Relations between M\"obius and coboundary polynomial

It is known that, in general, the coboundary polynomial and the M\"obius polynomial of a matroid do not determine each other. Less is known about more specific cases. In this paper, we will try to answer if it is possible that the M\"obius polynomial of a matroid, together with the M\"obius polynomial of the dual matroid, define the coboundary polynomial of the matroid. In some cases, the answer is affirmative, and we will give two constructions to determine the coboundary polynomial in these cases.Comment: 12 page

Are anticardiolipin antibodies responsible for some of the complications of severe acute Plasmodium falciparum malaria?

What were first called simply false-positive Wassermann reactions and then lupus anticoagulant are now known as antiphospholipid or anticardiolipin antibodies (ACA). These are known to cause a tendency to thrombosis and are frequently present in many neurological conditions and infections. The pathological significance of these antibodies in acute infections, if any, is unknown. We investigated the presence ofthese antibodies in Plasmodium falciparum malaria in an endemic area in Natal/KwaZulu, and attempted to correlate  the presence of this antibody with cerebral manifestations. Immunoglobulin G-anticardiolipin antibodies measured by enzyme-linked immunosorbent assay occurred significantly more frequently in 62 patients with acute Plasmodium falciparum malaria (33,9%) than in 37 control subjects (2,7%) (P < 0,0001). There was no significant difference in the mean parasite loads in those patients who were positive for ACA (1,75%) and those who were negative (1,59%) (P = 0,83). No correlation was found between parasite load and ACA levels in the patient group, or between the number of cerebral manifestations in patients with and without the antibody. The frequency of  splenomegaly was not significantly different in patients with and without ACA (P =0,06). We conclude that there is a high prevalence of ACA in acute falciparum malaria. The pathological significance of this antibody and its relationship to complications, especially cerebral ones, warrant greater attention and may improve the understanding of cerebral malaria and its management

Applying the concept of ecohydrological equilibrium to predict steady state leaf area index

Leaf area index (LAI) is a key variable in modeling terrestrial vegetation because it has a major impact on carbon and water fluxes. However, several recent intercomparisons have shown that modeled LAI differs significantly among models and between models and satellite‐derived estimates. Empirical studies show that LAI is strongly related to precipitation. This observation is predicted by the ecohydrological equilibrium theory, which provides an alternative means to predict steady state LAI. We implemented this theory in a simple optimization model. We hypothesized that, when water availability is limited, plants should adjust steady state LAI and stomatal behavior to maximize net canopy carbon export, under the constraint that canopy transpiration is a fixed fraction of total precipitation. We evaluated the predicted LAI (Lopt) for Australia against ground‐based observations of LAI at 135 sites and continental‐scale satellite‐derived estimates. For the site‐level data, the root‐mean‐square error of predicted Lopt was 1.07 m2 m−2, similar to the root‐mean‐square error of a comparison of the data against 9‐year mean satellite‐derived LAI (Lsat) at those sites. Continentally, Lopt had an R2 of 0.7 when compared to Lsat. The predicted Lopt increased continental‐wide with rising atmospheric [CO2] over 1982–2010, which agreed with satellite‐derived estimations, while the predicted stomatal behavior responded differently in dry and wet regions. Our results indicate that long‐term equilibrium LAI can be successfully predicted from a simple application of ecohydrological theory. We suggest that this theory could be usefully incorporated into terrestrial vegetation models to improve their predictions of LAI

Upside-down fluxes Down Under: CO2 net sink in winter and net source in summer in a temperate evergreen broadleaf forest

Predicting the seasonal dynamics of ecosystem carbon fluxes is challenging in broadleaved evergreen forests because of their moderate climates and subtle changes in canopy phenology. We assessed the climatic and biotic drivers of the seasonality of net ecosystem–atmosphere CO2 exchange (NEE) of a eucalyptus-dominated forest near Sydney, Australia, using the eddy covariance method. The climate is characterised by a mean annual precipitation of 800mm and a mean annual temperature of 18°C, hot summers and mild winters, with highly variable precipitation. In the 4-year study, the ecosystem was a sink each year (−225gCm−2yr−1 on average, with a standard deviation of 108gCm−2yr−1); inter-annual variations were not related to meteorological conditions. Daily net C uptake was always detected during the cooler, drier winter months (June through August), while net C loss occurred during the warmer, wetter summer months (December through February). Gross primary productivity (GPP) seasonality was low, despite longer days with higher light intensity in summer, because vapour pressure deficit (D) and air temperature (Ta) restricted surface conductance during summer while winter temperatures were still high enough to support photosynthesis. Maximum GPP during ideal environmental conditions was significantly correlated with remotely sensed enhanced vegetation index (EVI; r2 = 0.46) and with canopy leaf area index (LAI; r2= 0.29), which increased rapidly after mid-summer rainfall events. Ecosystem respiration (ER) was highest during summer in wet soils and lowest during winter months. ER had larger seasonal amplitude compared to GPP, and therefore drove the seasonal variation of NEE. Because summer carbon uptake may become increasingly limited by atmospheric demand and high temperature, and because ecosystem respiration could be enhanced by rising temperatures, our results suggest the potential for large-scale seasonal shifts in NEE in sclerophyll vegetation under climate change.The Australian Education Investment Fund, Australian Terrestrial Ecosystem Research Network, Australian Research Council and Hawkesbury Institute for the Environment at Western Sydney University supported this work. We thank Jason Beringer, Helen Cleugh, Ray Leuning and Eva van Gorsel for advice and support. Senani Karunaratne provided soil classification details

Fostering effective early learning (FEEL) study

The 2018 Fostering Effective Early Learning (FEEL) study focuses on the importance of quality, and how to strengthen it in early childhood education and care (ECEC) settings. Extensive research demonstrates that the benefits of ECEC for children are increased when the service provider and educators are highly skilled and participate in professional development (PD), and the service is of high quality. Upskilling the workforce, including in-service professional development, is considered to be a key to improving quality, and can produce substantial and practical improvements for staff and children alike. Building on the existing body of international research, the findings of the Fostering Effective Early Learning (FEEL) study, address the need for quality improvement in ECEC by showing how a particular form of evidence-based in-service PD can produce substantial and practically meaningful improvements in both staff practices and child outcomes. The FEEL study was conducted by the research team from Early Start, University of Wollongong, on behalf on the NSW Department of Education

Reconciling the optimal and empirical approaches to modelling stomatal conductance

Models of vegetation function are widely used to predict the effects of climate change on carbon, water and nutrient cycles of terrestrial ecosystems, and their feedbacks to climate. Stomatal conductance, the process that governs plant water use and carbon uptake, is fundamental to such models. In this paper, we reconcile two long-standing theories of stomatal conductance. The empirical approach, which is most commonly used in vegetation models, is phenomenological, based on experimental observations of stomatal behaviour in response to environmental conditions. The optimal approach is based on the theoretical argument that stomata should act to minimize the amount of water used per unit carbon gained. We reconcile these two approaches by showing that the theory of optimal stomatal conductance can be used to derive a model of stomatal conductance that is closely analogous to the empirical models. Consequently, we obtain a unified stomatal model which has a similar form to existing empirical models, but which now provides a theoretical interpretation for model parameter values. The key model parameter, g1, is predicted to increase with growth temperature and with the marginal water cost of carbon gain. The new model is fitted to a range of datasets ranging from tropical to boreal trees. The parameter g1 is shown to vary with growth temperature, as predicted, and also with plant functional type. The model is shown to correctly capture responses of stomatal conductance to changing atmospheric CO2, and thus can be used to test for stomatal acclimation to elevated CO2. The reconciliation of the optimal and empirical approaches to modelling stomatal conductance is important for global change biology because it provides a simple theoretical framework for analyzing, and simulating, the coupling between carbon and water cycles under environmental change. © 2011 Blackwell Publishing Ltd

Introducing the transnational conflict in Africa dataset

This occasional paper is the counterpart to the paper, ‘Redescribing Transnational Conflict in Africa’ (Twagiramungu et al. 2019). It introduces the transnational conflict in Africa (TCA) dataset, which can be used to study the neglected transnational dimensions of armed conflicts in Africa. The TCA dataset is built by combining, augmenting, and revising several existing datasets, each of which captures some elements of transnational conflict, including interstate wars, external state support in interstate wars, low-intensity confrontations between states, external interventions in civil wars, and external support to rebels or coup-makers. The methodology underlying the TCA is explained and some descriptive statistics concerning the dimensions of transnational conflict in Africa are presented. The final section discusses some challenges and concludes that the conventional wisdom that Africa has experienced little interstate conflict is misleading. In order to fully explain the internationality of wars in Africa, including so-called ‘civil wars’ as well as other forms of political violence such as military coups, one needs to look at regional and interstate dynamics, as opposed to solely dynamics within a country

Measuring interactional quality in pre-school settings: Introduction and validation of the Sustained Shared Thinking and Emotional Wellbeing (SSTEW) scale

Research increasingly acknowledges the importance of high quality interactions that support and extend children’s thinking. Few measurement tools currently exist, however, to capture this specific aspect of process quality. The Sustained Shared Thinking and Emotional Wellbeing (SSTEW) scale was developed to assess interactional quality in early childhood education and care, and it includes dimensions of process quality based on developmental theories and practice in effective settings. This study compared ratings on the SSTEW and Early Childhood Environment Rating Scale – Extension (ECERS-E) to consider the impact of varying levels of curricular and interactional quality on child development in 45 Australian pre-school centres; namely the language, numeracy and socio-behavioural development of 669 children at the end of their pre-school year. Results indicated a level of predictive validity for interactional quality ratings as measured by SSTEW which, while related to curricular quality ratings on ECERS-E, differed in associations across domains of child development

Biological, ecological, conservation and legal information for all species and subspecies of Australian bird

We introduce a dataset of biological, ecological, conservation and legal information for every species and subspecies of Australian bird, 2056 taxa or populations in total. Version 1 contains 230 fields grouped under the following headings: Taxonomy & nomenclature, Phylogeny, Australian population status, Conservation status, Legal status, Distribution, Morphology, Habitat, Food, Behaviour, Breeding, Mobility and Climate metrics. It is envisaged that the dataset will be updated periodically with new data for existing fields and the addition of new fields. The dataset has already had, and will continue to have applications in Australian and international ornithology, especially those that require standard information for a large number of taxa