Fruit bats as reservoirs of Ebola virus

The first recorded human outbreak of Ebola virus was in 1976, but the wild reservoir of this virus is still unknown. Here we test for Ebola in more than a thousand small vertebrates that were collected during Ebola outbreaks in humans and great apes between 2001 and 2003 in Gabon and the Republic of the Congo. We find evidence of asymptomatic infection by Ebola virus in three species of fruit bat, indicating that these animals may be acting as a reservoir for this deadly virus.     

What are the memory sources of dreaming?

Investigators since Freud have appreciated that memories of the people, places, activities and emotions of daily life are reflected in dreams but are typically so fragmented that their predictability is nil. The mechanisms that translate such memories into dream images remain largely unknown. New research targeting relationships between dreaming, memory and the hippocampus is producing a new theory to explain how, why and when we dream of waking life events.     

一种新的植物枝条弯曲生成算法

枝条弯曲模拟对于形象地绘制模特图形很重要。从计算机图形学的角度出发,提出了一种计算枝条弯曲形状的简易力学模型,实现了基于“双尺度自动机模型”的枝条弯曲算法。该算法虽然所需参数少,但能有效地生成自然逼真的枝条弯曲形状,并且能反映植物在生长中枝条的动态弯曲过程。文中通过几个枝条弯曲的例子验证了算法的有效性。     

Astrocladistics: A Phylogenetic Analysis of Galaxy Evolution I. Character Evolutions and Galaxy Histories

This series of papers is intended to present astrocladistics in some detail and evaluate this methodology in reconstructing phylogenies of galaxies. Being based on the evolution of all the characters describing galaxies, it is an objective way of understanding galaxy diversity through evolutionary relationships. In this first paper, we present the basic steps of a cladistic analysis and show both theoretically and practically that it can be applied to galaxies. For illustration, we use a sample of 50 simulated galaxies taken from the GALICS database, which are described by 91 observables (dynamics, masses and luminosities). These 50 simulated galaxies are indeed 10 different galaxies taken at 5 cosmological epochs, and they are free of merger events. The astrocladistic analysis easily reconstructs the true chronology of evolution relationships within this sample. It also demonstrates that burst characters are not relevant for galaxy evolution as a whole. A companion paper is devoted to the formalization of the concepts of formation and diversification in galaxy evolution.     

Melatonin receptors limit dopamine reuptake by regulating dopamine transporter cell-surface exposure

Melatonin, a neuro-hormone released by the pineal gland, has multiple effects in the central nervous system including the regulation of dopamine (DA) levels, but how melatonin accomplishes this task is not clear. Here, we show that melatonin MT₁ and MT₂ receptors co-immunoprecipitate with the DA transporter (DAT) in mouse striatal synaptosomes. Increased DA re-uptake and decreased amphetamine-induced locomotor activity were observed in the striatum of mice with targeted deletion of MT₁ or MT₂ receptors. In vitro experiments confirmed the interactions and recapitulated the inhibitory effect of melatonin receptors on DA re-uptake. Melatonin receptors retained DAT in the endoplasmic reticulum in its immature non-glycosylated form. In conclusion, we reveal one of the first molecular complexes between G protein-coupled receptors (MT₁ and MT₂) and transporters (DAT) in which melatonin receptors regulate the availability of DAT at the plasma membrane, thus limiting the striatal DA re-uptake capacity in mice.     

Ultrastructural and quantitative analysis of the lipid droplet clustering induced by hepatitis C virus core protein

Hepatitis C virus (HCV) release is linked to the formation of lipid droplet (LD) clusters in the perinuclear area of infected cells, induced by the core protein. We used electron microscopy (EM) to monitor and compare the number and size of LD in cells producing the mature and immature forms of the HCV core protein, and 3D EM to reconstruct whole cells producing the mature core protein. Only the mature protein coated the LD and induced their clustering and emergence from endoplasmic reticulum membranes enriched in this protein. We found no particular association between LD clusters and the centrosome in reconstructed cells. The LD clustering induced by the mature core protein was associated with an increase in LD synthesis potentially due, at least in part, to the ability of this protein to coat the LD. These observations provide useful information for further studies of the mechanisms involved in HCV-induced steatosis.