Perceptions of Cooperation in a Longitudinal Social Dilemma

Most social dilemma studies of communication’s effects on cooperation are based on laboratory results with trivial incentives. Studies of real-life social dilemmas with nontrivial rewards are needed to extend the generality of laboratory results. Perceptions of cooperation on a group product (weekly group essay) were examined as a public goods dilemma embedded in a longitudinal study of groups using either face-to-face or computer-mediated communication. Perceptions of cooperation increased over time, whereas measures of group identity did not. No media effect on perceptions of cooperation was observed. Several predictors of late perceptions of cooperation were examined, but only early perception of cooperation was significant. Results are discussed with respect to several current hypotheses regarding communication and cooperation in social dilemmas.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Protogalactic Extension of the Parker Bound

We extend the Parker bound on the galactic flux $\cal F$ of magnetic monopoles. By requiring that a small initial seed field must survive the collapse of the protogalaxy, before any regenerative dynamo effects become significant, we develop a stronger bound. The survival and continued growth of an initial galactic seed field $\leq 10^{-9}$G demand that ${\cal F} \leq 5 \times 10^{-21} (m/10^{17} {GeV}) {cm}^{-2} {sec}^{-1} {sr}^{-1}$. For a given monopole mass, this bound is four and a half orders of magnitude more stringent than the previous `extended Parker bound', but is more speculative as it depends on assumptions about the behavior of magnetic fields during protogalactic collapse. For monopoles which do not overclose the Universe ($\Omega_m <1$), the maximum flux allowed is now $8 \times 10^{-19}$ cm^{-2} s^{-1} sr^{-1}, a factor of 150 lower than the maximum flux allowed by the extended Parker bound.Comment: 9 pages, 1 eps figur

On the variation of the gauge couplings during inflation

It is shown that the evolution of the (Abelian) gauge coupling during an inflationary phase of de Sitter type drives the growth of the two-point function of the magnetic inhomogeneities. After examining the constraints on the variation of the gauge coupling arising in a standard model of inflationary and post-inflationary evolution, magnetohydrodynamical equations are generalized to the case of time evolving gauge coupling. It is argued that large scale magnetic fields can be copiously generated. Other possible implications of the model are outlined.Comment: 5 pages in RevTex style, one figur

Monopolium: the key to monopoles

Dirac showed that the existence of one magnetic pole in the universe could offer an explanation for the discrete nature of the electric charge. Magnetic poles appear naturally in most Grand Unified Theories. Their discovery would be of greatest importance for particle physics and cosmology. The intense experimental search carried thus far has not met with success. Moreover, if the monopoles are very massive their production is outside the range of present day facilities. A way out of this impasse would be if the monopoles bind to form monopolium, a monopole- antimonopole bound state, which is so strongly bound, that it has a relatively small mass. Under these circumstances it could be produced with present day facilities and the existence of monopoles could be indirectly proven. We study the feasibility of detecting monopolium in present and future accelerators

Categorizing Different Approaches to the Cosmological Constant Problem

We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future reference. We find that they all can be classified into five different schemes of which we indicate the advantages and drawbacks. Besides, we add a new approach based on a symmetry principle mapping real to imaginary spacetime.Comment: updated version, accepted for publicatio

A Kinematical Approach to Conformal Cosmology

We present an alternative cosmology based on conformal gravity, as originally introduced by H. Weyl and recently revisited by P. Mannheim and D. Kazanas. Unlike past similar attempts our approach is a purely kinematical application of the conformal symmetry to the Universe, through a critical reanalysis of fundamental astrophysical observations, such as the cosmological redshift and others. As a result of this novel approach we obtain a closed-form expression for the cosmic scale factor R(t) and a revised interpretation of the space-time coordinates usually employed in cosmology. New fundamental cosmological parameters are introduced and evaluated. This emerging new cosmology does not seem to possess any of the controversial features of the current standard model, such as the presence of dark matter, dark energy or of a cosmological constant, the existence of the horizon problem or of an inflationary phase. Comparing our results with current conformal cosmologies in the literature, we note that our kinematic cosmology is equivalent to conformal gravity with a cosmological constant at late (or early) cosmological times. The cosmic scale factor and the evolution of the Universe are described in terms of several dimensionless quantities, among which a new cosmological variable delta emerges as a natural cosmic time. The mathematical connections between all these quantities are described in details and a relationship is established with the original kinematic cosmology by L. Infeld and A. Schild. The mathematical foundations of our kinematical conformal cosmology will need to be checked against current astrophysical experimental data, before this new model can become a viable alternative to the standard theory.Comment: Improved version, with minor changes. 58 pages, including 7 figures and one table. Accepted for publication in General Relativity and Gravitation (GERG

Social mindfulness predicts concern for nature and immigrants across 36 nations

People cooperate every day in ways that range from largescale contributions that mitigate climatechange to simple actions such as leaving another individual with choice – known as social mindfulness.It is not yet clear whether and how these complex and more simple forms of cooperation relate. Priorwork has found that countries with individuals who made more socially mindful choices were linked toa higher country environmental performance – a proxy for complex cooperation. Here we replicatedthis initial finding in 41 samples around the world, demonstrating the robustness of the associationbetween social mindfulness and environmental performance, and substantially built on it to show thisrelationship extended to a wide range of complex cooperative indices, tied closely to many currentsocietal issues. We found that greater social mindfulness expressed by an individual was related toliving in countries with more social capital, more community participation and reduced prejudicetowards immigrants. Our findings speak to the symbiotic relationship between simple and morecomplex forms of cooperation in societies.Social decision makin

In-vitro venous prostacyclin production, plasma 6-keto-prostaglandin F1 alpha concentrations, and diabetic retinopathy.

Previous studies have shown that vessels from diabetics produce less prostacyclin in vitro than those from normal controls. To determine whether this decreased production is related to complications elective biopsy of a superficial forearm vein was performed on 12 insulin-dependent male diabetics, six with nil or minimal and six with proliferative retinopathy, and seven male controls. Vein segments from the diabetics and controls produced similar amounts of prostacyclin in vitro (medians 0.11 and 0.19 ng/mg tissue respectively), but the segments from the diabetics with nil or minimal retinopathy produced less than those from the diabetics with proliferative retinopathy (medians 0.09 and 0.18 ng/mg respectively). Preoperative plasma immunoreactive concentrations of 6-keto-prostaglandin F1 alpha were not significantly different between the controls and the diabetics (medians 101 and 116 pg/ml respectively). In a separate study, however, 11 diabetics with duration of disease of over 10 years and nil or minimal retinopathy had significantly lower concentrations than a matched group of 16 with background or proliferative retinopathy (medians 79 and 121 pg/ml respectively). These results do not support an association between reduced prostacyclin production and diabetic retinopathy