Coordination when there are restricted and unrestricted options

One might expect that, in pure coordination games, coordination would become less frequent as the number of options increases. Contrary to this expectation, we report an experiment which found more frequent coordination when the option set was unrestricted than when it was restricted. To try to explain this result, we develop a method for eliciting the general rules that subjects use to identify salient options in restricted and unrestricted sets. We find that each such rule, if used by all subjects, would generate greater coordination in restricted sets. However, subjects tend to apply different rules to restricted and unrestricted sets

Proprietary Reasons and Joint Action

Some of the reasons one acts on in joint action are shared with fellow participants. But others are proprietary: reasons of one’s own that have no direct practical significance for other participants. The compatibility of joint action with proprietary reasons serves to distinguish the former from other forms of collective agency; moreover, it is arguably a desirable feature of joint action. Advocates of “team reasoning” link the special collective intention individual participants have when acting together with a distinctive form of practical reasoning that purports to put individuals in touch with group or collective reasons. Such views entail the surprising conclusion that one cannot engage in joint action for proprietary reasons. Suppose we understand the contrast between minimal and robust forms of joint action in terms of the extent to which participants act on proprietary reasons as opposed to shared reasons. Then, if the team reasoning view of joint intention and action is correct, it makes no sense to talk of minimal joint action. As soon as the reason for which one participates is proprietary, then one is not, on this view, genuinely engaged in joint action

Comparative effects of verapamil and nitroprusside on left ventricular function in patients with hypertension

AbstractThe effects of verapamil were compared with those of nitroprusside at matched mean arterial pressures and heart rates in 10 symptomatic hypertensive patients during cardiac catheterization. Simultaneous radionuclide angiography and micromanometer pressure measurements were obtained to assess left ventricular pressure-volume relations. Compared with control conditions, verapamil increased left ventricular end-diastolic volume index from 57 ± 16 to 70 ± 28 ml/m2 (p = 0.05) without a significant increase in left ventricular end-diastolic pressure (from 10 ± 4 to 13 ± 6 mm Hg). Despite a downward and rightward shift in the end-systolic pressure-volume relation indicating negative inotropic effects, ejection fraction did not decrease significantly (from 52 ± 9% to 46 ± 9%); cardiac index and stroke volume index remained unchanged. The change in stroke volume index with verapamil was directly related to the magnitude of change in end-diastolic volume index (r = 0.82, p < 0.005), suggesting that the increase in enddiastolic volume did not arise purely from negative inotropic effects. Systemic vascular resistance index decreased from 42 ± 8 to 34 ± 7 mm Hg-min-m2/liter (p < 0.05).In contrast, nitroprusside decreased left ventricular end-diastolic volume index from 57 ± 16 to 41 ± 10 ml/m2 (p < 0.05), cardiac index from 3.2 ± 0.7 to 2.8 ± 0.6 liters/min per m2 (p < 0.05) and stroke volume index from 28 ± 6 to 24 ± 5 ml/m2 (p < 0.01), with no change in systemic vascular resistance index (40 ± 10 mm Hg·min·m2). The end-systolic pressure-volume relation shifted downward and leftward in all patients, stemming from altered left ventricular loading.Thus, in equihypotensive doses, verapamil and nitroprusside have markedly different effects on left ventricular function. The peripheral vasodilation and apparent improvement in left ventricular filling during verapamil balanced the negative inotropic effects, resulting in maintenance of stroke volume and cardiac index. The primary hypotensive effect of verapamil was a decrease in systemic vascular resistance, whereas that of nitroprusside was a decrease in cardiac index stemming from reduced left ventricular preload

Syncytial Hepatitis of Tilapia (Oreochromis niloticus L.) is Associated With Orthomyxovirus-Like Virions in Hepatocytes

Using transmission electron microscopy (TEM), the presented work expands on the ultrastructural findings of an earlier report on “syncytial hepatitis,” a novel disease of tilapia (SHT). Briefly, TEM confirmed the presence of an orthomyxovirus-like virus within the diseased hepatocytes but not within the endothelium. This was supported by observing extracellular and intracellular (mostly intraendosomal), 60–100 nm round virions with a trilaminar capsid containing up to 7 electron-dense aggregates. Other patterns noted included enveloped or filamentous virions and virion-containing cytoplasmic membrane folds, suggestive of endocytosis. Patterns atypical for orthymyxovirus included the formation of syncytia and the presence of virions within the perinuclear cisternae (suspected to be the Golgi apparatus). The ultrastructural morphology of SHT-associated virions is similar to that previously reported for tilapia lake virus (TiLV). A genetic homology was investigated using the available reverse transcriptase polymerase chain reaction (RT-PCR) probes for TiLV and comparing clinically sick with clinically normal fish and negative controls. By RT-PCR analysis, viral nucleic acid was detected only in diseased fish. Taken together, these findings strongly suggest that a virus is causally associated with SHT, that this virus shares ultrastructural features with orthomyxoviruses, and it presents with partial genetic homology with TiLV (190 nucleotides). </jats:p

Discovery of an unrecognized nidovirus associated with granulomatous hepatitis in rainbow trout

Rainbow trout (Oncorhynchus mykiss) is the principal species of inland-farmed fish in the Western hemisphere. Recently, we diagnosed in farmed rainbow trout a disease in which the hallmark is granulomatous-like hepatitis. No biotic agents could be isolated from lesions. Still, unbiased high-throughput sequencing and bioinformatics analyses revealed the presence of a novel piscine nidovirus that we named “Trout Granulomatous Virus” (TGV). TGV genome (28,767 nucleotides long) is predicted to encode non-structural (1a and 1 ab) and structural (S, M, and N) proteins that resemble proteins of other known piscine nidoviruses. High loads of TGV transcripts were detected by quantitative RT-PCR in diseased fish and visualized in hepatic granulomatous sites by fluorescence in situ hybridization. Transmission electron microscopy (TEM) revealed coronavirus-like particles in these lesions. Together, these analyses corroborated the association of TGV with the lesions. The identification and detection of TGV provide means to control TGV spread in trout populations

Team Reasoning and Collective Intentionality

Different versions of the idea that individualism about agency is the root of standard game theoretical puzzles have been defended by Regan 1980, Bacharach (Research in Economics 53: 117–147, 1999), Hurley (Behavioral and Brain Sciences 26: 264–265, 2003), Sugden (Philosophical Explorations 6(3):165–181, 2003), and Tuomela 2013, among others. While collectivistic game theorists like Michael Bacharach provide formal frameworks designed to avert some of the standard dilemmas, philosophers of collective action like Raimo Tuomela aim at substantive accounts of collective action that may explain how agents overcoming such social dilemmas would be motivated. This paper focuses on the conditions on collective action and intention that need to be fulfilled for Bacharach’s “team reasoning” to occur. Two influential approaches to collective action are related to the idea of team reasoning: Michael Bratman’s theory of shared intention and Raimo Tuomela’s theory of a we-mode of intending. I argue that neither captures the “agency transformation” that team reasoning requires. That might be an acceptable conclusion for Bratman but more problematic for Tuomela, who claims that Bacharach’s results support his theory. I sketch an alternative framework in which the perspectival element that is required for team reasoning - the ‘we-perspective’ - can be understood and functionally characterized in relation to the traditional distinction between mode and content of intentional states. I claim that the latter understanding of a collective perspective provides the right kind of philosophical background for team reasoning, and I discuss some implications in relation to Tuomela’s assumption that switching between individual and collective perspectives can be a matter of rational choice

The Effects of Social Ties on Coordination: Conceptual Foundations for an Empirical Analysis

International audienceThis paper investigates the influence that social ties can have on behavior. After defining the concept of social ties that we consider, we introduce an original model of social ties. The impact of such ties on social preferences is studied in a coordination game with outside option. We provide a detailed game theoretical analysis of this game while considering various types of players, i.e., self-interest maximizing, inequity averse, and fair agents. In addition to these approaches that require strategic reasoning in order to reach some equilibrium, we also present an alternative hypothesis that relies on the concept of team reasoning. After having discussed the differences between the latter and our model of social ties, we show how an experiment can be designed so as to discriminate among the models presented in the paper