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1.
RobertGWIAZDA 《动物学报》2005,51(2):215-221
与水库水位低、繁殖群已经形成的2000-2001年相比, 苍鹭(Ardea cinerea) 的种群数量在水位正常、尚未繁殖的1990-1991年相对较低。该种鸟类在水库的3个地点取食。1990-1991年的8 月或9 月, 其数量达到最高值, 并有较高比例的个体出现在水库深水区的平坦的岸边。2000-2001 年的数量高峰在6 月份, 有大量的觅食个体出现在回水区, 在那里形成了新的生境(水塘、浅水区和沙洲)。苍鹭迁离或飞往繁殖地的活动在早晨或中午之前强于中午或下午。在其食物中共鉴别出17种鱼类, 其中数量最多的是圆鳍雅罗鱼和拟鲤。在苍鹭食物中, 游动性鱼类比例较高(2001年占32%, 2003年占25%), 表明它是在河流和水库之间的生态交错区取食的。所捕食鱼类的全长为4 cm到33 cm, 生物量在2-406 g之间。在2001 年和2003 年苍鹭食物中鱼类的全长未见明显差异。  相似文献   
2.
Approximately 1460 species of spiders have been reported from Canada, 3% of the global fauna. This study provides a DNA barcode reference library for 1018 of these species based upon the analysis of more than 30 000 specimens. The sequence results show a clear barcode gap in most cases with a mean intraspecific divergence of 0.78% vs. a minimum nearest‐neighbour (NN) distance averaging 7.85%. The sequences were assigned to 1359 Barcode index numbers (BINs) with 1344 of these BINs composed of specimens belonging to a single currently recognized species. There was a perfect correspondence between BIN membership and a known species in 795 cases, while another 197 species were assigned to two or more BINs (556 in total). A few other species (26) were involved in BIN merges or in a combination of merges and splits. There was only a weak relationship between the number of specimens analysed for a species and its BIN count. However, three species were clear outliers with their specimens being placed in 11–22 BINs. Although all BIN splits need further study to clarify the taxonomic status of the entities involved, DNA barcodes discriminated 98% of the 1018 species. The present survey conservatively revealed 16 species new to science, 52 species new to Canada and major range extensions for 426 species. However, if most BIN splits detected in this study reflect cryptic taxa, the true species count for Canadian spiders could be 30–50% higher than currently recognized.  相似文献   
3.
Abstract The results of Most Probable Number determinations applying low and high concentrations of nitrite reveal the presence of at least two different communities of potential nitrite-oxidizing bacteria in a number of soil types. The effect of plant roots on these two communities was studied in pot experiments with soil from natural grassland in the presence or absence of either Festuca rubra or Plantago lanceolata . Both plant species are dominant on the grassland soil used in this study. Plant roots had a stimulating effect on the numbers of nitrite-oxidizing bacteria determined with 0.05 mM nitrite in the enumeration medium as well as on the potential nitrite-oxidizing activity. On the other hand, plants roots, especially in younger plants, repressed the numbers of nitrite-oxidizing bacteria enumerated with 5.0 mM nitrite in the counting medium. Pure culture studies with organotrophically grown Nitrobacter species clearly showed that this type of potential nitrite-oxidizing bacteria could not have been responsible for the relatively high Most Probable Numbers observed in the root zones when applying 0.05 mM nitrite in the enumeration medium.  相似文献   
4.
Aggregation of biotherapeutics has the potential to induce an immunogenic response. Here, we show that aggregated therapeutic antibodies, previously generated and determined to contain a variety of attributes (Joubert, M. K., Luo, Q., Nashed-Samuel, Y., Wypych, J., and Narhi, L. O. (2011) J. Biol. Chem. 286, 25118-25133), can enhance the in vitro innate immune response of a population of naive human peripheral blood mononuclear cells. This response depended on the aggregate type, inherent immunogenicity of the monomer, and donor responsiveness, and required a high number of particles, well above that detected in marketed drug products, at least in this in vitro system. We propose a cytokine signature as a potential biomarker of the in vitro peripheral blood mononuclear cell response to aggregates. The cytokines include IL-1β, IL-6, IL-10, MCP-1, MIP-1α, MIP-1β, MMP-2, and TNF-α. IL-6 and IL-10 might have an immunosuppressive effect on the long term immune response. Aggregates made by stirring induced the highest response compared with aggregates made by other methods. Particle size in the 2-10 μm range and the retention of some folded structure were associated with an increased response. The mechanism of aggregate activation at the innate phase was found to occur through specific cell surface receptors (the toll-like receptors TLR-2 and TLR-4, FcγRs, and the complement system). The innate signal was shown to progress to an adaptive T-cell response characterized by T-cell proliferation and secretion of T-cell cytokines. Investigating the ability of aggregates to induce cytokine signatures as biomarkers of immune responses is essential for determining their risk of immunogenicity.  相似文献   
5.
目的:将传统的外周血单个核细胞分离计数方法加以改进,并探讨2型糖尿病(DM)患者外周血单个核细胞数量与疾病的相关性。方法:密度梯度离心分离30例健康体检者单个核细胞,不同染色稀释液重悬细胞,充入改良牛鲍计数板连续计数5天,计算批内、批间变异;采用上述方法分离2型DM患者抗凝全血29例,计算单个核细胞数量;采用全自动生化分析仪检测对照组和2型DM组患者血脂。结果:两组的单个核细胞经3种前处理染液稀释重悬细胞后,计数结果间无统计学差异(P0.05);2型DM组与健康对照组比较,外周血单个核细胞计数绝对值无显著性差异(P0.05),血清TG、TC、LDL水平明显升高,差别具有统计学意义(P0.05),而其他指标结果间比较无差异。在对照组中,单个核细胞计数结果与白细胞呈正相关(r=0.611,P0.05),与血清TC、LDL水平呈负相关(r1=-0.550,r2=-0.605,P0.05)。而T2DM组,单个核细胞计数结果仅与LDL水平呈负相关(r=-0.104,P0.05)。结论:外周血单个核细胞数与2型糖尿病无明显相关性。  相似文献   
6.
A variety of approaches are available for identifying the location and effect of QTL in segregating populations using molecular markers. However, these have problems in distinguishing two linked QTL, particularly in relation to the size of the test statistic when many independent tests are performed. An empirical method for obtaining the distribution of the test statistic for specific datasets is described, and its power for demonstrating the inadequacy of a single-QTL model is explored through computer simulation. The method is an extension of the previously described technique of marker regression, and it is applied here to demonstrate two situations in which it may be useful. Firstly, we examine the power of the technique to distinguish two, linked QTL from one and compare this ability with that of two contemporary methods, Mapmaker/QTL and regression mapping. Secondly, we show how to combine information from two, or more, populations that may be segregating for different marker loci in a given linkage group. This is illustrated for two populations having in common just two linked marker loci although the sharing of loci is not a pre-requisite. Empirical tests are used to determine whether the same or different QTL are segregating and, if they are the same QTL, whether they are the same alleles. Evidence is discussed which suggests that the upper limit to the number of QTL that can be located for any single quantitative trait in a segregating populations is 12.  相似文献   
7.
四川梅花鹿的分布、数量及栖息环境的调查   总被引:6,自引:2,他引:4  
1992年 7月至 1 999年 8月野外调查发现 ,四川梅花鹿现残存于青藏高原东部边缘山地、岷山山系北段 3块相互完全隔离的区域。铁布分布区 (E1 0 2°46′~ 1 0 3°1 4′、 N33°58′~ 34°1 6′)属四川省若尔盖县铁布自然保护区和占哇乡、降扎乡 ,甘肃省迭部县益哇乡、电尕乡 ,面积 860 km2 ,有鹿 630~ 650只 ;巴西分布区 (E1 0 3°0 8′~ 1 0 3°35′、 N33°33′~ 33°46′)属若尔盖县巴西乡、求吉乡、阿西茸乡、包座乡和九寨沟县的大录乡 ,面积 60 3km2 ,有鹿 1 30~ 1 50只 ;白河分布区 (E1 0 3°59′~ 1 0 4°1 0′、N33°0 5′~ 33°2 0′)属四川省九寨沟县白河自然保护区和农康乡、白河乡、罗依乡、马家乡 ,面积 390 km2 ,有鹿 30~ 45只。高原与高山峡谷的过渡地貌、山地温带气候、森林与灌丛草甸相互镶合的植被 ,加之地域偏僻、人烟稀少 ,当地藏族群众视其为神鹿 ,使上述 3个区域成为四川梅花鹿最后的避难所。  相似文献   
8.
Björn Bornkamp 《Biometrics》2012,68(3):893-901
Summary This article considers the topic of finding prior distributions when a major component of the statistical model depends on a nonlinear function. Using results on how to construct uniform distributions in general metric spaces, we propose a prior distribution that is uniform in the space of functional shapes of the underlying nonlinear function and then back‐transform to obtain a prior distribution for the original model parameters. The primary application considered in this article is nonlinear regression, but the idea might be of interest beyond this case. For nonlinear regression the so constructed priors have the advantage that they are parametrization invariant and do not violate the likelihood principle, as opposed to uniform distributions on the parameters or the Jeffrey’s prior, respectively. The utility of the proposed priors is demonstrated in the context of design and analysis of nonlinear regression modeling in clinical dose‐finding trials, through a real data example and simulation.  相似文献   
9.
黑龙江省乌裕尔河流域丹顶鹤等珍稀涉禽航空调查报告   总被引:6,自引:0,他引:6  
利用Y-11型单翼轻型飞机,航高100米,航速140公里/小时,采用且测全区调查方法,对黑龙江省乌裕尔河流域丹顶鹤等涉禽进行了航空调查,续航里程2184公里,调查面积共计为209,000公顷。结果发现调查区内有丹顶鹤(Orus japoncnsis)173只,白枕鹤(Grus vipio)19只,白鹤(Grus leucogeraous)24只,白鹳(Ciconia ciconia)19只等。  相似文献   
10.
Piazzesi et al. [G. Piazzesi, L. Lucii, V. Lombardi, J. Physiol. 545 (2002) 145–151] made a study on the muscle transients due to step changes in force using improved time resolution and recorded filament movement and shortening velocities in the four phases. They point to Phase 2 and to Phase 4 (working muscle) and claim that their results do not contradict the swinging-cross-bridge (SCB) model which has a much-quoted constant power stroke of about 150 Å (their value of 70 Å was smaller). Siding with the SCB model, they nevertheless record that the power stroke decreases with load. We are pleased with this experimental result as it conforms to our theory, published in 1996, of an impulsive model with a much smaller step-size distance z (≈20 Å). Using their data we obtain precise interval times and estimates of filament movement in Phase 2 and in working muscle. Our first result is that the time frames (interval times) for Phase 2 are the same as in working muscle. Moreover, we demonstrate that the authors’ data verify the correctness of our calculated z values. There are eight active ATP events in Phase 2 in time frame t compared to one in working muscle in the same time frame t. This gives, for the first time, precise numbers for contractile events. We show that the SCB model is incorrect and our analysis supports the impulsive model with a much smaller filament (zero-load) motion, ≈20 Å per ATP split.  相似文献   
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