The characterisation of liquid sprays injected from circular and non-circular nozzles into high speed subsonic cross-airstreams

This study was motivated by a need to better understand the sprays that can develop when oil leaks occur in gas turbine engines. Current gas turbine engines incorporate an extensive network of oil distribution pipes which deliver lubrication oil to bearings and seals at various locations across the engine. Parts of the oil pipe network are situated in hot, high pressure engine cavities where an oil leak, from a fractured pipe or leaking seal, could ignite and lead to an engine fire. Oil leaks in gas turbine engines create liquid injection in cross-airstream situations, a subject which has been widely studied for combustion systems. However, previous studies are almost exclusively based on circular nozzle geometries. For a fractured oil pipe, the geometry through which the oil leaks approximates to a slot shape rather than a circular nozzle. Sprays which develop in cross-airstreams are most sensitive to the parameters of Weber number (Weg eq) and momentum flux ratio (q). A wide range for these parameters are considered to be possible in engine oil leak scenarios because of the variety of crack dimensions possible and range of airflow conditions across the different sections of the engine; from zero to in excess of We g eq = 4000 and q = 300 could be possible in extreme cases. The aim of this study was to generate and then characterise sprays in representative conditions. The main focus was the characterisation of the droplets which formed in the sprays, with the key objective of providing validation data for CFD codes. Droplet characterisation was performed using a phase Doppler particle analysis system. High speed video as well as pulsed laser sheet digital imaging were also used in the study to provide insight into upstream features of the spray field. A 0.5 x 5.38 mm slot shaped nozzle geometry was used in two orientations; perpendicular alignment ↓↓⦶ and parallel alignment ↓↓⦶ . Water was injected into a cross-airstream over a twelve point test matrix with momentum flux ratios (q) values within the range of 4 ≳ q ≳ 32 and Weber number (We g eq) values within the range of 300 ≳ We g eq ≳ 1600. The position of the spray was highly dependent on slot nozzle orientation. The spray was considerably further offset from the nozzle injection wall in parallel alignment ↓↓⦶ , compared to the perpendicular alignment ↓↓⦶. However, the centre-line distribution of Arithmetic Mean Diameter (AMD) was similar for both orientations, albeit offset further from the injection wall for the parallel slot nozzle. The underlying structure of droplet size distribution was consistent with results for sprays from circular nozzles. At low liquid injection pressures the sprays produced by the perpendicular aligned slot ↓↓⦶ exhibited impingement, producing large droplets in the near wall region. Where impingement was not present, the data showed that AMD was not significantly influenced by the orientation of the slot nozzle; with all tests generating results in the range of 16 μm ≳ AMD ≳ 80 μm

UNH Digital Adventures 2020

A compilation of virtual activities to help educators engage their students in the online learning environment

Plasma microRNA levels following resection of metastatic melanoma

Melanoma remains the leading cause of skin cancer–related deaths. Surgical resection and adjuvant therapies can result in disease-free intervals for stage III and stage IV disease; however, recurrence is common. Understanding microRNA (miR) dynamics following surgical resection of melanomas is critical to accurately interpret miR changes suggestive of melanoma recurrence. Plasma of 6 patients with stage III (n = 2) and stage IV (n = 4) melanoma was evaluated using the NanoString platform to determine pre- and postsurgical miR expression profiles, enabling analysis of more than 800 miRs simultaneously in 12 samples. Principal component analysis detected underlying patterns of miR expression between pre- vs postsurgical patients. Group A contained 3 of 4 patients with stage IV disease (pre- and postsurgical samples) and 2 patients with stage III disease (postsurgical samples only). The corresponding preoperative samples to both individuals with stage III disease were contained in group B along with 1 individual with stage IV disease (pre- and postsurgical samples). Group A was distinguished from group B by statistically significant analysis of variance changes in miR expression ( P < .0001). This analysis revealed that group A vs group B had downregulation of let-7b-5p, miR-520f, miR-720, miR-4454, miR-21-5p, miR-22-3p, miR-151a-3p, miR-378e, and miR-1283 and upregulation of miR-126-3p, miR-223-3p, miR-451a, let-7a-5p, let-7g-5p, miR-15b-5p, miR-16-5p, miR-20a-5p, miR-20b-5p, miR-23a-3p, miR-26a-5p, miR-106a-5p, miR-17-5p, miR-130a-3p, miR-142-3p, miR-150-5p, miR-191-5p, miR-199a-3p, miR-199b-3p, and miR-1976. Changes in miR expression were not readily evident in individuals with distant metastatic disease (stage IV) as these individuals may have prolonged inflammatory responses. Thus, inflammatory-driven miRs coinciding with tumor-derived miRs can blunt anticipated changes in expression profiles following surgical resection

Barred Galaxies at z > 0.7: NICMOS HDFN Observations

Previous optical studies found an unexpected deficit of bars at z > 0.7. To investigate the effects of bandshifting, we have studied the fraction of barred spirals in the NICMOS Deep Field North. At z > 0.7 we find at least four barred spirals, doubling the number previously detected. The number of barred galaxies is small because these (and previous) data lack adequate spatial resolution. A typical 5 kpc bar at z > 0.7 is only marginally detectable for WFPC2 at 0.8microns; the NICMOS data have even lower resolution and can only find the largest bars. The average size of the four bars seen at z > 0.7 is 12 kpc. The fraction of such large bars (4/95) is higher than that seen in nearby spirals (1/44); all known selection effects suggest that the observed fraction is a lower limit. However, important caveats such as small numbers and difficulties in defining comparable samples at high and low redshifts should be noted. We conclude that there is no significant evidence for a decrease in the fraction of barred spirals beyond z ~ 0.7.Comment: Accepted for publication in ApJ Letters, 4 pages in emulate-apj style, includes 3 figure

Systematic comparison of ranking aggregation methods for gene lists in experimental results

MOTIVATION: A common experimental output in biomedical science is a list of genes implicated in a given biological process or disease. The gene lists resulting from a group of studies answering the same, or similar, questions can be combined by ranking aggregation methods to find a consensus or a more reliable answer. Evaluating a ranking aggregation method on a specific type of data before using it is required to support the reliability since the property of a dataset can influence the performance of an algorithm. Such evaluation on gene lists is usually based on a simulated database because of the lack of a known truth for real data. However, simulated datasets tend to be too small compared to experimental data and neglect key features, including heterogeneity of quality, relevance and the inclusion of unranked lists. RESULTS: In this study, a group of existing methods and their variations that are suitable for meta-analysis of gene lists are compared using simulated and real data. Simulated data were used to explore the performance of the aggregation methods as a function of emulating the common scenarios of real genomic data, with various heterogeneity of quality, noise level and a mix of unranked and ranked data using 20 000 possible entities. In addition to the evaluation with simulated data, a comparison using real genomic data on the SARS-CoV-2 virus, cancer (non-small cell lung cancer) and bacteria (macrophage apoptosis) was performed. We summarize the results of our evaluation in a simple flowchart to select a ranking aggregation method, and in an automated implementation using the meta-analysis by information content algorithm to infer heterogeneity of data quality across input datasets. AVAILABILITY AND IMPLEMENTATION: The code for simulated data generation and running edited version of algorithms: https://github.com/baillielab/comparison_of_RA_methods. Code to perform an optimal selection of methods based on the results of this review, using the MAIC algorithm to infer the characteristics of an input dataset, can be downloaded here: https://github.com/baillielab/maic. An online service for running MAIC: https://baillielab.net/maic. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online

Seasonal trivalent influenza vaccination during pregnancy and the incidence of stillbirth: population-based retrospective cohort study

Concern for the safety to the fetus is a commonly cited reason for vaccine refusal during pregnancy. Results from this investigation support the safety of seasonal influenza vaccination during pregnancy and suggest seasonal influenza vaccination may be protective against stillbirth

A genome-wide CRISPR/Cas9 screen reveals the requirement of host sphingomyelin synthase 1 for infection with Pseudorabies virus mutant gD–Pass

Herpesviruses are large DNA viruses, which encode up to 300 different proteins including enzymes enabling efficient replication. Nevertheless, they depend on a multitude of host cell proteins for successful propagation. To uncover cellular host factors important for replication of pseudorabies virus (PrV), an alphaherpesvirus of swine, we performed an unbiased genome-wide CRISPR/Cas9 forward screen. To this end, a porcine CRISPR-knockout sgRNA library (SsCRISPRko.v1) targeting 20,598 genes was generated and used to transduce porcine kidney cells. Cells were then infected with either wildtype PrV (PrV-Ka) or a PrV mutant (PrV-gD–Pass) lacking the receptor-binding protein gD, which regained infectivity after serial passaging in cell culture. While no cells survived infection with PrV-Ka, resistant cell colonies were observed after infection with PrV-gD–Pass. In these cells, sphingomyelin synthase 1 (SMS1) was identified as the top hit candidate. Infection efficiency was reduced by up to 90% for PrV-gD–Pass in rabbit RK13-sgms1KO cells compared to wildtype cells accompanied by lower viral progeny titers. Exogenous expression of SMS1 partly reverted the entry defect of PrV-gD–Pass. In contrast, infectivity of PrV-Ka was reduced by 50% on the knockout cells, which could not be restored by exogenous expression of SMS1. These data suggest that SMS1 plays a pivotal role for PrV infection, when the gD-mediated entry pathway is blocked

Focal points revisited: team reasoning, the principle of insufficient reason and cognitive hierarchy theory

It is well-established that people can coordinate their behaviour on focal points in games with multiple equilibria, but it is not firmly established how. Much coordination game data might be explained by team reasoning, a departure from individualistic choice theory. However, a less exotic explanation is also available based on best-responding to uniform randomisation. We test these two accounts experimentally, using novel games which distinguish their predictions. The results are inconsistent with best-responding to randomisation but consistent with team reasoning as the modal behaviour, though there is also unexplained heterogeneity. Increasing the difficulty of the coordination tasks produces some behaviour suggestive of response to randomisation, but this is a minor feature of the data

Using multiple lines of evidence to assess the risk of ecosystem collapse

Effective ecosystem risk assessment relies on a conceptual understanding of ecosystem dynamics and the synthesis of multiple lines of evidence. Risk assessment protocols and ecosystem models integrate limited observational data with threat scenarios, making them valuable tools for monitoring ecosystem status and diagnosing key mechanisms of decline to be addressed by management. We applied the IUCN Red List of Ecosystems criteria to quantify the risk of collapse of the Meso-American Reef, a unique ecosystem containing the second longest barrier reef in the world. We collated a wide array of empirical data (field and remotely sensed), and used a stochastic ecosystem model to backcast past ecosystem dynamics, as well as forecast future ecosystem dynamics under 11 scenarios of threat. The ecosystem is at high risk from mass bleaching in the coming decades, with compounding effects of ocean acidification, hurricanes, pollution and fishing. The overall status of the ecosystem is Critically Endangered (plausibly Vulnerable to Critically Endangered), with notable differences among Red List criteria and data types in detecting the most severe symptoms of risk. Our case study provides a template for assessing risks to coral reefs and for further application of ecosystem models in risk assessment.This work was supported by the Australian Research Council LP 130100435 and a Veski Inspiring Women Fellowship to E.N