Pre- and postsynaptic actions of ATP on neurotransmission in rat submandibular ganglia

The pre- and postsynaptic actions of exogenously applied ATP were investigated in intact and dissociated parasympathetic neurotics of rat submandibular ganglia. Nerve-evoked excitatory postsynaptic potentials (EPSPs) were not inhibited by the purinergic receptor antagonists, suramin and pyridoxal-phosphate-6-azophenyl-2 ' ,4 ' -disulphonic acid (PPADS), or the desensitising agonist, alpha,beta -methylene ATP. In contrast. EPSPs were abolished by the nicotinic acetylcholine receptor antagonists, hexamethonium and mecamylamine. Focal application of ATP (100 muM) had no effect on membrane potential of the postsynaptic neurone or on the amplitude of spontaneous EPSPs. Taken together, these results suggest the absence of functional purinergic (P2) receptors on the postganglionic neurone in situ. In contrast, focally applied ATP (100 muM) reversibly inhibited nerve-evoked EPSPs. Similarly, bath application of the non-hydrolysable analogue of ATP, ATP gammaS, reversibly depressed EPSPs amplitude, The inhibitory effects of ATP and ATP gammaS on nerve-evoked transmitter release were antagonised by bath application of either PPADS or suramin, suggesting ATP activates a presynaptic P2 purinoceptor to inhibit acetylcholine release from preganglionic nerves in the submandibular ganglia. In acutely dissociated postganglionic neurotics from rat submandibular ganglia. focal application of ATP (100 LM) evoked an inward current and subsequent excitatory response and action potential firing, which was reversibly inhibited by PPADS (10 muM). The expression of P2X purinoceptors in wholemount and dissociated submandibular ganglion neurones was examined using polyclonal antibodies raised against the extracellular domain of six P2X purinoceptor subtypes (P2X(1-6)). In intact wholemount preparations, only the P2X(5) purinoceptor subtype was found to be expressed in the submandibular ganglion neurones and no P2X immunoreactivity was detected in the nerve fibres innervating the ganglion. Surprisingly, in dissociated submandibular ganglion neurones, high levels of P2X(2) and P2X(4) purinoceptors immunoreactivity were found on the cell surface. This increase in expression of P2X(2) and P2X(4) purinoceptors in dissociated submandibular neurones could explain the increased responsiveness of the neurotics to exogenous ATP. We conclude that disruption of ganglionic transmission in vivo by either nerve damage or synaptic blockade may up-regulate P2X expression or availability and alter neuronal excitability. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved

Selection for psychosocial treatment for youth at clinical high risk for psychosis based on the North American Prodrome Longitudinal Study individualized risk calculator

Aim: Recent findings suggest that family-focused therapy (FFT) is effective for individuals at clinical high-risk for psychosis (CHR-P). As outcomes of CHR-P individuals are quite varied, certain psychosocial interventions may be differentially effective in subgroups. The present study examined change in positive symptoms for CHR-P individuals at different levels of predicted risk for conversion to psychosis who received either FFT, a brief form of family education termed enhanced care (EC) or treatment as usual. Methods: Participants were drawn from the North American Prodromal Longitudinal Study (NAPLS2). A subset of NAPLS2 participants completed a randomized study involving FFT or EC. The present study includes participants from the FFT-CHR sub-study and non-randomized NAPLS2 participants. Predicted risk of conversion was calculated using the Individualized Risk Calculator for Psychosis. Robust linear regressions evaluated whether the association between predicted risk of conversion and positive symptom change differed across intervention groups. Results: A total of 94 participants from the FFT-CHR sub-study (FFT-CHR n = 50, EC n = 44) and 401 non-randomized NAPLS2 participants were included in this study. There was a treatment group by predicted risk of conversion interaction that predicted positive symptom improvement: higher risk individuals improved more with FFT-CHR than EC or the non-randomized NAPLS group, whereas lower-risk individuals did not differ in positive symptom improvement across treatment groups (FFT-CHR vs EC: P =.03, β = 20.27; FFT-CHR vs NAPLS2: P <.001, β = 28.40). Conclusions: Intensive treatments such as FFT-CHR may be most appropriate for individuals at the highest levels of clinical risk for psychosis

Online fluorescence spectroscopy for the real-time evaluation of the microbial quality of drinking water

We assessed the utility of online fluorescence spectroscopy for the real-time evaluation of the microbial quality of untreated drinking water. Online fluorimeters were installed on the raw water intake at four groundwater -derived UK public water supplies alongside existing turbidity sensors that are used to forewarn of the presence of microbial contamination in the water industry. The fluorimeters targeted fluorescent dissolved organic matter (DOM) peaks at excitation/emission wavelengths of 280/365 nm (tryptophan-like fluorescence, TLF) and 280/450 nm (humic-like fluorescence, HLF). Discrete samples were collected for Escherichia coli, total bacterial cell counts by flow cytometry, and laboratory-based fluorescence and absorbance. Both TLF and HLF were strongly correlated with E. coli (r ¼ 0.71e0.77)and total bacterial cell concentrations (r ¼ 0.73e0.76), whereas the correlations between turbidity and E. coli (r ¼ 0.48) and total bacterial cell counts (r ¼ 0.40) were much weaker. No clear TLF peak was observed at the sites and all apparent TLF was considered to be optical bleed-through from the neighbouring HLF peak. Therefore, a HLF fluorimeter alone would be sufficient to evaluate the microbial water quality at these sources. Fluorescent DOM was also influenced by site operations such as pump start-up and the precipitation of cations on the sensor windows. Online fluorescent DOM sensors are a better indicator of the microbial quality of untreated drinking water than turbidity and they have wide-ranging potential applications within the water industry

LivestockPlus: The sustainable intensification of forage-based agricultural systems to improve livelihoods and ecosystem services in the tropics

As global demand for livestock products (such as meat, milk, and eggs) is expected to double by 2050, necessary increases to future production must be reconciled with negative environmental impacts that livestock cause. This paper describes the LivestockPlus concept and demonstrates how the sowing of improved forages can lead to the sustainable intensification of mixed crop–forage–livestock–tree systems in the tropics by producing multiple social, economic, and environmental benefits. Sustainable intensification not only improves the productivity of tropical forage-based systems but also reduces the ecological footprint of livestock production and generates a diversity of ecosystem services (ES), such as improved soil quality and reduced erosion, sedimentation, and greenhouse gas (GHG) emissions. Integrating improved grass and legume forages into mixed production systems (crop–livestock, tree–livestock, crop–tree–livestock) can restore degraded lands and enhance system resilience to drought and waterlogging associated with climate change. When properly managed tropical forages accumulate large amounts of carbon in soil, fix atmospheric nitrogen (legumes), inhibit nitrification in soil and reduce nitrous oxide emissions (grasses), and reduce GHG emissions per unit livestock product. The LivestockPlus concept is defined as the sustainable intensification of forage-based systems, which is based on three interrelated intensification processes: genetic intensification – the development and use of superior grass and legume cultivars for increased livestock productivity; ecological intensification – the development and application of improved farm and natural resource management practices; and socio-economic intensification – the improvement of local and national institutions and policies, which enable refinements of technologies and support their enduring use. Increases in livestock productivity will require coordinated efforts to develop supportive government, non-government organization, and private sector policies that foster investments and fair market compensation for both the products and ES provided. Effective research-for-development efforts that promote agricultural and environmental benefits of forage-based systems can contribute towards implemention of LivestockPlus across a variety of geographic, political, and socio-economic contexts

A global horizon scan of issues impacting marine and coastal biodiversity conservation

The biodiversity of marine and coastal habitats is experiencing unprecedented change. While there are well-known drivers of these changes, such as overexploitation, climate change and pollution, there are also relatively unknown emerging issues that are poorly understood or recognized that have potentially positive or negative impacts on marine and coastal ecosystems. In this inaugural Marine and Coastal Horizon Scan, we brought together 30 scientists, policymakers and practitioners with transdisciplinary expertise in marine and coastal systems to identify new issues that are likely to have a significant impact on the functioning and conservation of marine and coastal biodiversity over the next 5–10 years. Based on a modified Delphi voting process, the final 15 issues presented were distilled from a list of 75 submitted by participants at the start of the process. These issues are grouped into three categories: ecosystem impacts, for example the impact of wildfires and the effect of poleward migration on equatorial biodiversity; resource exploitation, including an increase in the trade of fish swim bladders and increased exploitation of marine collagens; and new technologies, such as soft robotics and new biodegradable products. Our early identification of these issues and their potential impacts on marine and coastal biodiversity will support scientists, conservationists, resource managers and policymakers to address the challenges facing marine ecosystems

Guidelines for the management of pregnancy in women with cystic fibrosis

Women with cystic fibrosis (CF) now regularly survive into their reproductive years in good health and wish to have a baby. Many pregnancies have been reported in the literature and it is clear that whilst the outcome for the baby is generally good and some mothers do very well, others find either their CF complicates the pregnancy or is adversely affected by the pregnancy. For some, pregnancy may only become possible after transplantation. Optimal treatment of all aspects of CF needs to be maintained from the preconceptual period until after the baby is born. Clinicians must be prepared to modify their treatment to accommodate the changing physiology during pregnancy and to be aware of changing prescribing before conception, during pregnancy, after birth and during breast feeding. This supplement offers consensus guidelines based on review of the literature and experience of paediatricians, adult and transplant physicians, and nurses, physiotherapists, dietitians, pharmacists and psychologists experienced in CF and anaesthetist and obstetricians with experience of CF pregnancy. It is hoped they will provide practical guidelines helpful to the multidisciplinary CF teams caring for pregnant women with CF

Models for queueing systems with 'feedback'

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