation were typically above 30 °C and often in excess of 35 °C. Similar soil temperatures are observed today in the Turkana Basin and reflect high air temperatures combined with solar heating of the soil surface. These results are specific to periods of soil carbonate formation, and we suggest that such periods composed a large fraction of integrated time in the Turkana Basin. If correct, this interpretation has implications for human thermophysiology and implies a long-standing human association with marginal environments

Groupoids and the algebra of rewriting in group presentations

Presentations of groups by rewriting systems (that is, by monoid presentations), have been fruitfully studied by encoding the rewriting system in a $2$--complex -- the Squier complex -- whose fundamental groupoid then describes the derivation of consequences of the rewrite rules. We describe a reduced form of the Squier complex, investigate the structure of its fundamental groupoid, and show that key properties of the presentation are still encoded in the reduced form.Comment: 15 page

Indenture, Marshall County, MS, 1 April 1853

https://egrove.olemiss.edu/aldrichcorr_c/1065/thumbnail.jp

Boundary effect of a partition in a quantum well

The paper wishes to demonstrate that, in quantum systems with boundaries, different boundary conditions can lead to remarkably different physical behaviour. Our seemingly innocent setting is a one dimensional potential well that is divided into two halves by a thin separating wall. The two half wells are populated by the same type and number of particles and are kept at the same temperature. The only difference is in the boundary condition imposed at the two sides of the separating wall, which is the Dirichlet condition from the left and the Neumann condition from the right. The resulting different energy spectra cause a difference in the quantum statistically emerging pressure on the two sides. The net force acting on the separating wall proves to be nonzero at any temperature and, after a weak decrease in the low temperature domain, to increase and diverge with a square-root-of-temperature asymptotics for high temperatures. These observations hold for both bosonic and fermionic type particles, but with quantitative differences. We work out several analytic approximations to explain these differences and the various aspects of the found unexpectedly complex picture.Comment: LaTeX (with iopart.cls, iopart10.clo and iopart12.clo), 28 pages, 17 figure

Anticipated impacts of voluntary assisted dying legislation on nursing practice

Background: The Voluntary Assisted Dying Act 2017 passed into law in Victoria, Australia, on the 29 November 2017. Internationally, nurses have been shown to be intimately involved in patient care throughout the voluntary assisted dying process. However, there is a paucity of research exploring Australian nurses’ perspectives on voluntary assisted dying and, in particular, how Victorian nurses anticipate the implementation of this ethically controversial legislation will impact their professional lives. Objectives: To explore Victorian nurses’ expectations of the ethical and practical impacts the voluntary assisted dying legislation will have on their professional lives. Research design: This qualitative study analysed nurses’ free text responses collected as part of a larger mixed methods online survey investigating staff views on the Voluntary Assisted Dying Act. Data were collected during the period between the passing of the voluntary assisted dying legislation and the start date and were analysed using inductive content analysis. Participants and research context: Free text survey responses were analysed from 1873 nurses employed across seven Victorian health services located in both metropolitan and regional areas of the state. Ethical considerations: The study obtained research ethics approval and all participants were informed of the voluntary and anonymous nature of their participation. Findings: This study identified three broad areas of Victorian nurses’ professional lives that they expected to be impacted by the implementation of voluntary assisted dying: professional identity, career development and workplace relationships. Conclusion: Participants anticipate diverse and nursing-specific impacts of the implementation of voluntary assisted dying in Victoria. Their insights can inform health services in jurisdictions considering or already implementing voluntary assisted dying, to develop policies, procedures and staff training programmes that safeguard the well-being and legal rights of their nursing staff

Curating media learning: Towards a porous expertise

This article combines research results from a range of projects with two consistent themes. Firstly, we explore the potential for curation to offer a productive metaphor for the convergence of digital media learning across and between home / lifeworld and formal educational / systemworld spaces – or between the public and private spheres. Secondly, we draw conclusions from these projects to argue that the acceptance of transmedia literacy practices as a site for rich educational work – in media education and related areas – can only succeed if matched by a convergence of a more porous educator–student expertise

Ordered groupoids and the holomorph of an inverse semigroup

We present a construction for the holomorph of an inverse semigroup, derived from the cartesian closed structure of the category of ordered groupoids. We compare the holomorph with the monoid of mappings that preserve the ternary heap operation on an inverse semigroup: for groups these two constructions coincide. We present detailed calculations for semilattices of groups and for the polycyclic monoids.Comment: 16 page