利用候选区域的多模型跟踪算法

跟踪过程中发生的尺度变化、形变、遮挡是导致模型漂移的重要原因。为了克服模型漂移对鲁棒跟踪的影响,本文提出了一种利用多判别式模型和候选区域的跟踪算法。首先,该算法采用候选区域替代传统的滑动采样,适应跟踪过程中目标的位移和尺度变化。接下来,为了提高目标的表征能力,先用预训练网络提取整幅图片的深度特征,再通过感兴趣区域采样层(ROI pooling layer)快速提取每一个候选区域的深度特征,进一步提高跟踪算法的鲁棒性。最后,运用多模型选择机制进行回撤过去错误的模型更新,并通过调整搜索区域实现对目标的重检测,有效抑制了模型漂移对鲁棒跟踪的影响。实验中,本文算法与相关算法在OTB 2013数据库和UAV 20L数据库上进行了对比。结果表明,本文算法在精确度与成功率上均取得了最优性能,并能有效抑制模型漂移对鲁棒跟踪的影响。     

用SSR技术和混合取样方法估算玉米群体间的遗传距离

The factors affecting the binding characteristics of GBSS with starch granule were studied using a wheat (Triticum aestivum) cultivar Chinese Spring with different temperature treatments. After sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, we got GBSS concentration by coomassie brilliant blue G-250(CBB G-250) method. The results showed that the temperature affected the binding of GBSS and starch granule. In 50–80℃, the concentration of GBSS unbound from starch increased with the temperature rising, which the maximal concentration was 11.361 μg mL^-1 at 80℃, while that was reduced when the temperature was 85–95℃. Furthermore, Mg²⁺ could also affect the quantity of GBSS unbound from starch. When Mg2+ concentration was lower than 1.75 mmol L^-1, the concentration of GBSS unbound increased. The lower Mg²⁺ concentration, the higher the concentration of GBSS unbound. However, when Mg²⁺ concentration was higher than 2.5 mmol L^-1, it could restrain GBSS unbinding. These results showed that GBSS bound starch granule by non-covalent bonds. The best GBSS extracting conditions were 55 mmol L^-1 Tris-HCl (pH 6.8), 0.75 mmol L^-1 MgCl₂, 2.3% SDS, 5% 2-ME and 10% glycerol, 15 min in boiling water, or 55 mmol L^-1 Tris-HCl (pH 6.8), 0.75 mmol L^-1 MgCl₂, 2.3% SDS, 5% 2-ME and 10% glycerol, 80℃ 30 min. The results are helpful to investigate 3-D structure of biological activated GBSS and mechanism of GBSS binding with starch granule.     

基因型和环境对玉米籽粒粗蛋白及赖氨酸含量的影响

以河南省生产上主要推广的15个玉米品种为材料,于2004-2005年在8个不同的环境条件下进行了2年多点试验,研究基因型和环境对玉米粗蛋白和赖氨酸含量的影响。结果表明:基因型、环境以及基因型与环境的互作效应对玉米粗蛋白和赖氨酸含量均有显著影响,独立效应大于互作效应,在独立效应中,基因型效应大于环境效应;HE-1、HE-2、豫单101和豫单2002粗蛋白含量高于11%,赖氨酸含量高于0.35%,是较理想的高蛋白、高赖氨酸优质专用的玉米品种;郑州、南阳和洛阳比较适宜种植高蛋白、高赖氨酸优质专用玉米。     

环境对玉米杂交种品质性状的影响研究

以河南省生产上主要推广的15个玉米品种为材料,采用近红外光谱技术,分析了在8个不同生态环境下粗蛋白、粗淀粉、粗脂肪和赖氨酸4个玉米品质性状。结果表明:各性状在品种间、地点间和品种与地点互作间的差异均达到极显著水平。在15个品种中,HE-1、HE-2、豫单2001和豫单2002粗蛋白含量高于11%以上,赖氨酸含量高于0.35%,可作为高蛋白、高赖氨酸优质饲用专用玉米品种;郑单958、浚单20、洛玉1号和郑单18粗淀粉含量在72%以上,可将作为高淀粉工业加工专用玉米品种;HE-1、HE-2的粗脂肪含量在7.5%以上,可将它们作为高油工业加工和优质饲用专用玉米品种。驻马店、郑州和洛阳适宜高蛋白、高赖氨酸优质饲用专用玉米品种的种植;商丘、安阳和周口适宜高淀粉工业加工专用玉米品种的种植;商丘、新乡和郑州适宜高油专用玉米品种的种植。     

Effect of calcium silicate on nutrient use of lowland rice and greenhouse gas emission from a paddy soil under alternating wetting and drying

In intensively irrigated rice cultivation,plant-available silicon(Si)is a crucial nutrient for improving rice productivity.As a source of Si,calcium silicate(CaSiO₃)was amended to evaluate the effect of silicate fertilizer on rice production,nitrogen(N)use efficiency,and greenhouse gas(GHG)emission under alternating wetting and drying in a pot experiment using a tropical soil from a paddy field of the International Rice Research Institute(IRRI)in the Philippines.Four levels of CaSiO     

天目山紫楠种群年龄结构与点格局分析

  目的  研究天目山紫楠Phoebe sheareri种群年龄结构和空间分布格局,有利于更好地保护天目山紫楠种群,为森林管理提供依据。  方法  基于浙江省天目山常绿阔叶林1 hm2(100 m×100 m)样地调查数据,分析了优势种紫楠种群的年龄结构,并按胸径(D_BH)将其分为5个径级,分别为径级1(1.0 cm≤D_BH＜2.5 cm)、径级2(2.5 cm≤D_BH＜10.0 cm)、径级3(10.0 cm≤D_BH＜20.0 cm)、径级4(20.0 cm≤D_BH＜30.0 cm)、径级5(D_BH≥30.0 cm)。同时,应用点格局方法分析了不同径级个体的空间分布格局以及空间关联性。  结果  ①径级1和径级2低龄个体较多,占总统计量的68.95%,径级3个体占23.71%,径级4和径级5高龄个体较少,占7.34%。种群的存活曲线接近DeeveyⅠ型,属于增长型发展模式。②径级1、径级2、径级3、径级4个体以聚集型分布为主,且随着研究尺度的增大,聚集性也越显著,径级5以随机分布为主。③各径级间关系密切,以正关联为主。从小尺度观察,径级1与径级4个体在0~5 m尺度内是负关联,径级3与径级4个体在0~8 m尺度内是负关联,径级3与径级5个体在0~4 m尺度内是负关联。除此之外,其他径级个体之间皆为正关联。从大尺度观察,天目山紫楠种群各径级个体之间基本都呈显著正关联。  结论  天目山紫楠种群属于增长型的发展模式,各径级都呈集群分布,不同径级间的关系密切,以正关联为主。图5表2参24     

玉米根系发育突变体及相关基因研究进展

根系形态以及生理特征与作物养分水分高效利用密切相关。利用根系发育突变体是研究根系结构与功能的主要手段之一。近10多年来,一些玉米根系发育的突变体被鉴定出来,其中包括影响节根发育的rtcs突变体,影响侧根发育的lrt1、slr1、slr2和rum1突变体,还有影响根毛发育的rth1、rth2和rth3突变体,其中部分突变体所对应的基因已经克隆。这些进展有利于人们更深入地认识玉米根系生物学特征在养分水分高效中的作用。     

Cross-fostering in coyotes: Evaluation of a potential conservation and research tool for canids

Cross-fostering has been attempted opportunistically with endangered canids as a means of increasing populations. Due to the usefulness of cross-fostering for conservation, an understanding of factors influencing success rates is essential. Using captive coyotes (Canis latrans) as a model, we assessed the willingness of adult pairs to foster young born to other parents. We assessed the efficacy of fostering pups into existing litters (augmentation) and completely switching litters (replacement). We augmented four litters with two pups of similar age when pups were <7 days old. In addition, we replaced four entire litters when pups were <10 days old. We also augmented litters with pups 3-4 and 6-7 weeks of age. Survival, weight gain, and dominance status of pups were monitored for six weeks and compared to four control litters to determine success. All complete litter replacements were successful with survival rates among replaced pups (89.5%) similar to those of control litters (90%). For augmented litters, pup survival was dependent on the age at which fostering occurred. All pups fostered into 4 litters at <1 week of age survived beyond 6 weeks of age, two of three fostering attempts with 3-4-week-old pups succeeded, while neither of two attempts to foster 6-week-old pups succeeded. Surviving fostered pups appeared to be at no disadvantage. Weight gains were similar for pups in all treatments, and there was no evidence of reduced dominance status among fostered pups as compared to natal pups in the same litters. These results illustrate that genetic relatedness is not essential for successful fostering and does not appear to alter dominance patterns; however the age at which pups are fostered may affect the success of fostering attempts.     

Sheep immunoglobulins and their transmission to the neonatal lamb

Extract

In the past decade great strides have been made in clarifying the types of immunoglobulins found in various species of domestic animals. This review summarizes the information presently* * This review cites material published up to the end of 1976. available on sheep immunoglobulins — their classes, quantity and distribution in serum and colostrum. the review also highlights recent studies of fetal immunological competence, presucking lamb serum immunoglobulins, the process by which colostral immunoglobulins are passively transferred to the neonate, and the effects both of colostrum administration and deprivation on the newborn lamb.