Mapping the Pattern of Essential Neuroendocrine Cells Related to Puberty and VA Opsin Expression Provides Further Insight in the Photoreceptive Regulation of the Brain-Pituitary-Gonadal Axis in Atlantic Salmon (Salmo salar).

In Atlantic salmon (Salmo salar), seasonal photoperiod is shown to regulate the onset of sexual maturation, yet which brain region(s) is involved, and how light information impacts the neuroendocrine system are still not fully understood in teleosts. Detailed knowledge about the photoperiodic regulation of maturation in fish is still missing. In birds, it is shown that gonadotropin-releasing hormone (Gnrh) is located in the same neurons as vertebrate ancient (VA) opsin, suggesting a direct photoreceptive regulation for the onset of sexual maturity. This study presents a comprehensive topographic mapping of gnrh2, gnrh3, kisspeptin 2 (kiss2), gonadotropin-inhibiting hormone (gnih), and VA opsin using in situ hybridization on mature Atlantic salmon brains. Neurons positive for gnrh3 are expressed in the olfactory bulb and ventral telencephalon, while gnrh2-positive neurons are located dorsally in the midbrain tegmentum. Gonadotropin-inhibiting hormone (Gnih)-expressing cell bodies are present in the ventral thalamus and extend caudally to the hypothalamus with kiss2-expressing cells appearing in a lateral position. VA opsin-positive cells are present in the telencephalon, the rostro-dorsal ring of the left habenula, the ventral thalamus, and the midbrain tegmentum. The results show no similar co-location as found in birds, hypothesizing that the photoreceptive modulation of Gnrh in salmon may interact through neuronal networks. The topography analyses of the essential neuroendocrine cells related to sexual maturation in the Atlantic salmon brain show that diencephalic (thalamus, hypothalamus) and midbrain (tegmentum) regions seem central for controlling sexual maturation.

In the shade of a forest status, reputation, and ambiguity in an online microcredit market.

Scholars have long recognized status and reputation as pervasive forces reproducing comparative advantage in social and economic systems. Yet, due in part to methodological challenges, relatively few studies have examined how status and reputation interact. We use data from an online market for peer-to-peer lending to study independent and joint effects of status and reputation on borrowers' success at obtaining loans. First, we find a positive main effect of status, even when reputational signals are reliable and abundant. Second, we find that status matters the most for borrowers with moderate (rather than high or low) reputations, suggesting a curvilinear effect of status x reputation on loans. These results support the idea that status matters not only under conditions of too little information that creates information asymmetry, as typically assumed, but also under conditions of abundant information and too many choices that creates ambiguity about how to evaluate candidates.

Privacy, technology, and norms: the case of Smart Meters.

Norms shift and emerge in response to technological innovation. One such innovation is Smart Meters - components of Smart Grid energy systems capable of minute-to-minute transmission of consumer electricity use information. We integrate theory from sociological research on social norms and privacy to examine how privacy threats affect the demand for and expectations of norms that emerge in response to new technologies, using Smart Meters as a test case. Results from three vignette experiments suggest that increased threats to privacy created by Smart Meters are likely to provoke strong demand for and expectations of norms opposing the technology and that the strength of these normative rules is at least partly conditional on the context. Privacy concerns vary little with actors' demographic characteristics. These findings contribute to theoretical understanding of norm emergence and have practical implications for implementing privacy protections that effectively address concerns of electricity users.

A normative explanation of antisocial punishment.

While much research shows that people punish free-riders, recent studies find evidence that people also engage in antisocial punishment. That is, they sometimes punish those who contribute generously to collective actions. Such sanctioning is puzzling because generous individuals increase the welfare of all group members. When and why are such individuals punished? In this paper, we propose that descriptive norms are part of the explanation. People may sanction those whose behavior is atypical - even when that behavior benefits the group. We test our theory with a laboratory experiment. We examine the effect of descriptive norms on sanctioning of generous and stingy deviants and find that descriptive norms encourage antisocial punishment, but not punishment of free-riders.