Disruptions in large value payment systems: an experimental approach

This experimental study investigates the behaviour of banks in a large value payment system. More specifically,we look at 1) the reactions of banks to disruptions in the payment system, 2) the way in which the history of disruptions affects the behaviour of banks (path dependency) and 3) the effect of more concentration in the payment system (heterogeneous market versus a homogeneous market). The game used in this experiment is a stylized version of a model of Bech and Garrett (2006) in which each bank can choose between paying in the morning (efficient) or in the afternoon (inefficient). The results show that there is significant path dependency in terms of disruption history. Also the chance of disruption influences the behaviour of the participants. Once the system is moving towards the inefficient equilibrium, it does not easily move back to the efficient one. Furthermore, there is a clear leadership effect in the heterogeneous market

The Behavioral Impact of Emotions in a Power-to-Take Game: An Experimental Study

The power-to-take game is a simple two player game where players are randomly divided into pairs consisting of a take authority and responder. Both players in each pair have earned an income in an individual real effort decision-making experiment preceding the take game. The game consists of two stages. In the first stage, the take authority decides how much of the earned income of the responder that is left after the second stage will be transferred to the take authority (the so-called take rate). In the second stage, the responder can punish the take authority by destroying (part of) his or her earned income. In this experimental study, we are primarily interested in how emotions influence responder behavior. Our findings are the following. (1) A higher take rate significantly increases the intensity of irritation, contempt, and envy, and significantly decreases the intensity of joy and happiness. Since negative emotions are experienced as painful, there is direct hedonic impact. (2) Irritation and contempt drive punishment behavior. (3) There are discontinuous "jumps" in the behavior of responders. They either choose no punishment (destroy nothing) or the highest level of punishment (destroy everything). (4) Expectations have a significant effect on the probability of punishment but not on the intensity of experienced emotion. This last result is explained in terms of norm-related regulation of emotions.Emotions, punishment, expectations, social norms, experiment

Exploring Group Behavior in a Power-to-Take Video Experiment

This paper experimentally explores group decision-making in a two-player power-to-take game. Discussions preceding group decisions are video taped and analyzed. Each subject first earns an income in an individual effort task preceding the game. The game consists of two stages. First, one group can claim any part of the income of the other group (take rate). Then, the latter group can respond by destroying own income. The results show that (1) although group behavior is in line with individual behavior, group behavior depends crucially on the decision rules that subject use to arrive at their group decision; (2) groups ignore the decision rule of their ‘opponents’ and typically view other groups as if they were single agents; (3) perceptions of fairness are prone to the so-called self-serving bias. (4) expectations are often not consistent with actual outcomes.groups, decision rule, fairness, experiment, video

Microwave absorption on a thin film

With the use of a simple model, it is shown that a thin film of contaminant on a microwave window may absorb up to 50% of the incident power, even if the film thickness is only a small fraction of its resistive skin depth. This unexpectedly large amount of absorption is conjectured to have played a significant role in window failure. The temperature rise in a thin film is estimated. © 2003 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71216/2/APPLAB-82-9-1353-1.pd

Heating of Contaminants on Diamond Windows

This paper examines the RF heating of the contaminants on a diamond window. Both heating of an isolated internal graphite impurity, and of a thin film on the window surface, are discussed. Comparison with recent experiments is given. It is found that heating of isolated internal graphite impurities is unlikely to account for diamond window failure. Upon averaging over the entire window, the thin surface film in general absorbs approximately a fraction of one percent of the total incident power. Intense local heating on the surface contaminant is possible, however. © 2003 American Institute of PhysicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87504/2/234_1.pd

The Ohmic heating of particulates in a lossless medium

This paper provides a general theory on the Ohmic dissipation of electromagnetic energy by a spherical particulate that is embedded in a lossless medium. The particulate may possess an arbitrary electrical conductivity, and both the medium and the particulate may assume general values of permittivity and permeability. Under the assumption that the wavelength of the electromagnetic field in the medium is large compared with the particulate size, we provide an accurate account of the degree of Ohmic heating by the radio frequency (rf) electric field and by the rf magnetic field of the electromagnetic field. It is found that, in general, heating by the rf magnetic field is dominant whenever δ<aδ<a, where δδ is the resistive skin depth and aa is the radius of the particulate. Analytic scaling laws in the various regimes are derived, from the static case to very high frequency, and for ratios of δ/aδ∕a ranging from zero to infinity. The calculation is extended to a transient electromagnetic pulse. Also constructed is the loss tangent of the medium, resulting from a distribution of particulates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87599/2/114915_1.pd

Heating of a particulate by radio-frequency electric and magnetic fields

With the use of a highly symmetrical model, the heating of a spherical particulate by a predominantly radio-frequency electric field and by a predominantly rf magnetic field is solved exactly using the Maxwell equations. It is found that, in general, heating by the rf magnetic field is dominant whenever δ<aδ<a, where δδ is the resistive skin depth and aa is the radius of the particulate, which may either be nonmagnetic or magnetic. The known analytic scaling laws in the various regimes are recovered, from the static case to very high frequency, subject to λ≫aλ≫a, where λλ is the free space wavelength of the rf field. The analysis may form a theoretical basis in the heating phenomenology of particulates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70327/2/APPLAB-85-15-3319-1.pd

Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients

Introduction The aim of this study was to investigate whether in-hospital mortality was associated with the administered fraction of oxygen in inspired air (FiO(2)) and achieved arterial partial pressure of oxygen (PaO(2)). Methods This was a retrospective, observational study on data from the first 24 h after admission from 36,307 consecutive patients admitted to 50 Dutch intensive care units (ICUs) and treated with mechanical ventilation. Oxygenation data from all admission days were analysed in a subset of 3,322 patients in 5 ICUs. Results Mean PaO(2) and FiO(2) in the first 24 h after ICU admission were 13.2 kPa (standard deviation (SD) 6.5) and 50% (SD 20%) respectively. Mean PaO(2) and FiO(2) from all admission days were 12.4 kPa (SD 5.5) and 53% (SD 18). Focusing on oxygenation in the first 24 h of admission, in-hospital mortality was shown to be linearly related to FiO(2) value and had a U-shaped relationship with PaO(2) (both lower and higher PaO(2) values were associated with a higher mortality), independent of each other and of Simplified Acute Physiology Score (SAPS) II, age, admission type, reduced Glasgow Coma Scale (GCS) score, and individual ICU. Focusing on the entire ICU stay, in-hospital mortality was independently associated with mean FiO(2) during ICU stay and with the lower two quintiles of mean PaO(2) value during ICU stay. Conclusions Actually achieved PaO(2) values in ICU patients in The Netherlands are higher than generally recommended in the literature. High FiO(2), and both low PaO(2) and high PaO(2) in the first 24 h after admission are independently associated with in-hospital mortality in ICU patients. Future research should study whether this association is causal or merely a reflection of differences in severity of illness insufficiently corrected for in the multivariate analysis

Association between administered oxygen, arterial partial oxygen pressure and mortality in mechanically ventilated intensive care unit patients

Introduction The aim of this study was to investigate whether in-hospital mortality was associated with the administered fraction of oxygen in inspired air (FiO(2)) and achieved arterial partial pressure of oxygen (PaO(2)). Methods This was a retrospective, observational study on data from the first 24 h after admission from 36,307 consecutive patients admitted to 50 Dutch intensive care units (ICUs) and treated with mechanical ventilation. Oxygenation data from all admission days were analysed in a subset of 3,322 patients in 5 ICUs. Results Mean PaO(2) and FiO(2) in the first 24 h after ICU admission were 13.2 kPa (standard deviation (SD) 6.5) and 50% (SD 20%) respectively. Mean PaO(2) and FiO(2) from all admission days were 12.4 kPa (SD 5.5) and 53% (SD 18). Focusing on oxygenation in the first 24 h of admission, in-hospital mortality was shown to be linearly related to FiO(2) value and had a U-shaped relationship with PaO(2) (both lower and higher PaO(2) values were associated with a higher mortality), independent of each other and of Simplified Acute Physiology Score (SAPS) II, age, admission type, reduced Glasgow Coma Scale (GCS) score, and individual ICU. Focusing on the entire ICU stay, in-hospital mortality was independently associated with mean FiO(2) during ICU stay and with the lower two quintiles of mean PaO(2) value during ICU stay. Conclusions Actually achieved PaO(2) values in ICU patients in The Netherlands are higher than generally recommended in the literature. High FiO(2), and both low PaO(2) and high PaO(2) in the first 24 h after admission are independently associated with in-hospital mortality in ICU patients. Future research should study whether this association is causal or merely a reflection of differences in severity of illness insufficiently corrected for in the multivariate analysis

Conjugation of a Toll-Like Receptor Agonist to Glycans of an HIV Native-Like Envelope Trimer Preserves Neutralization Epitopes

Small molecule adjuvants are attractive for enhancing broad protection and durability of immune responses elicited by subunit vaccines. Covalent attachment of an adjuvant to an immunogen is particularly attractive because it simultaneously delivers both entities to antigen presenting cells resulting in more efficient immune activation. There is, however, a lack of methods to conjugate small molecule immune potentiators to viral glycoprotein immunogens without compromising epitope integrity. We describe herein a one-step enzymatic conjugation approach for the covalent attachment of small molecule adjuvants to N-linked glycans of viral glycoproteins. It involves the attachment of an immune potentiator to CMP-Neu5AcN 3 by Cu(I)-catalyzed azide-alkyne 1,3-cycloaddition followed by sialyltransferase-mediated transfer to N-glycans of a viral glycoprotein. The method was employed to modify a native-like HIV envelope trimer with a Toll-like receptor 7/8 agonist. The modification did not compromise Env-trimer recognition by several broadly neutralization antibodies. Electron microscopy confirmed structural integrity of the modified immunogen