The structuring role of artificial structure on fish assemblages in a dammed river of the Pearl River in China

To address the fish use patterns of artificial structures mimicking floating macrophytes deployed in a impounded tributary of the Pearl River, China, field experiments were performed from December 2014 to June 2016 using multi-mesh gillnet. The fish assemblages using artificial structures differ in terms of species richness, abundance, body size, diversity indices, and ecological traits from fish assemblages on natural barren habitats of this river. Overall, fish abundance, species richness, Shannon diversity index, and functional richness were higher at the artificial structures than at the control sites, while fish length and functional evenness was greater at the control sites in comparison to artificial structures. The introduction of artificial structures did not result in statistically significant effects on fish biomass as artificial structures attracted more individuals with smaller size. Seasonal changes of chlorophyll-a and transparency may affect the efficiency of artificial structure in harboring fishes. This study revealed that artificial structures, as synthesized habitats, are effective in acting as a “fish attractor” and an alternative tool to provide new habitats for smaller individuals in a dammed river like the Youjiang River which is a structure-less ecosystem

The structuring role of artificial structure on fish assemblages in a dammed river of the Pearl River in China

To address the fish use patterns of artificial structures mimicking floating macrophytes deployed in a impounded tributary of the Pearl River, China, field experiments were performed from December 2014 to June 2016 using multi-mesh gillnet. The fish assemblages using artificial structures differ in terms of species richness, abundance, body size, diversity indices, and ecological traits from fish assemblages on natural barren habitats of this river. Overall, fish abundance, species richness, Shannon diversity index, and functional richness were higher at the artificial structures than at the control sites, while fish length and functional evenness was greater at the control sites in comparison to artificial structures. The introduction of artificial structures did not result in statistically significant effects on fish biomass as artificial structures attracted more individuals with smaller size. Seasonal changes of chlorophyll-a and transparency may affect the efficiency of artificial structure in harboring fishes. This study revealed that artificial structures, as synthesized habitats, are effective in acting as a “fish attractor” and an alternative tool to provide new habitats for smaller individuals in a dammed river like the Youjiang River which is a structure-less ecosystem

Downregulation of UBE4B promotes CNS axon regrowth and functional recovery after stroke

Summary: The limited intrinsic regrowth capacity of corticospinal axons impedes functional recovery after cortical stroke. Although the mammalian target of rapamycin (mTOR) and p53 pathways have been identified as the key intrinsic pathways regulating CNS axon regrowth, little is known about the key upstream regulatory mechanism by which these two major pathways control CNS axon regrowth. By screening genes that regulate ubiquitin-mediated degradation of the p53 proteins in mice, we found that ubiquitination factor E4B (UBE4B) represses axonal regrowth in retinal ganglion cells and corticospinal neurons. We found that axonal regrowth induced by UBE4B depletion depended on the cooperative activation of p53 and mTOR. Importantly, overexpression of UbV.E4B, a competitive inhibitor of UBE4B, in corticospinal neurons promoted corticospinal axon sprouting and facilitated the recovery of corticospinal axon-dependent function in a cortical stroke model. Thus, our findings provide a translatable strategy for restoring corticospinal tract-dependent functions after cortical stroke