Rapid karyotyping in prenatal diagnosis: A comparative study of the ‘pipette method’ and the ‘in situ’ technique for chromosome harvesting

Rapid karyotyping in the second and third trimesters has important implications for the management of pregnancies at risk. From September 1985 to March 1992, 735 amniotic fluid samples sent to our laboratory for rapid karyotyping from 64 different diagnostic centres of the Federal Republic of Germany were included in a comparative study on harvesting for chromosome analysis using the ‘pipette method’ or the ‘in situ’ technique. The average time between preparation of the amniotic fluid and verbal notification of the analysed karyotype was 5·41 days. The ‘pipette method’ needed on average 4·65 days, and the ‘in situ’ technique 5·97 days. In comparison with other more invasive techniques available for rapid karyotyping such as cordocentesis and placental biopsy, amniocentesis and subsequent chromosome harvesting using the ‘pipette method’ and/or the ‘in situ’ technique proved very useful and efficient. The overall incidence of chromosome aberrations was 15·3 per cent. The high rate of structural chromosome aberrations and uncommon aneuploidies found in our investigation (12 per cent) indicates that for rapid karyotyping in the second and third trimesters, conventional cytogenetic techniques cannot be replaced by faster techniques based on fluorescent in situ hybridization on interphase cells in the near future.     

Zur Frage der Bedeutung hormoneller Beziehungen bei der Insektenmetamorphose

The Science of Nature -     

Optical properties of selected plants from a tropical mountain ecosystem - Traits for plant functional types to parametrize a land surface model

The optical properties (reflectance and transmittance) of selected leaves from a tropical mountain rainforest in southern Ecuador are determined to parametrize optical traits of plant functional types (PFT) of a state of the art land model (Community Land Model, CLM). 46 spatially dominating species are selected from 4 different forest types, the subpáramo and a succession stage of pasture areas representing ecologically predefined functional types within the study area. Measurements are conducted under a standardized experimental setup with a field spectrometer covering the radiation between 305 and 1305 nm. The results of the optical properties of all species are checked for similarity by cluster analysis and are compared to the composition of species of the predefined PFTs. Furthermore the results are compared to other studies, the default values for the globally defined PFT of tropical evergreen trees in the CLM and another forest growth model operated in the same study area. The results show that the clusters aggregated by the reflectance, transmittance or combined properties do not represent the predefined PFTs. The values of the other studies suggest a reassessment of the experimental setup for the transmittance measurements. Nevertheless, new reflectance values for the regionalized PFTs can be determined. The optical values differ from the CLM-PFT of tropical evergreen trees, and new values for the reflectance are recommended.     

Influence of altitude concerning the contamination of humus soils in the German Alps: a data evaluation approach using PyHasse

Background, aim and scope  

In an international project named MONARPOP (Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants), selected chemicals in different environmental media were analysed in the years 2004 and 2005. Seventeen pesticides were chosen and analysed in humus and mineral soil in the German Alps. The samples were taken at different altitudes.     

Effect of audits on the extent of compliance with wastewater discharge limits

This study explores the effect of environmental self-audits (“audits”), which represent an important type of environmental management system practice, on the extent of facilities’ compliance with wastewater discharge limits. Theoretically, audits may (1) improve compliance by enhancing the effectiveness of treatment technologies and pollution prevention methods, (2) undermine compliance by distracting facilities’ personnel with audit-related administrative burdens, or (3) not influence compliance because these effects neutralize each other. By examining the extent of compliance, our study’s results reflect both improvement toward and beyond compliance. By assessing compliance with multiple pollutants separately, our study examines whether audits influence the control of different pollutants uniformly. Lastly, we employ a dynamic panel estimator, which allows us to explore whether facilities adjust their discharges dynamically, while controlling for any inertia in facilities’ pollution control systems. Our study empirically examines the U.S. chemical manufacturing sector between 1999 and 2001 using survey and publicly available EPA data.     

Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China

To better understand the diversity of metal resistance genetic determinant from microbes that survived atmetal tailings in northwest of China, a highly elevated level of heavymetal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria (PGPB). It shows that: Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF (Cation Diffusion Facilitator), HupE/UreJ and CHR (chromate ion transporter) family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative CopA/CueO system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while ZntA transporter, assisted with putative CzcD, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid (IAA) secretion, indicating a potential in-site phytoremediation usage in themining tailing regions of China.     

The post-Bhopal and post-9/11 transformations in chemical emergency prevention and response policy in the United States

The United States' approach to incident prevention and response to hazardous chemical facilities has undergone two major transformations in the last 20 years. The first was triggered by the Bhopal tragedy in 1984, which led to major changes within the US chemical industry and a series of Federal laws and regulations intended to prevent major chemical accidents. A more recent transformation is currently underway in the wake of the 9/11 attacks on New York and Washington. It involves the advent of various security-related requirements affecting many of the same facilities covered under the existing accident prevention rules. This paper provides an overview of these transformations and their impacts.     

Photodegradation of the antibiotic spiramycin studied by high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry

The degradation of spiramycin induced by ultraviolet (UV) irradiation was studied at pH 3–4, 6–7 and 8–9 using high-performance liquid chromatography-electrospray ionization-quadrupole time-of-flight mass spectrometry. Furthermore, the influence of hydrogen peroxide and oxygen on the photodegradation was investigated. Three degradation products were observed in the presence of oxygen and four in the absence of oxygen. The degradation kinetics were monitored as mass area-time curves, analyzed and described using subsequent follow-up reaction first-order models. The m/z values of the degradation products were determined to be 160, 322 and 366, the latter representing two separate products, the sugar moieties of spiramycin. Remainders of the macrocycle or the intact lactone ring of spiramycin were not observed, since the conjugated π-electron system was assumed photoexcited and thus undergoing photodegradation and fast destruction of the ring. The kinetic of the degradation of spiramycin itself was described using a first-order model. The degradation was accelerated upon addition of hydrogen peroxide. In contrast, systematic acceleration depending on pH could not be found. The absence of oxygen did not lead to any significant acceleration. The findings are interpreted in terms of the effectiveness of advanced oxidation processes and their potential use as a fourth purification step in wastewater treatment plants.