423 research outputs found
The effect of expectation on facilitation of colour/form conjunction tasks by TMS over area V5
In an earlier paper, we reported task-specific impairments and improvements caused by applying TMS over cortical visual area V5 [Proceedings of the Royal Society of London B 265 (1998) 537]. The phenomenon is further investigated in the present study using two of the previous tasks: a motion/form conjunction in which TMS impaired performance and a colour/form conjunction in which performance was enhanced with TMS. In the earlier experiment, subjects were presented with blocks of trials of one task type perhaps allowing some of the observed effects to arise from knowing the type of stimulus to be discriminated. When blocks of trials consisted of randomly mixed moving/form and colour/form conjunction tasks, TMS over V5 still impaired target-present responses for the moving/form conjunction, but the facilitation seen for colour/form conjunction target-present responses disappeared. We suggest that the competitive inhibition postulated between visual movement areas and colour areas in the brain, in our previous paper, are subject to expectation or knowledge of forthcoming stimulus type
double dissociation between the extrastriate body area and the posterior superior temporal sulcus during biological motion perception converging evidence from tms and fmri
Our brains engage numerous regions when exposed to biological motion, with the posterior superior temporal sulcus (pSTS) being the primary locus. The exact roles of hMT+ and the extrastriate body area (EBA) remain unclear. Here, we set out to determine the specific roles of pSTS and EBA during biological motion perception, focusing on walker orientation and walking direction. To obtain converging evidence, we conducted separate TMS and fMRI experiments within the same subjects (N = 12). Two separate tasks were used in the TMS study: walker orientation probing form processing and walking direction probing motion/sequence processing. Task performance was compared before and after applying repetitive offline TMS (1 Hz) over EBA and pSTS (based on fMRI-guided stereotaxy). In the fMRI study, EBA and pSTS were mapped in separate scans using standard localizers. Subsequently, runs with point-light walkers were subjected to MVPA, determining the amount of static (orientation) and dynamic (direction) information p..
Chronic kidney disease: Which role for xanthine oxidoreductase activity and products?
The present review explores the role of xanthine oxidoreductase (XOR) in the development and progression of chronic kidney disease (CKD). Human XOR is a multi-level regulated enzyme, which has many physiological functions, but that is also implicated in several pathological processes. The main XOR activities are the purine catabolism, which generates uric acid, and the regulation of cell redox state and cell signaling, through the production of reactive oxygen species. XOR dysregulation may lead to hyperuricemia and oxidative stress, which could have a pathogenic role in the initial phases of CKD, by promoting cell injury, hypertension, chronic inflammation and metabolic derangements. Hypertension is common in CKD patients and many mechanisms inducing it (upregulation of renin-angiotensin-aldosterone system, endothelial dysfunction and atherosclerosis) may be influenced by XOR products. High XOR activity and hyperuricemia are also risk factors for obesity, insulin resistance, type 2 diabetes and metabolic syndrome that are frequent CKD causes. Moreover, CKD is common in patients with gout, which is characterized by hyperuricemia, and in patients with cardiovascular diseases, which are associated with hypertension, endothelial dysfunction and atherosclerosis. Although hyperuricemia is undoubtedly related to CKD, controversial findings have been hitherto reported in patients treated with urate-lowering therapies
Ricin: An ancient story for a timeless plant toxin
The castor plant (Ricinus communis L.) has been known since time immemorial in traditional medicine in the pharmacopeia of Mediterranean and eastern ancient cultures. Moreover, it is still used in folk medicine worldwide. Castor bean has been mainly recommended as anti-inflammatory, anthelmintic, anti-bacterial, laxative, abortifacient, for wounds, ulcers, and many other indications. Many cases of human intoxication occurred accidentally or voluntarily with the ingestion of castor seeds or derivatives. Ricinus toxicity depends on several molecules, among them the most important is ricin, a protein belonging to the family of ribosome-inactivating proteins. Ricin is the most studied of this category of proteins and it is also known to the general public, having been used for several biocrimes. This manuscript intends to give the reader an overview of ricin, focusing on the historical path to the current knowledge on this protein. The main steps of ricin research are here reported, with particular regard to its enzymatic activity, structure, and cytotoxicity. Moreover, we discuss ricin toxicity for animals and humans, as well as the relation between bioterrorism and ricin and its impact on environmental toxicity. Ricin has also been used to develop immunotoxins for the elimination of unwanted cells, mainly cancer cells; some of these immunoconjugates gave promising results in clinical trials but also showed critical limitation
Steady-state visual evoked potentials and phase synchronization in migraine
We investigate phase synchronization in EEG recordings from migraine
patients. We use the analytic signal technique, based on the Hilbert transform,
and find that migraine brains are characterized by enhanced alpha band phase
synchronization in presence of visual stimuli. Our findings show that migraine
patients have an overactive regulatory mechanism that renders them more
sensitive to external stimuli.Comment: 4 page
Effect of maize, rumen-protected fat and whey permeate on energy utilisation and milk fat composition in lactating goats
The efficiency of utilisation of diets with different proportions of energy sources (starch, fat, lactose) was studied with three pairs of lactating Saanen goats; the animals were fed, in a Latin square design, 3 silage-based diets containing (on DM basis) the following energy sources: 32% maize meal (diet M); 4.7% rumen-protected fat (Megalac®) and 23.5% maize meal (diet F); 9.8% milk whey permeate powder and 22.3% maize meal (diet W). During each of the three experimental periods, 8 days of total collection balance trials were conducted during which goats were allocated for 72 h (three 24 h cycles) in open circuit respiration chambers to determine methane and heat production and, hence, the energy balance. Diet F, in comparison with diets M and W, significantly increased the milk fat content (4.13 vs 3.11 and 3.14%, P<0.001) and the 4%-FCM yield (3367 vs 2927 and 3055 g/d, P<0.01 and P<0.05, respectively), while no relevant changes were observed for milk protein content and yield. Energy digestibility was equal in diets F and W. Megalac® did not decrease fibre digestibility. The partition of the gross energy intake (EI) differed significantly between diets: diet M had lower DE (72.4 vs 74.3 and 74.3%; P<0.01) and ME (62.1 vs 64.7 and 63.5%; P<0.05) in comparison with diets F and W, respectively. Energy lost as methane was not significantly decreased by the inclusion of rumen- protected fat in the diet, although a trend for a reduction of methanogenesis was observed. Heat production deter- mined by treatment F was lower in comparison with the other treatments. This difference was almost significant (P=0.056) when expressed as a percentage of the ME. Milk energy output increased significantly (+12%, P<0.001) by including fat in the diet, as compared with treatments M and W: 21.4 vs 19.1 and 19.0% of the EI. The net ener- gy content of the protected fat was 27.94 MJ NEl/kg DM (+340% vs maize meal); its kl value resulted 0.77. The corresponding values for whey permeate were 7.76 MJ NEl/kg DM (-5% vs maize meal) and 0.50, respectively. Summarizing, the efficiency of energy utilization in diet M was significantly lower in comparison with the other two diets in terms of digestibility and metabolisability, while its NEl content was similar to that of diet W. On the other hand, diet F had a significantly higher ME (P<0.01) and NEl (P<0.05) as compared to the other two diets. Diet F greatly influenced the fatty acid composition of the milk fat with less short (-30%) and medium (-33%) chain fatty acids and more (+18%) long chain fatty acids. In conclusion, whey permeate and even more Megalac® can be suc- cessfully used as feed ingredients in the diet of highly productive lactating goats, but the economical convenience of their utilisation must be evaluated based on the market values of feedstuffs
Oral rehabilitation with implant-supported overdenture (ISO) in four children with ectodermal dysplasia
Polymorphisms of microsomal epoxyde hydrolase gene and severity of HCV-related liver disease.
Bollettino Sismico Italiano 2011
Questo lavoro illustra lo stato della Rete Sismica Nazionale Italiana (RSNI) e le principali caratteristiche della
sismicità in Italia nell’anno 2011. In tale anno, tramite i dati raccolti dalla RSNI, sono stati localizzati 16499
eventi registrati da 359 stazioni appartenenti sia all’INGV, sia ad altre reti locali e regionali connesse in
tempo reale al Centro Nazionale Terremoti (CNT) di Roma. La magnitudo minima di completezza del Bollettino
Sismico Italiano (BSI) è ML 1.5. La magnitudo massima è stata registrata per un evento localizzato nella pianura
padano veneta (ML 4.8). Nella sismicità italiana del 2011 sono state individuate 46 sequenze sismiche rilevanti; tra
esse riveste particolare interesse la sequenza nel Montefeltro: iniziata a fine maggio e durata diversi mesi, essa
comprende due eventi di magnitudo ML 4.0. La sequenza del Pollino, iniziata nel 2009 e proseguita a più riprese fino
al 25 ottobre 2012 con un evento di magnitudo MW 5.2, presenta a inizio 2011 un aumento della sismicità che è
culminato con l’evento maggiore di quell’anno (ML 3.6). L’analisi del BSI ha inoltre permesso di individuare una
nuova area caratterizzata da eventi di origine antropica (esplosioni in cava) che si aggiunge alle 16 già rilevate negli
anni precedenti. In questo lavoro vengono analizzati anche i segnali prodotti da frane di crollo, molto diffuse nel
nostro paese lungo gli archi montani alpini e appenninici
Bollettino Sismico Italiano 2009
Questo lavoro illustra lo stato della Rete Sismica Nazionale Italiana e descrive la sismicità italiana nell’anno
2009. Vengono evidenziate le principali sequenze sismiche occorse durante l’anno, con particolare riguardo
alla sequenza sismica dell’aquilano-reatino. Nel 2009 la Rete Sismica Nazionale dell’INGV ha registrato
circa 26000 terremoti avvenuti sul territorio nazionale e nelle aree limitrofe, che sono stati analizzati e localizzati
dal gruppo di analisti sismologi che si occupano della redazione del Bollettino Sismico Italiano (BSI). La magnitudo
minima di completezza Mc del BSI 2009, ovvero la soglia di magnitudo minima media calcolata su tutto il territorio
nazionale, è risultata pari a ML 1.6 (il dato del BSI 2008 si attestava sul valore di ML 2.1).
Il numero di stazioni sismiche attive (Rete Nazionale e reti locali) nel corso del 2009 è stato di 305 (279 nel 2008).
Viene fornita infine una stima del numero e della magnitudo di eventi di origine antropica (esplosioni) presenti
nel BSI 2009.
This paper describes the status of the Italian National Seismic Network and the Italian seismicity in year 2009. We
outline the main seismic sequences that occurred during the year, with particular emphasis on the L’Aquila-Rieti seismic
period. The INGV National Seismic Network recorded about 26000 earthquakes in Italy and neighboring areas during
2009, which were analyzed and localized by the seismology group of analysts involved in the publication of the Italian Seismic
Bulletin (BSI). The minimum magnitude of completeness Mc of the BSI 2009 is ML 1.6 (ML 2.1 in the BSI 2008).
The number of active seismic stations during 2009 was 305 (279 in 2008).
We provide an estimate of the number and magnitude of anthropic events (quarry-blasts) included in the BSI 2009
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