The long period eccentric orbit of the particle accelerator HD167971 revealed by long baseline interferometry

Using optical long baseline interferometry, we resolved for the first time the two wide components of HD167971, a candidate hierarchical triple system known to efficiently accelerate particles. Our multi-epoch VLTI observations provide direct evidence for a gravitational link between the O8 supergiant and the close eclipsing O + O binary. The separation varies from 8 to 15 mas over the three-year baseline of our observations, suggesting that the components evolve on a wide and very eccentric orbit (most probably e>0.5). These results provide evidence that the wide orbit revealed by our study is not coplanar with the orbit of the inner eclipsing binary. From our measurements of the near-infrared luminosity ratio, we constrain the spectral classification of the components in the close binary to be O6-O7, and confirm that these stars are likely main-sequence objects. Our results are discussed in the context of the bright non-thermal radio emission already reported for this system, and we provide arguments in favour of a maximum radio emission coincident with periastron passage. HD167971 turns out to be an efficient O-type particle accelerator that constitutes a valuable target for future high angular resolution radio imaging using VLBI facilities.Comment: 8 pages, including 4 figures, accepted by Monthly Notices of the Royal Astronomical Societ

Flow-directed PCA for monitoring networks

Measurements recorded over monitoring networks often possess spatial and temporal correlation inducing redundancies in the information provided. For river water quality monitoring in particular, flow-connected sites may likely provide similar information. This paper proposes a novel approach to principal components analysis to investigate reducing dimensionality for spatiotemporal flow-connected network data in order to identify common spatiotemporal patterns. The method is illustrated using monthly observations of total oxidized nitrogen for the Trent catchment area in England. Common patterns are revealed that are hidden when the river network structure and temporal correlation are not accounted for. Such patterns provide valuable information for the design of future sampling strategies

Educating the educators: Incorporating bioinformatics into biological science education in Malaysia

Bioinformatics can be defined as a fusion of computational and biological sciences. The urgency to process and analyse the deluge of data created by proteomics and genomics studies has caused bioinformatics to gain prominence and importance. However, its multidisciplinary nature has created a unique demand for specialist trained in both biology and computing. In this review, we described the components that constitute the bioinformatics field and distinctive education criteria that are required to produce individuals with bioinformatics training. This paper will also provide an introduction and overview of bioinformatics in Malaysia. The existing bioinformatics scenario in Malaysia was surveyed to gauge its advancement and to plan for future bioinformatics education strategies. For comparison, we surveyed methods and strategies used in education by other countries so that lessons can be learnt to further improve the implementation of bioinformatics in Malaysia. It is believed that accurate and sufficient steerage from the academia and industry will enable Malaysia to produce quality bioinformaticians in the future

Systems biology in inflammatory bowel diseases

Purpose of review: Ulcerative colitis (UC) and Crohn’s Disease (CD) are the two predominant types of inflammatory bowel disease (IBD), affecting over 1.4 million individuals in the US. IBD results from complex interactions between pathogenic components, including genetic and epigenetic factors, the immune response and the microbiome through an unknown sequence of events. The purpose of this review is to describe a system biology approach to IBD as a novel and exciting methodology aiming at developing novel IBD therapeutics based on the integration of molecular and cellular "omics" data. Recent Findings: Recent evidence suggested the presence of genetic, epigenetic, transcriptomic, proteomic and metabolomic alterations in IBD patients. Furthermore, several studies have shown that different cell types, including fibroblasts, epithelial, immune and endothelial cells together with the intestinal microbiota are involved in IBD pathogenesis. Novel computational methodologies have been developed aiming to integrate high - throughput molecular data. Summary: A systems biology approach could potentially identify the central regulators (hubs) in the IBD interactome and improve our understanding of the molecular mechanisms involved in IBD pathogenesis. The future IBD therapeutics should be developed on the basis of targeting the central hubs in the IBD network

Enabling Premixed Hydrogen-Air Combustion for Aeroengines via Laboratory Experiment Modeling

All combustion systems from large scale power plants to the engines of cars to gas turbines in aircraft are looking for new fuel sources. Recently, clean energy for aviation has come into the foreground as an important issue due to the environment impacts of current combustion methods and fuels used. The aircraft industry is looking towards hydrogen as a new, powerful, and clean fuel of the future. However there are several engineering and scientific challenges to overcome before hydrogen can be deployed into the industry. These issuesrange from storing the hydrogen in a viable cryogenic form for an aircraft to stably burning the hydrogen in different phases during flight. Since a fundamental aspect, the fuel source (usually kerosene), is being switched to hydrogen, extensive modeling and ground testing of a future engine is required before a gas turbine engine can be retrofitted to work with hydrogen or built from the ground up. Modeling and simulating turbofan engine components can complement the engineering design process by allowing designs to be tested before beingimplemented into an actual turbofan engine. This allows an engineer to build confidence around a given design. Actual testing of gas turbine engines and their turbomachinery components is expensive and modeling these devices can help mitigate some of the cost and reduce potentially fatal errors in the design of the engine. In this thesis, several models are developed that allow for the study of hydrogen in a laboratory environment, and are compared to past works, industry software and data. This includes a 0D turbofan engine model and computational fluid dynamics simulations of a laboratory scale burner. The results formed in this work establish that the initial design of the burner and codes developedhere can serve as a foundation for future experiments and aid in the pursuit of achieving agas turbine engine operating with hydrogen-air mixtures

FLASHING: New high-velocity H2_2O masers in IRAS 18286−-0959

We discovered new high-velocity components of H$_2$O maser emission in one of the "water fountain" sources, IRAS~18286$-$0959, which has been monitored using the Nobeyama 45 m telescope in the new FLASHING (Finest Legacy Acquisitions of SiO- and H$_2$O-maser Ignitions by Nobeyama Generation) project since 2018 December. The maser spectra show new, extremely high expansion velocities ($>$200~km~s$^{-1}$ projected in the line of sight) components, some of which are located symmetrically in the spectrum with respect to the systemic velocity. They were also mapped with KaVA (KVN and VERA Combined Array) in 2019 March. We located some of these maser components closer to the central stellar system than other high velocity components (50--200~km~s$^{-1}$) that have been confirmed to be associated with the known bipolar outflow. The new components would flash in the fast collimated jet at a speed over 300~km~s$^{-1}$ (soon) after 2011 when they had not been detected. The fastest of the new components seem to indicate rapid deceleration in these spectra, however our present monitoring is still too sparse to unambiguously confirm it (up to 50~km~s$^{-1}$yr$^{-1}$) and too short to reveal their terminal expansion velocity, which will be equal to the expansion velocity that has been observed ($v_{\rm exp}\sim$120~km~s$^{-1}$). Future occurrences of such extreme velocity components may provide a good opportunity to investigate possible recurrent outflow ignitions. Thus sculpture of the parental envelope will be traced by the dense gas that is entrained by the fast jet and exhibits spectacular distributions of the relatively stable maser features.Comment: 11 pages, 5 figures, 2 table

Protein changes as robust signatures of fish chronic stress: a proteomics approach to fish welfare research

Background Aquaculture is a fast-growing industry and therefore welfare and environmental impact have become of utmost importance. Preventing stress associated to common aquaculture practices and optimizing the fish stress response by quantification of the stress level, are important steps towards the improvement of welfare standards. Stress is characterized by a cascade of physiological responses that, in-turn, induce further changes at the whole-animal level. These can either increase fitness or impair welfare. Nevertheless, monitorization of this dynamic process has, up until now, relied on indicators that are only a snapshot of the stress level experienced. Promising technological tools, such as proteomics, allow an unbiased approach for the discovery of potential biomarkers for stress monitoring. Within this scope, using Gilthead seabream (Sparus aurata) as a model, three chronic stress conditions, namely overcrowding, handling and hypoxia, were employed to evaluate the potential of the fish protein-based adaptations as reliable signatures of chronic stress, in contrast with the commonly used hormonal and metabolic indicators. Results A broad spectrum of biological variation regarding cortisol and glucose levels was observed, the values of which rose higher in net-handled fish. In this sense, a potential pattern of stressor-specificity was clear, as the level of response varied markedly between a persistent (crowding) and a repetitive stressor (handling). Gel-based proteomics analysis of the plasma proteome also revealed that net-handled fish had the highest number of differential proteins, compared to the other trials. Mass spectrometric analysis, followed by gene ontology enrichment and protein-protein interaction analyses, characterized those as humoral components of the innate immune system and key elements of the response to stimulus. Conclusions Overall, this study represents the first screening of more reliable signatures of physiological adaptation to chronic stress in fish, allowing the future development of novel biomarker models to monitor fish welfare.This study received Portuguese national funds from FCT - Foundation for Science and Technology through project UIDB/04326/2020 and project WELFISH (Refª 16–02-05-FMP-12, “Establishment of Welfare Biomarkers in farmed fish using a proteomics approach”) financed by Mar2020, in the framework of the program Portugal 2020. Cláudia Raposo de Magalhães acknowledges an FCT PhD scholarship, Refª SFRH/BD/138884/2018. Denise Schrama acknowledges an FCT PhD scholarship, Refª SFRH/BD/136319/2018.info:eu-repo/semantics/publishedVersio

Applications of Solid Freeform Fabrication at the Naval Research Laboratory

Solid Freeform Fabrication (SFF) and related techniques are used at the Naval Research Laboratory (NRL) for a variety of materials related investigations. Research and applications conducted over the past few years are described including: Helisys Laminated Object Manufacturing System (LOMS) fabrication of: ceramic piezoelectric actuators, tooling for multifunctional materials, and anatomical prototypes for surgical visualization; fabrication of mesoscale electronic and sensor components using a laser forward transfer direct write technique; and visualization of complex, 3-D microstructures using a Stratasys Fused-Deposition Modeler. The paper closes with a brief overview of future SFF related work at the NRL.Support for this work from DARPA, Office of Naval Research, and the Naval Research Laboratory Core Research Program is gratefully acknowledged.Mechanical Engineerin

Multi-parameter Tests of General Relativity Using Bayesian Parameter Estimation with Principal Component Analysis for LISA

In the near future, space-borne gravitational wave (GW) detector LISA can open the window of low-frequency band of GW and provide new tools to test gravity theories. In this work, we consider multi-parameter tests of GW generation and propagation where the deformation coefficients are varied simultaneously in parameter estimation and the principal component analysis (PCA) method are used to transform posterior samples into new bases for extracting the most informative components. The dominant components can be better mesured and constrained and are more sensitive to potential departures from general relativity (GR). We extend previous works by employing Bayesian parameter estimation and performing both null tests and tests with injections of subtle GR-violated signals. We also apply multi-parameter tests with PCA in the phenomenological test of GW propagation. This work complements previous works and further demonstrates the enhancement provided by the PCA method. Considering a supermassive black hole binary system as the GW source, we find that $1\sigma$ bounds of the most dominant PCA parameter can be one order of magnitude tighter than the bounds of original deformation parameter of leading frequency order. The departures less than $1\sigma$ in original parameters can yield significant departures in first 5 dominant PCA parameters.Comment: 16 pages, 6 figure

Squeezed between shells? On the origin of the Lupus I molecular cloud. - II. APEX CO and GASS HI observations

Accepted for publication in a future issue of Astronomy & Astrophysics. Reproduced with permission from Astronomy & Astrophysics. © 2018 ESO.Context. The Lupus I cloud is found between the Upper-Scorpius (USco) and the Upper-Centaurus-Lupus (UCL) sub-groups of the Scorpius-Centaurus OB-association, where the expanding USco H I shell appears to interact with a bubble currently driven by the winds of the remaining B-stars of UCL. Aims. We investigate if the Lupus I molecular could have formed in a colliding flow, and in particular, how the kinematics of the cloud might have been influenced by the larger scale gas dynamics. Methods. We performed APEX 13CO(2–1) and C 18O(2–1) line observations of three distinct parts of Lupus I that provide kinematic information on the cloud at high angular and spectral resolution. We compare those results to the atomic hydrogen data from the GASS H i survey and our dust emission results presented in the previous paper. Based on the velocity information, we present a geometric model for the interaction zone between the USco shell and the UCL wind bubble. Results. We present evidence that the molecular gas of Lupus I is tightly linked to the atomic material of the USco shell. The CO emission in Lupus I is found mainly at velocities between vLSR = 3–6 km s−1 which is in the same range as the H i velocities. Thus, the molecular cloud is co-moving with the expanding USco atomic H i shell. The gas in the cloud shows a complex kinematic structure with several line-of-sight components that overlay each other. The non-thermal velocity dispersion is in the transonic regime in all parts of the cloud and could be injected by external compression. Our observations and the derived geometric model agree with a scenario where Lupus I is located in the interaction zone between the USco shell and the UCL wind bubble. Conclusions. The kinematics observations are consistent with a scenario where the Lupus I cloud formed via shell instabilities. The particular location of Lupus I between USco and UCL suggests that counter-pressure from the UCL wind bubble and pre-existing density enhancements, perhaps left over from the gas stream that formed the stellar subgroups, may have played a role in its formation.Peer reviewedFinal Accepted Versio