Solubility of nonylphenol and nonylphenol ethoxylates. On the possible role of micelles

The water solubility of nonylphenol (NP) has been estimated to be 4.9 +/- 0.4 mg/l corresponding to (2.22 +/- 0.18) x 10(-5) mol/l at 25 degrees C using shake flask and surface tension techniques. The low solubility in combination with an observed rather slow dissolution process will limit the leachability of NP in the terrestrial environment. Based on indirect evidence, it is suggested that NP, in contrast to nonylphenol ethoxylate (NPEO) with, e.g., 12 ethoxylate moieties, is not subject to micelle formation, and as such does not constitute a potential vehicle for the transport of hydrophobic pollutants in the environment. For NPEOs with a very high number of ethoxy moieties, e.g., 100, the compounds appear water soluble without micelle formation.     

EFFECTIVENESS OF TIMBER HARVEST PRACTICES FOR CONTROLLING SEDIMENT RELATED WATER QUALITY IMPACTS1

ABSTRACT: Timber harvest best management practices (BMPs) in Washington State were evaluated to determine their effectiveness at achieving water quality standards pertaining to sediment related effects. A weight‐of‐evidence approach was used to determine BMP effectiveness based on assessment of erosion with sediment delivery to streams, physical disturbance of stream channels, and aquatic habitat conditions during the first two years following harvest. Stream buffers were effective at preventing chronic sediment delivery to streams and physical disturbance of stream channels. Practices for ground‐based harvest and cable yarding in the vicinity of small streams without buffers were ineffective or only partially effective at preventing water quality impacts. The primary operational factors influencing BMP effectiveness were: the proximity of ground disturbing activities to streams; presence or absence of designated stream buffers; the use of special timber falling and yarding practices intended to minimize physical disturbance of stream channels; and timing of harvest to occur during snow cover or frozen ground conditions. Important site factors included the density of small streams at harvest sites and the steepness of inner stream valley slopes. Recommendations are given for practices that provide a high confidence of achieving water quality standards by preventing chronic sediment delivery and avoiding direct stream channel disturbance.     

Variability in host plant chemistry: behavioural responses and life-history parameters of the Colorado potato beetle (Leptinotarsa decemlineata)

Summary. Many studies investigating effects of plant chemicals on herbivore performance have reported contradictory results, perhaps because of possible interaction between different chemicals. Also, a herbivore’s performance is not necessarily consistent with its food or oviposition preference. Our aim was to investigate simultaneously antibiosis (larval growth and survival) and antixenosis (oviposition and feeding preferences) responses in herbivore to three plant chemicals, of which one is expected to have positive and two are expected to have negative effects. Antibiosis was measured by correlating the nitrogen and glycoalkaloid levels in host plants to the survival and adult size of Leptinotarsa decemlineata, by rearing larvae on whole plants of three potato varieties. Although host plants differed in their glycoalkaloid levels, survival rate and adult body size did not differ among beetles reared on different potato varieties. This suggests that beetles are quite robust for differences in both foliar α-chaconine and foliar α-solanine content. However, differences in antixenosis were found although they could not be directly predicted from the leaf chemistry. Females preferred to lay their eggs on the variety with high α-solanine content (Nevsky) towards which males showed a tendency to feeding preference. Overall, our results confirm that beetles are well adapted to the chemical defences of potato plants as potato varieties did not significantly affect beetle performance, but differences in oviposition preference may still result in major differences in the amount of damage inflicted on plants in the fields.     

The Nottingham Cycle-friendly Employers Project: lessons for encouraging cycle commuting

The Nottingham Cycle Friendly Employers Project studied the effectiveness of measures to promote cycling to work by eight large city employers under the 1995 governmentfunded Cycle Challenge. Progress was monitored by 'before' and 'after' surveys, by examination of the measures, and by discussions with the employers. Overall cycling awareness and activity were increased by the project: 42% of employees said their cycle commuting had increased. The main influences, about equally, were providing workplace cycling facilities, a house or job move making cycling more attractive, and heightened awareness of the importance of regular exercise for health. The most welcomed and best used measures were secure cycle parking, showering and changing facilities, and cycle purchase loans.     

Presentation of ventriculomegaly at 11–14 weeks of gestation: An analysis of longitudinal data

Objectives

The aim of this study was to examine the value of the sonographic measurements of the choroid plexus and the lateral ventricles at 11–14 gestational weeks in fetuses that had the diagnosis of second-trimester ventriculomegaly (VM) as a clinical reference.

Methods

The standard axial plane used for biparietal diameter measurement from 2D stored images in the first trimester was used to calculate the ratio between the choroid plexus and lateral ventricle diameter (PDVDR), the choroid plexus and lateral ventricle length (PLVLR) and the choroid plexus and lateral ventricle area (PAVAR) in 100 normal and 15 fetuses diagnosed with second-trimester VM.

Results

In fetuses with VM, the measurements of PDVDR, PLVLR and PAVAR were all significantly smaller compared to normal fetuses (p = < 0.001, <0.001, <0.01). Four out of seven cases with mild VM had measurements below the 5th percentile (57%). 75% of cases with moderate or severe VM had at least one measurement below the 5th percentile.

Conclusions

Since the axial plane of the fetal head is obtained in all first-trimester routine screenings, the measurements of PDVDR, PLVLR and PAVAR could easily be integrated into routine examinations for an early detection of VM.     

The value of echocardiography and Doppler in the prediction of fetal demise after laser coagulation for TTTS: A systematic review and meta-analysis

This study aimed to investigate the value of echocardiography and Doppler before fetoscopic laser coagulation for twin-twin transfusion syndrome (TTTS) in the prediction of intrauterine fetal demise (IUFD). We performed a systematic review and meta-analysis to compare preoperative parameters between fetuses with and without demise after laser surgery. Eighteen studies were included. Recipient twins have an increased risk of demise in case of preoperative absent/reversed flow (A/REDF) in the umbilical artery (odds ratio [OR] 2.76, 95% confidence interval [CI], 1.78-4.28), absent or reversed a-wave in the ductus venosus (OR 2.32, 95% CI, 1.70-3.16), or a middle cerebral artery peak systolic velocity > 1.5 multiples of the median (MoM) (OR 7.59, 95% CI, 2.56-22.46). In donors, only A/REDF in the umbilical artery (OR 3.40, 95% CI, 2.68-4.32) and absent or reversed a-wave in the ductus venosus (OR 1.66, 95% CI, 1.12-2.47) were associated with IUFD. No association was found between donor-IUFD and preoperative myocardial performance index (MPI). Two studies found an association between abnormal MPI and recipient demise. With this study, we have identified a set of preoperative Doppler parameters predictive of fetal demise after laser surgery. More research is needed to assess the utility of preoperative echocardiographic parameters such as the MPI in predicting IUFD.     

纳米二氧化钛在老化环境条件下对铜诱导毒性的影响

纳米二氧化钛颗粒(nTiO₂)可以通过吸附表层水中共生重金属来改变它们对淡水无脊椎动物的毒性。然而,影响这种交互过程的几种环境因子的相对重要性仍不清楚。因此,本研究通过连续72 h的培养试验,评估了老化对Cu与nTiO₂对大型蚤Daphnia magna联合急性毒性的影响。在老化过程中,对老化时间以及离子强度、pH值和不同质量有机物质等因子都进行了考察。研究结果表明,尽管影响效应的大小不同,nTiO₂的存在往往减少了老化后Cu对大型蚤的诱发毒性,在没有nTiO₂的情况下,Cu对大型蚤急性毒性的EC₅₀值提高了3倍之多。此外,各种形态Cu的形成受到介质中的离子组成、pH值以及有机添加剂存在的影响,这一过程受到极大的调控,并随着老化时间对大型蚤生态毒性的响应有一定影响。尽管如此,该研究的结论对nTiO₂在淡水生态系统中不同环境条件下,改变重金属诱发毒性的潜在作用提供了有力的支持。然而,这种模式需要进一步验证,比如结合不同性质的重金属离子与不同的环境因素,如紫外线照射。
精选自Ricki R. Rosenfeldt, Frank Seitz, Ann-Cathrin Haigis, Johanna H?ger, Jochen P. Zubrod, Ralf Schulz, Mirco Bundschuh. Nanosized titanium dioxide influences copper induced toxicity during aging as a function of environmental conditions. Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1766–1774, July 2016. DOI: 10.1002/etc.3325
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3325/full