72 research outputs found
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Airborne Particulate Threat Assessment
Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our findings and APICD Gen II subsystems for automated collection, deposition and detection of ambient particulate matter. Key findings from the APTA Program include: Ambient biological PM taxonomy; Demonstration of key subsystems needed for autonomous bioaerosol detection; System design; Efficient electrostatic collection; Automated bioagent recognition; Raman analysis performance validating Td<9 sec; Efficient collection surface regeneration; and Development of a quantitative bioaerosol defection model. The objective of the APTA program was to advance the state of our knowledge of ambient background PM composition. Operation of an automated aerosol detection system was enhanced by a more accurate assessment of background variability, especially for sensitive and specific sensing strategies like Raman detection that are background-limited in performance. Based on this improved knowledge of background, the overall threat detection performance of Raman sensors was improved
The international school psychology survey: Data from Australia, China, Germany, Italy and Russia
Using the International School Psychology Survey (ISPS) this study aims to advance our knowledge of the characteristics, training, roles and responsibilities, challenges and research interests of school psychologists around the world. Data are presented from five countries; Australia, China (Hong Kong), Germany, Italy and Russia. The ISPS contributes valuable information regarding the profession of school psychology in each of these countries. Building upon the ISPS data previously gathered in Albania, Cyprus, Estonia, Greece and Northern England, this study yields additional information regarding the training, roles, responsibilities and contexts of school psychologists. Information from international colleagues provides unique insights regarding similarities, differences and diversity among school psychologists in different countries. © 2006 SAGE Publications.postprin
Breeding of Vicia faba L. in relation to drought resistance
The Yu.N. Kurkina field method was used to determine the drought tolerance of bean plants. An analysis of the totality of ecological and morphological traits of forage bean varieties of different origins revealed varieties with pronounced xeromorphicity with low plant heights and narrow leaves. The varieties with high drought resistance have been identifie
Aβ1-16 controls synaptic vesicle pools at excitatory synapses via cholinergic modulation of synapsin phosphorylation
Amyloid beta (Aβ) is linked to the pathology of Alzheimer’s disease (AD). At physiological concentrations, Aβ was proposed to enhance neuroplasticity and memory formation by increasing the neurotransmitter release from presynapse. However, the exact mechanisms underlying this presynaptic effect as well as specific contribution of endogenously occurring Aβ isoforms remain unclear. Here, we demonstrate that Aβ1-42 and Aβ1-16, but not Aβ17-42, increased size of the recycling pool of synaptic vesicles (SV). This presynaptic effect was driven by enhancement of endogenous cholinergic signalling via α7 nicotinic acetylcholine receptors, which led to activation of calcineurin, dephosphorylation of synapsin 1 and consequently resulted in reorganization of functional pools of SV increasing their availability for sustained neurotransmission. Our results identify synapsin 1 as a molecular target of Aβ and reveal an effect of physiological concentrations of Aβ on cholinergic modulation of glutamatergic neurotransmission. These findings provide new mechanistic insights in cholinergic dysfunction observed in AD
Intracellular Ca2+ and not the extracellular matrix determines surface dynamics of AMPA-type glutamate receptors on aspiny neurons
The perisynaptic extracellular matrix (ECM) contributes to the control of the lateral mobility of AMPA-type glutamate receptors (AMPARs) at spine synapses of principal hippocampal neurons. Here, we have studied the effect of the ECM on the lateral mobility of AMPARs at shaft synapses of aspiny interneurons. Single particle tracking experiments revealed that the removal of the hyaluronan-based ECM with hyaluronidase does not affect lateral receptor mobility on the timescale of seconds. Similarly, cross-linking with specific antibodies against the extracellular domain of the GluA1 receptor subunit, which affects lateral receptor mobility on spiny neurons, does not influence receptor mobility on aspiny neurons. AMPARs on aspiny interneurons are characterized by strong inward rectification indicating a significant fraction of Ca2+-permeable receptors. Therefore, we tested whether Ca2+ controls AMPAR mobility in these neurons. Application of the membrane-permeable Ca2+ chelator BAPTA-AM significantly increased the lateral mobility of GluA1-containing synaptic and extrasynaptic receptors. These data indicate that the perisynaptic ECM affects the lateral mobility differently on spiny and aspiny neurons. Although ECM structures on interneurons appear much more prominent, their influence on AMPAR mobility seems to be negligible at short timescales
Expression of a unique plastid-localized heat-shock protein is genetically linked to acquired thermotolerance in wheat
We have used a combination of molecular and classical genetic approaches to delineate the relationship between a specific HSP member and cell viability under heat stress. Using recombinant inbred lines (RILs) of wheat, derived from a cross of the thermotolerant cultivar \u27Mustang\u27 and the thermosusceptible cultivar \u27Sturdy,\u27 we have identified a unique HSP and a differentially expressed cDNA sequence, both related to the plastid-localized HSP26 gene family, that are closely associated with acquired thermotolerance in wheat. An isoform of HSP26 was synthesized under heat stress in all examined thermotolerant RILs and \u27Mustang\u27, and was absent in all examined thermosusceptible RILs and \u27Sturdy.\u27 Using a modified differential-display method, we have also identified a gene-specific cDNA sequence that is similar to other known members of the wheat HSP26 gene family and is selectively expressed in \u27Mustang\u27 and most of the examined thermotolerant RILs, but not expressed in \u27Sturdy\u27 and all the thermosusceptible RILs. These results suggest a genetic linkage between the acquired thermotolerance trait and the differential expression of a unique member of the HSP26 gene family
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