2,240 research outputs found
Risk Analysis for Information Systems
This paper presents an integrated approach to risk analysis for Information Systems (IS) using the Structured Risk Analysis (SRA) methodology developed at Hyperion. SRA has been used, very successfully, to perform risk analysis both for security-oriented risk analysis in the City and safety-oriented risk analysis for the European Space Agency. This paper develops and describes a particular instance of the SRA methodology for IS. Excluding safety-critical applications allows certain simplifications to the methodology in the case of IS. These simplifications make structured risk analysis for information systems (SRA-IS) a practical and cost-effective basis for risk analysis and risk management in commercial organizations
15 years of comet photometry: A comparative analysis of 80 comets
In 1976 we began a program of narrowband photometry of comets that has encompassed well over 400 nights of observations. To date, the program has provided detailed information on 80 comets, 11 of which have been observed on multiple apparitions. In this paper we present the observed range of compositions (molecular production rate ratios) and dustiness (gas production compared with AF-rho) for a well sampled group of comets. Based on these results we present preliminary analysis of taxonomic groupings as well as the abundance ratios we associate with a 'typical' comet
Adaptive feedback analysis and control of programmable stimuli for assessment of cerebrovascular function
The assessment of cerebrovascular regulatory mechanisms often requires flexibly controlled and precisely timed changes in arterial blood pressure (ABP) and/or inspired CO2. In this study, a new system for inducing variations in mean ABP was designed, implemented and tested using programmable sequences and programmable controls to induce pressure changes through bilateral thigh cuffs. The system is also integrated with a computer-controlled switch to select air or a CO2/air mixture to be provided via a face mask. Adaptive feedback control of a pressure generator was required to meet stringent specifications for fast changes, and accuracy in timing and pressure levels applied by the thigh cuffs. The implemented system consists of a PC-based signal analysis/control unit, a pressure control unit and a CO2/air control unit. Initial evaluations were carried out to compare the cuff pressure control performances between adaptive and non-adaptive control configurations. Results show that the adaptive control method can reduce the mean error in sustaining target pressure by 99.57 % and reduce the transient time in pressure increases by 45.21 %. The system has proven a highly effective tool in ongoing research on brain blood flow control
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Reliability of Semiautomated Kinetic Perimetry (SKP) and Goldmann Kinetic Perimetry in Children and Adults With Retinal Dystrophies.
PurposeTo investigate the precision of visual fields (VFs) from semiautomated kinetic perimetry (SKP) on Octopus 900 perimeters, for children and adults with inherited retinal degenerations (IRDs). Goldmann manual kinetic perimetry has long been used in the diagnosis and follow-up of these patients, but SKP is becoming increasingly common. Octopus VFs (OVFs) and Goldmann VFs (GVFs) were both mapped on two occasions.MethodsNineteen females and 10 males with IRDs were tested on OVFs and GVFs, with two targets per test (V4e and one smaller target). Tests were performed in the same (randomized) order at two visits about 1 week apart. The VFs were digitized to derive isopter solid angles. Comparisons, within and between visits, were performed with paired t-tests and Bland-Altman plots.ResultsMedian age was 20 years (range, 7-70; 10 participants aged β€17 years old). There were no significant differences in solid angles between OVFs and GVFs (P β₯ 0.06) or between the two visits' solid angles on either perimeter (P β₯ 0.30). Between-visit test-retest variability for GVFs and OVFs was similar (P β₯ 0.73), with median values of approximately 9% to 13%. Overall variability was lower for children than adults (medians of 7.5% and 12.8%, respectively).ConclusionsOctopus SKP and Goldmann perimetry produced VFs of similar size and variability.Translational relevanceOur study indicates that SKP provides a viable alternative to traditional Goldmann perimetry in clinical trials or care involving both children and adults with IRDs
Public/community Health Education Professional Accreditation among Stand-alone Baccalaureate Programs
Background and Purpose: Formal training for health promotion practitioners often includes academic study in health education. Accreditation is an important quality assurance mechanism. One concern expressed during Council of Education for Public Health (CEPH) professional meetings is the capacity of stand-alone undergraduate programs in health education to meet the demands of accreditation. The purpose of this study was to determine the accreditation knowledge level among the program directors of stand-alone programs, and identify the perceived challenges, support for and value ascribed to accreditation among these programs operating without an affiliated graduate program. Methods: Thirtyfive undergraduate program coordinators identified via the 2009 American Association for Health Education (AAHE) directory completed a 21-item survey instrument. Results: Most program coordinators knew about undergraduate accreditation requirements (82.9%), but program coordinators of self-identified small programs had significantly more concerns about the availability of resources needed to successfully attain accreditation. Conclusion: It is important to consider and provide resources for successful attainment of accreditation among smaller undergraduate institutions. Information regarding this general concern will be important to both the CEPH and academic program coordinators as they move forward with the new stand-alone baccalaureate accreditation initiative
Detection of impaired cerebral autoregulation improves by increasing arterial blood pressure variability
Although the assessment of dynamic cerebral autoregulation (CA) based on measurements of spontaneous fluctuations in arterial blood pressure (ABP) and cerebral blood flow (CBF) is a convenient and much used method, there remains uncertainty about its reliability. We tested the effects of increasing ABP variability, provoked by a modification of the thigh cuff method, on the ability of the autoregulation index to discriminate between normal and impaired CA, using hypercapnia as a surrogate for dynamic CA impairment. In 30 healthy volunteers, ABP (Finapres) and CBF velocity (CBFV, transcranial Doppler) were recorded at rest and during 5% CO(2) breathing, with and without pseudo-random sequence inflation and deflation of bilateral thigh cuffs. The application of thigh cuffs increased ABP and CBFV variabilities and was not associated with a distortion of the CBFV step response estimates for both normocapnic and hypercapnic conditions (P=0.59 and P=0.96, respectively). Sensitivity and specificity of CA impairment detection were improved with the thigh cuff method, with the area under the receiver-operator curve increasing from 0.746 to 0.859 (P=0.031). We conclude that the new method is a safe, efficient, and appealing alternative to currently existing assessment methods for the investigation of the status of CA
Major issues and solutions to applied climate education in Australia
In the past decade, Australian agriculture has evolved considerably. During this period, climate variability has been of considerable concern, compounded recently by the threat of climate change. Applied climate education has attempted to keep up-to-date with these developments. Understanding the issues and solutions to applied climate education is a challenge confronting agriculture in Australia. This paper reports on the major issues and solutions to applied climate education in Australia as identified in the literature
Detecting Lysozyme unfolding via the fluorescence of Lysozyme encapsulated gold nanoclusters
Protein misfolding plays a critical role in the formation of Amyloidosis type disease. Therefore, understanding and ability to track protein unfolding in a dynamic manner is of considerable interest. Fluorescence-based techniques are powerful tools for gaining real-time information about the local environmental conditions of a probe on the nanoscale. Fluorescent gold nanoclusters (AuNCs) are a new type of fluorescent probes which are <2 nm in diameter, incredibly robust and offer highly sensitive, wavelength tuneable emission. Their small size minimises intrusion and makes AuNCs ideal for studying protein dynamics. Lysozyme has previously been used to encapsulate AuNCs. The unfolding dynamics of Lysozyme under different environmental conditions have been well-studied and being an Amyloid type protein, makes Lysozyme an ideal candidate for encapsulating AuNCs in order to test their sensitivity to protein unfolding. In this study, we tracked the fluorescence characteristics of AuNCs encapsulated in Lysozyme while inducing protein unfolding by Urea, Sodium Dodecyl Sulphate (SDS) and elevated temperature and compared them to complimentary Circular Dichroism spectra. It is found that AuNC fluorescence emission is quenched upon induced protein unfolding either due to a decrease in Forster Resonance Energy Transfer (FRET) efficiency between tryptophan and AuNCs or solvent exposure of the AuNC. Fluorescence lifetime measurements confirmed quenching to be collisional via oxygen dissolved in a solution; increasing as the AuNC was exposed to the solvent during unfolding. Moreover, the longer decay component Ο1 was observed to decrease as the protein unfolded, due to the increased collisional quenching. It is suggested that AuNC sensitivity to solvent exposure might be utilised in the future as a new approach to studying and possibly even detecting Amyloidosis type diseases
The very large G-protein coupled receptor VLGR1: a component of the ankle link complex required for the normal development of auditory hair bundles
Sensory hair bundles in the inner ear are composed of stereocilia that can be interconnected by a variety of different link types, including tip links, horizontal top connectors, shaft connectors, and ankle links. The ankle link antigen is an epitope specifically associated with ankle links and the calycal processes of photoreceptors in chicks. Mass spectrometry and immunoblotting were used to identify this antigen as the avian ortholog of the very large G-protein-coupled receptor VLGR1, the product of the Usher syndrome USH2C (Mass1) locus. Like ankle links, Vlgr1 is expressed transiently around the base of developing hair bundles in mice. Ankle links fail to form in the cochleae of mice carrying a targeted mutation in Vlgr1 (Vlgr1/del7TM), and the bundles become disorganized just after birth. FM1-43 [N-(3-triethylammonium)propyl)-4-(4-(dibutylamino)styryl) pyridinium dibromide] dye loading and whole-cell recordings indicate mechanotransduction is impaired in cochlear, but not vestibular, hair cells of early postnatal Vlgr1/del7TM mutant mice. Auditory brainstem recordings and distortion product measurements indicate that these mice are severely deaf by the third week of life. Hair cells from the basal half of the cochlea are lost in 2-month-old Vlgr1/del7TM mice, and retinal function is mildly abnormal in aged mutants. Our results indicate that Vlgr1 is required for formation of the ankle link complex and the normal development of cochlear hair bundles
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