scholarly journals Position specificity of adaptation-related face aftereffects

2011 ◽  
Vol 366 (1564) ◽  
pp. 586-595 ◽  
Author(s):  
Márta Zimmer ◽  
Gyula Kovács
Keyword(s):  
Prolonged Exposure ◽  
Saccadic Eye Movements ◽  
Object Representations ◽  
Human Face ◽  
Visual Stability ◽  
Multiple Components ◽  
Processing Stream ◽  
Position Specificity ◽  
Shape Selective

It has been shown that prolonged exposure to a human face leads to shape-selective visual aftereffects. It seems that these face-specific aftereffects (FAEs) have multiple components, related to the adaptation of earlier and higher level processing of visual stimuli. The largest magnitude of FAE, using long-term adaptation periods, is usually observed at the retinotopic position of the preceding adaptor stimulus. However, FAE is also detected, to a smaller degree, at other retinal positions in a spatially invariant way and this component depends less on the adaptation duration. Several lines of evidences suggest that while the position-specific FAE involves lower level areas of the ventral processing stream, the position-invariant FAE depends on the activation of higher level face-processing areas and the fusiform gyrus in particular. In the present paper, we summarize the available behavioural, electrophysiological and neuroimaging results regarding the spatial selectivity of FAE and discuss their implications for the visual stability of object representations across saccadic eye movements.

scholarly journals Impact of Prolonged Exposure of Eleven Years to Hot Seawater on the Degradation of a Thermoset Composite

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2154
Author(s):  
Amir Hussain Idrisi ◽  
Abdel-Hamid I. Mourad ◽  
Muhammad M. Sherif
Keyword(s):  
Exposure Time ◽  
Prolonged Exposure ◽  
Mechanical Performance ◽  
Matrix Cracking ◽  
Pull Out ◽  
Strength Based ◽  
Different Temperatures ◽  
River Line ◽  
Composite Samples

This paper presents a long-term experimental investigation of E-glass/epoxy composites’ durability exposed to seawater at different temperatures. The thermoset composite samples were exposed to 23 °C, 45 °C and 65 °C seawater for a prolonged exposure time of 11 years. The mechanical performance as a function of exposure time was evaluated and a strength-based technique was used to assess the durability of the composites. The experimental results revealed that the tensile strength of E-glass/epoxy composite was reduced by 8.2%, 29.7%, and 54.4% after immersion in seawater for 11 years at 23 °C, 45 °C, and 65 °C, respectively. The prolonged immersion in seawater resulted in the plasticization and swelling in the composite. This accelerated the rate of debonding between the fibers and matrix. The failure analysis was conducted to investigate the failure mode of the samples. SEM micrographs illustrated a correlation between the fiber/matrix debonding, potholing, fiber pull-out, river line marks and matrix cracking with deterioration in the tensile characteristics of the thermoset composite.

scholarly journals Onset and Resolution of Key Adverse Events in Valbenazine-Treated Patients with Tardive Dyskinesia: Pooled Analyses from Two Long-Term Clinical Trials

CNS Spectrums ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 151-151
Author(s):  
Stephen R. Marder ◽  
Jean-Pierre Lindenmayer ◽  
Chirag Shah ◽  
Tara Carmack ◽  
Angel S. Angelov ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Adverse Events ◽  
Tardive Dyskinesia ◽  
Suicidal Behavior ◽  
Prolonged Exposure ◽  
First Occurrence ◽  
Balance Disorder ◽  
Clinical Interest ◽  
Post Hoc

AbstractObjectiveTardive dyskinesia (TD) is a persistent and potentially disabling movement disorder associated with prolonged exposure to antipsychotics and other dopamine receptor blocking agents. Long-term safety of the approved TD medication, valbenazine, was demonstrated in 2 clinical trials (KINECT 3 [NCT02274558], KINECT 4 [NCT02405091]). Data from these trials were analyzed post hoc to evaluate the onset and resolution of adverse events (AEs).MethodsParticipants in KINECT 3 and KINECT 4 received up to 48 weeks of once-daily valbenazine (40 or 80 mg). Data from these studies were pooled and analyzed to assess the incidence, time to first occurrence, and resolution for the following AEs of potential clinical interest: akathisia, balance disorder, dizziness, parkinsonism, somnolence/sedation, suicidal behavior/ideation, and tremor.ResultsIn the pooled population (N=314), all AEs of potential clinical interest occurred in <10% of participants, with somnolence (9.6%), suicidal behavior/ideation (6.4%), and dizziness (5.7%) being the most common AEs. Mean time to first occurrence ranged from 36 days (akathisia [n=9]) to 224 days (parkinsonism [n=2]). By end of study (or last study visit), resolution of AEs was as follows: 100% (suicidal ideation/behavior, parkinsonism); >85% (somnolence/sedation, dizziness); >70% (akathisia, balance disorder, tremor).ConclusionsIn long-term clinical trials, the incidence of AEs of potential clinical interest was low (<10%) and most were resolved by end of treatment (>70–100%). All patients taking valbenazine should be routinely monitored for AEs, particularly those that may exacerbate the motor symptoms associated with TD.FundingNeurocrine Biosciences, Inc.

scholarly journals The phosphoproteome of rice leaves responds to water and nitrogen supply

2021 ◽  
Author(s):  
Sara Hamzelou ◽  
Vanessa J. Melino ◽  
Darren C. Plett ◽  
Karthik Shantharam Kamath ◽  
Arkadiusz Nawrocki ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Water Channel ◽  
Nitrogen Supply ◽  
Nitrogen Fertilizers ◽  
Label Free ◽  
Limited Information ◽  
Irrigated Rice ◽  
Post Translational Modifications ◽  
Growth Adaptation

The scarcity of freshwater is an increasing concern in flood-irrigated rice, whilst excessive use of nitrogen fertilizers is both costly and contributes to environmental pollution. To co-ordinate growth adaptation under prolonged exposure to limited water or excess nitrogen supply, plants have processes for signalling and regulation of metabolic processes. There is limited information on the involvement of one of the most important post-translational modifications (PTMs), protein phosphorylation, on plant adaptation to long-term changes in resource supply. Oryza sativa cv. Nipponbare was grown under two regimes of nitrogen from the time of germination to final harvest. Twenty-five days after germination, water was withheld from half the pots in each nitrogen treatment and low water supply continued for an additional 26 days, while the remaining pots were well watered. Leaves from all four groups of plants were harvested after 51 days in order to test whether phosphorylation of leaf proteins responded to prior abiotic events. The dominant impact of these resources is exerted in leaves, where PTMs have been predicted to occur. Proteins were extracted and phosphopeptides were analysed by nanoLC-MS/MS analysis, coupled with label-free quantitation. Water and nitrogen regimes triggered extensive changes in phosphorylation of proteins involved in membrane transport, such as the aquaporin OsPIP2-6, a water channel protein. Our study reveals phosphorylation of several peptides belonging to proteins involved in RNA-processing and carbohydrate metabolism, suggesting that phosphorylation events regulate the signalling cascades that are required to optimize plant response to resource supply.

scholarly journals Cheaters shape the evolution of phenotypic heterogeneity in Bacillus subtilis biofilms

2018 ◽  
Author(s):  
Marivic Martin ◽  
Anna Dragoš ◽  
Simon B. Otto ◽  
Daniel Schäfer ◽  
Susanne Brix ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Prolonged Exposure ◽  
Adaptive Strategy ◽  
Phenotypic Heterogeneity ◽  
Structural Proteins ◽  
Cell Level ◽  
General Adaptation ◽  
Matrix Production ◽  
Matrix Components

ABSTRACTBiofilms are closely packed cells held and shielded by extracellular matrix composed of structural proteins and exopolysaccharides (EPS). As matrix components are costly to produce and shared within the population, EPS-deficient cells can act as cheaters by gaining benefits from the cooperative nature of EPS producers. Remarkably, genetically programmed EPS producers can also exhibit phenotypic heterogeneity at single cell level. Previous studies have shown that spatial structure of biofilms limits the spread of cheaters, but the long-term influence of cheating on biofilm evolution is not well understood. Here, we examine the influence of EPS non-producers on evolution of matrix production within the populations of EPS producers in a model biofilm-forming bacterium, Bacillus subtilis. We discovered that general adaptation to biofilm lifestyle leads to an increase in phenotypical heterogeneity of eps expression. Apparently, prolonged exposure to EPS-deficient cheaters, may result in different adaptive strategy, where eps expression increases uniformly within the population. We propose a molecular mechanism behind such adaptive strategy and demonstrate how it can benefit the EPS-producers in the presence of cheaters. This study provides additional insights on how biofilms adapt and respond to stress caused by exploitation in long-term scenario.

Delayed arteriolar relaxation after prolonged agonist exposure: functional remodeling involving tyrosine phosphorylation

2003 ◽  
Vol 285 (2) ◽  
pp. H849-H856 ◽  
Author(s):  
Michael A. Hill ◽  
Simon J. Potocnik ◽  
Luis A. Martinez-Lemus ◽  
Gerald A. Meininger
Keyword(s):  
Tyrosine Phosphorylation ◽  
Prolonged Exposure ◽  
Time Dependent ◽  
Physiological Salt Solution ◽  
Microtubule Network ◽  
Biochemical Alterations ◽  
Dependent Behavior ◽  
Functional Remodeling ◽  
Short And Long Term

Although arteriolar contraction is dependent on Ca2+-induced myosin phosphorylation, other mechanisms including Ca2+ sensitization and time-dependent phenomena such as cytoskeletal and cellular reorganization may contribute to contractile events. We hypothesized that if arteriolar smooth muscle exhibits time-dependent behavior this may be manifested in differences in relaxation after short- and long-term exposure to contractile agonists. Studies were conducted in isolated arterioles pressurized to 70 mmHg. In initial experiments ( n = 10), rate of relaxation was measured after acute (5 min) or prolonged (4 h) exposure to 5 μM norepinephrine (NE). Prolonged exposure to NE resulted in significantly ( P < 0.05) increased time for relaxation in physiological salt solution. Rapid relaxation of vessels exposed to NE for 4 h was observed after superfusion with 0 mM Ca2+ buffer, indicating that the alteration in relaxation was reversible and Ca2+ dependent. A similarly impaired dilation was not observed with 4-h exposure to KCl (75 mM). To determine mechanisms contributing to the effects of prolonged NE exposure, studies were performed in the presence of the microtubule depolymerizing agent demecolcine (10 μM) or a series of tyrosine phosphorylation inhibitors. Although demecolcine caused significant vasoconstriction ( P < 0.05) and potentiated NE vasoconstriction, it did not prevent the effect of long-term NE exposure on relaxation. Genistein, although having no effect on acute NE-induced contraction, concentration-dependently inhibited prolonged NE constriction. Similarly, Src (PP1) and p42/44 MAP kinase (PD-98059) inhibitors prevented maintenance of long-term NE contraction. The data indicate that prolonged exposure to NE induces biochemical alterations that impair relaxation after removal of the agonist. The contractile effects are Ca2+ dependent and involve tyrosine phosphorylation but do not appear to involve the polymerization state of the microtubule network.

scholarly journals Prolonged exposure to low oxygen improves hypoxia tolerance in a freshwater fish

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Kayla L Gilmore ◽  
Zoe A Doubleday ◽  
Bronwyn M Gillanders
Keyword(s):  
Freshwater Fish ◽  
Prolonged Exposure ◽  
Hypoxia Tolerance ◽  
Low Oxygen ◽  
Oxygen Conditions

Lay summary It is poorly understood whether fish can acclimate to prolonged low-oxygen conditions (or hypoxia). Our study shows that prior long-term exposure to low-oxygen conditions improves tolerance to low-oxygen in a freshwater fish. The results of our study aid our understanding of long-term responses of freshwater fish to low-oxygen to hypoxic events.

Long-term regulation of hexose uptake by isoproterenol in cultured 3T3 adipocytes

1985 ◽  
Vol 248 (6) ◽  
pp. E706-E711 ◽  
Author(s):  
J. P. van Putten ◽  
H. M. Krans
Keyword(s):  
Protein Synthesis ◽  
Prolonged Exposure ◽  
Term Effect ◽  
Long Term Effects ◽  
Fat Cell ◽  
Short Term ◽  
Long Term Effect ◽  
Short Term Exposure ◽  
Hexose Uptake

Catecholamines are known to have short-term regulatory effects on fat cell hexose uptake. We examined the long-term effects of catecholamines on the insulin-sensitive 2-deoxyglucose (dGlc) uptake in cultured 3T3-L1 adipocytes. Prolonged exposure (48 h) to isoproterenol (beta-adrenergic agonist) stimulated the basal dGlc uptake up to 90%. The effect was specific, time, concentration, and protein synthesis dependent and reversible. The effect of insulin was unaltered and superimposed on the increase in basal dGlc uptake. The long-term effect of isoproterenol was mimicked by epinephrine, dibutyryl cAMP (DBcAMP), and 1-methyl-3-isobutylxanthine (IBMX). By contrast, short-term exposure to isoproterenol (and epinephrine) induced a protein synthesis-independent increase in basal dGlc uptake (30%) not accompanied by an increase in insulin responsiveness. Moreover, on short-term basis, DBcAMP and IBMX suppressed both the basal and insulin-stimulated uptake up to 50%. Determination of the intracellular nonphosphorylated dGlc during the uptake and of the hexokinase activity revealed that the long-term effect of isoproterenol was most likely due to alterations low in dGlc transport. In conclusion, long-term regulators of hexose uptake are in cultured 3T3-L1 adipocytes, isoproterenol, and other cAMP stimulators. The long-term effect is independent from the short-term regulatory effect of the agents and from the effect of insulin.

Temporal effects of cytokines on neonatal cardiac myocyte Ca2+ transients and adenylate cyclase activity

1997 ◽  
Vol 272 (4) ◽  
pp. H1937-H1944 ◽  
Author(s):  
R. J. Bick ◽  
J. P. Liao ◽  
T. W. King ◽  
A. LeMaistre ◽  
J. B. McMillin ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Cardiac Myocyte ◽  
Prolonged Exposure ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Short Exposure ◽  
Adenylate Cyclase System ◽  
Long Term Treatment

This study investigates the hypothesis that inflammatory cytokines, interleukin (IL)-1alpha IL-1beta, and tumor necrosis factor (TNF), influence cardiac function by affecting calcium homeostasis and that this effect is mediated by the beta-adrenergic-adenylate cyclase system. After 4 days in culture, neonatal rat ventricular myocytes were treated with cytokines (10 ng/ml) for short (2 h) or longer (18 h) times. Myocyte calcium, contractility, and adenylate cyclase were measured under each condition. Anticipated stepwise increases in adenylate cyclase and intracellular calcium were found in controls (non-cytokine-treated) with 10(-7) M isoproterenol, 10(-7) M isoproterenol + 0.1 mM guanosine triphosphate, and 10(-9) M forskolin. Cells in the presence of cytokine for 2 h show increased basal calcium levels but no changes in adenylate cyclase activities, and isoproterenol fails to elevate adenylate cyclase levels or affect contractile shortening. After long-term treatment with IL-1beta or TNF, but not IL-1alpha, the significantly elevated levels of basal systolic calcium remain, and isoproterenol increases adenylate cyclase activity, unlike after short exposure. Forskolin maximally activates adenylate cyclase following both short- and long-term incubation, but the stepwise increase in activity is blunted following prolonged exposure. Thus short-term cytokine treatment blocks the adrenergic receptor-mediated increases in adenosine 3',5'-cyclic monophosphate, dissociating adenylate cyclase activation from cytokine-mediated increases in cell calcium, whereas longer treatment apparently produces direct affects on adenylate cyclase. Time-dependent differences in contractile response were found with IL-1alpha at 2 h and TNF at 18 h, implying that myofibrillar responsiveness to increased cytoplasmic calcium is dependent on both cytokine species and exposure time.

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