1,603 research outputs found
Computational methods for metabolomic data analysis of ion mobility spectrometry data-reviewing the state of the art
Ion mobility spectrometry combined with multi-capillary columns (MCC/IMS) is a well known technology for detecting volatile organic compounds (VOCs). We may utilize MCC/IMS for scanning human exhaled air, bacterial colonies or cell lines, for example. Thereby we gain information about the human health status or infection threats. We may further study the metabolic response of living cells to external perturbations. The instrument is comparably cheap, robust and easy to use in every day practice. However, the potential of the MCC/IMS methodology depends on the successful application of computational approaches for analyzing the huge amount of emerging data sets. Here, we will review the state of the art and highlight existing challenges. First, we address methods for raw data handling, data storage and visualization. Afterwards we will introduce de-noising, peak picking and other pre-processing approaches. We will discuss statistical methods for analyzing correlations between peaks and diseases or medical treatment. Finally, we study up-to-date machine learning techniques for identifying robust biomarker molecules that allow classifying patients into healthy and diseased groups. We conclude that MCC/IMS coupled with sophisticated computational methods has the potential to successfully address a broad range of biomedical questions. While we can solve most of the data pre-processing steps satisfactorily, some computational challenges with statistical learning and model validation remain
Carrier-envelope phase effects on the strong-field photoemission of electrons from metallic nanostructures
Sharp metallic nanotapers irradiated with few-cycle laser pulses are emerging
as a source of highly confined coherent electron wavepackets with attosecond
duration and strong directivity. The possibility to steer, control or switch
such electron wavepackets by light is expected to pave the way towards direct
visualization of nanoplasmonic field dynamics and real-time probing of electron
motion in solid state nanostructures. Such pulses can be generated by
strong-field induced tunneling and acceleration of electrons in the near-field
of sharp gold tapers within one half-cycle of the driving laser field. Here, we
show the effect of the carrier-envelope phase of the laser field on the
generation and motion of strong-field emitted electrons from such tips. This is
a step forward towards controlling the coherent electron motion in and around
metallic nanostructures on ultrashort length and time scales
Insight into human alveolar macrophage and M. tuberculosis interactions via metabolic reconstructions
A human alveolar macrophage genome-scale metabolic reconstruction was reconstructed from tailoring a global human metabolic network, Recon 1, by using computational algorithms and manual curation.A genome-scale host–pathogen network of the human alveolar macrophage and Mycobacterium tuberculosis is presented. This involved integrating two genome-scale network reconstructions.The reaction activity and gene essentiality predictions of the host–pathogen model represent a more accurate depiction of infection.Integration of high-throughput data into a host-pathogen model followed by systems analysis was performed in order to elucidate major metabolic differences under different types of M. tuberculosis infection
Next generation of mascot nano-landers for the multiple neo rendezvous mission: A self-transferring lander for the ’Sousveillance' of NEOs for space exploration, planetary defence or resource utilisation
This is an exciting time for Near-Earth Object (NEO) Exploration as we get closer to finding answers to many important questions on how the Solar System was formed, how life arrived on Earth and how the vastly unknown Small Solar System Bodies (SSSBs) behave. In the next three years we will see the return of asteroid samples by the HAYABUSA2 and the OSIRIS-REx missions and the launch of the NEA SCOUT, PSYCHE, LUCY, DART and HERA missions. Yet the NEA classifications are not exhaustive and each new asteroid provides its unique challenges. Thus, an on-site study via nano-landers has multi-fold advantages as they can provide a detailed scientific analysis and can lay the foundation for In-situ Resource Utilisation (ISRU) missions by the selection and geo-spatial mapping of the target site and by the testing of the relevant technology demonstration. Until now nano-landers have been deployed from an altitude of 40-100 meters. This paper aims to exploit the high vantage point of small spacecraft technology to study micro-gravity bodies by proposing a self-transferring, highly integrated nano-lander that can be deployed at ten to hundred-fold higher altitudes than before. It is a successor of MASCOT - the DLR-CNES nano-lander aboard HAYABUSA2 that successfully operated on (162173) Ryugu in 2018. An exciting prospect for future MASCOTs is a Multiple-NEO Rendezvous (MNR) mission by a Solar-Sailing spacecraft. A previous GOSSAMER based study proves the feasibility of a ten-year mission that could deploy five MASCOTs to five asteroids in hundred days. This paper goes one step further and equips the nano-landers with minimalistic self-transfer GNC and Propulsion systems thereby enhancing the multiple target mission returns while conforming to the nano-spacecraft's system design constraints. Additionally, a software-in-the-loop mission design and a Monte Carlo sensitivity analysis have been done to prove its capability to land on the moon of binary asteroid systems that are critical target bodies for the development of planetary defence technology. The proposed MASCOT-variant can have a customised payload for individual target bodies. This system can hence pave way to a new generation of intelligent yet simple landers that can help in all the fields of NEO studies such as reconnaissance missions preceding human exploration or asteroid mining missions. Looking at how many extra miles a self-transfer MASCOT could scout ahead, the mission parameters are outlined for an added in-situ exploration capability which is simultaneously relaxing the requirements on and de-risking the operations of its main spacecraft
Searching for the Majority: Algorithms of Voluntary Control
Voluntary control of information processing is crucial to allocate resources and prioritize the processes that are most important under a given situation; the algorithms underlying such control, however, are often not clear. We investigated possible algorithms of control for the performance of the majority function, in which participants searched for and identified one of two alternative categories (left or right pointing arrows) as composing the majority in each stimulus set. We manipulated the amount (set size of 1, 3, and 5) and content (ratio of left and right pointing arrows within a set) of the inputs to test competing hypotheses regarding mental operations for information processing. Using a novel measure based on computational load, we found that reaction time was best predicted by a grouping search algorithm as compared to alternative algorithms (i.e., exhaustive or self-terminating search). The grouping search algorithm involves sampling and resampling of the inputs before a decision is reached. These findings highlight the importance of investigating the implications of voluntary control via algorithms of mental operations
Levodopa-induced myocardial infarction in a patient with Parkinson’s disease and severe coronary artery disease
Levodopa is the most effective medical treatment for Parkinson’s disease (PD) to date. As dopamine is known to increase cardiac inotropism and vasomotor tone, peripheral dopamine decarboxylase inhibitor is coadministered to suppress the peripheral conversion of levodopa to dopamine. Levodopa poses potential cardiovascular risks, thus its use in patients with existing coronary artery disease needs to be carefully monitored. We report a case of an elderly male with newly diagnosed PD who developed non-ST-elevation myocardial infarction following levodopa (Madopar) initiation
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