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161.
赵善欢 《西北农林科技大学学报(自然科学版)》1995,23(3):21-24
根据作者几年来的实地调查观察并参考了大量的国内外最新文献,较系统地阐述了小菜蛾(Pluiellaxylostella)的生物学特性和抗药性现状,全面提出了小菜蛾综合治理策略。 相似文献
162.
Neuronal activity in narcolepsy: identification of cataplexy-related cells in the medial medulla 总被引:7,自引:0,他引:7
J M Siegel R Nienhuis H M Fahringer R Paul P Shiromani W C Dement E Mignot C Chiu 《Science (New York, N.Y.)》1991,252(5010):1315-1318
Narcolepsy is a neurological disorder characterized by sleepiness and episodes of cataplexy. Cataplexy is an abrupt loss of muscle tone, most often triggered by sudden, strong emotions. A subset of cells in the medial medulla of the narcoleptic dog discharged at high rates only in cataplexy and rapid eye movement (REM) sleep. These cells were noncholinergic and were localized to ventromedial and caudal portions of the nucleus magnocellularis. The localization and discharge pattern of these cells indicate that cataplexy results from a triggering in waking of the neurons responsible for the suppression of muscle tone in REM sleep. However, most medullary cells were inactive during cataplexy but were active during REM sleep. These data demonstrate that cataplexy is a distinct behavioral state, differing from other sleep and waking states in its pattern of brainstem neuronal activity. 相似文献
163.
Pappu R Cheng AM Li B Gong Q Chiu C Griffin N White M Sleckman BP Chan AC 《Science (New York, N.Y.)》1999,286(5446):1949-1954
Linker proteins function as molecular scaffolds to localize enzymes with substrates. In B cells, B cell linker protein (BLNK) links the B cell receptor (BCR)-activated Syk kinase to the phosphoinositide and mitogen-activated kinase pathways. To examine the in vivo role of BLNK, mice deficient in BLNK were generated. B cell development in BLNK-/- mice was blocked at the transition from B220+CD43+ progenitor B to B220+CD43- precursor B cells. Only a small percentage of immunoglobulin M++ (IgM++), but not mature IgMloIgDhi, B cells were detected in the periphery. Hence, BLNK is an essential component of BCR signaling pathways and is required to promote B cell development. 相似文献
164.
Zhang SY Jouanguy E Ugolini S Smahi A Elain G Romero P Segal D Sancho-Shimizu V Lorenzo L Puel A Picard C Chapgier A Plancoulaine S Titeux M Cognet C von Bernuth H Ku CL Casrouge A Zhang XX Barreiro L Leonard J Hamilton C Lebon P Héron B Vallée L Quintana-Murci L Hovnanian A Rozenberg F Vivier E Geissmann F Tardieu M Abel L Casanova JL 《Science (New York, N.Y.)》2007,317(5844):1522-1527
Some Toll and Toll-like receptors (TLRs) provide immunity to experimental infections in animal models, but their contribution to host defense in natural ecosystems is unknown. We report a dominant-negative TLR3 allele in otherwise healthy children with herpes simplex virus 1 (HSV-1) encephalitis. TLR3 is expressed in the central nervous system (CNS), where it is required to control HSV-1, which spreads from the epithelium to the CNS via cranial nerves. TLR3 is also expressed in epithelial and dendritic cells, which apparently use TLR3-independent pathways to prevent further dissemination of HSV-1 and to provide resistance to other pathogens in TLR3-deficient patients. Human TLR3 appears to be redundant in host defense to most microbes but is vital for natural immunity to HSV-1 in the CNS, which suggests that neurotropic viruses have contributed to the evolutionary maintenance of TLR3. 相似文献
165.
166.
Lin Yu-Te Whitman William B. Coleman David C. Chen Tsai-Huei Chiu Chih-Yu 《Biology and Fertility of Soils》2014,50(5):809-814
Biology and Fertility of Soils - Coastal sand dunes are a hostile environment for forests. Little is known about the composition and diversity of the bacterial community in forest soils established... 相似文献
167.
Ching-Yu Huang Shih-Hao Jien Tsai-Huei Chen Guanglong Tian Chih-Yu Chiu 《Journal of Soils and Sediments》2014,14(6):1061-1070
Purpose
Moso bamboo (Phyllostachys edulis), an important economic crop, is distributed from low- to medium-elevation mountains in Taiwan. Bamboo is a fast-growing herbaceous species with an extensive rhizome structure. With the hypothesis that the characteristics of soil organic matter and microbes might change after long-term bamboo plantation, we investigated different fractions of organic C and N as well as soil microbial biomass and activities in five moso bamboo plantations along an elevation gradient in Central Taiwan.Materials and methods
Five soil samples (top 10 cm of soil) were collected from each bamboo plantation (600, 800, 1,000, 1,200, and 1,400 m above sea level (asl)) in January 2011. Soil was processed and analyzed for soil total C and N contents, biologically available C, potentially mineralizable N, soil microbial biomass and soil respiration (CO2). Two extraction methods (2 M KCl and hot-water extraction) were used to estimate soil soluble organic C and N (SbOC and SbON) and soil inorganic N (NH4 + and NO3 ?) concentrations to evaluate the relationship with soil organic matter and microbe characteristics in bamboo plantations.Results and discussion
Soil total C and N contents as well as soil microbial biomass and soil respiration (CO2) of the bamboo plantations increased along the elevation gradient. Temperature changes along elevation contributed to such variations observed among the selected bamboo plantations. The SbON in hot-water extracts was highest in the 1,200-m plantation, then in the 1,400-m plantation, and lowest in the low-elevation plantations (600, 800, and 1,000 m). However, SbON in 2 M KCl extracts did not differ by elevation. The SbON was strongly correlated with soil total N in both 2 M KCl and hot-water extracts, but only SbON in hot-water extracts was strongly correlated with microbial biomass N and potentially mineralizable N. SbOC was strongly correlated with soil total C content, microbial biomass C, and biologically available C in both 2 M KCl and hot-water extracts.Conclusions
Soil total C and N, SbOC and SbON, and microbial biomass characteristics increased in the moso bamboo plantations with increasing elevation. No altitudinal difference in specific soil respiration (CO2) rate suggested that the enhanced potentially mineralizable N and soil respiration (CO2) in the high-elevation plantations were associated with increased microbial biomass rather than microbial activities. 相似文献168.
Placic (Bsm) and spodic (Bhs) horizons are common in subalpine or alpine forest soils in Taiwan. Bsm horizons are found more usually in finer textured soils than those with Bhs horizons. To understand the different formation processes in Bsm and Bhs horizons in a humid subtropical ecosystem, we identified micro‐morphological features by using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and electron probe micro‐analysis (EPMA), and determined the physiochemical properties by chemical extractions and clay mineralogy. The study included four pedons with well‐developed Bsm horizons from our previous study and four with well‐developed Bhs horizons at other sites. Both sites were in subtropical mountain forests with similar climate, topography and general geology but over regoliths with distinctly different textures. Micro‐morphology revealed a vughy (small cavities lined with in‐washed materials) microstructure in Bsm horizons but a granular structure with bridge microstructures between coarse grains in Bhs horizons. Chemical analysis revealed more free pedogenic iron (Fed) and aluminium (Ald) in Bsm than in Bhs horizons, but more organically complexed Al (Alp) in Bhs horizons. Energy dispersive spectrometry revealed predominant Fe, oxygen (O) and carbon (C) in the matrix of the Bsm horizons, whereas Al, silicon (Si) and C were the major elements of interstitial materials in Bhs horizons. Polarizing microscopy and EPMA spectra confirmed the illuvial nature of organic Al complexes in Bhs horizons. The transformation of clay minerals showed more intense podzolization in Bhs horizons than in Bsm horizons. The different formation mechanisms in Bsm and Bhs horizons result from contrasting texture; redox processes are predominant in Bsm horizons because of the clayey texture whereas podzolization is predominant in sandy Bhs horizons. 相似文献
169.
Weihsueh A. Chiu Frédéric Y. Bois 《Journal of Agricultural, Biological & Environmental Statistics》2007,12(3):346-363
Standard statistical models for analyzing inter-individual variability in clinical pharmacokinetics (nonlinear mixed effects;
hierarchical Bayesian) require individual data. However, for environmental or occupational toxicants only aggregated data
are usually available, so toxicokinetic analyses typically ignore population variability. We propose a hierarchical Bayesian
approach to estimate inter-individual variability from the observed mean and variance at each time point, using a bivariate
normal (or lognormal) approximation to their joint likelihood. Through analysis of both simulated data and real toxicokinetic
data from 1,3-butadiene exposures, we conclude that given information on the form of the individual-level model, useful information
on inter-individual variability may be obtainable from aggregated data, but that additional sensitivity and identifiability
checks are recommended. 相似文献
170.
Chih-Ming Chiu Song-Yung Wang Cheng-Jung Lin Te-Hsin Yang Ming-Chun Jane 《Journal of Wood Science》2006,52(1):9-14
The fractometer is a device that breaks a radial increment core along the fiber for the measurement of crushing strength,
which is a direct wood quality indicator for structural lumber. In this study, the crushing strength of Taiwania (Taiwania cryptomerioides Hay) trees using the fractometer was investigated and the data were used to determine the position of demarcation between
juvenile and mature wood. Segmented regression and variance component analysis were used to estimate the demarcation position.
With increasing cambium age, the core wood improves the crushing strength in the outer wood area. Within-tree variations in
wood properties were greater than between-tree variations. In this experiment, the position of demarcation between juvenile
and mature wood occurred at an approximate distance of 10.8cm to 13.2cm from the pith at about 18–20 years of cambium age. 相似文献