A statistical model of the reproduction of aphids

1. The logistic function has been generally used to describe the reproductive process of a “population” of animal. However, this model can not give us any information about the reproductive process of “individuals” in the population. In this study a statistical model on the basis of the reproduction of individuals of barley aphid is presented to find the proportion of the mature individuals, the heterogeneity in reproductive ability of the aphids, etc.
2. The model is constructed as follows:
3. The probability that j insects are found on a plant at time t₀ is represented as Q(j).
4. The probability that h individuals of j have reproductive ability, say, mature individuals, in the period t₀ to t₁ is represented as B(h/j)=_jC_hw^h(1−w)^j−h, where w is the proportion of mature individuals.
5. In a population with a homogeneous reproductive ability, the probability that each parent lays i offspring in the period t₀ to t₁ is represented as P(i/m)=e^−mmⁱ/i!, where m is mean. And, in a population, m changes according to the gamma distribution. Hence the probability that a parent lays i offspring between t₀ and t₁ is represented as , where p and k are parameters of negative binomial distribution. The probability that h parents on a plant lays s offspring is represented as .
6. From the assumptions mentioned above, the probability that s offspring are to be found at time t₁ on a plant with the original j individuals at time t₀ is represented by
7. The experimental populations were demonstrated to fit well to the model.

     

Comparison of four molecular markers in measuring relationships among the wild potato relatives Solanum section Etuberosum (subgenus Potatoe)

We evaluated chloroplast DNA (cpDNA), isozymes, single to low-copy nuclear DNA (RFLPs), and random amplified polymorphic DNAs (RAPDs) in terms of concordance for genetic distance of 15 accessions each of Solanum etuberosum and S. palustre, and 4 accessions of S. fernandezianum. These self-compatible, diploid (2n=24), and morphologically very similar taxa constitute all species in Solanum sect. Etuberosum, a group of non-tuber-bearing species closely related to Solanum sect. Petota (the potato and its wild relatives). Genetic distance and multidimentional scaling results show general concordance of isozymes, RFLPs and RAPDs between all three taxa; cpDNA shows S. etuberosum and S. palustre to be more similar to each other than to S. fernandezianum. Interspecific sampling variance shows a gradation of resolution from allozyme (low) to RAPD to RFLP (high); while intraspecific comparisons graded from RFLPs (low) to RAPDs (high; lack of sufficient allozyme variability within species precluded comparisons for allozymes). Experimental error was low in RFLPs and RAPDs.Names are necessary to report factually and available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable     

MRI在剖宫产术后瘢痕妊娠诊疗路径中的应用价值

摘要 目的：探讨磁共振成像在剖宫产术后瘢痕妊娠（cesarean scar pregnancy,CSP）诊疗路径中的应用价值。方法：回顾性分析24例经手术和（或）病理证实为瘢痕妊娠的孕妇临床和影像检查资料,记录MRI上妊娠囊位置、大小、T1、T2信号强度、妊娠囊类型、妊娠囊与子宫前壁下段肌层及膀胱的关系,分析MR特征对临床诊疗路径的应用价值。结果：24例妊娠囊均位于子宫下段,为圆形或卵圆形,11例妊娠囊为单纯囊性,12例妊娠囊为混杂包块型,1例因清宫术后行MR,未见明确妊娠囊,仅见子宫下段混杂信号。10例妊娠囊附着处子宫肌厚度不可测量,余14例妊娠囊附着处子宫肌厚度约0.9～5.0 mm,平均2.5±1.1 mm。据此,CSP分型为I型5例,II型7例,III型12例。结论：MRI能较好的评估CSP, 在CSP诊疗路径中的应用价值较大。     

气压治疗仪联合那屈肝素预防剖宫产术后下肢静脉栓塞的临床研究

摘要 目的：探究气压治疗仪联合那屈肝素预防剖宫产术后下肢静脉栓塞（DVT）的临床效果。方法：选取2021年1月～2022年8月长沙市妇幼保健院收治的172例剖宫产孕妇,以随机数字表法按1:1比例分为联合组、常规组,各86例。常规组采用那屈肝素预治疗,联合组采用气压治疗仪联合那屈肝素治疗。比较两组DVT发生率;术前、术后5 d凝血功能指标[凝血酶时间（TT）、纤维蛋白原（FIB）、活化部分凝血活酶时间（APTT）、凝血酶原时间（PT）]、血液流变学指标[全血高切黏度、血浆黏度、全血低切黏度];术前、术后1 d、5 d大小腿腿围;术前、术后1 d、3 d、5 d疼痛视觉模拟量表（VAS）评分。结果：联合组DVT发生率3.49%较常规组11.63%低（P＜0.05）;术后5 d联合组PT、APTT、TT较常规组高,FIB较常规组低（P＜0.05）;术后5 d联合组全血高切黏度、血浆黏度、全血低切黏度较常规组低（P＜0.05）;术后1 d、5 d联合组大小腿腿围较常规组低（P＜0.05）;术后1 d、3 d、5 d联合组VAS评分较常规组低（P＜0.05）。结论：气压治疗仪联合那屈肝素能有效改善剖宫产产妇术后凝血功能及血液流变学,缓解下肢肿胀,减轻术后疼痛,减少DVT的发生。     

急诊危重孕产妇5分钟紧急剖宫产的临床效果及新生儿不良结局的危险因素分析

摘要 目的：探讨急诊危重孕产妇5分钟紧急剖宫产的临床效果,并分析新生儿不良结局的危险因素。方法：回顾性分析2018年1月~2022年6月在河北省儿童医院妇产科收治的急诊危重孕产妇139例的临床资料。根据急诊剖宫产流程分为对照组（n=68,常规紧急剖宫产流程下进行手术）及观察组（n=71,5分钟紧急剖宫产）。观察两组孕产妇的手术情况、手术反应时间、孕产妇并发症、新生儿不良结局发生率。采用多因素Logistic回归模型分析新生儿不良结局的危险因素。结果：两组住院时间、术中出血量、术中输血情况组间对比,未见统计学差异（P>0.05）。与对照组相比,观察组进手术室至手术开始时间、决定手术至胎儿娩出的时间间隔（DDI）、决定手术至进手术室时间、手术开始至胎儿娩出时间均更短,新生儿不良结局发生率、并发症发生率更低（P<0.05）。根据新生儿不良结局将孕产妇分为不良组（n=38）、良好组（n=101）。单因素分析结果显示：新生儿不良结局与受教育程度、新生儿体重、孕周、剖宫产类型、DDI、妊娠合并症、采用辅助生殖技术有关（P<0.05）。多因素Logistic回归分析结果显示,受教育程度为小学及其以下、新生儿体重偏低、剖宫产类型为I类剖宫产、孕周偏短、DDI偏长均是新生儿不良结局的危险因素（P<0.05）。结论：急诊危重孕产妇5分钟紧急剖宫产可缩短各项手术反应时间,降低孕产妇并发症和新生儿不良结局发生率。此外,新生儿不良结局的发生与受教育程度、新生儿体重、剖宫产类型、孕周、DDI等因素有关。     

PHOTOADAPTATION AND THE “PACKAGE” EFFECT IN DUNALIELLA TERTIOLECTA (CHLOROPHYCEAE)1

In the marine unicellular chlorophyte, Dunaliella tertiolecta Butcher, the spectrally averaged m vivo absorption cross section, normalized to chlorophyll a (so-called a* values), vary two-fold in response to changes in growth irradiance. We used a kinetic approach to examine the specific factors which account for these changes in optical properties as cells photoadapt. Using Triton X-100 to solubilize membranes, we were able to differentiate between “package” effects and pigmentation effects. Our analyses suggest that 43–49% of the variability in a* is due to changes in pigmentation, whereas 51–57% is due to the “package” effect. Further analyses revealed that changes in cell sue did not significantly affect packaging, while thylakoid stacking and the transparency of thylakoid membranes were important factors. Our results suggest that thylakoid membrane protein/lipid ratios change during photoadaptation, and these changes influence the effective rate of light harvesting per unit chlorophyll a.     

The pollen-specific LIM protein PLIM-1 from sunflower binds nucleic acids in vitro

The protein PLIM-1 (formerly SF3) from sunflower is expressed exclusively in mature, free pollen. It contains two LIM domains associated with an acidic C-terminus comprising six copies of the pentapeptide motif (A,T,S) (E,D) TQN. We have expressed the pollen protein as well as some of its mutant forms inEscherichia coli and have used the bacterially produced proteins to study interactions with nucleic acids. Our studies show that the protein binds DNA and RNA in vitro to form large complexes, while mutant polypeptides containing either a single LIM domain or a destabilized first or second LIM domain do not. Although these data suggest that the biological function of PLIM-1 involves interactions with nucleic acids, its role in pollen development remains unclear.     

Purification of restriction endonuclease XcyI from Xanthomonas cyanopsidis

A new Type II restriction endonuclease XcyI, purified from Xanthomonas cyanopsidis 13D5, is an isoschizomer of SmaI and XmaI that cleaves at the nucleotide sequence 5'-C decreases CCGGG-3' of double-stranded DNA. The single restriction activity present in this strain permits rapid purification of 8000 units of cleavage activity from 10 g of freshly harvested cells. The resulting XcyI preparation is free of contaminating nuclease activities that interfere with in vitro manipulation of DNA.     

Use of lambda phasmids for deletion mapping of non-selectable markers cloned in plasmids

A nonselectable gene carried on a poorly selectable recombinant plasmid has been physically mapped by deletion analysis. Our method involved cloning the plasmid into a coliphage lambda vector and treating the recombinant phage with a chelator. Virtually all particles surviving this treatment carried large deletions within the plasmid insert. Further deletion analysis was done by inserting a selectable lambda sequence into one such deletion derivative and repeating the chelator selection. Chelator selection was also used to isolate deletions constructed in vitro. The deleted phage are readily characterized by restriction mapping, and the gene in question scored after infection of a mutant host strain. These techniques have enabled us to physically assign the cyclopropane fatty acid synthase gene of Escherichia coli to 0.8 kb of a 16-kb segment after characterizing only a small number of isolates. This approach should be generally useful in the mapping of plasmids for which no convenient method exists for selecting or scoring the gene in question.