Multistep direct mechanism in the (p→,He3) inclusive reaction onCo59andNb93at incident energies between 100 and 160 MeV

2007 ◽  
Vol 75 (5) ◽  
Author(s):  
A. A. Cowley ◽  
J. Bezuidenhout ◽  
S. S. Dimitrova ◽  
P. E. Hodgson ◽  
S. V. Förtsch ◽  
...  
Keyword(s):  
Direct Mechanism ◽  
Inclusive Reaction

The Interrelationship between Thromboxane Biosynthesis, Aggregation and 5-Hydroxytryptamine Secretion in Human Platelets in Vitro

1980 ◽  
Vol 43 (01) ◽  
pp. 038-040 ◽  
Author(s):  
L C Best ◽  
T K Holland ◽  
P B B Jones ◽  
R G G Russell
Keyword(s):  
Human Platelet ◽  
Human Platelets ◽  
Dense Granule ◽  
Thromboxane B2 ◽  
Essential Requirement ◽  
Direct Mechanism ◽  
Thromboxane Synthetase ◽  
Thromboxane Production ◽  
Higher Doses

SummaryPlatelet aggregation, secretion of 5-hydroxy tryptamine and production of thromboxane B2 were monitored simultaneously in human platelet suspensions in the absence and presence of cyclooxygenase or thromboxane synthetase inhibitors. Aggregation, secretion and thromboxane B2 formation in response to either sodium arachidonate or epinephrine were blocked by aspirin or by 1-N-butyl imidazole suggesting that thromboxane biosynthesis was an essential requirement for platelet activation by these agents. In contrast, thrombin and collagen could apparently induce aggregation and secretion via two pathways: at low doses involving thromboxane production, but at higher doses by a direct mechanism independent of thromboxane biosynthesis. In the case of ADP, inhibition of thromboxane production blocked secretion but had little effect on aggregation, indicating that secretion was probably dependent on thromboxane biosynthesis which probably occurred as a result of aggregation. Thus it appears that although the processes of thromboxane production, release of dense granule constituents and aggregation may often be intimately linked, each process can occur independently of the other, depending upon the stimulus used.

scholarly journals Characterising scoring rules by their solution in iteratively undominated strategies

2021 ◽  
Author(s):  
Christian Basteck
Keyword(s):  
Monotonicity Property ◽  
Scoring Rules ◽  
The Other ◽  
Approval Voting ◽  
Property A ◽  
Borda Rule ◽  
Scoring Rule ◽  
Direct Mechanism ◽  
Social Choice Correspondence ◽  
Choice Correspondence

AbstractWe characterize voting procedures according to the social choice correspondence they implement when voters cast ballots strategically, applying iteratively undominated strategies. In elections with three candidates, the Borda Rule is the unique positional scoring rule that satisfies unanimity (U) (i.e., elects a candidate whenever it is unanimously preferred) and is majoritarian after eliminating a worst candidate (MEW)(i.e., if there is a unanimously disliked candidate, the majority-preferred among the other two is elected). In a larger class of rules, Approval Voting is characterized by a single axiom that implies both U and MEW but is weaker than Condorcet-consistency (CON)—it is the only direct mechanism scoring rule that is majoritarian after eliminating a Pareto-dominated candidate (MEPD)(i.e., if there is a Pareto-dominated candidate, the majority-preferred among the other two is elected); among all finite scoring rules that satisfy MEPD, Approval Voting is the most decisive. However, it fails a desirable monotonicity property: a candidate that is elected for some preference profile, may lose the election once she gains further in popularity. In contrast, the Borda Rule is the unique direct mechanism scoring rule that satisfies U, MEW and monotonicity (MON). There exists no direct mechanism scoring rule that satisfies both MEPD and MON and no finite scoring rule satisfying CON.

Direct Mechanism of the First Carbon-Carbon Bond Formation in the Methanol-to-Hydrocarbons Process

2017 ◽  
Vol 129 (31) ◽  
pp. 9167-9171 ◽  
Author(s):  
Xinqiang Wu ◽  
Shutao Xu ◽  
Wenna Zhang ◽  
Jindou Huang ◽  
Jinzhe Li ◽  
...  
Keyword(s):  
Bond Formation ◽  
Carbon Bond ◽  
Direct Mechanism ◽  
Methanol To Hydrocarbons ◽  
Carbon Carbon Bond

Protein phosphatase 2A potentiates activity of promoters containing AP-1-binding elements

1993 ◽  
Vol 13 (4) ◽  
pp. 2104-2112
Author(s):  
A S Alberts ◽  
T Deng ◽  
A Lin ◽  
J L Meinkoth ◽  
A Schönthal ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Protein Phosphatase ◽  
Signal Transduction Pathways ◽  
Marker Genes ◽  
Direct Mechanism ◽  
Phosphatase 2A ◽  
Beta Galactosidase ◽  
Regulatory Sites

The involvement of serine/threonine protein phosphatases in signaling pathways which modulate the activity of the transcription factor AP-1 was examined. Purified protein phosphatase types 1 (PP1) and 2A (PP2A) were microinjected into cell lines containing stably transfected lacZ marker genes under the control of an enhancer recognized by AP-1. Microinjection of PP2A potentiated serum-stimulated beta-galactosidase expression from the AP-1-regulated promoter. Similarly, transient expression of the PP2A catalytic subunit with c-Jun resulted in a synergistic transactivation of an AP-1-regulated reporter gene. PP2A, but not PP1, potentiated serum-induced c-Jun expression, which has been previously shown to be autoregulated by AP-1 itself. Consistent with these results, PP2A dephosphorylated c-Jun on negative regulatory sites in vitro, suggesting one possible direct mechanism for the effects of PP2A on AP-1 activity. Microinjection of PP2A had no effect on cyclic AMP (cAMP)-induced expression of a reporter gene containing a cAMP-regulated promoter, while PP1 injection abolished cAMP-induced gene expression. Taken together, these results suggest a specific role for PP2A in signal transduction pathways that regulate AP-1 activity and c-Jun expression.

scholarly journals Resolving the mesospheric nighttime 4.3 µm emission puzzle: comparison of the CO<sub>2</sub>(<i>ν</i><sub>3</sub>) and OH(<i>ν</i>) emission models

2017 ◽  
Vol 17 (16) ◽  
pp. 9751-9760 ◽  
Author(s):  
Peter A. Panka ◽  
Alexander A. Kutepov ◽  
Konstantinos S. Kalogerakis ◽  
Diego Janches ◽  
James M. Russell ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Vibrational Energy ◽  
Lower Thermosphere ◽  
Vibrational Energy Relaxation ◽  
Density Distributions ◽  
Direct Mechanism ◽  
Vibrational Levels ◽  
Emission Models ◽  
The Impact ◽  
Good Agreement

Abstract. In the 1970s, the mechanism of vibrational energy transfer from chemically produced OH(ν) in the nighttime mesosphere to the CO2(ν3) vibration, OH(ν) ⇒ N2(ν) ⇒ CO2(ν3), was proposed. In later studies it was shown that this "direct" mechanism for simulated nighttime 4.3 µm emissions of the mesosphere is not sufficient to explain space observations. In order to better simulate these observations, an additional enhancement is needed that would be equivalent to the production of 2.8–3 N2(1) molecules instead of one N2(1) molecule in each quenching reaction of OH(ν) + N2(0). Recently a new "indirect" channel of the OH(ν) energy transfer to N2(ν) vibrations, OH(ν) ⇒ O(1D) ⇒ N2(ν), was suggested and then confirmed in a laboratory experiment, where its rate for OH(ν = 9) + O(3P) was measured. We studied in detail the impact of the "direct" and "indirect" mechanisms on CO2(ν3) and OH(ν) vibrational level populations and emissions. We also compared our calculations with (a) the SABER/TIMED nighttime 4.3 µm CO2 and OH 1.6 and 2.0 µm limb radiances of the mesosphere–lower thermosphere (MLT) and (b) with ground- and space-based observations of OH(ν) densities in the nighttime mesosphere. We found that the new "indirect" channel provides a strong enhancement of the 4.3 µm CO2 emission, which is comparable to that obtained with the "direct" mechanism alone but assuming an efficiency that is 3 times higher. The model based on the "indirect" channel also produces OH(ν) density distributions which are in good agreement with both SABER limb OH emission observations and ground and space measurements. This is, however, not true for the model which relies on the "direct" mechanism alone. This discrepancy is caused by the lack of an efficient redistribution of the OH(ν) energy from higher vibrational levels emitting at 2.0 µm to lower levels emitting at 1.6 µm. In contrast, the new  indirect  mechanism efficiently removes at least five quanta in each OH(ν ≥ 5) + O(3P) collision and provides the OH(ν) distributions which agree with both SABER limb OH emission observations and ground- and space-based OH(ν) density measurements. This analysis suggests that the important mechanism of the OH(ν) vibrational energy relaxation in the nighttime MLT, which was missing in the emission models of this atmospheric layer, has been finally identified.

scholarly journals THE SUBSTANCE OF AUDITING IN PROJECT SYSTEM

2021 ◽  
Vol 3 (1) ◽  
pp. 1-11
Author(s):  
Ashutosh Kumar Yadav
Keyword(s):  
Project Development ◽  
Development Team ◽  
High Ranking ◽  
Assessment Strategy ◽  
Inclusive Reaction

The estimation of a development is serious to its achievement. Hence, project administrations reflect this characteristic of handling project a critical instrument in completing the objects of the association from side to side project administration. Project audit measures the performance of the project with detail to its obtainable capitals. In other arguments, it offers an all-inclusive reaction on project status. Such reaction allows high-ranking administration to make learnt judgement that will impulse the project in completing its objects. Though, around of the main profits of project auditing are as monitors; assistances progress the performance of the project, improves client and investor approval, saves prices, panels opportunity and circumvent opportunity sidle, offers primary difficult diagnostics, simplifies piece/ cost/ agenda relations, recognizes upcoming prospects for development, estimates performance of the project development team, updates consumer of project status/scenarios and reconfirms possibility of promise to project development. Development examiners are charged with the concern to review the project; for which the project administrator and development team should be helpful in imperative to boost the procedure. The Observing and Assessment Strategy developed prior in the project should be castoff in this workout. Zones of the project where the examiners deficiency to the ability to investigation into auditing System, they can mention for a methodological auditing to be piloted in such zones.

Light-evoked contraction of red absorbing cones in the Xenopus retina is maximally sensitive to green light

1992 ◽  
Vol 8 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Joseph C. Besharse ◽  
Paul Witkovsky
Keyword(s):  
Xenopus Laevis ◽  
Spectral Sensitivity ◽  
Red Light ◽  
Green Light ◽  
Sensitivity Function ◽  
Direct Mechanism ◽  
Sensitivity Experiments ◽  
Light Stimuli ◽  
The Difference ◽  
Spectral Sensitivity Function

AbstractTo test the hypothesis that light-evoked cone contraction in eye cups from Xenopus laevis is controlled through a direct mechanism initiated by the cone's own photopigment, we conducted spectral-sensitivity experiments. We estimate that initiation of contraction of red absorbing cones (611 nm) is 1.5 log units more sensitive to green (533 nm) than red (650 nm) light stimuli. The difference is comparable to that predicted from the spectral-sensitivity function of the green absorbing, principal rod (523 nm). Furthermore, 480-nm and 580-nm stimuli which are absorbed nearly equally by the principal rod have indistinguishable effects on cone contraction. We also found that light blockade of nighttime cone elongation is much more sensitive to green than to red light stimuli. Our observations are inconsistent with the hypothesis tested, and suggest that light-regulated cone motility is controlled through an indirect mechanism initiated primarily by the green absorbing, principal rod.

Activated dissociative chemisorption of methane on Ni(100): a direct mechanism under thermal conditions?

1995 ◽  
Vol 32 (1-2) ◽  
pp. 15-30 ◽  
Author(s):  
B. �lgaard Nielsen ◽  
A. C. Luntz ◽  
P. M. Holmblad ◽  
I. Chorkendorff
Keyword(s):  
Thermal Conditions ◽  
Dissociative Chemisorption ◽  
Direct Mechanism
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