Search results for "P3"
showing 10 items of 786 documents
The effects of 8-weeks Mindfulness-Based Stress Reduction program on cognitive control: an EEG study
2019
Objectives: Mindfulness practice can enhance different aspects of attentional functions, such as the ability to sustain the attentional focus over time. However, it is still unclear whether this practice might indeed impact higher cognitive functions, such as control mechanisms that allow the appropriate and flexible allocation of attentional resources. In this longitudinal study, changes associated with a mindfulness-based stress reduction (MBSR) program were investigated, with a focus on proactive and reactive cognitive control mechanisms, namely, the ability to maintain task-relevant information and to prepare in advance the response, and the ability to promptly adjust overlearned behavi…
P3HT plānu kārtiņu īpašību pētījumi 3D printētu termoelektrisko ierīču pielietojumiem
2019
Šajā darbā tika veikti pētījumi ar poli (3-heksiltiofēna) (P3HT) plānajām kārtiņām ar mērķi novērtēt šī materiāla pielietojamību 3D printētās termoelektriskās ierīcēs. Darbā tika pētītas tīras dažādu polimerizāciju pakāpes P3HT plānās kārtiņas un kārtiņas, kas ir dopētas ar (2,3,5,6-Tetrafluoro-2,5-cikloheksadiēn-1,4-dilidēn)-dimalonodinitrilu (F4TCNQ). Šīm kārtiņām tika noteikta elektrovadītspēja, Zēbeka koeficienti kā arī jaudas faktora vērtības. Lai varētu novērtēt šo vielu pielietojamību 3D printēšanai, to veidotās plānās kārtiņas tika karsētas un noteikti to raksturojošie koeficienti pēc katras karsēšanas. Šī karsēšana simulē apstākļus, kādiem tiktu pakļauti materiāli 3D printēšanas pr…
Synaptic scaling generically stabilizes circuit connectivity
2011
Neural systems regulate synaptic plasticity avoiding overly strong growth or shrinkage of the connections, thereby keeping the circuit architecture operational. Accordingly, several experimental studies have shown that synaptic weights increase only in direct relation to their current value, resulting in reduced growth for stronger synapses [1]. It is, however, difficult to extract from these studies unequivocal evidence about the underlying biophysical mechanisms that control weight growth. The theoretical neurosciences have addressed this problem by exploring mechanisms for synaptic weight change that contain limiting factors to regulate growth [2]. The effectiveness of these mechanisms i…
Mining of new insecticidal protein genes plus determination of the insecticidal spectrum and mode of action of Bacillus thuringiensis Vip3Ca protein
2019
Bacillus thuringiensis és un bacteri que pertany al grup de Bacillus cereus i produeix una gran varietat de proteïnes insecticides juntament amb altres factors de virulència que contribueixen a la seva patogenicitat. Bacillus thuringiensis s'ha considerat com el agent bioinsecticida amb més èxit durant el segle passat. Actualment, és àmpliament utilitzat com agent microbià per a les principals plagues d'insectes com a formulat (selecció de aïllats de B. thuringiensis escollits per la seua combinació de proteïnes insecticides present en el cristall parasporal) o mitjançant l’expressió de les proteïnes insecticides (cultius Bt) en plantes d’interès agronòmic (dacsa, cotó, soja, etc.). En quan…
Shedding of the amyloid precursor protein-like protein APLP2 by disintegrin-metalloproteinases
2005
Cleavage of the amyloid precursor protein (APP) within the amyloid-beta (Aβ) sequence by the α-secretase prevents the formation of toxic Aβ peptides. It has been shown that the disintegrin-metalloproteinases ADAM10 and TACE (ADAM17) act as α-secretases and stimulate the generation of a soluble neuroprotective fragment of APP, APPsα. Here we demonstrate that the related APP-like protein 2 (APLP2), which has been shown to be essential for development and survival of mice, is also a substrate for both proteinases. Overexpression of either ADAM10 or TACE in HEK293 cells increased the release of neurotrophic soluble APLP2 severalfold. The strongest inhibition of APLP2 shedding in neuroblastoma c…
Constitutive and regulated α-secretase cleavage of Alzheimer’s amyloid precursor protein by a disintegrin metalloprotease
1999
Amyloid β peptide (Aβ), the principal proteinaceous component of amyloid plaques in brains of Alzheimer’s disease patients, is derived by proteolytic cleavage of the amyloid precursor protein (APP). Proteolytic cleavage of APP by a putative α-secretase within the Aβ sequence precludes the formation of the amyloidogenic peptides and leads to the release of soluble APPsα into the medium. By overexpression ofa disintegrinandmetalloprotease (ADAM), classified as ADAM 10, in HEK 293 cells, basal and protein kinase C-stimulated α-secretase activity was increased severalfold. The proteolytically activated form of ADAM 10 was localized by cell surface biotinylation in the plasma membrane, but the m…
Implicación de los receptores TLR4 en el daño cerebral causado por el consumo de alcohol
2012
El abuso de alcohol puede causar daño cerebral y en ciertos casos cursa con neurodegeneración, aunque los mecanismos moleculares de estos efectos se desconocen. El Sistema Nervioso Central (SNC) ha sido considerado, hasta muy recientemente, como un sistema inmunológicamente privilegiado (Galea et al., 2007). Sin embargo, estudios de los últimos años indican que el cerebro coordina y regula numerosos aspectos de la respuesta inmune innata, y que la inflamación representa un factor crítico y esencial para muchas enfermedades del SNC, como son las enfermedades neurodegenerativas (Wild et al., 2008). Igualmente, la respuesta del sistema inmune innato también desempeña un papel crucial en el dañ…
Role of Adrenomedullin in LSP-mediated lung injury
2014
2016
The flexible access to information in working memory is crucial for adaptive behavior. It is assumed that this is realized by switching the focus of attention within working memory. Switching of attention is mirrored in the P3a component of the human event-related brain potential (ERP) and it has been argued that the processes reflected by the P3a are also relevant for selecting information within working memory. The aim of the present study was to further evaluate whether the P3a mirrors genuine switching of attention within working memory by applying an object switching task: Participants updated a memory list of four digits either by replacing one item with another digit or by processing…
2013
Distraction of goal-oriented performance by a sudden change in the auditory environment is an everyday life experience. Different types of changes can be distracting, including a sudden onset of a transient sound and a slight deviation of otherwise regular auditory background stimulation. With regard to deviance detection, it is assumed that slight changes in a continuous sequence of auditory stimuli are detected by a predictive coding mechanisms and it has been demonstrated that this mechanism is capable of distracting ongoing task performance. In contrast, it is open whether transient detection – which does not rely on predictive coding mechanisms – can trigger behavioral distraction, too…