Hippocampus, Amygdala and Basal Ganglia Based Navigation Control

In this paper we present a novel robot navigation system aimed at testing hypotheses about the roles of key brain areas in foraging behavior of rats. The key components of the control network are: 1. a Hippocampus inspired module for spatial localization based on associations between sensory inputs and places; 2. an Amygdala inspired module for the association of values with places and sensory stimuli; 3. a Basal Ganglia inspired module for the selection of actions based on the evaluated sensory inputs. By implementing this Hippocampus-Amygdala-Basal Ganglia based control network with a simulated rat embodiment we intend to test not only our understanding of the individual brain areas but especially the interaction between them. Understanding the neural circuits that allows rats to efficiently forage for food will also help to improve the ability of robots to autonomously evaluate and select navigation targets

The Role of Radioactivities in Astrophysics

I present both a history of radioactivity in astrophysics and an introduction to the major applications of radioactive abundances to astronomy

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Alternative migratory tactics in brown trout (Salmo trutta) are underpinned by divergent regulation of metabolic but not neurological genes

Abstract The occurrence of alternative morphs within populations is common, but the underlying molecular mechanisms remain poorly understood. Many animals, for example, exhibit facultative migration, where two or more alternative migratory tactics (AMTs) coexist within populations. In certain salmonid species, some individuals remain in natal rivers all their lives, while others (in particular, females) migrate to sea for a period of marine growth. Here, we performed transcriptional profiling (“RNA‐seq”) of the brain and liver of male and female brown trout to understand the genes and processes that differentiate between migratory and residency morphs (AMT‐associated genes) and how they may differ in expression between the sexes. We found tissue‐specific differences with a greater number of genes expressed differentially in the liver (n = 867 genes) compared with the brain (n = 10) between the morphs. Genes with increased expression in resident livers were enriched for Gene Ontology terms associated with metabolic processes, highlighting key molecular–genetic pathways underlying the energetic requirements associated with divergent migratory tactics. In contrast, smolt‐biased genes were enriched for biological processes such as response to cytokines, suggestive of possible immune function differences between smolts and residents. Finally, we identified evidence of sex‐biased gene expression for AMT‐associated genes in the liver (n = 12) but not the brain. Collectively, our results provide insights into tissue‐specific gene expression underlying the production of alternative life histories within and between the sexes, and point toward a key role for metabolic processes in the liver in mediating divergent physiological trajectories of migrants versus residents