New methods and results for quantification of lightning-aircraft electrodynamics

The NASA F-106 collected data on the rates of change of electromagnetic parameters on the aircraft surface during over 700 direct lightning strikes while penetrating thunderstorms at altitudes from 15,000 t0 40,000 ft (4,570 to 12,190 m). These in situ measurements provided the basis for the first statistical quantification of the lightning electromagnetic threat to aircraft appropriate for determining indirect lightning effects on aircraft. These data are used to update previous lightning criteria and standards developed over the years from ground-based measurements. The proposed standards will be the first which reflect actual aircraft responses measured at flight altitudes. Nonparametric maximum likelihood estimates of the distribution of the peak electromagnetic rates of change for consideration in the new standards are obtained based on peak recorder data for multiple-strike flights. The linear and nonlinear modeling techniques developed provide means to interpret and understand the direct-strike electromagnetic data acquired on the F-106. The reasonable results obtained with the models, compared with measured responses, provide increased confidence that the models may be credibly applied to other aircraft

Ultrasound-Guided Lateral Femoral Cutaneous Nerve Cryoneurolysis for Analgesia in Patients With Burns.

Autologous skin grafting from the thigh is frequently required for treatment of burns and is associated with intense pain at the donor site. Local anesthetic-based (LA) nerve blocks of the lateral femoral cutaneous nerve (LFCN) have been demonstrated to provide analgesia when the graft is taken from the lateral thigh. However, the duration of these single injection blocks has been reported to average only 9 hours, whereas the pain from the procedure lasts days or weeks. Continuous LA nerve blocks can also be used to provide analgesia during serial debridement of burns, although this requires placement of a perineural catheter which may increase infection risk in a population with an increased susceptibility to infection. Cryoneurolysis of the LFCN can potentially provide analgesia of the lateral thigh for skin graft harvesting or serial burn debridement that lasts far longer than conventional LA nerve blocks. Here, we present a series of three patients who received a combination of a LA nerve block and cryoneurolysis nerve block of the LFCN for analgesia of the lateral thigh. Two of these patients had the blocks placed before harvesting a split thickness skin graft. The third received the blocks for outpatient wound care of a burn to the lateral thigh. In all cases, the resulting analgesia lasted more than 1 week. A single cryoneurolysis block of the LFCN successfully provided extended duration analgesia of the lateral thigh for autologous skin graft donor site or wound care of a burn in three patients

Physiotherapists’ use of airway clearance techniques during an acute exacerbation of bronchiectasis: a survey study

Abstract Background Airway clearance techniques are recommended for individuals with bronchiectasis both in stable state and during an acute exacerbation, however the current use of airway clearance techniques in the management of individuals during an acute exacerbation is unclear. The aims of this study were to establish what current physiotherapy clinical practice comprises for adults and paediatrics during an acute exacerbation of bronchiectasis; identify physiotherapist’s perceptions of the effectiveness of airway clearance techniques and identify what factors influence their treatment decisions in this population. Methods An anonymous online survey was distributed to the members of the Australian Physiotherapy Association and Physiotherapy New Zealand between August 2016 and April 2017. Results The survey was accessed by 130 physiotherapists and 121 of those deemed themselves eligible and consented to participate. Most participants (89%) reported prescribing airway clearance techniques for 81–100% of individuals during an acute exacerbation of bronchiectasis. The most commonly used airway clearance techniques with adults were huffing (92%), exercise (89%) and the active cycle of breathing technique (89%). The techniques perceived most effective for adults were physical exercise (100%), oscillating positive expiratory pressure devices (97%), directed huffing (95%) the active cycle of breathing technique (90%) and positive expiratory pressure (90%). The most commonly used airway clearance techniques for paediatric patients were: newborn-3 years - percussion (85%) and modified postural drainage (85%); 4–10 years - huffing (100%) and exercise (85%); 11–18 years - huffing (92%) and exercise (77%), active cycle of breathing technique (77%) and positive expiratory pressure therapy (77%). The techniques perceived most effective for paediatric patients were directed huffing (100%), percussion (100%) and positive expiratory pressure via a mask or mouthpiece (93%). The most commonly reported factors influencing choice of technique were patient clinical presentation (72%) and the presence/absence of contra-indications (72%). Conclusion This survey demonstrates that airway clearance techniques are routinely used as part of physiotherapy management of individuals experiencing an acute exacerbation of bronchiectasis, and that choice of technique and perceived effectiveness varies depending on the age of the patient

PU.1 positively regulates GATA-1 expression in mast cells

Coexpression of PU.1 and GATA-1 is required for proper specification of the mast cell lineage; however, in the myeloid and erythroid lineages, PU.1 and GATA-1 are functionally antagonistic. In this study, we report a transcriptional network in which PU.1 positively regulates GATA-1 expression in mast cell development. We isolated a variant mRNA isoform of GATA-1 in murine mast cells that is significantly upregulated during mast cell differentiation. This isoform contains an alternatively spliced first exon (IB) that is distinct from the first exon (IE) incorporated in the major erythroid mRNA transcript. In contrast to erythroid and megakaryocyte cells, in mast cells we show that PU.1 and GATA-2 predominantly occupy potential cis-regulatory elements in the IB exon region in vivo. Using reporter assays, we identify an enhancer flanking the IB exon that is activated by PU.1. Furthermore, we observe that in PU.1 -/- fetal liver cells, low levels of the IE GATA-1 isoform is expressed, but the variant IB isoform is absent. Reintroduction of PU.1 restores variant IB isoform and upregulates total GATA-1 protein expression, which is concurrent with mast cell differentiation. Our results are consistent with a transcriptional hierarchy in which PU.1, possibly in concert with GATA-2, activates GATA-1 expression in mast cells in a pathway distinct from that seen in the erythroid and megakaryocytic lineages. Copyright © 2010 by The American Association of Immunologists, Inc

Diagnosis of Fault Modes Masked by Control Loops with an Application to Autonomous Hovercraft Systems

This paper introduces a methodology for the design, testing and assessment of incipient failure detection techniques for failing components/systems of an autonomous vehicle masked or hidden by feedback control loops. It is recognized that the optimum operation of critical assets (aircraft, autonomous systems, etc.) may be compromised by feedback control loops by masking severe fault modes while compensating for typical disturbances. Detrimental consequences of such occurrences include the inability to detect expeditiously and accurately incipient failures, loss of control and inefficient operation of assets in the form of fuel overconsumption and adverse environmental impact. We pursue a systems engineering process to design, construct and test an autonomous hovercraft instrumented appropriately for improved autonomy. Hidden fault modes are detected with performance guarantees by invoking a Bayesian estimation approach called particle filtering. Simulation and experimental studies are employed to demonstrate the efficacy of the proposed methods

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Uses its C-Terminus to Regulate the A2B Adenosine Receptor

CFTR is an apical membrane anion channel that regulates fluid homeostasis in many organs including the airways, colon, pancreas and sweat glands. In cystic fibrosis, CFTR dysfunction causes significant morbidity/mortality. Whilst CFTR’s function as an ion channel has been well described, its ability to regulate other proteins is less understood. We have previously shown that plasma membrane CFTR increases the surface density of the adenosine 2B receptor (A2BR), but not of the β2 adrenergic receptor (β2AR), leading to an enhanced, adenosine-induced cAMP response in the presence of CFTR. In this study, we have found that the C-terminal PDZ-domain of both A2BR and CFTR were crucial for this interaction, and that replacing the C-terminus of A2BR with that of β2AR removed this CFTR-dependency. This observation extended to intact epithelia and disruption of the actin cytoskeleton prevented A2BR-induced but not β2AR-induced airway surface liquid (ASL) secretion. We also found that CFTR expression altered the organization of the actin cytoskeleton and PDZ-binding proteins in both HEK293T cells and in well-differentiated human bronchial epithelia. Furthermore, removal of CFTR’s PDZ binding motif (ΔTRL) prevented actin rearrangement, suggesting that CFTR insertion in the plasma membrane results in local reorganization of actin, PDZ binding proteins and certain GPCRs

Thermoneutrality alters gastrointestinal antigen passage patterning and predisposes to oral antigen sensitization in mice

Food allergy is an emerging epidemic, and the underlying mechanisms are not well defined partly due to the lack of robust adjuvant free experimental models of dietary antigen sensitization. As housing mice at thermoneutrality (Tn) - the temperature of metabolic homeostasis (26-30°C) - has been shown to improve modeling various human diseases involved in inflammation, we tested the impact of Tn housing on an experimental model of food sensitization. Here we demonstrate that WT BALB/c mice housed under standard temperature (18-20°C, Ts) conditions translocated the luminal antigens in the small intestine (SI) across the epitheliu

Re-examining the consumption-wealth relationship : the role of model uncertainty

This paper discusses the consumption-wealth relationship. Following the recent influential workof Lettau and Ludvigson [e.g. Lettau and Ludvigson (2001), (2004)], we use data on consumption, assets andlabor income and a vector error correction framework. Key …ndings of their work are that consumption doesrespond to permanent changes in wealth in the expected manner, but that most changes in wealth are transitoryand have no e¤ect on consumption. We investigate the robustness of these results to model uncertainty andargue for the use of Bayesian model averaging. We …nd that there is model uncertainty with regards to thenumber of cointegrating vectors, the form of deterministic components, lag length and whether the cointegratingresiduals a¤ect consumption and income directly. Whether this uncertainty has important empirical implicationsdepends on the researcher's attitude towards the economic theory used by Lettau and Ludvigson. If we workwith their model, our findings are very similar to theirs. However, if we work with a broader set of models andlet the data speak, we obtain somewhat di¤erent results. In the latter case, we …nd that the exact magnitudeof the role of permanent shocks is hard to estimate precisely. Thus, although some support exists for the viewthat their role is small, we cannot rule out the possibility that they have a substantive role to play

Source apportionment of organic carbon in Centreville, AL using organosulfates in organic tracer-based positive matrix factorization

Organic tracer-based positive matrix factorization (PMF) was used to apportion fine particulate (PM_(2.5)) organic carbon (OC) to its sources in Centreville, AL, USA, a rural forested site influenced by anthropogenic emissions, during the Southern Oxidant and Aerosol Study (SOAS) in the summer of 2013. Model inputs included organosulfates, a group of organic compounds that are tracers of anthropogenically-influenced biogenic secondary organic aerosols (SOA), as well as, OC, elemental carbon, water-soluble organic carbon, and other organic tracers for primary and secondary sources measured during day and night. The organic tracer-based PMF resolved eight factors that were identified as biomass burning (11%, average contribution to PM_(2.5) OC), vehicle emissions (8%), isoprene SOC formed under low-NO_x conditions (13%), isoprene SOC formed under high-NO_x conditions (11%), SOC formed by photochemical reactions (9%), oxidatively aged biogenic SOC (6%), sulfuric acid-influenced SOC (21%, that also includes isoprene and monoterpene SOC), and monoterpene SOC formed under high-NO_x conditions (21%). These results indicate that OC in Centreville during summer is mainly secondary in origin (81%). Fossil fuel combustion is the major source of NO_x, ozone, and sulfuric acid that play a key role in SOA formation in the southeastern US. Fossil fuel was found to influence 61–76% of OC through vehicle emissions and SOA formation. Together with prescribed burns, which were the major type of biomass burning during this study, the OC influenced by anthropogenic activities reached 87%. The organic tracer-based PMF results were further compared with two complementary source apportionment techniques: PMF factors resolved for submicron organic aerosols measured using aerosol mass spectrometry (AMS) by Xu et al. (2015a) in Centreville during SOAS; biomass burning organic aerosols (BBOA, 11% of OC), isoprene-derived organic aerosols (isoprene-OA, 20% of OC), more-oxidized oxygenated organic aerosols (MO-OOA, 34% of OC), and less-oxidized oxygenated organic aerosols (LO-OOA, 35% of OC); and PM_(2.5) OC apportioned by chemical-mass balance model (CMB), considering the same chemical species as this study, save for organosulfates; biomass burning (5%), diesel engines (2%), gasoline smokers (3%), vegetative detritus (1%), isoprene SOC (23%) and monoterpene SOC (34%), and other (likely biogenic secondary) sources (33%). Overall, this study indicates the primary and secondary sources resolved by the organic tracer-based PMF are in good agreement with CMB and AMS-PMF results, while the organic tracer-based PMF provides additional insight to the SOC formation pathways through the inclusion of organosulfates and other organic tracers measured during day and night