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Many freshwater crayfish are threatened with extinction owing to varied threats such as urban development, pollution, over‐harvest, and climate change, as well as invasive species.A recently published manuscript in Aquatic Conservation: Marine and Freshwater Ecosystems described a stochastic, age‐based population model for the large freshwater crayfish Murray crayfish, Euastacus armatus, which is now threatened across much of its range in the Murray–Darling Basin in south‐eastern Australia.The model was constructed for three regional populations using the best available knowledge of life‐history traits such as longevity, size at onset of sexual maturity, fecundity, and survival, along with an account of density dependence. The model provides a framework to explore aspects of the conservation and management of the species, including assessing the influence of recreational harvest and environmental disturbance such as hypoxic blackwater, which affected the species significantly in 2010–2011.The application of the model provided retrospective justification for regulation amendments and highlighted biologically realistic timeframes for the recovery of impaired populations. This knowledge has assisted multi‐jurisdictional fisheries management agencies to undertake routine reviews of fishery regulations, as well as to inform stakeholders of the benefits of the regulation amendments.Refinement of the modelling framework has already provided additional insight and it is anticipated that future application will help to address other important management questions. The modelling outcomes are at present informing conservation assessment of the species under the Australian Government's Environmental Protection and Biodiversity Conservation Act 1999.The benefit of the population model can be summarized as: providing a framework to inform and justify management decisions; enabling additional research; and guiding conservation assessment. This has strengthened strong partnerships (between ecologists, managers, and recreational fishers) required to manage the species effectively. [ABSTRACT FROM AUTHOR]

The history of the Greenland Ice Sheet has been influenced by the geodynamic response to ice sheet fluctuations, and this interaction may help explain past deglaciations under modest climate forcing. We hypothesize that when the Iceland hot spot passed beneath north‐central Greenland, it thinned the lithosphere and left anomalous heat likely with partially melted rock; however, it did not break through the crust to supply voluminous flood basalts. Subsequent Plio‐Pleistocene glacial‐interglacial cycles caused large and rapidly migrating stresses, driving dike formation and other processes that shifted melted rock toward the surface. The resulting increase in surface geothermal flux favored a thinner, faster‐responding ice sheet that was more prone to deglaciation. If this hypothesis of control through changes in geothermal flux is correct, then the long‐term (105 to 106 years) trend now is toward lower geothermal flux, but with higher‐frequency (≤104 to 105 years) oscillations linked to glacial‐interglacial cycles. Whether the geothermal flux is increasing or decreasing now is not known but is of societal relevance due to its possible impact on ice flow. We infer that projections of the future of the ice sheet and its effect on sea level must integrate geologic and geophysical data as well as glaciological, atmospheric, oceanic, and paleoclimatic information. Plain Language Summary: The behavior of the Greenland Ice Sheet and its effect on future sea level depends on its geologic history as well as on greenhouse warming. The Iceland hot spot passed beneath Greenland millions of years ago, and left hot, possibly melted rock deep beneath the island. Since then, growth and shrinkage of the ice sheet have changed stresses in the rocks beneath. These stress changes may have shifted the melted rock upward, perhaps all the way to the base of the ice sheet, probably in pulses tied to times of rapid ice sheet change. This would have changed the heat flow from the Earth into the base of the ice, which affects how easily the ice sheet grows and shrinks. The future of the ice sheet depends primarily on how much the climate warms, but better understanding of the interactions between the ice and the rocks beneath will allow better predictions of ice sheet changes. Key Points: Ice sheet fluctuations affect the lithosphere and asthenosphereGreenland Ice Sheet fluctuations may have extracted melt from the track of the Iceland hot spotResulting changes in geothermal flux may help explain past and ongoing ice sheet evolution [ABSTRACT FROM AUTHOR]

Abstract: Numerous freshwater species are recreationally harvested, yet conservation concerns are often ignored. This may lead to conflict between fisheries and conservation management for a species. Approximately one‐third of freshwater crayfish species globally are threatened with extinction, including the Murray crayfish, Euastacus armatus (von Martens, 1866) in south‐eastern Australia. There has been substantial commercial and recreational fishing of E. armatus since European settlement, as well as other threats such as poor water quality (e.g. hypoxic ‘blackwater events’ during floods). A stochastic population model was developed for three regional populations of male and female E. armatus, and was used to examine the effects of fishing and hypoxic blackwater disturbance on a Murray crayfish population in a lowland region. The results indicate that the Murray crayfish population in the lowland region faces increasing risks from increasing fishing pressure, together with low frequencies of hypoxic blackwater disturbance only. Testing various fishery regulations, the modelling demonstrated that recent changes to the ‘slot size’ in occipital carapace length of 10–12 cm for legally harvesting crayfish was a suitable protection measure given the background levels of hypoxic blackwater disturbance, balancing fishing and conservation concerns. Although higher slots (11–13 cm and 12–14 cm) were less sensitive to higher fishing pressures, the recreational harvest declined. The model was most sensitive to early life‐history survival rates; however, sensitivity analysis of model variability also indicated that E. armatus may be susceptible to highly variable environments (not to be confused with highly variable flows). This study demonstrates the successful integration of fishing and conservation in a flexible risk framework for this threatened freshwater crayfish species; furthermore, fisher expectation can be managed by assessing the impact on harvest of potential changes to fishing regulations. This approach is easily transferable and would improve the management of other recreationally fished species facing multiple threats. [ABSTRACT FROM AUTHOR]

Introduction: The ~31-km-wide Hiawatha structure, located beneath Hiawatha Glacier in northwestern Greenland, has been proposed as an impact structure that may have formed after the Pleistocene inception of the Greenland Ice Sheet [1]. However, available age constraints for the Hiawatha structure have only been tentative. The bedrock under the structure is likely a continuation of the highly metamorphosed 1.95-1.75 Ga [2] bedrock exposed immediately adjacent to Hiawatha Glacier, providing a maximum constraint on the structure's age [1]. Further age estimates have been based on indirect constraints, such as estimates of erosion rates and the structure's relationship to the Greenland Ice Sheet [1]. Here we dated the structure using detrital materials sampled immediately downstream thereof. We report 40Ar/39Ar analyses of impact-related glaciofluvial sand collected in 2016 and U-Pb analyses of shocked zircon from pebble-sized glaciofluvial clasts of impact melt rock collected in 2019. Results: Of the 50 grains that underwent 40Ar/39Ar step-heating analysis, 29 developed 'U'- or 'saddle'-shaped age spectra, with 23 giving minimum apparent ages in the Paleocene. Two mini-plateaus gave Late Paleocene ages of 58.5 ± 0.3 Ma and 60.2 ± 0.5 Ma, respectively. The 62 U-Pb analysis performed on 43 zircon grains using secondary ion mass spectrometry (SIMS) defined a discordant array in concordia space, spreading between an upper intercept of ~1915 Ma and a Late Paleocene lower intercept. The ~1915 Ma age for the majority of unshocked zircon grains from the impact melt rocks agrees with known geological events and zircon ages from the bedrock adjacent to Hiawatha Glacier [2], supporting a local origin for the samples. Of the 45 analyses performed on shocked zircon grains, the youngest nine data points are statistically indistinguishable, giving a robust concordia age and a weighted mean 206Pb/238U age of 57.99 ± 0.54 Ma (MSWD = 1.18; probability = 0.30; n = 9). We consider this to be the most robust estimate for the age of the impact structure [3]. Discussion: Impact melt rocks collected less than 10 km downstream from the edge of the Hiawatha structure contain unshocked zircon with ages matching that of the bedrock adjacent to Hiawatha Glacier. Shocked zircon in these samples gives a ~58 Ma U-Pb age, which agrees with the younger of two 40Ar/39Ar mini-plateau ages from the sand sample. The samples were thus derived from a Late Paleocene impact structure somewhere upstream but sufficiently proximal that the target geology is indistinguishable geochronologically from that exposed where the samples were recovered. Given existing geomorphic evidence for an eroded complex impact structure beneath Hiawatha Glacier, we suggest this is the source of the samples and thus that the Hiawatha structure is a relatively large impact structure that formed in the Late Paleocene. The new age indicates that the Hiawatha impact structure significantly predates Pleistocene glaciation and is unrelated to either the Paleocene-Eocene Thermal Maximum or flood basalt volcanism in east Greenland. The impact was contemporaneous with the Paleocene Carbon Isotope Maximum, although the impact's exact paleoenvironmental and climatic significance await further investigation. [ABSTRACT FROM AUTHOR]

Background Cardiac biomarkers provide objective data that augments clinical assessment of heart disease ( HD). Hypothesis/Objectives Determine the utility of plasma N-terminal pro-brain natriuretic peptide concentration [NT-proBNP] measured by a 2nd generation canine ELISA assay to discriminate cardiac from noncardiac respiratory distress and evaluate HD severity. Animals Client-owned dogs (n = 291). Methods Multicenter, cross-sectional, prospective investigation. Medical history, physical examination, echocardiography, and thoracic radiography classified 113 asymptomatic dogs (group 1, n = 39 without HD; group 2, n = 74 with HD), and 178 with respiratory distress (group 3, n = 104 respiratory disease, either with or without concurrent HD; group 4, n = 74 with congestive heart failure [ CHF]). HD severity was graded using International Small Animal Cardiac Health Council ( ISACHC) and ACVIM Consensus ( ACVIM- HD) schemes without knowledge of [NT-proBNP] results. Receiver-operating characteristic curve analysis assessed the capacity of [NT-proBNP] to discriminate between dogs with cardiac and noncardiac respiratory distress. Multivariate general linear models containing key clinical variables tested associations between [NT-proBNP] and HD severity. Results Plasma [NT-proBNP] (median; IQR) was higher in CHF dogs (5,110; 2,769-8,466 pmol/L) compared to those with noncardiac respiratory distress (1,287; 672-2,704 pmol/L; P < .0001). A cut-off >2,447 pmol/L discriminated CHF from noncardiac respiratory distress (81.1% sensitivity; 73.1% specificity; area under curve, 0.84). A multivariate model comprising left atrial to aortic ratio, heart rate, left ventricular diameter, end-systole, and ACVIM- HD scheme most accurately associated average plasma [NT-proBNP] with HD severity. Conclusions and Clinical Importance Plasma [NT-proBNP] was useful for discriminating CHF from noncardiac respiratory distress. Average plasma [NT-BNP] increased significantly as a function of HD severity using the ACVIM- HD classification scheme. [ABSTRACT FROM AUTHOR]

Objective To investigate the distribution and prevalence of mucormycosis in platypus ( Ornithorhynchus anatinus) from the Inglis, Emu and Black-Detention catchment areas in north-west Tasmania. Procedure A field study was performed and resulted in the examination of 44 wild platypuses; in addition, one dead platypus and two live platypuses were examined after they were independently submitted to a local veterinary clinic. Results No cases of mucormycosis were conclusively diagnosed. One platypus with signs consistent with those previously described in cases of mucormycosis was captured in the Emu River catchment. However, laboratory tests did not provide a definitive diagnosis for the lesion. Two platypuses from the Inglis catchment area had signs very similar to those previously described in cases of mucormycosis, but laboratory tests found Corynebacterium ulcerans to be the likely cause of the cutaneous ulcers on one of these platypuses and an unidentified fungal agent to be the cause of a cutaneous nodule in the other. Conclusions These findings do not prove that mucormycosis is absent from the populations studied. However, they may indicate that the prevalence of disease is low. The possibility that Mucor amphibiorum is present in a subclinical form in platypuses, or infecting another reservoir, is not excluded. The findings also suggest that caution should be exercised when diagnosing mucormycosis based on clinical findings alone and raise the possibility that some cases may have been incorrectly diagnosed. [ABSTRACT FROM AUTHOR]

Change and transition are different concepts. Transition for practitioners in the workplace is complex. Transition within roles needs a positive tripartite arrangement with teacher and clinical manager. This paper looks at the findings from a study of 100 enrolled nurses undertaking a part-time conversion programme to RGN, RMN or RSCN. Evidence suggests that student perceptions change over time within a 2-year programme. This conversion programme is seen as a positive experience by participants and employers. [ABSTRACT FROM AUTHOR]

The records of Aberdeen men requesting vasectomy between 1978 and 1981 were studied and a sample of men were interviewed about 3 years after the operation; 85% completed the standard requirements for seminal analysis and were given the 'all clear'; two-thirds were cleared after sending 2 samples and usually within 20 weeks after vasectomy; 10% of men sent at least 1 sample but were never cleared and the remaining 5% ignored the requirements. Information from 70 men (63 interviews, 7 questionnaires) gave some indication of reasons, often multiple, for incomplete or non-compliance; these included embarrassment, ambiguous feelings about having more children, inadequate understanding of reproductive physiology and blind faith in the surgeon. [ABSTRACT FROM AUTHOR]

Aim: This study set out to investigate the effect of a conversion course on the careers of enrolled nurses. Background: Funding has been made available for nurses to convert from second level to first level registration. Managers need to know the value of this initiative. Method: Questionnaires sent to a sample of 130 enrolled nurses and semi-structured interviews with eight nurses and one manager. Descriptive statistics were used to analyse the questionnaires and themes identified from the transcripts of the interviews. Findings: One year after completion, participants identified changes in grade, job and further study. Interviews revealed a developmental change in their personal and professional life. The depth of perceived prejudice towards them remains very powerful. Conclusion: Converting to first level registration appears to have positive outcomes for most nurses in the study and has resulted in wider opportunities for their careers and professional development. [ABSTRACT FROM AUTHOR]

SUMMARY Powdered apatitic renal calculi have been allowed to come into equilibrium with buffers in the pH range 7 to 8., The ion products for the commoner calcium phosphate salts have been calculated and related to pH at equilibrium., Only the pK of the ion product [Ca++]8[HPO4=]2[PO4≡]6 is independent of pH, Determination of the stoichiometry of the exchange reaction at equilibrium suggests a Ca: P of 7.9:6., It is suggested that, quite apart from the apparent average composition of apatitic renal calculi, the phase on the crystal surfaces determining the physico-chemical characteristics of the equilibrium is octocalcium phosphate., It is suggested that the critical phase governing the solubility of calcium phosphate in urine in vivo may be octocalcium phosphate. [ABSTRACT FROM AUTHOR]