Evidence suggests that G alpha(q/11) is more sensitive to the eff

Evidence suggests that G alpha(q/11) is more sensitive to the effects of aging relative to other G alpha-subunits, including G alpha(o). To test this hypothesis, the functionality of G alpha(q/11) and G alpha(o) were compared in the hippocampus of young (6 months) and aged (24 months) F344 x BNF1 hybrid rats assessed for spatial learning ability. Basal GTP gamma S-binding

to G alpha(q/11) was significantly elevated in aged rats relative to young and but not reliably associated with spatial learning. find more mAChR stimulation of G alpha(q/11) with oxotremorine-M produced equivocal GTP gamma S-binding between age groups although values tended to be lower in the aged hippocampus and were inversely related to basal activity. Downstream G alpha(q/11) function was measured in hippocampal subregion CA1 by determining changes in [Ca2+](i) after mAChR and mGluR (DHPG) stimulation. mAChR-stimulated peak

change in [Ca2+](i); was lower in aged CA1 relative to young while mGluR-mediated integrated [Ca2+](i) responses tended to be larger in aged. GPCR modulation of [Ca2+](i); was observed to depend on intracellular selleck products stores to a greater degree in aged than young. In contrast, measures of G alpha(o)-mediated GTP gamma S-binding were stable across age, including basal, mAChR-, GABA(B)R (baclofen)-stimulated levels. Overall, the data indicate that aging selectively selleck screening library modulates the activity of G alpha(q/11) within the hippocampus leading to deficient modulation of [Ca2+](i) following stimulation of mAChRs but these changes are not related to spatial learning. (C) 2013 Elsevier Ltd. All rights reserved.”
“Vector-borne diseases are common in nature and can have a large impact on humans, livestock and crops. Biological control of vectors using natural enemies or competitors can reduce

vector density and hence disease transmission. However, the indirect interactions inherent in host-vector disease systems make it difficult to use traditional pest control theory to guide biological control of disease vectors. This necessitates a conceptual framework that explicitly considers a range of indirect interactions between the host-vector disease system and the vector’s biological control agent. Here we conduct a comparative analysis of the efficacy of different types of biological control agents in controlling vector-borne diseases. We report three key findings. First, highly efficient predators and parasitoids of the vector prove to be effective biological control agents, but highly virulent pathogens of the vector also require a high transmission rate to be effective. Second, biocontrol agents can successfully reduce long-term host disease incidence even though they may fail to reduce long-term vector densities.

Tumor uptake was always higher than the radioactivity in the bloo

Tumor uptake was always higher than the radioactivity in the blood and muscle, with good tumor retention and good tumor-to-blood and tumor-to-muscle ratios, indicating the potential of these agents for targeting tumors in vivo.

Conclusions: The combination of favorable in vitro and in vivo properties may render these BN peptides as potential candidates for targeting BN/GRP receptor-positive tumors. They deserve further evaluation to determine their real strength. The present data indeed provide useful information regarding peptide structure-pharmacologic activity relationship, which might be useful in designing and developing new BN-like peptides for efficient targeting of tumors in vivo.

(C) 2012 Elsevier Inc. All rights reserved.”
“It is generally accepted that the principal check details resident progenitor underlying regenerative capacity in skeletal muscle is the satellite Quisinostat price cell. Satellite cells are present throughout life even though

regenerative capacity declines with age and disease. Recently, other stem cell populations have been identified that can participate in muscle growth and regeneration. These cells may provide therapeutically useful sources of muscle stem cells as an alternative to satellite cells; however, the roles of these nonsatellite cell populations during muscle homeostasis, regeneration, and aging are unclear. Here, we discuss how the stem cell neighborhood influences satellite cell behavior and bring together recent discoveries DNA ligase pertaining to a wide variety of adult stem cells, including muscle stem cells and their niche.”
“The ketamine (ket) model reflects features of schizophrenia as well as secondary symptoms such as altered pain sensitivity.

In the present study, we investigated the effect of subchronic oral treatment with haloperidol (hal, 0.075 mg/kg) and risperidone (ris, 0.2 mg/kg) on altered pain perception and locomotor activity in this model.

In reaction to 5 mg/kg morphine, ket pretreated animals showed a diminished analgesic response. Hal had no analgesic effect per se, but the compound normalised the analgesic

reaction to morphine in the ket pretreated animals. The effect of ris was complex. First, there was no analgesic effect per se, and control animals showed a dose-dependent increase in the analgesic index after morphine injection. In the ket group treated with ris, the analgesic response to 5 mg/kg morphine was attenuated and in response to 10 mg/kg analgesia was comparable with that measured in controls. The reduced analgesic effect was not due to pharmacokinetic differences in morphine metabolism. After administration via drinking water in saline-injected control animals, the hal blood serum concentration was 2.6 +/- 0.45 ng/ml. In ket-injected animals, the mean serum concentration of hal amounted to 1.2 +/- 0.44 ng/ml. In the experiment using ris, animals in the control group had higher ris serum concentrations compared with ket-injected animals.


Logistic this website regression analysis related baseline characteristics to both operative mortality and a composite of mortality and major morbidity within 30 days. Points were assigned to each risk factor, and estimated risk was obtained by averaging events for all patients having the same number of points.

Results: Overall unadjusted mortality was 8.2%, and complications occurred in 53%. Significant preoperative risk factors for mortality (associated points) were as follows: emergency, salvage status, or cardiogenic shock (17), preoperative hemodialysis, renal failure, or creatinine level less than 2.0 (12),

preoperative inotropic or balloon pump support (10), active (vs treated) endocarditis (10), multiple valve involvement (9), insulin-dependent diabetes (8), arrhythmia (8), previous cardiac surgery (7), urgent status without cardiogenic shock (6), non-insulin-dependent diabetes (6), hypertension (5), and chronic lung disease (5), with a C statistic of 0.7578 (all P < .001). Risk-adjusted mortality and major morbidity were unchanged over the course of the study.

In the entire data set, mortality was better if “”any valve”" was repaired (odds ratio 0.76; P = .0023).

Conclusions: Operative mortality for surgically treated infective endocarditis is substantially lower than reported in-hospital mortality rates for infective endocarditis. The described risk scoring system will inform clinical decision-making in these complex patients. (J click here Thorac Cardiovasc Surg 2011;141:98-106)”
“Objective: Limited exposure and visualization and technical complexity have affected resident training in mitral valve surgery. We propose simulation-based learning to improve skill acquisition in mitral valve surgery.

Methods: After reviewing instructional video recordings of mitral annuloplasty in porcine and plastic models, 11 residents (6 integrated and 5 traditional) performed porcine model mitral annuloplasty. Video-recorded performance was reviewed by attending surgeon providing audio formative feedback

superimposed on video recordings; recordings were returned to residents for review. After 3-week practice with plastic model, Danusertib in vivo residents repeated porcine model mitral annuloplasty. Performance assessments initially (prefeedback) and at 3 weeks (postfeedback) were based on review of video recordings on 5-point rating scale (5, good; 3, average; 1, poor) of 11 components. Ratings were averaged for composite score.

Results: Time to completion improved from mean 31 +/- 9 minutes to 25 +/- 6 minutes after 3-week practice (P = .03). At 3 weeks, improvement in technical components was achieved by all residents, with prefeedback scores varying from 2.4 +/- 0.6 for needle angles to 3.0 +/- 0.5 for depth of bites and postfeedback scores of 3.1 +/- 0.8 for tissue handling to 3.6 +/- 0.8 for suture management and tension (P <= .001). Interrater reliability was greater than 0.8.

New identification tools targeting a rpoB gene fragment located b

New identification tools targeting a rpoB gene fragment located between positions 2300 and 3300 have been developed recently. Therefore, inclusion of the rpoB gene sequence would be useful when describing new bacterial species.”
“Introduction: Tc-99m-TMEOP is a novel heart perfusion radiotracer exhibiting high initial and persistent heart uptake associated with rapid blood and liver clearance. This study aimed at determining the mechanisms of myocardial localization and fast

liver clearance of Tc-99m-TMEOP.

Methods: Subcellular distribution of Tc-99m-TMEOP was determined in excised rat heart tissue Silmitasertib nmr by differential centrifugation. The effect of cyclosporin A on the pharmacokinetic behaviour of Tc-99m-TMEOP was evaluated by both ex vivo biodistribution and in vivo planar imaging studies.

Results: Subcellular distribution studies showed that more than 73% of Tc-99m-TMEOP was associated with the mitochondrial fraction. Comparison with subcellular distribution of Tc-99m-sestamibi showed H 89 no significant difference in the mitochondrial accumulation between the two tracers. Biodistribution studies in the presence of cyclosporin A revealed an increase

in kidneys and liver uptake of Tc-99m-TMEOP, suggesting the involvement of multidrug resistance transporters in determining its pharmacokinetic profile.

Conclusions: The heart uptake mechanism of Tc-99m-TMEOP is similar to that of the other reported monocationic Tc-99m cardiac agents and is associated with its accumulation in the mitochondria. Cyclosporin A studies indicate that the fast liver and kidney clearance kinetics is mediated by P-glycoprotein (Pgp), supporting the potential interest of this radiotracer Z VAD FMK for imaging Pgp function associated with multidrug-resistant tumours. (C) 2012 Elsevier Inc. All rights reserved.”
“Enoyl-acyl carrier protein (ACP) reductases are critical for bacterial type II fatty acid biosynthesis and thus are attractive

targets for developing novel antibiotics. We determined the crystal structure of enoyl ACP reductase (FabK) from Streptococcus pneumoniae at 1.7 angstrom resolution. There was one dimer per asymmetric unit. Each subunit formed a triose phosphate isomerase (TIM) barrel structure, and flavin mononucleotide (FMN) was bound as a cofactor in the active site. The overall structure was similar to the enoyl-ACP reductase (ER) of fungal fatty acid synthase and to 2-nitropropane dioxygenase (2-ND) from Pseudomonas aeruginosa, although there were some differences among these structures. We determined the crystal structure of FabK in complex with a phenylimidazole derivative inhibitor to envision the binding site interactions. The crystal structure reveals that the inhibitor binds to a hydrophobic pocket in the active site of FabK, and this is accompanied by induced-fit movements of two loop regions.

To obtain the rate of global gray matter volume decline, we calcu

To obtain the rate of global gray matter volume decline, we calculated global gray matter volume and

intracranial volume at baseline and at follow-up using a fully automated method.

The annual percentage change in the gray matter ratio (GMR, APC(GMR)), Selleck Gilteritinib in which GMR represents the percentage of gray matter volume in the intracranial volume, showed a significant positive correlation with the degree of deep WMHs and periventricular WMHs at baseline, after adjusting for age, gender, present history of hypertension, and diabetes mellitus.

Our results suggest that degree of WMHs at baseline predicts the rate of gray matter volume decline 6 years later and that simple visual scaling of WMHs could contribute to predicting the rate of global gray matter volume decline.”
“Objective: The Valsalva graft is a specifically designed Dacron graft that, on implantation and pressurization, generates pseudosinuses of Valsalva. We reviewed a multicenter experience of the reimplantation procedure with the Valsalva graft in patients with aneurysms involving the aortic root.

Methods: A total of 278 patients underwent selleck inhibitor valve-sparing aortic root replacement using the Valsalva graft at 4 different

Italian cardiac surgery centers and were studied by clinical assessment and echocardiography. Of the 278 patients, 220 were men (79%), with a mean age of 56 +/- 15 years. Of the patients, 42 (15%) had

Marfan check details syndrome, 31 (11%) had a bicuspid aortic valve, 13 (5%) had acute aortic dissection, and 136 (49%) had grade 3 or 4+aortic insufficiency. Concomitant cardiac procedures were performed in 78 patients (28%). Additional aortic leaflet repair was necessary in 25 patients (9%). The mean crossclamp time was 120 +/- 27 minutes.

Results: There were 5 (1.8%) operative and 5 (1.8%) late deaths. The mean follow-up was 52 +/- 28 months (range, 2-112 months) and was 100% complete. The cumulative actuarial survival was 95.2% (268 patients). A total of 32 patients (11%) had grade 3 to 4+aortic insufficiency, and 17 of these required late aortic valve replacement (range, 3-78 months). At 10 years of follow-up, the freedom from aortic valve reoperation rate was 91%, and the rate of freedom from residual aortic insufficiency not needing reoperation was 88%.

Conclusions: The reimplantation type of valve-sparing procedure can be facilitated by the use of the Valsalva graft and can be performed with satisfactory perioperative and midterm results. How an optimal root reconstruction will affect the second decade of follow-up has yet to be determined. (J Thorac Cardiovasc Surg 2010;140:S23-7)”
“Protoplasmic astrocytomas are a poorly recognized and uncommon subtype of astrocytoma.

Analysis of SIV Gag-specific responses of gamma interferon, tumor

Analysis of SIV Gag-specific responses of gamma interferon, tumor necrosis factor alpha, interleukin-2, macrophage inflammatory protein 1 beta, and CD107a revealed that the polyfunctionality of Gag-specific CD4(+) T cells, as defined by the multiplicity of these responses, was markedly elevated in the acute phase in NAb-immunized animals. In the chronic phase, despite the absence of detectable NAbs, virus control was maintained, accompanied by polyfunctional Gag-specific T-cell responses. These results implicate virus-specific polyfunctional CD4(+) T-cell responses in this NAb-triggered virus

control, suggesting possible synergism between NAbs and T cells for control of HIV/SIV replication.”
“The nucleocapsid protein (N) of vesicular PF-573228 chemical structure stomatitis virus and other rhabdoviruses plays a central role in the assembly and template functions of the viral N-RNA complex. The crystal structure of the viral N-RNA complex suggests that the central region of the N protein interacts with the Quizartinib purchase viral RNA. Sequence alignment of rhabdovirus N proteins revealed several highly conserved regions, one of which spanned residues 282 to 291 (GLSSKSPYSS) in the central region of the molecule. Alanine-scanning mutagenesis of this region suggested that replacement of the tyrosine residue at position 289 (Y289) with alanine resulted in an N-RNA template that is nonfunctional

in viral genome replication and transcription. To establish the molecular basis of this defect, our further studies revealed that the Y289A mutant maintained its interaction

Milciclib datasheet with other N protein molecules but that its interactions with the P protein or with the viral RNA were defective. Replacement of Y289 with other aromatic, polar, or large amino acids indicated that the hydrophobic and aromatic nature of this position in the N protein is functionally important and that a larger aromatic residue is less favorable. Interestingly, we have observed that several single-amino-acid substitutions in this highly conserved region of the molecule rendered the nucleocapsid template nonfunctional in transcription without adversely affecting the replication functions. These results suggest that the structure of the N protein and the resulting N-RNA complex, in part, regulate the viral template functions in transcription and replication.”
“The cell-to-cell transport of plant viruses depends on one or more virus-encoded movement proteins (MPs). Some MPs are integral membrane proteins that interact with the membrane of the endoplasmic reticulum, but a detailed understanding of the interaction between MPs and biological membranes has been lacking. The cell-to-cell movement of the Prunus necrotic ringspot virus (PNRSV) is facilitated by a single MP of the 30K superfamily.

CONCLUSION: After an average of more than 15 years of follow-up,

CONCLUSION: After an average of more than 15 years of follow-up, epilepsy surgery patients had fewer seizures, used less antiepileptic medication, and had better HRQoL in several dimensions of the Quality of Life in Epilepsy Inventory 89 instrument than matched medically treated controls with refractory epilepsy, although possibly at a slight disadvantage in the language dimension among those with 7 years of followup or less.”
“OBJECTIVE: Radiosurgical ablation of the mesial temporal lobe structures can be used in the treatment of intractable temporal lobe epilepsy associated with mesial temporal

sclerosis. In this study, we analyzed the magnetic Bindarit order resonance imaging (MRI) and spectroscopic changes that follow the treatment and report the clinical sequelae of the procedure.

METHODS: Eight patients (five men and three women; age, 38 +/- 15 yr [mean standard deviation]) with mesial temporal sclerosis were treated with radiosurgical amygdalohippocampectomy (25 Gy to the 50% isodose region with a mean target volume of 6.2 +/- 0.7 cm(3)). MRI and magnetic resonance spectroscopy were performed sequentially during a 24-month period after treatment.

RESULTS: Patients were followed up clinically for 24 to 53 months. MRI scans MRT67307 revealed changes of marked temporal lobe swelling, with

often markedly elevated apparent diffusion coefficients in keeping with vasogenic edema that became apparent 6 to 12 months after stereotactic radiosurgery. Spectroscopy of the target area revealed a progressive loss of N-acetylaspartate (the late evolution of lactate) and a peak in the choline-to-creatine ratio that seemed to coincide with the peak of the vasogenic edema in the temporal lobe surrounding the target area. Clinically, all patients showed some reduction in seizure frequency, although in two patients, this reduction was modest. The MRI changes in those patients were also modest, and three patients ultimately became free of seizures. However, there was a latency of 18 to 24 months before improvements

in seizure control occurred, and during this period, seizures worsened or changed in four patients. Two patients also developed symptoms of increased intracranial pressure LY3023414 manufacturer with mild dysphasia, which responded to administration of corticosteroid medication. However, no long-term clinical verbal memory decline was identified in any patient.

CONCLUSION: There are marked changes in MRI scans and magnetic resonance spectroscopic findings after patients undergo radiosurgery for temporal lobe epilepsy. Our initial findings suggest that some patients may have a period of distressing symptoms that accompany changes that are visualized on the MRI scans.”
“OBJECTIVE: Tremor and rigidity have been efficiently controlled by electrical stimulation of contralateral prelemniscal radiations (Raprl) in patients with unilateral Parkinson’s disease.

Standard medium (SM) amendments to sardine and tuna by-product-ba

Standard medium (SM) amendments to sardine and tuna by-product-based media stimulated the growth of S. xylosus and the highest A(600) values WZB117 mw were obtained with 75% SM. Lipase activity, however, remained below 4 U ml(-1) for both sardine and tuna by-product-based media.

Fish by-products could be used for the production of highly valuable enzymes.

The use of fish by-products in producing S. xylosus-growth media can reduce environmental problems associated with waste disposal

and, simultaneously, lower the cost of biomass and enzyme production.”
“The significance and functional roles of glycogen shunt activity in the brain are largely unknown. It represents the fraction of metabolized glucose that passes through glycogen molecules prior to entering the glycolytic pathway. The present study was aimed at elucidating this pathway in cultured astrocytes from mouse exposed to agents such as a high [K(+)], D-aspartate and norepinephrine (NE) known to affect energy metabolism in response to neurotransmission. Glycogen shunt activity was assessed employing [1,6-(13)C]glucose, Epigenetics and the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) to block glycogen degradation. The label intensity in lactate, reflecting glycolytic activity, was determined by mass spectrometry. In the presence of NE a substantial glycogen shunt activity was observed, accounting for almost 40% of overall glucose metabolism. Moreover, when no metabolic

stimulant was applied, a compensatory increase in glycolytic activity Mephenoxalone was seen when the shunt was inhibited by DAB. Actually the labeling in lactate exceeded that obtained when glycolysis and glycogen shunt both were operational, i.e. supercompensation. A similar phenomenon was seen when astrocytes

were exposed to D-aspartate. In addition to glycolysis, tricarboxylic acid (TCA) cycle activity was monitored, analyzing labeling by mass spectrometry in glutamate which equilibrates with alpha-ketoglutarate. Both an elevated [K] and D-aspartate induced an increased TCA cycle activity, which was altered when glycogen degradation was inhibited. Thus, the present study provides evidence that manipulation of glycogen metabolism affects both glycolysis and TCA cycle metabolism. Altogether, the results reveal a highly complex interaction between glycogenolysis and glycolysis, with the glycogen shunt playing a significant role in astrocytic energy metabolism. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.”
“To evaluate the effect of four different baking enzymes on the inhibitory activity of five bacteriocin-like inhibitory substances (BLIS) produced by lactic acid bacteria (LAB) isolated from Lithuanian sourdoughs.

The overlay assay and the Bioscreen methods revealed that the five BLIS exhibited an inhibitory effect against spore germination and vegetative outgrowth of Bacillus subtilis, the predominant species causing ropiness in bread.

Our findings give deeper insights into the mechanisms of intramem

Our findings give deeper insights into the mechanisms of intramembrane-cleaving proteases

and the impact on viral infections.”
“We used magnetic resonance imaging to examine the effect of ethyl-eicosapentaenoic acid (E-EPA) on hippocampal T-2 relaxation time in first episode psychosis patients at baseline and after 12 weeks of follow-up There was an increase in T-2 in the placebo group but not in the E-EPA group, suggesting a neuroprotective effect of E-EPA treatment In addition, the smaller the increase in T-2, the greater the improvement in negative symptoms. (C) 2010 Elsevier Ireland Ltd All rights reserved.”
“Recent developments in the technology to breed and house laboratory rodents for medical research has produced individually Cisplatin concentration ventilated cage (IVC) systems. These IVC systems produce a cage environment significantly different to conventional cages. As it is not known in detail whether housing mice in IVCs impacts on their baseline and drug-induced behaviours compared to mice of conventional filter-top cages a comprehensive multi-tiered phenotyping strategy was used to test the behavioural consequences of IVC housing in male and female C57BL/6JArc mice. IVC had anxiety-like effects in the elevated plus maze, which were more pronounced H 89 purchase in female mice whereas cognition and locomotion of all test mice

were not modified by IVC housing. Mice raised in IVC cage systems were socially more active than mice of filter-top systems. Furthermore, males raised in IVC exhibited an increased

sensitivity to the locomotor-stimulating effects of acute MK-801 treatment compared to males in conventional cages. In summary, this is the first study revealing the WH-4-023 ic50 longer-term effects of IVC housing on social behaviours and the locomotor response to an acute MK-801 challenge. In conclusion, researchers upgrading their holding facilities to IVC housing may encounter a shift in experimental outcomes (e.g. post pharmacological challenges) and the behavioural phenotype of test mice. Furthermore, differences between the housing conditions of breeding facilities and test facilities must carefully be considered. Finally, researchers should clarify in detail the type of housing test animals have been exposed to when publishing experimental animal research data. (C) 2013 IBRO. Published by Elsevier Ltd. All rights reserved.”
“A pediatric human immunodeficiency virus type 1 (HIV-1) vaccine would be desirable to protect infants against HIV-1 transmission from breast-feeding. Such a vaccine would need to induce protective immunity at mucosal surfaces in neonates as soon as possible after birth. Recombinant adenovirus (rAd) vectors have been shown to elicit potent systemic and mucosal virus-specific immune responses in adult nonhuman primates and humans, but these vectors have not previously been comprehensively studied in infants.

However, even though the ends of orthopoxviruses are more genetic

However, even though the ends of orthopoxviruses are more genetically plastic than the cores, there are still many telomeric genes that are conserved as intact open reading frames in the 11 genomes that we, and 4 genomes that others, have sequenced.

Most of these genes likely modulate inflammation. Our sequencing also detected an evolving pattern of mutation, with some genes being highly fragmented by randomly assorting mutations (e. g., M1L), while other genes are intact in most viruses but have been disrupted in individual strains (e. g., I4L in strain DPP17). Over 85% of insertion and deletion mutations are associated with repeats, and a rare new isolate selleck products bearing a large deletion in the right telomere was identified. All of these strains cluster in dendrograms consistent with Selleckchem Verubecestat their origin but which also surprisingly incorporate horsepox virus. However, these viruses also exhibit a “”patchy”" pattern of polymorphic sites characteristic of recombinants. There is more genetic diversity detected within a vial of Dryvax than between variola virus major and minor strains, and our study highlights how propagation methods affect the genetics of orthopoxvirus populations.”

studied brain activity during retention and retrieval phases of two visual short-term memory (VSTM) experiments. Experiment 1 used a. balanced memory array, with one color stimulus in each hemifield, followed by a retention interval and a central probe, at the fixation point that designated the target stimulus in memory about which to make a determination of orientation. Retrieval of information from VSTM was associated with an event-related lateralization (ERL) with a contralateral negativity relative to

the visual field from which the probed stimulus was originally encoded, suggesting a lateralized organization of VSTM. The scalp distribution of Taselisib the retrieval ERL was more anterior than what is usually associated with simple maintenance activity, which is consistent with the involvement of different brain structures for these distinct visual memory mechanisms. Experiment 2 was like Experiment 1, but used an unbalanced memory array consisting of one lateral color stimulus in a hemifield and one color stimulus on the vertical mid-line. This design enabled us to separate lateralized activity related to target retrieval from distractor processing. Target retrieval was found to generate a negative-going ERL at electrode sites found in Experiment 1, and suggested representations were retrieved from anterior cortical structures. Distractor processing elicited a positive-going ERL at posterior electrodes sites, which could be indicative of a return to baseline of retention activity for the discarded memory of the now-irrelevant stimulus, or an active inhibition mechanism mediating distractor suppression. (C) 2012 Elsevier Ltd. All rights reserved.