407 research outputs found

    Water Quality Conflict Resolution and Agricultural Discharges: Lessons from Waterkeeper v. Hudson

    Full text link
    This Article presents a comparative institutional analysis of an increasingly important type of environmental conflict—the agricultural-waste-discharge and water-land-nexus conflict—using the recent citizen suit Waterkeeper v. Hudson as a case study. The objective is to assess the resource allocation efficiency and procedural fairness of the dispute processing in Hudson. The Hudson setting involves substantial scientific complexity, including ecological interdependencies, unobservable and observable land management decisions, pollutant transport, in-stream removal, and the problem of multiple and diverse sources of water quality pollution. Although the Hudson farm does fall under a regulated point source category in a state legislative definition, not all agricultural practices on the property are regulated. Hudson and other cases are demanding clearer definition of rights allocated and duties assigned in the waterland nexus conflict

    Competing for space in an already crowded market: a mixed methods study of why an online community of practice (CoP) for alcohol harm reduction failed to generate interest amongst the group of public health professionals at which it was aimed.

    Get PDF
    BACKGROUND: Improving mechanisms for knowledge translation (KT) and connecting decision-makers to each other and the information and evidence they consider relevant to their work remains a priority for public health. Virtual communities of practices (CoPs) potentially offer an affordable and flexible means of encouraging connection and sharing of evidence, information and learning among the public health community in ways that transgress traditional geographical, professional, institutional and time boundaries. The suitability of online CoPs in public health, however, has rarely been tested. This paper explores the reasons why particular online CoP for alcohol harm reduction hosted by the UK Health Forum failed to generate sufficient interest from the group of public health professionals at which it was aimed. METHODS: The study utilises online web-metrics demonstrating a lack of online activity on the CoP. One hundred and twenty seven responses to an online questionnaire were used to explore whether the lack of activity could be explained by the target audience's existing information and evidence practices and needs. Qualitative interviews with 10 members describe in more detail the factors that shape and inhibit use of the virtual CoP by those at which it was targeted. RESULTS: Quantitative and qualitative data confirm that the target audience had an interest in the kind of information and evidence the CoP was set up to share and generate discussion about, but also that participants considered themselves to already have relatively good access to the information and evidence they needed to inform their work. Qualitative data revealed that the main barriers to using the CoP were a proliferation of information sources meaning that participants preferred to utilise trusted sources that were already established within their daily routines and a lack of time to engage with new online tools that required any significant commitment. CONCLUSIONS: Specialist online CoPs are competing for space in an already crowded market. A target audience that regards itself as busy and over-supplied is unlikely to commit to a new service without the assurance that the service will provide unique and valuable well-summarised information, which would reduce the need to spend time accessing competing resources

    The Deformable Mirror Demonstration Mission (DeMi) CubeSat: optomechanical design validation and laboratory calibration

    Full text link
    Coronagraphs on future space telescopes will require precise wavefront correction to detect Earth-like exoplanets near their host stars. High-actuator count microelectromechanical system (MEMS) deformable mirrors provide wavefront control with low size, weight, and power. The Deformable Mirror Demonstration Mission (DeMi) payload will demonstrate a 140 actuator MEMS deformable mirror (DM) with \SI{5.5}{\micro\meter} maximum stroke. We present the flight optomechanical design, lab tests of the flight wavefront sensor and wavefront reconstructor, and simulations of closed-loop control of wavefront aberrations. We also present the compact flight DM controller, capable of driving up to 192 actuator channels at 0-250V with 14-bit resolution. Two embedded Raspberry Pi 3 compute modules are used for task management and wavefront reconstruction. The spacecraft is a 6U CubeSat (30 cm x 20 cm x 10 cm) and launch is planned for 2019.Comment: 15 pages, 10 figues. Presented at SPIE Astronomical Telescopes + Instrumentation, Austin, Texas, US

    Pancreas++: Automated Quantification of Pancreatic Islet Cells in Microscopy Images

    Get PDF
    The microscopic image analysis of pancreatic Islet of Langerhans morphology is crucial for the investigation of diabetes and metabolic diseases. Besides the general size of the islet, the percentage and relative position of glucagon-containing alpha-, and insulin-containing beta-cells is also important for pathophysiological analyses, especially in rodents. Hence, the ability to identify, quantify and spatially locate peripheral, and “involuted” alpha-cells in the islet core is an important analytical goal. There is a dearth of software available for the automated and sophisticated positional quantification of multiple cell types in the islet core. Manual analytical methods for these analyses, while relatively accurate, can suffer from a slow throughput rate as well as user-based biases. Here we describe a newly developed pancreatic islet analytical software program, Pancreas++, which facilitates the fully automated, non-biased, and highly reproducible investigation of islet area and alpha- and beta-cell quantity as well as position within the islet for either single or large batches of fluorescent images. We demonstrate the utility and accuracy of Pancreas++ by comparing its performance to other pancreatic islet size and cell type (alpha, beta) quantification methods. Our Pancreas++ analysis was significantly faster than other methods, while still retaining low error rates and a high degree of result correlation with the manually generated reference standard

    Quantifying Ca 2+ Current and Permeability in ATP-gated P2X7 Receptors

    Get PDF
    International audienceATP-gated P2X7 receptors are prominently expressed in inflammatory cells and play a key role in the immune response. A major consequence of receptor activation is the regulated influx of Ca(2+) through the self-contained cation non-selective channel. Although the physiological importance of the resulting rise in intracellular Ca(2+) is universally acknowledged, the biophysics of the Ca(2+) flux responsible for the effects are poorly understood, largely because traditional methods of measuring Ca(2+) permeability are difficult to apply to P2X7 receptors. Here we use an alternative approach, called dye-overload patch-clamp photometry, to quantify the agonist-gated Ca(2+) flux of recombinant P2X7 receptors of dog, guinea pig, human, monkey, mouse, rat, and zebrafish. We find that the magnitude of the Ca(2+) component of the ATP-gated current depends on the species of origin, the splice variant, and the concentration of the purinergic agonist. We also measured a significant contribution of Ca(2+) to the agonist-gated current of the native P2X7Rs of mouse and human immune cells. Our results provide cross-species quantitative measures of the Ca(2+) current of the P2X7 receptor for the first time, and suggest that the cytoplasmic N terminus plays a meaningful role in regulating the flow of Ca(2+) through the channel

    Antiplasmodial activity, in vivo pharmacokinetics and anti-malarial efficacy evaluation of hydroxypyridinone hybrids in a mouse model

    Get PDF
    BackgroundDuring the erythrocytic stage in humans, malaria parasites digest haemoglobin of the host cell, and the toxic haem moiety crystallizes into haemozoin. Chloroquine acts by forming toxic complexes with haem molecules and interfering with their crystallization. In chloroquine-resistant strains, the drug is excluded from the site of action, which causes the parasites to accumulate less chloroquine in their acid food vacuoles than chloroquine-sensitive parasites. 3-Hydroxylpyridin-4-ones are known to chelate iron; hydroxypyridone-chloroquine (HPO-CQ) hybrids were synthesized in order to determine whether they can inhibit parasites proliferation in the parasitic digestive vacuole by withholding iron from plasmodial parasite metabolic pathway.MethodsTwo HPO-CQ hybrids were tested against Plasmodium falciparum chloroquine-sensitive (D10 and 3D7) and -resistant strains (Dd2 and K1). The pharmacokinetic properties of active compounds were determined using a mouse model and blood samples were collected at different time intervals and analysed using LC–MS/MS. For in vivo efficacy the mice were infected with Plasmodium berghei in a 4-day Peters’ test. The parasitaemia was determined from day 3 and the course of the infection was followed by microscopic examination of stained blood films every 2–3days until a rise in parasitaemia was observed in all test subjects.ResultsIC50 values of the two compounds for sensitive and resistant strains were 0.064 and 0.047µM (compound 1), 0.041 and 0.122µM (compound 2) and 0.505 and 0.463µM (compound 1), 0.089 and 0.076µM (compound 2), respectively. Pharmacokinetic evaluation of these compounds showed low oral bioavailability and this affected in vivo efficacy when compounds were dosed orally. However, when dosed intravenously compound 1 showed a clearance rate of 28ml/min/kg, an apparent volume of distribution of 20l/kg and a half-life of 4.3h. A reduction in parasitaemia was observed when compound 1 was dosed intravenously for four consecutive days in P. berghei-infected mice. However, a rise in parasitaemia levels was observed on day 6 and on day 9 for chloroquine-treated mice.ConclusionThe hybrid compounds that were tested were able to reduce parasitaemia levels in P. berghei-infected mice when dosed intravenously, but parasites recrudesced 24h after the administration of the least dose. Despite low oral bioavailability, the IV data obtained suggests that further structural modifications may lead to the identification of more HPO-CQ hybrids with improved pharmacokinetic properties and in vivo efficacy

    Pancreatic polypeptide inhibits somatostatin secretion

    Get PDF
    AbstractPancreatic polypeptide (PP) is a major agonist for neuropeptide Y4 receptors (NPY4R). While NPY4R has been identified in various tissues, the cells on which it is expressed and its function in those cells has not been clearly delineated. Here we report that NPY4R is present in all somatostatin-containing cells of tissues that we tested, including pancreatic islets, duodenum, hippocampus, and hypothalamus. Its agonism by PP decreases somatostatin secretion from human islets. Mouse embryonic hippocampal (mHippo E18) cells expressed NPY4Rs and their activation by PP consistently decreased somatostatin secretion. Furthermore, central injection of PP in mice induced c-Fos immunoreactivity in somatostatin-containing cells in the hippocampus compared with PBS-injected mice. In sum, our results identify PP as a pivotal modulator of somatostatin secretion

    Cryptic diversity in the North American Dromochorus tiger beetles (Coleoptera: Carabidae: Cicindelinae): a congruence-based method for species discovery

    Get PDF
    A fundamental problem in biodiversity science is determining the number of species in any taxon, and there is a growing awareness that cryptic diversity contributes to this problem – even in well-studied groups. Discovering cryptic species requires several lines of evidence to elucidate congruent patterns across data-types, and distinguish unrecognized species. Tiger beetles are among the most well-studied insect groups; yet few new North American species have been described since the mid-20th century, suggesting that that the number of morphologically distinct species is reaching an asymptote. We explore the possibility that more species exist in the fauna as cryptic species, by analysing a broad geographic sample of all species in the genus Dromochorus. We employ a ‘taxonomic congruence’ approach, where we first generate species hypotheses from patterns of reciprocal monophyly across the mitochondrial and nuclear datasets, and test these hypotheses through congruence with population structure, morphological measures and ecological divergence. We find broad congruence that supports eight species of Dromochorus, more than doubling the known diversity. We also validate a previously ambiguous taxon, and re-describe previously named species. Lastly, we identify new diagnostic morphological characters, include an updated dichotomous key and provide updated natural history/ecological characteristics for the genus and individual species
    corecore