Book reviews     

Joseph Shalhevet  A. Hadas  Marvin E. Jensen  Amir Kassam 《Irrigation Science》1995,16(1):47-51

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美国花卉业增长渐缓     

Marvin N.Miller  陈晓 《中国花卉园艺》2003,(22):27-31

据估计,2002年美国花卉销售额增长了1.6％。更值得注意的是,2001年和2000年的销售额分别比前一年提高了4.9和11.7个百分点,统计数据来源于美国36个主要花卉生产州的销售额超过10000美元的种植者。 这是《2002年花卉作物摘要》的调查结果,美国农业部国家农业统计中心在2003年4月底发布的,包括2001年花卉生产和销售情况的最新修订数字和2002年的初步统计数字。 担忧、稳定和乐观 据估计,2002年36个州的花卉总销售额为48.79亿美元,比2001年的48.03亿有所提高,可是增长的  相似文献   

Pesticides: overstated dangers     

Marvin PH 《Science (New York, N.Y.)》1967,156(3771):14

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Cordierite-spinel troctolite, a new magnesium-rich lithology from the lunar highlands     

Marvin UB  Carey JW  Lindstrom MM 《Science (New York, N.Y.)》1989,243(4893):925-928

A clast of spinel troctolite containing 8 percent cordierite (Mg(2)Al(4)Si(5)O(18)) has been identified among the constituents of Apollo 15 regolith breccia 15295. The cordierite and associated anorthite, forsteritic olivine, and pleonaste spinel represent a new, Mg-rich lunar highlands lithology that formed by metamorphism of an igneous spinel cumulate. The cordierite-forsterite pair in the assemblage is stable at a maximum pressure of 2.5 kilobars, equivalent to a depth of 50 kilometers, or 10 kilometers above the lunar crust-mantle boundary. The occurrence of the clast indicates that spinel cumulates are a more important constituent of the lower lunar crust than has been recognized. The rarity of cordierite-spinel troctolite among lunar rock samples suggests that it is excavated only by large impact events, such as the one that formed the adjacent Imbrium Basin.  相似文献   

T cell activation by lipopeptide antigens   总被引：2，自引：0，他引：2  

Moody DB  Young DC  Cheng TY  Rosat JP  Roura-Mir C  O'Connor PB  Zajonc DM  Walz A  Miller MJ  Levery SB  Wilson IA  Costello CE  Brenner MB 《Science (New York, N.Y.)》2004,303(5657):527-531

Unlike major histocompatibility proteins, which bind peptides, CD1 proteins display lipid antigens to T cells. Here, we report that CD1a presents a family of previously unknown lipopeptides from Mycobacterium tuberculosis, named didehydroxymycobactins because of their structural relation to mycobactin siderophores. T cell activation was mediated by the alphabeta T cell receptors and was specific for structure of the acyl and peptidic components of these antigens. These studies identify a means of intracellular pathogen detection and identify lipopeptides as a biochemical class of antigens for T cells, which, like conventional peptides, have a potential for marked structural diversity.  相似文献   

Molecular biology. A tail tale for U     

Wickens M  Kwak JE 《Science (New York, N.Y.)》2008,319(5868):1344-1345

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黑谷子新品种丹谷2号选育报告     

张忠福  马文支  温忠琴  徐娅梅 《甘肃农业科技》2015,(11):28-30

黑谷子新品种丹谷2号为野生谷子变异植株中经株系选择选育而成。在甘肃省进行的多点试验中,平均折合产量4 446.53 kg/hm2,较对照品种定西黑谷子增产10.17%。生育期140 d,株高110~130 cm,穗长15~30 cm,千粒重3.3 g。籽粒含粗蛋白87.6 g/kg、胡萝卜素4.7 mg/kg、花青素19.1 mg/kg、钙236.76 mg/kg、铁132.38 mg/kg、锌30.6 mg/kg、硒3.26 mg/kg。适宜甘肃省灌区无霜期140 d以上的区域种植。  相似文献   

Anterior pituitary concentrations of gonadotropins, GnRH-receptors and ovarian characteristics following early weaning in beef cows   总被引：1，自引：0，他引：1  

J R Parfet  C A Marvin  R D Allrich  M A Diekman  G E Moss 《Journal of animal science》1986,62(3):717-722

Endocrine changes in the hypophyseal-ovarian axis associated with early calf removal were investigated in anestrous beef cows. Tissues were collected and analyzed from multiparous beef cows slaughtered at O (n = 8), 36 (n = 8) or 72 h (n = 8) after calf removal during the fifth week after calving. Cows that exhibited estrus; had postmortem signs of a recent ovulation or had serum concentrations of luteinizing hormone (LH) indicative of an ovulatory surge, were excluded from the analysis. Five control cows that were not slaughtered exhibited estrus from 30 to 84 h after calf removal. Seven additional cows were continuously kept with their calves and did not exhibit estrus until 72 +/- 9 d after calving. Serum concentrations of estradiol-17 beta (estradiol) averaged 8.2 +/- 1.7, 7.5 +/- 2.0 and 9.1 +/- 1.5 pg/ml at 0, 36 and 72 h, respectively, but they averaged 22.8 +/- 4.7 pg/ml prior to estrus in control cows. Therefore, observations were assumed to represent events that occur prior to the rise in serum concentrations of estradiol that occurs during proestrus. Volume of fluid from the largest ovarian follicle tended to be greater (P less than .10) at 72 h (1.5 +/- .2 ml) than at 0 h (1.1 +/- .1 ml) or 36 h (1.0 +/- .1 ml). Follicular-fluid concentrations of estradiol, but not progesterone, were positively correlated (P less than .01) with follicular volume. However, numbers of small (less than 100 microliters), medium (100 to 400 microliters) and large follicles (greater than 400 microliters) as based on fluid volume, as well as follicular-fluid concentrations of estradiol and progesterone, did not differ among treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

An animal model for interface tissue formation in cemented hip replacements   总被引：2，自引：0，他引：2  

El-Warrak AO  Olmstead M  Apelt D  Deiss F  Noetzli H  Zlinsky K  Hilbe M  Bertschar-Wolfsberger R  Johnson AL  Auer J  von Rechenberg B 《Veterinary surgery : VS》2004,33(5):495-504

OBJECTIVE: To create a model in sheep for investigation of early changes related to the formation of an interface membrane in hip prosthesis. STUDY DESIGN: Experimental study. ANIMALS: Twenty-four female adult Swiss Alpine sheep. METHODS: Sheep were divided into 2 groups of 12 for unilateral cemented total hip arthroplasty. In Group I, the prosthesis was fixed with retrograde cement gun injection to achieve a complete cement mantle, whereas in Group II a primary cement mantle defect was produced. Groups I and II were further divided into 2 sub-groups with study end points of 2 and 8.5 months after surgery. Radiographs were evaluated postoperatively and at euthanasia for migration of the femoral component and bone resorption. Histologic sections were evaluated semiquantitatively for changes in cell types and numbers, and bone reactions; and quantitatively for size of interface membrane and new bone formation. RESULTS: Radiographically, there tended to be an increase in bone resorption and periosteal bone formation throughout the femoral shaft in Group II compared with Group I, but this was only statistically significant at the region of the femoral neck (R5) at both time periods (P<.05). Semiquantitative histologic evaluation revealed significant increases (P<.05) in cellularity, numbers of fibroblasts, giant cells, macrophages, and mononuclear cells, in Group II primarily at 2 months after surgery. This was also true for interface membrane formation and bone remodeling. Quantitative data showed an increased in the size of the interface membrane and area of bone formation at 8.5 months in Group II. CONCLUSIONS: The cement defect model offered controlled and repeatable production of an interface membrane. The results suggest that a primary cement mantle defect could be a possible trigger for implant instability, eliciting a cascade of biomechanical and molecular events in bone tissue leading to aseptic loosening. CLINICAL RELEVANCE: The results show the effect of defects in the cement mantle in promoting interface membrane formation. Long-term and biochemical studies are required to evaluate the relevance of this interface membrane formation.  相似文献   

Influence of cultivation site on sesquiterpene lactone composition of forage chicory (Cichorium intybus L.)     

Foster JG  Clapham WM  Belesky DP  Labreveux M  Hall MH  Sanderson MA 《Journal of agricultural and food chemistry》2006,54(5):1772-1778

The forage potential of chicory (Cichorium intybus L.) has not been realized in southern West Virginia (WV) because ruminants are reluctant to consume the herbage. Chicory contains bitter sesquiterpene lactones that can adversely impact palatability. This study was undertaken to determine whether sesquiterpene lactone concentrations in chicory grown in southern WV differ from those in chicory grown in central Pennsylvania (PA) where chicory is grazed readily. Herbage was collected in 1997 and 1998 from cultivars Grasslands Puna (Puna), INIA le Lacerta (Lacerta), and Forage Feast established at research sites near State College, PA, and Beckley, WV. The total concentration of sesquiterpene lactones in WV-grown cultivars was 0.58% (dry matter basis) in Puna, 0.59% in Lacerta, and 0.79% in Forage Feast in 1997 and ranged from 1.03 (Lacerta) to 1.52% (Forage Feast) in 1998. In PA-grown cultivars, sesquiterpene lactones represented 0.16 (Puna), 0.18 (Lacerta), and 0.27% (Forage Feast) of the forage dry matter in 1997 and ranged from 0.32 (Lacerta) to 0.55% (Forage Feast) in 1998. Concentrations of lactucin, lactucopicrin, and total sesquiterpene lactones in Forage Feast exceeded those in the other cultivars grown at the same site. The lowest concentrations of lactucopicrin and total sesquiterpene lactones observed among WV-grown cultivars were higher (2-fold or more) than the highest concentrations present in cultivars grown the same year in PA. Mineral analyses of soils from the two cultivation sites indicate that P availability may influence sesquiterpene lactone composition of chicory herbage. Results provide a foundation for future studies of environmental effects on sesquiterpene lactone composition and palatability of chicory herbage.  相似文献