Shape predicates allow unbounded verification of linearizability using canonical abstraction

Canonical abstraction is a static analysis technique that represents states as 3-valued logical structures, and is able to construct finite representations of systems with infinite statespaces for verification. The granularity of the abstraction can be altered by the definition of instrumentation predicates, which derive their meaning from other predicates. We introduce shape predicates for preserving certain structures of the state during abstraction. We show that shape predicates allow linearizability to be verified for concurrent data structures using canonical abstraction alone, and use the approach to verify a stack and two queue algorithms. This contrasts with previous efforts to verify linearizability with canonical abstraction, which have had to employ other techniques as well

Analysing Scientific Collaborations of New Zealand Institutions using Scopus Bibliometric Data

Scientific collaborations are among the main enablers of development in small national science systems. Although analysing scientific collaborations is a well-established subject in scientometrics, evaluations of scientific collaborations within a country remain speculative with studies based on a limited number of fields or using data too inadequate to be representative of collaborations at a national level. This study represents a unique view on the collaborative aspect of scientific activities in New Zealand. We perform a quantitative study based on all Scopus publications in all subjects for more than 1500 New Zealand institutions over a period of 6 years to generate an extensive mapping of scientific collaboration at a national level. The comparative results reveal the level of collaboration between New Zealand institutions and business enterprises, government institutions, higher education providers, and private not for profit organisations in 2010-2015. Constructing a collaboration network of institutions, we observe a power-law distribution indicating that a small number of New Zealand institutions account for a large proportion of national collaborations. Network centrality concepts are deployed to identify the most central institutions of the country in terms of collaboration. We also provide comparative results on 15 universities and Crown research institutes based on 27 subject classifications.Comment: 10 pages, 15 figures, accepted author copy with link to research data, Analysing Scientific Collaborations of New Zealand Institutions using Scopus Bibliometric Data. In Proceedings of ACSW 2018: Australasian Computer Science Week 2018, January 29-February 2, 2018, Brisbane, QLD, Australi

The effects of feed composition and level on lactational performance in rats and dairy cows: a basic approach to feed description

An investigation into the effects of feed composition on lactational performance was carried out using rats and cows. A graphical representation of the feed as a triangle was used to aid the interpretation of results. The first rat experiment showed that, on high protein feeds, the lactational performance of rats is not depressed when offered feeds of very low carbohydrate content. This was substantiated by the other rat experiments. When carbohydrate in the feed was replaced by fat at low protein content (rat experiment 2) there was a large depression in lactational performance, effectively a cessation of milk production. The interaction between the three feed components protein, carbohydrate, and fat was highly significant. The hypothesis that maternal heat production was limiting food intake was advanced. The third rat experiment used feeds whose composition was marginal in relation to lactational success. The feeds also allowed comparison between feeds of constant nutrient:energy ratio. The results of this experiment indicated that there is an extremely abrupt threshold in feed composition for adequate lactation. This effect could not be attributed to any one nutrient:energy ratio. This experiment also showed the importance of maternal body reserves in support of lactation. A model was developed to explore the hypothesis that maternal heat production was limiting performance, however this model failed. An experiment using sheep was conducted in order to permit prediction of the volatile fatty acid proportions arising from a range of feeds. This experiment was designed to allow application of the rat work to dairy cows. A dairy cow trial was conducted, to compare different feed types and feeding levels. The results of this trial showed no effect of feed type on lactational performance. A linear relationship between food intake and level of milk production was found. This included an effect of feeding level on rate of decline in milk yield. All these findings are discussed in detail

Webs of influence: Investigating the effects of the forest mycorrhizosphere on soil carbon storage in a changing world

Anthropogenic climate change is broadly accepted to be the biggest threat to ecosystems in the 21st century, with the most rapid change occurring in Arctic regions. It is necessary to understand the consequences of on-going warming, such as changing vegetation and northward advance of Arctic treelines, as well as examining the robustness of proposed mitigation strategies, such as intensified tree planting. Using field based approaches in soil carbon rich sub-Arctic and high latitude boreal regions, I found that Betula pubescens roots and associated mycorrhizal fungi extend 3-4.5 m away from trees, thereby covering open forest gaps, possibly creating a ‘wood-wide-web’. However, I found no evidence of common mycelial networks between trees or the understorey in these forests. My findings indicate consistent high production of roots and mycorrhizas throughout the forest floor, coupled with declining soil organic carbon (SOC) stocks with increasing distance from trees. In the Scottish uplands, with comparable tree and understorey species, I found that planting B. pubescens onto heather moorland leads to a 58 and 50% loss of SOC stocks 12 and 39 years after planting, resulting in no net gain in ecosystem C. Long term tree planting experiments provide empirical evidence for the consequences of tree planting schemes as a climate change mitigation strategy and the potential effects of warming-driven encroachment of Arctic treeline forests onto globally important ericaceous soil carbon stores. Combined, my results show how B. pubescens mycorrhizospheres - their roots and associated mycorrhizas - effectively explore throughout the forest floor and shape the spatial dynamics and depletion of soil carbon stocks in Arctic and boreal regions most vulnerable to climate change. Furthermore, this work suggests that, although urgent action on climate change is needed, awareness of the ecological context is crucial if planting trees is to be a robust strategy for climate change mitigation

A modal proof theory for final polynomial coalgebras

AbstractAn infinitary proof theory is developed for modal logics whose models are coalgebras of polynomial functors on the category of sets. The canonical model method from modal logic is adapted to construct a final coalgebra for any polynomial functor. The states of this final coalgebra are certain “maximal” sets of formulas that have natural syntactic closure properties.The syntax of these logics extends that of previously developed modal languages for polynomial coalgebras by adding formulas that express the “termination” of certain functions induced by transition paths. A completeness theorem is proven for the logic of functors which have the Lindenbaum property that every consistent set of formulas has a maximal extension. This property is shown to hold if the deducibility relation is generated by countably many inference rules.A counter-example to completeness is also given. This is a polynomial functor that is not Lindenbaum: it has an uncountable set of formulas that is deductively consistent but has no maximal extension and is unsatisfiable, even though all of its countable subsets are satisfiable

Four New Cestode Species from the Spiral Intestine of the Round Stingray, \u3ci\u3eUrobatis halleri\u3c/i\u3e, in the Northern Gulf of California, Mexico

The spiral intestines of 40 specimens of Urobatis halleri from the northern Gulf of California, Mexico, were examined for cestodes. Four new species, Rhinebothrium chollaensis n. sp., Rhinebothrium gravidum n. sp., Eutetrarhynchus cortezensis n. sp., and Prochristianella minima n. sp., are described. This is the first record of these 3 genera in the Gulf of California and the first report of Eutetrarhynchus in U. halleri

On-farm estimation of energy balance in dairy cows using only frequent body weight measurements and body condition score

AbstractPrecise energy balance estimates for individual cows are of great importance to monitor health, reproduction, and feed management. Energy balance is usually calculated as energy input minus output (EBinout), requiring measurements of feed intake and energy output sources (milk, maintenance, activity, growth, and pregnancy). Except for milk yield, direct measurements of the other sources are difficult to obtain in practice, and estimates contain considerable error sources, limiting on-farm use. Alternatively, energy balance can be estimated from body reserve changes (EBbody) using body weight (BW) and body condition score (BCS). Automated weighing systems exist and new technology performing semi-automated body condition scoring has emerged, so frequent automated BW and BCS measurements are feasible. We present a method to derive individual EBbody estimates from frequently measured BW and BCS and evaluate the performance of the estimated EBbody against the traditional EBinout method. From 76 Danish Holstein and Jersey cows, parity 1 or 2+, on a glycerol-rich or a whole grain-rich total mixed ration, BW was measured automatically at each milking. The BW was corrected for the weight of milk produced and for gutfill. Changes in BW and BCS were used to calculate changes in body protein, body lipid, and EBbody during the first 150d in milk. The EBbody was compared with the traditional EBinout by isolating the term within EBinout associated with most uncertainty; that is, feed energy content (FEC); FEC=(EBbody+EMilk+EMaintenance+Eactivity)/dry matter intake, where the energy requirements are for milk produced (EMilk), maintenance (EMaintenance), and activity (EActivity). Estimated FEC agreed well with FEC values derived from tables (the mean estimate was 0.21MJ of effective energy/kg of dry matter or 2.2% higher than the mean table value). Further, the FEC profile did not suggest systematic bias in EBbody with stage of lactation. The EBbody estimated from daily BW, adjusted for milk and meal-related gutfill and combined with frequent BCS, can provide a successful tool. This offers a pragmatic solution to on-farm calculation of energy balance with the perspective of improved precision under commercial conditions