#3071 Acute escitalopram administration increases premature responding as a function of reward magnitude in healthy male volunteers

2021 ◽  
Vol 92 (8) ◽  
pp. A8-A8
Author(s):  
N Skandali ◽  
BJ Sahakian ◽  
TWR Robbins ◽  
V Voon
Keyword(s):  
Reaction Time ◽  
Response Inhibition ◽  
Motor Response ◽  
Reaction Time Task ◽  
Serial Reaction Time Task ◽  
Stop Signal ◽  
Reward Processing ◽  
Test Block ◽  
Healthy Male ◽  
Serial Reaction

ObjectivesImpulsivity is a multifaceted construct that involves a tendency to act prematurely with little foresight, reflection or control. Waiting impulsivity is one aspect of action impulsivity and is commonly studied in animals using tasks such as the 5-choice serial reaction time task (5CSRTT).1 It is neurochemically distinct from motor response inhibition defined as the ability to restrain or cancel a pre-potent motor response and measured with no-go and stop-signal tasks respectively.1 Serotonin modulates waiting impulsivity as decreased serotonergic transmission promotes premature responding in the rodent 5CSRT and the human analogue 4CSRT task.2 Potential mechanisms contributing to waiting impulsivity include proactive or tonic inhibition, motivational processes and sensitivity to feedback and delay.3 Higher waiting impulsivity in response to high reward cues was previously associated with greater subthalamic nucleus connectivity with orbitofrontal cortex and greater subgenual cingulate connectivity with anterior insula.4MethodsWe administered a clinically relevant dose of escitalopram (20mg) in healthy subjects in a double-blind, placebo-controlled, parallel-groups design study and assessed its effect on waiting impulsivity using the well-validated 4CSRT task. Compared to previous studies,2 4 we added another test block with increased potential gain to assess the interaction between premature responding and reward processing. We recruited sixty-six healthy participants who completed an extensive neuropsychological test battery assessing probabilistic reversal learning, set-shifting, response inhibition, emotional processing and waiting impulsivity. Sixty participants (N=60, 26 females, 34 males) completed the 4CSRT task with N=30 in the escitalopram and N=30 in the placebo group, due to technical errors and experienced side-effects for the remaining six participants. The results of the other cognitive tasks are reported separately.5ResultsEscitalopram increased premature responding in the high incentive condition of the 4CSRT task, p=.028, t= 2.275, this effect being driven by male participants, p=.019, t=2.532 (for females, p>.05). We further show that escitalopram increased premature responses after a premature response in the same block again in male participants only, p=.034, Mann-Whitney U= 61.500. We found no correlation between premature responding in the 4CSRT task, in any test block, and the Stop-signal reaction time, the primary measure of the stop-signal task completed by the same participants (reported in [5]).ConclusionsWe show that acute escitalopram increased premature responding in healthy male participants only in high incentive conditions potentially mediated potentially through an effect on increased incentive salience. We also show that acute escitalopram increased perseverative responding thus producing a maladaptive response strategy. We show no correlation between SSRT and premature responding in the same participants consistent with these two forms of impulsivity being neurochemically and anatomically distinct. We interpret our findings in the context of acute escitalopram decreasing serotonergic transmission in some brain areas through inhibitory actions on terminal 5-HT release mediated by auto-receptors on raphe 5-HT neurons analogous to the presumed transient reduction in 5-HT activity caused by ATD.5Our findings provide further insights in the relationship of premature responding and reward processing and our understanding of pathological impulse control behaviours.References Eagle DM, Bari A, Robbins TW. The neuropsychopharmacology of action inhibition: cross-species translation of the stop-signal and go/no-go tasks. Psychopharmacology 2008;199(3):439456. Worbe Y, Savulich G, Voon V, Fernandez-Egea E, Robbins TW. Serotonin depletion induces waiting impulsivityon the human four-choice serial reaction time task: cross-species translational significance. Neuropsychopharmacology 2014;39(6):15191526. Voon V. Models of impulsivity with a focus on waiting impulsivity: translational potential for neuropsychiatric disorders. Current Addiction Reports 2014;1(4):281288. Mechelmans DJ, Strelchuk D, Doamayor N, Banca P, Robbins TW, Baek K, et al. Reward sensitivity and waiting impulsivity: shift towards reward valuation away from action control. International Journal of Neuropsychopharmacology 2017;20(12):971978. Skandali N, Rowe JB, Voon V, Deakin JB, Cardinal RN, Cormack F, et al. Dissociable effects of acute SSRI (escitalopram) on executive, learning and emotional functions in healthy humans. Neuropsychopharmacology 2018;43(13):26452651.

scholarly journals Synergistic Excitation Mechanism of CaO-SiO2-Al2O3-SO3 Quaternary Active Cementitious System

2021 ◽  
Vol 8 ◽  
Author(s):  
Fusheng Niu ◽  
Yukun An ◽  
Jinxia Zhang ◽  
Wen Chen ◽  
Shengtao He
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Test Block ◽  
Hydration Reaction ◽  
Alkaline Environment ◽  
Granulated Blast Furnace Slag ◽  
Cementitious System ◽  
Furnace Slag

In this study, the influence of steel slag (SS) content on the strength of the cementitious materials was investigated. The quaternary active cementitious material (CaO-SiO2-Al2O3-SO3) was prepared using various proportions of steel slag (SS), granulated blast furnace slag (BFS), and desulfurized gypsum (DG). The mechanism of synergistic excitation hydration of the cementitious materials was examined using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The strength of the mortar test block was initially increased and decreased later with the increase of the SS content. Mortar test block with 20% steel slag, 65% granulated blast furnace slag, and 15% desulfurized gypsum with 0.35 water-binder ratio showed the highest compressive strength of 57.3 MPa on 28 days. The free calcium oxide (f-CaO) in the SS reacted with water and produced calcium hydroxide (Ca(OH)2) which created an alkaline environment. Under the alkaline environment, the alkali-activated reaction occurred with BFS. In the early stage of hydration reaction, calcium silicate hydrate (C-S-H) gel and fibrous hydration product ettringite (AFt) crystals were formed, which provided early strength to the cementitious materials. As the hydration reaction progressed, the interlocked growth of C-S-H gel and AFt crystals continued and promoted the increase of the strength of the cementitious system.

scholarly journals Research on the Difference of Physical Parameters of Concrete in Saline-alkali Environment

2020 ◽  
Vol 143 ◽  
pp. 01014
Author(s):  
Yumao Qi ◽  
Junge Huang ◽  
Yu Liu ◽  
Jian Pei
Keyword(s):  
Reinforced Concrete ◽  
Sodium Sulfate ◽  
Rock Specimen ◽  
Test Block ◽  
Control Group ◽  
Physical Parameters ◽  
Significant Difference ◽  
Specimen Test ◽  
Water Test ◽  
The Difference

In order to better study the corrosion of concrete in saline-alkali area, the model tests of concrete and reinforced concrete with different ions and different ion concentrations were constructed. Taking the test blocks mixed with water as the control group, the resistance and polarizability of the test block during the maintenance period were measured by rock specimen tester and rock specimen test frame. The one-way variance analysis of the measured values of each test block was carried out by spss software, investigating the difference of electrical parameters of each concrete. The results show that there is significant difference in the resistance between the clear water concrete test block and the 3% sodium sulfate concrete test block at the level of significance ≤ 0.05. For reinforced concrete test blocks, the resistivity difference between water test block and 3% sodium sulfate test block and 6% sodium sulfate test block is not significant, and the resistivity difference between water test block and 15% sodium sulfate test block and 3% sodium chloride test block is significant. No matter concrete or reinforced concrete, the polarizability of test blocks mixed with water and test blocks mixed with each solution is significantly different. Therefore, the polarizability parameters can be used to distinguish whether the concrete is corroded by salt and alkali. It is feasible to use polarizability parameter to detect concrete erosion by salt and alkali.

Daily training with high carbohydrate availability increases exogenous carbohydrate oxidation during endurance cycling

2010 ◽  
Vol 109 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Gregory R. Cox ◽  
Sally A. Clark ◽  
Amanda J. Cox ◽  
Shona L. Halson ◽  
Mark Hargreaves ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Substrate Oxidation ◽  
Carbohydrate Intake ◽  
Whole Body ◽  
Test Block ◽  
Vastus Lateralis Muscle ◽  
Mitochondrial Enzymes ◽  
High Group ◽  
High Carbohydrate ◽  
Daily Training

We determined the effects of varying daily carbohydrate intake by providing or withholding carbohydrate during daily training on endurance performance, whole body rates of substrate oxidation, and selected mitochondrial enzymes. Sixteen endurance-trained cyclists or triathletes were pair matched and randomly allocated to either a high-carbohydrate group (High group; n = 8) or an energy-matched low-carbohydrate group (Low group; n = 8) for 28 days. Immediately before study commencement and during the final 5 days, subjects undertook a 5-day test block in which they completed an exercise trial consisting of a 100 min of steady-state cycling (100SS) followed by a 7-kJ/kg time trial on two occasions separated by 72 h. In a counterbalanced design, subjects consumed either water (water trial) or a 10% glucose solution (glucose trial) throughout the exercise trial. A muscle biopsy was taken from the vastus lateralis muscle on day 1 of the first test block, and rates of substrate oxidation were determined throughout 100SS. Training induced a marked increase in maximal citrate synthase activity after the intervention in the High group (27 vs. 34 μmol·g−1·min−1, P < 0.001). Tracer-derived estimates of exogenous glucose oxidation during 100SS in the glucose trial increased from 54.6 to 63.6 g ( P < 0.01) in the High group with no change in the Low group. Cycling performance improved by ∼6% after training. We conclude that altering total daily carbohydrate intake by providing or withholding carbohydrate during daily training in trained athletes results in differences in selected metabolic adaptations to exercise, including the oxidation of exogenous carbohydrate. However, these metabolic changes do not alter the training-induced magnitude of increase in exercise performance.

Development of Small Diameter and Thin-Walled Tube Docking Girth Joint Ultrasonic Testing Probe and Block

2018 ◽  
Author(s):  
Lu-yun Zhou ◽  
Ming-hai Fu ◽  
Wei-pu Xu
Keyword(s):  
Ultrasonic Testing ◽  
Dead Zone ◽  
Sheet Steel ◽  
Small Diameter ◽  
Steel Tube ◽  
Test Block ◽  
Thin Wall ◽  
Ultrasonic Scattering ◽  
Thin Walled Tube ◽  
Thin Walled

Due to the Small diameter and thin walled tube docking girth joint ultrasonic testing has the problems of: dead zone is often greater than the wall thickness; large curvature of the pipeline causes ultrasonic scattering, greatly reduces the sensitivity; pipe weld root’s is not welded and so on. In this paper, the prepared small-bore and sheet steel tube docking girth joint ultrasonic testing probe has sufficient sensitivity, is less than 2.5mm of initial pulse width, short front (≤ 5mm), high resolution, less clutter, less surface wave components, At the same time, the test block was designed and used for the testing of probe’s related technical indicators, the test block can meet the focus probe’s performance and scanning sensitivity calibration. Combined with the field detection and compared with the radiographic testing, the ultrasonic testing obtain good result. It is suitable for the ultrasonic quantitative testing of the joint ring weld of thin wall pipe.

scholarly journals The Effect of Firing Temperature on Water Absorption and Flexural Strength on The Preparation of Stoneware Ceramic (Coded-BL1P)

2019 ◽  
Vol 20 (1) ◽  
pp. 25 ◽  
Author(s):  
G. Agus Permana Putra Sujana ◽  
Putu Suardana ◽  
Totok Nugroho
Keyword(s):  
Flexural Strength ◽  
Water Absorption ◽  
Firing Temperature ◽  
Test Block ◽  
Casting Method ◽  
Temperature Variations ◽  
Made In

It has been investigated the effect of firing temperature on water absorption and flexural strength in the manufacture of BL1P code stoneware ceramics. Ceramics are made in the form the test block bar with materials from of Borneo Clay Noodle, PRC Feldspar, Kaolin Belitung, Belitung Quartz, Ballclay Bantur, Bentonite, and Talk with a simple casting method. The block bar of the molds was burned at four temperature variations, i.e. 850, 900, 1000, and 1200 oC. From the results of measurements of it water absorption, it was found that the increase in firing temperature from 850 oC to 1200 oC showed a decrease in water absorption from 18.3% to 5.5%, while the measurement of it flexural strength showed an increase in flexural strength of 11.6 kg/cm2 to 19.8 kg/cm2.

An Experimental Study on Structural Concrete Frost-Resistance

2013 ◽  
Vol 448-453 ◽  
pp. 1239-1242 ◽  
Author(s):  
Jin Yang Zhang
Keyword(s):  
Frost Resistance ◽  
Core Sample ◽  
Test Block ◽  
Concrete Core ◽  
Mixture Ratio ◽  
Curing Conditions ◽  
Detection Technology ◽  
Block Test ◽  
Quality Of Structure ◽  
Resistance Performance

In engineering quality inspection and acceptance and evaluation of structural properties, the quality of structure real object is paid more and more attention to by all parties involved in construction. But the structural detection technology and corresponding rules are lagging. Through the use of the same batch of concrete structure and frost resistance of concrete test block test, the results show that for the same concrete mix, the frost resistance of standard preserved test block is better than that of the core samples drilled from concrete; as for the mixture ratio, the forming and curing conditions are exactly same as the concrete, and the preserved test block frost-resistance performance is also superior to that of concrete core-sample.

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