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Inhibition of sperm motility does not affect live-dead separation of bull sperm by glass beads

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Asian Journal of Andrology 2001年第3期3卷 193-198页

作者： robert H.foote Department of Animal Science Cornell University Ithaca NY 14853-4801 USA

Aim: This study was designed to explore factors which influence binding of dead versus live sperm to glass ***: Multiple semen collections from bulls were used to explore selective filtration of bull sperm as influencedby nonlethal inhibition of sperm motility with fluoride, killing of sperm by quick-freezing, alteration of the glass sur-face with silicone, and different intervals of sexual rest between semen collections. Results: A comparison of glassspheres 100, 200 and 390μm in diameter indicated that 200 μm spheres were optimal for selective filtration. Quantita-tive separation of live from dead sperm was demonstrated with a correlation between the percentage of motile sperm andretention of sperm by the filter of r = -0.87 (P l/l NaFl did not alter the proportion ofsperm retained by the filter despite inhibiting sperm motility during filtration, an inhibition which was reversible. Pro-portions of live-dead sperm, based upon eosin staining, were unaffected by fluoride. Coating the glass spheres with sil-icone greatly reduced selective filtration. Dead sperm adherence to glass was reduced and resistance to NaFl inhibitionwas increased by daily ejaculation versus one-week intervals of sexual rest. Conclusion; These studies indicate thatthe adherence of sperm to glass is primarily due to some form of physico-chemical change accompanying death of thesperm cell independent of active sperm motility. This attraction between the sperm plasma membrane and glass is modi-fied by the age of the ejaculated sperm. This information is useful in evaluating different clinical procedures used forsperm separation. (Asian J Androl 2001 Sep; 3: 193-198)

关键词： sperm motility glass spere filters silicone fluorides inhibition

Resazurin reduction and other tests of semen quality and fertility of bulls

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Asian Journal of Andrology 1999年第3期1卷 109-114页

作者： robert H.foote Department of Animal Science Comell University Ithaca NY 14853-4801 USA

Aim: This study was undertaken to compare the reduction in color of two dyes methylene blue (MBRT) and resazurindye (RRT) with other tests of bull semen quality and to examine their relationship to fertility. Methods: One hundredsixty-four ejaculates from 59 bulls were examined, processed, and used for 30 016 inseminations. Results: Bulls usedin artificial insemination have been selected for high semen quality and fertility, and semen from these bulls averaged80.6 % unstained sperm, only 11% had abnormalities, and fertility ranged from 64 %to 76 %. The MBRT and RRTwere run with standardized sperm numbers to prevent sperm concentration from influencing the dye reduction time. Ashort RRT was correlated with higher fertility ( r = -0.26) but MBRT was not correlated ( r = -0.05, P >0.0,5).The correlations were low, but axe typical and reflect the statistical effect of the large binomial variance associated withpregnancy or nonpregnancy being coded as 1 or O. Conclusion: The fact that the RRT was significantly correlated withfertility when sperm numbers were standardized, and published reports that resazurin is useful for monitoring other semencharacteristics, indicate that this dye may provide valuable information not given by other simple laboratory tests. (AsianJ Androl 1999 Sep; 1: 109 - 114 )

关键词： fertility semen spermatozoa cattle resazurin reduction

Evaluating information-seeking approaches to metacognition

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Current Zoology 2011年第4期57卷 531-542页

作者： Jonathon D. CRYSTAl Allison l. foote Department of Psychological and Brain Sciences Indiana University Bloomington IN 47405 USA Department of Psychology University of Georgia Athens GA 30602 USA

Metacognition has been divided into information monitoring and control processes. Monitoring involves knowing that you know or do not know some information without taking corrective action. Control involves taking corrective action based on the knowledge that you know or do not know some information. In comparative metacognition, considerable attention has been paid toward critically assessing putative evidence for information monitoring in non-human animals. However, less attention has been paid toward critically evaluating evidence for control processes in animals. We briefly review a critique of information-monitoring in animals. Next, we apply these concepts to a number of studies that focus on information seeking in animals. The main type of evidence for control processes in animals come from tube tipping experiments. Before having the opportunity to search for the bait in these experiments, the subject sometimes observes opaque tubes being baited but is sometimes prevented from seeing the baiting. The observations that the subjects look more if baiting was not seen and are more accurate if baiting was seen have been taken as evidence for metacognition in information-seeking experiments. We propose simple alternative hypotheses that are sufficient to explain putative evidence for information seeking in animals without positing metacognition. The alternative explanation focuses on two relatively simple principles： First, an animal has a default ＂look before you go＂ response which supersedes random searches in space. Second, spatially guided behavior follows a default rule of ＂go where something good is.＂ These principles can explain the results of tube tipping experiments without proposing metacognition [Current Zoology 57 （4）： 531-542, 2011].

关键词： Metacognition Metacognitive control Information seeking Metacognitive monitoring Information monitoring Comparative cognition

SO(n)-Invariant Special lagrangian Submanifolds of C^(n+1) with Fixed loci

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Chinese Annals of Mathematics,Series B 2006年第1期27卷 95-112页

作者： robert l. BRYANT Dedicated to the memory of Shiing-Shen Chern

let SO（n） act in the standard way on C^n and extend this action in the usual way to C^n＋l = C＋ C^n. It is shown that a nonsingular special lagrangian submanifold l→∪ C^n＋l that is invariant under this SO（n）-action intersects the fixed C→∪ C^n＋1 in a nonsingular real-analytic arc A （which may be empty）. If n 〉 2, then A has no compact component. Conversely, an embedded, noncompact nonsingular real-analytic arc A→∪ C lies in an embedded nonsingular special lagrangian submanifold that is SO（n）-invariant. The same existence result holds for compact A if n =2. nonsingular SO（n）-invariant special lagrangian nonsingular SO（n）-invariant special lagrangian extensions in some open neighborhood of A. If A is connected, there exist n distinct extensions of A such that any embedded extension of A agrees with one of these n The method employed is an analysis of a singular nonlinear PDE and ultimately calls on the work of Gerard and Tahara to prove the existence of the extension.

关键词： Calibrations Special lagrangian submanifolds

Boundary element method (BEM) applied to the rough surface contact vs. BEM in computational mechanics

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Friction 2019年第4期7卷 359-371页

作者： Yang XU robert l.JACKSON Mechanical Engineering Department Auburn University

In the numerical study of rough surfaces in contact problem, the flexible body beneath the roughness is commonly assumed as a half-space or a half-plane. The surface displacement on the boundary, the displacement components and state of stress inside the half-space can be determined through the convolution of the traction and the corresponding influence function in a closed-form. The influence function is often represented by the Boussinesq-Cerruti solution and the Flamant solution for three-dimensional elasticity and plane strain/stress, respectively. In this study, we rigorously show that any numerical model using the above mentioned half-space solution is a special form of the boundary element method(BEM). The boundary integral equations(BIEs) in the BEM is simplified to the Flamant solution when the domain is strictly a half-plane for the plane strain/stress condition. Similarly, the BIE is degraded to the Boussinesq-Cerruti solution if the domain is strictly a half-space. Therefore, the numerical models utilizing these closed-form influence functions are the special BEM where the domain is a half-space(or a half-plane). This analytical work sheds some light on how to accurately simulate the non-half-space contact problem using the BEM.

关键词： boundary element method rough surface contact half-space half-plane Flamant solution Boussinesq-Cerruti solution

抑制精子活力不影响玻璃珠分离牛死、活精子的能力

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生殖与避孕 2002年第1期22卷 63-64页

作者： robert H.foote Department

研究哪些能影响玻璃珠滤器结合死、活牛精子的因素。方法:多次采取精液,用玻璃珠选择性过滤牛精子,研究下述因素的影响:以氟化物非致死性地抑制精子活力、以快速冷冻法杀死精子、以硅树脂改变玻璃珠表面、以不同的间隔时间采集精子。结... 详细信息

研究哪些能影响玻璃珠滤器结合死、活牛精子的因素。方法:多次采取精液,用玻璃珠选择性过滤牛精子,研究下述因素的影响:以氟化物非致死性地抑制精子活力、以快速冷冻法杀死精子、以硅树脂改变玻璃珠表面、以不同的间隔时间采集精子。结果:使用不同直径玻璃珠（100、200、300μm）的比较研究表明,直径200μm者最适于选择性过滤。过滤死、活精子的定量研究表明,活精子百分率与过滤器保留精子的相关系数为r=-0.87（Pl/l或更低时不影响过滤器保留精子的比例。曙红染色表明,死、活精子的比例不受氟化物的影响。以硅树脂包裹玻璃珠后显著降低其选择性过滤能力。与一周的采样间隔期相比,每日采样减少了死精子对玻璃珠的吸附,也增强了对氟化钠抑制的耐受力。结论:精子对玻璃珠的吸附基本上与精子死亡时伴随的生理-化学变化相关联,而与精子活力无关。精子质膜与玻璃珠间的此项吸附力受射精间隔时间所左右。这一信息对于正确评价各种精子分离方法是有价值的。

关键词：精子活力玻璃珠滤器动物实验精子分离

Assessment of portable FTIR and Raman spectroscopy for the detection of 2,3-dimethyl-2,3-dinitrobutane(DMDNB)in plastic explosives

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Defence Technology（防务技术） 2024年第4期34卷 11-18页

作者： Jacky Cailes robert Dunsmore Kathryn l.linge ChemCentre PO Box 1250PerthAustralia

The Marplex Convention was established to prevent the manufacture of unmarked plastic explosives and stipulates that a volatile detection agent must be added at the time of ***,to-date,laboratory testing remains the internationally accepted practice for identifying and quantifying the taggants stipulated in the *** this project,portable FTIR and Raman instruments were tested for their ability to detect 2,3-dimethyl-2,3-dinitrobutane(DMDNB),the chemical marker incorporated in plastic explosives that are manufactured within *** both FTIR and Raman instruments detected solid DMDNB(98%purity),field analysis of plastic explosives at an Australian Defence establishment showed that both FTIR and Raman spectra were matched the relevant explosive(RDX or PETN),rather than the DMDNB *** all three plastic explosives tested,the concentration of DMDNB was measured by SPME-GC-MS to be between 1.8 and 2%,greater than the minimum 1%concentration stipulated by the Marplex *** testing with a plastic explosive analogue confirmed that the minor absorption peaks that would characterize low concentrations of DMDNB were masked by absorption bands from other compounds within the ***,while both FTIR and Raman spectroscopy are suitable for detection of plastic explosives,neither rely on the presence of DMDNB for *** is likely that similar results would be found for other taggants stipulated by the Marplex Convention,given they are also present in concentrations less than 1%.

关键词： Explosive ICAO taggants 2,3-Dimethyl-2,3-dinitrobutane(DMDNB) Fourier transform infrared(FTIR) Raman

The influence of various grease compositions and silver nanoparticle additives on electrically induced rolling-element bearing damage

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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND robert l.JACKSON German MIllS Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

Erratum to Genetic and molecular changes in ovarian cancer

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Cancer Biology & Medicine 2017年第2期14卷 196-201页

作者： robert l Hollis Charlie Gourley Edinburgh Cancer Research UK Centre MRC Institute of Genetics and Molecular Medicine University of Edinburgh Edinburgh EH4 2XR UK

In the published article~, some errors appeared on page 238, Figure 1, and reference list. The editors and the authors apologize for the errors and for any confusion they may have caused. On page238, the sentence of ＂affecting 20% and 17.5% of cases＂ should be changed to ＂and that inactivation of these genes occurs in 17.5% and 20% of cases＂.

关键词：卵巢癌分子遗传勘误基因失活