The Arabana people, water and developing cultural indicators for country

Water is of paramount importance to the Arabana people who live in the Kati Thanda-Lake Eyre region. Assessing the ongoing condition of aquatic ecosystems is an important part of management. Development of indicator frameworks that can incorporate both scientific and cultural values can ensure Indigenous involvement in management, but also facilitate ways in which local and traditional knowledge can be acknowledged as being of value. This project aimed to identify and document the values and indicators for water systems held by the Arabana people with the view to developing ideas about how future assessments across the whole region may: (i) engage with and then, (ii) build a template for cultural indicators across the whole region. This project was implemented using Indigenist and participant methodologies. Arabana people were employed as co-researchers. Three field trips and meetings were held to identify Arabana values for, and indicators about, water in their country. Results indicate that Arabana people value water in multiple ways including for survival, culture and identity. Interestingly, Arabana people also valued water variability and its absence: historical, dry or degraded water sites were noted as significant. Arabana people used a number of indicators or ‘signs’ to assess the ongoing condition of a site. This included flora, fauna, soil, knowledge, history, use, and pressure indicators. In many ways, the cultural indicators used by Arabana people have complementarity with scientific indicators and thus have potential to be built on and then implemented in conjunction with other indicator suites. A cultural indicator schemata is presented as is a co-engagement model for use in wider assessments with other Indigenous groups. However, this research concludes that it is not possible to develop a generic template for integration of all indicators across the region and questions whether or not this is really necessary. Ultimately, what is required is funding and investment into each Indigenous group across the Kati Thanda–Lake Eyre region to support each group to develop their own specific schemata (based potentially on the one we suggest here), and then allocation of funds to train and employ Indigenous people to implement them. The knowledge set built over time in this manner, especially if grounded in the principles of co-existence rather than integration, will also facilitate the conditions for effective and adaptive management. It will be a true complement to scientific indicators and knowledge, while respecting and incorporating Indigenous people aspirations in the region.Nursey-Bray. Melissa, Arabana Aboriginal Corporation, Primary Industries and Regions (SA), SARD

From Forbidden Coronal Lines to Meaningful Coronal Magnetic Fields

We review methods to measure magnetic fields within the corona using the polarized light in magnetic-dipole (M1) lines. We are particularly interested in both the global magnetic-field evolution over a solar cycle, and the local storage of magnetic free energy within coronal plasmas. We address commonly held skepticisms concerning angular ambiguities and line-of-sight confusion. We argue that ambiguities are in principle no worse than more familiar remotely sensed photospheric vector-fields, and that the diagnosis of M1 line data would benefit from simultaneous observations of EUV lines. Based on calculations and data from eclipses, we discuss the most promising lines and different approaches that might be used. We point to the S-like [Fe {\sc XI}] line (J=2 to J=1) at 789.2nm as a prime target line (for ATST for example) to augment the hotter 1074.7 and 1079.8 nm Si-like lines of [Fe {\sc XIII}] currently observed by the Coronal Multi-channel Polarimeter (CoMP). Significant breakthroughs will be made possible with the new generation of coronagraphs, in three distinct ways: (i) through single point inversions (which encompasses also the analysis of MHD wave modes), (ii) using direct comparisons of synthetic MHD or force-free models with polarization data, and (iii) using tomographic techniques.Comment: Accepted by Solar Physics, April 201

Regional scale evaluation of nitrate fluctuations in groundwater using cluster analysis and standardised hydrometeorological indices

Temporal fluctuations in nitrate in groundwater can result in concentrations temporarily exceeding drinking water standards. This can bring about the need for costly water treatment or blending. Despite this, the extent and potential controls on these fluctuations are poorly understood, particularly at regional to national scales. Applied to Southeast England (UK), here we develop the first application of cluster analysis and standardised hydrometeorological indices to evaluate nitrate fluctuations in groundwater at the regional scale. Hierarchical and K-means cluster analysis of 96 groundwater nitrate time series for the period 1995–2022 showed that nitrate time series can be divided into 4 clusters: (1) long term increasing trends (n = 23, mean trend = 0.26 mg NO3/l/a), (2) long term decreasing trends (n = 19, mean trend = − 0.65 mg NO3/l/a), (3) long term increasing trends with seasonal fluctuations (n = 24, mean trend = 0.29 mg NO3/l/a) and (4) long term increasing trends superimposed on near-decadal scale fluctuations (n = 30, mean trend = 0.22 mg NO3/l/a). Boreholes in cluster 1 appear to be deeper than boreholes in cluster 2. In comparison to shallower boreholes, deeper boreholes are likely to be intersecting longer groundwater flow systems where nitrate concentrations are affected by historic “legacy nitrate” leaching. There is weak spatial coherence in the clustering, with clusters 3 and 4 present in the South and North Downs respectively. Cross-correlation analysis between groundwater nitrate time series with precipitation and groundwater level indices showed that rapid seasonal fluctuations in nitrate concentrations in cluster 3 in the South Downs are associated with rapidly responding groundwater level fluctuation. This is likely due to the highly fractured and faulted nature of the Chalk aquifer in this area. This is in contrast with the slower near-decadal fluctuations in cluster 4 in the North Downs. The strongest correlations between groundwater levels and nitrate concentrations in cluster 3 occurred when cross-correlating at a lag of zero months, which would suggest that matrix diffusion is unlikely to be a significant control on nitrate seasonality. Seasonal fluctuations in nitrate concentrations are likely to be associated with a combination of piston displacement at the water table and changing groundwater flow paths to the borehole. Future climate change may change the magnitude and timing of seasonal fluctuations caused by these processes. The methodology developed here is generic and can be applied wherever there is a large body of groundwater nitrate time series data

Properties of the random field Ising model in a transverse magnetic field

We consider the effect of a random longitudinal field on the Ising model in a transverse magnetic field. For spatial dimension $d > 2$, there is at low strength of randomness and transverse field, a phase with true long range order which is destroyed at higher values of the randomness or transverse field. The properties of the quantum phase transition at zero temperature are controlled by a fixed point with no quantum fluctuations. This fixed point also controls the classical finite temperature phase transition in this model. Many critical properties of the quantum transition are therefore identical to those of the classical transition. In particular, we argue that the dynamical scaling is activated, i.e, the logarithm of the diverging time scale rises as a power of the diverging length scale

Persistence in a Stationary Time-series

We study the persistence in a class of continuous stochastic processes that are stationary only under integer shifts of time. We show that under certain conditions, the persistence of such a continuous process reduces to the persistence of a corresponding discrete sequence obtained from the measurement of the process only at integer times. We then construct a specific sequence for which the persistence can be computed even though the sequence is non-Markovian. We show that this may be considered as a limiting case of persistence in the diffusion process on a hierarchical lattice.Comment: 8 pages revte

Adaptive cluster expansion for the inverse Ising problem: convergence, algorithm and tests

We present a procedure to solve the inverse Ising problem, that is to find the interactions between a set of binary variables from the measure of their equilibrium correlations. The method consists in constructing and selecting specific clusters of variables, based on their contributions to the cross-entropy of the Ising model. Small contributions are discarded to avoid overfitting and to make the computation tractable. The properties of the cluster expansion and its performances on synthetic data are studied. To make the implementation easier we give the pseudo-code of the algorithm.Comment: Paper submitted to Journal of Statistical Physic

Spin-Peierls transition in NaV2O5 in high magnetic fields

We investigate the magnetic field dependence of the spin-Peierls transition in NaV$_2$O$_5$ in the field range 16T-30T. The transition temperature exhibits a very weak variation with the field, suggesting a novel mechanism for the formation of the spin-Peierls state. We argue that a charge ordering transition accompanied by singlet formation is consistent with our observations.Comment: 4 pages, 3 figures, final version to appear in Phys. Rev. B (RC

Female Sex but Not Oestrogen Receptor Expression Predicts Survival in Advanced Gastroesophageal Adenocarcinoma—A Post-hoc Analysis of the GO2 Trial

Gastroesophageal adenocarcinoma is a disease of older adults that is associated with a very poor prognosis. It is less common and has better outcomes in females. The reason for this is unknown but may relate to signalling via the main oestrogen receptors (ER) α and β. In this study, we sought to investigate this using the GO2 clinical trial patient cohort. GO2 recruited older and/or frail patients with advanced gastroesophageal cancer. Immunohistochemistry was performed on tumour samples from 194 patients. The median age of the population was 76 years (range 52–90), and 25.3% were female. Only one (0.5%) tumour sample was positive for ERα, compared to 70.6% for ERβ expression. There was no survival impact according to ERβ expression level. Female sex and younger age were associated with lower ERβ expression. Female sex was also associated with improved overall survival. To our knowledge, this is the largest study worldwide of ER expression in a cohort of patients with advanced gastroesophageal adenocarcinoma. It is also unique, given the age of the population. We have demonstrated that female sex is associated with better survival outcomes with palliative chemotherapy but that this does not appear to be related to ER IHC expression. The differing ER expression according to age supports the concept of a different disease biology with age