An Experimental Study of the Performance of a Subscale Kerosene - Fuelled Ejector Ramjet at Simulated Takeoff

The ejector ramjet is a rocket based combined cycle propulsion system in which a rocket and ramjet are integrated to accrue synergistic benefits. A proof-of-concept experiment to augment the thrust of a simulated rocket by the induction of air through an ejector and the subsequent afterburning of kerosene fuel in it is described. Ejector ram-jet thrust augmentation ratios of up to around 1.1 at the simulated take off conditions have been achieved. The critical effect of the operating conditions and the ejector ramjet geometry, in particular the afterburner configuration, for achieving thrust augmentation ratios greater than one have been demonstrated

The role of anion gap normalization time in the management of pediatric diabetic ketoacidosis

IntroductionOur aims were to determine whether anion gap normalization time (AGNT) correlates with risk factors related to the severity of diabetic ketoacidosis (DKA) in children, and to characterize AGNT as a criterion for DKA resolution in children admitted with moderate or severe disease.MethodsA ten-year retrospective cohort study of children admitted to the intensive care unit with DKA. We used a survival analysis approach to determine changes in serum glucose, bicarbonate, pH, and anion gap following admission. Using multivariate analysis, we examined associations between patients' demographic and laboratory characteristics with delayed normalization of the anion gap.ResultsA total of 95 patients were analyzed. The median AGNT was 8 h. Delayed AGNT (>8 h) correlated with pH < 7.1 and serum glucose >500 mg/dL. In multivariate analysis, glucose >500 mg/dL was associated with an increased risk for delayed AGNT, by 3.41 fold. Each 25 mg/dL elevation in glucose was associated with a 10% increment in risk for delayed AGNT. Median AGNT preceded median PICU discharge by 15 h (8 vs. 23 h).DiscussionAGNT represents a return to normal glucose-based physiology and an improvement in dehydration. The correlation observed between delayed AGNT and markers of DKA severity supports the usefulness of AGNT for assessing DKA recovery

Taking the Metabolic Pulse of the World\u27s Coral Reefs

Worldwide, coral reef ecosystems are experiencing increasing pressure from a variety of anthropogenic perturbations including ocean warming and acidification, increased sedimentation, eutrophication, and overfishing, which could shift reefs to a condition of net calcium carbonate (CaCO3) dissolution and erosion. Herein, we determine the net calcification potential and the relative balance of net organic carbon metabolism (net community production; NCP) and net inorganic carbon metabolism (net community calcification; NCC) within 23 coral reef locations across the globe. In light of these results, we consider the suitability of using these two metrics developed from total alkalinity (TA) and dissolved inorganic carbon (DIC) measurements collected on different spatiotemporal scales to monitor coral reef biogeochemistry under anthropogenic change. All reefs in this study were net calcifying for the majority of observations as inferred from alkalinity depletion relative to offshore, although occasional observations of net dissolution occurred at most locations. However, reefs with lower net calcification potential (i.e., lower TA depletion) could shift towards net dissolution sooner than reefs with a higher potential. The percent influence of organic carbon fluxes on total changes in dissolved inorganic carbon (DIC) (i.e., NCP compared to the sum of NCP and NCC) ranged from 32% to 88% and reflected inherent biogeochemical differences between reefs. Reefs with the largest relative percentage of NCP experienced the largest variability in seawater pH for a given change in DIC, which is directly related to the reefs ability to elevate or suppress local pH relative to the open ocean. This work highlights the value of measuring coral reef carbonate chemistry when evaluating their susceptibility to ongoing global environmental change and offers a baseline from which to guide future conservation efforts aimed at preserving these valuable ecosystems

Talek: Private Group Messaging with Hidden Access Patterns

Talek is a private group messaging system that sends messages through potentially untrustworthy servers, while hiding both data content and the communication patterns among its users. Talek explores a new point in the design space of private messaging; it guarantees access sequence indistinguishability, which is among the strongest guarantees in the space, while assuming an anytrust threat model, which is only slightly weaker than the strongest threat model currently found in related work. Our results suggest that this is a pragmatic point in the design space, since it supports strong privacy and good performance: we demonstrate a 3-server Talek cluster that achieves throughput of 9,433 messages/second for 32,000 active users with 1.7-second end-to-end latency. To achieve its security goals without coordination between clients, Talek relies on information-theoretic private information retrieval. To achieve good performance and minimize server-side storage, Talek intro- duces new techniques and optimizations that may be of independent interest, e.g., a novel use of blocked cuckoo hashing and support for private notifications. The latter provide a private, efficient mechanism for users to learn, without polling, which logs have new messages

Sepharadim/conversos and premodern Global Hispanism

Sepharadim participated in the Hispanic vernacular culture of the Iberian Peninsula. Even in the time of al-Andalus many spoke Hispano-Romance, and even their Hebrew literature belies a deep familiarity with and love of their native Hispano-Romance languages. However, since the early sixteenth century the vast majority of Sepharadim have never lived in the Hispanic world. Sepharadim lived not in Spanish colonies defined by Spanish conquest, but in a network of Mediterranean Jewish communities defined by diasporic values and institutions. By contrast, the conversos, those Sepharadim who converted to Catholicism, whether in Spain or later in Portugal, Italy, or the New World, lived mostly in Spanish Imperial lands, were officially Catholic, and spoke normative Castilian. Their connections, both real and imagined, with Sephardic cultural practice put them at risk of social marginalization, incarceration, even death. Some were devout Catholics whose heritage and family history doomed them to these outcomes. Not surprisingly, many Spanish and Portugese conversos sought refuge in lands outside of Spanish control where they might live openly as Jews. This exodus (1600s) from the lands formerly known as Sefarad led to a parallel Sephardic community of what conversos who re-embraced Judaism in Amsterdam and Italy by a generation of conversos trained in Spanish universities. The Sephardic/Converso cultural complex exceeds the boundaries of Spanish imperial geography, confuses Spanish, Portuguese, Catholic, and Jewish subjectivities, and defies traditional categories practiced in Hispanic studies, and are a unique example of the Global Hispanophone

Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.

BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden

An Experimental Investigation of a Four Inlet, Side Dump Combustor of a Kerosene - Fuelled Boosted Ramjet

An experimental investigation of a four-inlet side dump combustor configuration suitable for a boosted ramjet has been carried out. Combustor characteristics were obtained from water tunnel simulation and direct-connect combustion tests. A perspex, one third scale, model of the ramjet combustor was tested in a water rig. Flow field visualisation was accomplished by employing the hydrogen bubble streak technique. The best placement of the cruciform flameholder relative to the air inlet plane was determined. A similar combustor was made from stainless steel and tested in a combustor test rig. Combustion efficiency, cold and hot total pressure loss and ignition characteristics and lean blow-out limits were obtained. A design methodology for ramjet combustors has been arrived at

Interaction of Epe1 With the Heterochromatin Assembly Pathway in Schizosaccharomyces pombe

Epe1 is a JmjC domain protein that antagonizes heterochromatization in Schizosaccharomyces pombe. Related JmjC domain proteins catalyze a histone demethylation reaction that depends on Fe(II) and α-ketoglutarate. However, no detectable demethylase activity is associated with Epe1, and its JmjC domain lacks conservation of Fe(II)-binding residues. We report that Swi6 recruits Epe1 to heterochromatin and that overexpression of epe1(+), like mutations in silencing genes or overexpression of swi6(+), upregulates expression of certain genes. A significant overlap was observed between the lists of genes that are upregulated by overexpression of epe1(+) and those that are upregulated by mutations in histone deacetylase genes. However, most of the common genes are not regulated by Clr4 histone methyltransferase. This suggests that Epe1 interacts with the heterochromatin assembly pathway at the stage of histone deacetylation. Mutational inactivation of Epe1 downregulates ∼12% of S. pombe genes, and the list of these genes overlaps significantly with the lists of genes that are upregulated by mutations in silencing genes and genes that are hyperacetylated at their promoter regions in clr6-1 mutants. We propose that an interplay between the repressive HDACs activity and Epe1 helps to regulate gene expression in S. pombe

Human Metapneumovirus and Severity of Respiratory Syncytial Virus Disease

We screened 23 children with severe respiratory syncytial virus (RSV) disease and 23 children with mild RSV disease for human metapneumovirus (HMPV). Although HMPV was circulating in Connecticut, none of the 46 RSV-infected patients tested positive for HMPV. In our study population, HMPV did not contribute to the severity of RSV disease