桑苗圃和桑园的化学除草     

黄健明  仇广泰  薛彦明 《蚕桑通报》2001,32(1):27-28

用氟乐灵和精稳杀得或高效盖草能进行桑苗圃除草，用草甘磷和乙草胺混合进行桑园除草，可有效地防除杂草。  相似文献   

母牛一胎双犊技术的研究     

张居农  蒋学国  许斌  郭成宽  仇其山  李强  牛志宏  王安江  王凤娇  张建军  张选珠 《乳业科学与技术》2005,27(3):137-138

选择9头母牛先行人工授精、7天后再移植冷冻胚胎以生产双犊。试验结果表明,母牛产双犊达44.44%(P<0.01)。提示:采用A(I人工授精)+ET(胚胎移植)是提高母牛双犊率的有效技术措施之一。  相似文献   

国内外农村住宅建设比较          下载免费PDF全文

丑洋  郭琴 《农业工程》2018,8(1):53-56

农村住宅建设是新农村建设的重要组成部分，在农村经济、社会、生态和文化发展等方面发挥着重要作用。从生态住宅建设角度出发，借鉴国外农村住宅建设经验，依据我国农村住宅建设现状，通过国内外农村住宅建设对比分析，总结国外农村生态住宅建设对我国的启示。   相似文献   

秈粳稻杂交育种研究   总被引：5，自引：0，他引：5  

朱立宏  周毓珍  陶世昌 《作物学报》1964,3(1):69-86

作者研究了秈粳杂种的生育特性及结实性等经济性状的遗传变异,认为以出穗期为主要指标进行选择,结合其他性状的变异动态,逐步确立优良系统,有助于提高选择的效率,和建立较为合理的杂交育种程序与方法。  相似文献   

Effects of Culture Area,Stocking Density,and Shrimp and Fish Polyculture on the Cost Efficiency of Hard Clam,Meretrix meretrix,Culture: A Case Study of Hard Clam Farms in Yunlin,Taiwan          下载免费PDF全文

Jung‐Fu Huang  Ming‐Tao Chou  Jie‐Min Lee  Yung‐Hsin Cheng 《Journal of the World Aquaculture Society》2016,47(4):481-495

Using the hard clam farms in Yunlin, Taiwan as examples, this study analyzes the effects of culture area, stocking density, and shrimp and fish polyculture on the cost efficiency (CE) of hard clam farming. A data envelopment analysis (DEA) is used to estimate the farms' technical efficiency (TE), allocative efficiency (AE), and CE values. The findings show that the mean TE, AE, and CE values of hard clam farms are 0.74, 0.57, and 0.43, respectively. The TE value is higher than the AE value, which indicates that cost inefficiency is mainly attributable to poor AE. Tobit regression results suggest that there are positive relationships between CE and both culture area and operator experience. Hard clam stocking density and age of the operators have negative effects on CE. Hard clam culture areas larger than 2 ha and a stocking density of 1.1–1.2 million hard clams per hectare have higher CEs than smaller culture areas and smaller or larger stocking densities. The use of sand shrimp, white shrimp, kuruma shrimp, and grass shrimp for polyculture and the use of milkfish and silver sea bream for polyculture are both associated with high CEs.  相似文献   

Towards an integrative biology research: a case study on adaptive and evolutionary trends of Miscanthus populations in Taiwan     

Chang-Hung Chou  Tseng-Yu Chiang  Yu-Chung Chiang 《Weed Biology and Management》2001,1(2):81-88

A program of research named Towards an Integrative Biology (TAIB) has recently been promoted by the International Union of Biological Sciences, involving multidisciplinary and interdisciplinary research. Studies of Miscanthus plants which emphasized the TAIB theme were undertaken. Miscanthus species are the most widely distributed and dominant species in Taiwan, growing everywhere from the coastal to mountainous areas, and from agricultural to polluted land. Particularly, the grasses grow well in habitats under environmental stresses. Physiological and genetic adaptations are fundamental mechanisms for these grasses' survival in stressful environments. Findings based on field measurements and laboratory analyses were able to elucidate some of the mechanisms of grasses adapted to stressful environments. Adaptive radiation occurred when most niches were open during the postglacial periods. Particularly, population discontinuity of the grasses was found on the Orchid and Green islets of Taiwan. Likewise, Miscanthus sinensis var. glaber and var. formosanus occupied lands from low to middle elevations of Taiwan, while Miscanthus transmorrisonensis appeared in the highlands above 2400 m. Phylogenetically, Miscanthus has evolved into various ecotypes, varieties and species in Taiwan as well as in other parts of Asia. The grass then evolved into Miscanthus floridulus , M. sinensis var. formosanus , Miscanthus flavidus , then to M. transmorrisonensis . Furthermore, the phylogeny of the Miscanthus sinensis complex of Taiwan was reconstructed by cladistic analysis on nucleotide sequences of nuclear ribosomal DNA internal transcribed spacers (nrDNA ITS) region and atpB - rbc L non-coding spacer of the chloroplast DNA. Rooted at M . floridulus the monophyly of M . sineneis was significantly supported by molecular evidence. The origin of this complex could be dated to the last glacial withdrawal about 20 000 years ago.  相似文献   

Perspectives of disease threat in large-scale Pinus radiata monoculture - the New Zealand experience     

C. K. S. Chou 《Forest Pathology》1991,21(2):71-81

Large scale P. radiata monoculture has been in existence in New Zealand for over 60 years. During this time a number of damaging diseases (e. g. Sirex-Amylostereum, Dothistroma, Armillaria, Cydaneusma needle cast. Sphaeropsis die-back etc.) have occurred but the impact was by no means devastating as these diseases are either controllable or in some the losses were deemed acceptable. As a large proportion of the biomass produced before age 10–12 is waste-thinned, the acceptable level of disease loss is thereby very high. The practice of clear felling and short rotation reduces some of the disease risks common in other forest systems. Outlook for future disease threat is discussed with respect to current trends toward clonal forestry and the possible arrival of additional exotic pathogens.  相似文献   

Baicalein induction of hydroxyl radical formation via 12-lipoxygenase in human platelets: an ESR study     

Chou DS  Lee JJ  Hsiao G  Hsieh CY  Tsai YJ  Chen TF  Sheu JR 《Journal of agricultural and food chemistry》2007,55(3):649-655

The pro-oxidant activities of baicalein, morin, myricetin, quercetin, and rutin were examined in various cell-containing systems including human platelets, rat vascular smooth muscle cells, human umbilical vein endothelial cells (HUVECs), human THP-1 cells, and fibroblast cells. Electron spin resonance (ESR) results showed that only baicalein generated hydroxyl radicals in a resting human platelet suspension, whereas the other flavonoids showed no effects on any of the resting cell systems. A low concentration of arachidonic acid (AA) increased the intensity of hydroxyl radicals, but a high concentration inhibited it. Collagen and thrombin, platelet aggregatory agents that can cause the release of AA by platelets, enhanced baicalein-induced hydroxyl radical formation, whereas ADP and U44619 showed no significant effects. Quinacrine and 5,8,11,14-eicosatetraenoic trifluoromethyl ketone, both PLA2 inhibitors, significantly attenuated baicalein-induced hydroxyl radical formation. These results suggest that baicalein-induced hydroxyl radical formation is associated with AA metabolite enzymes in human platelets. The formation of hydroxyl radicals was significantly inhibited by lipoxygenase inhibitors including nordihydroguaiaretic acid, (-)-epicatechin, (-)-epicatechin gallate, and hinokitiol, but was not affected by desferroxamine or the heme protein inhibitors KCN and NaN3. On the other hand, semiquinone free radicals were generated when baicalein was incubated with horseradish peroxidase/H2O2 or platelets/AA. The semiquinone radicals formed in the platelets/AA system could be extensively inhibited by desferroxamine, diethylenetriaminepentaacetic acid, KCN, and NaN3, indicating that prostaglandin H synthase (PGHS)-peroxidase may be involved. The results of this study led to the proposal that baicalein induces hydroxyl radical formation via 12-lipoxygenase and induces semiquinone radical formation via PGHS-peroxidase in human platelets.  相似文献   

Effect of a sand substrate on the growth and survival of hatchlings of the softshell turtle, Trionyx sinensis Wiegmann     

B.L. Choo  L.M. Chou 《Aquaculture (Amsterdam, Netherlands)》1984,40(4):325-331

Softshell turtle (Trionyx sinensis Wiegmann) hatchlings were reared at 28 ± 2°C in the laboratory to test the effect of the presence of a sand substrate. The growth and survival of the hatchlings were monitored for a period of 14 weeks. The presence of the sand substrte significantly enhanced the growth of the hatchlings. Survival of the hatchlings, however, was independent of the presence of the sand substrate.  相似文献   

Dietary Fucoxanthin Increases Metabolic Rate and Upregulated mRNA Expressions of the PGC-1alpha Network,Mitochondrial Biogenesis and Fusion Genes in White Adipose Tissues of Mice     

Meng-Ting Wu  Hong-Nong Chou  Ching-jang Huang 《Marine drugs》2014,12(2):964-982

The mechanism for how fucoxanthin (FX) suppressed adipose accumulation is unclear. We aim to investigate the effects of FX on metabolic rate and expressions of genes related to thermogenesis, mitochondria biogenesis and homeostasis. Using a 2 × 2 factorial design, four groups of mice were respectively fed a high sucrose (50% sucrose) or a high-fat diet (23% butter + 7% soybean oil) supplemented with or without 0.2% FX. FX significantly increased oxygen consumption and carbon dioxide production and reduced white adipose tissue (WAT) mass. The mRNA expressions of peroxisome proliferator-activated receptor (PPAR) γ coactivator-1α (PGC-1α), cell death-inducing DFFA-like effecter a (CIDEA), PPARα, PPARγ, estrogen-related receptor α (ERRα), β3-adrenergic receptor (β3-AR) and deiodinase 2 (Dio2) were significantly upregulated in inguinal WAT (iWAT) and epididymal WAT (eWAT) by FX. Mitochondrial biogenic genes, nuclear respiratory factor 1 (NRF1) and NRF2, were increased in eWAT by FX. Noticeably, FX upregulated genes of mitochondrial fusion, mitofusin 1 (Mfn1), Mfn2 and optic atrophy 1 (OPA1), but not mitochondrial fission, Fission 1, in both iWAT and eWAT. In conclusion, dietary FX enhanced the metabolic rate and lowered adipose mass irrespective of the diet. These were associated with upregulated genes of the PGC-1α network and mitochondrial fusion in eWAT and iWAT.  相似文献