基于双目立体视觉的重叠柑橘空间定位

果实的精准识别和定位是智能采摘面临的难题之一。基于双目立体视觉,提出了一种针对户外重叠柑橘的三维空间定位方法。首先,从双目左右图像中提取重叠柑橘果实轮廓并进行高斯平滑,通过曲率分析,找出异常的轮廓像素点;其次,依次连接相邻两个异常像素点,分析该线段上的像素点到柑橘轮廓的距离,在相邻两正常线段的交点处完成重叠柑橘轮廓分割,并通过寻找异常线段剔除对应的非柑橘轮廓像素点;再者,采用最小二乘椭圆拟合方法重建柑橘目标轮廓,并获取柑橘的中心;最后,根据双目极线约束和图像相似度,对重叠柑橘中心点进行匹配,并基于视差原理计算柑橘中心的深度值及三维空间坐标,确定重叠柑橘的遮挡关系。户外实验结果表明,所提出的方法定位误差为6.38 mm,满足柑橘采摘机器人户外采摘作业的定位精度要求。     

秸秆复合有机酿热物对大棚土壤环境的影响

为解决黑龙江省早春大棚土壤温度低及设施土壤环境恶化问题,以‘千禧’番茄为材料,研究秸秆+牛粪(NGH)、秸秆+马粪(MGH)、秸秆+羊粪(YGH)、单一秸秆(JG),以未进行反应堆技术为对照(CK),对早春大棚‘千禧’番茄土壤温度、土壤理化性状、酶活性及微生物群落结构的影响。结果表明,与对照相比,各处理降低了土壤pH,提高了土壤温度、土壤EC、碱解氮、速效钾、有机质含量及土壤蔗糖酶、脲酶、磷酸酶、过氧化氢酶活性。经过秸秆生物反应堆处理的20 cm土层温度有明显的提升,其中秸秆+羊粪处理在反应启动后提升土壤温度效果最好;秸秆+羊粪(YGH)处理提高了土壤速效磷含量,是对照的2倍;秸秆+羊粪(YGH)处理土壤中4种酶活性均处于最高水平,分别比对照提高了91.9%、220%、18.5%、7.3%。各处理微生物多样性指数均显著高于对照,变化规律一致为秸秆+羊粪(YGH)>秸秆+牛粪(NGH)>秸秆+马粪(MGH)>秸秆(JG)>对照(CK);秸秆+羊粪(YGH)及秸秆+牛粪(NGH)处理对糖类、氨基酸类、酯类、醇类、胺类、酸类6类碳源的利用能力最强,显著高于其他处理和对照。应用主成分分析和聚类分析方法将大棚番茄土壤分为4个等级,秸秆+羊粪(YGH)处理为第一级,秸秆+牛粪(NGH)处理为第二级,秸秆+马粪(MGH)及单一秸秆(JG)处理为第三级,对照(CK)为第四级。应用秸秆复合有机酿热物生物反应堆促进了土壤环境的改善,以秸秆+羊粪(YGH)作为复合有机酿热物效果最佳。     

白斑狗鱼仔、稚鱼的摄食与生长

对白斑狗鱼(Esox luciusL innaeus)的仔、稚鱼的摄食与生长及不可逆点作了实验研究。结果证明:初孵仔鱼全长7.74±0.56 mm,卵黄囊容量3.81±1.07 mm3。孵化8 d仔鱼开始摄食,以桡足类的剑水蚤为主。11 d仔鱼卵黄囊消失,在仔鱼卵黄囊逐渐被吸收的11 d内,前7 d营内源性营养,后4 d则营混合性营养。17 d内平均日增长率为7.14%。仔鱼全长(L)与日龄(t)的关系为:L=1.0547t 5.8927。孵化后的第8、9、10、11、12、13天的初次摄食率分别为91.30%、100%、100%、100%、69.57%和35.48%;不可逆点(PNR)发生在孵化后的第13天。     

提高番茄杂交制种质量的技术措施

番茄(Lycopersicon esculentumM ill)由于特定的植物学特征和生理学特性,到目前为止,杂交一代的大规模生产仍然采取人工去雄授粉的方法[1,2]。而人工杂交制种技术性强,影响制种质量的因素很多,如何降低种子成本,提高种子质量,是目前急需解决的问题。提高番茄杂交制种的种子质量     

基于控制区序列分析河鲈遗传多样性

河鲈为我区优质经济鱼类之一,在我国仅分布于新疆阿勒泰地区。为更好的保护和合理开发利用这一有限资源,我们基于mtDNA控制区序列对额尔齐斯河-乌伦古河水系的5个野生群体进行了遗传多样性和遗传结构进行了研究。PCR-SSCP标记结果显示,18个单倍型分布于5个群体的100个个体中。对这18个单倍型个体的mtDNA控制区序列克隆和测序,最终确定13个单倍型,检测到14个变异位点,占分析序列的1.60%。河鲈总种群表现高的单倍型多样度（0.942±0.034）和偏低的核苷酸多样度（0.00242±0.00450）。Tajima’s D和Fuand Li’s D指数的估算结果显示,河鲈5个群体遗传分化不显著（P〉0.1）,具有较稳定的种群结构。YBW,BEJH和LSW群体间存在着一定的基因流（Nm〉1）,WLGH群体与其他群体间的基因流水平低（Nm〉0.6）,存在着由于遗传漂变而产生分化的危险。5个群体间的单倍型序列差异为0.003,说明单倍型间未出现分化。     

Histological alterations in gills of shrimp Litopenaeus vannamei in low‐salinity waters under different stocking densities: Potential relationship with nitrogen compounds

Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp /m²) were examined weekly over a culture cycle in tanks with low‐salinity water (1.9 g/L) and zero water exchange. Results showed survival rates of 87.7 and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, electrical conductivity and chlorophyll a were not significantly (p > .05) different between modules. In contrast, the concentrations of nitrogen compounds were significantly (p < .05) different between modules, except nitrite‐N (M2 were 2.31 ± 1.38 mg/L N‐TAN, 0.18 ± 0.49 mg/L N‐NO₂^? and 6.83 ± 6.52 mg/L N‐NO₃^?; in M1: 0.97 ± 0.73 mg/L N‐TAN, 0.05 ± 0.21 mg/L N‐NO₂^? and 0.63 ± 0.70 mg/L N‐NO₃^?). When waters of both modules reached higher levels of ammonia and nitrite, histological alterations were observed in gills. The histological alterations index (HAI) was higher in M2 (5‐112) than in M1 (2‐22).     

额尔齐斯河银鲫形态学及COI基因序列分析

采用传统形态学方法和线粒体COI基因序列分析对额尔齐斯河银鲫(Carassius auratus gibelio)两个群体的形态和遗传差异进行了比较。结果显示:通过对8个可量性状和20个框架数据的主成分分析可以看出,两个群体分别占据两个不相重叠的区域,两个群体在形态上存在明显分化。COI基因序列分析显示,两群体之间遗传距离为0.012,群体间遗传距离是群体内最大遗传距离的4倍,两群体间在编码的氨基酸序列上出现了一处替换,群体遗分化指数值为0.96078,基因流值为0.01,表明群体间缺乏基因交流,群体间有明显的遗传分化。     

Effect of in vitro exposure to Vibrio vulnificus on hydroelectrolytic transport and structural changes of sea bream (Sparus aurata L.) intestine

The everted gut sac technique has been used to investigate the effect of Vibrio vulnificus on water and electrolyte (Na⁺, K⁺, Cl⁻, HCO₃ ⁻) transport on the intestine of sea bream (Sparus aurata L.). Both the anterior and the posterior intestine were incubated in a medium containing 10⁸ V. vulnificus cells ml⁻¹ at 25°C for 2 h. The presence of V. vulnificus resulted in a significant reduction (P < 0.05) of water absorption in the anterior intestine, while sodium absorption in the anterior (P < 0.01) and posterior (P < 0.05) intestine was elevated. Chloride absorption was increased, but the changed was not significant, while potassium absorption decreased significantly (P < 0.05), but only in the posterior intestine. Incubation the sea bream intestine with V. vulnificus did not affect carbonate secretion in the anterior segment, whereas high secretion was stimulated in the posterior segment (P < 0.01). Histological evaluations demonstrated damage in the anterior intestine of sea bream that was characterized by the detachment of degenerative enterocytes, alterations in the microvilli, and the presence of a heterogenous cell population, indicating inflammation. Based on our results, we conclude that V. vulnificus caused cell damage to the intestine of sea bream and that the anterior intestine is more susceptible than the posterior part of the intestine. Several hypotheses are suggested to explain our observations, such as the presence of higher numbers of villosities in the anterior intestine than in the posterior one and/or the presence of endogenous bacteria in the posterior intestine which may have a protector role.     

Effect of polyamines on intracellular calcium of the rat cardiomyocytes with anoxia and reoxygenation

AIM: To study the effect of extrogenous low concentration polyamine on cardiomyocyte calcium overload caused by anoxia and reoxygenation. METHODS: Enzymatically isolated rat ventricular myocytes were perfused with normal Tyrode solution for 8 min, then change to anoxia solution for 32 min, at last back to normal Tyrode solution perfusion for 8 min to establish the cardiomyocyte model of anoxia and reoxygenation. Spermine was added extracellularly to the bath before anoxia and spermine, spermidine or putrescine was added extracellularly after reoxygenation. Intracellular calcium fluorescence intensity (FI) was measured continuously by laser scan confocal microscope (LSCM). RESULTS: In the unstimulated state, exogenous spermine (1 mol/L) did not change resting ［Ca2+］i in the rat cardiomyocytes. Adding spermine before anoxia antagonized the ［Ca2+］i elevating caused by anoxia/reoxygenation. Adding spermine after reoxygenation also lowed the enhanced ［Ca2+］i caused by reoxygenation. Considering the potency of two conditions, the former was more efficacious than the later. Spermidine and putrescine also lowed the enhanced ［Ca2+］i caused by reoxygenation, but they were less efficacious than spermine. CONCLUSIONS: The results indicate that spermine given before anoxia or after reoxygenation, antagonized or lowed the cardiomyocytes calcium overload caused by anoxia/reoxygenation, but the later was weaker than the former. The order of potency of the polyamine lighten cardiomyocytes calcium overload caused by anoxia/reoxygenation was spermine>spermindine>putrescine.     

The effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen, on urinary bladder motility in guinea pigs

The aim of this research was to observe the effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen (HBO), on the motility of urinary bladder muscle in guinea pigs. In the experimental groups, mesna and cyclophosphamide were intraperitoneally injected at a dose of 21.5 mg/kg and 68.1 mg/kg, respectively. For the combination of mesna and cyclophosphamide, one dose of mesna was injected 20 min before cyclophosphamide administration and three additional injections of mesna were repeated every three hours. A total of 8 HBO exposures were performed at 2.8 ATA for 90 min twice daily for another experimental group. In the HBO and cyclophosphamide combined group 5 HBO exposures were given prophylactically before cyclophosphamide. The combination of mesna, HBO and cyclophosphamide was administered by the same procedure. The contractions obtained in response to acetylcholine (ACh, 10(-4) M) in the control group were reduced using cyclophosphamide and HBO individually, but not by mesna. However, the contractions belonging to the various combinations of these three agents were not different from those seen in the control group. On the other hand, the combinations of cyclophosphamide, mesna and HBO showed higher responses to ACh than the groups in which cyclophosphamide and HBO were used individually, while the responses elicited by the cyclophosphamide and HBO combination were greater than those seen in the group treated with HBO only.