318 research outputs found
A few-shot graph Laplacian-based approach for improving the accuracy of low-fidelity data
Low-fidelity data is typically inexpensive to generate but inaccurate. On the
other hand, high-fidelity data is accurate but expensive to obtain.
Multi-fidelity methods use a small set of high-fidelity data to enhance the
accuracy of a large set of low-fidelity data. In the approach described in this
paper, this is accomplished by constructing a graph Laplacian using the
low-fidelity data and computing its low-lying spectrum. This spectrum is then
used to cluster the data and identify points that are closest to the centroids
of the clusters. High-fidelity data is then acquired for these key points.
Thereafter, a transformation that maps every low-fidelity data point to its
bi-fidelity counterpart is determined by minimizing the discrepancy between the
bi- and high-fidelity data at the key points, and to preserve the underlying
structure of the low-fidelity data distribution. The latter objective is
achieved by relying, once again, on the spectral properties of the graph
Laplacian. This method is applied to a problem in solid mechanics and another
in aerodynamics. In both cases, this methods uses a small fraction of
high-fidelity data to significantly improve the accuracy of a large set of
low-fidelity data
Simultaneous fNIRS and thermal infrared imaging during cognitive task reveal autonomic correlates of prefrontal cortex activity
Functional Near Infrared-Spectroscopy (fNIRS) represents a powerful tool to non-invasively study task-evoked brain activity. fNIRS assessment of cortical activity may suffer for contamination by physiological noises of different origin (e.g. heart beat, respiration, blood pressure, skin blood flow), both task-evoked and spontaneous. Spontaneous changes occur at different time scales and, even if they are not directly elicited by tasks, their amplitude may result task-modulated. In this study, concentration changes of hemoglobin were recorded over the prefrontal cortex while simultaneously recording the facial temperature variations of the participants through functional infrared thermal (fIR) imaging. fIR imaging provides touch-less estimation of the thermal expression of peripheral autonomic. Wavelet analysis revealed task-modulation of the very low frequency (VLF) components of both fNIRS and fIR signals and strong coherence between them. Our results indicate that subjective cognitive and autonomic activities are intimately linked and that the VLF component of the fNIRS signal is affected by the autonomic activity elicited by the cognitive task. Moreover, we showed that task-modulated changes in vascular tone occur both at a superficial and at larger depth in the brain. Combined use of fNIRS and fIR imaging can effectively quantify the impact of VLF autonomic activity on the fNIRS signals
Theoretical principles of formation of financial control at the enterprise
У роботі представлено теоретичні основи фінансового контролінгу у системі фінансового менеджменту
підприємства. Метою дослідження є висвітлення теоретичних основ фінансового контролінгу на підприємстві,
визначення ролі та місця фінансового контролінгу у системі фінансового менеджменту, виявлення основних факторів,
що здійснюють вплив на формування фінансового контролінгу на підприємстві Надано визначення терміну «контролінг»
як механізму управління підприємствами з метою підвищення прибутку. Обґрунтовано актуальність цього інструменту
управління, що дозволяє компанії надійно орієнтуватися в ринкових відносинах, чого не забезпечували раніше застосовувані
системи планування та обліку. У статті наведено еволюцію основних етапів формування концепції системного
управління на основі впровадження контролінгу на підприємстві. Висвітлено основні фактори, що можуть впливати
на ефективність реалізації управління підприємством. Представлено чинники, які здійснюють вплив на впровадження
контролінгу на підприємстві.The paper presents the theoretical foundations of the formation of controlling at the enterprise. The definition of the
term "controlling" as a mechanism of enterprise management in order to increase profit is provided. The work uses such methods
as: analysis and evaluation, comparison, indexation and deduction, graphic method. The relevance of this management tool is
determined, which allows the company to reliably navigate market relations compared to the previously available planning and
accounting systems. The existing variety of definitions and views suggests that controlling is a dynamic field that develops in the
direction of the theory and practice of organization management. It was established that during the practical implementation of the
management system and its tools, a number of factors may arise that can lead to the effective implementation of the management
system. It was noted that the constant development of economic relations and socio-economic systems also determines the
development of approaches to understanding the company's effectiveness. The article describes the evolution of the main stages of
the formation of the concept of system management based on the implementation of controlling at the enterprise. The main factors
that can affect the effectiveness of the implementation of enterprise management are given. The factors influencing the formation
of the strategy for the implementation of controlling at the enterprise are presented. The practical significance of this article lies in
the fact that the implementation of a modern concept of financial management based on controlling can help the enterprise achieve
the tasks and goals set by it, ensure compliance with the formed strategies and determines the effectiveness of operational and
tactical plans for enterprise management
Place of financial controlling in the financial management of industrial enterprises
У статті розглянуто проблеми, пов’язані із впровадженням та розвитком фінансового контролінгу як функції фінансового менеджменту промислових підприємств. Проаналізовано та конкретизовано проблеми фінансового менеджменту і контролінгу на українських промислових підприємствах в сучасних умовах. Визначено роль і місце фінансового контролінгу в системі фінансового менеджменту підприємства. На підставі аналізу проблем фінансового менеджменту та контролінгу доведено, що фінансовий контролінг є найбільш раціональним способом досягнення ефективної діяльності промислового підприємства. Обґрунтовано необхідність застосування та удосконалення окремих специфічних методів та інструментів фінансового контролінгу на промислових підприємствах.В статье рассмотрены проблемы, связанные с внедрением и развитием финансового контроллинга как функции финансового менеджмента промышленных предприятий. Проанализированы и конкретизированы проблемы финансового менеджмента и контроллинга на украинских промышленных предприятиях в современных условиях. Определены роль и место финансового контроллинга в системе финансового менеджмента предприятия. На основании анализа проблем финансового менеджмента и контроллинга доказано, что финансовый контроллинг является наиболее рациональным способом достижения эффективной деятельности промышленного предприятия. Обоснована необходимость применения и усовершенствования отдельных специфических методов и инструментов контроллинга на промышленных предприятиях.The article deals with the problems associated with the introduction and development of financial controlling as the financial management function of industrial enterprises. It analyzes and concretizes specific problems of financial management and controlling of Ukrainian industrial enterprises in the modern conditions. The role and place of financial controlling in the system of financial management of the company are identified. It is proved that financial controlling is the most rational way to achieve efficient operation of the industrial enterprises based on the analysis of problems of financial management and controlling. The necessity of usage and improvement of different specific methods and tools of controlling at industrial enterprises is substantiated
Wearables and the brain
The brain is the last frontier for wearable sensing. Commercially available wearables can monitor your vital signs and physical activity, but few have the ability to monitor what goes on inside your head. With the advent of new wearable and portable neuroimaging technologies, this situation might be about to change, with profound implications for neuroscience and for wearables
Mitochondrial DNA and exercise: Implications for health and injuries in sports
Recently, several studies have highlighted the tight connection between mitochondria and physical activity. Mitochondrial functions are important in high-demanding metabolic activities, such as endurance sports. Moreover, regular training positively affects metabolic health by increasing mitochondrial oxidative capacity and regulating glucose metabolism. Exercise could have multiple effects, also on the mitochondrial DNA (mtDNA) and vice versa; some studies have investigated how mtDNA polymorphisms can affect the performance of general athletes and mtDNA haplogroups seem to be related to the performance of elite endurance athletes. Along with several stimuli, including pathogens, stress, trauma, and reactive oxygen species, acute and intense exercise also seem to be responsible for mtDNA release into the cytoplasm and extracellular space, leading to the activation of the innate immune response. In addition, several sports are characterized by a higher frequency of injuries, including cranial trauma, associated with neurological consequences. However, with regular exercise, circulating cell-free mtDNA levels are kept low, perhaps promoting cf-mtDNA removal, acting as a protective factor against inflammation
Molecular mechanisms of mtdna-mediated inflammation
Besides their role in cell metabolism, mitochondria display many other functions. Mitochondrial DNA (mtDNA), the own genome of the organelle, plays an important role in modulating the inflammatory immune response. When released from the mitochondrion to the cytosol, mtDNA is recognized by cGAS, a cGAMP which activates a pathway leading to enhanced expression of type I interferons, and by NLRP3 inflammasome, which promotes the activation of pro-inflammatory cytokines Interleukin-1beta and Interleukin-18. Furthermore, mtDNA can be bound by Toll-like receptor 9 in the endosome and activate a pathway that ultimately leads to the expression of pro-inflammatory cytokines. mtDNA is released in the extracellular space in different forms (free DNA, protein-bound DNA fragments) either as free circulating molecules or encapsulated in extracellular vesicles. In this review, we discussed the latest findings concerning the molecular mechanisms that regulate the release of mtDNA from mitochondria, and the mechanisms that connect mtDNA misplacement to the activation of inflammation in different pathophysiological conditions
Synthesis and anticancer activity of CDDO and CDDO-me, two derivatives of natural triterpenoids
Triterpenoids are natural compounds synthesized by plants through cyclization of squalene, known for their weak anti-inflammatory activity. 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO), and its C28 modified derivative, methyl-ester (CDDO-Me, also known as bardoxolone methyl), are two synthetic derivatives of oleanolic acid, synthesized more than 20 years ago, in an attempt to enhance the anti-inflammatory behavior of the natural compound. These molecules have been extensively investigated for their strong ability to exert antiproliferative, antiangiogenic, and antimetastatic activities, and to induce apoptosis and differentiation in cancer cells. Here, we discuss the chemical properties of natural triterpenoids, the pathways of synthesis and the biological effects of CDDO and its derivative CDDO-Me. At nanomolar doses, CDDO and CDDO-Me have been shown to protect cells and tissues from oxidative stress by increasing the transcriptional activity of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2). At doses higher than 100 nM, CDDO and CDDO-Me are able to modulate the differentiation of a variety of cell types, both tumor cell lines or primary culture cell, while at micromolar doses these compounds exert an anticancer effect in multiple manners; by inducing extrinsic or intrinsic apoptotic pathways, or autophagic cell death, by inhibiting telomerase activity, by disrupting mitochondrial functions through Lon protease inhibition, and by blocking the deubiquitylating enzyme USP7. CDDO-Me demonstrated its efficacy as anticancer drugs in different mouse models, and versus several types of cancer. Several clinical trials have been started in humans for evaluating CDDO-Me efficacy as anticancer and anti-inflammatory drug; despite promising results, significant increase in heart failure events represented an obstacle for the clinical use of CDDO-Me
Using fiberless, wearable fNIRS to monitor brain activity in real-world cognitive tasks
Functional Near Infrared Spectroscopy (fNIRS) is a neuroimaging technique that uses near-infrared light to monitor brain activity. Based on neurovascular coupling, fNIRS is able to measure the haemoglobin concentration changes secondary to neuronal activity. Compared to other neuroimaging techniques, fNIRS represents a good compromise in terms of spatial and temporal resolution. Moreover, it is portable, lightweight, less sensitive to motion artifacts and does not impose significant physical restraints. It is therefore appropriate to monitor a wide range of cognitive tasks (e.g., auditory, gait analysis, social interaction) and different age populations (e.g., new-borns, adults, elderly people). The recent development of fiberless fNIRS devices has opened the way to new applications in neuroscience research. This represents a unique opportunity to study functional activity during real-world tests, which can be more sensitive and accurate in assessing cognitive function and dysfunction than lab-based tests. This study explored the use of fiberless fNIRS to monitor brain activity during a real-world prospective memory task. This protocol is performed outside the lab and brain haemoglobin concentration changes are continuously measured over the prefrontal cortex while the subject walks around in order to accomplish several different tasks
A novel GLM-based method for the Automatic IDentification of functional Events (AIDE) in fNIRS data recorded in naturalistic environments.
Recent technological advances have allowed the development of portable functional Near-Infrared Spectroscopy (fNIRS) devices that can be used to perform neuroimaging in the real-world. However, as real-world experiments are designed to mimic everyday life situations, the identification of event onsets can be extremely challenging and time-consuming. Here, we present a novel analysis method based on the general linear model (GLM) least square fit analysis for the Automatic IDentification of functional Events (or AIDE) directly from real-world fNIRS neuroimaging data. In order to investigate the accuracy and feasibility of this method, as a proof-of-principle we applied the algorithm to (i) synthetic fNIRS data simulating both block-, event-related and mixed-design experiments and (ii) experimental fNIRS data recorded during a conventional lab-based task (involving maths). AIDE was able to recover functional events from simulated fNIRS data with an accuracy of 89%, 97% and 91% for the simulated block-, event-related and mixed-design experiments respectively. For the lab-based experiment, AIDE recovered more than the 66.7% of the functional events from the fNIRS experimental measured data. To illustrate the strength of this method, we then applied AIDE to fNIRS data recorded by a wearable system on one participant during a complex real-world prospective memory experiment conducted outside the lab. As part of the experiment, there were four and six events (actions where participants had to interact with a target) for the two different conditions respectively (condition 1: social-interact with a person; condition 2: non-social-interact with an object). AIDE managed to recover 3/4 events and 3/6 events for conditions 1 and 2 respectively. The identified functional events were then corresponded to behavioural data from the video recordings of the movements and actions of the participant. Our results suggest that "brain-first" rather than "behaviour-first" analysis is possible and that the present method can provide a novel solution to analyse real-world fNIRS data, filling the gap between real-life testing and functional neuroimaging
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