737 results on '"Demertzi A"'
Search Results
2. Unravelling consciousness and brain function through the lens of time, space, and information
- Author
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Luppi, Andrea I., Rosas, Fernando E., Mediano, Pedro A.M., Demertzi, Athena, Menon, David K., and Stamatakis, Emmanuel A.
- Published
- 2024
- Full Text
- View/download PDF
3. Dynamic Functional Hyperconnectivity After Psilocybin Intake Is Primarily Associated With Oceanic Boundlessness
- Author
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Mortaheb, Sepehr, Fort, Larry D., Mason, Natasha L., Mallaroni, Pablo, Ramaekers, Johannes G., and Demertzi, Athena
- Published
- 2024
- Full Text
- View/download PDF
4. Determination of nitrogen-containing organic compounds in commercially available recycled cardboards intended for food contact applications
- Author
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Parigoridi, Ioanna-Efpraxia, Tsoumani, Eleftheria, Akrida-Demertzi, Konstantoula, and Demertzis, Panagiotis G.
- Published
- 2024
- Full Text
- View/download PDF
5. Prolonged microgravity induces reversible and persistent changes on human cerebral connectivity
- Author
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Jillings, Steven, Pechenkova, Ekaterina, Tomilovskaya, Elena, Rukavishnikov, Ilya, Jeurissen, Ben, Van Ombergen, Angelique, Nosikova, Inna, Rumshiskaya, Alena, Litvinova, Liudmila, Annen, Jitka, De Laet, Chloë, Schoenmaekers, Catho, Sijbers, Jan, Petrovichev, Victor, Sunaert, Stefan, Parizel, Paul M., Sinitsyn, Valentin, Eulenburg, Peter zu, Laureys, Steven, Demertzi, Athena, and Wuyts, Floris L.
- Published
- 2023
- Full Text
- View/download PDF
6. Pathogens in the Food Chain: Escherichia coli Strains in Raw Milk Originating from Ewes Treated for Mastitis with Various Therapeutic Protocols
- Author
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Konstantina Fotou, Georgios Rozos, Konstantinos Zaralis, Aikaterini Dadamogia, Elisavet Stavropoulou, Panagiotis Demertzis, Konstantoula Akrida-Demertzi, Athina Tzora, and Chrysoula (Chrysa) Voidarou
- Subjects
Escherichia coli ,raw milk ,antimicrobial resistance ,virulence factors ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Dairy products from ovine milk are very popular in the Mediterranean countries and are gaining a large portion of the market in EU countries and worldwide. EU legislation permits the dairy processing of raw ovine milk under certain conditions. To study the ecology and prevalence of E. coli in raw ewes’ milk and assess thus the public health risk, samples of milk were taken from 75 different sheep farms in the rural area of Epirus, Greece. The initial sampling was conducted in clinically healthy animals which were noted as controls (group A). From the same farms, samples were taken from animals with clinical mastitis and before treatment (group B). For therapeutic purposes, to some animals, a combination of penicillin and streptomycin was administrated (group C1), or tetracycline (group C2), or enrofloxacin (group C3). Finally, samples of raw milk were taken from the C groups, on the first day after the withdrawal period of the antibiotics used, when the milk is permitted to enter the food chain. In total, 97 isolates of Escherichia coli were recovered from all groups. Analysis revealed an impressive increase in E. coli strains in the milk of group B (39.33%) with respect to group A (5%). Even after treatment, although the prevalence was decreased, it was still found to be higher in the C groups than group A. E. coli O157:H7 strains absent from group A were detected in all other groups in relatively low occurrence rates with respect to other “O” serotypes but non-O157:H7 strains. Virulence factors such as the production of toxins (32.60% for serotoxin 1 and 18.47% for serotoxin 2) and hemolysin (42.39%) as well as biofilm formation capacity (52.17% of the total) and ESDL production (43.47% of the total) were also studied. All strains were also tested for susceptibility against 12 antibiotics by the MIC method and the results showed a high prevalence of resistance and multi-resistance. The presence of various resistant strains to antibiotics and pathogenic “O” serotype strains in the milk when it can enter the food chain again is an alarming conclusion.
- Published
- 2024
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- View/download PDF
7. Evaluation of three extraction methods for the isolation of PAHs from recycled paperboard materials intended for food contact applications
- Author
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Parigoridi, Ioanna-Efpraxia, Tsoumani, Eleftheria, Akrida-Demertzi, Konstantoula, and Demertzis, Panagiotis G.
- Published
- 2023
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- View/download PDF
8. Visual fixation in the vegetative state: an observational case series PET study
- Author
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Majerus Steve, Demertzi Athena, Gosseries Olivia, Boly Mélanie, Schnakers Caroline, Vanhaudenhuyse Audrey, Bruno Marie-Aurélie, Moonen Gustave, Hustinx Roland, and Laureys Steven
- Subjects
Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Assessment of visual fixation is commonly used in the clinical examination of patients with disorders of consciousness. However, different international guidelines seem to disagree whether fixation is compatible with the diagnosis of the vegetative state (i.e., represents "automatic" subcortical processing) or is a sufficient sign of consciousness and higher order cortical processing. Methods We here studied cerebral metabolism in ten patients with chronic post-anoxic encephalopathy and 39 age-matched healthy controls. Five patients were in a vegetative state (without fixation) and five presented visual fixation but otherwise showed all criteria typical of the vegetative state. Patients were matched for age, etiology and time since insult and were followed by repeated Coma Recovery Scale-Revised (CRS-R) assessments for at least 1 year. Sustained visual fixation was considered as present when the eyes refixated a moving target for more than 2 seconds as defined by CRS-R criteria. Results Patients without fixation showed metabolic dysfunction in a widespread fronto-parietal cortical network (with only sparing of the brainstem and cerebellum) which was not different from the brain function seen in patients with visual fixation. Cortico-cortical functional connectivity with visual cortex showed no difference between both patient groups. Recovery rates did not differ between patients without or with fixation (none of the patients showed good outcome). Conclusions Our findings suggest that sustained visual fixation in (non-traumatic) disorders of consciousness does not necessarily reflect consciousness and higher order cortical brain function.
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- 2010
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9. Prolonged microgravity induces reversible and persistent changes on human cerebral connectivity
- Author
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Steven Jillings, Ekaterina Pechenkova, Elena Tomilovskaya, Ilya Rukavishnikov, Ben Jeurissen, Angelique Van Ombergen, Inna Nosikova, Alena Rumshiskaya, Liudmila Litvinova, Jitka Annen, Chloë De Laet, Catho Schoenmaekers, Jan Sijbers, Victor Petrovichev, Stefan Sunaert, Paul M. Parizel, Valentin Sinitsyn, Peter zu Eulenburg, Steven Laureys, Athena Demertzi, and Floris L. Wuyts
- Subjects
Biology (General) ,QH301-705.5 - Abstract
rs-fMRI is used to investigate human brain connectivity changes induced by prolonged microgravity in cosmonauts before and after spaceflight, with both persistent and reversible location specific changes in connectivity being observed.
- Published
- 2023
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10. Overview of Ecology and Aspects of Antibiotic Resistance in Campylobacter spp. Isolated from Free-Grazing Chicken Tissues in Rural Households
- Author
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Argyrios Dermatas, Georgios Rozos, Konstantinos Zaralis, Aikaterini Dadamogia, Konstantina Fotou, Eugenia Bezirtzoglou, Konstantoula Akrida-Demertzi, Panagiotis Demertzis, and Chrysoula (Chrysa) Voidarou
- Subjects
Campylobacter ,ecology ,antibiotic resistance ,free-grazing chicken ,blaOxA-61 ,tet(O) ,Biology (General) ,QH301-705.5 - Abstract
Rural households all over the world rear backyard chicken mainly for their own consumption and, to a lesser extent, for barter trade. These chickens represent a staple dish with numerous culinary variations and a cheap source of protein. Although some Campylobacter species, and particularly Campylobacter jejuni and Campylobacter coli, have been associated with industrial poultry carcasses, studies concerning the ecology of this genus in rural households do not exist. To assess the prevalence of Campylobacter species in the tissues of backyard chickens, samples were collected from birds Gallus domesticus bred in households in the rural area of Epirus (Greece), and Campylobacter strains were isolated by quantitative methods at 37 °C and 42 °C. In total, 256 strains were identified, belonging to 17 Campylobacter species, with C. jejuni and C. coli being the most prevalent. From the four ecological parameters studied (size of the flock, presence of small ruminants in the same household, presence of other poultry species in the same household, and feeding leftovers of the household), the size of the flock and the presence of small ruminants and/or pigs in the same household mostly affected the distribution of these strains. To study the phenotypical resistance against 14 antibiotics, 215 strains were selected. The results showed a high prevalence of multidrug-resistance (MDR) strains extending to all classes of antibiotics. Further genome analysis revealed the presence of genes coding resistance (blaOxA-61, tet(O), tet(A) cmeA, cmeB, cmeC, and gyrA (Thr-86-Ile mutation)), with the efflux pump CmeABC being the most prevalent. All antimicrobial resistance-encoded genes co-circulated, except for blaOXA-61, which moved independently. The minimum inhibitory concentration (MIC) values of two out of three antibiotics (representing different classes) were reduced when the strains tested were exposed to carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a known efflux pump inhibitor. The same result was obtained with the addition of CCCP to the MIC values of bile salts. These results lead to the conclusion that Campylobacter species are present in an impressive diversity in backyard chicken tissues and that they exert a significant resistance to antibiotics, raising a potential danger for public health.
- Published
- 2024
- Full Text
- View/download PDF
11. E-Learning for Deaf Adults from a User-Centered Perspective
- Author
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Pappas, Marios A., Demertzi, Eleftheria, Papagerasimou, Yannis, Koukianakis, Lefteris, Kouremenos, Dimitris, Loukidis, Ioannis, and Drigas, Athanasios S.
- Abstract
Deaf individuals present differences compared to their hearing peers in terms of their learning profile. In addition, deaf adults seem to still be socially excluded nowadays, given that the transition from school to work is more difficult for people with hearing loss. This study aims to analyze the cognitive characteristics of deaf adults, as well as the way they learn better, for the development of an innovative and user-friendly e-learning platform, which will be adapted to the educational needs of the target group. Fifty-three deaf or hard-of-hearing adults participated in the field research for the needs of this study. According to the results, participants prefer e-learning modules with continuity in terms of the content, which offer comprehension questions during the sessions, as well as practice exercises after their completion. Furthermore, participants had positive attitudes towards the use of special graphics and explanatory videos.
- Published
- 2018
12. Low-dimensional organization of global brain states of reduced consciousness
- Author
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Perl, Yonatan Sanz, Pallavicini, Carla, Piccinini, Juan, Demertzi, Athena, Bonhomme, Vincent, Martial, Charlotte, Panda, Rajanikant, Alnagger, Naji, Annen, Jitka, Gosseries, Olivia, Ibañez, Agustin, Laufs, Helmut, Sitt, Jacobo D., Jirsa, Viktor K., Kringelbach, Morten L., Laureys, Steven, Deco, Gustavo, and Tagliazucchi, Enzo
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- 2023
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13. Low-dimensional organization of global brain states of reduced consciousness
- Author
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Yonatan Sanz Perl, Carla Pallavicini, Juan Piccinini, Athena Demertzi, Vincent Bonhomme, Charlotte Martial, Rajanikant Panda, Naji Alnagger, Jitka Annen, Olivia Gosseries, Agustin Ibañez, Helmut Laufs, Jacobo D. Sitt, Viktor K. Jirsa, Morten L. Kringelbach, Steven Laureys, Gustavo Deco, and Enzo Tagliazucchi
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CP: Neuroscience ,Biology (General) ,QH301-705.5 - Abstract
Summary: Brain states are frequently represented using a unidimensional scale measuring the richness of subjective experience (level of consciousness). This description assumes a mapping between the high-dimensional space of whole-brain configurations and the trajectories of brain states associated with changes in consciousness, yet this mapping and its properties remain unclear. We combine whole-brain modeling, data augmentation, and deep learning for dimensionality reduction to determine a mapping representing states of consciousness in a low-dimensional space, where distances parallel similarities between states. An orderly trajectory from wakefulness to patients with brain injury is revealed in a latent space whose coordinates represent metrics related to functional modularity and structure-function coupling, increasing alongside loss of consciousness. Finally, we investigate the effects of model perturbations, providing geometrical interpretation for the stability and reversibility of states. We conclude that conscious awareness depends on functional patterns encoded as a low-dimensional trajectory within the vast space of brain configurations.
- Published
- 2023
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14. Neuroplasticity in F16 fighter jet pilots
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Wilhelmina E. Radstake, Steven Jillings, Steven Laureys, Athena Demertzi, Stefan Sunaert, Angelique Van Ombergen, and Floris L. Wuyts
- Subjects
resting state fMRI ,fighter pilots ,neuroplasticity ,gravity transitions ,brain ,MRI ,Physiology ,QP1-981 - Abstract
Exposure to altered g-levels causes unusual sensorimotor demands that must be dealt with by the brain. This study aimed to investigate whether fighter pilots, who are exposed to frequent g-level transitions and high g-levels, show differential functional characteristics compared to matched controls, indicative of neuroplasticity. We acquired resting-state functional magnetic resonance imaging data to assess brain functional connectivity (FC) changes with increasing flight experience in pilots and to assess differences in FC between pilots and controls. We performed whole-brain exploratory and region-of-interest (ROI) analyses, with the right parietal operculum 2 (OP2) and the right angular gyrus (AG) as ROIs. Our results show positive correlations with flight experience in the left inferior and right middle frontal gyri, and in the right temporal pole. Negative correlations were observed in primary sensorimotor regions. We found decreased whole-brain functional connectivity of the left inferior frontal gyrus in fighter pilots compared to controls and this cluster showed decreased functional connectivity with the medial superior frontal gyrus. Functional connectivity increased between the right parietal operculum 2 and the left visual cortex, and between the right and left angular gyrus in pilots compared to controls. These findings suggest altered motor, vestibular, and multisensory processing in the brains of fighter pilots, possibly reflecting coping strategies to altered sensorimotor demands during flight. Altered functional connectivity in frontal areas may reflect adaptive cognitive strategies to cope with challenging conditions during flight. These findings provide novel insights into brain functional characteristics of fighter pilots, which may be of interest to humans traveling to space.
- Published
- 2023
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15. Functional network antagonism and consciousness
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Athena Demertzi, Aaron Kucyi, Adrián Ponce-Alvarez, Georgios A. Keliris, Susan Whitfield-Gabrieli, and Gustavo Deco
- Subjects
Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
AbstractSpontaneous brain activity changes across states of consciousness. A particular consciousness-mediated configuration is the anticorrelations between the default mode network and other brain regions. What this antagonistic organization implies about consciousness to date remains inconclusive. In this Perspective Article, we propose that anticorrelations are the physiological expression of the concept of segregation, namely the brain’s capacity to show selectivity in the way areas will be functionally connected. We postulate that this effect is mediated by the process of neural inhibition, by regulating global and local inhibitory activity. While recognizing that this effect can also result from other mechanisms, neural inhibition helps the understanding of how network metastability is affected after disrupting local and global neural balance. In combination with relevant theories of consciousness, we suggest that anticorrelations are a physiological prior that can work as a marker of preserved consciousness. We predict that if the brain is not in a state to host anticorrelations, then most likely the individual does not entertain subjective experience. We believe that this link between anticorrelations and the underlying physiology will help not only to comprehend how consciousness happens, but also conceptualize effective interventions for treating consciousness disorders in which anticorrelations seem particularly affected.
- Published
- 2022
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16. An Overview of Privacy Dimensions on the Industrial Internet of Things (IIoT)
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Vasiliki Demertzi, Stavros Demertzis, and Konstantinos Demertzis
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identity privacy ,location privacy ,footprint privacy ,multidimensional privacy ,privacy threats ,privacy principles ,Industrial engineering. Management engineering ,T55.4-60.8 ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
The rapid advancements in technology have given rise to groundbreaking solutions and practical applications in the field of the Industrial Internet of Things (IIoT). These advancements have had a profound impact on the structures of numerous industrial organizations. The IIoT, a seamless integration of the physical and digital realms with minimal human intervention, has ushered in radical changes in the economy and modern business practices. At the heart of the IIoT lies its ability to gather and analyze vast volumes of data, which is then harnessed by artificial intelligence systems to perform intelligent tasks such as optimizing networked units’ performance, identifying and correcting errors, and implementing proactive maintenance measures. However, implementing IIoT systems is fraught with difficulties, notably in terms of security and privacy. IIoT implementations are susceptible to sophisticated security attacks at various levels of networking and communication architecture. The complex and often heterogeneous nature of these systems makes it difficult to ensure availability, confidentiality, and integrity, raising concerns about mistrust in network operations, privacy breaches, and potential loss of critical, personal, and sensitive information of the network's end-users. To address these issues, this study aims to investigate the privacy requirements of an IIoT ecosystem as outlined by industry standards. It provides a comprehensive overview of the IIoT, its advantages, disadvantages, challenges, and the imperative need for industrial privacy. The research methodology encompasses a thorough literature review to gather existing knowledge and insights on the subject. Additionally, it explores how the IIoT is transforming the manufacturing industry and enhancing industrial processes, incorporating case studies and real-world examples to illustrate its practical applications and impact. Also, the research endeavors to offer actionable recommendations on implementing privacy-enhancing measures and establishing a secure IIoT ecosystem.
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- 2023
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17. Biodiversity Dynamics of Campylobacter Species in Chicken Tissues in Rural Households in Region Epirus, Greece
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Argyrios Dermatas, Georgios Rozos, Chrysoula (Chrysa) Voidarou, Konstantoula Akrida-Demertzi, and Panagiotis Demertzis
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Campylobacter ,biodiversity ,chicken ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The Campylobacter species is considered as an emerging zoonotic threat to public health. C. jejuni and C. coli are the most studied species, yet a variety of other species of the same genus were found to be the causative agents of other diseases. Chicken meat has been described as an excellent vehicle for the transmission of some Campylobacter species but most of the relevant research has been conducted in urban populations and concerned meat of industrial-grade birds. To investigate the abundance and prevalence of the Campylobacter genus in rural free-grazing chicken, quantitative and qualitative methods at 37 and at 42 °C were employed. The possible correlation of the prevalence with certain epidemiological factors (size of the flock, presence of other poultry species, presence of small ruminants, feeding concentrates, or leftovers) has been also investigated. In total, 242–249 strains (depending on the method) belonging to the following 18 different Campylobacter species have been isolated: C. coli, C. rectus, C. hominis, C. helveticus, C. upsaliensis, C. jejuni, C. avium, C. fetus, C. hepaticus., C. lari, C. sputorum, C. mucosalis, C. gracilis, C. showae, C. hyointestinalis, C. concisus, C. cuniculorum, and C. ureolyticus. The size of the flock and the presence of small ruminants in the same household were the most influential factors affecting the prevalence of most species. Campylobacter species biodiversity can be attributed to environmental, zoonotic, or anthropogenic contamination. Rural populations should be educated about the importance of self-protection measures during their contact with their poultry and the necessity to cook sufficiently the meat.
- Published
- 2023
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18. An Overview of Cyber Threats, Attacks and Countermeasures on the Primary Domains of Smart Cities
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Vasiliki Demertzi, Stavros Demertzis, and Konstantinos Demertzis
- Subjects
smart city ,cyber threats ,cyber attacks ,smart government ,smart mobility ,smart environment ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A smart city is where existing facilities and services are enhanced by digital technology to benefit people and companies. The most critical infrastructures in this city are interconnected. Increased data exchange across municipal domains aims to manage the essential assets, leading to more automation in city governance and optimization of the dynamic offered services. However, no clear guideline or standard exists for modeling these data flows. As a result, operators, municipalities, policymakers, manufacturers, solution providers, and vendors are forced to accept systems with limited scalability and varying needs. Nonetheless, it is critical to raise awareness about smart-city cybersecurity and implement suitable measures to safeguard citizens’ privacy and security because cyber threats seem to be well-organized, diverse, and sophisticated. This study aims to present an overview of cyber threats, attacks, and countermeasures on the primary domains of smart cities (smart government, smart mobility, smart environment, smart living, smart healthcare, smart economy, and smart people). It aims to present information extracted from the state of the art so policymakers can perceive the critical situation and simultaneously be a valuable resource for the scientific community. It also seeks to offer a structural reference model that may guide the architectural design and implementation of infrastructure upgrades linked to smart city networks.
- Published
- 2023
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19. Ethics of life-sustaining treatment in locked-in syndrome: A Chinese survey
- Author
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Yan, Yifan, Demertzi, Athena, Xia, Yinyan, Wang, Jing, Hu, Nantu, Zhang, Zhiliang, Di, Haibo, and Laureys, Steven
- Published
- 2020
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20. Life cycle assessment of the production of composite sandwich panels for structural floor’s rehabilitation
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Demertzi, M., Silvestre, J.D., and Durão, V.
- Published
- 2020
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21. Life cycle assessment of alternative building floor rehabilitation systems
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Demertzi, M., Silvestre, J., Garrido, M., Correia, J.R., Durão, V., and Proença, M.
- Published
- 2020
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22. Vestibular Morphological Asymmetry Associated With Motion Sickness Susceptibility
- Author
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Takumi Harada, Tomoko Sugawara, Taeko Ito, Yoshiro Wada, Masaki Fukunaga, Norihiro Sadato, Stephen K. Larroque, Athena Demertzi, Steven Laureys, and Hiroyuki Sakai
- Subjects
motion sickness ,vestibular ,morphology ,asymmetry ,inner ear ,resting state ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Sensory conflicts leading to motion sickness can occur not only between but also within sensory modalities. The vestibular organs are located in both left and right inner ears, and their misalignment can be a source of self-motion related sensory conflicts. In the current study, using inner ear magnetic resonance imaging, we examined whether morphological asymmetry of the bilateral vestibular organs was associated with motion sickness susceptibility. The results showed a larger position asymmetry of bilateral vestibular organs in individuals with high rather than low susceptibility. In addition, vestibular position asymmetry was associated with reciprocal interaction (negative resting state functional connectivity) between vestibular and visuocortical regions in lowly, but not highly, susceptible individuals. In conclusion, these findings suggest that vestibular morphological asymmetry can be a source of sensory conflicts in individuals with dysfunctional reciprocal visuo-vestibular interactions, a putative neural mechanism for resolving sensory conflicts.
- Published
- 2021
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23. Attitudes towards Personhood in the Locked-in Syndrome: from Third- to First- Person Perspective and to Interpersonal Significance
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Nizzi, Marie-Christine, Blandin, Veronique, and Demertzi, Athena
- Published
- 2020
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24. Perturbations in dynamical models of whole-brain activity dissociate between the level and stability of consciousness.
- Author
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Yonatan Sanz Perl, Carla Pallavicini, Ignacio Pérez Ipiña, Athena Demertzi, Vincent Bonhomme, Charlotte Martial, Rajanikant Panda, Jitka Annen, Agustin Ibañez, Morten Kringelbach, Gustavo Deco, Helmut Laufs, Jacobo Sitt, Steven Laureys, and Enzo Tagliazucchi
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Consciousness transiently fades away during deep sleep, more stably under anesthesia, and sometimes permanently due to brain injury. The development of an index to quantify the level of consciousness across these different states is regarded as a key problem both in basic and clinical neuroscience. We argue that this problem is ill-defined since such an index would not exhaust all the relevant information about a given state of consciousness. While the level of consciousness can be taken to describe the actual brain state, a complete characterization should also include its potential behavior against external perturbations. We developed and analyzed whole-brain computational models to show that the stability of conscious states provides information complementary to their similarity to conscious wakefulness. Our work leads to a novel methodological framework to sort out different brain states by their stability and reversibility, and illustrates its usefulness to dissociate between physiological (sleep), pathological (brain-injured patients), and pharmacologically-induced (anesthesia) loss of consciousness.
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- 2021
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25. Wine production using free and immobilized kefir culture on natural supports
- Author
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Nikolaou, Anastasios, Tsakiris, Argyrios, Kanellaki, Maria, Bezirtzoglou, Eugenia, Akrida-Demertzi, Konstantoula, and Kourkoutas, Yiannis
- Published
- 2019
- Full Text
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26. Probability‐type, Shewhart‐type and EWMA control charts for individual observations from the two‐parameter Lindley distribution.
- Author
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Demertzi, Elisavet and Psarakis, Stelios
- Subjects
- *
QUALITY control charts , *RELIABILITY in engineering , *EMOTIONAL intelligence , *TELECOMMUNICATION systems , *CONTINUOUS distributions , *INTELLIGENCE tests - Abstract
Lindley distribution is a continuous distribution with various applications some of which are in medicine, genetics, epidemiology, biology, finance and actuarial sciences, ecology, meteorology, sociology, demography, agriculture, hydrology, geosciences, reliability and engineering, life testing and survival analysis, airborne systems and communications, environmental studies and modeling and describing of human mistakes, strikes, accidents, behavioural and emotional or IQ test scores and waiting times of customers in queues until service, etc. Due to its variety of applications, it appears to be important that control charts for detected shifts in a process should be constructed under the assumption that the quality characteristic of interest follows a Lindley‐related distribution. Here, we construct probability‐type, Shewhart‐type and EWMA control charts (and deal with the optimal choice of its parameters) for individual observations from the two‐parameter Lindley distribution, investigate and compare their performance and illustrate them using examples with both simulated and real data. The whole analysis reveals the superiority of using skewness correction for the construction of the control charts against not using it. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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27. Overview of Ecology and Aspects of Antibiotic Resistance in Campylobacter spp. Isolated from Free-Grazing Chicken Tissues in Rural Households.
- Author
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Dermatas, Argyrios, Rozos, Georgios, Zaralis, Konstantinos, Dadamogia, Aikaterini, Fotou, Konstantina, Bezirtzoglou, Eugenia, Akrida-Demertzi, Konstantoula, Demertzis, Panagiotis, and Voidarou, Chrysoula
- Subjects
CHICKENS ,DRUG resistance in bacteria ,CAMPYLOBACTER ,CAMPYLOBACTER coli ,CAMPYLOBACTER jejuni ,ANTIBIOTIC residues ,RURAL poor - Abstract
Rural households all over the world rear backyard chicken mainly for their own consumption and, to a lesser extent, for barter trade. These chickens represent a staple dish with numerous culinary variations and a cheap source of protein. Although some Campylobacter species, and particularly Campylobacter jejuni and Campylobacter coli, have been associated with industrial poultry carcasses, studies concerning the ecology of this genus in rural households do not exist. To assess the prevalence of Campylobacter species in the tissues of backyard chickens, samples were collected from birds Gallus domesticus bred in households in the rural area of Epirus (Greece), and Campylobacter strains were isolated by quantitative methods at 37 °C and 42 °C. In total, 256 strains were identified, belonging to 17 Campylobacter species, with C. jejuni and C. coli being the most prevalent. From the four ecological parameters studied (size of the flock, presence of small ruminants in the same household, presence of other poultry species in the same household, and feeding leftovers of the household), the size of the flock and the presence of small ruminants and/or pigs in the same household mostly affected the distribution of these strains. To study the phenotypical resistance against 14 antibiotics, 215 strains were selected. The results showed a high prevalence of multidrug-resistance (MDR) strains extending to all classes of antibiotics. Further genome analysis revealed the presence of genes coding resistance (bla
OxA-61 , tet(O), tet(A) cmeA, cmeB, cmeC, and gyrA (Thr-86-Ile mutation)), with the efflux pump CmeABC being the most prevalent. All antimicrobial resistance-encoded genes co-circulated, except for blaOXA-61 , which moved independently. The minimum inhibitory concentration (MIC) values of two out of three antibiotics (representing different classes) were reduced when the strains tested were exposed to carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a known efflux pump inhibitor. The same result was obtained with the addition of CCCP to the MIC values of bile salts. These results lead to the conclusion that Campylobacter species are present in an impressive diversity in backyard chicken tissues and that they exert a significant resistance to antibiotics, raising a potential danger for public health. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
28. New measurement of the diffusion of carbon dioxide on non-porous amorphous solid water.
- Author
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He, Jiao, Pérez Rickert, Paula Caroline, Suhasaria, Tushar, Sohier, Orianne, Bäcker, Tia, Demertzi, Dimitra, Vidali, Gianfranco, and Henning, Thomas K.
- Subjects
DIFFUSION measurements ,AMORPHOUS substances ,CARBON dioxide ,INTERSTELLAR molecules ,ICE sheets - Abstract
The diffusion of molecules on interstellar grain surfaces is one of the most important driving forces for the molecular complexity in the interstellar medium. Due to the lack of laboratory measurements, astrochemical modeling of grain surface processes usually assumes a constant ratio between the diffusion energy barrier and the desorption energy. This over-simplification inevitably causes large uncertainty in model predictions. We present a new measurement of the diffusion of CO $ _2 $ 2 molecules on the surface of non-porous amorphous solid water (np-ASW), an analog of the ice mantle that covers cosmic dust grains. A small coverage of CO $ _2 $ 2 was deposited onto an np-ASW surface at 40 K, the subsequent warming of the ice activated the diffusion of CO $ _2 $ 2 molecules, and a transition from isolated CO $ _2 $ 2 to CO $ _2 $ 2 clusters was seen in the infrared spectra. To obtain the diffusion energy barrier and pre-exponential factor simultaneously, a set of isothermal experiments were carried out. The values for the diffusion energy barrier and pre-exponential factor were found to be $ 1300\pm 110 $ 1300 ± 110 K and $ 10^{7.6\pm 0.8} $ 10 7.6 ± 0.8 s $ ^{-1} $ − 1 . A comparison with prior laboratory measurements on diffusion is discussed. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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29. Assessment of Seasonal and Diurnal Variations of Alkaline Phosphatase Activity in Pasteurized Milk
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Vaia Gerokomou, Georgios Rozos, Panagiotis Demertzis, and Konstantoula Akrida-Demertzi
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food microbiology ,food industry ,alkaline phosphatase ,milk ,milk pasteurization ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The present study was conducted to detect the concentration levels of ALP (alkaline phosphatase) in pasteurized milk and determine whether the pasteurization was successful or not, according to WHO Directives, which clearly state that the ALP (alkaline phosphatase) substance in pasteurized milk must be totally inactivated, by implementing a newly developed method. The study, additionally, focused on repeatability, stability of results, the effect of the environmental temperature, the effect of the different origins of the milk and convenience with respect to performance characteristics of three methods for the detection of ALP. The milk samples were collected from different areas of Greece during February 2016–February 2018 and May 2019–January 2020. The novel enzymatic biochemical method, named the “AP test”, showed superior characteristics for a diversity of materials such as milk, whey, cheese and butter in comparison to the other two methods that were used for screening and quantitative estimation of the concentration of ALP in samples.
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- 2022
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30. Body composition and arterial stiffness in pediatric patients with chronic kidney disease
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Karava, Vasiliki, Printza, Nikoleta, Dotis, John, Demertzi, Despoina, Antza, Christina, Kotsis, Vasilios, and Papachristou, Fotios
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Body composition -- Health aspects ,Chronic kidney failure -- Complications and side effects ,Pediatric research ,Blood circulation disorders -- Risk factors ,Health - Abstract
Background This study investigated the impact of body composition in the arterial stiffness of children with chronic kidney disease (CKD). Methods Fat mass (FM), fat tissue index (FTI), fat-free mass (FFM), fat-free tissue index (FFTI), and FFTI/FTI were measured in 26 patients and 25 healthy controls by bio-impedance analysis. Data on patient's body mass index (BMI) for height-age, serum albumin, glomerular filtration rate (GFR), blood pressure status, and pulse wave velocity (PWV) were collected in patients. Results Patients presented lower levels of FM and FFM compared to healthy controls (p = 0.04 and p = 0.055 respectively). In patient group, BMI height-age z-score was positively correlated to FTI (r.sup.2 = 0.574, p < 0.001) and FFTI (r.sup.2 = 0.338, p = 0.001) and negatively correlated to FFTI/FTI (r.sup.2 = 0.263, p = 0.007). Serum albumin was positively correlated only with FFM among body composition data (r.sup.2 = 0.169, p = 0.037). PWV z-score was positively correlated to FFTI (r.sup.2 = 0.421, p = 0.006) and inversely correlated to FFTI/FTI [greater than or equal to] 2.5 (r.sup.2 = 0.317, p = 0.003). Patients with FFTI/FTI [greater than or equal to] 2.5 presented lower levels of PWV regardless the need for antihypertensive treatment. Serum albumin [greater than or equal to] 3.8 mg/dl and FFTI/FTI [greater than or equal to] 2.5 were independently associated with a lower risk for high PWV, after adjustment for age, sex, and GFR (OR 0.009, 95% CI 0.000-0.729 and OR 0.039, 95% CI 0.002-0.680). All underweight [2 (7.7%)] and overweight [4 (15.4%)] patients presented high PWV. Among normal weight patients, FFTI/FTI ratio [greater than or equal to] 2.5 was significantly associated with lower PWV z-score (p = 0.013). Conclusions Both underweight and overweight are associated with arterial stiffness. Targeting FFTI/FTI [greater than or equal to] 2.5 could be protective against cardiovascular disease in normal weight children., Author(s): Vasiliki Karava [sup.1] , Nikoleta Printza [sup.1] , John Dotis [sup.1] , Despoina Demertzi [sup.1] , Christina Antza [sup.2] , Vasilios Kotsis [sup.2] , Fotios Papachristou [sup.1] , Stella [...]
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- 2019
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31. Brain functional connectivity differentiates dexmedetomidine from propofol and natural sleep
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Guldenmund, P., Vanhaudenhuyse, A., Sanders, R.D., Sleigh, J., Bruno, M.A., Demertzi, A., Bahri, M.A., Jaquet, O., Sanfilippo, J., Baquero, K., Boly, M., Brichant, J.F., Laureys, S., and Bonhomme, V.
- Published
- 2017
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32. Environmental performance of expanded cork slab and granules through life cycle assessment
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Demertzi, Martha, Sierra-Pérez, Jorge, Paulo, Joana Amaral, Arroja, Luis, and Dias, Ana Cláudia
- Published
- 2017
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33. The Scientific Study of Consciousness Cannot and Should Not Be Morally Neutral
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Matan Mazor, Simon Brown, Anna Ciaunica, Athena Demertzi, Johannes Jacobus Fahrenfort, Nathan Faivre, Jolien Francken, Dominique Lamy, Bigna Lenggenhager, Michael Moutoussis, Marie-Christine Nizzi, Roy Salomon, David Soto, Timo Stein, Nitzan Lubianker, Laboratoire de Psychologie et NeuroCognition (LPNC ), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Cognitive Psychology, and IBBA
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[SCCO]Cognitive science ,SDG 16 - Peace ,SDG 16 - Peace, Justice and Strong Institutions ,16. Peace & justice ,General Psychology ,Justice and Strong Institutions - Abstract
Normative decisions about moral status are strongly coupled with beliefs and assumptions about consciousness. Whether an individual is able to experience their environment, feel pain and pleasure or reflect on their own experiences, have all been judged at some point as relevant to the moral question of whether they should be protected by law. The scientific study of consciousness has advanced our understanding of some of these empirical questions by revealing the capacities and limits of these dimensions of consciousness in different states and animal species. In light of the tight link with moral status, scientific discoveries in this field have direct implications on law and ethics. Furthermore, this link with ethics may place implicit pressure on the scientific community studying consciousness to justify current societal norms, rather than challenge them. Finally, given the important role of consciousness in determining moral standing, the use of non-human animals in the scientific study of consciousness introduces a direct conflict between scientific relevance and ethics – the more scientifically valuable an animal model is for studying consciousness, the more difficult it becomes to ethically justify compromises to its well-being for consciousness research. Here we call for a discussion of the immediate ethical corollaries of the body of knowledge that has been accumulated, and for a more explicit consideration of the role of ideology and ethics in the scientific study of consciousness, including the question of animal models of consciousness.
- Published
- 2022
34. A Hybrid Ontology Matching Mechanism for Adaptive Educational eLearning Environments.
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Demertzi, Vasiliki and Demertzis, Konstantinos
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SCHOOL environment ,WORLD Wide Web ,SEMANTIC Web ,ARTIFICIAL intelligence ,ONTOLOGY ,ONTOLOGIES (Information retrieval) ,DEEP learning - Abstract
Providing the same pedagogical and educational methods to all students is pedagogically ineffective. In contrast, the pedagogical strategies that adapt to the fundamental individual skills of the students have proved to be more effective. An important innovation in this direction is the adaptive educational systems (AESs) that adjust the teaching content on educational needs and students' skills. Effective utilization of these approaches can be enhanced with artificial intelligence (AI) and semantic web technologies that can increase data generation, access, flow, integration, and comprehension using the same open standards driving the World Wide Web. This study proposes a novel adaptive educational eLearning system (AEeLS) that can gather and analyze data from learning repositories and adapt these to the educational curriculum according to the student's skills and experience. It is an innovative hybrid machine learning system that combines a semi-supervised classification method for ontology matching and a recommendation mechanism that uses a sophisticated way from neighborhood-based collaborative and content-based filtering techniques to provide a personalized educational environment for each student. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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35. Whole-Brain Deactivations Precede Uninduced Mind-Blanking Reports.
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Boulakis, Paradeisios Alexandros, Mortaheb, Sepehr, van Calster, Laurens, Majerus, Steve, and Demertzi, Athena
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PARIETAL lobe ,BAYESIAN analysis ,UNIVARIATE analysis ,FUNCTIONAL magnetic resonance imaging ,THALAMIC nuclei ,METACOGNITION - Abstract
Mind-blanking (MB) is termed as the inability to report our immediate-past mental content. In contrast to mental states with reportable content, such as mind-wandering or sensory perceptions, the neural correlates of MB started getting elucidated only recently. A notable particularity that pertains to MB studies is the way MB is instructed for reporting, like by deliberately asking participants to "empty their minds." Such instructions were shown to induce fMRI activations in frontal brain regions, typically associated with metacognition and self-evaluative processes, suggesting that MB may be a result of intentional mental content suppression. Here, we aim at examining this hypothesis by determining the neural correlates of MB without induction. Using fMRI combined with experience-sampling in 31 participants (22 female), univariate analysis of MB reports revealed deactivations in occipital, frontal, parietal, and thalamic areas, but no activations in prefrontal regions. These findings were confirmed using Bayesian region-of-interest analysis on areas previously shown to be implicated in induced MB, where we report evidence for frontal deactivations during MB reports compared with other mental states. Contrast analysis between reports of MB and content-oriented mental states also revealed deactivations in the left angular gyrus. We propose that these effects characterize a neuronal profile of MB, where key thalamocortical nodes are unable to communicate and formulate reportable content. Collectively, we show that study instructions for MB lead to differential neural activation. These results provide mechanistic insights linked to the phenomenology of MB and point to the possibility of MB being expressed in different forms. [ABSTRACT FROM AUTHOR]
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- 2023
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36. Evaluating the carbon footprint of the cork sector with a dynamic approach including biogenic carbon flows
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Demertzi, Martha, Paulo, Joana Amaral, Faias, Sonia Pacheco, Arroja, Luís, and Dias, Ana Cláudia
- Published
- 2018
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37. Intrinsic functional connectivity reduces after first-time exposure to short-term gravitational alterations induced by parabolic flight
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Angelique Van Ombergen, Floris L. Wuyts, Ben Jeurissen, Jan Sijbers, Floris Vanhevel, Steven Jillings, Paul M. Parizel, Stefan Sunaert, Paul H. Van de Heyning, Vincent Dousset, Steven Laureys, and Athena Demertzi
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Medicine ,Science - Abstract
Abstract Spaceflight severely impacts the human body. However, little is known about how gravity and gravitational alterations affect the human brain. Here, we aimed at measuring the effects of acute exposure to gravity transitions. We exposed 28 naïve participants to repetitive alterations between normal, hyper- and microgravity induced by a parabolic flight (PF) and measured functional MRI connectivity changes. Scans were acquired before and after the PF. To mitigate motion sickness, PF participants received scopolamine prior to PF. To account for the scopolamine effects, 12 non-PF controls were scanned prior to and after scopolamine injection. Changes in functional connectivity were explored with the Intrinsic Connectivity Contrast (ICC). Seed-based analysis on the regions exhibiting localized changes was subsequently performed to understand the networks associated with the identified nodes. We found that the PF group was characterized by lower ICC scores in the right temporo-parietal junction (rTPJ), an area involved in multisensory integration and spatial tasks. The encompassed network revealed PF-related decreases in within- and inter-hemispheric anticorrelations between the rTPJ and the supramarginal gyri, indicating both altered vestibular and self-related functions. Our findings shed light on how the brain copes with gravity transitions, on gravity internalization and are relevant for the understanding of bodily self-consciousness.
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- 2017
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38. General Anesthesia: A Probe to Explore Consciousness
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Vincent Bonhomme, Cécile Staquet, Javier Montupil, Aline Defresne, Murielle Kirsch, Charlotte Martial, Audrey Vanhaudenhuyse, Camille Chatelle, Stephen Karl Larroque, Federico Raimondo, Athena Demertzi, Olivier Bodart, Steven Laureys, and Olivia Gosseries
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general anesthesia ,consciousness ,mechanisms ,brain function ,brain networks ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
General anesthesia reversibly alters consciousness, without shutting down the brain globally. Depending on the anesthetic agent and dose, it may produce different consciousness states including a complete absence of subjective experience (unconsciousness), a conscious experience without perception of the environment (disconnected consciousness, like during dreaming), or episodes of oriented consciousness with awareness of the environment (connected consciousness). Each consciousness state may potentially be followed by explicit or implicit memories after the procedure. In this respect, anesthesia can be considered as a proxy to explore consciousness. During the recent years, progress in the exploration of brain function has allowed a better understanding of the neural correlates of consciousness, and of their alterations during anesthesia. Several changes in functional and effective between-region brain connectivity, consciousness network topology, and spatio-temporal dynamics of between-region interactions have been evidenced during anesthesia. Despite a set of effects that are common to many anesthetic agents, it is still uneasy to draw a comprehensive picture of the precise cascades during general anesthesia. Several questions remain unsolved, including the exact identification of the neural substrate of consciousness and its components, the detection of specific consciousness states in unresponsive patients and their associated memory processes, the processing of sensory information during anesthesia, the pharmacodynamic interactions between anesthetic agents, the direction-dependent hysteresis phenomenon during the transitions between consciousness states, the mechanisms of cognitive alterations that follow an anesthetic procedure, the identification of an eventual unitary mechanism of anesthesia-induced alteration of consciousness, the relationship between network effects and the biochemical or sleep-wake cycle targets of anesthetic agents, as well as the vast between-studies variations in dose and administration mode, leading to difficulties in between-studies comparisons. In this narrative review, we draw the picture of the current state of knowledge in anesthesia-induced unconsciousness, from insights gathered on propofol, halogenated vapors, ketamine, dexmedetomidine, benzodiazepines and xenon. We also describe how anesthesia can help understanding consciousness, we develop the above-mentioned unresolved questions, and propose tracks for future research.
- Published
- 2019
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39. Environmental profile of ceramic tiles and their potential for improvement
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Almeida, Marisa Isabel, Dias, Ana Cláudia, Demertzi, Martha, and Arroja, Luís
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- 2016
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40. Cork stoppers supply chain: potential scenarios for environmental impact reduction
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Demertzi, Martha, Silva, Rui Pedro, Neto, Belmira, Dias, Ana Cláudia, and Arroja, Luís
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- 2016
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41. New measurement of the diffusion of carbon dioxide on non-porous amorphous solid water
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Jiao He, Paula Caroline Pérez Rickert, Tushar Suhasaria, Orianne Sohier, Tia Bäcker, Dimitra Demertzi, Gianfranco Vidali, and Thomas K. Henning
- Subjects
Chemical Physics (physics.chem-ph) ,Astrophysics - Solar and Stellar Astrophysics ,Physics - Chemical Physics ,Biophysics ,FOS: Physical sciences ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Instrumentation and Methods for Astrophysics (astro-ph.IM) ,Molecular Biology ,Solar and Stellar Astrophysics (astro-ph.SR) - Abstract
The diffusion of molecules on interstellar grain surfaces is one of the most important driving forces for the molecular complexity in the interstellar medium. Due to the lack of laboratory measurements, astrochemical modeling of grain surface processes usually assumes a constant ratio between the diffusion energy barrier and the desorption energy. This over-simplification inevitably causes large uncertainty in model predictions. We present a new measurement of the diffusion of CO$_2$ molecules on the surface of non-porous amorphous solid water (np-ASW), an analog of the ice mantle that covers cosmic dust grains. A small coverage of CO$_2$ was deposited onto an np-ASW surface at 40~K, the subsequent warming of the ice activated the diffusion of CO$_2$ molecules, and a transition from isolated CO$_2$ to CO$_2$ clusters was seen in the infrared spectra. To obtain the diffusion energy barrier and pre-exponential factor simultaneously, a set of isothermal experiments were carried out. The values for the diffusion energy barrier and pre-exponential factor were found to be $1300\pm110$~K and $10^{7.6\pm0.8}$~s$^{-1}$. A comparison with prior laboratory measurements on diffusion is discussed., 13 pages, 6 figures
- Published
- 2023
42. An Overview of Privacy Dimensions on Industrial Internet of Things (IIoT)
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Demertzi, Vasiliki, Demertzis, Stavros, and Demertzis, Konstantinos
- Subjects
FOS: Computer and information sciences ,Computer Science - Cryptography and Security ,Cryptography and Security (cs.CR) - Abstract
Thanks to rapid technological developments, new innovative solutions and practical applications of the Industrial Internet of Things (IIoT) are being created, upgrading the structures of many industrial enterprises. IIoT brings the physical and digital environment together with minimal human intervention and profoundly transforms the economy and modern business. Data flowing through IIoT feed artificial intelligence tools, which perform intelligent functions such as performance tuning of interconnected machines, error correction, and preventive maintenance. However, IIoT deployments are vulnerable to sophisticated security threats at various levels of the connectivity and communications infrastructure they incorporate. The complex and often heterogeneous nature of chaotic IIoT infrastructures means that availability, confidentiality and integrity are difficult to guarantee. This can lead to potential mistrust of network operations, concerns about privacy breaches or loss of vital personal data and sensitive information of network end-users. This paper examines the privacy requirements of an IIoT ecosystem in industry standards. Specifically, it describes the industry privacy dimensions of the protection of natural persons through the processing of personal data by competent authorities for the prevention, investigation, detection or prosecution of criminal offences or the execution of criminal penalties. In addition, it presents an overview of the state-of-the-art methodologies and solutions for industrial privacy threats. Finally, it analyses the privacy requirements and suggestions for an ideal secure and private IIoT environment.
- Published
- 2023
43. Neuroplasticity in F16 fighter jet pilots
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Radstake, Wilhelmina E., Jillings, Steven, Laureys, Steven, Demertzi, Athena, Sunaert, Stefan, Van Ombergen, Angelique, and Wuyts, Floris L.
- Subjects
Physiology ,Physiology (medical) ,Human medicine - Abstract
Exposure to altered g-levels causes unusual sensorimotor demands that must be dealt with by the brain. This study aimed to investigate whether fighter pilots, who are exposed to frequent g-level transitions and high g-levels, show differential functional characteristics compared to matched controls, indicative of neuroplasticity. We acquired resting-state functional magnetic resonance imaging data to assess brain functional connectivity (FC) changes with increasing flight experience in pilots and to assess differences in FC between pilots and controls. We performed whole-brain exploratory and region-of-interest (ROI) analyses, with the right parietal operculum 2 (OP2) and the right angular gyrus (AG) as ROIs. Our results show positive correlations with flight experience in the left inferior and right middle frontal gyri, and in the right temporal pole. Negative correlations were observed in primary sensorimotor regions. We found decreased whole-brain functional connectivity of the left inferior frontal gyrus in fighter pilots compared to controls and this cluster showed decreased functional connectivity with the medial superior frontal gyrus. Functional connectivity increased between the right parietal operculum 2 and the left visual cortex, and between the right and left angular gyrus in pilots compared to controls. These findings suggest altered motor, vestibular, and multisensory processing in the brains of fighter pilots, possibly reflecting coping strategies to altered sensorimotor demands during flight. Altered functional connectivity in frontal areas may reflect adaptive cognitive strategies to cope with challenging conditions during flight. These findings provide novel insights into brain functional characteristics of fighter pilots, which may be of interest to humans traveling to space.
- Published
- 2023
44. Assessing Annual Actual Evapotranspiration Based on Climate, Topography and Soil in Natural and Agricultural Ecosystems
- Author
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Kleoniki Demertzi, Vassilios Pisinaras, Emanuel Lekakis, Evangelos Tziritis, Konstantinos Babakos, and Vassilis Aschonitis
- Subjects
actual evapotranspiration ,reference evapotranspiration ,surface runoff ,surface slope ,percolation ,saturated hydraulic conductivity ,Science - Abstract
Simple formulas for estimating annual actual evapotranspiration (AET) based on annual climate data are widely used in large scale applications. Such formulas do not have distinct compartments related to topography, soil and irrigation, and for this reason may be limited in basins with high slopes, where runoff is the dominant water balance component, and in basins where irrigated agriculture is dominant. Thus, a simplistic method for assessing AET in both natural ecosystems and agricultural systems considering the aforementioned elements is proposed in this study. The method solves AET through water balance based on a set of formulas that estimate runoff and percolation. These formulas are calibrated by the results of the deterministic hydrological model GLEAMS (Groundwater Loading Effects of Agricultural Management Systems) for a reference surface. The proposed methodology is applied to the country of Greece and compared with the widely used climate-based methods of Oldekop, Coutagne and Turk. The results show that the proposed methodology agrees very well with the method of Turk for the lowland regions but presents significant differences in places where runoff is expected to be very high (sloppy areas and areas of high rainfall, especially during December–February), suggesting that the proposed method performs better due to its runoff compartment. The method can also be applied in a single application considering irrigation only for the irrigated lands to more accurately estimate AET in basins with a high percentage of irrigated agriculture.
- Published
- 2021
- Full Text
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45. Environmental performance of a cork floating floor
- Author
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Demertzi, Martha, Garrido, Ana, Dias, Ana Cláudia, and Arroja, Luis
- Published
- 2015
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46. Covert Cognition in Disorders of Consciousness: A Meta-Analysis
- Author
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Caroline Schnakers, Michaela Hirsch, Enrique Noé, Roberto Llorens, Nicolas Lejeune, Vigneswaran Veeramuthu, Sabrina De Marco, Athena Demertzi, Catherine Duclos, Ann-Marie Morrissey, Camille Chatelle, and Anna Estraneo
- Subjects
severe brain injury ,consciousness ,vegetative state ,minimally conscious state ,covert cognition ,cognitive motor dissociation ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Covert cognition in patients with disorders of consciousness represents a real diagnostic conundrum for clinicians. In this meta-analysis, our main objective was to identify clinical and demographic variables that are more likely to be associated with responding to an active paradigm. Among 2018 citations found on PubMed, 60 observational studies were found relevant. Based on the QUADAS-2, 49 studies were considered. Data from 25 publications were extracted and included in the meta-analysis. Most of these studies used electrophysiology as well as counting tasks or mental imagery. According to our statistical analysis, patients clinically diagnosed as being in a vegetative state and in a minimally conscious state minus (MCS−) show similar likelihood in responding to active paradigm and responders are most likely suffering from a traumatic brain injury. In the future, multi-centric studies should be performed in order to increase sample size, with similar methodologies and include structural and functional neuroimaging in order to identify cerebral markers related to such a challenging diagnosis.
- Published
- 2020
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47. Altered Brain Connectivity and Network Topological Organization in a Non-ordinary State of Consciousness Induced by Hypnosis.
- Author
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Panda, Rajanikant, Vanhaudenhuyse, Audrey, Piarulli, Andrea, Annen, Jitka, Demertzi, Athena, Alnagger, Naji, Chennu, Srivas, Laureys, Steven, Faymonville, Marie-Elisabeth, and Gosseries, Olivia
- Subjects
LARGE-scale brain networks ,HYPNOTISM ,CONSCIOUSNESS ,EYE muscles ,MIND-wandering - Abstract
Hypnosis has been shown to be of clinical utility; however, its underlying neural mechanisms remain unclear. This study aims to investigate altered brain dynamics during the non-ordinary state of consciousness induced by hypnosis. We studied high-density EEG in 9 healthy participants during eyes-closed wakefulness and during hypnosis, induced by a muscle relaxation and eyes fixation procedure. Using hypotheses based on internal and external awareness brain networks, we assessed region-wise brain connectivity between six ROIs (right and left frontal, right and left parietal, upper and lower midline regions) at the scalp level and compared across conditions. Data-driven, graph-theory analyses were also carried out to characterize brain network topology in terms of brain network segregation and integration. During hypnosis, we observed (1) increased delta connectivity between left and right frontal, as well as between right frontal and parietal regions; (2) decreased connectivity for alpha (between right frontal and parietal and between upper and lower midline regions) and beta-2 bands (between upper midline and right frontal, frontal and parietal, also between upper and lower midline regions); and (3) increased network segregation (short-range connections) in delta and alpha bands, and increased integration (long-range connections) in beta-2 band. This higher network integration and segregation was measured bilaterally in frontal and right parietal electrodes, which were identified as central hub regions during hypnosis. This modified connectivity and increased network integration–segregation properties suggest a modification of the internal and external awareness brain networks that may reflect efficient cognitive-processing and lower incidences of mind-wandering during hypnosis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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48. An Overview of Privacy Dimensions on the Industrial Internet of Things (IIoT).
- Author
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Demertzi, Vasiliki, Demertzis, Stavros, and Demertzis, Konstantinos
- Subjects
- *
INTERNET of things , *DIGITAL technology , *LITERATURE reviews , *PRIVACY , *ARTIFICIAL intelligence , *DATA privacy , *INTERNET privacy - Abstract
The rapid advancements in technology have given rise to groundbreaking solutions and practical applications in the field of the Industrial Internet of Things (IIoT). These advancements have had a profound impact on the structures of numerous industrial organizations. The IIoT, a seamless integration of the physical and digital realms with minimal human intervention, has ushered in radical changes in the economy and modern business practices. At the heart of the IIoT lies its ability to gather and analyze vast volumes of data, which is then harnessed by artificial intelligence systems to perform intelligent tasks such as optimizing networked units' performance, identifying and correcting errors, and implementing proactive maintenance measures. However, implementing IIoT systems is fraught with difficulties, notably in terms of security and privacy. IIoT implementations are susceptible to sophisticated security attacks at various levels of networking and communication architecture. The complex and often heterogeneous nature of these systems makes it difficult to ensure availability, confidentiality, and integrity, raising concerns about mistrust in network operations, privacy breaches, and potential loss of critical, personal, and sensitive information of the network's end-users. To address these issues, this study aims to investigate the privacy requirements of an IIoT ecosystem as outlined by industry standards. It provides a comprehensive overview of the IIoT, its advantages, disadvantages, challenges, and the imperative need for industrial privacy. The research methodology encompasses a thorough literature review to gather existing knowledge and insights on the subject. Additionally, it explores how the IIoT is transforming the manufacturing industry and enhancing industrial processes, incorporating case studies and real-world examples to illustrate its practical applications and impact. Also, the research endeavors to offer actionable recommendations on implementing privacy-enhancing measures and establishing a secure IIoT ecosystem. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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49. Synthesis of a palladium complex with a β-d-glucopyranosyl-thiosemicarbazone and its application in the Suzuki–Miyaura coupling of aryl bromides with phenylboronic acid
- Author
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Tenchiu, Alia-Cristina, Ventouri, Iro-Konstantina, Ntasi, Georgia, Palles, Dimitrios, Kokotos, George, Kovala-Demertzi, Dimitra, and Kostas, Ioannis D.
- Published
- 2015
- Full Text
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50. Contribution to the development of product category rules for ceramic bricks
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Almeida, Marisa Isabel, Dias, Ana Cláudia, Demertzi, Martha, and Arroja, Luís
- Published
- 2015
- Full Text
- View/download PDF
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