Distribution and Density of Vegetative Hydrilla Propagules in the Sediments of Two New Zealand Lakes

The distribution and density of hydrilla (Hydrilla verticillata (L.f.)Royle) turions and tubers in two New Zealand lakes were assessed by sampling cores of sediment from Lakes Tutira and Waikapiro each year from 1994 to 1997. Turion and tuber density differed with water depth, with maximum numbers of tubers and turions found in the 1-2 m and 1.5-4m water depth ranges respectively. A high turion to tuber ratio was observed, with turions accounting for over 80% of propagules. The relatively low numbers of turions and tubers compared with other reports, and the distribution of most tubers within the shallow water is likely to be associated with black swan grazing (Cygnus atratus Latham), with maintains a canopy of hydrilla consistently 1 m below the water surface

The Rise and Fall of Water Net (Hydrodictyon reticulatum) in New Zealand

During the late 1980s to early 1990s a range of aquatic habitats in the central North Island of New Zealand were invaded by the filamentous green alga, water net Hydrodictyon reticulatum (Linn. Lagerheim). The alga caused significant economic and recreational impacts at major sites of infestation, but it was also associated with enhanced invertebrate numbers and was the likely cause of an improvement in the trout fishery. The causes of prolific growth of water net and the range of control options pursued are reviewed. The possible causes of its sudden decline in 1995 are considered, including physical factors, increase in grazer pressure, disease, and loss of genetic vigour

Developing a novel comprehensive framework for the investigation of cellular and whole heart electrophysiology in the in situ human heart: Historical perspectives, current progress and future prospects

Understanding the mechanisms of fatal ventricular arrhythmias is of great importance. In view of the many electrophysiological differences that exist between animal species and humans, the acquisition of basic electrophysiological data in the intact human heart is essential to drive and complement experimental work in animal and in-silico models. Over the years techniques have been developed to obtain basic electrophysiological signals directly from the patients by incorporating these measurements into routine clinical procedures which access the heart such as cardiac catheterisation and cardiac surgery. Early recordings with monophasic action potentials provided valuable information including normal values for the in vivo human heart, cycle length dependent properties, the effect of ischaemia, autonomic nervous system activity, and mechano-electric interaction. Transmural recordings addressed the controversial issue of the mid myocardial “M” cell. More recently, the technique of multielectrode mapping (256 electrodes) developed in animal models has been extended to humans, enabling mapping of activation and repolarisation on the entire left and right ventricular epicardium in patients during cardiac surgery. Studies have examined the issue of whether ventricular fibrillation was driven by a “mother” rotor with inhomogeneous and fragmented conduction as in some animal models, or by multiple wavelets as in other animal studies; results showed that both mechanisms are operative in humans. The simpler spatial organisation of human VF has important implications for treatment and prevention. To link in-vivo human electrophysiological mapping with cellular biophysics, multielectrode mapping is now being combined with myocardial biopsies. This technique enables region-specific electrophysiology changes to be related to underlying cellular biology, for example: APD alternans, which is a precursor of VF and sudden death. The mechanism is incompletely understood but related to calcium cycling and APD restitution. Multielectrode sock mapping during incremental pacing enables epicardial sites to be identified which exhibit marked APD alternans and sites where APD alternans is absent. Whole heart electrophysiology is assessed by activation repolarisation mapping and analysis is performed immediately on-site in order to guide biopsies to specific myocardial sites. Samples are analysed for ion channel expression, Ca2+-handling proteins, gap junctions and extracellular matrix. This new comprehensive approach to bridge cellular and whole heart electrophysiology allowed to identify 20 significant changes in mRNA for ion channels Ca2+-handling proteins, a gap junction channel, a Na+–K+ pump subunit and receptors (particularly Kir 2.1) between the positive and negative alternans sites

Solar Hydrogen Burning and Neutrinos

We summarize the current status of laboratory measurements of nuclear cross sections of the pp chain and CN cycle. We discuss the connections between such measurements, predictions of solar neutrino fluxes, and the conclusion that solar neutrinos oscillate before reaching earth.Comment: 34 pages, 6 figure

Blueprints for rural economy: Philip Lowe's work in rural and environmental social science

Philip Lowe died in February 2020, and so an academic career spanning five decades in environmental and rural social science and the sociology of knowledge came to an end. A pioneer of the social science of environmentalism since the early 1990s, Philip Lowe had been closely associated with the Centre for Rural Economy at Newcastle University in the UK and had been the intellectual force behind establishing rural economy as both a subject and mode of social science analysis. This article reflects on a career and the evolving concept of ‘rural economy’ as an economic form, a policy realm and a knowledge practice. Through this history, it presents an account of the contribution of Philip Lowe's research and writing that, as a result of his death, now stands as a bounded and complete body of work for the benefit of future generations of scholars

Effects of rare kidney diseases on kidney failure: a longitudinal analysis of the UK National Registry of Rare Kidney Diseases (RaDaR) cohort

Background Individuals with rare kidney diseases account for 5–10% of people with chronic kidney disease, but constitute more than 25% of patients receiving kidney replacement therapy. The National Registry of Rare Kidney Diseases (RaDaR) gathers longitudinal data from patients with these conditions, which we used to study disease progression and outcomes of death and kidney failure. Methods People aged 0–96 years living with 28 types of rare kidney diseases were recruited from 108 UK renal care facilities. The primary outcomes were cumulative incidence of mortality and kidney failure in individuals with rare kidney diseases, which were calculated and compared with that of unselected patients with chronic kidney disease. Cumulative incidence and Kaplan–Meier survival estimates were calculated for the following outcomes: median age at kidney failure; median age at death; time from start of dialysis to death; and time from diagnosis to estimated glomerular filtration rate (eGFR) thresholds, allowing calculation of time from last eGFR of 75 mL/min per 1·73 m2 or more to first eGFR of less than 30 mL/min per 1·73 m2 (the therapeutic trial window). Findings Between Jan 18, 2010, and July 25, 2022, 27 285 participants were recruited to RaDaR. Median follow-up time from diagnosis was 9·6 years (IQR 5·9–16·7). RaDaR participants had significantly higher 5-year cumulative incidence of kidney failure than 2·81 million UK patients with all-cause chronic kidney disease (28% vs 1%; p<0·0001), but better survival rates (standardised mortality ratio 0·42 [95% CI 0·32–0·52]; p<0·0001). Median age at kidney failure, median age at death, time from start of dialysis to death, time from diagnosis to eGFR thresholds, and therapeutic trial window all varied substantially between rare diseases. Interpretation Patients with rare kidney diseases differ from the general population of individuals with chronic kidney disease: they have higher 5-year rates of kidney failure but higher survival than other patients with chronic kidney disease stages 3–5, and so are over-represented in the cohort of patients requiring kidney replacement therapy. Addressing unmet therapeutic need for patients with rare kidney diseases could have a large beneficial effect on long-term kidney replacement therapy demand. Funding RaDaR is funded by the Medical Research Council, Kidney Research UK, Kidney Care UK, and the Polycystic Kidney Disease Charity

Harsh habitats? Waterfalls and their faunal dynamics in tropical Australia

There are few studies of the ecology of waterfalls despite their being prominent landscape features and of ecological interest because of their physical characteristics. We compared invertebrate assemblages of 5 waterfalls in the Australian Wet Tropics over 12–18 mo. Waterfall assemblages were distinct from those of riffles and bedrock, with some taxa particularly abundant on waterfalls (e.g. Simuliidae, Hydropsychidae) and others restricted to them (e.g. Blephariceridae, Pyralidae), and supported more species than bedrock but fewer than riffles. Differences among waterfalls related to differences in discharge, shade and habitat complexity. Waterfalls comprised a complex of microhabitat patches, with high-flow smooth, high-flow rough, vertical and spray zones most prevalent and distinguishable by gradient, roughness, water velocity, depth and invertebrate assemblages. In high-flow microhabitats rheophilic taxa (e.g. Simuliidae) were prevalent, while in the spray zone a range of madicolous taxa (e.g. various Coleoptera) occurred. Within microhabitats, temporal change was moderate, with stable composition over 12 months. Flood disturbance had limited effect on assemblages, as large flows overshot steep surfaces; drought may be more of a threat because recovery is hindered by isolation and lack of hyporheic refugia. Given their isolation, limited extent and distinctive fauna, waterfalls merit special conservation attentions

Instream effects of dunder application to canefields in the Sarina region, Queensland: continued monitoring

[Extract]This report summarises the results of a six year ecological monitoring program in streams of the Sarina/Mackay region. The primary focus has been placed on the final four years of investigation since the results from the first two years were discussed in detail in our earlier report (Clayton and Pearson1992). The sampling regime and the amount of resultant data were much less extensive in the final four years than in the first two years because of an altered objective to concentrate on a small number of morphologically similar streams at the time of dunder distribution.\ud \ud The background to this investigation has changed little since our first report (Clayton and Pearson 1992), although the amount of dunder sold by CSR Ltd. and the geographic extent of the dunder distribution area have both increased. In this report, therefore, introductory segments and general discussions regularly refer to the earlier report or include excerpts from it. This document can be considered the concluding volume of the investigation report and Clayton and Pearson (1992) should be referred to for detailed project background, site details and sampling/analysis methodology.\ud \ud Much of the report is necessarily technical in nature; however, where possible we have attempted to write for the non-biologist, non-chemist and non-statistician. Data used for the analyses includes that collected in the first two years of the investigation for Plane Creek, Rock Creek, Bell Creek and Marion Creek.\ud \ud The project was possible as a result of funding from CSR Ltd. and we wish to thank the staff of the Plane Creek mill and distillery for their support and assistance. We also thank the following staff from the Australian Centre for Tropical Freshwater Research who made significant contributions to the project: Jenny Holt, Niall Connolly, Michelle Reilly and staff of the ACTFR water analysis laboratory, including Barry Butler, John Faithful and Elizabeth O’Sullivan

Instream effects of dunder application to canefields in the Sarina region, Queensland: continued monitoring

[Extract]This report summarises the results of a six year ecological monitoring program in streams of the Sarina/Mackay region. The primary focus has been placed on the final four years of investigation since the results from the first two years were discussed in detail in our earlier report (Clayton and Pearson1992). The sampling regime and the amount of resultant data were much less extensive in the final four years than in the first two years because of an altered objective to concentrate on a small number of morphologically similar streams at the time of dunder distribution. The background to this investigation has changed little since our first report (Clayton and Pearson 1992), although the amount of dunder sold by CSR Ltd. and the geographic extent of the dunder distribution area have both increased. In this report, therefore, introductory segments and general discussions regularly refer to the earlier report or include excerpts from it. This document can be considered the concluding volume of the investigation report and Clayton and Pearson (1992) should be referred to for detailed project background, site details and sampling/analysis methodology. Much of the report is necessarily technical in nature; however, where possible we have attempted to write for the non-biologist, non-chemist and non-statistician. Data used for the analyses includes that collected in the first two years of the investigation for Plane Creek, Rock Creek, Bell Creek and Marion Creek. The project was possible as a result of funding from CSR Ltd. and we wish to thank the staff of the Plane Creek mill and distillery for their support and assistance. We also thank the following staff from the Australian Centre for Tropical Freshwater Research who made significant contributions to the project: Jenny Holt, Niall Connolly, Michelle Reilly and staff of the ACTFR water analysis laboratory, including Barry Butler, John Faithful and Elizabeth O’Sullivan

Insights into the labelling effect of KDPI reporting: the Australian experience

First published: 12 October 2019In 2016 Australia began reporting the Kidney Donor Performance Index (KDPI) with all deceased donor kidney transplant offers despite this not being used in organ allocation rules, offering a unique opportunity to explore the 'labelling effect' of KDPI reporting. We reviewed all kidneys retrieved for transplantation in Australia from 2015-2018 and analysed the association of KDPI reporting with organ non-utilisation, number of offer declines and donor/recipient age and longevity matching. Analyses were stratified by organ failure risk: higher risk (KDPI>80%), standard risk (KDPI 20-79%) and lower risk (KDPI 0-20%). There was no significant difference in organ non-utilisation post KDPI reporting either overall or for higher risk kidneys. KDPI reporting was associated with an increase in offer declines for both higher risk (IRR 1.45, p=0.007) and standard risk (IRR 1.22, p=0.021) kidneys, but not for lower risk organs. There was a significant increase in recipient age and Expected Post-Transplant Survival score for higher risk kidneys but no differences amongst other groups. We conclude that whilst KDPI reporting in Australia has been associated with an increased number of offer declines for higher risk kidneys, this has not resulted in increased non-utilisation and may have contributed to more appropriate use of these organs.Matthew P. Sypek, Peter Hughes, Rhonda Holdsworth, John Kanellis, Stephen McDonald, Philip D. Clayto