Oxidative degradation of 2,4-xylidine by photosensitization with 2,4,6-triphenylpyrylium: homogeneous and heterogeneous catalysis

The possibility of using zeolites containing the 2,4,6-triphenylpyrylium cation as photocatalysts for the degradation of pollutants has been tested on aqueous xylidine (2,4-dimethylaniline) solutions as models for contaminated wastewaters. The influence of the photocatalyst and substrate concentrations on xylidine oxidation has been investigated in homogeneous solution, by performing a series of experiments chosen according to the experimental design methodology (Doehlert uniform array). The empirical models and the corresponding response surfaces obtained from data analysis have been used for simulating and predicting degradation efficiency. The results have shown that conversion increases with increasing amounts of photocatalyst and decreasing concentration of the model pollutant. The fluorescence of 2,4,6-triphenylpyrylium was quenched by xylidine with a rate constant k(q) of 3.1x10(9)M(-1)s(-1). This result suggests a direct electron transfer between the excited pyrylium salt and xylidine. Because of the limited stability of the photocatalyst in homogeneous media, a pyrylium containing Y-zeolite has been tested for the photocatalytic oxidation of xylidine under heterogeneous conditions. The results suggest that the supported catalyst has a much improved stability and that xylidine oxidation rates remain nearly constant during the whole reaction time. An additional advantage of the pyrylium containing zeolite photocatalyst is that it can be recycled and used for further experiments.     

Doppler echocardiographic diagnosis of intrauterine closure of the ductus arteriosus

A case of in utero closure of the ductus arteriosus was detected by Doppler echocardio-graphy at 31 weeks of gestation. It presented as a non-hydropic distressed fetus with ultrasound detection of tricuspid regurgitation. Pulsed Doppler ultrasound showed markedly decreased blood flow through the tricuspid and pulmonary valves and absent blood flow at the ductus arteriosus. These, as well as the resultant increased right-to-left shunting across the foramen ovale, were reaffirmed by colour flow mapping.     

The Use of Low-Level Jets by Migrating Birds

 Birds flying at high altitudes have occasionally been observed above mountain areas and the open sea. For the first time the regular occurrence of migrating birds flying within a low-level jet at heights of 5000 to almost 9000 m asl. have now been verified by radar above the Negev desert in southern Israel. Tracks of rather large birds with wing-beat frequencies of 5–6 Hz were measured to have horizontal flight speeds up to 50 m/s. Visual observations, seasonal occurrence, and wing-beat frequencies allowed to associate them with small species of the order Ciconiiformes (mainly Ardeidae) and possibly with members of the Laro-Limicolae group. These wading birds seem prone to continuing nocturnal migration into daytime under favorable conditions and to make use of high wind speeds at sometimes extreme altitudes. Received: 21 June 1999 / Accepted in revised form: 26 August 1999     

Chromosome mosaicism of the placenta—a cause of developmental failure of the fetus?

Fourteen (2.5 per cent) of 568 chromosome preparations after CVS showed discrepancies between the placental and fetal karyotype, mainly due to placental mosaicism. The presence of a second cell line within the placenta was confirmed in all but one case, in which cytogenetic reinvestigations were carried out. Our clinical data indicate that severe developmental retardation in the newborn is not to be expected if only the placenta carries the chromosomally abnormal cell line.     

建立室内实验程序用于量化鸟类对种子消耗量的杀虫剂处理效应

种衣剂中使用的杀虫剂会影响鸟类对种子的消耗量,从而影响鸟类的实际暴露风险。虽然量化这种对消耗量的影响目前不被考虑在环境风险评估中,但这是一个潜在的选择,例如在比较不同农药的暴露风险时应予以考虑。这种方法可以突出用于防止鸟类服用致死或亚致死剂量的杀虫剂。为了制定一个标准,我们在已建立的笔试方法的基础上开发了一个室内测试程序,包括饥饿期的“两选择”和“无选择”阶段。测试期间采用动物福利的最高标准。利用统计方法确定最合适的重复次数并分析最终结果。杀虫剂对种子消耗量的影响用处理后种子与未处理种子消耗的比率表示。该消耗因子可作为种子处理的鸟类风险评估中的回避因子。 作为案例,我们提出了一个获得绿雀（Carduelis chloris）和日本鹌鹑（Coturnix japonica）对未处理和使用杀真菌剂处理的油菜籽（Brassica napus）的种子和特定物种消耗量因子的试验程序。总体来说,两种鸟类的体质都没有受到试验程序的负面影响。试验程序适用于显示预期消耗模式的差异,例如在“两选择”试验中比在“无选择”试验中对经过杀真菌剂处理的种子有更高的避免性。而种子消耗量在不同物种和杀真菌剂处理组有差别,这使得我们可以对不同杀真菌剂的规避效应进行排序。使用本文所提出的标准程序可以针对更多鸟类物种得到具有可比性的农药和物种特定的消费因子。     

Community vulnerability and resilience in disaster risk reduction: an example from Phojal Nalla,Himachal Pradesh,India

International Disaster Risk Reduction Frameworks and Indian Plans advocate shared responsibility for reducing disaster risk, in which community vulnerability and resilience conditions are central. This paper presents a case study from the Indian Himalaya (Kullu District) of community vulnerability and resilience conditions following damaging floods, primarily the 1994 Phojal Nalla flood, through the concepts of community heritage and capital. Data were collected in the period 2013–2016, using semi-structured interviews (n?=?129), village reconnaissance and archival/contemporary data searches. The connections between heritage, capital, vulnerability and resilience are complex, but results demonstrate ‘knowledge’ is the principal driver of resilience conditions, via facets of heritage (e.g. religious infrastructure and activities, traditional architectural vernacular, and multi-generational attachments to place) and capital (e.g. income diversification, access to communication technologies, societal welfare measures and positive interactions with water). Persisting vulnerabilities stem from differential access to and implementation of best practice knowledge, governed by social, economic and political conditions. Further improvements in risk reduction require greater consideration of the following: (1) the integration of community local knowledge into the overall disaster management process; (2) the opportunities offered by mobile phone and other technologies for generating and sharing knowledge across society; and (3) the value of under-utilised knowledge of past disaster events, assembled from a systematic evaluation of oral, documentary and landscape evidence, to risk reduction.     

<Emphasis Type="Italic">Mesorhizobium</Emphasis> bacterial strains isolated from the legume <Emphasis Type="Italic">Lotus corniculatus</Emphasis> are an alternative source for the production of polyhydroxyalkanoates (PHAs) to obtain bioplastics

Polyhydroxyalkanoic acids (PHAs) are natural polyesters that can be used to produce bioplastics which are biodegradable. Numerous microorganisms accumulate PHAs as energy reserves. Combinations of different PHAs monomers lead to the production of bioplastics with very different properties. In the present work, we show the capability of strains belonging to various phylogenetic lineages within the genus Mesorhizobium, isolated from Lotus corniculatus nodules, to produce different PHA monomers. Among our strains, we found the production of 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxydodecanoate, and 3-hydroxyhexadecanoate. Most of the PHA-positive strains were phylogenetically related to the species M. jarvisii. However, our findings suggest that the ability to produce different monomers forming PHAs is strain-dependent.     

Newborns and low to moderate prenatal environmental lead exposure: might fathers be the key?

This study is part of the BioMadrid Project, a bio-monitoring study designed to assess pollutants in the environment surrounding children born in the Madrid region. Our aim in this report is to evaluate the association between prenatal lead exposure and fetal development using three biological samples (maternal and paternal blood lead at around 34 weeks of gestation as well as cord blood lead levels), three biomarkers of effect in cord blood peripheral lymphocytes (micronucleus in binucleated cells, nucleoplasmic bridges, and nuclear buds), and different anthropometrical characteristics at birth. Maternal and cord blood lead were not associated with newborn measurements or genotoxicity biomarkers. In contrast, increases in father blood lead were coupled with lower weight (mean difference (MD), ?110.8 g; 95 % confidence intervals (95%CI), ?235.6 to 6.00; p?<?0.10) and shorter abdominal (MD, ?0.81 cm; 95%CI, ?1.64 to 0.00; p?<?0.05) and cephalic (MD, ?0.32 cm; 95%CI, ?0.65 to 0.00; p?<?0.05) circumferences at birth as well as with the presence of nucleoplasmic bridges (odds ratio, 1.03; 95%CI, 1.00 to 1.06; p?<?0.05) and nuclear buds (odds ratio, 1.02; 95%CI, 0.99 to 1.04; p?<?0.10). These associations were mainly confined to female babies, in whom paternal lead was also inversely associated with length. Our results support the hypothesis that paternal lead exposure may be affecting the development of newborns.