Population dynamics of diploid and hexaploid populations of a perennial herb

BACKGROUND AND AIMS: Despite the recent enormous increase in the number of studies on polyploid species, no studies to date have explored the population dynamics of these taxa. It is thus not known whether the commonly reported differences in single life-history traits between taxa of different ploidy levels result in differences in population dynamics. METHODS: This study explores differences in single life-history traits and in the complete life cycle between populations of different ploidy levels and compares these differences with differences observed between different habitat types and years. Diploid and hexaploid populations of a perennial herb, Aster amellus, are used as the study system. Transition matrix models were used to describe the dynamics of the populations, and population growth rates, elasticity values and life-table response experiments were used to compare the dynamics between populations and years. KEY RESULTS: The results indicate that between-year variation in population dynamics is much larger than variation between different ploidy levels and different habitat conditions. Significant differences exist, however, in the structure of the transition matrices, indicating that the dynamics of the different ploidy levels are different. Strong differences in probability of extinction of local populations were also found, with hexaploid populations having higher probability than diploid populations, indicating strong potential differences in persistence of these populations. CONCLUSIONS: This is the first study on complete population dynamics of plants of different ploidy levels. This knowledge will help to understand the ability of new ploidy levels to spread into new areas and persist there, and the interactions of different ploidy levels in secondary contact zones. This knowledge will also contribute to understanding of interactions of different ploidy levels with other plant species or other interacting organisms such as pollinators or herbivores.     

Antidepressant-like effect of a Ginkgo biloba extract (EGb761) in the mouse forced swimming test: role of oxidative stress

EGb761 is a well-defined mixture of active compounds extracted from Ginkgo biloba leaves. This extract is used clinically due to its neuroprotective effects, exerted probably via its potent antioxidant or free radical scavenger action. Previous studies suggest that oxidative stress, via free radical production, may play an important role in depression and animal models for depression-like behavior. Preclinical studies have suggested that antioxidants may have antidepressants properties. The aim of this study was to investigate the antidepressant-like of EGb761 due to its antioxidant role against oxidative stress induced in the forced swimming test, the most widely used preclinical model for assessing antidepressant-like behavior. Male BALB/c mice were pretreated with EGb761 (10 mg/kg, ip) daily for 17 days followed by the forced swimming test and spontaneous locomotor activity. Animals were sacrificed to evaluate lipid peroxidation, different antioxidant enzyme activities, serotonin and dopamine content in midbrain, hippocampus and prefrontal cortex. EGb761 significantly decreased the immobility time (39%) in the forced swimming test. This antidepressant-like effect of EGb761 was associated with a reduction in lipid peroxidation and superoxide radical production (indicated by a downregulation of Mn-superoxide dismutase activity), both of which are indicators of oxidative stress. The protective effect of EGb761 is not related to excitatory or inhibitory effects in locomotor activity, and was also associated with the modulation of serotonergic and dopaminergic neurotransmission. It is suggested that EGb761 produces an antidepressant-like effect, and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects.     

鸡胚尿囊膜（HET-CAM）眼刺激替代试验对产品及原料评价的比较

目的比较鸡胚尿囊膜试验（HET-CAM）作为一种眼刺激替代方法对产品或原料的评价。方法采用HET-CAM和兔眼Draize试验方法,对19种原料和23种化妆品及家用洗涤产品眼刺激性进行检测,对体内体外试验的结果进行统计比较。结果比较体内体外试验,原料和产品的kappa系数分别为0.826,0.531;灵敏度分别为100%,81.8%;特异度分别为85.7%,77.8%。结论 HET-CAM可作为Draize试验的替代试验,HET-CAM系统更适合对单纯化学品原料进行眼刺激试验。     

氮、磷、钾肥配施对桂花品种'金玉台阁'开花性状及叶片中叶绿素和营养元素含量的影响

以桂花品种'金玉台阁'(Osmanthus fragrans'Jinyu Taige')盆栽苗为供试材料,采用"3414"肥料效应试验设计方案,研究了不同单株施用量CO(NH2)2(0.0、1.0、2.0和3.0 g)、NH4H2PO4(0.0、1.5、3.0和4.5 g)和KCl(0.0、0.5、1.0、1.5 g)对秋冬生长期(2014年10月至2015年2月)'金玉台阁'开花性状及叶片中叶绿素和营养元素的影响进行了比较和分析,并筛选出适宜的氮、磷、钾肥施用量.结果表明:与CK〔CO(NH2)2、NH4H2PO4和KCl的单株施用量均为0.0 g〕组相比,各氮、磷、钾肥配施处理组'金玉台阁'的单株产花量、花瓣相对含水量、花径以及叶片中叶绿素、全氮、全磷和全钾的含量总体上显著升高.CO(NH2)2单株施用量对'金玉台阁'单株产花量、叶片中叶绿素含量和全氮含量的影响最大,NH4H2PO4单株施用量对这3个指标的影响次之;NH4H2PO4单株施用量对'金玉台阁'叶片中全磷含量的影响最大;KCl单株施用量对'金玉台阁'花瓣相对含水量、花径及叶片中全钾含量的影响最大.在秋冬生长期内叶片中叶绿素含量呈先降低后升高的趋势,均在12月份降至最低值.通过建立'金玉台阁'单株产花量(y)与CO(NH2)2、NH4 H2 PO4和KCl的单株施用量(分别为xN、xP和xK)间的肥料效应模型,得到的三元二次肥料效应模型为y=1.2027+0.7561×xN+0.2632×xP+0.4590×xK-0.2761×xN2-0.1201×xP2-0.5007×xK2+0.1901×xN×xP-0.0960×xN×xK+0.1185×xP×xK.以单株产花量为目标,'金玉台阁'的CO(NH2)2、NH4 H2 PO4和KCl的最佳单株施用量分别为2.58、3.56和0.86 g.     

Inhibition of intestinal glucose uptake by aporphines and secoaporphines

The effects of aporphines and secoaporphines on glucose uptake by isolated intestinal brush-border membrane vesicles (BBMV) or basolateral membrane vesicles (BLMV) and glucose absorption during in situ intestinal perfusion were studied. Of the tested compounds, N-allylsecoboldine was the most potent glucose uptake inhibitor, with IC50 values of 159 microM and 121 microM, respectively, for uptake by BBMV and BLMV. While thaliporphine competitively inhibited glucose uptake by both membrane preparations, inhibition by N-allylsecoboldine was competitive using BBMV and noncompetitive using BLMV. In addition, N-allylsecoboldine significantly reduced both glucose absorption during in situ intestinal perfusion and blood glucose levels in the oral glucose tolerance test. The results demonstrate that levels of both aporphines and secoaporphines achievable by oral administration have an inhibitory effect on intestinal glucose uptake and suggest that the hypoglycemic effects of these compounds merit attention.     

2株耐低温微生物处理污水模拟试验初报

从下水管道的污泥中分离筛选到耐冷细菌H6和耐冷酵母菌J1,采用此2菌株进行模拟污水低温(8℃)处理试验。H6和J1菌株对模拟污水COD的去除率分别为66.6%和72.2%;H6、J1菌株对有机氮去除率分别为76.9%和64.5%;H6、J1菌株对总磷去除率分别为53.9%和14.0%。说明低温微生物在低温环境的污水处理具有广阔的应用前景。     

Changes in prostate cancer incidence,mortality and survival in relation to prostate specific antigen testing in New South Wales,Australia

BackgroundTo examine changes in prostate cancer incidence and mortality rates, and 5-year relative survival, in relation to changes in the rate of prostate specific antigen (PSA) screening tests and the use of radical prostatectomy (RP) in the Australian population.MethodsProstate cancer stage-specific incidence rates, 5-year relative survival and mortality rates were estimated using New South Wales Cancer Registry data. PSA screening test rates and RP/Incidence ratios were estimated from Medicare Benefits Schedule claims data. We used multiple imputation to impute stage for cases with “unknown” stage at diagnosis. Annual percentage changes (APC) in rates were estimated using Joinpoint regression.ResultsTrends in the age-standardized incidence rates for localized disease largely mirrored the trends in PSA screening test rates, with a substantial ‘spike’ in the rates occurring in 1994, followed by a second ‘spike’ in 2008, and then a significant decrease from 2008 to 2015 (APC −6.7, 95% CI −8.2, −5.1). Increasing trends in incidence rates were observed for regional stage from the early 2000s, while decreasing or stable trends were observed for distant stage since 1993. The overall RP/Incidence ratio increased from 1998 to 2003 (APC 9.6, 95% CI 3.8, 15.6), then remained relatively stable to 2015. The overall 5-year relative survival for prostate cancer increased from 58.4% (95% CI: 55.0–61.7%) in 1981–1985 to 91.3% (95% CI: 90.5–92.1%) in 2011–2015. Prostate cancer mortality rates decreased from 1990 onwards (1990–2006: APC −1.7, 95% CI −2.1, −1.2; 2006–2017: APC −3.8, 95% CI −4.4, −3.1).ConclusionsOverall, there was a decrease in the incidence rate of localized prostate cancer after 2008, an increase in survival over time and a decrease in the mortality rate since the 1990s. This seems to indicate that the more conservative use of PSA screening tests in clinical practice since 2008 has not had a negative impact on population-wide prostate cancer outcomes.     

Rethinking counselling in prenatal screening: An ethical analysis of informed consent in the context of non-invasive prenatal testing (NIPT)

Informed consent is a key condition for prenatal screening programmes to reach their aim of promoting reproductive autonomy. Reaching this aim is currently being challenged with the introduction of non-invasive prenatal testing (NIPT) in first-trimester prenatal screening programmes: amongst others its procedural ease—it only requires a blood draw and reaches high levels of reliability—might hinder women’s understanding that they should make a personal, informed decision about screening. We offer arguments for a renewed recognition and use of informed consent compared to informed choice, and for a focus on value-consistent choices and personalized informational preferences. We argue for a three-step counselling model in which three decision moments are distinguished and differently addressed: (1) professionals explore women’s values concerning whether and why they wish to know whether their baby has a genetic disorder; (2) women receive layered medical-technical information and are asked to make a decision about screening; (3) during post-test counselling, women are supported in decision-making about the continuation or termination of their pregnancy. This model might also be applicable in other fields of genetic (pre-test) counselling, where techniques for expanding genome analysis and burdensome test-outcomes challenge counselling of patients.     

Elevated incubation temperature improves later-life swimming endurance in juvenile Chinook salmon,Oncorhynchus tshawytscha

The effect of incubation and rearing temperature on muscle development and swimming endurance under a high-intensity swimming test was investigated in juvenile Chinook salmon (Oncorhynchus tshawytscha) in a hatchery experiment. After controlling for the effects of fork length (L_F) and parental identity, times to fatigue of fish were higher when fish were incubated or reared at warmer temperatures. Significant differences among combinations of pre- and post-emergence temperatures conformed to 15–15°C > 15–9°C > 9–9°C > 7–9°C > 7–7°C in 2011 when swimming tests were conducted at 300 accumulated temperature units post-emergence and 15–9°C > (7–9°C = 7–7°C) in 2012 when swimming tests were conducted at an L_F of c. 40 mm. The combination of pre- and post-emergence temperatures also affected the number and size of muscle fibres, with differences among temperature treatments in mean fibre cross-sectional area persisting after controlling for L_F and parental effects. Nonetheless, neither fibre number nor fibre size accounted for significant variation in swimming endurance. Thus, thermal carryover effects on swimming endurance were not mediated by thermal imprinting of muscle structure. This is the first study to test how temperature, body size and muscle structure interact to affect swimming endurance during early development in salmon.