Denitrification bioreactor trial in the Russell River catchment of the Wet Tropics: final report

Dissolved inorganic nitrogen (DIN) in runoff from agricultural land is considered to have a significant detrimental impact on the Great Barrier Reef (GBR). Losses of DIN to runoff can be reduced by good agricultural practices, but they cannot be eliminated entirely in the Wet Tropics due to the need for adequate nitrogen supply to crops, the high solubility of DIN, particularly nitrate, and high rainfall. Thus, it is inevitable that DIN concentrations are higher in runoff from agricultural land than from forested areas. Some of this DIN is removed from the water as it moves through aquifers, creeks, rivers, and wetlands on its way to the sea, through the process of microbial denitrification. Denitrification involves the conversion of nitrate and nitrite (NOx-N) to dinitrogen (N2) gas, which is lost to the atmosphere. Denitrification requires NOx-N, organic matter, and low oxygen concentration. Wetlands provide these conditions, so DIN concentrations decline in water moving through them. Similarly, denitrifying bioreactors are designed to treat water by passing it through a porous organic material, typically woodchips. The woodchips provide organic matter for the microorganisms, which in turn lower the oxygen concentration, providing ideal conditions for denitrification. Denitrifying bioreactors are now widely used to remove the NOx-N component of DIN from agricultural runoff water elsewhere, but they have not yet been evaluated in the Wet Tropics. The Wet Tropics pose a challenge for efficacy due to the large volumes of water moving through the landscape. The objective of this project was “to establish the effectiveness of denitrifying bioreactors as a remediation technology for excess DIN in agricultural runoff within the Babinda Swamp Drainage Area (BSDA) of the Russell catchment”. The Russell River exports a disproportionate amount of DIN to the GBR lagoon because of the high rainfall and high proportion of agriculture, mostly sugarcane, in its catchment

All clinically-relevant blood components transmit prion disease following a single blood transfusion: a sheep model of vCJD

Variant CJD (vCJD) is an incurable, infectious human disease, likely arising from the consumption of BSE-contaminated meat products. Whilst the epidemic appears to be waning, there is much concern that vCJD infection may be perpetuated in humans by the transfusion of contaminated blood products. Since 2004, several cases of transfusion-associated vCJD transmission have been reported and linked to blood collected from pre-clinically affected donors. Using an animal model in which the disease manifested resembles that of humans affected with vCJD, we examined which blood components used in human medicine are likely to pose the greatest risk of transmitting vCJD via transfusion. We collected two full units of blood from BSE-infected donor animals during the pre-clinical phase of infection. Using methods employed by transfusion services we prepared red cell concentrates, plasma and platelets units (including leucoreduced equivalents). Following transfusion, we showed that all components contain sufficient levels of infectivity to cause disease following only a single transfusion and also that leucoreduction did not prevent disease transmission. These data suggest that all blood components are vectors for prion disease transmission, and highlight the importance of multiple control measures to minimise the risk of human to human transmission of vCJD by blood transfusion

Endothelin-1 Predicts Hemodynamically Assessed Pulmonary Arterial Hypertension in HIV Infection.

BackgroundHIV infection is an independent risk factor for PAH, but the underlying pathogenesis remains unclear. ET-1 is a robust vasoconstrictor and key mediator of pulmonary vascular homeostasis. Higher levels of ET-1 predict disease severity and mortality in other forms of PAH, and endothelin receptor antagonists are central to treatment, including in HIV-associated PAH. The direct relationship between ET-1 and PAH in HIV-infected individuals is not well described.MethodsWe measured ET-1 and estimated pulmonary artery systolic pressure (PASP) with transthoracic echocardiography (TTE) in 106 HIV-infected individuals. Participants with a PASP ≥ 30 mmHg (n = 65) underwent right heart catheterization (RHC) to definitively diagnose PAH. We conducted multivariable analysis to identify factors associated with PAH.ResultsAmong 106 HIV-infected participants, 80% were male, the median age was 52 years and 77% were on antiretroviral therapy. ET-1 was significantly associated with higher values of PASP [14% per 0.1 pg/mL increase in ET-1, p = 0.05] and PASP ≥ 30 mmHg [PR (prevalence ratio) = 1.24, p = 0.012] on TTE after multivariable adjustment for PAH risk factors. Similarly, among the 65 individuals who underwent RHC, ET-1 was significantly associated with higher values of mean pulmonary artery pressure and PAH (34%, p = 0.003 and PR = 2.43, p = 0.032, respectively) in the multivariable analyses.ConclusionsHigher levels of ET-1 are independently associated with HIV-associated PAH as hemodynamically assessed by RHC. Our findings suggest that excessive ET-1 production in the setting of HIV infection impairs pulmonary endothelial function and contributes to the development of PAH

Complex Calculations: How Drug Use During Pregnancy Becomes a Barrier to Prenatal Care

Pregnant women who use drugs are more likely to receive little or no prenatal care. This study sought to understand how drug use and factors associated with drug use influence women’s prenatal care use. A total of 20 semi-structured interviews and 2 focus groups were conducted with a racially/ethnically diverse sample of low-income women using alcohol and drugs in a California county. Women using drugs attend and avoid prenatal care for reasons not connected to their drug use: concern for the health of their baby, social support, and extrinsic barriers such as health insurance and transportation. Drug use itself is a barrier for a few women. In addition to drug use, women experience multiple simultaneous risk factors. Both the drug use and the multiple simultaneous risk factors make resolving extrinsic barriers more difficult. Women also fear the effects of drug use on their baby’s health and fear being reported to Child Protective Services, each of which influence women’s prenatal care use. Increasing the number of pregnant women who use drugs who receive prenatal care requires systems-level rather than only individual-level changes. These changes require a paradigm shift to viewing drug use in context of the person and society and acceptance of responsibility for unintended consequences of public health bureaucratic procedures and messages about effects of drug use during pregnancy

Geological archive of the onset of plate tectonics

© 2018 The Author(s) Published by the Royal Society. All rights reserved. Plate tectonics, involving a globally linked system of lateral motion of rigid surface plates, is a characteristic feature of our planet, but estimates of how long it has been the modus operandi of lithospheric formation and interactions range from the Hadean to the Neoproterozoic. In this paper, we review sedimentary, igneous and metamorphic proxies along with palaeomagnetic data to infer both the development of rigid lithospheric plates and their independent relative motion, and conclude that significant changes in Earth behaviour occurred in the mid- to late Archaean, between 3.2 Ga and 2.5 Ga. These data include: sedimentary rock associations inferred to have accumulated in passive continental margin settings, marking the onset of seafloor spreading; the oldest foreland basin deposits associated with lithospheric convergence; a change from thin, new continental crust of mafic composition to thicker crust of intermediate composition, increased crustal reworking and the emplacement of potassic and peraluminous granites, indicating stabilization of the lithosphere; replacement of dome and keel structures in granite-greenstone terranes, which relate to vertical tectonics, by linear thrust imbricated belts; the commencement of temporally paired systems of intermediate and high dT/dP gradients, with the former interpreted to represent subduction to collisional settings and the latter representing possible hinterland back-arc settings or ocean plateau environments. Palaeomagnetic data from the Kaapvaal and Pilbara cratons for the interval 2780-2710Ma and from the Superior, Kaapvaal and Kola-Karelia cratons for 2700-2440Ma suggest significant relative movements. We consider these changes in the behaviour and character of the lithosphere to be consistent with a gestational transition from a non-plate tectonic mode, arguably with localized subduction, to the onset of sustained plate tectonics

Shear Capacity of Monolithic Concrete Joints without Transverse Reinforcement.

yesA mechanism analysis based on the upper-bound theorem of concrete plasticity for monolithic concrete joints without transverse reinforcement is presented. Concrete is modelled as a rigid–perfectly plastic material obeying modified Coulomb failure criteria. Existing stress–strain relationships of concrete in compression and tension are comprehensively modified using the crack band theory to allow for concrete type and maximum aggregate size. Simple equations for the effectiveness factor for compression, ratio of effective tensile strength to compressive strength and angle of concrete friction are then mathematically developed using the modified stress–strain relationships of concrete. In addition, 12 push-off specimens made of all-lightweight, sand–lightweight and normal-weight concrete having maximum aggregate size between 4 and 19 mm were physically tested. Test results and mechanism analysis clearly showed that the shear capacity of monolithic concrete joints increased with the increase of the maximum aggregate size and dry density of concrete. The mean and standard deviation of the ratio between experimentally measured and predicted (by the mechanism analysis shear capacities) are 1·01 and 0·16 respectively, showing a closer prediction and less variation than Vecchio and Collins' equation, regardless of concrete type and maximum aggregate size

Optimization of Naked DNA Delivery for Interferon Subtype Immunotherapy in Cytomegalovirus Infection

Type I interferon (IFN) gene therapy modulates the immune response leading to inflammatory heart disease following cytomegalovirus (CMV) infection in a murine model of post-viral myocarditis. Efficacy of different immunisation protocols for the IFN constructs was influenced by the dose of DNA, subtype choice, combination use, pre-medication, and timing of DNA administration. Optimal efficacy was found with bupivacaine treatment prior to DNA inoculation of 200mg IFN DNA 14 days prior to virus challenge. Maximal antiviral and antimyocarditic effects were achieved with this vaccination schedule. Furthermore, inoculation of synergistic IFN subtypes demonstrated enhanced efficacy when delivered either alone or with CMV gB DNA vaccination in the CMV model. Thus naked DNA delivery of IFN provides an avenue of immunotherapy for regulating herpesvirus-induced diseases

Relating reflex gain modulation in posture control to underlying neural network properties using a neuromusculoskeletal model

During posture control, reflexive feedback allows humans to efficiently compensate for unpredictable mechanical disturbances. Although reflexes are involuntary, humans can adapt their reflexive settings to the characteristics of the disturbances. Reflex modulation is commonly studied by determining reflex gains: a set of parameters that quantify the contributions of Ia, Ib and II afferents to mechanical joint behavior. Many mechanisms, like presynaptic inhibition and fusimotor drive, can account for reflex gain modulations. The goal of this study was to investigate the effects of underlying neural and sensory mechanisms on mechanical joint behavior. A neuromusculoskeletal model was built, in which a pair of muscles actuated a limb, while being controlled by a model of 2,298 spiking neurons in six pairs of spinal populations. Identical to experiments, the endpoint of the limb was disturbed with force perturbations. System identification was used to quantify the control behavior with reflex gains. A sensitivity analysis was then performed on the neuromusculoskeletal model, determining the influence of the neural, sensory and synaptic parameters on the joint dynamics. The results showed that the lumped reflex gains positively correlate to their most direct neural substrates: the velocity gain with Ia afferent velocity feedback, the positional gain with muscle stretch over II afferents and the force feedback gain with Ib afferent feedback. However, position feedback and force feedback gains show strong interactions with other neural and sensory properties. These results give important insights in the effects of neural properties on joint dynamics and in the identifiability of reflex gains in experiments

Choosing to live with home dialysis-patients' experiences and potential for telemedicine support: a qualitative study

<p>Abstract</p> <p>Background</p> <p>This study examines the patients' need for information and guidance in the selection of dialysis modality, and in establishing and practicing home dialysis. The study focuses on patients' experiences living with home dialysis, how they master the treatment, and their views on how to optimize communication with health services and the potential of telemedicine.</p> <p>Methods</p> <p>We used an inductive research strategy and conducted semi-structured interviews with eleven patients established in home dialysis. Our focus was the patients' experiences with home dialysis, and our theoretical reference was patients' empowerment through telemedicine solutions. Three informants had home haemodialysis (HHD); eight had peritoneal dialysis (PD), of which three had automated peritoneal dialysis (APD); and five had continuous ambulatory peritoneal dialysis (CAPD). The material comprises all PD-patients in the catchment area capable of being interviewed, and all known HHD-users in Norway at that time.</p> <p>Results</p> <p>All of the interviewees were satisfied with their choice of home dialysis, and many experienced a normalization of daily life, less dominated by disease. They exhibited considerable self-management skills and did not perceive themselves as ill, but still required very close contact with the hospital staff for communication and follow-up. When choosing a dialysis modality, other patients' experiences were often more influential than advice from specialists. Information concerning the possibility of having HHD, including knowledge of how to access it, was not easily available. Especially those with dialysis machines, both APD and HHD, saw a potential for telemedicine solutions.</p> <p>Conclusions</p> <p>As home dialysis may contribute to a normalization of life less dominated by disease, the treatment should be organized so that the potential for home dialysis can be fully exploited. Pre-dialysis information should be unbiased and include access to other patients' experiences. Telemedicine may potentially facilitate a communication-based follow-up and improve safety within the home setting, making it easier to choose and live with home dialysis.</p