1. Once upon a time, the elephant and the mosquito were good friends. The elephant was not so fat and big as it is now. The mosquito was not so thin and small as it is now. One day, the elephant advised the mosquito t...1. Once upon a time, the elephant and the mosquito were good friends. The elephant was not so fat and big as it is now. The mosquito was not so thin and small as it is now. One day, the elephant advised the mosquito to settle down with him where there were forests and lakes.展开更多
Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna ...Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna zone in Nigeria. Tree mean specific gravity averaged 0.37; wood at the base had significant higher specific gravity than those at the top while it increased from pith to bark. For extractive content mean value was 1.20% for wood and 1.72% for bark; i[t varied significantly between trees and from base of the tree to the top and from pith to the bark. Extractive content at the butt and breast height is more than double of the value at the top of the tree. The high extractive content at the base is similar to high specific gravity observed for wood samples from the base. Extractive content of the bast was significantly higher than that of the wood. The low specific gravity show possible suitability of the species for paper making in Nigerian paper mills. The wood of Sterculia setigera showed a significant variation between- and within-trees in the two properties considered, though the wood is light with low extractive content; it is however a potential raw material for large scale pulpwood production in Nigeria.展开更多
It is widely accepted that body weight and adipose mass are tightly regulated by homeostatic mechanisms, in which leptin plays a critical role through hypothalamic pathways, and obesity is a result of homeostatic diso...It is widely accepted that body weight and adipose mass are tightly regulated by homeostatic mechanisms, in which leptin plays a critical role through hypothalamic pathways, and obesity is a result of homeostatic disorder. However, in C57BL/6J mice, we found that Rcan2 increases food intake and plays an important role in the develop- ment of age- and diet-induced obesity through a leptin-independent mechanism. RCAN2 was initially identified as a thyroid hormone （T3）-responsive gene in human fibroblasts. Expression of RCAN2 is regulated by T3 through the PI3K-Akt/PKB-mTOR-Rps6kbl signaling pathway. Intriguingly, both Rcan2-/- and Rps6kb1-/- mutations were re- ported to result in lean phenotypes in mice. In this study we compared the effects of these two mutations on growth and body weight in C57BL/6J mice. We observed reduced body weight and lower fat mass in both Rcan2-/- and Rps6kb1-/- mice compared to the wild-type mice, and we reported other differences unique to either the Rcan2-/- or Rps6kb1-/- mice. Firstly, loss of Rcan2 does not directly alter body length; however, Rcan2-/- mice exhibit reduced food intake. In contrast, Rps6kb1-/- mice exhibit abnormal embryonic development, which leads to smaller body size and reduced food intake in adulthood. Secondly, when fed a normal chow diet, Rcan2-/- mice weigh significantly more than Rps6kb1-/- mice, but both Rcan2-/- and Rps6kbl-/- mice develop similar amounts of epididymal fat. On a high-fat diet, Rcan2-/- mice gain body weight and fat mass at slower rates than Rps6kb1-/- mice. Finally, using the double-knockout mice （Rcan2-/- Rps6kb1-/-）, we demonstrate that concurrent loss of Rcan2and Rps6kbl has an additive effect on body weight reduction in C57BL/6J mice. Our data suggest that Rcan2 and Rps6kbl mutations both affect growth and body weight of mice, though likely through different mechanisms.展开更多
文摘1. Once upon a time, the elephant and the mosquito were good friends. The elephant was not so fat and big as it is now. The mosquito was not so thin and small as it is now. One day, the elephant advised the mosquito to settle down with him where there were forests and lakes.
文摘Variations of wood specific gravity and extractive contents from pith to bark and from base to the top of tree were investigated in a 14-year-old commercial pulpwood species Sterculia setigera Del. Growing in savanna zone in Nigeria. Tree mean specific gravity averaged 0.37; wood at the base had significant higher specific gravity than those at the top while it increased from pith to bark. For extractive content mean value was 1.20% for wood and 1.72% for bark; i[t varied significantly between trees and from base of the tree to the top and from pith to the bark. Extractive content at the butt and breast height is more than double of the value at the top of the tree. The high extractive content at the base is similar to high specific gravity observed for wood samples from the base. Extractive content of the bast was significantly higher than that of the wood. The low specific gravity show possible suitability of the species for paper making in Nigerian paper mills. The wood of Sterculia setigera showed a significant variation between- and within-trees in the two properties considered, though the wood is light with low extractive content; it is however a potential raw material for large scale pulpwood production in Nigeria.
基金Project supported by the National Natural Science Foundation of China(Nos.31140091 and 31371495)Shandong Natural Science Foundation(No.ZR2013CM040),China
文摘It is widely accepted that body weight and adipose mass are tightly regulated by homeostatic mechanisms, in which leptin plays a critical role through hypothalamic pathways, and obesity is a result of homeostatic disorder. However, in C57BL/6J mice, we found that Rcan2 increases food intake and plays an important role in the develop- ment of age- and diet-induced obesity through a leptin-independent mechanism. RCAN2 was initially identified as a thyroid hormone （T3）-responsive gene in human fibroblasts. Expression of RCAN2 is regulated by T3 through the PI3K-Akt/PKB-mTOR-Rps6kbl signaling pathway. Intriguingly, both Rcan2-/- and Rps6kb1-/- mutations were re- ported to result in lean phenotypes in mice. In this study we compared the effects of these two mutations on growth and body weight in C57BL/6J mice. We observed reduced body weight and lower fat mass in both Rcan2-/- and Rps6kb1-/- mice compared to the wild-type mice, and we reported other differences unique to either the Rcan2-/- or Rps6kb1-/- mice. Firstly, loss of Rcan2 does not directly alter body length; however, Rcan2-/- mice exhibit reduced food intake. In contrast, Rps6kb1-/- mice exhibit abnormal embryonic development, which leads to smaller body size and reduced food intake in adulthood. Secondly, when fed a normal chow diet, Rcan2-/- mice weigh significantly more than Rps6kb1-/- mice, but both Rcan2-/- and Rps6kbl-/- mice develop similar amounts of epididymal fat. On a high-fat diet, Rcan2-/- mice gain body weight and fat mass at slower rates than Rps6kb1-/- mice. Finally, using the double-knockout mice （Rcan2-/- Rps6kb1-/-）, we demonstrate that concurrent loss of Rcan2and Rps6kbl has an additive effect on body weight reduction in C57BL/6J mice. Our data suggest that Rcan2 and Rps6kbl mutations both affect growth and body weight of mice, though likely through different mechanisms.
