66 research outputs found

    Scan mirror remote temperature sensing system and method

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    A remote temperature sensing system (10) for a scanning mirror (7). The system (10) includes a sensor which detects heat radiated by the mirror and provides a signal in response thereto. In the illustrative implementation, the system (10) includes a thermistor mounted within a housing. The housing is contoured to maximize the receipt of thermal energy thereby. A mounting assembly maintains the thermistor a predetermined nonzero distance from the scanning mirror (7). The invention includes a shroud (12) mounted on the mirror (7) for shielding the thermistor and a support tube connected to the thermistor housing on a first end and to a base on the second end thereof. The support tube is adapted to remain stationary within the shroud as the scanning mirror and the shroud rotate due to the scanning of the mirror. Wires are connected to the thermistor on a first end thereof and are wrapped around the support tube. The wires include a length of electrically conductive material having a resistivity which has a low sensitivity to temperature variations. The sensor output is processed in a conventional manner to provide an output indicative of the temperature of the mirror

    New Perspectives on Glacial Geomorphology in Earth's Deep Time Record

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    International audienceThe deep time (pre-Quaternary) glacial record is an important means to understand the growth, development, and recession of the global cryosphere on very long timescales (10 6-10 8 Myr). Sedimentological description and interpretation of outcrops has traditionally played an important role. Whilst such data remain vital, new insights are now possible thanks to freely accessible aerial and satellite imagery, the widespread availability and affordability of Uncrewed Aerial Vehicles, and accessibility to 3D rendering software. In this paper, we showcase examples of glaciated landscapes from the Cryogenian, Ediacaran, Late Ordovician and Late Carboniferous where this approach is revolutionizing our understanding of deep time glaciation. Although some problems cannot be overcome (erosion or dissolution of the evidence), robust interpretations in terms of the evolving subglacial environment can be made. Citing examples from Australia (Cryogenian), China (Ediacaran), North and South Africa (Late Ordovician, Late Carboniferous), and Namibia (Late Carboniferous), we illustrate how the power of glacial geomorphology can be harnessed to interpret Earth's ancient glacial record

    A Multi-State Model of the CaMKII Dodecamer Suggests a Role for Calmodulin in Maintenance of Autophosphorylation

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    Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) accounts for up to 2 percent of all brain protein and is essential to memory function. CaMKII activity is known to regulate dynamic shifts in the size and signaling strength of neuronal connections, a process known as synaptic plasticity. Increasingly, computational models are used to explore synaptic plasticity and the mechanisms regulating CaMKII activity. Conventional modeling approaches may exclude biophysical detail due to the impractical number of state combinations that arise when explicitly monitoring the conformational changes, ligand binding, and phosphorylation events that occur on each of the CaMKII holoenzyme’s subunits. To manage the combinatorial explosion without necessitating bias or loss in biological accuracy, we use a specialized syntax in the software MCell to create a rule-based model of a twelve-subunit CaMKII holoenzyme. Here we validate the rule-based model against previous experimental measures of CaMKII activity and investigate molecular mechanisms of CaMKII regulation. Specifically, we explore how Ca²⁺/CaM-binding may both stabilize CaMKII subunit activation and regulate maintenance of CaMKII autophosphorylation. Noting that Ca²⁺/CaM and protein phosphatases bind CaMKII at nearby or overlapping sites, we compare model scenarios in which Ca²⁺/CaM and protein phosphatase do or do not structurally exclude each other’s binding to CaMKII. Our results suggest a functional mechanism for the so-called “CaM trapping” phenomenon, wherein Ca²⁺/CaM may structurally exclude phosphatase binding and thereby prolong CaMKII autophosphorylation. We conclude that structural protection of autophosphorylated CaMKII by Ca²⁺/CaM may be an important mechanism for regulation of synaptic plasticity

    Can-Pain-a digital intervention to optimise cancer pain control in the community : development and feasibility testing

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    Purpose: To develop a novel digital intervention to optimise cancer pain control in the community. This paper describes intervention development, content/rationale and initial feasibility testing. Methods: Determinants of suboptimal cancer pain management were characterised through two systematic reviews; patient, caregiver and healthcare professional (HCP) interviews (n = 39); and two HCP focus groups (n = 12). Intervention mapping was used to translate results into theory-based content, creating the app “Can-Pain”. Patients with/without a linked caregiver, their general practitioners and community palliative care nurses were recruited to feasibility test Can-Pain over 4 weeks. Results: Patients on strong opioids described challenges balancing pain levels with opioid intake, side effects and activities and communicating about pain management problems with HCPs. Can-Pain addresses these challenges through educational resources, contemporaneous short-acting opioid tracking and weekly patient-reported outcome monitoring. Novel aspects of Can-Pain include the use of contemporaneous breakthrough analgesic reports as a surrogate measure of pain control and measuring the level at which pain becomes bothersome to the individual. Patients were unwell due to advanced cancer, making recruitment to feasibility testing difficult. Two patients and one caregiver used Can-Pain for 4 weeks, sharing weekly reports with four HCPs. Can-Pain highlighted unrecognised problems, promoted shared understanding about symptoms between patients and HCPs and supported shared decision-making. Conclusions: Preliminary testing suggests that Can-Pain is feasible and could promote patient-centred pain management. We will conduct further small-scale evaluations to inform a future randomised, stepped-wedge trial

    Are luminescent bacteria suitable for online detection and monitoring of toxic compounds in drinking water and its sources?

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    Biosensors based on luminescent bacteria may be valuable tools to monitor the chemical quality and safety of surface and drinking water. In this review, an overview is presented of the recombinant strains available that harbour the bacterial luciferase genes luxCDABE, and which may be used in an online biosensor for water quality monitoring. Many bacterial strains have been described for the detection of a broad range of toxicity parameters, including DNA damage, protein damage, membrane damage, oxidative stress, organic pollutants, and heavy metals. Most lux strains have sensitivities with detection limits ranging from milligrams per litre to micrograms per litre, usually with higher sensitivities in compound-specific strains. Although the sensitivity of lux strains can be enhanced by various molecular manipulations, most reported detection thresholds are still too high to detect levels of individual contaminants as they occur nowadays in European drinking waters. However, lux strains sensing specific toxic effects have the advantage of being able to respond to mixtures of contaminants inducing the same effect, and thus could be used as a sensor for the sum effect, including the effect of compounds that are as yet not identified by chemical analysis. An evaluation of the suitability of lux strains for monitoring surface and drinking water is therefore provided

    Cloning of mnuA, a Membrane Nuclease Gene of Mycoplasma pulmonis, and Analysis of Its Expression in Escherichia coli

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    Membrane nucleases of mycoplasmas are believed to play important roles in growth and pathogenesis, although no clear evidence for their importance has yet been obtained. As a first step in defining the function of this unusual membrane activity, studies were undertaken to clone and analyze one of the membrane nuclease genes from Mycoplasma pulmonis. A novel screening strategy was used to identify a recombinant lambda phage expressing nuclease activity, and its cloned fragment was analyzed. Transposon mutagenesis was used to identify an open reading frame of 1,410 bp, which coded for nuclease activity in Escherichia coli. This gene coded for a 470-amino-acid polypeptide of 53,739 Da and was designated mnuA (for “membrane nuclease”). The MnuA protein contained a prolipoprotein signal peptidase II recognition sequence along with an extensive hydrophobic region near the amino terminus, suggesting that the protein may be lipid modified or that it is anchored in the membrane by this membrane-spanning region. Antisera raised against two MnuA peptide sequences identified an M. pulmonis membrane protein of approximately 42 kDa by immunoblotting, which corresponded to a trypsin-sensitive nucleolytic band of the same size. Maxicell experiments with E. coli confirmed that mnuA coded for a nuclease of unknown specificity. Hybridization studies showed that mnuA sequences are found in few Mycoplasma species, suggesting that mycoplasma membrane nucleases display significant sequence variation within the genus Mycoplasma
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