应用人工神经网络评价湖泊的富营养化

应用人工神经网络方法,以化学需氧量、总氮、总磷和透明度作为评价参数,经反复尝试,构建了具有４层结构用于评价湖泊富营养化的误差逆传播网络．其输入层有４个神经元,２个隐含层也各有４个神经元,输出层有１个神经元．以太湖富营养化评价标准作为样本模式提供给网络,按照误差逆传播网络的学习规则对网络进行训练,经过３７６８４次学习后,网络达到预先给定的收敛标准．使网络具备了识别湖泊富营养化程度的功能．应用该网络对我国１７个湖泊的富营养化程度进行评价,操作过程简便易行,评价结果切合实际,展示了这种方法的一系列优点．     

How habitat disturbance benefits geckos: Conservation implications

I here provide some field observations and literature data showing that egg laying site availability could be the main limiting factor for most arboreal gecko population dynamics. Several natural (typhoons, volcanism, sea level variations) or human-mediated habitat modifications (garden openings in forested areas) provide enough habitat disturbances to significantly increase reproductive outputs in island gecko populations. Such observations, however, also apply to continental populations. Our observations suggest that artificial shelter and egg laying site creation could easily allow populations to increase and also supply easier access to arboreal species for ecological or biodiversity studies. Furthermore, our observations also point out that occurrence in man-made habitats and genetic uniformity of most widespread island lizards should not be considered as evidence of their recent introduction through human agency.     

Initiation of flight muscle apoptosis and wing casting in the red imported fire ant Solenopsis invicta

Abstract Newly‐mated Solenopsis invicta flight queens cast (shed) their wings within 24 h. An examination of their flight muscle cells reveals numerous apoptotic (terminal deoxynucleotidyl transferase mediated dUTP nick end labelling positive) nuclei. By contrast, flight muscle cells of mature alate virgin (MAV) females removed 24 h earlier from a managed laboratory colony exhibit neither wing casting nor the presence of apoptotic nuclei. Using MAV‐females, the initiation of flight muscle apoptosis and wing casting is compared with artificial mating using seminal fluid with sperm, seminal fluid with no sperm, saline as a negative control, the mating flight as simulated in the laboratory, elevated CO₂ exposure, application of methoprene (a juvenile hormone analogue), or injection of 20‐hydroxyecdysone. Numerous apoptotic nuclei are revealed in the flight muscle cells of mated dealate females 24 h after a natural mating flight but not in MAV‐females controls. Only artificial mating of MAV‐females reveals a similar pattern of apoptotic nuclei flight muscle 24 h after insemination. None of the other factors tested induces flight muscle cell apoptosis in MAV‐females. Methoprene dissolved in methyl ethyl ketone, at a concentration of 0.44 ng per μL per ant, stimulates 90% of MAV‐females to shed their wings within 24 h, as opposed to 10% or less wing shedding for the methyl ethyl ketone control and all other treatments.     

几丁糖和透明质酸钠对宫腔粘连的防治效果及并发症的影响

目的:探讨几丁糖和透明质酸钠对宫腔防粘连效果及并发症的影响。方法:回顾性分析本院2013年9月~2014年9月收治的150例人工流产患者的临床资料,均实施常规无痛人流手术,按照术前处理方式的不同分为空白对照组(50例)和几丁糖组(50例)、透明质酸钠组(50例)。术后随访6个月,观察两组的阴道流血持续时间和月经复潮时间,以及术后第14 d子宫内膜厚度和术后粘连发生情况、并发症发生情况,并进行比较。结果:术后几丁糖组和透明质酸钠组的阴道流血持续时间和月经复潮时间,以及术后第14 d天子宫内膜厚度和术后粘连发生情况、并发症发生率与空白对照组之间均存在统计学差异,各项指标均显著优于空白对照组,P0.05,但几丁糖组和透明质酸钠组二组间比较差异无统计学意义,P0.05。结论:对人工流产患者予以几丁糖和透明质酸钠处理均可以获得良好的临床效果,有效减少术后粘连以及各种并发症的出现。     

PONDR-FIT: A meta-predictor of intrinsically disordered amino acids

Protein intrinsic disorder is becoming increasingly recognized in proteomics research. While lacking structure, many regions of disorder have been associated with biological function. There are many different experimental methods for characterizing intrinsically disordered proteins and regions; nevertheless, the prediction of intrinsic disorder from amino acid sequence remains a useful strategy especially for many large-scale proteomic investigations. Here we introduced a consensus artificial neural network (ANN) prediction method, which was developed by combining the outputs of several individual disorder predictors. By eight-fold cross-validation, this meta-predictor, called PONDR-FIT, was found to improve the prediction accuracy over a range of 3 to 20% with an average of 11% compared to the single predictors, depending on the datasets being used. Analysis of the errors shows that the worst accuracy still occurs for short disordered regions with less than ten residues, as well as for the residues close to order/disorder boundaries. Increased understanding of the underlying mechanism by which such meta-predictors give improved predictions will likely promote the further development of protein disorder predictors. Access to PONDR-FIT is available at www.disprot.org.     

不同低温胁迫下粳稻耐冷种质的孕穗期耐冷性比较

为粳稻孕穗期耐冷标准品种的建立和耐冷遗传育种研究提供优异基因资源,利用人工低温气候室,采用15℃、17℃、19℃3种胁迫温度,4d和6d两种胁迫时间,3×2交互式设计的方法,对来自黑龙江、吉林、辽宁和云南的12份粳稻种质进行了孕穗期耐冷性强度的研究。结果表明,随着低温胁迫的增强,各水稻品种的平均空壳率都随之增加;在15℃/6d胁迫下,供试品种平均空壳率的方差和变异系数达到最大,该胁迫强度可被选用于孕穗期强耐冷种质的筛选。依据15℃/6d胁迫下供试品种平均空壳率的方差分析及多重比较结果,空育131和龙稻3号具有极强的孕穗期耐冷性。不同地区可根据参试品种在本试验中的耐冷表现,并结合当地水稻种植区的光温条件选择相应的耐冷标准品种。     

Deep intra-uterine artificial inseminations using cryopreserved spermatozoa in beluga (Delphinapterus leucas)

Artificial insemination (AI) with liquid-stored spermatozoa and sperm cryopreservation using directional freezing (DF) have been successful in the beluga. This study built on this foundation to develop a deep intra-uterine AI technique with frozen-thawed semen in beluga. Forty-two ejaculates from one male were cryopreserved using DF technology and subsequently used for 10 insemination attempts with seven females. Percentage pre- and post-thaw progressive motility and viability were (mean ± SD) 73.0 ± 12.2, 38.4 ± 8.8, 88.0 ± 0.1, and 59.3 ± 15.7%, respectively. A series of GnRH injections (3 x 250 μg, IV, 1.5 to 2 h apart) were used to induce ovulation, once a growing follicle >2.5 cm in diameter was visualized via trans-abdominal ultrasonography. Artificial insemination was performed at 30.1 ± 3.8 h post-initial GnRH injection with semen deposited in the uterine horn, 92.6 ± 16.2 cm beyond the genital opening using a flexible endoscope. The external cervical os (cEOS) was located beyond a series of 5 to 10 vaginal rings, 44.8 ± 9.3 cm from the external genital opening. The internal bifurcation of the uterus was 27 ± 6.8 cm beyond the cEOS. Ovulation occurred at 8.5 ± 7.6 h post-AI. Two of 10 inseminations (20%) resulted in pregnancy. The first pregnancy resulted in twins; both calves were born 442 d after AI, with one surviving. The second pregnancy is ongoing. These findings represent the first successful application of AI using frozen-thawed semen in beluga, and are important examples of how assisted reproductive technologies can provide tools for the global management of threatened species.     

Strategies to improve pregnancy per insemination using sex-sorted semen in dairy heifers detected in estrus

The objective was to improve pregnancy per artificial insemination (P/AI; 35-42 d after AI) in virgin Jersey heifers bred by AI of sex-sorted semen after being detected in estrus. Giving 100 μg of GnRH at first detection of estrus, with AI 12 h later, did not affect P/AI in Experiment I [GnRH = 47.2% (100/212) vs. No GnRH = 51.7% (104/201); P = 0.38] or Experiment II [GnRH = 53.1% (137/258) vs. No GnRH = 48.6% (122/251); P = 0.43]. In these two experiments, estrus detection was done with tail-head chalk or a HeatWatch^® system, respectively. In Experiment III, a single insemination dose (2.1 × 10⁶ sperm) 12 h after estrus detection (n = 193), a double dose at 12 h (n = 193), or a double dose involving insemination 12 and 24 h after estrus detection (n = 190) did not affect P/AI (87/193 = 45.1%, 85/193 = 44.0%, and 94/190 = 49.5%, respectively; P = 0.51). However, P/AI was influenced by the number of AI service (First, 115/208 = 55.3%^a; Second, 94/204 = 46.1%^a; and Third, 57/165 = 34.8%^b; P = 0.004). In Experiment IV, the P/AI of heifers inseminated from 12 to 16 h after the onset of estrus (40/106 = 37.7%) was less (P = 0.03) than those inseminated from 16.1 to 20 h (85/164 = 51.8%), and 20.1 to 24 h (130/234 = 55.6%). However, the P/AI for heifers inseminated from 24.1 to 30 h (61/134 = 45.5%) did not differ from that of any other interval. In conclusion, in Jersey heifers inseminated with sex-sorted semen, P/AI was not significantly affected by giving GnRH at detection of estrus or a double insemination dose, but it was higher with AI 16.1 to 24 h vs. 12 to 16 h after the onset of estrus.     

Parthenogenetic development of domestic cat oocytes treated with ionomycin, cycloheximide, roscovitine and strontium

The objective was to evaluate the parthenogenetic activation of domestic cat oocytes. Cumulus-oocyte complexes matured for 36 h were subjected to three protocols of parthenogenetic activation: Group 1 - ionomycin + cycloheximide; Group 2 - ionomycin + roscovitine; and Group 3 - ionomycin + strontium. As a control, a fourth group of oocytes were cultured in the absence of any activation agent. In all groups, embryos were cultured in SOFaa for 72 h after activation and evaluated for activation rate, cleavage, and embryonic development using Hoechst33342. There were no significant differences among the three treated groups for rates of activated oocytes (70.1 ± 4.3, 75.5 ± 4.7, and 61.9 ± 7.2%, for Treatments 1, 2, and 3 respectively; mean ± SEM), or cleavage (48.1 ± 5.9, 47.4 ± 3.8, and 33.3 ± 6.8%). However, activation and cleavage rates were higher (P < 0.05) than those in the control group (35.5 ± 6.4 and 11.8 ± 4.0%). There were no significant differences among treatment groups for proportion of embryos with 2-10 cells, 10-16 cells, and morulas. In the Control group, the embryo production rate was lower (P < 0.05), although the activation rate was high. The authors concluded that all three treatments effectively induced parthenogenetic activation of domestic cat oocytes. However, to optimize the use of strontium and roscovitine, a dose response and the effect of the presence of Ca⁺⁺ in the medium requires further study.     

喀斯特峰丛洼地植被不同演替阶段土壤磷酸酶活性

以桂西北典型喀斯特峰丛洼地为试验对象,研究了4个不同植被演替阶段土壤碱性磷酸酶活性及其与土壤理化性质的关系。结果表明:土壤磷酸酶活性随演替阶段和土层深度变化显著;随坡位变化不显著。不同演替阶段土壤磷酸酶活性表现为原生林次生林≈乔灌林草地;磷酸酶活性随土壤深度的增加而降低,且各层次之间差异显著。相关分析表明:磷酸酶活性与土壤有机质、全氮、全磷、碱解氮、速效磷、速效钾、pH值、粉砂、砂粒含量存在显著的正相关;与土壤全钾、容重、粘粒含量呈负相关。典范对应分析(CCA)结果表明:演替阶段和裸岩率对土壤磷酸酶活性影响很大;坡位、坡度和坡向也有一定影响。