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1.
Heliyon ; 10(7): e28562, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38576546

RESUMEN

As artificial intelligence systems gain traction, their trustworthiness becomes paramount to harness their benefits and mitigate risks. This study underscores the pressing need for an expectation management framework to align stakeholder anticipations before any system-related activities, such as data collection, modeling, or implementation. To this end, we introduce a comprehensive framework tailored to capture end-user expectations specifically for trustworthy artificial intelligence systems. To ensure its relevance and robustness, we validated the framework via semi-structured interviews, encompassing questions rooted in the framework's constructs and principles. These interviews engaged fourteen diverse end users across the healthcare and education sectors, including physicians, teachers, and students. Through a meticulous qualitative analysis of the interview transcripts, we unearthed pivotal themes and discerned varying perspectives among the interviewee groups. Ultimately, our framework stands as a pivotal tool, paving the way for in-depth discussions about user expectations, illuminating the significance of various system attributes, and spotlighting potential challenges that might jeopardize the system's efficacy.

2.
Neurosurg Clin N Am ; 34(2): 269-283, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36906333

RESUMEN

Magnetic hyperthermia therapy (MHT) is a highly localized form of hyperthermia therapy (HT) that has been effective in treating various forms of cancer. Many clinical and preclinical studies have applied MHT to treat aggressive forms of brain cancer and assessed its role as a potential adjuvant to current therapies. Initial results show that MHT has a strong antitumor effect in animal studies and a positive association with overall survival in human glioma patients. Although MHT is a promising therapy with the potential to be incorporated into the future treatment of brain cancer, significant advancement of current MHT technology is required.


Asunto(s)
Neoplasias Encefálicas , Glioma , Hipertermia Inducida , Animales , Humanos , Hipertermia Inducida/métodos , Glioma/terapia , Neoplasias Encefálicas/terapia , Fenómenos Magnéticos
3.
Hum Brain Mapp ; 41(8): 2059-2076, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-31977145

RESUMEN

Epileptic seizure detection and prediction by using noninvasive measurements such as scalp EEG signals or invasive, intracranial recordings, has been at the heart of epilepsy studies for at least three decades. To this end, the most common approach has been to consider short-length recordings (several seconds to a few minutes) around a seizure, aiming to identify significant changes that occur before or during seizures. An inherent assumption in this approach is the presence of a relatively constant EEG activity in the interictal period, which is interrupted by seizure occurrence. Here, we examine this assumption by using long-duration scalp EEG data (21-94 hr) in nine patients with epilepsy, based on which we construct functional brain networks. Our results reveal that these networks vary over time in a periodic fashion, exhibiting multiple peaks at periods ranging between 1 and 24 hr. The effects of seizure onset on the functional brain network properties were found to be considerably smaller in magnitude compared to the changes due to these inherent periodic cycles. Importantly, the properties of the identified network periodic components (instantaneous phase) were found to be strongly correlated to seizure onset, especially for the periodicities around 3 and 5 hr. These correlations were found to be largely absent between EEG signal periodicities and seizure onset, suggesting that higher specificity may be achieved by using network-based metrics. In turn, this implies that more robust seizure detection and prediction can be achieved if longer term underlying functional brain network periodic variations are taken into account.


Asunto(s)
Corteza Cerebral/fisiopatología , Conectoma , Electroencefalografía , Epilepsia/diagnóstico , Epilepsia/fisiopatología , Red Nerviosa/fisiopatología , Adulto , Corteza Cerebral/diagnóstico por imagen , Niño , Femenino , Humanos , Masculino , Red Nerviosa/diagnóstico por imagen , Periodicidad , Factores de Tiempo
4.
Front Neurosci ; 13: 221, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30949021

RESUMEN

It is well-established that both volume conduction and the choice of recording reference (montage) affect the correlation measures obtained from scalp EEG, both in the time and frequency domains. As a result, a number of correlation measures have been proposed aiming to reduce these effects. In our previous work, we have showed that scalp-EEG based functional brain networks in patients with epilepsy exhibit clear periodic patterns at different time scales and that these patterns are strongly correlated to seizure onset, particularly at shorter time scales (around 3 and 5 h), which has important clinical implications. In the present work, we use the same long-duration clinical scalp EEG data (multiple days) to investigate the extent to which the aforementioned results are affected by the choice of reference choice and correlation measure, by considering several widely used montages as well as correlation metrics that are differentially sensitive to the effects of volume conduction. Specifically, we compare two standard and commonly used linear correlation measures, cross-correlation in the time domain, and coherence in the frequency domain, with measures that account for zero-lag correlations: corrected cross-correlation, imaginary coherence, phase lag index, and weighted phase lag index. We show that the graphs constructed with corrected cross-correlation and WPLI are more stable across different choices of reference. Also, we demonstrate that all the examined correlation measures revealed similar periodic patterns in the obtained graph measures when the bipolar and common reference (Cz) montage were used. This includes circadian-related periodicities (e.g., a clear increase in connectivity during sleep periods as compared to awake periods), as well as periodicities at shorter time scales (around 3 and 5 h). On the other hand, these results were affected to a large degree when the average reference montage was used in combination with standard cross-correlation, coherence, imaginary coherence, and PLI, which is likely due to the low number of electrodes and inadequate electrode coverage of the scalp. Finally, we demonstrate that the correlation between seizure onset and the brain network periodicities is preserved when corrected cross-correlation and WPLI were used for all the examined montages. This suggests that, even in the standard clinical setting of EEG recording in epilepsy where only a limited number of scalp EEG measurements are available, graph-theoretic quantification of periodic patterns using appropriate montage, and correlation measures corrected for volume conduction provides useful insights into seizure onset.

5.
Clin Neurophysiol ; 128(9): 1755-1769, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28778057

RESUMEN

OBJECTIVE: This paper proposes supervised and unsupervised algorithms for automatic muscle artifact detection and removal from long-term EEG recordings, which combine canonical correlation analysis (CCA) and wavelets with random forests (RF). METHODS: The proposed algorithms first perform CCA and continuous wavelet transform of the canonical components to generate a number of features which include component autocorrelation values and wavelet coefficient magnitude values. A subset of the most important features is subsequently selected using RF and labelled observations (supervised case) or synthetic data constructed from the original observations (unsupervised case). The proposed algorithms are evaluated using realistic simulation data as well as 30min epochs of non-invasive EEG recordings obtained from ten patients with epilepsy. RESULTS: We assessed the performance of the proposed algorithms using classification performance and goodness-of-fit values for noisy and noise-free signal windows. In the simulation study, where the ground truth was known, the proposed algorithms yielded almost perfect performance. In the case of experimental data, where expert marking was performed, the results suggest that both the supervised and unsupervised algorithm versions were able to remove artifacts without affecting noise-free channels considerably, outperforming standard CCA, independent component analysis (ICA) and Lagged Auto-Mutual Information Clustering (LAMIC). CONCLUSION: The proposed algorithms achieved excellent performance for both simulation and experimental data. Importantly, for the first time to our knowledge, we were able to perform entirely unsupervised artifact removal, i.e. without using already marked noisy data segments, achieving performance that is comparable to the supervised case. SIGNIFICANCE: Overall, the results suggest that the proposed algorithms yield significant future potential for improving EEG signal quality in research or clinical settings without the need for marking by expert neurophysiologists, EMG signal recording and user visual inspection.


Asunto(s)
Algoritmos , Artefactos , Electroencefalografía/métodos , Cuero Cabelludo/fisiología , Análisis de Ondículas , Electroencefalografía/normas , Humanos , Distribución Aleatoria
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2016: 2822-2825, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28268905

RESUMEN

We investigated the correlation of epileptic seizure onset times with long term EEG functional brain network properties. To do so, we constructed binary functional brain networks from long-term, multichannel electroencephalographic data recorded from nine patients with epilepsy. The corresponding network properties were quantified using the average network degree. It was found that the network degree (as well as other network properties such as the network efficiency and clustering coefficient) exhibited large fluctuations over time; however, it also exhibited specific periodic temporal structure over different time scales (1.5hr-24hr periods) that was consistent across subjects. We investigated the correlation of the phases of these network periodicities with the seizure onset by using circular statistics. The results showed that the instantaneous phases of the 3.5hr, 5.5hr, 12hr and 24hr network degree periodic components are not uniformly distributed, suggesting that functional network properties are related to seizure generation and occurrence.


Asunto(s)
Encéfalo/fisiopatología , Electroencefalografía , Epilepsia/fisiopatología , Red Nerviosa/fisiopatología , Humanos
7.
Artículo en Inglés | MEDLINE | ID: mdl-26736665

RESUMEN

Automatic detection and removal of muscle artifacts plays an important role in long-term scalp electroencephalography (EEG) monitoring, and muscle artifact detection algorithms have been intensively investigated. This paper proposes an algorithm for automatic muscle artifacts detection and removal using canonical correlation analysis (CCA) and wavelet transform (WT) in epochs from long-term EEG recordings. The proposed method first performs CCA analysis and then conducts wavelet decomposition on the canonical components within a specific frequency range and selects a subset of the wavelet coefficients for subsequent processing. A set of features, including the mean of wavelet coefficients and the canonical component autocorrelation values, are extracted from the above analysis and subsequently used as input in a random forest (RF) classifier. The RF classifier produces a similarity measure between observations and selects a subset of the most important features by comparing the original data with a set of synthetic data that is constructed based on the latter. The RF predictor output is finally used in combination with unsupervised clustering algorithms to discriminate between contaminated and non-contaminated EEG epochs. The proposed method is evaluated in epochs of 30 min from scalp EEG recordings obtained from three patients with epilepsy and yields a sensitivity of 71% and 80%, as well as a specificity of 81% and 85% for k-means and spectral clustering, respectively.


Asunto(s)
Artefactos , Electroencefalografía/métodos , Epilepsia/diagnóstico , Algoritmos , Humanos , Movimiento , Músculo Esquelético/fisiopatología , Cuero Cabelludo/fisiopatología , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador , Análisis de Ondículas
8.
Reproduction ; 148(3): 259-70, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24920664

RESUMEN

Sertoli cells (SCs) play an important physiological role in the testis, as they support, nourish, and protect the germ cells. As protection of the developing spermatozoa is an emerging aspect of reproductive physiology, this study examined the expression pattern of innate immune-related genes, including avian ß-defensins (AvBDs), Toll-like receptors (TLRs), and cytokines, and investigated the time course of an inflammatory response in rooster SCs triggered by exposure to the bacterial endotoxin lipopolysaccharide (LPS). SCs were isolated from 6-week-old chicken, cultured in vitro, and stimulated with 1 µg/ml LPS at different time courses (0, 6, 12, 24, and 48  h). Data on expression analysis revealed that all ten members of the chicken TLR family, nine members of the AvBD family, as well as eight cytokine genes were expressed in SCs. Quantitative real-time PCR analysis revealed that LPS treatment resulted in significant induction of the expression levels of six TLRs, six AvBDs, and four cytokine genes, while two cytokine genes were downregulated and two other genes were unchanged. The increasing interleukin 1ß (IL1ß) production was confirmed in the conditioned medium. Furthermore, the phagocytosis of SCs was increased after LPS treatment. In conclusion, these findings provide evidence that SCs express innate immune-related genes and respond directly to bacterial ligands. These genes represent an important component of the immune system, which could be integrated into semen, and present a distinctive constituent of the protective repertoire of the testis against ascending infections.


Asunto(s)
Citocinas/metabolismo , Inmunidad Innata/inmunología , Lipopolisacáridos/farmacología , Células de Sertoli/inmunología , Animales , Células Cultivadas , Pollos , Citocinas/genética , Inmunidad Innata/efectos de los fármacos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Fagocitosis/inmunología , Células de Sertoli/efectos de los fármacos , Células de Sertoli/metabolismo
9.
Artículo en Inglés | MEDLINE | ID: mdl-25570574

RESUMEN

Seizure detection and prediction studies using scalp- or intracranial-EEG measurements often focus on short-length recordings around the occurrence of the seizure, normally ranging between several seconds and up to a few minutes before and after the event. The underlying assumption in these studies is the presence of a relatively constant EEG activity in the interictal period, that is presumably interrupted by the occurrence of a seizure, at the time the seizure starts or slightly earlier. In this study, we put this assumption under test, by examining long-duration scalp EEG recordings, ranging between 22 and 72 hours, of five patients with epilepsy. For each patient, we construct functional brain networks, by calculating correlations between the scalp electrodes, and examine how these networks vary in time. The results suggest not only that the network varies over time, but it does so in a periodic fashion, with periods ranging between 11 and 25 hours.


Asunto(s)
Encéfalo/fisiopatología , Electroencefalografía/métodos , Epilepsia/fisiopatología , Cuero Cabelludo/fisiopatología , Electrodos , Humanos , Red Nerviosa/fisiopatología , Periodicidad , Factores de Tiempo
10.
Vet Res Commun ; 37(2): 115-22, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23381563

RESUMEN

Avian ß-defensins (AvßDs) constitute a family of antimicrobial peptides that are critical to innate immunity in chickens, providing protection against microbial pathogens including Salmonella Enteritidis (SE). As apart from the digestive tract another main route of SE colonization in birds is via infection of the oviduct and specifically of the vagina, the aim of this study was to investigate the expression of the complete family of AvßDs, in the chicken vagina in vivo, to determine whether sexual maturation affects their mRNA abundance and to investigate whether SE infection alters the vaginal AvßDs expression. Expression analysis revealed that 11 members of the AvßD family were expressed in the chicken vagina. Quantitative real-time PCR analysis revealed that the mRNA abundance of five AvßDs was up regulated and of one AvßD was down regulated with respect to sexual maturation. In addition SE infection resulted in a significant induction of AvßD5, 7, 10, 11, 12 and 14 in the vagina of sexually mature birds, and in a significant induction of AvßD5 and 11 in the vagina of aged birds. These findings provide strong evidence to suggest that an AvßD-mediated immune response mechanism exists in the chicken vagina providing protection against bacterial pathogens including Salmonella species.


Asunto(s)
Pollos , Enfermedades de las Aves de Corral/microbiología , Salmonelosis Animal/microbiología , Salmonella enteritidis/inmunología , Maduración Sexual/fisiología , beta-Defensinas/biosíntesis , Animales , Femenino , Enfermedades de las Aves de Corral/genética , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/metabolismo , ARN Mensajero/química , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Salmonelosis Animal/genética , Salmonelosis Animal/inmunología , Salmonelosis Animal/metabolismo , Maduración Sexual/genética , Maduración Sexual/inmunología , Estadísticas no Paramétricas , Vagina/inmunología , Vagina/microbiología , beta-Defensinas/genética , beta-Defensinas/inmunología
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