2C DNA variation and relationships among New World species of the genus Lupinus (Fabaceae)

The 2C DNA values in 38 species and accessions of the genus Lupinus (Fabaceae) from the New World have been analysed using flow cytometry. They are representatives of North and South American species (the Atlantic and the Andean regions). Estimated 2C DNA values ranged from 1.08 pg in L. pusillus to 2.68 pg in L. albicaulis (both from North America), that is a variation of more than 2.5-fold. The variation for North American lupins was much higher than that for South American ones. Statistical analysis of the data resulted in a grouping that showed for North American lupins some correlation with the length of life cycle. Discussion concerns some aspects of the evolution of the genus.     

Demographic and environmental influences on life-history traits of isolated populations of the Andean catfish Astroblepus ubidiai

In this study, we examined the influence of demographic and environmental variables on the life histories of six remnant populations of the Andean catfishAstroblepus ubidiai (Actinopterygii; Siluriform) located in isolated refuges, and tested six predictions on the relationships between age at maturity, generation time, population density and juvenile and adult growth and survival rates. The three populations inhabiting the watershed with a direct connection to a major lake (Imbakucha) exhibited later maturity, a longer generation time, higher adult survivorship, a higher adult-to-juvenile survival ratio and lower biomass density than those of the adjacent, non-lacustrine watersheds. Across all six populations, there was a strong correlation between mean age at maturity and both the adult-to-juvenile survival ratio and biomass density. Study populations also showed a pattern of inverse density-dependence associated with Allee effects. We conclude that without limitations in the availability of environmental resources, higher population density can be negatively related to age at maturity. This relationship would be expected to become positive when carrying capacity of the systems is reached. Delayed maturity in the Imbakucha populations may be an adaptive response for increasing juvenile survival under stressful conditions.     

Effectiveness of β lactam antibiotics compared with antibiotics active against atypical pathogens in non-severe community acquired pneumonia: meta-analysis

Objective To systematically compare β lactam antibiotics with antibiotics active against atypical pathogens in the management of community acquired pneumonia.Data sources Medline, Embase, Cochrane register of controlled trials, international conference proceedings, drug registration authorities, and pharmaceutical companies.Review methods Double blind randomised controlled monotherapy trials comparing β lactam antibiotics with antibiotics active against atypical pathogens in adults with community acquired pneumonia. Primary outcome was failure to achieve clinical cure or improvement.Results 18 trials totalling 6749 participants were identified, with most patients having mild to moderate community acquired pneumonia. The summary relative risk for treatment failure in all cause community acquired pneumonia showed no advantage of antibiotics active against atypical pathogens over β lactam antibiotics (0.97, 95% confidence interval 0.87 to 1.07). Subgroup analysis was undertaken in those with a specific diagnosis involving atypical pathogens. We found a significantly lower failure rate in patients with Legionella species who were treated with antibiotics active against atypical pathogens (0.40, 0.19 to 0.85). Equivalence was seen for Mycoplasma pneumoniae (0.60, 0.31 to 1.17) and Chlamydia pneumoniae (2.32, 0.67 to 8.03).Conclusions Evidence is lacking that clinical outcomes are improved by using antibiotics active against atypical pathogens in all cause non-severe community acquired pneumonia. Although such antibiotics were superior in the management of patients later shown to have legionella related pneumonia, this pathogen was rarely responsible for pneumonia within the included trials. β lactam agents should remain the antibiotics of initial choice in adults with non-severe community acquired pneumonia.     

基于相关检测的多通道近红外光组织光学测量系统

研制了一套基于相关检测技术的三波长多通道近红外光信号采集系统。采用相敏检波模块CD505R有效提高信噪比。Delphi开发的上位机程序通过串口方式与单片机通信。使用光纤传递光源及探测信号,使系统具有更大的灵活性,适用于多种组织光学特性测量方式。模型实验的结果证明该系统准确可靠,前臂阻断实验表明系统对不同深度组织血氧状况具有较好的测量能力。