Independent Orbiter Assessment (IOA): Analysis of the orbiter main propulsion system

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Main Propulsion System (MPS) hardware are documented. The Orbiter MPS consists of two subsystems: the Propellant Management Subsystem (PMS) and the Helium Subsystem. The PMS is a system of manifolds, distribution lines and valves by which the liquid propellants pass from the External Tank (ET) to the Space Shuttle Main Engines (SSMEs) and gaseous propellants pass from the SSMEs to the ET. The Helium Subsystem consists of a series of helium supply tanks and their associated regulators, check valves, distribution lines, and control valves. The Helium Subsystem supplies helium that is used within the SSMEs for inflight purges and provides pressure for actuation of SSME valves during emergency pneumatic shutdowns. The balance of the helium is used to provide pressure to operate the pneumatically actuated valves within the PMS. Each component was evaluated and analyzed for possible failure modes and effects. Criticalities were assigned based on the worst possible effect of each failure mode. Of the 690 failure modes analyzed, 349 were determined to be PCIs

Enhanced nasopharyngeal infection and shedding associated with an epidemic lineage of emm3 group A Streptococcus

Background: A group A Streptococcus (GAS) lineage of genotype emm3, sequence type 15 (ST15) was associated with a six month upsurge in invasive GAS disease in the UK. The epidemic lineage (Lineage C) had lost two typical emm3 prophages, Φ315.1 and Φ315.2 associated with the superantigen ssa, but gained a different prophage (ΦUK-M3.1) associated with a different superantigen, speC and a DNAse spd1. Methods and Results: The presence of speC and spd1 in Lineage C ST15 strains enhanced both in vitro mitogenic and DNAse activities over non-Lineage C ST15 strains. Invasive disease models in Galleria mellonella and SPEC-sensitive transgenic mice, revealed no difference in overall invasiveness of Lineage C ST15 strains compared to non-Lineage C ST15 strains, consistent with clinical and epidemiological analysis. Lineage C strains did however markedly prolong murine nasal infection with enhanced nasal and airborne shedding compared to non-Lineage C strains. Deletion of speC or spd1 in two Lineage C strains identified a possible role for spd1 in airborne shedding from the murine nasopharynx. Conclusions: Nasopharyngeal infection and shedding of Lineage C strains was enhanced compared to nonLineage C strains and this was, in part, mediated by the gain of the DNase spd1 through prophage acquisition

Absence of stimulus-driven synchronization effects on sensory perception in autism: Evidence for local underconnectivity?

<p>Abstract</p> <p>Background</p> <p>A number of neurophysiological characteristics demonstrated in autism share the common theme of under-connectivity in the cerebral cortex. One of the prominent theories of the cause of the dysfunctional connectivity in autism is based on distinct anatomical structures that differ between the autistic and the neurotypical cortex. The functional minicolumn has been identified as occupying a much smaller space in the cortex of people with autism as compared to neurotypical controls, and this aberration in architecture has been proposed to lead to under-connectivity at the local or within-macrocolumn level, which in turn leads to dysfunctional connectivity globally across cortical areas in persons with autism. Numerous reports have indicated reduced synchronization of activity on a large scale in the brains of people with autism. We hypothesized that if the larger-scale aberrant dynamics in autism were due – at least in part – to a widespread propagation of the errors introduced at the level of local connectivity between minicolumns, then aberrations in local functional connectivity should also be detectable in autism.</p> <p>Methods</p> <p>Recently, we reported a method for measuring the perceptual changes that are impacted by the presence of synchronized conditioning stimuli on the skin. In this study, the temporal order judgment (TOJ) and temporal discriminative threshold (TDT) of 10 adult autism subjects were assessed both in the absence and presence of synchronized conditioning vibrotactile stimuli.</p> <p>Results</p> <p>Our previous report demonstrated that delivering simultaneous and synchronized vibrotactile stimuli to near-adjacent skin sites decreases a subject's ability to determine temporal order by 3 to 4-fold. However, results presented in this report show that subjects with autism do not demonstrate such decreased capacity in temporal order judgment (TOJ) in the presence of synchronized conditioning stimuli, although these same subjects do have TOJ thresholds well above that of controls.</p> <p>Conclusion</p> <p>It is speculated that the differences in sensory perceptual capacities in the presence of synchronized conditioning stimuli in autism are due to local under-connectivity in cortex at the minicolumnar organizational level, and that the above-average TOJ thresholds in autism could be attributed to structural differences that have been observed in the frontostrial system of this population.</p

Use of the nominal group technique to identify UK stakeholder views of the measures and domains used in the assessment of therapeutic exercise adherence for patients with musculoskeletal disorders

OBJECTIVES: The objective was to the undertake nominal group technique (NGT) to evaluate current exercise adherence measures and isolated domains to develop stakeholder consensus on the domains to include in the measurement of therapeutic exercise adherence for patients with musculoskeletal disorders. DESIGN: A 1-day NGT workshop was convened. Six exercise adherence measures were presented to the group that were identified in our recent systematic review. Discussions considered these measures and isolated domains of exercise adherence. Following discussions, consensus voting identified stakeholder agreement on the suitability of the six offered adherence measures and the inclusion of isolated domains of exercise adherence in future measurement. SETTING: One stakeholder NGT workshop held in Sheffield, UK. PARTICIPANTS: Key stakeholders from the UK were invited to participate from four identified populations. 14 participants represented patients, clinicians, researchers and service managers. RESULTS: All six exercise adherence measures were deemed not appropriate for use in clinical research or routine practice with no measure reaching 70% group agreement for suitability, relevance, acceptability or appropriateness. Three measures were deemed feasible to use in clinical practice. 25 constructs of exercise adherence did reach consensus threshold and were supported to be included as domains in the future measurement of exercise adherence. CONCLUSION: A mixed UK-based stakeholder group felt these six measures of exercise adherence were unacceptable. Differences in opinion within the stakeholder group highlighted the lack of consensus as to what should be measured, the type of assessment that is required and whose perspective should be sought when assessing exercise adherence. Previously unused domains may be needed alongside current ones, from both a clinician's and patient's perspective, to gain understanding and to inform future measurement development. Further conceptualisation of exercise adherence is required from similar mixed stakeholder groups in various socioeconomic and cultural populations

TFE3 Translocation-Associated Renal Cell Carcinoma Presenting as Avascular Necrosis of the Femur in a 19-Year-Old Patient: Case Report and Review of the Literature

In the United States, renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and 90–95% of all neoplasms arising from the kidney. According to the National Cancer Institute, 58 240 new cases and 13 040 deaths from renal cancer will occur in 2010. RCC usually occurs in older adults between the ages of 50 and 70 and is rare in young adults and children. We describe a case of a TFE3 translocation-associated RCC in a 19-year-old patient presenting as avascular necrosis of the femur. Due to the rarity of this malignancy, we present this case including a review of the existing literature relative to diagnosis and treatment

Superclustering at Redshift Z=0.54

We present strong evidence for the existence of a supercluster at a redshift of z=0.54 in the direction of Selected Area 68. From the distribution of galaxies with spectroscopic redshifts we find that there is a large over-density of galaxies (a factor of four over the number expected in an unclustered universe) within the redshift range 0.530 < z < 0.555. By considering the spatial distribution of galaxies within this redshift range (using spectroscopic and photometric redshifts) we show that the galaxies in SA68 form a linear structure passing from the South-West of the survey field through to the North-East (with a position angle of approximately 35 deg East of North). This position angle is coincident with the positions of the X-ray clusters CL0016+16, RX J0018.3+1618 and a new X-ray cluster, RX J0018.8+1602, centered near the radio source 54W084. All three of these sources are at a redshift of approximately z=0.54 and have position angles, derived from their X-ray photon distributions, consistent with that measured for the supercluster. Assuming a redshift of 0.54 for the distribution of galaxies and a FWHM dispersion in redshift of 0.020 this represents a coherent structure with a radial extent of 31 Mpc, transverse dimension of 12 Mpc, and a thickness of approximately 4 Mpc. The detection of this possible supercluster demonstrates the power of using X-ray observations, combined with multicolor observations, to map the large scale distribution of galaxies at intermediate redshifts.Comment: 12 pages, 3 figures, Latex, aaspp4.sty, accepted for publication in Ap J Letters. Figure 3 and followup observations can be found at http://tarkus.pha.jhu.edu/~ajc/papers/supercluster

Complex Patterns in Reaction-Diffusion Systems: A Tale of Two Front Instabilities

Two front instabilities in a reaction-diffusion system are shown to lead to the formation of complex patterns. The first is an instability to transverse modulations that drives the formation of labyrinthine patterns. The second is a Nonequilibrium Ising-Bloch (NIB) bifurcation that renders a stationary planar front unstable and gives rise to a pair of counterpropagating fronts. Near the NIB bifurcation the relation of the front velocity to curvature is highly nonlinear and transitions between counterpropagating fronts become feasible. Nonuniformly curved fronts may undergo local front transitions that nucleate spiral-vortex pairs. These nucleation events provide the ingredient needed to initiate spot splitting and spiral turbulence. Similar spatio-temporal processes have been observed recently in the ferrocyanide-iodate-sulfite reaction.Comment: Text: 14 pages compressed Postscript (90kb) Figures: 9 pages compressed Postscript (368kb

Building professional discourse in emerging markets: Language, context and the challenge of sensemaking

Using ethnographic evidence from the former Soviet republics, this article examines a relatively new and mainly unobserved in the International Business (IB) literature phenomenon of communication disengagement that manifests itself in many emerging markets. We link it to the deficiencies of the local professional business discourse rooted in language limitations reflecting lack of experience with the market economy. This hampers cognitive coherence between foreign and local business entities, adding to the liability of foreignness as certain instances of professional experience fail to find adequate linguistic expression, and complicates cross-cultural adjustments causing multi-national companies (MNCs) financial losses. We contribute to the IB literature by examining cross-border semantic sensemaking through a retrospectively constructed observational study. We argue that a relative inadequacy of the national professional idiom is likely to remain a feature of business environment in post-communist economies for some time and therefore should be factored into business strategies of MNCs. Consequently, we recommend including discursive hazards in the risk evaluation of international projects