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71.
The recovery process of fallow stands in the mountainous region of Northwestern Vietnam was studied, based on a chronosequence of 1–26-year-old secondary forests after intensive shifting cultivation. The number of species present in a 26-year-old secondary forest attained 49% of the 72 species present in an old-growth forest. Total stem density decreased gradually from 172,500 ha−1 in a 3-year-old forest to 24,600 ha−1 in the 26-year-old stand, but stem density of larger trees (diameter at breast height (D) ≥ 5 cm) increased from 60 ha−1 in a 7-year-old to 960 ha−1 in the 26-year-old forests, which was similar to that of an old-growth forest. Annual biomass increment of the 26-year-old stand was 4.2 Mg ha−1 year−1. A saturation curve was fitted to biomass accumulation in secondary forests. After an estimated time of 60 years, a secondary forest can achieve 80% of the biomass of old-growth forests (240 Mg ha−1). Species diversity expressed by Shannon Index shows that it takes 60 years for a secondary forest in fallow to achieve a plant species diversity similar to that of old-growth forests. 相似文献
72.
Fish Physiology and Biochemistry - This study aimed to examine the effects of dietary digested soybean protein (DSP) and taurine on bile acid (BA) level, lipase activity, lipid apparent... 相似文献
73.
Hyo-jin Chung Wook-hun Chung Jae-Hoon Lee Dai-Jung Chung Wo-Jong Yang A-Jin Lee Chi-Bong Choi Hwa-Seok Chang Dae-Hyun Kim Hyun Jung Suh Dong-Hun Lee Soo-Han Hwang Sun Hee Do Hwi-Yool Kim 《Journal of veterinary science (Suw?n-si, Korea)》2016,17(1):97-102
We induced percutaneous spinal cord injuries (SCI) using a balloon catheter in 45 rats and transplanted human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) at the injury site. Locomotor function was significantly improved in hUCB-MSCs transplanted groups. Quantitative ELISA of extract from entire injured spinal cord showed increased expression of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and neurotrophin-3 (NT-3). Our results show that treatment of SCI with hUCB-MSCs can improve locomotor functions, and suggest that increased levels of BDNF, NGF and NT-3 in the injured spinal cord were the main therapeutic effect. 相似文献
74.
Heo WD Inoue T Park WS Kim ML Park BO Wandless TJ Meyer T 《Science (New York, N.Y.)》2006,314(5804):1458-1461
Many signaling, cytoskeletal, and transport proteins have to be localized to the plasma membrane (PM) in order to carry out their function. We surveyed PM-targeting mechanisms by imaging the subcellular localization of 125 fluorescent protein-conjugated Ras, Rab, Arf, and Rho proteins. Out of 48 proteins that were PM-localized, 37 contained clusters of positively charged amino acids. To test whether these polybasic clusters bind negatively charged phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] lipids, we developed a chemical phosphatase activation method to deplete PM PI(4,5)P2. Unexpectedly, proteins with polybasic clusters dissociated from the PM only when both PI(4,5)P2 and phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P3] were depleted, arguing that both lipid second messengers jointly regulate PM targeting. 相似文献
75.
Tennessen JA Bigham AW O'Connor TD Fu W Kenny EE Gravel S McGee S Do R Liu X Jun G Kang HM Jordan D Leal SM Gabriel S Rieder MJ Abecasis G Altshuler D Nickerson DA Boerwinkle E Sunyaev S Bustamante CD Bamshad MJ Akey JM;Broad GO;Seattle GO;NHLBI Exome Sequencing Project 《Science (New York, N.Y.)》2012,337(6090):64-69
As a first step toward understanding how rare variants contribute to risk for complex diseases, we sequenced 15,585 human protein-coding genes to an average median depth of 111× in 2440 individuals of European (n = 1351) and African (n = 1088) ancestry. We identified over 500,000 single-nucleotide variants (SNVs), the majority of which were rare (86% with a minor allele frequency less than 0.5%), previously unknown (82%), and population-specific (82%). On average, 2.3% of the 13,595 SNVs each person carried were predicted to affect protein function of ~313 genes per genome, and ~95.7% of SNVs predicted to be functionally important were rare. This excess of rare functional variants is due to the combined effects of explosive, recent accelerated population growth and weak purifying selection. Furthermore, we show that large sample sizes will be required to associate rare variants with complex traits. 相似文献
76.
77.
Sun-Gil Do Jun-Hong Park Hajin Nam Jin-Bong Kim Jae-Yong Lee Yang-Seok Oh Jun-Gyo Suh 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(4):339-344
Components of silk including silk fibroin have long been used as anti-diabetic remedies in oriental medicine. However, detailed mechanisms underlying these anti-diabetic effects remain unclear. In this study, we examined the anti-diabetic activity of silk fibroin hydrolysate (SFH) in C57BL/KsJ-db/db (db/db) mice, a well-known animal model of non-insulin dependent diabetes mellitus. When the db/db mice were administered SFH in drinking water for 6 weeks, hyperglycemia in the animals gradually disappeared and the level of glycosylated hemoglobin decreased, indicating that SFH plays important role in reducing the symptoms of diabetes. In addition, SFH-treated db/db mice exhibited improved glucose tolerance with increased plasma insulin levels. Immunohistochemical and morphological analyses showed that SFH up-regulated insulin production by increasing pancreatic β cell mass in the mice. In summary, our results suggest that SFH exerts anti-diabetic effects by increasing pancreatic β cell mass in a non-insulin dependent diabetes mellitus mouse model. 相似文献
78.
Using new egg parasitoids (Trichogramma spp.) to improve integrated management against Tuta absoluta
H. Do Thi Khanh A. Chailleux M. Tiradon N. Desneux E. Colombel E. Tabone 《EPPO Bulletin》2012,42(2):249-254
This study is the first step of the TutaPI program (2011–13) to decrease the costs of Integrated Pest Management (IPM) strategies against Tuta absoluta in France by investigating new beneficial insects. Currently, the association of predator/egg parasitoid (Macrolophus pygmaeus and Trichogramma achaeae, respectively) in IPM strategies are quite effective, but expensive. Sixty‐four new potential strains from 19 Trichogramma species originating from different regions of the world (from the collection of Trichogramma at INRA Provence Alpes Côte d'Azur (PACA), France) were studied in this work. A screening study was performed on T. absoluta eggs on isolated tomato leaves (for 24 h at 25 ± 1°C, RH 75 ± 5% and 16 h light : 8 h dark). The proportion of parasitized T. absoluta eggs varied greatly (between 0 and 73%) depending on the different strains used. Levels of parasitism by females, equal to or higher than that of T. achaeae, were observed in 14 of the strains tested among eight species (four from France, four from elsewhere in Europe). The proportion of females that parasitized T. absoluta eggs was significantly different between strains (from 0 to 100%). Experimental results allowed about half of the 64 initial strains to be eliminated before the next steps: tests on a larger scale (mesocosm, and then in the greenhouse and field). 相似文献
79.
Dos Santos JG Blanco MM Do Monte FH Russi M Lanziotti VM Leal LK Cunha GM 《Fitoterapia》2005,76(6):508-513
The hydroalcoholic extract of Equisetum arvense (HAE) tested at the doses of 200 and 400 mg/kg showed a significant activity on the open-field, enhanced the number of falls in the rota-rod reducing the time of permanence in the bar and increased the sleeping time (46% and 74%) in the barbiturate-induced sleeping time. In the pentylenetetrazole-seizure, it increased the first convulsion latency, diminished the severity of convulsions, reduced the percentage of animals which developed convulsion (50% and 25%) and protected animals from death. On the contrary, in the elevated plus maze, the doses 50, 100 and 150 mg/kg did not affect the evaluated parameters. Thus, HAE presented anticonvulsant and sedative effects. Phytochemical analysis detected the presence of tannins, saponins, sterols and flavonoids. 相似文献
80.
Partition coefficients of organophosphorus and organochlorine insecticides were determined in several types of membrane. Insecticide partitioning varied among the membranes under study, depending on temperature, cholesterol content and on the physico-chemical profiles of membrane components and the insecticides themselves. The maximal partitions for DDT, lindane, parathion and malathion in egg phosphatidylcholine bilayers over the temperature range from 10 to 37°C (at which the lipid is in the liquid-crystalline state) were about 260000, 2000, 1000 and 120, respectively. Incorporation of 50 mol% cholesterol in egg phosphatidylcholine bilayers dramatically decreased the partition and almost abolished the temperature effect. First-order phase transitions of dimyristoyl-, dipalmitoyl- and distearoylphosphatidylcholines (DMPC, DPPC and DSPC) were accompanied by a sharp increase in insecticide partition. Furthermore, the insecticides under study were more easily accommodated in bilayers of short-aliphatic-chain lipids, since higher values of partition were obtained in DMPC bilayers. Partition values in native membranes depended considerably on the membrane type and composition and were higher in sarcoplasmic reticulum (SR) and mitochondria than in brain microsomes, myelin and erythrocytes. Identical results were obtained in related liposomes of total extracted lipids, although the absolute partitions showed decreased values. In general, the incorporation of insecticides correlated reasonably with the cholesterol content of the membranes. The order of partitioning of the above insecticides did not run parallel with their toxicity to mammals and, both in model and in native membranes, followed the sequence: DDT ? lindane > parathion > malathion. 相似文献