993 research outputs found
Disruption of transfer entropy and inter-hemispheric brain functional connectivity in patients with disorder of consciousness
Severe traumatic brain injury can lead to disorders of consciousness (DOC)
characterized by deficit in conscious awareness and cognitive impairment
including coma, vegetative state, minimally consciousness, and lock-in
syndrome. Of crucial importance is to find objective markers that can account
for the large-scale disturbances of brain function to help the diagnosis and
prognosis of DOC patients and eventually the prediction of the coma outcome.
Following recent studies suggesting that the functional organization of brain
networks can be altered in comatose patients, this work analyzes brain
functional connectivity (FC) networks obtained from resting-state functional
magnetic resonance imaging (rs-fMRI). Two approaches are used to estimate the
FC: the Partial Correlation (PC) and the Transfer Entropy (TE). Both the PC and
the TE show significant statistical differences between the group of patients
and control subjects; in brief, the inter-hemispheric PC and the
intra-hemispheric TE account for such differences. Overall, these results
suggest two possible rs-fMRI markers useful to design new strategies for the
management and neuropsychological rehabilitation of DOC patients.Comment: 25 pages; 4 figures; 3 tables; 1 supplementary figure; 4
supplementary tables; accepted for publication in Frontiers in
Neuroinformatic
Vakituisen henkilöstön nÀkemyksiÀ sijaisista pÀivÀkodin pedagogisessa toiminnassa
TiivistelmÀ. Pro graduni tavoitteena on selvittÀÀ, millaisia vaikutuksia sijaisilla on pÀivÀkodin arjen pedagogiseen toimintaan. Tutkimuksen aineisto on kerÀtty varhaiskasvatuksen opettajilta ja lastenhoitajilta. Teoreettinen osuus kÀsittelee varhaiskasvatuksen pedagogiikkaa, pedagogista johtajuutta sekÀ varhaiskasvatuksen toimintakulttuuria ja henkilöstörakennetta. Tutkimukseni aineisto on kerÀtty kevÀÀllÀ 2019 kvalitatiivisen tutkimuksen jatkokurssilla. Tutkimus on toteutettu sÀhköisellÀ kyselylomakkeella ja jaettu sosiaalisessa mediassa. Tutkimukseen osallistui vastaajia (N=155) eri puolilta Suomea.
Tutkimuksessani kÀytÀn grounded theory -analyysimenetelmÀÀ, joka on yksi laadullisen tutkimuksen menetelmistÀ. SiinÀ tarkastellaan aineistoa aineistolÀhtöisesti. AnalyysimenetelmÀ koostuu kolmesta askeleesta: avoimesta koodauksesta, aksiaalinen koodauksesta sekÀ valikoivasta koodauksesta. Lopulta muodostetaan teoria tulosten perusteella.
Tutkimukseni idea lÀhti omista kokemuksistani sijaisena olemisesta. Sijaisia ei ole paljoakaan aiemmin tutkittu, joten tutkimukseni tuo pedagogisesta nÀkökulmasta uutta puolta varhaiskasvatuksen kentÀlle. Sijaiset ovat nykyÀÀn iso osa pÀivÀkotien toimintaa, joten tutkimukseni aihe on ajankohtainen. Tutkimuksessani tarkastelen varhaiskasvatuksen henkilöstön pedagogista toimintaa osana sijaisten kanssa toimimista.
Tutkimukseni osoittaa selkeÀn sijaistarpeen pÀivÀkotien arjessa. Sijaiset vaikuttavat teoriani mukaan kahdella tasolla: hallinnollisella tasolla ja arjen tasolla. Sijaisia tarvitaan avuksi ja silmÀpareiksi ryhmiin. MitÀ tutumpi sijainen on, sitÀ paremmin hÀn todennÀköisesti asettuu pÀivÀkodin arkeen ja ryhmÀÀn. YleensÀ pÀivÀkodin johtaja hankkii sijaiset, ja ryhmÀ perehdyttÀÀ heidÀt. TÀmÀ on pois lapsiryhmÀltÀ.
Tutkimukseni perusteella voidaan todeta, ettÀ pÀivÀkotien vakituisella henkilöstöllÀ on vahva pedagoginen osaaminen. SijaisjÀrjestelyt ovat kuitenkin monelta osin epÀselvÀt, joten niitÀ olisi kehitettÀvÀ. NÀin pedagoginen toiminta toteutuu parhaalla mahdollisella tavalla vakituisen henkilöstön poissa ollessa
Modeling of Neuronal Growth In Vitro: Comparison of Simulation Tools NETMORPH and CX3D
We simulate the growth of neuronal networks using the two recently published tools, NETMORPH and CX3D. The goals of the work are (1) to examine and compare the simulation tools, (2) to construct a model of growth of neocortical cultures, and (3) to characterize the changes in network connectivity during growth, using standard graph theoretic methods. Parameters for the neocortical culture are chosen after consulting both the experimental and the computational work presented in the literature. The first (three) weeks in culture are known to be a time of development of extensive dendritic and axonal arbors and establishment of synaptic connections between the neurons. We simulate the growth of networks from day 1 to day 21. It is shown that for the properly selected parameters, the simulators can reproduce the experimentally obtained connectivity. The selected graph theoretic methods can capture the structural changes during growth.Peer reviewe
Time Dependence of Charge Transfer Processes in Diamond Studied with Positrons
We have developed a method called optical transient positron spectroscopy and apply it to study the optically induced carrier trapping and charge transfer processes in natural brown type IIa diamond. By measuring the positron lifetime with continuous and pulsed illumination, we present an estimate of the optical absorption cross section of the vacancy clusters causing the brown color. The vacancy clusters accept electrons from the valence band in the absorption process, giving rise to photoconductivity.Peer reviewe
Effects of oral lycopene supplementation on vascular function in patients with cardiovascular disease and healthy volunteers: a randomised controlled trial.
AIMS: The mechanisms by which a 'Mediterranean diet' reduces cardiovascular disease (CVD) burden remain poorly understood. Lycopene is a potent antioxidant found in such diets with evidence suggesting beneficial effects. We wished to investigate the effects of lycopene on the vasculature in CVD patients and separately, in healthy volunteers (HV). METHODS AND RESULTS: We randomised 36 statin treated CVD patients and 36 healthy volunteers in a 2â¶1 treatment allocation ratio to either 7 mg lycopene or placebo daily for 2 months in a double-blind trial. Forearm responses to intra-arterial infusions of acetylcholine (endothelium-dependent vasodilatation; EDV), sodium nitroprusside (endothelium-independent vasodilatation; EIDV), and NG-monomethyl-L-arginine (basal nitric oxide (NO) synthase activity) were measured using venous plethysmography. A range of vascular and biochemical secondary endpoints were also explored. EDV in CVD patients post-lycopene improved by 53% (95% CI: +9% to +93%, Pâ=â0.03 vs. placebo) without changes to EIDV, or basal NO responses. HVs did not show changes in EDV after lycopene treatment. Blood pressure, arterial stiffness, lipids and hsCRP levels were unchanged for lycopene vs. placebo treatment groups in the CVD arm as well as the HV arm. At baseline, CVD patients had impaired EDV compared with HV (30% lower; 95% CI: -45% to -10%, Pâ=â0.008), despite lower LDL cholesterol (1.2 mmol/L lower, 95% CI: -1.6 to -0.9 mmol/L, P<0.001). Post-therapy EDV responses for lycopene-treated CVD patients were similar to HVs at baseline (2% lower, 95% CI: -30% to +30%, Pâ=â0.85), also suggesting lycopene improved endothelial function. CONCLUSIONS: Lycopene supplementation improves endothelial function in CVD patients on optimal secondary prevention, but not in HVs. TRIAL REGISTRATION: ClinicalTrials.gov NCT01100385
ConsequĂȘncias metodolĂłgicas das formulaçÔes 'as if': como a abordagem evolucionĂĄria sugere uma interpretação realista da economia
Pyrazine-Fused Triterpenoids Block the TRPA1 Ion Channel in Vitro and Inhibit TRPA1-Mediated Acute Inflammation in Vivo
TRPA1 is a nonselective cation channel, most famously expressed in nonmyelinated nociceptors. In addition to being an important chemical and mechanical pain sensor, TRPA1 has more recently appeared to have a role also in inflammation. Triterpenoids are natural products with anti-inflammatory and anticancer effects in experimental models. In this paper, 13 novel triterpenoids were created by synthetically modifying betulin, an abundant triterpenoid of the genus Betula L., and their TRPA1-modulating properties were examined. The Fluo 3-AM protocol was used in the initial screening, in which six of the 14 tested triterpenoids inhibited TRPA1 in a statistically significant manner. In subsequent whole-cell patch clamp recordings, the two most effective compounds (pyrazine-fused triterpenoids 8 and 9) displayed a reversible and dose- and voltage-dependent effect to block the TRPA1 ion channel at submicromolar concentrations. Interestingly, the TRPA1 blocking action was also evident in vivo, as compounds 8 and 9 both alleviated TRPA1 agonist-induced acute paw inflammation in mice. The results introduce betulin-derived pyrazine-fused triterpenoids as promising novel antagonists of TRPA1 that are potentially useful in treating diseases with a TRPA1-mediated adverse component
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