Reliability and performance evaluation of systems containing embedded rule-based expert systems

A method for evaluating the reliability of real-time systems containing embedded rule-based expert systems is proposed and investigated. It is a three stage technique that addresses the impact of knowledge-base uncertainties on the performance of expert systems. In the first stage, a Markov reliability model of the system is developed which identifies the key performance parameters of the expert system. In the second stage, the evaluation method is used to determine the values of the expert system's key performance parameters. The performance parameters can be evaluated directly by using a probabilistic model of uncertainties in the knowledge-base or by using sensitivity analyses. In the third and final state, the performance parameters of the expert system are combined with performance parameters for other system components and subsystems to evaluate the reliability and performance of the complete system. The evaluation method is demonstrated in the context of a simple expert system used to supervise the performances of an FDI algorithm associated with an aircraft longitudinal flight-control system

Management and radiographic outcomes of femoral head fractures.

BackgroundFemoral head fractures are uncommon injuries. Small series constitute the majority of the available literature. Surgical approach and fracture management is variable. The purpose of this study was to evaluate the incidence, method of treatment, and outcomes of consecutive femoral head fractures at a regional academic Level I trauma center.Materials and methodsA retrospective review of a prospective database was performed over a 13-year period. All AO/OTA 31C femoral head fractures were identified. A surgical approach and fixation method was recorded. Clinical and radiographic evaluation was performed for patients with 6 months or greater follow-up. Radiographs were evaluated for fixation failure, heterotopic ossification (HO), avascular necrosis (AVN) and post-traumatic arthritis.ResultsWe identified 164 fractures in 163 patients; 147 fractures were available for review. Treatment was operative reduction and internal fixation (ORIF) in 78 (53.1%), fragment excision in 37 (25.1%) and non-operative in 28 (19%). An anterior approach and mini-fragment screws were used in the majority of patients treated with fixation. Sixty-nine fractures had follow-up greater than 6 months. Sixty-two fractures (89.9%) proceeded to uneventful union. All Pipkin III fractures failed operative fixation. Six patients developed AVN, seven patients had a known conversion to hip arthroplasty; HO developed in 28 (40.6%) patients and rarely required excision.ConclusionsFractures of the femoral head are rare. An anterior approach can be used for fragment excision or fixation using mini-fragment screws. Pipkin III fractures represent catastrophic injuries. Non-bridging, asymptomatic HO is common. AVN and posttraumatic degenerative disease of the hip occur but are uncommon.Level of evidenceIV-prognostic

In vitro antibacterial activity of tissue extracts from four channids against enteric pathogens

In vitro antibacterial activity of tissue extracts from four channids against enteric pathogens. International Journal of Agricultural Technology 9(6):1437-1445. Abstract The aim of this study was to identify the presence of antimicrobial activity in tissues of selected Channa species. Atotal of 20 solvent fractions from the tissue were obtained by solid-phase extraction and the fractions were assayed for antimicrobial activity. The screening of antimicrobial activity for all the fractions were tested against five enteric pathogens including Salmonella typhi, Staphylococcus aureus, Klebsiella vulgaris, Shigella dysenteriae, Shigella boydii. The activity was measured in terms of zone of inhibition in mm. The tissue that showed efficient antibacterial activity was subjected to SDS-PAGE to find out the molecular weights. Efficient antibacterial activity was observed from the methanol extract of all the Channa species. A maximum zone of inhibition was observed in Channa striatus against Shigelladysenteriae. It is therefore suggested that Channa striatus can be a potential source of an antimicrobial protein for specific human pathogens

Bulletin No. 341 - Rambouillet and Columbia-Rambouillet Lambs on the Range and in the Feed Lot

Sheep of predominately Rambouillet breeding have been most popular on southern Utah ranges because of their hardiness and wool-producing ability. In the early years of sheep production in Utah a major portion of the income was derived from the sale of wool. This situation has gradually changed over the past years and now income from the sale of lambs is greater than that from fleeces. Rambouillet rams with improved mutton qualities have been used by some range operators to increase the mutton producing abilities of their ewes. Other operators have used Corriedale, Panama, Columbia, and other white faced crossbred-type rams to achieve more speedily the desired mutton qualities. Because of the interest of Utah sheepmen in the problem of improving their range ewes, the Utah Agricultural Experiment Station, in cooperation with the Branch Agricultural College at Cedar City, established a range sheep unit at Cedar City in 1943 and 1944. This unit has been used to conduct controlled breeding studies aimed at the determination of the type or breed of sheep most desirable for southern Utah range conditions. This bulletin reviews the initial results and gives attention particularly to the qualities of the lambs produced by mating Columbia rams to grade Rambouillet range ewes compared to those produced by mating Rambouillet rams to ewes similar to those bred to the Columbias

3. Launching the New Enterprise

As the academic year of 1945-46 approached, the intensity of activity in preparation for actually opening the school in the fall term became overwhelming. Incredible though it may seem, Ives and Day were able in a period of a few weeks to assemble the nucleus of a faculty, several of whom formed a continuing source of counsel and advice both during the school’s formative years and thereafter. Includes: The First Dean and the School’s Dedication; A Participant’s View of the Early Years; Ives Moves On; Several Views of Martin P. Catherwood; The Founders

Computer Game Play Reduces Intrusive Memories of Experimental Trauma via Reconsolidation-Update Mechanisms.

Memory of a traumatic event becomes consolidated within hours. Intrusive memories can then flash back repeatedly into the mind's eye and cause distress. We investigated whether reconsolidation-the process during which memories become malleable when recalled-can be blocked using a cognitive task and whether such an approach can reduce these unbidden intrusions. We predicted that reconsolidation of a reactivated visual memory of experimental trauma could be disrupted by engaging in a visuospatial task that would compete for visual working memory resources. We showed that intrusive memories were virtually abolished by playing the computer game Tetris following a memory-reactivation task 24 hr after initial exposure to experimental trauma. Furthermore, both memory reactivation and playing Tetris were required to reduce subsequent intrusions (Experiment 2), consistent with reconsolidation-update mechanisms. A simple, noninvasive cognitive-task procedure administered after emotional memory has already consolidated (i.e., > 24 hours after exposure to experimental trauma) may prevent the recurrence of intrusive memories of those emotional events

Miniature Toroidal Radio Frequency Ion Trap Mass Analyzer

A miniature ion trap mass analyzer is reported. The described analyzer is a 1/5-scale version of a previously reported toroidal radio frequency (rf) ion trap mass analyzer. The toroidal ion trap operates with maximum rf trapping voltages about 1 kVp-p or less; however despite the reduced dimensions, it retains roughly the same ion trapping capacity as conventional 3D quadrupole ion traps. The curved geometry provides for a compact mass analyzer. Unit-mass resolved mass spectra for n-butylbenzene, xenon, and naphthalene are reported and preliminary sensitivity data are shown for naphthalene. The expected linear mass scale with rf amplitude scan is obtained when scanned using a conventional mass-selective instability scan mode combined with resonance ejection